/*------------------------------------------------------------------------- * * pl_exec.c - Executor for the PL/pgSQL * procedural language * * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/pl/plpgsql/src/pl_exec.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include "access/detoast.h" #include "access/htup_details.h" #include "access/transam.h" #include "access/tupconvert.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" #include "commands/defrem.h" #include "executor/execExpr.h" #include "executor/spi.h" #include "executor/tstoreReceiver.h" #include "funcapi.h" #include "mb/stringinfo_mb.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" #include "optimizer/optimizer.h" #include "parser/parse_coerce.h" #include "parser/parse_type.h" #include "parser/scansup.h" #include "plpgsql.h" #include "storage/proc.h" #include "tcop/cmdtag.h" #include "tcop/pquery.h" #include "tcop/tcopprot.h" #include "tcop/utility.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/datum.h" #include "utils/fmgroids.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/rel.h" #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/typcache.h" /* * All plpgsql function executions within a single transaction share the same * executor EState for evaluating "simple" expressions. Each function call * creates its own "eval_econtext" ExprContext within this estate for * per-evaluation workspace. eval_econtext is freed at normal function exit, * and the EState is freed at transaction end (in case of error, we assume * that the abort mechanisms clean it all up). Furthermore, any exception * block within a function has to have its own eval_econtext separate from * the containing function's, so that we can clean up ExprContext callbacks * properly at subtransaction exit. We maintain a stack that tracks the * individual econtexts so that we can clean up correctly at subxact exit. * * This arrangement is a bit tedious to maintain, but it's worth the trouble * so that we don't have to re-prepare simple expressions on each trip through * a function. (We assume the case to optimize is many repetitions of a * function within a transaction.) * * However, there's no value in trying to amortize simple expression setup * across multiple executions of a DO block (inline code block), since there * can never be any. If we use the shared EState for a DO block, the expr * state trees are effectively leaked till end of transaction, and that can * add up if the user keeps on submitting DO blocks. Therefore, each DO block * has its own simple-expression EState, which is cleaned up at exit from * plpgsql_inline_handler(). DO blocks still use the simple_econtext_stack, * though, so that subxact abort cleanup does the right thing. * * (However, if a DO block executes COMMIT or ROLLBACK, then exec_stmt_commit * or exec_stmt_rollback will unlink it from the DO's simple-expression EState * and create a new shared EState that will be used thenceforth. The original * EState will be cleaned up when we get back to plpgsql_inline_handler. This * is a bit ugly, but it isn't worth doing better, since scenarios like this * can't result in indefinite accumulation of state trees.) */ typedef struct SimpleEcontextStackEntry { ExprContext *stack_econtext; /* a stacked econtext */ SubTransactionId xact_subxid; /* ID for current subxact */ struct SimpleEcontextStackEntry *next; /* next stack entry up */ } SimpleEcontextStackEntry; static EState *shared_simple_eval_estate = NULL; static SimpleEcontextStackEntry *simple_econtext_stack = NULL; /* * In addition to the shared simple-eval EState, we have a shared resource * owner that holds refcounts on the CachedPlans for any "simple" expressions * we have evaluated in the current transaction. This allows us to avoid * continually grabbing and releasing a plan refcount when a simple expression * is used over and over. (DO blocks use their own resowner, in exactly the * same way described above for shared_simple_eval_estate.) */ static ResourceOwner shared_simple_eval_resowner = NULL; /* * Memory management within a plpgsql function generally works with three * contexts: * * 1. Function-call-lifespan data, such as variable values, is kept in the * "main" context, a/k/a the "SPI Proc" context established by SPI_connect(). * This is usually the CurrentMemoryContext while running code in this module * (which is not good, because careless coding can easily cause * function-lifespan memory leaks, but we live with it for now). * * 2. Some statement-execution routines need statement-lifespan workspace. * A suitable context is created on-demand by get_stmt_mcontext(), and must * be reset at the end of the requesting routine. Error recovery will clean * it up automatically. Nested statements requiring statement-lifespan * workspace will result in a stack of such contexts, see push_stmt_mcontext(). * * 3. We use the eval_econtext's per-tuple memory context for expression * evaluation, and as a general-purpose workspace for short-lived allocations. * Such allocations usually aren't explicitly freed, but are left to be * cleaned up by a context reset, typically done by exec_eval_cleanup(). * * These macros are for use in making short-lived allocations: */ #define get_eval_mcontext(estate) \ ((estate)->eval_econtext->ecxt_per_tuple_memory) #define eval_mcontext_alloc(estate, sz) \ MemoryContextAlloc(get_eval_mcontext(estate), sz) #define eval_mcontext_alloc0(estate, sz) \ MemoryContextAllocZero(get_eval_mcontext(estate), sz) /* * We use two session-wide hash tables for caching cast information. * * cast_expr_hash entries (of type plpgsql_CastExprHashEntry) hold compiled * expression trees for casts. These survive for the life of the session and * are shared across all PL/pgSQL functions and DO blocks. At some point it * might be worth invalidating them after pg_cast changes, but for the moment * we don't bother. * * There is a separate hash table shared_cast_hash (with entries of type * plpgsql_CastHashEntry) containing evaluation state trees for these * expressions, which are managed in the same way as simple expressions * (i.e., we assume cast expressions are always simple). * * As with simple expressions, DO blocks don't use the shared_cast_hash table * but must have their own evaluation state trees. This isn't ideal, but we * don't want to deal with multiple simple_eval_estates within a DO block. */ typedef struct /* lookup key for cast info */ { /* NB: we assume this struct contains no padding bytes */ Oid srctype; /* source type for cast */ Oid dsttype; /* destination type for cast */ int32 srctypmod; /* source typmod for cast */ int32 dsttypmod; /* destination typmod for cast */ } plpgsql_CastHashKey; typedef struct /* cast_expr_hash table entry */ { plpgsql_CastHashKey key; /* hash key --- MUST BE FIRST */ Expr *cast_expr; /* cast expression, or NULL if no-op cast */ CachedExpression *cast_cexpr; /* cached expression backing the above */ } plpgsql_CastExprHashEntry; typedef struct /* cast_hash table entry */ { plpgsql_CastHashKey key; /* hash key --- MUST BE FIRST */ plpgsql_CastExprHashEntry *cast_centry; /* link to matching expr entry */ /* ExprState is valid only when cast_lxid matches current LXID */ ExprState *cast_exprstate; /* expression's eval tree */ bool cast_in_use; /* true while we're executing eval tree */ LocalTransactionId cast_lxid; } plpgsql_CastHashEntry; static HTAB *cast_expr_hash = NULL; static HTAB *shared_cast_hash = NULL; /* * LOOP_RC_PROCESSING encapsulates common logic for looping statements to * handle return/exit/continue result codes from the loop body statement(s). * It's meant to be used like this: * * int rc = PLPGSQL_RC_OK; * for (...) * { * ... * rc = exec_stmts(estate, stmt->body); * LOOP_RC_PROCESSING(stmt->label, break); * ... * } * return rc; * * If execution of the loop should terminate, LOOP_RC_PROCESSING will execute * "exit_action" (typically a "break" or "goto"), after updating "rc" to the * value the current statement should return. If execution should continue, * LOOP_RC_PROCESSING will do nothing except reset "rc" to PLPGSQL_RC_OK. * * estate and rc are implicit arguments to the macro. * estate->exitlabel is examined and possibly updated. */ #define LOOP_RC_PROCESSING(looplabel, exit_action) \ if (rc == PLPGSQL_RC_RETURN) \ { \ /* RETURN, so propagate RC_RETURN out */ \ exit_action; \ } \ else if (rc == PLPGSQL_RC_EXIT) \ { \ if (estate->exitlabel == NULL) \ { \ /* unlabeled EXIT terminates this loop */ \ rc = PLPGSQL_RC_OK; \ exit_action; \ } \ else if ((looplabel) != NULL && \ strcmp(looplabel, estate->exitlabel) == 0) \ { \ /* labeled EXIT matching this loop, so terminate loop */ \ estate->exitlabel = NULL; \ rc = PLPGSQL_RC_OK; \ exit_action; \ } \ else \ { \ /* non-matching labeled EXIT, propagate RC_EXIT out */ \ exit_action; \ } \ } \ else if (rc == PLPGSQL_RC_CONTINUE) \ { \ if (estate->exitlabel == NULL) \ { \ /* unlabeled CONTINUE matches this loop, so continue in loop */ \ rc = PLPGSQL_RC_OK; \ } \ else if ((looplabel) != NULL && \ strcmp(looplabel, estate->exitlabel) == 0) \ { \ /* labeled CONTINUE matching this loop, so continue in loop */ \ estate->exitlabel = NULL; \ rc = PLPGSQL_RC_OK; \ } \ else \ { \ /* non-matching labeled CONTINUE, propagate RC_CONTINUE out */ \ exit_action; \ } \ } \ else \ Assert(rc == PLPGSQL_RC_OK) /************************************************************ * Local function forward declarations ************************************************************/ static void coerce_function_result_tuple(PLpgSQL_execstate *estate, TupleDesc tupdesc); static void plpgsql_exec_error_callback(void *arg); static void copy_plpgsql_datums(PLpgSQL_execstate *estate, PLpgSQL_function *func); static void plpgsql_fulfill_promise(PLpgSQL_execstate *estate, PLpgSQL_var *var); static MemoryContext get_stmt_mcontext(PLpgSQL_execstate *estate); static void push_stmt_mcontext(PLpgSQL_execstate *estate); static void pop_stmt_mcontext(PLpgSQL_execstate *estate); static int exec_toplevel_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block); static int exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block); static int exec_stmts(PLpgSQL_execstate *estate, List *stmts); static int exec_stmt_assign(PLpgSQL_execstate *estate, PLpgSQL_stmt_assign *stmt); static int exec_stmt_perform(PLpgSQL_execstate *estate, PLpgSQL_stmt_perform *stmt); static int exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt); static int exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt); static int exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt); static int exec_stmt_case(PLpgSQL_execstate *estate, PLpgSQL_stmt_case *stmt); static int exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt); static int exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt); static int exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt); static int exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt); static int exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt); static int exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt); static int exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt); static int exec_stmt_fetch(PLpgSQL_execstate *estate, PLpgSQL_stmt_fetch *stmt); static int exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt); static int exec_stmt_exit(PLpgSQL_execstate *estate, PLpgSQL_stmt_exit *stmt); static int exec_stmt_return(PLpgSQL_execstate *estate, PLpgSQL_stmt_return *stmt); static int exec_stmt_return_next(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_next *stmt); static int exec_stmt_return_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_query *stmt); static int exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt); static int exec_stmt_assert(PLpgSQL_execstate *estate, PLpgSQL_stmt_assert *stmt); static int exec_stmt_execsql(PLpgSQL_execstate *estate, PLpgSQL_stmt_execsql *stmt); static int exec_stmt_dynexecute(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynexecute *stmt); static int exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt); static int exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt); static int exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt); static void plpgsql_estate_setup(PLpgSQL_execstate *estate, PLpgSQL_function *func, ReturnSetInfo *rsi, EState *simple_eval_estate, ResourceOwner simple_eval_resowner); static void exec_eval_cleanup(PLpgSQL_execstate *estate); static void exec_prepare_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, int cursorOptions); static void exec_simple_check_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr); static void exec_save_simple_expr(PLpgSQL_expr *expr, CachedPlan *cplan); static void exec_check_rw_parameter(PLpgSQL_expr *expr); static void exec_check_assignable(PLpgSQL_execstate *estate, int dno); static bool exec_eval_simple_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, Datum *result, bool *isNull, Oid *rettype, int32 *rettypmod); static void exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target, PLpgSQL_expr *expr); static void exec_assign_c_string(PLpgSQL_execstate *estate, PLpgSQL_datum *target, const char *str); static void exec_assign_value(PLpgSQL_execstate *estate, PLpgSQL_datum *target, Datum value, bool isNull, Oid valtype, int32 valtypmod); static void exec_eval_datum(PLpgSQL_execstate *estate, PLpgSQL_datum *datum, Oid *typeid, int32 *typetypmod, Datum *value, bool *isnull); static int exec_eval_integer(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull); static bool exec_eval_boolean(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull); static Datum exec_eval_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull, Oid *rettype, int32 *rettypmod); static int exec_run_select(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, long maxtuples, Portal *portalP); static int exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt, Portal portal, bool prefetch_ok); static ParamListInfo setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr); static ParamExternData *plpgsql_param_fetch(ParamListInfo params, int paramid, bool speculative, ParamExternData *prm); static void plpgsql_param_compile(ParamListInfo params, Param *param, ExprState *state, Datum *resv, bool *resnull); static void plpgsql_param_eval_var(ExprState *state, ExprEvalStep *op, ExprContext *econtext); static void plpgsql_param_eval_var_ro(ExprState *state, ExprEvalStep *op, ExprContext *econtext); static void plpgsql_param_eval_recfield(ExprState *state, ExprEvalStep *op, ExprContext *econtext); static void plpgsql_param_eval_generic(ExprState *state, ExprEvalStep *op, ExprContext *econtext); static void plpgsql_param_eval_generic_ro(ExprState *state, ExprEvalStep *op, ExprContext *econtext); static void exec_move_row(PLpgSQL_execstate *estate, PLpgSQL_variable *target, HeapTuple tup, TupleDesc tupdesc); static void revalidate_rectypeid(PLpgSQL_rec *rec); static ExpandedRecordHeader *make_expanded_record_for_rec(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, TupleDesc srctupdesc, ExpandedRecordHeader *srcerh); static void exec_move_row_from_fields(PLpgSQL_execstate *estate, PLpgSQL_variable *target, ExpandedRecordHeader *newerh, Datum *values, bool *nulls, TupleDesc tupdesc); static bool compatible_tupdescs(TupleDesc src_tupdesc, TupleDesc dst_tupdesc); static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate, PLpgSQL_row *row, TupleDesc tupdesc); static TupleDesc deconstruct_composite_datum(Datum value, HeapTupleData *tmptup); static void exec_move_row_from_datum(PLpgSQL_execstate *estate, PLpgSQL_variable *target, Datum value); static void instantiate_empty_record_variable(PLpgSQL_execstate *estate, PLpgSQL_rec *rec); static char *convert_value_to_string(PLpgSQL_execstate *estate, Datum value, Oid valtype); static inline Datum exec_cast_value(PLpgSQL_execstate *estate, Datum value, bool *isnull, Oid valtype, int32 valtypmod, Oid reqtype, int32 reqtypmod); static Datum do_cast_value(PLpgSQL_execstate *estate, Datum value, bool *isnull, Oid valtype, int32 valtypmod, Oid reqtype, int32 reqtypmod); static plpgsql_CastHashEntry *get_cast_hashentry(PLpgSQL_execstate *estate, Oid srctype, int32 srctypmod, Oid dsttype, int32 dsttypmod); static void exec_init_tuple_store(PLpgSQL_execstate *estate); static void exec_set_found(PLpgSQL_execstate *estate, bool state); static void plpgsql_create_econtext(PLpgSQL_execstate *estate); static void plpgsql_destroy_econtext(PLpgSQL_execstate *estate); static void assign_simple_var(PLpgSQL_execstate *estate, PLpgSQL_var *var, Datum newvalue, bool isnull, bool freeable); static void assign_text_var(PLpgSQL_execstate *estate, PLpgSQL_var *var, const char *str); static void assign_record_var(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, ExpandedRecordHeader *erh); static ParamListInfo exec_eval_using_params(PLpgSQL_execstate *estate, List *params); static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *dynquery, List *params, const char *portalname, int cursorOptions); static char *format_expr_params(PLpgSQL_execstate *estate, const PLpgSQL_expr *expr); static char *format_preparedparamsdata(PLpgSQL_execstate *estate, ParamListInfo paramLI); static PLpgSQL_variable *make_callstmt_target(PLpgSQL_execstate *estate, PLpgSQL_expr *expr); /* ---------- * plpgsql_exec_function Called by the call handler for * function execution. * * This is also used to execute inline code blocks (DO blocks). The only * difference that this code is aware of is that for a DO block, we want * to use a private simple_eval_estate and a private simple_eval_resowner, * which are created and passed in by the caller. For regular functions, * pass NULL, which implies using shared_simple_eval_estate and * shared_simple_eval_resowner. (When using a private simple_eval_estate, * we must also use a private cast hashtable, but that's taken care of * within plpgsql_estate_setup.) * procedure_resowner is a resowner that will survive for the duration * of execution of this function/procedure. It is needed only if we * are doing non-atomic execution and there are CALL or DO statements * in the function; otherwise it can be NULL. We use it to hold refcounts * on the CALL/DO statements' plans. * ---------- */ Datum plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo, EState *simple_eval_estate, ResourceOwner simple_eval_resowner, ResourceOwner procedure_resowner, bool atomic) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int i; int rc; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo, simple_eval_estate, simple_eval_resowner); estate.procedure_resowner = procedure_resowner; estate.atomic = atomic; /* * Setup error traceback support for ereport() */ plerrcontext.callback = plpgsql_exec_error_callback; plerrcontext.arg = &estate; plerrcontext.previous = error_context_stack; error_context_stack = &plerrcontext; /* * Make local execution copies of all the datums */ estate.err_text = gettext_noop("during initialization of execution state"); copy_plpgsql_datums(&estate, func); /* * Store the actual call argument values into the appropriate variables */ estate.err_text = gettext_noop("while storing call arguments into local variables"); for (i = 0; i < func->fn_nargs; i++) { int n = func->fn_argvarnos[i]; switch (estate.datums[n]->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) estate.datums[n]; assign_simple_var(&estate, var, fcinfo->args[i].value, fcinfo->args[i].isnull, false); /* * Force any array-valued parameter to be stored in * expanded form in our local variable, in hopes of * improving efficiency of uses of the variable. (This is * a hack, really: why only arrays? Need more thought * about which cases are likely to win. See also * typisarray-specific heuristic in exec_assign_value.) * * Special cases: If passed a R/W expanded pointer, assume * we can commandeer the object rather than having to copy * it. If passed a R/O expanded pointer, just keep it as * the value of the variable for the moment. (We'll force * it to R/W if the variable gets modified, but that may * very well never happen.) */ if (!var->isnull && var->datatype->typisarray) { if (VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(var->value))) { /* take ownership of R/W object */ assign_simple_var(&estate, var, TransferExpandedObject(var->value, estate.datum_context), false, true); } else if (VARATT_IS_EXTERNAL_EXPANDED_RO(DatumGetPointer(var->value))) { /* R/O pointer, keep it as-is until assigned to */ } else { /* flat array, so force to expanded form */ assign_simple_var(&estate, var, expand_array(var->value, estate.datum_context, NULL), false, true); } } } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) estate.datums[n]; if (!fcinfo->args[i].isnull) { /* Assign row value from composite datum */ exec_move_row_from_datum(&estate, (PLpgSQL_variable *) rec, fcinfo->args[i].value); } else { /* If arg is null, set variable to null */ exec_move_row(&estate, (PLpgSQL_variable *) rec, NULL, NULL); } /* clean up after exec_move_row() */ exec_eval_cleanup(&estate); } break; default: /* Anything else should not be an argument variable */ elog(ERROR, "unrecognized dtype: %d", func->datums[i]->dtype); } } estate.err_text = gettext_noop("during function entry"); /* * Set the magic variable FOUND to false */ exec_set_found(&estate, false); /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg) ((*plpgsql_plugin_ptr)->func_beg) (&estate, func); /* * Now call the toplevel block of statements */ estate.err_text = NULL; rc = exec_toplevel_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_text = NULL; ereport(ERROR, (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT), errmsg("control reached end of function without RETURN"))); } /* * We got a return value - process it */ estate.err_text = gettext_noop("while casting return value to function's return type"); fcinfo->isnull = estate.retisnull; if (estate.retisset) { ReturnSetInfo *rsi = estate.rsi; /* Check caller can handle a set result */ if (!rsi || !IsA(rsi, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsi->allowedModes & SFRM_Materialize)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); rsi->returnMode = SFRM_Materialize; /* If we produced any tuples, send back the result */ if (estate.tuple_store) { MemoryContext oldcxt; rsi->setResult = estate.tuple_store; oldcxt = MemoryContextSwitchTo(estate.tuple_store_cxt); rsi->setDesc = CreateTupleDescCopy(estate.tuple_store_desc); MemoryContextSwitchTo(oldcxt); } estate.retval = (Datum) 0; fcinfo->isnull = true; } else if (!estate.retisnull) { /* * Cast result value to function's declared result type, and copy it * out to the upper executor memory context. We must treat tuple * results specially in order to deal with cases like rowtypes * involving dropped columns. */ if (estate.retistuple) { /* Don't need coercion if rowtype is known to match */ if (func->fn_rettype == estate.rettype && func->fn_rettype != RECORDOID) { /* * Copy the tuple result into upper executor memory context. * However, if we have a R/W expanded datum, we can just * transfer its ownership out to the upper context. */ estate.retval = SPI_datumTransfer(estate.retval, false, -1); } else { /* * Need to look up the expected result type. XXX would be * better to cache the tupdesc instead of repeating * get_call_result_type(), but the only easy place to save it * is in the PLpgSQL_function struct, and that's too * long-lived: composite types could change during the * existence of a PLpgSQL_function. */ Oid resultTypeId; TupleDesc tupdesc; switch (get_call_result_type(fcinfo, &resultTypeId, &tupdesc)) { case TYPEFUNC_COMPOSITE: /* got the expected result rowtype, now coerce it */ coerce_function_result_tuple(&estate, tupdesc); break; case TYPEFUNC_COMPOSITE_DOMAIN: /* got the expected result rowtype, now coerce it */ coerce_function_result_tuple(&estate, tupdesc); /* and check domain constraints */ /* XXX allowing caching here would be good, too */ domain_check(estate.retval, false, resultTypeId, NULL, NULL); break; case TYPEFUNC_RECORD: /* * Failed to determine actual type of RECORD. We * could raise an error here, but what this means in * practice is that the caller is expecting any old * generic rowtype, so we don't really need to be * restrictive. Pass back the generated result as-is. */ estate.retval = SPI_datumTransfer(estate.retval, false, -1); break; default: /* shouldn't get here if retistuple is true ... */ elog(ERROR, "return type must be a row type"); break; } } } else { /* Scalar case: use exec_cast_value */ estate.retval = exec_cast_value(&estate, estate.retval, &fcinfo->isnull, estate.rettype, -1, func->fn_rettype, -1); /* * If the function's return type isn't by value, copy the value * into upper executor memory context. However, if we have a R/W * expanded datum, we can just transfer its ownership out to the * upper executor context. */ if (!fcinfo->isnull && !func->fn_retbyval) estate.retval = SPI_datumTransfer(estate.retval, false, func->fn_rettyplen); } } else { /* * We're returning a NULL, which normally requires no conversion work * regardless of datatypes. But, if we are casting it to a domain * return type, we'd better check that the domain's constraints pass. */ if (func->fn_retisdomain) estate.retval = exec_cast_value(&estate, estate.retval, &fcinfo->isnull, estate.rettype, -1, func->fn_rettype, -1); } estate.err_text = gettext_noop("during function exit"); /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end) ((*plpgsql_plugin_ptr)->func_end) (&estate, func); /* Clean up any leftover temporary memory */ plpgsql_destroy_econtext(&estate); exec_eval_cleanup(&estate); /* stmt_mcontext will be destroyed when function's main context is */ /* * Pop the error context stack */ error_context_stack = plerrcontext.previous; /* * Return the function's result */ return estate.retval; } /* * Helper for plpgsql_exec_function: coerce composite result to the specified * tuple descriptor, and copy it out to upper executor memory. This is split * out mostly for cosmetic reasons --- the logic would be very deeply nested * otherwise. * * estate->retval is updated in-place. */ static void coerce_function_result_tuple(PLpgSQL_execstate *estate, TupleDesc tupdesc) { HeapTuple rettup; TupleDesc retdesc; TupleConversionMap *tupmap; /* We assume exec_stmt_return verified that result is composite */ Assert(type_is_rowtype(estate->rettype)); /* We can special-case expanded records for speed */ if (VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(estate->retval))) { ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(estate->retval); Assert(erh->er_magic == ER_MAGIC); /* Extract record's TupleDesc */ retdesc = expanded_record_get_tupdesc(erh); /* check rowtype compatibility */ tupmap = convert_tuples_by_position(retdesc, tupdesc, gettext_noop("returned record type does not match expected record type")); /* it might need conversion */ if (tupmap) { rettup = expanded_record_get_tuple(erh); Assert(rettup); rettup = execute_attr_map_tuple(rettup, tupmap); /* * Copy tuple to upper executor memory, as a tuple Datum. Make * sure it is labeled with the caller-supplied tuple type. */ estate->retval = PointerGetDatum(SPI_returntuple(rettup, tupdesc)); /* no need to free map, we're about to return anyway */ } else if (!(tupdesc->tdtypeid == erh->er_decltypeid || (tupdesc->tdtypeid == RECORDOID && !ExpandedRecordIsDomain(erh)))) { /* * The expanded record has the right physical tupdesc, but the * wrong type ID. (Typically, the expanded record is RECORDOID * but the function is declared to return a named composite type. * As in exec_move_row_from_datum, we don't allow returning a * composite-domain record from a function declared to return * RECORD.) So we must flatten the record to a tuple datum and * overwrite its type fields with the right thing. spi.c doesn't * provide any easy way to deal with this case, so we end up * duplicating the guts of datumCopy() :-( */ Size resultsize; HeapTupleHeader tuphdr; resultsize = EOH_get_flat_size(&erh->hdr); tuphdr = (HeapTupleHeader) SPI_palloc(resultsize); EOH_flatten_into(&erh->hdr, (void *) tuphdr, resultsize); HeapTupleHeaderSetTypeId(tuphdr, tupdesc->tdtypeid); HeapTupleHeaderSetTypMod(tuphdr, tupdesc->tdtypmod); estate->retval = PointerGetDatum(tuphdr); } else { /* * We need only copy result into upper executor memory context. * However, if we have a R/W expanded datum, we can just transfer * its ownership out to the upper executor context. */ estate->retval = SPI_datumTransfer(estate->retval, false, -1); } } else { /* Convert composite datum to a HeapTuple and TupleDesc */ HeapTupleData tmptup; retdesc = deconstruct_composite_datum(estate->retval, &tmptup); rettup = &tmptup; /* check rowtype compatibility */ tupmap = convert_tuples_by_position(retdesc, tupdesc, gettext_noop("returned record type does not match expected record type")); /* it might need conversion */ if (tupmap) rettup = execute_attr_map_tuple(rettup, tupmap); /* * Copy tuple to upper executor memory, as a tuple Datum. Make sure * it is labeled with the caller-supplied tuple type. */ estate->retval = PointerGetDatum(SPI_returntuple(rettup, tupdesc)); /* no need to free map, we're about to return anyway */ ReleaseTupleDesc(retdesc); } } /* ---------- * plpgsql_exec_trigger Called by the call handler for * trigger execution. * ---------- */ HeapTuple plpgsql_exec_trigger(PLpgSQL_function *func, TriggerData *trigdata) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int rc; TupleDesc tupdesc; PLpgSQL_rec *rec_new, *rec_old; HeapTuple rettup; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, NULL, NULL, NULL); estate.trigdata = trigdata; /* * Setup error traceback support for ereport() */ plerrcontext.callback = plpgsql_exec_error_callback; plerrcontext.arg = &estate; plerrcontext.previous = error_context_stack; error_context_stack = &plerrcontext; /* * Make local execution copies of all the datums */ estate.err_text = gettext_noop("during initialization of execution state"); copy_plpgsql_datums(&estate, func); /* * Put the OLD and NEW tuples into record variables * * We set up expanded records for both variables even though only one may * have a value. This allows record references to succeed in functions * that are used for multiple trigger types. For example, we might have a * test like "if (TG_OP = 'INSERT' and NEW.foo = 'xyz')", which should * work regardless of the current trigger type. If a value is actually * fetched from an unsupplied tuple, it will read as NULL. */ tupdesc = RelationGetDescr(trigdata->tg_relation); rec_new = (PLpgSQL_rec *) (estate.datums[func->new_varno]); rec_old = (PLpgSQL_rec *) (estate.datums[func->old_varno]); rec_new->erh = make_expanded_record_from_tupdesc(tupdesc, estate.datum_context); rec_old->erh = make_expanded_record_from_exprecord(rec_new->erh, estate.datum_context); if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) { /* * Per-statement triggers don't use OLD/NEW variables */ } else if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) { expanded_record_set_tuple(rec_new->erh, trigdata->tg_trigtuple, false, false); } else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) { expanded_record_set_tuple(rec_new->erh, trigdata->tg_newtuple, false, false); expanded_record_set_tuple(rec_old->erh, trigdata->tg_trigtuple, false, false); /* * In BEFORE trigger, stored generated columns are not computed yet, * so make them null in the NEW row. (Only needed in UPDATE branch; * in the INSERT case, they are already null, but in UPDATE, the field * still contains the old value.) Alternatively, we could construct a * whole new row structure without the generated columns, but this way * seems more efficient and potentially less confusing. */ if (tupdesc->constr && tupdesc->constr->has_generated_stored && TRIGGER_FIRED_BEFORE(trigdata->tg_event)) { for (int i = 0; i < tupdesc->natts; i++) if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_STORED) expanded_record_set_field_internal(rec_new->erh, i + 1, (Datum) 0, true, /* isnull */ false, false); } } else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) { expanded_record_set_tuple(rec_old->erh, trigdata->tg_trigtuple, false, false); } else elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, or UPDATE"); /* Make transition tables visible to this SPI connection */ rc = SPI_register_trigger_data(trigdata); Assert(rc >= 0); estate.err_text = gettext_noop("during function entry"); /* * Set the magic variable FOUND to false */ exec_set_found(&estate, false); /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg) ((*plpgsql_plugin_ptr)->func_beg) (&estate, func); /* * Now call the toplevel block of statements */ estate.err_text = NULL; rc = exec_toplevel_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_text = NULL; ereport(ERROR, (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT), errmsg("control reached end of trigger procedure without RETURN"))); } estate.err_text = gettext_noop("during function exit"); if (estate.retisset) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("trigger procedure cannot return a set"))); /* * Check that the returned tuple structure has the same attributes, the * relation that fired the trigger has. A per-statement trigger always * needs to return NULL, so we ignore any return value the function itself * produces (XXX: is this a good idea?) * * XXX This way it is possible, that the trigger returns a tuple where * attributes don't have the correct atttypmod's length. It's up to the * trigger's programmer to ensure that this doesn't happen. Jan */ if (estate.retisnull || !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) rettup = NULL; else { TupleDesc retdesc; TupleConversionMap *tupmap; /* We assume exec_stmt_return verified that result is composite */ Assert(type_is_rowtype(estate.rettype)); /* We can special-case expanded records for speed */ if (VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(estate.retval))) { ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(estate.retval); Assert(erh->er_magic == ER_MAGIC); /* Extract HeapTuple and TupleDesc */ rettup = expanded_record_get_tuple(erh); Assert(rettup); retdesc = expanded_record_get_tupdesc(erh); if (retdesc != RelationGetDescr(trigdata->tg_relation)) { /* check rowtype compatibility */ tupmap = convert_tuples_by_position(retdesc, RelationGetDescr(trigdata->tg_relation), gettext_noop("returned row structure does not match the structure of the triggering table")); /* it might need conversion */ if (tupmap) rettup = execute_attr_map_tuple(rettup, tupmap); /* no need to free map, we're about to return anyway */ } /* * Copy tuple to upper executor memory. But if user just did * "return new" or "return old" without changing anything, there's * no need to copy; we can return the original tuple (which will * save a few cycles in trigger.c as well as here). */ if (rettup != trigdata->tg_newtuple && rettup != trigdata->tg_trigtuple) rettup = SPI_copytuple(rettup); } else { /* Convert composite datum to a HeapTuple and TupleDesc */ HeapTupleData tmptup; retdesc = deconstruct_composite_datum(estate.retval, &tmptup); rettup = &tmptup; /* check rowtype compatibility */ tupmap = convert_tuples_by_position(retdesc, RelationGetDescr(trigdata->tg_relation), gettext_noop("returned row structure does not match the structure of the triggering table")); /* it might need conversion */ if (tupmap) rettup = execute_attr_map_tuple(rettup, tupmap); ReleaseTupleDesc(retdesc); /* no need to free map, we're about to return anyway */ /* Copy tuple to upper executor memory */ rettup = SPI_copytuple(rettup); } } /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end) ((*plpgsql_plugin_ptr)->func_end) (&estate, func); /* Clean up any leftover temporary memory */ plpgsql_destroy_econtext(&estate); exec_eval_cleanup(&estate); /* stmt_mcontext will be destroyed when function's main context is */ /* * Pop the error context stack */ error_context_stack = plerrcontext.previous; /* * Return the trigger's result */ return rettup; } /* ---------- * plpgsql_exec_event_trigger Called by the call handler for * event trigger execution. * ---------- */ void plpgsql_exec_event_trigger(PLpgSQL_function *func, EventTriggerData *trigdata) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int rc; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, NULL, NULL, NULL); estate.evtrigdata = trigdata; /* * Setup error traceback support for ereport() */ plerrcontext.callback = plpgsql_exec_error_callback; plerrcontext.arg = &estate; plerrcontext.previous = error_context_stack; error_context_stack = &plerrcontext; /* * Make local execution copies of all the datums */ estate.err_text = gettext_noop("during initialization of execution state"); copy_plpgsql_datums(&estate, func); /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg) ((*plpgsql_plugin_ptr)->func_beg) (&estate, func); /* * Now call the toplevel block of statements */ estate.err_text = NULL; rc = exec_toplevel_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_text = NULL; ereport(ERROR, (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT), errmsg("control reached end of trigger procedure without RETURN"))); } estate.err_text = gettext_noop("during function exit"); /* * Let the instrumentation plugin peek at this function */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end) ((*plpgsql_plugin_ptr)->func_end) (&estate, func); /* Clean up any leftover temporary memory */ plpgsql_destroy_econtext(&estate); exec_eval_cleanup(&estate); /* stmt_mcontext will be destroyed when function's main context is */ /* * Pop the error context stack */ error_context_stack = plerrcontext.previous; } /* * error context callback to let us supply a call-stack traceback */ static void plpgsql_exec_error_callback(void *arg) { PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg; int err_lineno; /* * If err_var is set, report the variable's declaration line number. * Otherwise, if err_stmt is set, report the err_stmt's line number. When * err_stmt is not set, we're in function entry/exit, or some such place * not attached to a specific line number. */ if (estate->err_var != NULL) err_lineno = estate->err_var->lineno; else if (estate->err_stmt != NULL) err_lineno = estate->err_stmt->lineno; else err_lineno = 0; if (estate->err_text != NULL) { /* * We don't expend the cycles to run gettext() on err_text unless we * actually need it. Therefore, places that set up err_text should * use gettext_noop() to ensure the strings get recorded in the * message dictionary. */ if (err_lineno > 0) { /* * translator: last %s is a phrase such as "during statement block * local variable initialization" */ errcontext("PL/pgSQL function %s line %d %s", estate->func->fn_signature, err_lineno, _(estate->err_text)); } else { /* * translator: last %s is a phrase such as "while storing call * arguments into local variables" */ errcontext("PL/pgSQL function %s %s", estate->func->fn_signature, _(estate->err_text)); } } else if (estate->err_stmt != NULL && err_lineno > 0) { /* translator: last %s is a plpgsql statement type name */ errcontext("PL/pgSQL function %s line %d at %s", estate->func->fn_signature, err_lineno, plpgsql_stmt_typename(estate->err_stmt)); } else errcontext("PL/pgSQL function %s", estate->func->fn_signature); } /* ---------- * Support function for initializing local execution variables * ---------- */ static void copy_plpgsql_datums(PLpgSQL_execstate *estate, PLpgSQL_function *func) { int ndatums = estate->ndatums; PLpgSQL_datum **indatums; PLpgSQL_datum **outdatums; char *workspace; char *ws_next; int i; /* Allocate local datum-pointer array */ estate->datums = (PLpgSQL_datum **) palloc(sizeof(PLpgSQL_datum *) * ndatums); /* * To reduce palloc overhead, we make a single palloc request for all the * space needed for locally-instantiated datums. */ workspace = palloc(func->copiable_size); ws_next = workspace; /* Fill datum-pointer array, copying datums into workspace as needed */ indatums = func->datums; outdatums = estate->datums; for (i = 0; i < ndatums; i++) { PLpgSQL_datum *indatum = indatums[i]; PLpgSQL_datum *outdatum; /* This must agree with plpgsql_finish_datums on what is copiable */ switch (indatum->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: outdatum = (PLpgSQL_datum *) ws_next; memcpy(outdatum, indatum, sizeof(PLpgSQL_var)); ws_next += MAXALIGN(sizeof(PLpgSQL_var)); break; case PLPGSQL_DTYPE_REC: outdatum = (PLpgSQL_datum *) ws_next; memcpy(outdatum, indatum, sizeof(PLpgSQL_rec)); ws_next += MAXALIGN(sizeof(PLpgSQL_rec)); break; case PLPGSQL_DTYPE_ROW: case PLPGSQL_DTYPE_RECFIELD: /* * These datum records are read-only at runtime, so no need to * copy them (well, RECFIELD contains cached data, but we'd * just as soon centralize the caching anyway). */ outdatum = indatum; break; default: elog(ERROR, "unrecognized dtype: %d", indatum->dtype); outdatum = NULL; /* keep compiler quiet */ break; } outdatums[i] = outdatum; } Assert(ws_next == workspace + func->copiable_size); } /* * If the variable has an armed "promise", compute the promised value * and assign it to the variable. * The assignment automatically disarms the promise. */ static void plpgsql_fulfill_promise(PLpgSQL_execstate *estate, PLpgSQL_var *var) { MemoryContext oldcontext; if (var->promise == PLPGSQL_PROMISE_NONE) return; /* nothing to do */ /* * This will typically be invoked in a short-lived context such as the * mcontext. We must create variable values in the estate's datum * context. This quick-and-dirty solution risks leaking some additional * cruft there, but since any one promise is honored at most once per * function call, it's probably not worth being more careful. */ oldcontext = MemoryContextSwitchTo(estate->datum_context); switch (var->promise) { case PLPGSQL_PROMISE_TG_NAME: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); assign_simple_var(estate, var, DirectFunctionCall1(namein, CStringGetDatum(estate->trigdata->tg_trigger->tgname)), false, true); break; case PLPGSQL_PROMISE_TG_WHEN: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); if (TRIGGER_FIRED_BEFORE(estate->trigdata->tg_event)) assign_text_var(estate, var, "BEFORE"); else if (TRIGGER_FIRED_AFTER(estate->trigdata->tg_event)) assign_text_var(estate, var, "AFTER"); else if (TRIGGER_FIRED_INSTEAD(estate->trigdata->tg_event)) assign_text_var(estate, var, "INSTEAD OF"); else elog(ERROR, "unrecognized trigger execution time: not BEFORE, AFTER, or INSTEAD OF"); break; case PLPGSQL_PROMISE_TG_LEVEL: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); if (TRIGGER_FIRED_FOR_ROW(estate->trigdata->tg_event)) assign_text_var(estate, var, "ROW"); else if (TRIGGER_FIRED_FOR_STATEMENT(estate->trigdata->tg_event)) assign_text_var(estate, var, "STATEMENT"); else elog(ERROR, "unrecognized trigger event type: not ROW or STATEMENT"); break; case PLPGSQL_PROMISE_TG_OP: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); if (TRIGGER_FIRED_BY_INSERT(estate->trigdata->tg_event)) assign_text_var(estate, var, "INSERT"); else if (TRIGGER_FIRED_BY_UPDATE(estate->trigdata->tg_event)) assign_text_var(estate, var, "UPDATE"); else if (TRIGGER_FIRED_BY_DELETE(estate->trigdata->tg_event)) assign_text_var(estate, var, "DELETE"); else if (TRIGGER_FIRED_BY_TRUNCATE(estate->trigdata->tg_event)) assign_text_var(estate, var, "TRUNCATE"); else elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, UPDATE, or TRUNCATE"); break; case PLPGSQL_PROMISE_TG_RELID: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); assign_simple_var(estate, var, ObjectIdGetDatum(estate->trigdata->tg_relation->rd_id), false, false); break; case PLPGSQL_PROMISE_TG_TABLE_NAME: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); assign_simple_var(estate, var, DirectFunctionCall1(namein, CStringGetDatum(RelationGetRelationName(estate->trigdata->tg_relation))), false, true); break; case PLPGSQL_PROMISE_TG_TABLE_SCHEMA: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); assign_simple_var(estate, var, DirectFunctionCall1(namein, CStringGetDatum(get_namespace_name(RelationGetNamespace(estate->trigdata->tg_relation)))), false, true); break; case PLPGSQL_PROMISE_TG_NARGS: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); assign_simple_var(estate, var, Int16GetDatum(estate->trigdata->tg_trigger->tgnargs), false, false); break; case PLPGSQL_PROMISE_TG_ARGV: if (estate->trigdata == NULL) elog(ERROR, "trigger promise is not in a trigger function"); if (estate->trigdata->tg_trigger->tgnargs > 0) { /* * For historical reasons, tg_argv[] subscripts start at zero * not one. So we can't use construct_array(). */ int nelems = estate->trigdata->tg_trigger->tgnargs; Datum *elems; int dims[1]; int lbs[1]; int i; elems = palloc(sizeof(Datum) * nelems); for (i = 0; i < nelems; i++) elems[i] = CStringGetTextDatum(estate->trigdata->tg_trigger->tgargs[i]); dims[0] = nelems; lbs[0] = 0; assign_simple_var(estate, var, PointerGetDatum(construct_md_array(elems, NULL, 1, dims, lbs, TEXTOID, -1, false, TYPALIGN_INT)), false, true); } else { assign_simple_var(estate, var, (Datum) 0, true, false); } break; case PLPGSQL_PROMISE_TG_EVENT: if (estate->evtrigdata == NULL) elog(ERROR, "event trigger promise is not in an event trigger function"); assign_text_var(estate, var, estate->evtrigdata->event); break; case PLPGSQL_PROMISE_TG_TAG: if (estate->evtrigdata == NULL) elog(ERROR, "event trigger promise is not in an event trigger function"); assign_text_var(estate, var, GetCommandTagName(estate->evtrigdata->tag)); break; default: elog(ERROR, "unrecognized promise type: %d", var->promise); } MemoryContextSwitchTo(oldcontext); } /* * Create a memory context for statement-lifespan variables, if we don't * have one already. It will be a child of stmt_mcontext_parent, which is * either the function's main context or a pushed-down outer stmt_mcontext. */ static MemoryContext get_stmt_mcontext(PLpgSQL_execstate *estate) { if (estate->stmt_mcontext == NULL) { estate->stmt_mcontext = AllocSetContextCreate(estate->stmt_mcontext_parent, "PLpgSQL per-statement data", ALLOCSET_DEFAULT_SIZES); } return estate->stmt_mcontext; } /* * Push down the current stmt_mcontext so that called statements won't use it. * This is needed by statements that have statement-lifespan data and need to * preserve it across some inner statements. The caller should eventually do * pop_stmt_mcontext(). */ static void push_stmt_mcontext(PLpgSQL_execstate *estate) { /* Should have done get_stmt_mcontext() first */ Assert(estate->stmt_mcontext != NULL); /* Assert we've not messed up the stack linkage */ Assert(MemoryContextGetParent(estate->stmt_mcontext) == estate->stmt_mcontext_parent); /* Push it down to become the parent of any nested stmt mcontext */ estate->stmt_mcontext_parent = estate->stmt_mcontext; /* And make it not available for use directly */ estate->stmt_mcontext = NULL; } /* * Undo push_stmt_mcontext(). We assume this is done just before or after * resetting the caller's stmt_mcontext; since that action will also delete * any child contexts, there's no need to explicitly delete whatever context * might currently be estate->stmt_mcontext. */ static void pop_stmt_mcontext(PLpgSQL_execstate *estate) { /* We need only pop the stack */ estate->stmt_mcontext = estate->stmt_mcontext_parent; estate->stmt_mcontext_parent = MemoryContextGetParent(estate->stmt_mcontext); } /* * Subroutine for exec_stmt_block: does any condition in the condition list * match the current exception? */ static bool exception_matches_conditions(ErrorData *edata, PLpgSQL_condition *cond) { for (; cond != NULL; cond = cond->next) { int sqlerrstate = cond->sqlerrstate; /* * OTHERS matches everything *except* query-canceled and * assert-failure. If you're foolish enough, you can match those * explicitly. */ if (sqlerrstate == 0) { if (edata->sqlerrcode != ERRCODE_QUERY_CANCELED && edata->sqlerrcode != ERRCODE_ASSERT_FAILURE) return true; } /* Exact match? */ else if (edata->sqlerrcode == sqlerrstate) return true; /* Category match? */ else if (ERRCODE_IS_CATEGORY(sqlerrstate) && ERRCODE_TO_CATEGORY(edata->sqlerrcode) == sqlerrstate) return true; } return false; } /* ---------- * exec_toplevel_block Execute the toplevel block * * This is intentionally equivalent to executing exec_stmts() with a * list consisting of the one statement. One tiny difference is that * we do not bother to save the entry value of estate->err_stmt; * that's assumed to be NULL. * ---------- */ static int exec_toplevel_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block) { int rc; estate->err_stmt = (PLpgSQL_stmt *) block; /* Let the plugin know that we are about to execute this statement */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_beg) ((*plpgsql_plugin_ptr)->stmt_beg) (estate, (PLpgSQL_stmt *) block); CHECK_FOR_INTERRUPTS(); rc = exec_stmt_block(estate, block); /* Let the plugin know that we have finished executing this statement */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_end) ((*plpgsql_plugin_ptr)->stmt_end) (estate, (PLpgSQL_stmt *) block); estate->err_stmt = NULL; return rc; } /* ---------- * exec_stmt_block Execute a block of statements * ---------- */ static int exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block) { volatile int rc = -1; int i; /* * First initialize all variables declared in this block */ estate->err_text = gettext_noop("during statement block local variable initialization"); for (i = 0; i < block->n_initvars; i++) { int n = block->initvarnos[i]; PLpgSQL_datum *datum = estate->datums[n]; /* * The set of dtypes handled here must match plpgsql_add_initdatums(). * * Note that we currently don't support promise datums within blocks, * only at a function's outermost scope, so we needn't handle those * here. * * Since RECFIELD isn't a supported case either, it's okay to cast the * PLpgSQL_datum to PLpgSQL_variable. */ estate->err_var = (PLpgSQL_variable *) datum; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) datum; /* * Free any old value, in case re-entering block, and * initialize to NULL */ assign_simple_var(estate, var, (Datum) 0, true, false); if (var->default_val == NULL) { /* * If needed, give the datatype a chance to reject * NULLs, by assigning a NULL to the variable. We * claim the value is of type UNKNOWN, not the var's * datatype, else coercion will be skipped. */ if (var->datatype->typtype == TYPTYPE_DOMAIN) exec_assign_value(estate, (PLpgSQL_datum *) var, (Datum) 0, true, UNKNOWNOID, -1); /* parser should have rejected NOT NULL */ Assert(!var->notnull); } else { exec_assign_expr(estate, (PLpgSQL_datum *) var, var->default_val); } } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; /* * Deletion of any existing object will be handled during * the assignments below, and in some cases it's more * efficient for us not to get rid of it beforehand. */ if (rec->default_val == NULL) { /* * If needed, give the datatype a chance to reject * NULLs, by assigning a NULL to the variable. */ exec_move_row(estate, (PLpgSQL_variable *) rec, NULL, NULL); /* parser should have rejected NOT NULL */ Assert(!rec->notnull); } else { exec_assign_expr(estate, (PLpgSQL_datum *) rec, rec->default_val); } } break; default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); } } estate->err_var = NULL; if (block->exceptions) { /* * Execute the statements in the block's body inside a sub-transaction */ MemoryContext oldcontext = CurrentMemoryContext; ResourceOwner oldowner = CurrentResourceOwner; ExprContext *old_eval_econtext = estate->eval_econtext; ErrorData *save_cur_error = estate->cur_error; MemoryContext stmt_mcontext; estate->err_text = gettext_noop("during statement block entry"); /* * We will need a stmt_mcontext to hold the error data if an error * occurs. It seems best to force it to exist before entering the * subtransaction, so that we reduce the risk of out-of-memory during * error recovery, and because this greatly simplifies restoring the * stmt_mcontext stack to the correct state after an error. We can * ameliorate the cost of this by allowing the called statements to * use this mcontext too; so we don't push it down here. */ stmt_mcontext = get_stmt_mcontext(estate); BeginInternalSubTransaction(NULL); /* Want to run statements inside function's memory context */ MemoryContextSwitchTo(oldcontext); PG_TRY(); { /* * We need to run the block's statements with a new eval_econtext * that belongs to the current subtransaction; if we try to use * the outer econtext then ExprContext shutdown callbacks will be * called at the wrong times. */ plpgsql_create_econtext(estate); estate->err_text = NULL; /* Run the block's statements */ rc = exec_stmts(estate, block->body); estate->err_text = gettext_noop("during statement block exit"); /* * If the block ended with RETURN, we may need to copy the return * value out of the subtransaction eval_context. We can avoid a * physical copy if the value happens to be a R/W expanded object. */ if (rc == PLPGSQL_RC_RETURN && !estate->retisset && !estate->retisnull) { int16 resTypLen; bool resTypByVal; get_typlenbyval(estate->rettype, &resTypLen, &resTypByVal); estate->retval = datumTransfer(estate->retval, resTypByVal, resTypLen); } /* Commit the inner transaction, return to outer xact context */ ReleaseCurrentSubTransaction(); MemoryContextSwitchTo(oldcontext); CurrentResourceOwner = oldowner; /* Assert that the stmt_mcontext stack is unchanged */ Assert(stmt_mcontext == estate->stmt_mcontext); /* * Revert to outer eval_econtext. (The inner one was * automatically cleaned up during subxact exit.) */ estate->eval_econtext = old_eval_econtext; } PG_CATCH(); { ErrorData *edata; ListCell *e; estate->err_text = gettext_noop("during exception cleanup"); /* Save error info in our stmt_mcontext */ MemoryContextSwitchTo(stmt_mcontext); edata = CopyErrorData(); FlushErrorState(); /* Abort the inner transaction */ RollbackAndReleaseCurrentSubTransaction(); MemoryContextSwitchTo(oldcontext); CurrentResourceOwner = oldowner; /* * Set up the stmt_mcontext stack as though we had restored our * previous state and then done push_stmt_mcontext(). The push is * needed so that statements in the exception handler won't * clobber the error data that's in our stmt_mcontext. */ estate->stmt_mcontext_parent = stmt_mcontext; estate->stmt_mcontext = NULL; /* * Now we can delete any nested stmt_mcontexts that might have * been created as children of ours. (Note: we do not immediately * release any statement-lifespan data that might have been left * behind in stmt_mcontext itself. We could attempt that by doing * a MemoryContextReset on it before collecting the error data * above, but it seems too risky to do any significant amount of * work before collecting the error.) */ MemoryContextDeleteChildren(stmt_mcontext); /* Revert to outer eval_econtext */ estate->eval_econtext = old_eval_econtext; /* * Must clean up the econtext too. However, any tuple table made * in the subxact will have been thrown away by SPI during subxact * abort, so we don't need to (and mustn't try to) free the * eval_tuptable. */ estate->eval_tuptable = NULL; exec_eval_cleanup(estate); /* Look for a matching exception handler */ foreach(e, block->exceptions->exc_list) { PLpgSQL_exception *exception = (PLpgSQL_exception *) lfirst(e); if (exception_matches_conditions(edata, exception->conditions)) { /* * Initialize the magic SQLSTATE and SQLERRM variables for * the exception block; this also frees values from any * prior use of the same exception. We needn't do this * until we have found a matching exception. */ PLpgSQL_var *state_var; PLpgSQL_var *errm_var; state_var = (PLpgSQL_var *) estate->datums[block->exceptions->sqlstate_varno]; errm_var = (PLpgSQL_var *) estate->datums[block->exceptions->sqlerrm_varno]; assign_text_var(estate, state_var, unpack_sql_state(edata->sqlerrcode)); assign_text_var(estate, errm_var, edata->message); /* * Also set up cur_error so the error data is accessible * inside the handler. */ estate->cur_error = edata; estate->err_text = NULL; rc = exec_stmts(estate, exception->action); break; } } /* * Restore previous state of cur_error, whether or not we executed * a handler. This is needed in case an error got thrown from * some inner block's exception handler. */ estate->cur_error = save_cur_error; /* If no match found, re-throw the error */ if (e == NULL) ReThrowError(edata); /* Restore stmt_mcontext stack and release the error data */ pop_stmt_mcontext(estate); MemoryContextReset(stmt_mcontext); } PG_END_TRY(); Assert(save_cur_error == estate->cur_error); } else { /* * Just execute the statements in the block's body */ estate->err_text = NULL; rc = exec_stmts(estate, block->body); } estate->err_text = NULL; /* * Handle the return code. This is intentionally different from * LOOP_RC_PROCESSING(): CONTINUE never matches a block, and EXIT matches * a block only if there is a label match. */ switch (rc) { case PLPGSQL_RC_OK: case PLPGSQL_RC_RETURN: case PLPGSQL_RC_CONTINUE: return rc; case PLPGSQL_RC_EXIT: if (estate->exitlabel == NULL) return PLPGSQL_RC_EXIT; if (block->label == NULL) return PLPGSQL_RC_EXIT; if (strcmp(block->label, estate->exitlabel) != 0) return PLPGSQL_RC_EXIT; estate->exitlabel = NULL; return PLPGSQL_RC_OK; default: elog(ERROR, "unrecognized rc: %d", rc); } return PLPGSQL_RC_OK; } /* ---------- * exec_stmts Iterate over a list of statements * as long as their return code is OK * ---------- */ static int exec_stmts(PLpgSQL_execstate *estate, List *stmts) { PLpgSQL_stmt *save_estmt = estate->err_stmt; ListCell *s; if (stmts == NIL) { /* * Ensure we do a CHECK_FOR_INTERRUPTS() even though there is no * statement. This prevents hangup in a tight loop if, for instance, * there is a LOOP construct with an empty body. */ CHECK_FOR_INTERRUPTS(); return PLPGSQL_RC_OK; } foreach(s, stmts) { PLpgSQL_stmt *stmt = (PLpgSQL_stmt *) lfirst(s); int rc; estate->err_stmt = stmt; /* Let the plugin know that we are about to execute this statement */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_beg) ((*plpgsql_plugin_ptr)->stmt_beg) (estate, stmt); CHECK_FOR_INTERRUPTS(); switch (stmt->cmd_type) { case PLPGSQL_STMT_BLOCK: rc = exec_stmt_block(estate, (PLpgSQL_stmt_block *) stmt); break; case PLPGSQL_STMT_ASSIGN: rc = exec_stmt_assign(estate, (PLpgSQL_stmt_assign *) stmt); break; case PLPGSQL_STMT_PERFORM: rc = exec_stmt_perform(estate, (PLpgSQL_stmt_perform *) stmt); break; case PLPGSQL_STMT_CALL: rc = exec_stmt_call(estate, (PLpgSQL_stmt_call *) stmt); break; case PLPGSQL_STMT_GETDIAG: rc = exec_stmt_getdiag(estate, (PLpgSQL_stmt_getdiag *) stmt); break; case PLPGSQL_STMT_IF: rc = exec_stmt_if(estate, (PLpgSQL_stmt_if *) stmt); break; case PLPGSQL_STMT_CASE: rc = exec_stmt_case(estate, (PLpgSQL_stmt_case *) stmt); break; case PLPGSQL_STMT_LOOP: rc = exec_stmt_loop(estate, (PLpgSQL_stmt_loop *) stmt); break; case PLPGSQL_STMT_WHILE: rc = exec_stmt_while(estate, (PLpgSQL_stmt_while *) stmt); break; case PLPGSQL_STMT_FORI: rc = exec_stmt_fori(estate, (PLpgSQL_stmt_fori *) stmt); break; case PLPGSQL_STMT_FORS: rc = exec_stmt_fors(estate, (PLpgSQL_stmt_fors *) stmt); break; case PLPGSQL_STMT_FORC: rc = exec_stmt_forc(estate, (PLpgSQL_stmt_forc *) stmt); break; case PLPGSQL_STMT_FOREACH_A: rc = exec_stmt_foreach_a(estate, (PLpgSQL_stmt_foreach_a *) stmt); break; case PLPGSQL_STMT_EXIT: rc = exec_stmt_exit(estate, (PLpgSQL_stmt_exit *) stmt); break; case PLPGSQL_STMT_RETURN: rc = exec_stmt_return(estate, (PLpgSQL_stmt_return *) stmt); break; case PLPGSQL_STMT_RETURN_NEXT: rc = exec_stmt_return_next(estate, (PLpgSQL_stmt_return_next *) stmt); break; case PLPGSQL_STMT_RETURN_QUERY: rc = exec_stmt_return_query(estate, (PLpgSQL_stmt_return_query *) stmt); break; case PLPGSQL_STMT_RAISE: rc = exec_stmt_raise(estate, (PLpgSQL_stmt_raise *) stmt); break; case PLPGSQL_STMT_ASSERT: rc = exec_stmt_assert(estate, (PLpgSQL_stmt_assert *) stmt); break; case PLPGSQL_STMT_EXECSQL: rc = exec_stmt_execsql(estate, (PLpgSQL_stmt_execsql *) stmt); break; case PLPGSQL_STMT_DYNEXECUTE: rc = exec_stmt_dynexecute(estate, (PLpgSQL_stmt_dynexecute *) stmt); break; case PLPGSQL_STMT_DYNFORS: rc = exec_stmt_dynfors(estate, (PLpgSQL_stmt_dynfors *) stmt); break; case PLPGSQL_STMT_OPEN: rc = exec_stmt_open(estate, (PLpgSQL_stmt_open *) stmt); break; case PLPGSQL_STMT_FETCH: rc = exec_stmt_fetch(estate, (PLpgSQL_stmt_fetch *) stmt); break; case PLPGSQL_STMT_CLOSE: rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt); break; case PLPGSQL_STMT_COMMIT: rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt); break; case PLPGSQL_STMT_ROLLBACK: rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt); break; default: /* point err_stmt to parent, since this one seems corrupt */ estate->err_stmt = save_estmt; elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type); rc = -1; /* keep compiler quiet */ } /* Let the plugin know that we have finished executing this statement */ if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_end) ((*plpgsql_plugin_ptr)->stmt_end) (estate, stmt); if (rc != PLPGSQL_RC_OK) { estate->err_stmt = save_estmt; return rc; } } /* end of loop over statements */ estate->err_stmt = save_estmt; return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_assign Evaluate an expression and * put the result into a variable. * ---------- */ static int exec_stmt_assign(PLpgSQL_execstate *estate, PLpgSQL_stmt_assign *stmt) { Assert(stmt->varno >= 0); exec_assign_expr(estate, estate->datums[stmt->varno], stmt->expr); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_perform Evaluate query and discard result (but set * FOUND depending on whether at least one row * was returned). * ---------- */ static int exec_stmt_perform(PLpgSQL_execstate *estate, PLpgSQL_stmt_perform *stmt) { PLpgSQL_expr *expr = stmt->expr; (void) exec_run_select(estate, expr, 0, NULL); exec_set_found(estate, (estate->eval_processed != 0)); exec_eval_cleanup(estate); return PLPGSQL_RC_OK; } /* * exec_stmt_call * * NOTE: this is used for both CALL and DO statements. */ static int exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt) { PLpgSQL_expr *expr = stmt->expr; LocalTransactionId before_lxid; LocalTransactionId after_lxid; ParamListInfo paramLI; SPIExecuteOptions options; int rc; /* * Make a plan if we don't have one already. */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, 0); /* * A CALL or DO can never be a simple expression. */ Assert(!expr->expr_simple_expr); /* * Also construct a DTYPE_ROW datum representing the plpgsql variables * associated with the procedure's output arguments. Then we can use * exec_move_row() to do the assignments. */ if (stmt->is_call && stmt->target == NULL) stmt->target = make_callstmt_target(estate, expr); paramLI = setup_param_list(estate, expr); before_lxid = MyProc->lxid; /* * If we have a procedure-lifespan resowner, use that to hold the refcount * for the plan. This avoids refcount leakage complaints if the called * procedure ends the current transaction. * * Also, tell SPI to allow non-atomic execution. */ memset(&options, 0, sizeof(options)); options.params = paramLI; options.read_only = estate->readonly_func; options.allow_nonatomic = true; options.owner = estate->procedure_resowner; rc = SPI_execute_plan_extended(expr->plan, &options); if (rc < 0) elog(ERROR, "SPI_execute_plan_extended failed executing query \"%s\": %s", expr->query, SPI_result_code_string(rc)); after_lxid = MyProc->lxid; if (before_lxid != after_lxid) { /* * If we are in a new transaction after the call, we need to build new * simple-expression infrastructure. */ estate->simple_eval_estate = NULL; estate->simple_eval_resowner = NULL; plpgsql_create_econtext(estate); } /* * Check result rowcount; if there's one row, assign procedure's output * values back to the appropriate variables. */ if (SPI_processed == 1) { SPITupleTable *tuptab = SPI_tuptable; if (!stmt->is_call) elog(ERROR, "DO statement returned a row"); exec_move_row(estate, stmt->target, tuptab->vals[0], tuptab->tupdesc); } else if (SPI_processed > 1) elog(ERROR, "procedure call returned more than one row"); exec_eval_cleanup(estate); SPI_freetuptable(SPI_tuptable); return PLPGSQL_RC_OK; } /* * We construct a DTYPE_ROW datum representing the plpgsql variables * associated with the procedure's output arguments. Then we can use * exec_move_row() to do the assignments. */ static PLpgSQL_variable * make_callstmt_target(PLpgSQL_execstate *estate, PLpgSQL_expr *expr) { List *plansources; CachedPlanSource *plansource; CallStmt *stmt; FuncExpr *funcexpr; HeapTuple func_tuple; Oid *argtypes; char **argnames; char *argmodes; int numargs; MemoryContext oldcontext; PLpgSQL_row *row; int nfields; int i; /* Use eval_mcontext for any cruft accumulated here */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); /* * Get the parsed CallStmt, and look up the called procedure */ plansources = SPI_plan_get_plan_sources(expr->plan); if (list_length(plansources) != 1) elog(ERROR, "query for CALL statement is not a CallStmt"); plansource = (CachedPlanSource *) linitial(plansources); if (list_length(plansource->query_list) != 1) elog(ERROR, "query for CALL statement is not a CallStmt"); stmt = (CallStmt *) linitial_node(Query, plansource->query_list)->utilityStmt; if (stmt == NULL || !IsA(stmt, CallStmt)) elog(ERROR, "query for CALL statement is not a CallStmt"); funcexpr = stmt->funcexpr; func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcexpr->funcid)); if (!HeapTupleIsValid(func_tuple)) elog(ERROR, "cache lookup failed for function %u", funcexpr->funcid); /* * Get the argument names and modes, so that we can deliver on-point error * messages when something is wrong. */ numargs = get_func_arg_info(func_tuple, &argtypes, &argnames, &argmodes); ReleaseSysCache(func_tuple); /* * Begin constructing row Datum; keep it in fn_cxt so it's adequately * long-lived. */ MemoryContextSwitchTo(estate->func->fn_cxt); row = (PLpgSQL_row *) palloc0(sizeof(PLpgSQL_row)); row->dtype = PLPGSQL_DTYPE_ROW; row->refname = "(unnamed row)"; row->lineno = -1; row->varnos = (int *) palloc(numargs * sizeof(int)); MemoryContextSwitchTo(get_eval_mcontext(estate)); /* * Examine procedure's argument list. Each output arg position should be * an unadorned plpgsql variable (Datum), which we can insert into the row * Datum. */ nfields = 0; for (i = 0; i < numargs; i++) { if (argmodes && (argmodes[i] == PROARGMODE_INOUT || argmodes[i] == PROARGMODE_OUT)) { Node *n = list_nth(stmt->outargs, nfields); if (IsA(n, Param)) { Param *param = (Param *) n; int dno; /* paramid is offset by 1 (see make_datum_param()) */ dno = param->paramid - 1; /* must check assignability now, because grammar can't */ exec_check_assignable(estate, dno); row->varnos[nfields++] = dno; } else { /* report error using parameter name, if available */ if (argnames && argnames[i] && argnames[i][0]) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("procedure parameter \"%s\" is an output parameter but corresponding argument is not writable", argnames[i]))); else ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("procedure parameter %d is an output parameter but corresponding argument is not writable", i + 1))); } } } Assert(nfields == list_length(stmt->outargs)); row->nfields = nfields; MemoryContextSwitchTo(oldcontext); return (PLpgSQL_variable *) row; } /* ---------- * exec_stmt_getdiag Put internal PG information into * specified variables. * ---------- */ static int exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt) { ListCell *lc; /* * GET STACKED DIAGNOSTICS is only valid inside an exception handler. * * Note: we trust the grammar to have disallowed the relevant item kinds * if not is_stacked, otherwise we'd dump core below. */ if (stmt->is_stacked && estate->cur_error == NULL) ereport(ERROR, (errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER), errmsg("GET STACKED DIAGNOSTICS cannot be used outside an exception handler"))); foreach(lc, stmt->diag_items) { PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc); PLpgSQL_datum *var = estate->datums[diag_item->target]; switch (diag_item->kind) { case PLPGSQL_GETDIAG_ROW_COUNT: exec_assign_value(estate, var, UInt64GetDatum(estate->eval_processed), false, INT8OID, -1); break; case PLPGSQL_GETDIAG_ROUTINE_OID: exec_assign_value(estate, var, ObjectIdGetDatum(estate->func->fn_oid), false, OIDOID, -1); break; case PLPGSQL_GETDIAG_ERROR_CONTEXT: exec_assign_c_string(estate, var, estate->cur_error->context); break; case PLPGSQL_GETDIAG_ERROR_DETAIL: exec_assign_c_string(estate, var, estate->cur_error->detail); break; case PLPGSQL_GETDIAG_ERROR_HINT: exec_assign_c_string(estate, var, estate->cur_error->hint); break; case PLPGSQL_GETDIAG_RETURNED_SQLSTATE: exec_assign_c_string(estate, var, unpack_sql_state(estate->cur_error->sqlerrcode)); break; case PLPGSQL_GETDIAG_COLUMN_NAME: exec_assign_c_string(estate, var, estate->cur_error->column_name); break; case PLPGSQL_GETDIAG_CONSTRAINT_NAME: exec_assign_c_string(estate, var, estate->cur_error->constraint_name); break; case PLPGSQL_GETDIAG_DATATYPE_NAME: exec_assign_c_string(estate, var, estate->cur_error->datatype_name); break; case PLPGSQL_GETDIAG_MESSAGE_TEXT: exec_assign_c_string(estate, var, estate->cur_error->message); break; case PLPGSQL_GETDIAG_TABLE_NAME: exec_assign_c_string(estate, var, estate->cur_error->table_name); break; case PLPGSQL_GETDIAG_SCHEMA_NAME: exec_assign_c_string(estate, var, estate->cur_error->schema_name); break; case PLPGSQL_GETDIAG_CONTEXT: { char *contextstackstr; MemoryContext oldcontext; /* Use eval_mcontext for short-lived string */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); contextstackstr = GetErrorContextStack(); MemoryContextSwitchTo(oldcontext); exec_assign_c_string(estate, var, contextstackstr); } break; default: elog(ERROR, "unrecognized diagnostic item kind: %d", diag_item->kind); } } exec_eval_cleanup(estate); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_if Evaluate a bool expression and * execute the true or false body * conditionally. * ---------- */ static int exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt) { bool value; bool isnull; ListCell *lc; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (!isnull && value) return exec_stmts(estate, stmt->then_body); foreach(lc, stmt->elsif_list) { PLpgSQL_if_elsif *elif = (PLpgSQL_if_elsif *) lfirst(lc); value = exec_eval_boolean(estate, elif->cond, &isnull); exec_eval_cleanup(estate); if (!isnull && value) return exec_stmts(estate, elif->stmts); } return exec_stmts(estate, stmt->else_body); } /*----------- * exec_stmt_case *----------- */ static int exec_stmt_case(PLpgSQL_execstate *estate, PLpgSQL_stmt_case *stmt) { PLpgSQL_var *t_var = NULL; bool isnull; ListCell *l; if (stmt->t_expr != NULL) { /* simple case */ Datum t_val; Oid t_typoid; int32 t_typmod; t_val = exec_eval_expr(estate, stmt->t_expr, &isnull, &t_typoid, &t_typmod); t_var = (PLpgSQL_var *) estate->datums[stmt->t_varno]; /* * When expected datatype is different from real, change it. Note that * what we're modifying here is an execution copy of the datum, so * this doesn't affect the originally stored function parse tree. (In * theory, if the expression datatype keeps changing during execution, * this could cause a function-lifespan memory leak. Doesn't seem * worth worrying about though.) */ if (t_var->datatype->typoid != t_typoid || t_var->datatype->atttypmod != t_typmod) t_var->datatype = plpgsql_build_datatype(t_typoid, t_typmod, estate->func->fn_input_collation, NULL); /* now we can assign to the variable */ exec_assign_value(estate, (PLpgSQL_datum *) t_var, t_val, isnull, t_typoid, t_typmod); exec_eval_cleanup(estate); } /* Now search for a successful WHEN clause */ foreach(l, stmt->case_when_list) { PLpgSQL_case_when *cwt = (PLpgSQL_case_when *) lfirst(l); bool value; value = exec_eval_boolean(estate, cwt->expr, &isnull); exec_eval_cleanup(estate); if (!isnull && value) { /* Found it */ /* We can now discard any value we had for the temp variable */ if (t_var != NULL) assign_simple_var(estate, t_var, (Datum) 0, true, false); /* Evaluate the statement(s), and we're done */ return exec_stmts(estate, cwt->stmts); } } /* We can now discard any value we had for the temp variable */ if (t_var != NULL) assign_simple_var(estate, t_var, (Datum) 0, true, false); /* SQL2003 mandates this error if there was no ELSE clause */ if (!stmt->have_else) ereport(ERROR, (errcode(ERRCODE_CASE_NOT_FOUND), errmsg("case not found"), errhint("CASE statement is missing ELSE part."))); /* Evaluate the ELSE statements, and we're done */ return exec_stmts(estate, stmt->else_stmts); } /* ---------- * exec_stmt_loop Loop over statements until * an exit occurs. * ---------- */ static int exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt) { int rc = PLPGSQL_RC_OK; for (;;) { rc = exec_stmts(estate, stmt->body); LOOP_RC_PROCESSING(stmt->label, break); } return rc; } /* ---------- * exec_stmt_while Loop over statements as long * as an expression evaluates to * true or an exit occurs. * ---------- */ static int exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt) { int rc = PLPGSQL_RC_OK; for (;;) { bool value; bool isnull; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (isnull || !value) break; rc = exec_stmts(estate, stmt->body); LOOP_RC_PROCESSING(stmt->label, break); } return rc; } /* ---------- * exec_stmt_fori Iterate an integer variable * from a lower to an upper value * incrementing or decrementing by the BY value * ---------- */ static int exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt) { PLpgSQL_var *var; Datum value; bool isnull; Oid valtype; int32 valtypmod; int32 loop_value; int32 end_value; int32 step_value; bool found = false; int rc = PLPGSQL_RC_OK; var = (PLpgSQL_var *) (estate->datums[stmt->var->dno]); /* * Get the value of the lower bound */ value = exec_eval_expr(estate, stmt->lower, &isnull, &valtype, &valtypmod); value = exec_cast_value(estate, value, &isnull, valtype, valtypmod, var->datatype->typoid, var->datatype->atttypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("lower bound of FOR loop cannot be null"))); loop_value = DatumGetInt32(value); exec_eval_cleanup(estate); /* * Get the value of the upper bound */ value = exec_eval_expr(estate, stmt->upper, &isnull, &valtype, &valtypmod); value = exec_cast_value(estate, value, &isnull, valtype, valtypmod, var->datatype->typoid, var->datatype->atttypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("upper bound of FOR loop cannot be null"))); end_value = DatumGetInt32(value); exec_eval_cleanup(estate); /* * Get the step value */ if (stmt->step) { value = exec_eval_expr(estate, stmt->step, &isnull, &valtype, &valtypmod); value = exec_cast_value(estate, value, &isnull, valtype, valtypmod, var->datatype->typoid, var->datatype->atttypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("BY value of FOR loop cannot be null"))); step_value = DatumGetInt32(value); exec_eval_cleanup(estate); if (step_value <= 0) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("BY value of FOR loop must be greater than zero"))); } else step_value = 1; /* * Now do the loop */ for (;;) { /* * Check against upper bound */ if (stmt->reverse) { if (loop_value < end_value) break; } else { if (loop_value > end_value) break; } found = true; /* looped at least once */ /* * Assign current value to loop var */ assign_simple_var(estate, var, Int32GetDatum(loop_value), false, false); /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); LOOP_RC_PROCESSING(stmt->label, break); /* * Increase/decrease loop value, unless it would overflow, in which * case exit the loop. */ if (stmt->reverse) { if (loop_value < (PG_INT32_MIN + step_value)) break; loop_value -= step_value; } else { if (loop_value > (PG_INT32_MAX - step_value)) break; loop_value += step_value; } } /* * Set the FOUND variable to indicate the result of executing the loop * (namely, whether we looped one or more times). This must be set here so * that it does not interfere with the value of the FOUND variable inside * the loop processing itself. */ exec_set_found(estate, found); return rc; } /* ---------- * exec_stmt_fors Execute a query, assign each * tuple to a record or row and * execute a group of statements * for it. * ---------- */ static int exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt) { Portal portal; int rc; /* * Open the implicit cursor for the statement using exec_run_select */ exec_run_select(estate, stmt->query, 0, &portal); /* * Execute the loop */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true); /* * Close the implicit cursor */ SPI_cursor_close(portal); return rc; } /* ---------- * exec_stmt_forc Execute a loop for each row from a cursor. * ---------- */ static int exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt) { PLpgSQL_var *curvar; MemoryContext stmt_mcontext = NULL; char *curname = NULL; PLpgSQL_expr *query; ParamListInfo paramLI; Portal portal; int rc; /* ---------- * Get the cursor variable and if it has an assigned name, check * that it's not in use currently. * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (!curvar->isnull) { MemoryContext oldcontext; /* We only need stmt_mcontext to hold the cursor name string */ stmt_mcontext = get_stmt_mcontext(estate); oldcontext = MemoryContextSwitchTo(stmt_mcontext); curname = TextDatumGetCString(curvar->value); MemoryContextSwitchTo(oldcontext); if (SPI_cursor_find(curname) != NULL) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_CURSOR), errmsg("cursor \"%s\" already in use", curname))); } /* ---------- * Open the cursor just like an OPEN command * * Note: parser should already have checked that statement supplies * args iff cursor needs them, but we check again to be safe. * ---------- */ if (stmt->argquery != NULL) { /* ---------- * OPEN CURSOR with args. We fake a SELECT ... INTO ... * statement to evaluate the args and put 'em into the * internal row. * ---------- */ PLpgSQL_stmt_execsql set_args; if (curvar->cursor_explicit_argrow < 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments given for cursor without arguments"))); memset(&set_args, 0, sizeof(set_args)); set_args.cmd_type = PLPGSQL_STMT_EXECSQL; set_args.lineno = stmt->lineno; set_args.sqlstmt = stmt->argquery; set_args.into = true; /* XXX historically this has not been STRICT */ set_args.target = (PLpgSQL_variable *) (estate->datums[curvar->cursor_explicit_argrow]); if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK) elog(ERROR, "open cursor failed during argument processing"); } else { if (curvar->cursor_explicit_argrow >= 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments required for cursor"))); } query = curvar->cursor_explicit_expr; Assert(query); if (query->plan == NULL) exec_prepare_plan(estate, query, curvar->cursor_options); /* * Set up ParamListInfo for this query */ paramLI = setup_param_list(estate, query); /* * Open the cursor (the paramlist will get copied into the portal) */ portal = SPI_cursor_open_with_paramlist(curname, query->plan, paramLI, estate->readonly_func); if (portal == NULL) elog(ERROR, "could not open cursor: %s", SPI_result_code_string(SPI_result)); /* * If cursor variable was NULL, store the generated portal name in it, * after verifying it's okay to assign to. */ if (curname == NULL) { exec_check_assignable(estate, stmt->curvar); assign_text_var(estate, curvar, portal->name); } /* * Clean up before entering exec_for_query */ exec_eval_cleanup(estate); if (stmt_mcontext) MemoryContextReset(stmt_mcontext); /* * Execute the loop. We can't prefetch because the cursor is accessible * to the user, for instance via UPDATE WHERE CURRENT OF within the loop. */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, false); /* ---------- * Close portal, and restore cursor variable if it was initially NULL. * ---------- */ SPI_cursor_close(portal); if (curname == NULL) assign_simple_var(estate, curvar, (Datum) 0, true, false); return rc; } /* ---------- * exec_stmt_foreach_a Loop over elements or slices of an array * * When looping over elements, the loop variable is the same type that the * array stores (eg: integer), when looping through slices, the loop variable * is an array of size and dimensions to match the size of the slice. * ---------- */ static int exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt) { ArrayType *arr; Oid arrtype; int32 arrtypmod; PLpgSQL_datum *loop_var; Oid loop_var_elem_type; bool found = false; int rc = PLPGSQL_RC_OK; MemoryContext stmt_mcontext; MemoryContext oldcontext; ArrayIterator array_iterator; Oid iterator_result_type; int32 iterator_result_typmod; Datum value; bool isnull; /* get the value of the array expression */ value = exec_eval_expr(estate, stmt->expr, &isnull, &arrtype, &arrtypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("FOREACH expression must not be null"))); /* * Do as much as possible of the code below in stmt_mcontext, to avoid any * leaks from called subroutines. We need a private stmt_mcontext since * we'll be calling arbitrary statement code. */ stmt_mcontext = get_stmt_mcontext(estate); push_stmt_mcontext(estate); oldcontext = MemoryContextSwitchTo(stmt_mcontext); /* check the type of the expression - must be an array */ if (!OidIsValid(get_element_type(arrtype))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("FOREACH expression must yield an array, not type %s", format_type_be(arrtype)))); /* * We must copy the array into stmt_mcontext, else it will disappear in * exec_eval_cleanup. This is annoying, but cleanup will certainly happen * while running the loop body, so we have little choice. */ arr = DatumGetArrayTypePCopy(value); /* Clean up any leftover temporary memory */ exec_eval_cleanup(estate); /* Slice dimension must be less than or equal to array dimension */ if (stmt->slice < 0 || stmt->slice > ARR_NDIM(arr)) ereport(ERROR, (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR), errmsg("slice dimension (%d) is out of the valid range 0..%d", stmt->slice, ARR_NDIM(arr)))); /* Set up the loop variable and see if it is of an array type */ loop_var = estate->datums[stmt->varno]; if (loop_var->dtype == PLPGSQL_DTYPE_REC || loop_var->dtype == PLPGSQL_DTYPE_ROW) { /* * Record/row variable is certainly not of array type, and might not * be initialized at all yet, so don't try to get its type */ loop_var_elem_type = InvalidOid; } else loop_var_elem_type = get_element_type(plpgsql_exec_get_datum_type(estate, loop_var)); /* * Sanity-check the loop variable type. We don't try very hard here, and * should not be too picky since it's possible that exec_assign_value can * coerce values of different types. But it seems worthwhile to complain * if the array-ness of the loop variable is not right. */ if (stmt->slice > 0 && loop_var_elem_type == InvalidOid) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("FOREACH ... SLICE loop variable must be of an array type"))); if (stmt->slice == 0 && loop_var_elem_type != InvalidOid) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("FOREACH loop variable must not be of an array type"))); /* Create an iterator to step through the array */ array_iterator = array_create_iterator(arr, stmt->slice, NULL); /* Identify iterator result type */ if (stmt->slice > 0) { /* When slicing, nominal type of result is same as array type */ iterator_result_type = arrtype; iterator_result_typmod = arrtypmod; } else { /* Without slicing, results are individual array elements */ iterator_result_type = ARR_ELEMTYPE(arr); iterator_result_typmod = arrtypmod; } /* Iterate over the array elements or slices */ while (array_iterate(array_iterator, &value, &isnull)) { found = true; /* looped at least once */ /* exec_assign_value and exec_stmts must run in the main context */ MemoryContextSwitchTo(oldcontext); /* Assign current element/slice to the loop variable */ exec_assign_value(estate, loop_var, value, isnull, iterator_result_type, iterator_result_typmod); /* In slice case, value is temporary; must free it to avoid leakage */ if (stmt->slice > 0) pfree(DatumGetPointer(value)); /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); LOOP_RC_PROCESSING(stmt->label, break); MemoryContextSwitchTo(stmt_mcontext); } /* Restore memory context state */ MemoryContextSwitchTo(oldcontext); pop_stmt_mcontext(estate); /* Release temporary memory, including the array value */ MemoryContextReset(stmt_mcontext); /* * Set the FOUND variable to indicate the result of executing the loop * (namely, whether we looped one or more times). This must be set here so * that it does not interfere with the value of the FOUND variable inside * the loop processing itself. */ exec_set_found(estate, found); return rc; } /* ---------- * exec_stmt_exit Implements EXIT and CONTINUE * * This begins the process of exiting / restarting a loop. * ---------- */ static int exec_stmt_exit(PLpgSQL_execstate *estate, PLpgSQL_stmt_exit *stmt) { /* * If the exit / continue has a condition, evaluate it */ if (stmt->cond != NULL) { bool value; bool isnull; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (isnull || value == false) return PLPGSQL_RC_OK; } estate->exitlabel = stmt->label; if (stmt->is_exit) return PLPGSQL_RC_EXIT; else return PLPGSQL_RC_CONTINUE; } /* ---------- * exec_stmt_return Evaluate an expression and start * returning from the function. * * Note: The result may be in the eval_mcontext. Therefore, we must not * do exec_eval_cleanup while unwinding the control stack. * ---------- */ static int exec_stmt_return(PLpgSQL_execstate *estate, PLpgSQL_stmt_return *stmt) { /* * If processing a set-returning PL/pgSQL function, the final RETURN * indicates that the function is finished producing tuples. The rest of * the work will be done at the top level. */ if (estate->retisset) return PLPGSQL_RC_RETURN; /* initialize for null result */ estate->retval = (Datum) 0; estate->retisnull = true; estate->rettype = InvalidOid; /* * Special case path when the RETURN expression is a simple variable * reference; in particular, this path is always taken in functions with * one or more OUT parameters. * * This special case is especially efficient for returning variables that * have R/W expanded values: we can put the R/W pointer directly into * estate->retval, leading to transferring the value to the caller's * context cheaply. If we went through exec_eval_expr we'd end up with a * R/O pointer. It's okay to skip MakeExpandedObjectReadOnly here since * we know we won't need the variable's value within the function anymore. */ if (stmt->retvarno >= 0) { PLpgSQL_datum *retvar = estate->datums[stmt->retvarno]; switch (retvar->dtype) { case PLPGSQL_DTYPE_PROMISE: /* fulfill promise if needed, then handle like regular var */ plpgsql_fulfill_promise(estate, (PLpgSQL_var *) retvar); /* FALL THRU */ case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) retvar; estate->retval = var->value; estate->retisnull = var->isnull; estate->rettype = var->datatype->typoid; /* * A PLpgSQL_var could not be of composite type, so * conversion must fail if retistuple. We throw a custom * error mainly for consistency with historical behavior. * For the same reason, we don't throw error if the result * is NULL. (Note that plpgsql_exec_trigger assumes that * any non-null result has been verified to be composite.) */ if (estate->retistuple && !estate->retisnull) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot return non-composite value from function returning composite type"))); } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar; /* If record is empty, we return NULL not a row of nulls */ if (rec->erh && !ExpandedRecordIsEmpty(rec->erh)) { estate->retval = ExpandedRecordGetDatum(rec->erh); estate->retisnull = false; estate->rettype = rec->rectypeid; } } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; int32 rettypmod; /* We get here if there are multiple OUT parameters */ exec_eval_datum(estate, (PLpgSQL_datum *) row, &estate->rettype, &rettypmod, &estate->retval, &estate->retisnull); } break; default: elog(ERROR, "unrecognized dtype: %d", retvar->dtype); } return PLPGSQL_RC_RETURN; } if (stmt->expr != NULL) { int32 rettypmod; estate->retval = exec_eval_expr(estate, stmt->expr, &(estate->retisnull), &(estate->rettype), &rettypmod); /* * As in the DTYPE_VAR case above, throw a custom error if a non-null, * non-composite value is returned in a function returning tuple. */ if (estate->retistuple && !estate->retisnull && !type_is_rowtype(estate->rettype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot return non-composite value from function returning composite type"))); return PLPGSQL_RC_RETURN; } /* * Special hack for function returning VOID: instead of NULL, return a * non-null VOID value. This is of dubious importance but is kept for * backwards compatibility. We don't do it for procedures, though. */ if (estate->fn_rettype == VOIDOID && estate->func->fn_prokind != PROKIND_PROCEDURE) { estate->retval = (Datum) 0; estate->retisnull = false; estate->rettype = VOIDOID; } return PLPGSQL_RC_RETURN; } /* ---------- * exec_stmt_return_next Evaluate an expression and add it to the * list of tuples returned by the current * SRF. * ---------- */ static int exec_stmt_return_next(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_next *stmt) { TupleDesc tupdesc; int natts; HeapTuple tuple; MemoryContext oldcontext; if (!estate->retisset) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot use RETURN NEXT in a non-SETOF function"))); if (estate->tuple_store == NULL) exec_init_tuple_store(estate); /* tuple_store_desc will be filled by exec_init_tuple_store */ tupdesc = estate->tuple_store_desc; natts = tupdesc->natts; /* * Special case path when the RETURN NEXT expression is a simple variable * reference; in particular, this path is always taken in functions with * one or more OUT parameters. * * Unlike exec_stmt_return, there's no special win here for R/W expanded * values, since they'll have to get flattened to go into the tuplestore. * Indeed, we'd better make them R/O to avoid any risk of the casting step * changing them in-place. */ if (stmt->retvarno >= 0) { PLpgSQL_datum *retvar = estate->datums[stmt->retvarno]; switch (retvar->dtype) { case PLPGSQL_DTYPE_PROMISE: /* fulfill promise if needed, then handle like regular var */ plpgsql_fulfill_promise(estate, (PLpgSQL_var *) retvar); /* FALL THRU */ case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) retvar; Datum retval = var->value; bool isNull = var->isnull; Form_pg_attribute attr = TupleDescAttr(tupdesc, 0); if (natts != 1) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong result type supplied in RETURN NEXT"))); /* let's be very paranoid about the cast step */ retval = MakeExpandedObjectReadOnly(retval, isNull, var->datatype->typlen); /* coerce type if needed */ retval = exec_cast_value(estate, retval, &isNull, var->datatype->typoid, var->datatype->atttypmod, attr->atttypid, attr->atttypmod); tuplestore_putvalues(estate->tuple_store, tupdesc, &retval, &isNull); } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar; TupleDesc rec_tupdesc; TupleConversionMap *tupmap; /* If rec is null, try to convert it to a row of nulls */ if (rec->erh == NULL) instantiate_empty_record_variable(estate, rec); if (ExpandedRecordIsEmpty(rec->erh)) deconstruct_expanded_record(rec->erh); /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); rec_tupdesc = expanded_record_get_tupdesc(rec->erh); tupmap = convert_tuples_by_position(rec_tupdesc, tupdesc, gettext_noop("wrong record type supplied in RETURN NEXT")); tuple = expanded_record_get_tuple(rec->erh); if (tupmap) tuple = execute_attr_map_tuple(tuple, tupmap); tuplestore_puttuple(estate->tuple_store, tuple); MemoryContextSwitchTo(oldcontext); } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; /* We get here if there are multiple OUT parameters */ /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); tuple = make_tuple_from_row(estate, row, tupdesc); if (tuple == NULL) /* should not happen */ ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong record type supplied in RETURN NEXT"))); tuplestore_puttuple(estate->tuple_store, tuple); MemoryContextSwitchTo(oldcontext); } break; default: elog(ERROR, "unrecognized dtype: %d", retvar->dtype); break; } } else if (stmt->expr) { Datum retval; bool isNull; Oid rettype; int32 rettypmod; retval = exec_eval_expr(estate, stmt->expr, &isNull, &rettype, &rettypmod); if (estate->retistuple) { /* Expression should be of RECORD or composite type */ if (!isNull) { HeapTupleData tmptup; TupleDesc retvaldesc; TupleConversionMap *tupmap; if (!type_is_rowtype(rettype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot return non-composite value from function returning composite type"))); /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); retvaldesc = deconstruct_composite_datum(retval, &tmptup); tuple = &tmptup; tupmap = convert_tuples_by_position(retvaldesc, tupdesc, gettext_noop("returned record type does not match expected record type")); if (tupmap) tuple = execute_attr_map_tuple(tuple, tupmap); tuplestore_puttuple(estate->tuple_store, tuple); ReleaseTupleDesc(retvaldesc); MemoryContextSwitchTo(oldcontext); } else { /* Composite NULL --- store a row of nulls */ Datum *nulldatums; bool *nullflags; nulldatums = (Datum *) eval_mcontext_alloc0(estate, natts * sizeof(Datum)); nullflags = (bool *) eval_mcontext_alloc(estate, natts * sizeof(bool)); memset(nullflags, true, natts * sizeof(bool)); tuplestore_putvalues(estate->tuple_store, tupdesc, nulldatums, nullflags); } } else { Form_pg_attribute attr = TupleDescAttr(tupdesc, 0); /* Simple scalar result */ if (natts != 1) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong result type supplied in RETURN NEXT"))); /* coerce type if needed */ retval = exec_cast_value(estate, retval, &isNull, rettype, rettypmod, attr->atttypid, attr->atttypmod); tuplestore_putvalues(estate->tuple_store, tupdesc, &retval, &isNull); } } else { ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RETURN NEXT must have a parameter"))); } exec_eval_cleanup(estate); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_return_query Evaluate a query and add it to the * list of tuples returned by the current * SRF. * ---------- */ static int exec_stmt_return_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_query *stmt) { int64 tcount; DestReceiver *treceiver; int rc; uint64 processed; MemoryContext stmt_mcontext = get_stmt_mcontext(estate); MemoryContext oldcontext; if (!estate->retisset) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot use RETURN QUERY in a non-SETOF function"))); if (estate->tuple_store == NULL) exec_init_tuple_store(estate); /* There might be some tuples in the tuplestore already */ tcount = tuplestore_tuple_count(estate->tuple_store); /* * Set up DestReceiver to transfer results directly to tuplestore, * converting rowtype if necessary. DestReceiver lives in mcontext. */ oldcontext = MemoryContextSwitchTo(stmt_mcontext); treceiver = CreateDestReceiver(DestTuplestore); SetTuplestoreDestReceiverParams(treceiver, estate->tuple_store, estate->tuple_store_cxt, false, estate->tuple_store_desc, gettext_noop("structure of query does not match function result type")); MemoryContextSwitchTo(oldcontext); if (stmt->query != NULL) { /* static query */ PLpgSQL_expr *expr = stmt->query; ParamListInfo paramLI; SPIExecuteOptions options; /* * On the first call for this expression generate the plan. */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK); /* * Set up ParamListInfo to pass to executor */ paramLI = setup_param_list(estate, expr); /* * Execute the query */ memset(&options, 0, sizeof(options)); options.params = paramLI; options.read_only = estate->readonly_func; options.must_return_tuples = true; options.dest = treceiver; rc = SPI_execute_plan_extended(expr->plan, &options); if (rc < 0) elog(ERROR, "SPI_execute_plan_extended failed executing query \"%s\": %s", expr->query, SPI_result_code_string(rc)); } else { /* RETURN QUERY EXECUTE */ Datum query; bool isnull; Oid restype; int32 restypmod; char *querystr; SPIExecuteOptions options; /* * Evaluate the string expression after the EXECUTE keyword. Its * result is the querystring we have to execute. */ Assert(stmt->dynquery != NULL); query = exec_eval_expr(estate, stmt->dynquery, &isnull, &restype, &restypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(estate, query, restype); /* copy it into the stmt_mcontext before we clean up */ querystr = MemoryContextStrdup(stmt_mcontext, querystr); exec_eval_cleanup(estate); /* Execute query, passing params if necessary */ memset(&options, 0, sizeof(options)); options.params = exec_eval_using_params(estate, stmt->params); options.read_only = estate->readonly_func; options.must_return_tuples = true; options.dest = treceiver; rc = SPI_execute_extended(querystr, &options); if (rc < 0) elog(ERROR, "SPI_execute_extended failed executing query \"%s\": %s", querystr, SPI_result_code_string(rc)); } /* Clean up */ treceiver->rDestroy(treceiver); exec_eval_cleanup(estate); MemoryContextReset(stmt_mcontext); /* Count how many tuples we got */ processed = tuplestore_tuple_count(estate->tuple_store) - tcount; estate->eval_processed = processed; exec_set_found(estate, processed != 0); return PLPGSQL_RC_OK; } static void exec_init_tuple_store(PLpgSQL_execstate *estate) { ReturnSetInfo *rsi = estate->rsi; MemoryContext oldcxt; ResourceOwner oldowner; /* * Check caller can handle a set result in the way we want */ if (!rsi || !IsA(rsi, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsi->allowedModes & SFRM_Materialize) || rsi->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); /* * Switch to the right memory context and resource owner for storing the * tuplestore for return set. If we're within a subtransaction opened for * an exception-block, for example, we must still create the tuplestore in * the resource owner that was active when this function was entered, and * not in the subtransaction resource owner. */ oldcxt = MemoryContextSwitchTo(estate->tuple_store_cxt); oldowner = CurrentResourceOwner; CurrentResourceOwner = estate->tuple_store_owner; estate->tuple_store = tuplestore_begin_heap(rsi->allowedModes & SFRM_Materialize_Random, false, work_mem); CurrentResourceOwner = oldowner; MemoryContextSwitchTo(oldcxt); estate->tuple_store_desc = rsi->expectedDesc; } #define SET_RAISE_OPTION_TEXT(opt, name) \ do { \ if (opt) \ ereport(ERROR, \ (errcode(ERRCODE_SYNTAX_ERROR), \ errmsg("RAISE option already specified: %s", \ name))); \ opt = MemoryContextStrdup(stmt_mcontext, extval); \ } while (0) /* ---------- * exec_stmt_raise Build a message and throw it with elog() * ---------- */ static int exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt) { int err_code = 0; char *condname = NULL; char *err_message = NULL; char *err_detail = NULL; char *err_hint = NULL; char *err_column = NULL; char *err_constraint = NULL; char *err_datatype = NULL; char *err_table = NULL; char *err_schema = NULL; MemoryContext stmt_mcontext; ListCell *lc; /* RAISE with no parameters: re-throw current exception */ if (stmt->condname == NULL && stmt->message == NULL && stmt->options == NIL) { if (estate->cur_error != NULL) ReThrowError(estate->cur_error); /* oops, we're not inside a handler */ ereport(ERROR, (errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER), errmsg("RAISE without parameters cannot be used outside an exception handler"))); } /* We'll need to accumulate the various strings in stmt_mcontext */ stmt_mcontext = get_stmt_mcontext(estate); if (stmt->condname) { err_code = plpgsql_recognize_err_condition(stmt->condname, true); condname = MemoryContextStrdup(stmt_mcontext, stmt->condname); } if (stmt->message) { StringInfoData ds; ListCell *current_param; char *cp; MemoryContext oldcontext; /* build string in stmt_mcontext */ oldcontext = MemoryContextSwitchTo(stmt_mcontext); initStringInfo(&ds); MemoryContextSwitchTo(oldcontext); current_param = list_head(stmt->params); for (cp = stmt->message; *cp; cp++) { /* * Occurrences of a single % are replaced by the next parameter's * external representation. Double %'s are converted to one %. */ if (cp[0] == '%') { Oid paramtypeid; int32 paramtypmod; Datum paramvalue; bool paramisnull; char *extval; if (cp[1] == '%') { appendStringInfoChar(&ds, '%'); cp++; continue; } /* should have been checked at compile time */ if (current_param == NULL) elog(ERROR, "unexpected RAISE parameter list length"); paramvalue = exec_eval_expr(estate, (PLpgSQL_expr *) lfirst(current_param), ¶misnull, ¶mtypeid, ¶mtypmod); if (paramisnull) extval = ""; else extval = convert_value_to_string(estate, paramvalue, paramtypeid); appendStringInfoString(&ds, extval); current_param = lnext(stmt->params, current_param); exec_eval_cleanup(estate); } else appendStringInfoChar(&ds, cp[0]); } /* should have been checked at compile time */ if (current_param != NULL) elog(ERROR, "unexpected RAISE parameter list length"); err_message = ds.data; } foreach(lc, stmt->options) { PLpgSQL_raise_option *opt = (PLpgSQL_raise_option *) lfirst(lc); Datum optionvalue; bool optionisnull; Oid optiontypeid; int32 optiontypmod; char *extval; optionvalue = exec_eval_expr(estate, opt->expr, &optionisnull, &optiontypeid, &optiontypmod); if (optionisnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("RAISE statement option cannot be null"))); extval = convert_value_to_string(estate, optionvalue, optiontypeid); switch (opt->opt_type) { case PLPGSQL_RAISEOPTION_ERRCODE: if (err_code) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE option already specified: %s", "ERRCODE"))); err_code = plpgsql_recognize_err_condition(extval, true); condname = MemoryContextStrdup(stmt_mcontext, extval); break; case PLPGSQL_RAISEOPTION_MESSAGE: SET_RAISE_OPTION_TEXT(err_message, "MESSAGE"); break; case PLPGSQL_RAISEOPTION_DETAIL: SET_RAISE_OPTION_TEXT(err_detail, "DETAIL"); break; case PLPGSQL_RAISEOPTION_HINT: SET_RAISE_OPTION_TEXT(err_hint, "HINT"); break; case PLPGSQL_RAISEOPTION_COLUMN: SET_RAISE_OPTION_TEXT(err_column, "COLUMN"); break; case PLPGSQL_RAISEOPTION_CONSTRAINT: SET_RAISE_OPTION_TEXT(err_constraint, "CONSTRAINT"); break; case PLPGSQL_RAISEOPTION_DATATYPE: SET_RAISE_OPTION_TEXT(err_datatype, "DATATYPE"); break; case PLPGSQL_RAISEOPTION_TABLE: SET_RAISE_OPTION_TEXT(err_table, "TABLE"); break; case PLPGSQL_RAISEOPTION_SCHEMA: SET_RAISE_OPTION_TEXT(err_schema, "SCHEMA"); break; default: elog(ERROR, "unrecognized raise option: %d", opt->opt_type); } exec_eval_cleanup(estate); } /* Default code if nothing specified */ if (err_code == 0 && stmt->elog_level >= ERROR) err_code = ERRCODE_RAISE_EXCEPTION; /* Default error message if nothing specified */ if (err_message == NULL) { if (condname) { err_message = condname; condname = NULL; } else err_message = MemoryContextStrdup(stmt_mcontext, unpack_sql_state(err_code)); } /* * Throw the error (may or may not come back) */ ereport(stmt->elog_level, (err_code ? errcode(err_code) : 0, errmsg_internal("%s", err_message), (err_detail != NULL) ? errdetail_internal("%s", err_detail) : 0, (err_hint != NULL) ? errhint("%s", err_hint) : 0, (err_column != NULL) ? err_generic_string(PG_DIAG_COLUMN_NAME, err_column) : 0, (err_constraint != NULL) ? err_generic_string(PG_DIAG_CONSTRAINT_NAME, err_constraint) : 0, (err_datatype != NULL) ? err_generic_string(PG_DIAG_DATATYPE_NAME, err_datatype) : 0, (err_table != NULL) ? err_generic_string(PG_DIAG_TABLE_NAME, err_table) : 0, (err_schema != NULL) ? err_generic_string(PG_DIAG_SCHEMA_NAME, err_schema) : 0)); /* Clean up transient strings */ MemoryContextReset(stmt_mcontext); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_assert Assert statement * ---------- */ static int exec_stmt_assert(PLpgSQL_execstate *estate, PLpgSQL_stmt_assert *stmt) { bool value; bool isnull; /* do nothing when asserts are not enabled */ if (!plpgsql_check_asserts) return PLPGSQL_RC_OK; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (isnull || !value) { char *message = NULL; if (stmt->message != NULL) { Datum val; Oid typeid; int32 typmod; val = exec_eval_expr(estate, stmt->message, &isnull, &typeid, &typmod); if (!isnull) message = convert_value_to_string(estate, val, typeid); /* we mustn't do exec_eval_cleanup here */ } ereport(ERROR, (errcode(ERRCODE_ASSERT_FAILURE), message ? errmsg_internal("%s", message) : errmsg("assertion failed"))); } return PLPGSQL_RC_OK; } /* ---------- * Initialize a mostly empty execution state * ---------- */ static void plpgsql_estate_setup(PLpgSQL_execstate *estate, PLpgSQL_function *func, ReturnSetInfo *rsi, EState *simple_eval_estate, ResourceOwner simple_eval_resowner) { HASHCTL ctl; /* this link will be restored at exit from plpgsql_call_handler */ func->cur_estate = estate; estate->func = func; estate->trigdata = NULL; estate->evtrigdata = NULL; estate->retval = (Datum) 0; estate->retisnull = true; estate->rettype = InvalidOid; estate->fn_rettype = func->fn_rettype; estate->retistuple = func->fn_retistuple; estate->retisset = func->fn_retset; estate->readonly_func = func->fn_readonly; estate->atomic = true; estate->exitlabel = NULL; estate->cur_error = NULL; estate->tuple_store = NULL; estate->tuple_store_desc = NULL; if (rsi) { estate->tuple_store_cxt = rsi->econtext->ecxt_per_query_memory; estate->tuple_store_owner = CurrentResourceOwner; } else { estate->tuple_store_cxt = NULL; estate->tuple_store_owner = NULL; } estate->rsi = rsi; estate->found_varno = func->found_varno; estate->ndatums = func->ndatums; estate->datums = NULL; /* the datums array will be filled by copy_plpgsql_datums() */ estate->datum_context = CurrentMemoryContext; /* initialize our ParamListInfo with appropriate hook functions */ estate->paramLI = makeParamList(0); estate->paramLI->paramFetch = plpgsql_param_fetch; estate->paramLI->paramFetchArg = (void *) estate; estate->paramLI->paramCompile = plpgsql_param_compile; estate->paramLI->paramCompileArg = NULL; /* not needed */ estate->paramLI->parserSetup = (ParserSetupHook) plpgsql_parser_setup; estate->paramLI->parserSetupArg = NULL; /* filled during use */ estate->paramLI->numParams = estate->ndatums; /* Create the session-wide cast-expression hash if we didn't already */ if (cast_expr_hash == NULL) { ctl.keysize = sizeof(plpgsql_CastHashKey); ctl.entrysize = sizeof(plpgsql_CastExprHashEntry); cast_expr_hash = hash_create("PLpgSQL cast expressions", 16, /* start small and extend */ &ctl, HASH_ELEM | HASH_BLOBS); } /* set up for use of appropriate simple-expression EState and cast hash */ if (simple_eval_estate) { estate->simple_eval_estate = simple_eval_estate; /* Private cast hash just lives in function's main context */ ctl.keysize = sizeof(plpgsql_CastHashKey); ctl.entrysize = sizeof(plpgsql_CastHashEntry); ctl.hcxt = CurrentMemoryContext; estate->cast_hash = hash_create("PLpgSQL private cast cache", 16, /* start small and extend */ &ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); } else { estate->simple_eval_estate = shared_simple_eval_estate; /* Create the session-wide cast-info hash table if we didn't already */ if (shared_cast_hash == NULL) { ctl.keysize = sizeof(plpgsql_CastHashKey); ctl.entrysize = sizeof(plpgsql_CastHashEntry); shared_cast_hash = hash_create("PLpgSQL cast cache", 16, /* start small and extend */ &ctl, HASH_ELEM | HASH_BLOBS); } estate->cast_hash = shared_cast_hash; } /* likewise for the simple-expression resource owner */ if (simple_eval_resowner) estate->simple_eval_resowner = simple_eval_resowner; else estate->simple_eval_resowner = shared_simple_eval_resowner; /* if there's a procedure resowner, it'll be filled in later */ estate->procedure_resowner = NULL; /* * We start with no stmt_mcontext; one will be created only if needed. * That context will be a direct child of the function's main execution * context. Additional stmt_mcontexts might be created as children of it. */ estate->stmt_mcontext = NULL; estate->stmt_mcontext_parent = CurrentMemoryContext; estate->eval_tuptable = NULL; estate->eval_processed = 0; estate->eval_econtext = NULL; estate->err_stmt = NULL; estate->err_var = NULL; estate->err_text = NULL; estate->plugin_info = NULL; /* * Create an EState and ExprContext for evaluation of simple expressions. */ plpgsql_create_econtext(estate); /* * Let the plugin, if any, see this function before we initialize local * PL/pgSQL variables. Note that we also give the plugin a few function * pointers, so it can call back into PL/pgSQL for doing things like * variable assignments and stack traces. */ if (*plpgsql_plugin_ptr) { (*plpgsql_plugin_ptr)->error_callback = plpgsql_exec_error_callback; (*plpgsql_plugin_ptr)->assign_expr = exec_assign_expr; (*plpgsql_plugin_ptr)->assign_value = exec_assign_value; (*plpgsql_plugin_ptr)->eval_datum = exec_eval_datum; (*plpgsql_plugin_ptr)->cast_value = exec_cast_value; if ((*plpgsql_plugin_ptr)->func_setup) ((*plpgsql_plugin_ptr)->func_setup) (estate, func); } } /* ---------- * Release temporary memory used by expression/subselect evaluation * * NB: the result of the evaluation is no longer valid after this is done, * unless it is a pass-by-value datatype. * ---------- */ static void exec_eval_cleanup(PLpgSQL_execstate *estate) { /* Clear result of a full SPI_execute */ if (estate->eval_tuptable != NULL) SPI_freetuptable(estate->eval_tuptable); estate->eval_tuptable = NULL; /* * Clear result of exec_eval_simple_expr (but keep the econtext). This * also clears any short-lived allocations done via get_eval_mcontext. */ if (estate->eval_econtext != NULL) ResetExprContext(estate->eval_econtext); } /* ---------- * Generate a prepared plan * * CAUTION: it is possible for this function to throw an error after it has * built a SPIPlan and saved it in expr->plan. Therefore, be wary of doing * additional things contingent on expr->plan being NULL. That is, given * code like * * if (query->plan == NULL) * { * // okay to put setup code here * exec_prepare_plan(estate, query, ...); * // NOT okay to put more logic here * } * * extra steps at the end are unsafe because they will not be executed when * re-executing the calling statement, if exec_prepare_plan failed the first * time. This is annoyingly error-prone, but the alternatives are worse. * ---------- */ static void exec_prepare_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, int cursorOptions) { SPIPlanPtr plan; SPIPrepareOptions options; /* * The grammar can't conveniently set expr->func while building the parse * tree, so make sure it's set before parser hooks need it. */ expr->func = estate->func; /* * Generate and save the plan */ memset(&options, 0, sizeof(options)); options.parserSetup = (ParserSetupHook) plpgsql_parser_setup; options.parserSetupArg = (void *) expr; options.parseMode = expr->parseMode; options.cursorOptions = cursorOptions; plan = SPI_prepare_extended(expr->query, &options); if (plan == NULL) elog(ERROR, "SPI_prepare_extended failed for \"%s\": %s", expr->query, SPI_result_code_string(SPI_result)); SPI_keepplan(plan); expr->plan = plan; /* Check to see if it's a simple expression */ exec_simple_check_plan(estate, expr); } /* ---------- * exec_stmt_execsql Execute an SQL statement (possibly with INTO). * * Note: some callers rely on this not touching stmt_mcontext. If it ever * needs to use that, fix those callers to push/pop stmt_mcontext. * ---------- */ static int exec_stmt_execsql(PLpgSQL_execstate *estate, PLpgSQL_stmt_execsql *stmt) { ParamListInfo paramLI; long tcount; int rc; PLpgSQL_expr *expr = stmt->sqlstmt; int too_many_rows_level = 0; if (plpgsql_extra_errors & PLPGSQL_XCHECK_TOOMANYROWS) too_many_rows_level = ERROR; else if (plpgsql_extra_warnings & PLPGSQL_XCHECK_TOOMANYROWS) too_many_rows_level = WARNING; /* * On the first call for this statement generate the plan, and detect * whether the statement is INSERT/UPDATE/DELETE/MERGE */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK); if (!stmt->mod_stmt_set) { ListCell *l; stmt->mod_stmt = false; foreach(l, SPI_plan_get_plan_sources(expr->plan)) { CachedPlanSource *plansource = (CachedPlanSource *) lfirst(l); /* * We could look at the raw_parse_tree, but it seems simpler to * check the command tag. Note we should *not* look at the Query * tree(s), since those are the result of rewriting and could have * been transmogrified into something else entirely. */ if (plansource->commandTag == CMDTAG_INSERT || plansource->commandTag == CMDTAG_UPDATE || plansource->commandTag == CMDTAG_DELETE || plansource->commandTag == CMDTAG_MERGE) { stmt->mod_stmt = true; break; } } stmt->mod_stmt_set = true; } /* * Set up ParamListInfo to pass to executor */ paramLI = setup_param_list(estate, expr); /* * If we have INTO, then we only need one row back ... but if we have INTO * STRICT or extra check too_many_rows, ask for two rows, so that we can * verify the statement returns only one. INSERT/UPDATE/DELETE are always * treated strictly. Without INTO, just run the statement to completion * (tcount = 0). * * We could just ask for two rows always when using INTO, but there are * some cases where demanding the extra row costs significant time, eg by * forcing completion of a sequential scan. So don't do it unless we need * to enforce strictness. */ if (stmt->into) { if (stmt->strict || stmt->mod_stmt || too_many_rows_level) tcount = 2; else tcount = 1; } else tcount = 0; /* * Execute the plan */ rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI, estate->readonly_func, tcount); /* * Check for error, and set FOUND if appropriate (for historical reasons * we set FOUND only for certain query types). Also Assert that we * identified the statement type the same as SPI did. */ switch (rc) { case SPI_OK_SELECT: Assert(!stmt->mod_stmt); exec_set_found(estate, (SPI_processed != 0)); break; case SPI_OK_INSERT: case SPI_OK_UPDATE: case SPI_OK_DELETE: case SPI_OK_INSERT_RETURNING: case SPI_OK_UPDATE_RETURNING: case SPI_OK_DELETE_RETURNING: case SPI_OK_MERGE: Assert(stmt->mod_stmt); exec_set_found(estate, (SPI_processed != 0)); break; case SPI_OK_SELINTO: case SPI_OK_UTILITY: Assert(!stmt->mod_stmt); break; case SPI_OK_REWRITTEN: /* * The command was rewritten into another kind of command. It's * not clear what FOUND would mean in that case (and SPI doesn't * return the row count either), so just set it to false. Note * that we can't assert anything about mod_stmt here. */ exec_set_found(estate, false); break; /* Some SPI errors deserve specific error messages */ case SPI_ERROR_COPY: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot COPY to/from client in PL/pgSQL"))); break; case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("unsupported transaction command in PL/pgSQL"))); break; default: elog(ERROR, "SPI_execute_plan_with_paramlist failed executing query \"%s\": %s", expr->query, SPI_result_code_string(rc)); break; } /* All variants should save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; /* Process INTO if present */ if (stmt->into) { SPITupleTable *tuptab = SPI_tuptable; uint64 n = SPI_processed; PLpgSQL_variable *target; /* If the statement did not return a tuple table, complain */ if (tuptab == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("INTO used with a command that cannot return data"))); /* Fetch target's datum entry */ target = (PLpgSQL_variable *) estate->datums[stmt->target->dno]; /* * If SELECT ... INTO specified STRICT, and the query didn't find * exactly one row, throw an error. If STRICT was not specified, then * allow the query to find any number of rows. */ if (n == 0) { if (stmt->strict) { char *errdetail; if (estate->func->print_strict_params) errdetail = format_expr_params(estate, expr); else errdetail = NULL; ereport(ERROR, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("query returned no rows"), errdetail ? errdetail_internal("parameters: %s", errdetail) : 0)); } /* set the target to NULL(s) */ exec_move_row(estate, target, NULL, tuptab->tupdesc); } else { if (n > 1 && (stmt->strict || stmt->mod_stmt || too_many_rows_level)) { char *errdetail; int errlevel; if (estate->func->print_strict_params) errdetail = format_expr_params(estate, expr); else errdetail = NULL; errlevel = (stmt->strict || stmt->mod_stmt) ? ERROR : too_many_rows_level; ereport(errlevel, (errcode(ERRCODE_TOO_MANY_ROWS), errmsg("query returned more than one row"), errdetail ? errdetail_internal("parameters: %s", errdetail) : 0, errhint("Make sure the query returns a single row, or use LIMIT 1."))); } /* Put the first result row into the target */ exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc); } /* Clean up */ exec_eval_cleanup(estate); SPI_freetuptable(SPI_tuptable); } else { /* If the statement returned a tuple table, complain */ if (SPI_tuptable != NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query has no destination for result data"), (rc == SPI_OK_SELECT) ? errhint("If you want to discard the results of a SELECT, use PERFORM instead.") : 0)); } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_dynexecute Execute a dynamic SQL query * (possibly with INTO). * ---------- */ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynexecute *stmt) { Datum query; bool isnull; Oid restype; int32 restypmod; char *querystr; int exec_res; ParamListInfo paramLI; SPIExecuteOptions options; MemoryContext stmt_mcontext = get_stmt_mcontext(estate); /* * First we evaluate the string expression after the EXECUTE keyword. Its * result is the querystring we have to execute. */ query = exec_eval_expr(estate, stmt->query, &isnull, &restype, &restypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(estate, query, restype); /* copy it into the stmt_mcontext before we clean up */ querystr = MemoryContextStrdup(stmt_mcontext, querystr); exec_eval_cleanup(estate); /* * Execute the query without preparing a saved plan. */ paramLI = exec_eval_using_params(estate, stmt->params); memset(&options, 0, sizeof(options)); options.params = paramLI; options.read_only = estate->readonly_func; exec_res = SPI_execute_extended(querystr, &options); switch (exec_res) { case SPI_OK_SELECT: case SPI_OK_INSERT: case SPI_OK_UPDATE: case SPI_OK_DELETE: case SPI_OK_INSERT_RETURNING: case SPI_OK_UPDATE_RETURNING: case SPI_OK_DELETE_RETURNING: case SPI_OK_MERGE: case SPI_OK_UTILITY: case SPI_OK_REWRITTEN: break; case 0: /* * Also allow a zero return, which implies the querystring * contained no commands. */ break; case SPI_OK_SELINTO: /* * We want to disallow SELECT INTO for now, because its behavior * is not consistent with SELECT INTO in a normal plpgsql context. * (We need to reimplement EXECUTE to parse the string as a * plpgsql command, not just feed it to SPI_execute.) This is not * a functional limitation because CREATE TABLE AS is allowed. */ ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("EXECUTE of SELECT ... INTO is not implemented"), errhint("You might want to use EXECUTE ... INTO or EXECUTE CREATE TABLE ... AS instead."))); break; /* Some SPI errors deserve specific error messages */ case SPI_ERROR_COPY: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot COPY to/from client in PL/pgSQL"))); break; case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("EXECUTE of transaction commands is not implemented"))); break; default: elog(ERROR, "SPI_execute_extended failed executing query \"%s\": %s", querystr, SPI_result_code_string(exec_res)); break; } /* Save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; /* Process INTO if present */ if (stmt->into) { SPITupleTable *tuptab = SPI_tuptable; uint64 n = SPI_processed; PLpgSQL_variable *target; /* If the statement did not return a tuple table, complain */ if (tuptab == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("INTO used with a command that cannot return data"))); /* Fetch target's datum entry */ target = (PLpgSQL_variable *) estate->datums[stmt->target->dno]; /* * If SELECT ... INTO specified STRICT, and the query didn't find * exactly one row, throw an error. If STRICT was not specified, then * allow the query to find any number of rows. */ if (n == 0) { if (stmt->strict) { char *errdetail; if (estate->func->print_strict_params) errdetail = format_preparedparamsdata(estate, paramLI); else errdetail = NULL; ereport(ERROR, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("query returned no rows"), errdetail ? errdetail_internal("parameters: %s", errdetail) : 0)); } /* set the target to NULL(s) */ exec_move_row(estate, target, NULL, tuptab->tupdesc); } else { if (n > 1 && stmt->strict) { char *errdetail; if (estate->func->print_strict_params) errdetail = format_preparedparamsdata(estate, paramLI); else errdetail = NULL; ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ROWS), errmsg("query returned more than one row"), errdetail ? errdetail_internal("parameters: %s", errdetail) : 0)); } /* Put the first result row into the target */ exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc); } /* clean up after exec_move_row() */ exec_eval_cleanup(estate); } else { /* * It might be a good idea to raise an error if the query returned * tuples that are being ignored, but historically we have not done * that. */ } /* Release any result from SPI_execute, as well as transient data */ SPI_freetuptable(SPI_tuptable); MemoryContextReset(stmt_mcontext); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_dynfors Execute a dynamic query, assign each * tuple to a record or row and * execute a group of statements * for it. * ---------- */ static int exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt) { Portal portal; int rc; portal = exec_dynquery_with_params(estate, stmt->query, stmt->params, NULL, CURSOR_OPT_NO_SCROLL); /* * Execute the loop */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true); /* * Close the implicit cursor */ SPI_cursor_close(portal); return rc; } /* ---------- * exec_stmt_open Execute an OPEN cursor statement * ---------- */ static int exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt) { PLpgSQL_var *curvar; MemoryContext stmt_mcontext = NULL; char *curname = NULL; PLpgSQL_expr *query; Portal portal; ParamListInfo paramLI; /* ---------- * Get the cursor variable and if it has an assigned name, check * that it's not in use currently. * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (!curvar->isnull) { MemoryContext oldcontext; /* We only need stmt_mcontext to hold the cursor name string */ stmt_mcontext = get_stmt_mcontext(estate); oldcontext = MemoryContextSwitchTo(stmt_mcontext); curname = TextDatumGetCString(curvar->value); MemoryContextSwitchTo(oldcontext); if (SPI_cursor_find(curname) != NULL) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_CURSOR), errmsg("cursor \"%s\" already in use", curname))); } /* ---------- * Process the OPEN according to it's type. * ---------- */ if (stmt->query != NULL) { /* ---------- * This is an OPEN refcursor FOR SELECT ... * * We just make sure the query is planned. The real work is * done downstairs. * ---------- */ query = stmt->query; if (query->plan == NULL) exec_prepare_plan(estate, query, stmt->cursor_options); } else if (stmt->dynquery != NULL) { /* ---------- * This is an OPEN refcursor FOR EXECUTE ... * ---------- */ portal = exec_dynquery_with_params(estate, stmt->dynquery, stmt->params, curname, stmt->cursor_options); /* * If cursor variable was NULL, store the generated portal name in it, * after verifying it's okay to assign to. * * Note: exec_dynquery_with_params already reset the stmt_mcontext, so * curname is a dangling pointer here; but testing it for nullness is * OK. */ if (curname == NULL) { exec_check_assignable(estate, stmt->curvar); assign_text_var(estate, curvar, portal->name); } return PLPGSQL_RC_OK; } else { /* ---------- * This is an OPEN cursor * * Note: parser should already have checked that statement supplies * args iff cursor needs them, but we check again to be safe. * ---------- */ if (stmt->argquery != NULL) { /* ---------- * OPEN CURSOR with args. We fake a SELECT ... INTO ... * statement to evaluate the args and put 'em into the * internal row. * ---------- */ PLpgSQL_stmt_execsql set_args; if (curvar->cursor_explicit_argrow < 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments given for cursor without arguments"))); memset(&set_args, 0, sizeof(set_args)); set_args.cmd_type = PLPGSQL_STMT_EXECSQL; set_args.lineno = stmt->lineno; set_args.sqlstmt = stmt->argquery; set_args.into = true; /* XXX historically this has not been STRICT */ set_args.target = (PLpgSQL_variable *) (estate->datums[curvar->cursor_explicit_argrow]); if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK) elog(ERROR, "open cursor failed during argument processing"); } else { if (curvar->cursor_explicit_argrow >= 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments required for cursor"))); } query = curvar->cursor_explicit_expr; if (query->plan == NULL) exec_prepare_plan(estate, query, curvar->cursor_options); } /* * Set up ParamListInfo for this query */ paramLI = setup_param_list(estate, query); /* * Open the cursor (the paramlist will get copied into the portal) */ portal = SPI_cursor_open_with_paramlist(curname, query->plan, paramLI, estate->readonly_func); if (portal == NULL) elog(ERROR, "could not open cursor: %s", SPI_result_code_string(SPI_result)); /* * If cursor variable was NULL, store the generated portal name in it, * after verifying it's okay to assign to. */ if (curname == NULL) { exec_check_assignable(estate, stmt->curvar); assign_text_var(estate, curvar, portal->name); } /* If we had any transient data, clean it up */ exec_eval_cleanup(estate); if (stmt_mcontext) MemoryContextReset(stmt_mcontext); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_fetch Fetch from a cursor into a target, or just * move the current position of the cursor * ---------- */ static int exec_stmt_fetch(PLpgSQL_execstate *estate, PLpgSQL_stmt_fetch *stmt) { PLpgSQL_var *curvar; long how_many = stmt->how_many; SPITupleTable *tuptab; Portal portal; char *curname; uint64 n; MemoryContext oldcontext; /* ---------- * Get the portal of the cursor by name * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (curvar->isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("cursor variable \"%s\" is null", curvar->refname))); /* Use eval_mcontext for short-lived string */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); curname = TextDatumGetCString(curvar->value); MemoryContextSwitchTo(oldcontext); portal = SPI_cursor_find(curname); if (portal == NULL) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_CURSOR), errmsg("cursor \"%s\" does not exist", curname))); /* Calculate position for FETCH_RELATIVE or FETCH_ABSOLUTE */ if (stmt->expr) { bool isnull; /* XXX should be doing this in LONG not INT width */ how_many = exec_eval_integer(estate, stmt->expr, &isnull); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("relative or absolute cursor position is null"))); exec_eval_cleanup(estate); } if (!stmt->is_move) { PLpgSQL_variable *target; /* ---------- * Fetch 1 tuple from the cursor * ---------- */ SPI_scroll_cursor_fetch(portal, stmt->direction, how_many); tuptab = SPI_tuptable; n = SPI_processed; /* ---------- * Set the target appropriately. * ---------- */ target = (PLpgSQL_variable *) estate->datums[stmt->target->dno]; if (n == 0) exec_move_row(estate, target, NULL, tuptab->tupdesc); else exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc); exec_eval_cleanup(estate); SPI_freetuptable(tuptab); } else { /* Move the cursor */ SPI_scroll_cursor_move(portal, stmt->direction, how_many); n = SPI_processed; } /* Set the ROW_COUNT and the global FOUND variable appropriately. */ estate->eval_processed = n; exec_set_found(estate, n != 0); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_close Close a cursor * ---------- */ static int exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt) { PLpgSQL_var *curvar; Portal portal; char *curname; MemoryContext oldcontext; /* ---------- * Get the portal of the cursor by name * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (curvar->isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("cursor variable \"%s\" is null", curvar->refname))); /* Use eval_mcontext for short-lived string */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); curname = TextDatumGetCString(curvar->value); MemoryContextSwitchTo(oldcontext); portal = SPI_cursor_find(curname); if (portal == NULL) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_CURSOR), errmsg("cursor \"%s\" does not exist", curname))); /* ---------- * And close it. * ---------- */ SPI_cursor_close(portal); return PLPGSQL_RC_OK; } /* * exec_stmt_commit * * Commit the transaction. */ static int exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt) { if (stmt->chain) SPI_commit_and_chain(); else SPI_commit(); /* * We need to build new simple-expression infrastructure, since the old * data structures are gone. */ estate->simple_eval_estate = NULL; estate->simple_eval_resowner = NULL; plpgsql_create_econtext(estate); return PLPGSQL_RC_OK; } /* * exec_stmt_rollback * * Abort the transaction. */ static int exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt) { if (stmt->chain) SPI_rollback_and_chain(); else SPI_rollback(); /* * We need to build new simple-expression infrastructure, since the old * data structures are gone. */ estate->simple_eval_estate = NULL; estate->simple_eval_resowner = NULL; plpgsql_create_econtext(estate); return PLPGSQL_RC_OK; } /* ---------- * exec_assign_expr Put an expression's result into a variable. * ---------- */ static void exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target, PLpgSQL_expr *expr) { Datum value; bool isnull; Oid valtype; int32 valtypmod; /* * If first time through, create a plan for this expression. */ if (expr->plan == NULL) { /* * Mark the expression as being an assignment source, if target is a * simple variable. (This is a bit messy, but it seems cleaner than * modifying the API of exec_prepare_plan for the purpose. We need to * stash the target dno into the expr anyway, so that it will be * available if we have to replan.) */ if (target->dtype == PLPGSQL_DTYPE_VAR) expr->target_param = target->dno; else expr->target_param = -1; /* should be that already */ exec_prepare_plan(estate, expr, 0); } value = exec_eval_expr(estate, expr, &isnull, &valtype, &valtypmod); exec_assign_value(estate, target, value, isnull, valtype, valtypmod); exec_eval_cleanup(estate); } /* ---------- * exec_assign_c_string Put a C string into a text variable. * * We take a NULL pointer as signifying empty string, not SQL null. * * As with the underlying exec_assign_value, caller is expected to do * exec_eval_cleanup later. * ---------- */ static void exec_assign_c_string(PLpgSQL_execstate *estate, PLpgSQL_datum *target, const char *str) { text *value; MemoryContext oldcontext; /* Use eval_mcontext for short-lived text value */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); if (str != NULL) value = cstring_to_text(str); else value = cstring_to_text(""); MemoryContextSwitchTo(oldcontext); exec_assign_value(estate, target, PointerGetDatum(value), false, TEXTOID, -1); } /* ---------- * exec_assign_value Put a value into a target datum * * Note: in some code paths, this will leak memory in the eval_mcontext; * we assume that will be cleaned up later by exec_eval_cleanup. We cannot * call exec_eval_cleanup here for fear of destroying the input Datum value. * ---------- */ static void exec_assign_value(PLpgSQL_execstate *estate, PLpgSQL_datum *target, Datum value, bool isNull, Oid valtype, int32 valtypmod) { switch (target->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: { /* * Target is a variable */ PLpgSQL_var *var = (PLpgSQL_var *) target; Datum newvalue; newvalue = exec_cast_value(estate, value, &isNull, valtype, valtypmod, var->datatype->typoid, var->datatype->atttypmod); if (isNull && var->notnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("null value cannot be assigned to variable \"%s\" declared NOT NULL", var->refname))); /* * If type is by-reference, copy the new value (which is * probably in the eval_mcontext) into the procedure's main * memory context. But if it's a read/write reference to an * expanded object, no physical copy needs to happen; at most * we need to reparent the object's memory context. * * If it's an array, we force the value to be stored in R/W * expanded form. This wins if the function later does, say, * a lot of array subscripting operations on the variable, and * otherwise might lose. We might need to use a different * heuristic, but it's too soon to tell. Also, are there * cases where it'd be useful to force non-array values into * expanded form? */ if (!var->datatype->typbyval && !isNull) { if (var->datatype->typisarray && !VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(newvalue))) { /* array and not already R/W, so apply expand_array */ newvalue = expand_array(newvalue, estate->datum_context, NULL); } else { /* else transfer value if R/W, else just datumCopy */ newvalue = datumTransfer(newvalue, false, var->datatype->typlen); } } /* * Now free the old value, if any, and assign the new one. But * skip the assignment if old and new values are the same. * Note that for expanded objects, this test is necessary and * cannot reliably be made any earlier; we have to be looking * at the object's standard R/W pointer to be sure pointer * equality is meaningful. * * Also, if it's a promise variable, we should disarm the * promise in any case --- otherwise, assigning null to an * armed promise variable would fail to disarm the promise. */ if (var->value != newvalue || var->isnull || isNull) assign_simple_var(estate, var, newvalue, isNull, (!var->datatype->typbyval && !isNull)); else var->promise = PLPGSQL_PROMISE_NONE; break; } case PLPGSQL_DTYPE_ROW: { /* * Target is a row variable */ PLpgSQL_row *row = (PLpgSQL_row *) target; if (isNull) { /* If source is null, just assign nulls to the row */ exec_move_row(estate, (PLpgSQL_variable *) row, NULL, NULL); } else { /* Source must be of RECORD or composite type */ if (!type_is_rowtype(valtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot assign non-composite value to a row variable"))); exec_move_row_from_datum(estate, (PLpgSQL_variable *) row, value); } break; } case PLPGSQL_DTYPE_REC: { /* * Target is a record variable */ PLpgSQL_rec *rec = (PLpgSQL_rec *) target; if (isNull) { if (rec->notnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("null value cannot be assigned to variable \"%s\" declared NOT NULL", rec->refname))); /* Set variable to a simple NULL */ exec_move_row(estate, (PLpgSQL_variable *) rec, NULL, NULL); } else { /* Source must be of RECORD or composite type */ if (!type_is_rowtype(valtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot assign non-composite value to a record variable"))); exec_move_row_from_datum(estate, (PLpgSQL_variable *) rec, value); } break; } case PLPGSQL_DTYPE_RECFIELD: { /* * Target is a field of a record */ PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) target; PLpgSQL_rec *rec; ExpandedRecordHeader *erh; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); erh = rec->erh; /* * If record variable is NULL, instantiate it if it has a * named composite type, else complain. (This won't change * the logical state of the record, but if we successfully * assign below, the unassigned fields will all become NULLs.) */ if (erh == NULL) { instantiate_empty_record_variable(estate, rec); erh = rec->erh; } /* * Look up the field's properties if we have not already, or * if the tuple descriptor ID changed since last time. */ if (unlikely(recfield->rectupledescid != erh->er_tupdesc_id)) { if (!expanded_record_lookup_field(erh, recfield->fieldname, &recfield->finfo)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); recfield->rectupledescid = erh->er_tupdesc_id; } /* We don't support assignments to system columns. */ if (recfield->finfo.fnumber <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot assign to system column \"%s\"", recfield->fieldname))); /* Cast the new value to the right type, if needed. */ value = exec_cast_value(estate, value, &isNull, valtype, valtypmod, recfield->finfo.ftypeid, recfield->finfo.ftypmod); /* And assign it. */ expanded_record_set_field(erh, recfield->finfo.fnumber, value, isNull, !estate->atomic); break; } default: elog(ERROR, "unrecognized dtype: %d", target->dtype); } } /* * exec_eval_datum Get current value of a PLpgSQL_datum * * The type oid, typmod, value in Datum format, and null flag are returned. * * At present this doesn't handle PLpgSQL_expr datums; that's not needed * because we never pass references to such datums to SPI. * * NOTE: the returned Datum points right at the stored value in the case of * pass-by-reference datatypes. Generally callers should take care not to * modify the stored value. Some callers intentionally manipulate variables * referenced by R/W expanded pointers, though; it is those callers' * responsibility that the results are semantically OK. * * In some cases we have to palloc a return value, and in such cases we put * it into the estate's eval_mcontext. */ static void exec_eval_datum(PLpgSQL_execstate *estate, PLpgSQL_datum *datum, Oid *typeid, int32 *typetypmod, Datum *value, bool *isnull) { MemoryContext oldcontext; switch (datum->dtype) { case PLPGSQL_DTYPE_PROMISE: /* fulfill promise if needed, then handle like regular var */ plpgsql_fulfill_promise(estate, (PLpgSQL_var *) datum); /* FALL THRU */ case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) datum; *typeid = var->datatype->typoid; *typetypmod = var->datatype->atttypmod; *value = var->value; *isnull = var->isnull; break; } case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) datum; HeapTuple tup; /* We get here if there are multiple OUT parameters */ if (!row->rowtupdesc) /* should not happen */ elog(ERROR, "row variable has no tupdesc"); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(row->rowtupdesc); oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); tup = make_tuple_from_row(estate, row, row->rowtupdesc); if (tup == NULL) /* should not happen */ elog(ERROR, "row not compatible with its own tupdesc"); *typeid = row->rowtupdesc->tdtypeid; *typetypmod = row->rowtupdesc->tdtypmod; *value = HeapTupleGetDatum(tup); *isnull = false; MemoryContextSwitchTo(oldcontext); break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->erh == NULL) { /* Treat uninstantiated record as a simple NULL */ *value = (Datum) 0; *isnull = true; /* Report variable's declared type */ *typeid = rec->rectypeid; *typetypmod = -1; } else { if (ExpandedRecordIsEmpty(rec->erh)) { /* Empty record is also a NULL */ *value = (Datum) 0; *isnull = true; } else { *value = ExpandedRecordGetDatum(rec->erh); *isnull = false; } if (rec->rectypeid != RECORDOID) { /* Report variable's declared type, if not RECORD */ *typeid = rec->rectypeid; *typetypmod = -1; } else { /* Report record's actual type if declared RECORD */ *typeid = rec->erh->er_typeid; *typetypmod = rec->erh->er_typmod; } } break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; ExpandedRecordHeader *erh; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); erh = rec->erh; /* * If record variable is NULL, instantiate it if it has a * named composite type, else complain. (This won't change * the logical state of the record: it's still NULL.) */ if (erh == NULL) { instantiate_empty_record_variable(estate, rec); erh = rec->erh; } /* * Look up the field's properties if we have not already, or * if the tuple descriptor ID changed since last time. */ if (unlikely(recfield->rectupledescid != erh->er_tupdesc_id)) { if (!expanded_record_lookup_field(erh, recfield->fieldname, &recfield->finfo)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); recfield->rectupledescid = erh->er_tupdesc_id; } /* Report type data. */ *typeid = recfield->finfo.ftypeid; *typetypmod = recfield->finfo.ftypmod; /* And fetch the field value. */ *value = expanded_record_get_field(erh, recfield->finfo.fnumber, isnull); break; } default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); } } /* * plpgsql_exec_get_datum_type Get datatype of a PLpgSQL_datum * * This is the same logic as in exec_eval_datum, but we skip acquiring * the actual value of the variable. Also, needn't support DTYPE_ROW. */ Oid plpgsql_exec_get_datum_type(PLpgSQL_execstate *estate, PLpgSQL_datum *datum) { Oid typeid; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: { PLpgSQL_var *var = (PLpgSQL_var *) datum; typeid = var->datatype->typoid; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->erh == NULL || rec->rectypeid != RECORDOID) { /* Report variable's declared type */ typeid = rec->rectypeid; } else { /* Report record's actual type if declared RECORD */ typeid = rec->erh->er_typeid; } break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); /* * If record variable is NULL, instantiate it if it has a * named composite type, else complain. (This won't change * the logical state of the record: it's still NULL.) */ if (rec->erh == NULL) instantiate_empty_record_variable(estate, rec); /* * Look up the field's properties if we have not already, or * if the tuple descriptor ID changed since last time. */ if (unlikely(recfield->rectupledescid != rec->erh->er_tupdesc_id)) { if (!expanded_record_lookup_field(rec->erh, recfield->fieldname, &recfield->finfo)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); recfield->rectupledescid = rec->erh->er_tupdesc_id; } typeid = recfield->finfo.ftypeid; break; } default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); typeid = InvalidOid; /* keep compiler quiet */ break; } return typeid; } /* * plpgsql_exec_get_datum_type_info Get datatype etc of a PLpgSQL_datum * * An extended version of plpgsql_exec_get_datum_type, which also retrieves the * typmod and collation of the datum. Note however that we don't report the * possibly-mutable typmod of RECORD values, but say -1 always. */ void plpgsql_exec_get_datum_type_info(PLpgSQL_execstate *estate, PLpgSQL_datum *datum, Oid *typeId, int32 *typMod, Oid *collation) { switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: { PLpgSQL_var *var = (PLpgSQL_var *) datum; *typeId = var->datatype->typoid; *typMod = var->datatype->atttypmod; *collation = var->datatype->collation; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->erh == NULL || rec->rectypeid != RECORDOID) { /* Report variable's declared type */ *typeId = rec->rectypeid; *typMod = -1; } else { /* Report record's actual type if declared RECORD */ *typeId = rec->erh->er_typeid; /* do NOT return the mutable typmod of a RECORD variable */ *typMod = -1; } /* composite types are never collatable */ *collation = InvalidOid; break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); /* * If record variable is NULL, instantiate it if it has a * named composite type, else complain. (This won't change * the logical state of the record: it's still NULL.) */ if (rec->erh == NULL) instantiate_empty_record_variable(estate, rec); /* * Look up the field's properties if we have not already, or * if the tuple descriptor ID changed since last time. */ if (unlikely(recfield->rectupledescid != rec->erh->er_tupdesc_id)) { if (!expanded_record_lookup_field(rec->erh, recfield->fieldname, &recfield->finfo)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); recfield->rectupledescid = rec->erh->er_tupdesc_id; } *typeId = recfield->finfo.ftypeid; *typMod = recfield->finfo.ftypmod; *collation = recfield->finfo.fcollation; break; } default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); *typeId = InvalidOid; /* keep compiler quiet */ *typMod = -1; *collation = InvalidOid; break; } } /* ---------- * exec_eval_integer Evaluate an expression, coerce result to int4 * * Note we do not do exec_eval_cleanup here; the caller must do it at * some later point. (We do this because the caller may be holding the * results of other, pass-by-reference, expression evaluations, such as * an array value to be subscripted.) * ---------- */ static int exec_eval_integer(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull) { Datum exprdatum; Oid exprtypeid; int32 exprtypmod; exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod); exprdatum = exec_cast_value(estate, exprdatum, isNull, exprtypeid, exprtypmod, INT4OID, -1); return DatumGetInt32(exprdatum); } /* ---------- * exec_eval_boolean Evaluate an expression, coerce result to bool * * Note we do not do exec_eval_cleanup here; the caller must do it at * some later point. * ---------- */ static bool exec_eval_boolean(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull) { Datum exprdatum; Oid exprtypeid; int32 exprtypmod; exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod); exprdatum = exec_cast_value(estate, exprdatum, isNull, exprtypeid, exprtypmod, BOOLOID, -1); return DatumGetBool(exprdatum); } /* ---------- * exec_eval_expr Evaluate an expression and return * the result Datum, along with data type/typmod. * * NOTE: caller must do exec_eval_cleanup when done with the Datum. * ---------- */ static Datum exec_eval_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull, Oid *rettype, int32 *rettypmod) { Datum result = 0; int rc; Form_pg_attribute attr; /* * If first time through, create a plan for this expression. */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK); /* * If this is a simple expression, bypass SPI and use the executor * directly */ if (exec_eval_simple_expr(estate, expr, &result, isNull, rettype, rettypmod)) return result; /* * Else do it the hard way via exec_run_select */ rc = exec_run_select(estate, expr, 2, NULL); if (rc != SPI_OK_SELECT) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("query did not return data"), errcontext("query: %s", expr->query))); /* * Check that the expression returns exactly one column... */ if (estate->eval_tuptable->tupdesc->natts != 1) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg_plural("query returned %d column", "query returned %d columns", estate->eval_tuptable->tupdesc->natts, estate->eval_tuptable->tupdesc->natts), errcontext("query: %s", expr->query))); /* * ... and get the column's datatype. */ attr = TupleDescAttr(estate->eval_tuptable->tupdesc, 0); *rettype = attr->atttypid; *rettypmod = attr->atttypmod; /* * If there are no rows selected, the result is a NULL of that type. */ if (estate->eval_processed == 0) { *isNull = true; return (Datum) 0; } /* * Check that the expression returned no more than one row. */ if (estate->eval_processed != 1) ereport(ERROR, (errcode(ERRCODE_CARDINALITY_VIOLATION), errmsg("query returned more than one row"), errcontext("query: %s", expr->query))); /* * Return the single result Datum. */ return SPI_getbinval(estate->eval_tuptable->vals[0], estate->eval_tuptable->tupdesc, 1, isNull); } /* ---------- * exec_run_select Execute a select query * ---------- */ static int exec_run_select(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, long maxtuples, Portal *portalP) { ParamListInfo paramLI; int rc; /* * On the first call for this expression generate the plan. * * If we don't need to return a portal, then we're just going to execute * the query immediately, which means it's OK to use a parallel plan, even * if the number of rows being fetched is limited. If we do need to * return a portal (i.e., this is for a FOR loop), the user's code might * invoke additional operations inside the FOR loop, making parallel query * unsafe. In any case, we don't expect any cursor operations to be done, * so specify NO_SCROLL for efficiency and semantic safety. */ if (expr->plan == NULL) { int cursorOptions = CURSOR_OPT_NO_SCROLL; if (portalP == NULL) cursorOptions |= CURSOR_OPT_PARALLEL_OK; exec_prepare_plan(estate, expr, cursorOptions); } /* * Set up ParamListInfo to pass to executor */ paramLI = setup_param_list(estate, expr); /* * If a portal was requested, put the query and paramlist into the portal */ if (portalP != NULL) { *portalP = SPI_cursor_open_with_paramlist(NULL, expr->plan, paramLI, estate->readonly_func); if (*portalP == NULL) elog(ERROR, "could not open implicit cursor for query \"%s\": %s", expr->query, SPI_result_code_string(SPI_result)); exec_eval_cleanup(estate); return SPI_OK_CURSOR; } /* * Execute the query */ rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI, estate->readonly_func, maxtuples); if (rc != SPI_OK_SELECT) { /* * SELECT INTO deserves a special error message, because "query is not * a SELECT" is not very helpful in that case. */ if (rc == SPI_OK_SELINTO) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query is SELECT INTO, but it should be plain SELECT"), errcontext("query: %s", expr->query))); else ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query is not a SELECT"), errcontext("query: %s", expr->query))); } /* Save query results for eventual cleanup */ Assert(estate->eval_tuptable == NULL); estate->eval_tuptable = SPI_tuptable; estate->eval_processed = SPI_processed; return rc; } /* * exec_for_query --- execute body of FOR loop for each row from a portal * * Used by exec_stmt_fors, exec_stmt_forc and exec_stmt_dynfors */ static int exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt, Portal portal, bool prefetch_ok) { PLpgSQL_variable *var; SPITupleTable *tuptab; bool found = false; int rc = PLPGSQL_RC_OK; uint64 previous_id = INVALID_TUPLEDESC_IDENTIFIER; bool tupdescs_match = true; uint64 n; /* Fetch loop variable's datum entry */ var = (PLpgSQL_variable *) estate->datums[stmt->var->dno]; /* * Make sure the portal doesn't get closed by the user statements we * execute. */ PinPortal(portal); /* * In a non-atomic context, we dare not prefetch, even if it would * otherwise be safe. Aside from any semantic hazards that that might * create, if we prefetch toasted data and then the user commits the * transaction, the toast references could turn into dangling pointers. * (Rows we haven't yet fetched from the cursor are safe, because the * PersistHoldablePortal mechanism handles this scenario.) */ if (!estate->atomic) prefetch_ok = false; /* * Fetch the initial tuple(s). If prefetching is allowed then we grab a * few more rows to avoid multiple trips through executor startup * overhead. */ SPI_cursor_fetch(portal, true, prefetch_ok ? 10 : 1); tuptab = SPI_tuptable; n = SPI_processed; /* * If the query didn't return any rows, set the target to NULL and fall * through with found = false. */ if (n == 0) { exec_move_row(estate, var, NULL, tuptab->tupdesc); exec_eval_cleanup(estate); } else found = true; /* processed at least one tuple */ /* * Now do the loop */ while (n > 0) { uint64 i; for (i = 0; i < n; i++) { /* * Assign the tuple to the target. Here, because we know that all * loop iterations should be assigning the same tupdesc, we can * optimize away repeated creations of expanded records with * identical tupdescs. Testing for changes of er_tupdesc_id is * reliable even if the loop body contains assignments that * replace the target's value entirely, because it's assigned from * a process-global counter. The case where the tupdescs don't * match could possibly be handled more efficiently than this * coding does, but it's not clear extra effort is worthwhile. */ if (var->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) var; if (rec->erh && rec->erh->er_tupdesc_id == previous_id && tupdescs_match) { /* Only need to assign a new tuple value */ expanded_record_set_tuple(rec->erh, tuptab->vals[i], true, !estate->atomic); } else { /* * First time through, or var's tupdesc changed in loop, * or we have to do it the hard way because type coercion * is needed. */ exec_move_row(estate, var, tuptab->vals[i], tuptab->tupdesc); /* * Check to see if physical assignment is OK next time. * Once the tupdesc comparison has failed once, we don't * bother rechecking in subsequent loop iterations. */ if (tupdescs_match) { tupdescs_match = (rec->rectypeid == RECORDOID || rec->rectypeid == tuptab->tupdesc->tdtypeid || compatible_tupdescs(tuptab->tupdesc, expanded_record_get_tupdesc(rec->erh))); } previous_id = rec->erh->er_tupdesc_id; } } else exec_move_row(estate, var, tuptab->vals[i], tuptab->tupdesc); exec_eval_cleanup(estate); /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); LOOP_RC_PROCESSING(stmt->label, goto loop_exit); } SPI_freetuptable(tuptab); /* * Fetch more tuples. If prefetching is allowed, grab 50 at a time. */ SPI_cursor_fetch(portal, true, prefetch_ok ? 50 : 1); tuptab = SPI_tuptable; n = SPI_processed; } loop_exit: /* * Release last group of tuples (if any) */ SPI_freetuptable(tuptab); UnpinPortal(portal); /* * Set the FOUND variable to indicate the result of executing the loop * (namely, whether we looped one or more times). This must be set last so * that it does not interfere with the value of the FOUND variable inside * the loop processing itself. */ exec_set_found(estate, found); return rc; } /* ---------- * exec_eval_simple_expr - Evaluate a simple expression returning * a Datum by directly calling ExecEvalExpr(). * * If successful, store results into *result, *isNull, *rettype, *rettypmod * and return true. If the expression cannot be handled by simple evaluation, * return false. * * Because we only store one execution tree for a simple expression, we * can't handle recursion cases. So, if we see the tree is already busy * with an evaluation in the current xact, we just return false and let the * caller run the expression the hard way. (Other alternatives such as * creating a new tree for a recursive call either introduce memory leaks, * or add enough bookkeeping to be doubtful wins anyway.) Another case that * is covered by the expr_simple_in_use test is where a previous execution * of the tree was aborted by an error: the tree may contain bogus state * so we dare not re-use it. * * It is possible that we'd need to replan a simple expression; for example, * someone might redefine a SQL function that had been inlined into the simple * expression. That cannot cause a simple expression to become non-simple (or * vice versa), but we do have to handle replacing the expression tree. * * Note: if pass-by-reference, the result is in the eval_mcontext. * It will be freed when exec_eval_cleanup is done. * ---------- */ static bool exec_eval_simple_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, Datum *result, bool *isNull, Oid *rettype, int32 *rettypmod) { ExprContext *econtext = estate->eval_econtext; LocalTransactionId curlxid = MyProc->lxid; ParamListInfo paramLI; void *save_setup_arg; bool need_snapshot; MemoryContext oldcontext; /* * Forget it if expression wasn't simple before. */ if (expr->expr_simple_expr == NULL) return false; /* * If expression is in use in current xact, don't touch it. */ if (unlikely(expr->expr_simple_in_use) && expr->expr_simple_lxid == curlxid) return false; /* * Ensure that there's a portal-level snapshot, in case this simple * expression is the first thing evaluated after a COMMIT or ROLLBACK. * We'd have to do this anyway before executing the expression, so we * might as well do it now to ensure that any possible replanning doesn't * need to take a new snapshot. */ EnsurePortalSnapshotExists(); /* * Check to see if the cached plan has been invalidated. If not, and this * is the first use in the current transaction, save a plan refcount in * the simple-expression resowner. */ if (likely(CachedPlanIsSimplyValid(expr->expr_simple_plansource, expr->expr_simple_plan, (expr->expr_simple_plan_lxid != curlxid ? estate->simple_eval_resowner : NULL)))) { /* * It's still good, so just remember that we have a refcount on the * plan in the current transaction. (If we already had one, this * assignment is a no-op.) */ expr->expr_simple_plan_lxid = curlxid; } else { /* Need to replan */ CachedPlan *cplan; /* * If we have a valid refcount on some previous version of the plan, * release it, so we don't leak plans intra-transaction. */ if (expr->expr_simple_plan_lxid == curlxid) { ReleaseCachedPlan(expr->expr_simple_plan, estate->simple_eval_resowner); expr->expr_simple_plan = NULL; expr->expr_simple_plan_lxid = InvalidLocalTransactionId; } /* Do the replanning work in the eval_mcontext */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); cplan = SPI_plan_get_cached_plan(expr->plan); MemoryContextSwitchTo(oldcontext); /* * We can't get a failure here, because the number of * CachedPlanSources in the SPI plan can't change from what * exec_simple_check_plan saw; it's a property of the raw parsetree * generated from the query text. */ Assert(cplan != NULL); /* * This test probably can't fail either, but if it does, cope by * declaring the plan to be non-simple. On success, we'll acquire a * refcount on the new plan, stored in simple_eval_resowner. */ if (CachedPlanAllowsSimpleValidityCheck(expr->expr_simple_plansource, cplan, estate->simple_eval_resowner)) { /* Remember that we have the refcount */ expr->expr_simple_plan = cplan; expr->expr_simple_plan_lxid = curlxid; } else { /* Release SPI_plan_get_cached_plan's refcount */ ReleaseCachedPlan(cplan, CurrentResourceOwner); /* Mark expression as non-simple, and fail */ expr->expr_simple_expr = NULL; expr->expr_rw_param = NULL; return false; } /* * SPI_plan_get_cached_plan acquired a plan refcount stored in the * active resowner. We don't need that anymore, so release it. */ ReleaseCachedPlan(cplan, CurrentResourceOwner); /* Extract desired scalar expression from cached plan */ exec_save_simple_expr(expr, cplan); } /* * Pass back previously-determined result type. */ *rettype = expr->expr_simple_type; *rettypmod = expr->expr_simple_typmod; /* * Set up ParamListInfo to pass to executor. For safety, save and restore * estate->paramLI->parserSetupArg around our use of the param list. */ paramLI = estate->paramLI; save_setup_arg = paramLI->parserSetupArg; /* * We can skip using setup_param_list() in favor of just doing this * unconditionally, because there's no need for the optimization of * possibly setting ecxt_param_list_info to NULL; we've already forced use * of a generic plan. */ paramLI->parserSetupArg = (void *) expr; econtext->ecxt_param_list_info = paramLI; /* * Prepare the expression for execution, if it's not been done already in * the current transaction. (This will be forced to happen if we called * exec_save_simple_expr above.) */ if (unlikely(expr->expr_simple_lxid != curlxid)) { oldcontext = MemoryContextSwitchTo(estate->simple_eval_estate->es_query_cxt); expr->expr_simple_state = ExecInitExprWithParams(expr->expr_simple_expr, econtext->ecxt_param_list_info); expr->expr_simple_in_use = false; expr->expr_simple_lxid = curlxid; MemoryContextSwitchTo(oldcontext); } /* * We have to do some of the things SPI_execute_plan would do, in * particular push a new snapshot so that stable functions within the * expression can see updates made so far by our own function. However, * we can skip doing that (and just invoke the expression with the same * snapshot passed to our function) in some cases, which is useful because * it's quite expensive relative to the cost of a simple expression. We * can skip it if the expression contains no stable or volatile functions; * immutable functions shouldn't need to see our updates. Also, if this * is a read-only function, we haven't made any updates so again it's okay * to skip. */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); need_snapshot = (expr->expr_simple_mutable && !estate->readonly_func); if (need_snapshot) { CommandCounterIncrement(); PushActiveSnapshot(GetTransactionSnapshot()); } /* * Mark expression as busy for the duration of the ExecEvalExpr call. */ expr->expr_simple_in_use = true; /* * Finally we can call the executor to evaluate the expression */ *result = ExecEvalExpr(expr->expr_simple_state, econtext, isNull); /* Assorted cleanup */ expr->expr_simple_in_use = false; econtext->ecxt_param_list_info = NULL; paramLI->parserSetupArg = save_setup_arg; if (need_snapshot) PopActiveSnapshot(); MemoryContextSwitchTo(oldcontext); /* * That's it. */ return true; } /* * Create a ParamListInfo to pass to SPI * * We use a single ParamListInfo struct for all SPI calls made to evaluate * PLpgSQL_exprs in this estate. It contains no per-param data, just hook * functions, so it's effectively read-only for SPI. * * An exception from pure read-only-ness is that the parserSetupArg points * to the specific PLpgSQL_expr being evaluated. This is not an issue for * statement-level callers, but lower-level callers must save and restore * estate->paramLI->parserSetupArg just in case there's an active evaluation * at an outer call level. (A plausible alternative design would be to * create a ParamListInfo struct for each PLpgSQL_expr, but for the moment * that seems like a waste of memory.) */ static ParamListInfo setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr) { ParamListInfo paramLI; /* * We must have created the SPIPlan already (hence, query text has been * parsed/analyzed at least once); else we cannot rely on expr->paramnos. */ Assert(expr->plan != NULL); /* * We only need a ParamListInfo if the expression has parameters. */ if (!bms_is_empty(expr->paramnos)) { /* Use the common ParamListInfo */ paramLI = estate->paramLI; /* * Set up link to active expr where the hook functions can find it. * Callers must save and restore parserSetupArg if there is any chance * that they are interrupting an active use of parameters. */ paramLI->parserSetupArg = (void *) expr; /* * Also make sure this is set before parser hooks need it. There is * no need to save and restore, since the value is always correct once * set. (Should be set already, but let's be sure.) */ expr->func = estate->func; } else { /* * Expression requires no parameters. Be sure we represent this case * as a NULL ParamListInfo, so that plancache.c knows there is no * point in a custom plan. */ paramLI = NULL; } return paramLI; } /* * plpgsql_param_fetch paramFetch callback for dynamic parameter fetch * * We always use the caller's workspace to construct the returned struct. * * Note: this is no longer used during query execution. It is used during * planning (with speculative == true) and when the ParamListInfo we supply * to the executor is copied into a cursor portal or transferred to a * parallel child process. */ static ParamExternData * plpgsql_param_fetch(ParamListInfo params, int paramid, bool speculative, ParamExternData *prm) { int dno; PLpgSQL_execstate *estate; PLpgSQL_expr *expr; PLpgSQL_datum *datum; bool ok = true; int32 prmtypmod; /* paramid's are 1-based, but dnos are 0-based */ dno = paramid - 1; Assert(dno >= 0 && dno < params->numParams); /* fetch back the hook data */ estate = (PLpgSQL_execstate *) params->paramFetchArg; expr = (PLpgSQL_expr *) params->parserSetupArg; Assert(params->numParams == estate->ndatums); /* now we can access the target datum */ datum = estate->datums[dno]; /* * Since copyParamList() or SerializeParamList() will try to materialize * every single parameter slot, it's important to return a dummy param * when asked for a datum that's not supposed to be used by this SQL * expression. Otherwise we risk failures in exec_eval_datum(), or * copying a lot more data than necessary. */ if (!bms_is_member(dno, expr->paramnos)) ok = false; /* * If the access is speculative, we prefer to return no data rather than * to fail in exec_eval_datum(). Check the likely failure cases. */ else if (speculative) { switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: /* always safe */ break; case PLPGSQL_DTYPE_ROW: /* should be safe in all interesting cases */ break; case PLPGSQL_DTYPE_REC: /* always safe (might return NULL, that's fine) */ break; case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); /* * If record variable is NULL, don't risk anything. */ if (rec->erh == NULL) ok = false; /* * Look up the field's properties if we have not already, * or if the tuple descriptor ID changed since last time. */ else if (unlikely(recfield->rectupledescid != rec->erh->er_tupdesc_id)) { if (expanded_record_lookup_field(rec->erh, recfield->fieldname, &recfield->finfo)) recfield->rectupledescid = rec->erh->er_tupdesc_id; else ok = false; } break; } default: ok = false; break; } } /* Return "no such parameter" if not ok */ if (!ok) { prm->value = (Datum) 0; prm->isnull = true; prm->pflags = 0; prm->ptype = InvalidOid; return prm; } /* OK, evaluate the value and store into the return struct */ exec_eval_datum(estate, datum, &prm->ptype, &prmtypmod, &prm->value, &prm->isnull); /* We can always mark params as "const" for executor's purposes */ prm->pflags = PARAM_FLAG_CONST; /* * If it's a read/write expanded datum, convert reference to read-only. * (There's little point in trying to optimize read/write parameters, * given the cases in which this function is used.) */ if (datum->dtype == PLPGSQL_DTYPE_VAR) prm->value = MakeExpandedObjectReadOnly(prm->value, prm->isnull, ((PLpgSQL_var *) datum)->datatype->typlen); else if (datum->dtype == PLPGSQL_DTYPE_REC) prm->value = MakeExpandedObjectReadOnly(prm->value, prm->isnull, -1); return prm; } /* * plpgsql_param_compile paramCompile callback for plpgsql parameters */ static void plpgsql_param_compile(ParamListInfo params, Param *param, ExprState *state, Datum *resv, bool *resnull) { PLpgSQL_execstate *estate; PLpgSQL_expr *expr; int dno; PLpgSQL_datum *datum; ExprEvalStep scratch; /* fetch back the hook data */ estate = (PLpgSQL_execstate *) params->paramFetchArg; expr = (PLpgSQL_expr *) params->parserSetupArg; /* paramid's are 1-based, but dnos are 0-based */ dno = param->paramid - 1; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ datum = estate->datums[dno]; scratch.opcode = EEOP_PARAM_CALLBACK; scratch.resvalue = resv; scratch.resnull = resnull; /* * Select appropriate eval function. It seems worth special-casing * DTYPE_VAR and DTYPE_RECFIELD for performance. Also, we can determine * in advance whether MakeExpandedObjectReadOnly() will be required. * Currently, only VAR/PROMISE and REC datums could contain read/write * expanded objects. */ if (datum->dtype == PLPGSQL_DTYPE_VAR) { if (param != expr->expr_rw_param && ((PLpgSQL_var *) datum)->datatype->typlen == -1) scratch.d.cparam.paramfunc = plpgsql_param_eval_var_ro; else scratch.d.cparam.paramfunc = plpgsql_param_eval_var; } else if (datum->dtype == PLPGSQL_DTYPE_RECFIELD) scratch.d.cparam.paramfunc = plpgsql_param_eval_recfield; else if (datum->dtype == PLPGSQL_DTYPE_PROMISE) { if (param != expr->expr_rw_param && ((PLpgSQL_var *) datum)->datatype->typlen == -1) scratch.d.cparam.paramfunc = plpgsql_param_eval_generic_ro; else scratch.d.cparam.paramfunc = plpgsql_param_eval_generic; } else if (datum->dtype == PLPGSQL_DTYPE_REC && param != expr->expr_rw_param) scratch.d.cparam.paramfunc = plpgsql_param_eval_generic_ro; else scratch.d.cparam.paramfunc = plpgsql_param_eval_generic; /* * Note: it's tempting to use paramarg to store the estate pointer and * thereby save an indirection or two in the eval functions. But that * doesn't work because the compiled expression might be used with * different estates for the same PL/pgSQL function. */ scratch.d.cparam.paramarg = NULL; scratch.d.cparam.paramid = param->paramid; scratch.d.cparam.paramtype = param->paramtype; ExprEvalPushStep(state, &scratch); } /* * plpgsql_param_eval_var evaluation of EEOP_PARAM_CALLBACK step * * This is specialized to the case of DTYPE_VAR variables for which * we do not need to invoke MakeExpandedObjectReadOnly. */ static void plpgsql_param_eval_var(ExprState *state, ExprEvalStep *op, ExprContext *econtext) { ParamListInfo params; PLpgSQL_execstate *estate; int dno = op->d.cparam.paramid - 1; PLpgSQL_var *var; /* fetch back the hook data */ params = econtext->ecxt_param_list_info; estate = (PLpgSQL_execstate *) params->paramFetchArg; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ var = (PLpgSQL_var *) estate->datums[dno]; Assert(var->dtype == PLPGSQL_DTYPE_VAR); /* inlined version of exec_eval_datum() */ *op->resvalue = var->value; *op->resnull = var->isnull; /* safety check -- an assertion should be sufficient */ Assert(var->datatype->typoid == op->d.cparam.paramtype); } /* * plpgsql_param_eval_var_ro evaluation of EEOP_PARAM_CALLBACK step * * This is specialized to the case of DTYPE_VAR variables for which * we need to invoke MakeExpandedObjectReadOnly. */ static void plpgsql_param_eval_var_ro(ExprState *state, ExprEvalStep *op, ExprContext *econtext) { ParamListInfo params; PLpgSQL_execstate *estate; int dno = op->d.cparam.paramid - 1; PLpgSQL_var *var; /* fetch back the hook data */ params = econtext->ecxt_param_list_info; estate = (PLpgSQL_execstate *) params->paramFetchArg; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ var = (PLpgSQL_var *) estate->datums[dno]; Assert(var->dtype == PLPGSQL_DTYPE_VAR); /* * Inlined version of exec_eval_datum() ... and while we're at it, force * expanded datums to read-only. */ *op->resvalue = MakeExpandedObjectReadOnly(var->value, var->isnull, -1); *op->resnull = var->isnull; /* safety check -- an assertion should be sufficient */ Assert(var->datatype->typoid == op->d.cparam.paramtype); } /* * plpgsql_param_eval_recfield evaluation of EEOP_PARAM_CALLBACK step * * This is specialized to the case of DTYPE_RECFIELD variables, for which * we never need to invoke MakeExpandedObjectReadOnly. */ static void plpgsql_param_eval_recfield(ExprState *state, ExprEvalStep *op, ExprContext *econtext) { ParamListInfo params; PLpgSQL_execstate *estate; int dno = op->d.cparam.paramid - 1; PLpgSQL_recfield *recfield; PLpgSQL_rec *rec; ExpandedRecordHeader *erh; /* fetch back the hook data */ params = econtext->ecxt_param_list_info; estate = (PLpgSQL_execstate *) params->paramFetchArg; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ recfield = (PLpgSQL_recfield *) estate->datums[dno]; Assert(recfield->dtype == PLPGSQL_DTYPE_RECFIELD); /* inline the relevant part of exec_eval_datum */ rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); erh = rec->erh; /* * If record variable is NULL, instantiate it if it has a named composite * type, else complain. (This won't change the logical state of the * record: it's still NULL.) */ if (erh == NULL) { instantiate_empty_record_variable(estate, rec); erh = rec->erh; } /* * Look up the field's properties if we have not already, or if the tuple * descriptor ID changed since last time. */ if (unlikely(recfield->rectupledescid != erh->er_tupdesc_id)) { if (!expanded_record_lookup_field(erh, recfield->fieldname, &recfield->finfo)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); recfield->rectupledescid = erh->er_tupdesc_id; } /* OK to fetch the field value. */ *op->resvalue = expanded_record_get_field(erh, recfield->finfo.fnumber, op->resnull); /* safety check -- needed for, eg, record fields */ if (unlikely(recfield->finfo.ftypeid != op->d.cparam.paramtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("type of parameter %d (%s) does not match that when preparing the plan (%s)", op->d.cparam.paramid, format_type_be(recfield->finfo.ftypeid), format_type_be(op->d.cparam.paramtype)))); } /* * plpgsql_param_eval_generic evaluation of EEOP_PARAM_CALLBACK step * * This handles all variable types, but assumes we do not need to invoke * MakeExpandedObjectReadOnly. */ static void plpgsql_param_eval_generic(ExprState *state, ExprEvalStep *op, ExprContext *econtext) { ParamListInfo params; PLpgSQL_execstate *estate; int dno = op->d.cparam.paramid - 1; PLpgSQL_datum *datum; Oid datumtype; int32 datumtypmod; /* fetch back the hook data */ params = econtext->ecxt_param_list_info; estate = (PLpgSQL_execstate *) params->paramFetchArg; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ datum = estate->datums[dno]; /* fetch datum's value */ exec_eval_datum(estate, datum, &datumtype, &datumtypmod, op->resvalue, op->resnull); /* safety check -- needed for, eg, record fields */ if (unlikely(datumtype != op->d.cparam.paramtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("type of parameter %d (%s) does not match that when preparing the plan (%s)", op->d.cparam.paramid, format_type_be(datumtype), format_type_be(op->d.cparam.paramtype)))); } /* * plpgsql_param_eval_generic_ro evaluation of EEOP_PARAM_CALLBACK step * * This handles all variable types, but assumes we need to invoke * MakeExpandedObjectReadOnly (hence, variable must be of a varlena type). */ static void plpgsql_param_eval_generic_ro(ExprState *state, ExprEvalStep *op, ExprContext *econtext) { ParamListInfo params; PLpgSQL_execstate *estate; int dno = op->d.cparam.paramid - 1; PLpgSQL_datum *datum; Oid datumtype; int32 datumtypmod; /* fetch back the hook data */ params = econtext->ecxt_param_list_info; estate = (PLpgSQL_execstate *) params->paramFetchArg; Assert(dno >= 0 && dno < estate->ndatums); /* now we can access the target datum */ datum = estate->datums[dno]; /* fetch datum's value */ exec_eval_datum(estate, datum, &datumtype, &datumtypmod, op->resvalue, op->resnull); /* safety check -- needed for, eg, record fields */ if (unlikely(datumtype != op->d.cparam.paramtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("type of parameter %d (%s) does not match that when preparing the plan (%s)", op->d.cparam.paramid, format_type_be(datumtype), format_type_be(op->d.cparam.paramtype)))); /* force the value to read-only */ *op->resvalue = MakeExpandedObjectReadOnly(*op->resvalue, *op->resnull, -1); } /* * exec_move_row Move one tuple's values into a record or row * * tup and tupdesc may both be NULL if we're just assigning an indeterminate * composite NULL to the target. Alternatively, can have tup be NULL and * tupdesc not NULL, in which case we assign a row of NULLs to the target. * * Since this uses the mcontext for workspace, caller should eventually call * exec_eval_cleanup to prevent long-term memory leaks. */ static void exec_move_row(PLpgSQL_execstate *estate, PLpgSQL_variable *target, HeapTuple tup, TupleDesc tupdesc) { ExpandedRecordHeader *newerh = NULL; /* * If target is RECORD, we may be able to avoid field-by-field processing. */ if (target->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) target; /* * If we have no source tupdesc, just set the record variable to NULL. * (If we have a source tupdesc but not a tuple, we'll set the * variable to a row of nulls, instead. This is odd perhaps, but * backwards compatible.) */ if (tupdesc == NULL) { if (rec->datatype && rec->datatype->typtype == TYPTYPE_DOMAIN) { /* * If it's a composite domain, NULL might not be a legal * value, so we instead need to make an empty expanded record * and ensure that domain type checking gets done. If there * is already an expanded record, piggyback on its lookups. */ newerh = make_expanded_record_for_rec(estate, rec, NULL, rec->erh); expanded_record_set_tuple(newerh, NULL, false, false); assign_record_var(estate, rec, newerh); } else { /* Just clear it to NULL */ if (rec->erh) DeleteExpandedObject(ExpandedRecordGetDatum(rec->erh)); rec->erh = NULL; } return; } /* * Build a new expanded record with appropriate tupdesc. */ newerh = make_expanded_record_for_rec(estate, rec, tupdesc, NULL); /* * If the rowtypes match, or if we have no tuple anyway, we can * complete the assignment without field-by-field processing. * * The tests here are ordered more or less in order of cheapness. We * can easily detect it will work if the target is declared RECORD or * has the same typeid as the source. But when assigning from a query * result, it's common to have a source tupdesc that's labeled RECORD * but is actually physically compatible with a named-composite-type * target, so it's worth spending extra cycles to check for that. */ if (rec->rectypeid == RECORDOID || rec->rectypeid == tupdesc->tdtypeid || !HeapTupleIsValid(tup) || compatible_tupdescs(tupdesc, expanded_record_get_tupdesc(newerh))) { if (!HeapTupleIsValid(tup)) { /* No data, so force the record into all-nulls state */ deconstruct_expanded_record(newerh); } else { /* No coercion is needed, so just assign the row value */ expanded_record_set_tuple(newerh, tup, true, !estate->atomic); } /* Complete the assignment */ assign_record_var(estate, rec, newerh); return; } } /* * Otherwise, deconstruct the tuple and do field-by-field assignment, * using exec_move_row_from_fields. */ if (tupdesc && HeapTupleIsValid(tup)) { int td_natts = tupdesc->natts; Datum *values; bool *nulls; Datum values_local[64]; bool nulls_local[64]; /* * Need workspace arrays. If td_natts is small enough, use local * arrays to save doing a palloc. Even if it's not small, we can * allocate both the Datum and isnull arrays in one palloc chunk. */ if (td_natts <= lengthof(values_local)) { values = values_local; nulls = nulls_local; } else { char *chunk; chunk = eval_mcontext_alloc(estate, td_natts * (sizeof(Datum) + sizeof(bool))); values = (Datum *) chunk; nulls = (bool *) (chunk + td_natts * sizeof(Datum)); } heap_deform_tuple(tup, tupdesc, values, nulls); exec_move_row_from_fields(estate, target, newerh, values, nulls, tupdesc); } else { /* * Assign all-nulls. */ exec_move_row_from_fields(estate, target, newerh, NULL, NULL, NULL); } } /* * Verify that a PLpgSQL_rec's rectypeid is up-to-date. */ static void revalidate_rectypeid(PLpgSQL_rec *rec) { PLpgSQL_type *typ = rec->datatype; TypeCacheEntry *typentry; if (rec->rectypeid == RECORDOID) return; /* it's RECORD, so nothing to do */ Assert(typ != NULL); if (typ->tcache && typ->tcache->tupDesc_identifier == typ->tupdesc_id) { /* * Although *typ is known up-to-date, it's possible that rectypeid * isn't, because *rec is cloned during each function startup from a * copy that we don't have a good way to update. Hence, forcibly fix * rectypeid before returning. */ rec->rectypeid = typ->typoid; return; } /* * typcache entry has suffered invalidation, so re-look-up the type name * if possible, and then recheck the type OID. If we don't have a * TypeName, then we just have to soldier on with the OID we've got. */ if (typ->origtypname != NULL) { /* this bit should match parse_datatype() in pl_gram.y */ typenameTypeIdAndMod(NULL, typ->origtypname, &typ->typoid, &typ->atttypmod); } /* this bit should match build_datatype() in pl_comp.c */ typentry = lookup_type_cache(typ->typoid, TYPECACHE_TUPDESC | TYPECACHE_DOMAIN_BASE_INFO); if (typentry->typtype == TYPTYPE_DOMAIN) typentry = lookup_type_cache(typentry->domainBaseType, TYPECACHE_TUPDESC); if (typentry->tupDesc == NULL) { /* * If we get here, user tried to replace a composite type with a * non-composite one. We're not gonna support that. */ ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("type %s is not composite", format_type_be(typ->typoid)))); } /* * Update tcache and tupdesc_id. Since we don't support changing to a * non-composite type, none of the rest of *typ needs to change. */ typ->tcache = typentry; typ->tupdesc_id = typentry->tupDesc_identifier; /* * Update *rec, too. (We'll deal with subsidiary RECFIELDs as needed.) */ rec->rectypeid = typ->typoid; } /* * Build an expanded record object suitable for assignment to "rec". * * Caller must supply either a source tuple descriptor or a source expanded * record (not both). If the record variable has declared type RECORD, * it'll adopt the source's rowtype. Even if it doesn't, we may be able to * piggyback on a source expanded record to save a typcache lookup. * * Caller must fill the object with data, then do assign_record_var(). * * The new record is initially put into the mcontext, so it will be cleaned up * if we fail before reaching assign_record_var(). */ static ExpandedRecordHeader * make_expanded_record_for_rec(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, TupleDesc srctupdesc, ExpandedRecordHeader *srcerh) { ExpandedRecordHeader *newerh; MemoryContext mcontext = get_eval_mcontext(estate); if (rec->rectypeid != RECORDOID) { /* * Make sure rec->rectypeid is up-to-date before using it. */ revalidate_rectypeid(rec); /* * New record must be of desired type, but maybe srcerh has already * done all the same lookups. */ if (srcerh && rec->rectypeid == srcerh->er_decltypeid) newerh = make_expanded_record_from_exprecord(srcerh, mcontext); else newerh = make_expanded_record_from_typeid(rec->rectypeid, -1, mcontext); } else { /* * We'll adopt the input tupdesc. We can still use * make_expanded_record_from_exprecord, if srcerh isn't a composite * domain. (If it is, we effectively adopt its base type.) */ if (srcerh && !ExpandedRecordIsDomain(srcerh)) newerh = make_expanded_record_from_exprecord(srcerh, mcontext); else { if (!srctupdesc) srctupdesc = expanded_record_get_tupdesc(srcerh); newerh = make_expanded_record_from_tupdesc(srctupdesc, mcontext); } } return newerh; } /* * exec_move_row_from_fields Move arrays of field values into a record or row * * When assigning to a record, the caller must have already created a suitable * new expanded record object, newerh. Pass NULL when assigning to a row. * * tupdesc describes the input row, which might have different column * types and/or different dropped-column positions than the target. * values/nulls/tupdesc can all be NULL if we just want to assign nulls to * all fields of the record or row. * * Since this uses the mcontext for workspace, caller should eventually call * exec_eval_cleanup to prevent long-term memory leaks. */ static void exec_move_row_from_fields(PLpgSQL_execstate *estate, PLpgSQL_variable *target, ExpandedRecordHeader *newerh, Datum *values, bool *nulls, TupleDesc tupdesc) { int td_natts = tupdesc ? tupdesc->natts : 0; int fnum; int anum; int strict_multiassignment_level = 0; /* * The extra check strict strict_multi_assignment can be active, only when * input tupdesc is specified. */ if (tupdesc != NULL) { if (plpgsql_extra_errors & PLPGSQL_XCHECK_STRICTMULTIASSIGNMENT) strict_multiassignment_level = ERROR; else if (plpgsql_extra_warnings & PLPGSQL_XCHECK_STRICTMULTIASSIGNMENT) strict_multiassignment_level = WARNING; } /* Handle RECORD-target case */ if (target->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) target; TupleDesc var_tupdesc; Datum newvalues_local[64]; bool newnulls_local[64]; Assert(newerh != NULL); /* caller must have built new object */ var_tupdesc = expanded_record_get_tupdesc(newerh); /* * Coerce field values if needed. This might involve dealing with * different sets of dropped columns and/or coercing individual column * types. That's sort of a pain, but historically plpgsql has allowed * it, so we preserve the behavior. However, it's worth a quick check * to see if the tupdescs are identical. (Since expandedrecord.c * prefers to use refcounted tupdescs from the typcache, expanded * records with the same rowtype will have pointer-equal tupdescs.) */ if (var_tupdesc != tupdesc) { int vtd_natts = var_tupdesc->natts; Datum *newvalues; bool *newnulls; /* * Need workspace arrays. If vtd_natts is small enough, use local * arrays to save doing a palloc. Even if it's not small, we can * allocate both the Datum and isnull arrays in one palloc chunk. */ if (vtd_natts <= lengthof(newvalues_local)) { newvalues = newvalues_local; newnulls = newnulls_local; } else { char *chunk; chunk = eval_mcontext_alloc(estate, vtd_natts * (sizeof(Datum) + sizeof(bool))); newvalues = (Datum *) chunk; newnulls = (bool *) (chunk + vtd_natts * sizeof(Datum)); } /* Walk over destination columns */ anum = 0; for (fnum = 0; fnum < vtd_natts; fnum++) { Form_pg_attribute attr = TupleDescAttr(var_tupdesc, fnum); Datum value; bool isnull; Oid valtype; int32 valtypmod; if (attr->attisdropped) { /* expanded_record_set_fields should ignore this column */ continue; /* skip dropped column in record */ } while (anum < td_natts && TupleDescAttr(tupdesc, anum)->attisdropped) anum++; /* skip dropped column in tuple */ if (anum < td_natts) { value = values[anum]; isnull = nulls[anum]; valtype = TupleDescAttr(tupdesc, anum)->atttypid; valtypmod = TupleDescAttr(tupdesc, anum)->atttypmod; anum++; } else { /* no source for destination column */ value = (Datum) 0; isnull = true; valtype = UNKNOWNOID; valtypmod = -1; /* When source value is missing */ if (strict_multiassignment_level) ereport(strict_multiassignment_level, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("number of source and target fields in assignment does not match"), /* translator: %s represents a name of an extra check */ errdetail("%s check of %s is active.", "strict_multi_assignment", strict_multiassignment_level == ERROR ? "extra_errors" : "extra_warnings"), errhint("Make sure the query returns the exact list of columns."))); } /* Cast the new value to the right type, if needed. */ newvalues[fnum] = exec_cast_value(estate, value, &isnull, valtype, valtypmod, attr->atttypid, attr->atttypmod); newnulls[fnum] = isnull; } /* * When strict_multiassignment extra check is active, then ensure * there are no unassigned source attributes. */ if (strict_multiassignment_level && anum < td_natts) { /* skip dropped columns in the source descriptor */ while (anum < td_natts && TupleDescAttr(tupdesc, anum)->attisdropped) anum++; if (anum < td_natts) ereport(strict_multiassignment_level, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("number of source and target fields in assignment does not match"), /* translator: %s represents a name of an extra check */ errdetail("%s check of %s is active.", "strict_multi_assignment", strict_multiassignment_level == ERROR ? "extra_errors" : "extra_warnings"), errhint("Make sure the query returns the exact list of columns."))); } values = newvalues; nulls = newnulls; } /* Insert the coerced field values into the new expanded record */ expanded_record_set_fields(newerh, values, nulls, !estate->atomic); /* Complete the assignment */ assign_record_var(estate, rec, newerh); return; } /* newerh should not have been passed in non-RECORD cases */ Assert(newerh == NULL); /* * For a row, we assign the individual field values to the variables the * row points to. * * NOTE: both this code and the record code above silently ignore extra * columns in the source and assume NULL for missing columns. This is * pretty dubious but it's the historical behavior. * * If we have no input data at all, we'll assign NULL to all columns of * the row variable. */ if (target->dtype == PLPGSQL_DTYPE_ROW) { PLpgSQL_row *row = (PLpgSQL_row *) target; anum = 0; for (fnum = 0; fnum < row->nfields; fnum++) { PLpgSQL_var *var; Datum value; bool isnull; Oid valtype; int32 valtypmod; var = (PLpgSQL_var *) (estate->datums[row->varnos[fnum]]); while (anum < td_natts && TupleDescAttr(tupdesc, anum)->attisdropped) anum++; /* skip dropped column in tuple */ if (anum < td_natts) { value = values[anum]; isnull = nulls[anum]; valtype = TupleDescAttr(tupdesc, anum)->atttypid; valtypmod = TupleDescAttr(tupdesc, anum)->atttypmod; anum++; } else { /* no source for destination column */ value = (Datum) 0; isnull = true; valtype = UNKNOWNOID; valtypmod = -1; if (strict_multiassignment_level) ereport(strict_multiassignment_level, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("number of source and target fields in assignment does not match"), /* translator: %s represents a name of an extra check */ errdetail("%s check of %s is active.", "strict_multi_assignment", strict_multiassignment_level == ERROR ? "extra_errors" : "extra_warnings"), errhint("Make sure the query returns the exact list of columns."))); } exec_assign_value(estate, (PLpgSQL_datum *) var, value, isnull, valtype, valtypmod); } /* * When strict_multiassignment extra check is active, ensure there are * no unassigned source attributes. */ if (strict_multiassignment_level && anum < td_natts) { while (anum < td_natts && TupleDescAttr(tupdesc, anum)->attisdropped) anum++; /* skip dropped column in tuple */ if (anum < td_natts) ereport(strict_multiassignment_level, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("number of source and target fields in assignment does not match"), /* translator: %s represents a name of an extra check */ errdetail("%s check of %s is active.", "strict_multi_assignment", strict_multiassignment_level == ERROR ? "extra_errors" : "extra_warnings"), errhint("Make sure the query returns the exact list of columns."))); } return; } elog(ERROR, "unsupported target type: %d", target->dtype); } /* * compatible_tupdescs: detect whether two tupdescs are physically compatible * * TRUE indicates that a tuple satisfying src_tupdesc can be used directly as * a value for a composite variable using dst_tupdesc. */ static bool compatible_tupdescs(TupleDesc src_tupdesc, TupleDesc dst_tupdesc) { int i; /* Possibly we could allow src_tupdesc to have extra columns? */ if (dst_tupdesc->natts != src_tupdesc->natts) return false; for (i = 0; i < dst_tupdesc->natts; i++) { Form_pg_attribute dattr = TupleDescAttr(dst_tupdesc, i); Form_pg_attribute sattr = TupleDescAttr(src_tupdesc, i); if (dattr->attisdropped != sattr->attisdropped) return false; if (!dattr->attisdropped) { /* Normal columns must match by type and typmod */ if (dattr->atttypid != sattr->atttypid || (dattr->atttypmod >= 0 && dattr->atttypmod != sattr->atttypmod)) return false; } else { /* Dropped columns are OK as long as length/alignment match */ if (dattr->attlen != sattr->attlen || dattr->attalign != sattr->attalign) return false; } } return true; } /* ---------- * make_tuple_from_row Make a tuple from the values of a row object * * A NULL return indicates rowtype mismatch; caller must raise suitable error * * The result tuple is freshly palloc'd in caller's context. Some junk * may be left behind in eval_mcontext, too. * ---------- */ static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate, PLpgSQL_row *row, TupleDesc tupdesc) { int natts = tupdesc->natts; HeapTuple tuple; Datum *dvalues; bool *nulls; int i; if (natts != row->nfields) return NULL; dvalues = (Datum *) eval_mcontext_alloc0(estate, natts * sizeof(Datum)); nulls = (bool *) eval_mcontext_alloc(estate, natts * sizeof(bool)); for (i = 0; i < natts; i++) { Oid fieldtypeid; int32 fieldtypmod; if (TupleDescAttr(tupdesc, i)->attisdropped) { nulls[i] = true; /* leave the column as null */ continue; } exec_eval_datum(estate, estate->datums[row->varnos[i]], &fieldtypeid, &fieldtypmod, &dvalues[i], &nulls[i]); if (fieldtypeid != TupleDescAttr(tupdesc, i)->atttypid) return NULL; /* XXX should we insist on typmod match, too? */ } tuple = heap_form_tuple(tupdesc, dvalues, nulls); return tuple; } /* * deconstruct_composite_datum extract tuple+tupdesc from composite Datum * * The caller must supply a HeapTupleData variable, in which we set up a * tuple header pointing to the composite datum's body. To make the tuple * value outlive that variable, caller would need to apply heap_copytuple... * but current callers only need a short-lived tuple value anyway. * * Returns a pointer to the TupleDesc of the datum's rowtype. * Caller is responsible for calling ReleaseTupleDesc when done with it. * * Note: it's caller's responsibility to be sure value is of composite type. * Also, best to call this in a short-lived context, as it might leak memory. */ static TupleDesc deconstruct_composite_datum(Datum value, HeapTupleData *tmptup) { HeapTupleHeader td; Oid tupType; int32 tupTypmod; /* Get tuple body (note this could involve detoasting) */ td = DatumGetHeapTupleHeader(value); /* Build a temporary HeapTuple control structure */ tmptup->t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup->t_self)); tmptup->t_tableOid = InvalidOid; tmptup->t_data = td; /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); return lookup_rowtype_tupdesc(tupType, tupTypmod); } /* * exec_move_row_from_datum Move a composite Datum into a record or row * * This is equivalent to deconstruct_composite_datum() followed by * exec_move_row(), but we can optimize things if the Datum is an * expanded-record reference. * * Note: it's caller's responsibility to be sure value is of composite type. */ static void exec_move_row_from_datum(PLpgSQL_execstate *estate, PLpgSQL_variable *target, Datum value) { /* Check to see if source is an expanded record */ if (VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(value))) { ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(value); ExpandedRecordHeader *newerh = NULL; Assert(erh->er_magic == ER_MAGIC); /* These cases apply if the target is record not row... */ if (target->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) target; /* * If it's the same record already stored in the variable, do * nothing. This would happen only in silly cases like "r := r", * but we need some check to avoid possibly freeing the variable's * live value below. Note that this applies even if what we have * is a R/O pointer. */ if (erh == rec->erh) return; /* * Make sure rec->rectypeid is up-to-date before using it. */ revalidate_rectypeid(rec); /* * If we have a R/W pointer, we're allowed to just commandeer * ownership of the expanded record. If it's of the right type to * put into the record variable, do that. (Note we don't accept * an expanded record of a composite-domain type as a RECORD * value. We'll treat it as the base composite type instead; * compare logic in make_expanded_record_for_rec.) */ if (VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(value)) && (rec->rectypeid == erh->er_decltypeid || (rec->rectypeid == RECORDOID && !ExpandedRecordIsDomain(erh)))) { assign_record_var(estate, rec, erh); return; } /* * If we already have an expanded record object in the target * variable, and the source record contains a valid tuple * representation with the right rowtype, then we can skip making * a new expanded record and just assign the tuple with * expanded_record_set_tuple. (We can't do the equivalent if we * have to do field-by-field assignment, since that wouldn't be * atomic if there's an error.) We consider that there's a * rowtype match only if it's the same named composite type or * same registered rowtype; checking for matches of anonymous * rowtypes would be more expensive than this is worth. */ if (rec->erh && (erh->flags & ER_FLAG_FVALUE_VALID) && erh->er_typeid == rec->erh->er_typeid && (erh->er_typeid != RECORDOID || (erh->er_typmod == rec->erh->er_typmod && erh->er_typmod >= 0))) { expanded_record_set_tuple(rec->erh, erh->fvalue, true, !estate->atomic); return; } /* * Otherwise we're gonna need a new expanded record object. Make * it here in hopes of piggybacking on the source object's * previous typcache lookup. */ newerh = make_expanded_record_for_rec(estate, rec, NULL, erh); /* * If the expanded record contains a valid tuple representation, * and we don't need rowtype conversion, then just copying the * tuple is probably faster than field-by-field processing. (This * isn't duplicative of the previous check, since here we will * catch the case where the record variable was previously empty.) */ if ((erh->flags & ER_FLAG_FVALUE_VALID) && (rec->rectypeid == RECORDOID || rec->rectypeid == erh->er_typeid)) { expanded_record_set_tuple(newerh, erh->fvalue, true, !estate->atomic); assign_record_var(estate, rec, newerh); return; } /* * Need to special-case empty source record, else code below would * leak newerh. */ if (ExpandedRecordIsEmpty(erh)) { /* Set newerh to a row of NULLs */ deconstruct_expanded_record(newerh); assign_record_var(estate, rec, newerh); return; } } /* end of record-target-only cases */ /* * If the source expanded record is empty, we should treat that like a * NULL tuple value. (We're unlikely to see such a case, but we must * check this; deconstruct_expanded_record would cause a change of * logical state, which is not OK.) */ if (ExpandedRecordIsEmpty(erh)) { exec_move_row(estate, target, NULL, expanded_record_get_tupdesc(erh)); return; } /* * Otherwise, ensure that the source record is deconstructed, and * assign from its field values. */ deconstruct_expanded_record(erh); exec_move_row_from_fields(estate, target, newerh, erh->dvalues, erh->dnulls, expanded_record_get_tupdesc(erh)); } else { /* * Nope, we've got a plain composite Datum. Deconstruct it; but we * don't use deconstruct_composite_datum(), because we may be able to * skip calling lookup_rowtype_tupdesc(). */ HeapTupleHeader td; HeapTupleData tmptup; Oid tupType; int32 tupTypmod; TupleDesc tupdesc; MemoryContext oldcontext; /* Ensure that any detoasted data winds up in the eval_mcontext */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); /* Get tuple body (note this could involve detoasting) */ td = DatumGetHeapTupleHeader(value); MemoryContextSwitchTo(oldcontext); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; /* Extract rowtype info */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); /* Now, if the target is record not row, maybe we can optimize ... */ if (target->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) target; /* * If we already have an expanded record object in the target * variable, and the source datum has a matching rowtype, then we * can skip making a new expanded record and just assign the tuple * with expanded_record_set_tuple. We consider that there's a * rowtype match only if it's the same named composite type or * same registered rowtype. (Checking to reject an anonymous * rowtype here should be redundant, but let's be safe.) */ if (rec->erh && tupType == rec->erh->er_typeid && (tupType != RECORDOID || (tupTypmod == rec->erh->er_typmod && tupTypmod >= 0))) { expanded_record_set_tuple(rec->erh, &tmptup, true, !estate->atomic); return; } /* * If the source datum has a rowtype compatible with the target * variable, just build a new expanded record and assign the tuple * into it. Using make_expanded_record_from_typeid() here saves * one typcache lookup compared to the code below. */ if (rec->rectypeid == RECORDOID || rec->rectypeid == tupType) { ExpandedRecordHeader *newerh; MemoryContext mcontext = get_eval_mcontext(estate); newerh = make_expanded_record_from_typeid(tupType, tupTypmod, mcontext); expanded_record_set_tuple(newerh, &tmptup, true, !estate->atomic); assign_record_var(estate, rec, newerh); return; } /* * Otherwise, we're going to need conversion, so fall through to * do it the hard way. */ } /* * ROW target, or unoptimizable RECORD target, so we have to expend a * lookup to obtain the source datum's tupdesc. */ tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Do the move */ exec_move_row(estate, target, &tmptup, tupdesc); /* Release tupdesc usage count */ ReleaseTupleDesc(tupdesc); } } /* * If we have not created an expanded record to hold the record variable's * value, do so. The expanded record will be "empty", so this does not * change the logical state of the record variable: it's still NULL. * However, now we'll have a tupdesc with which we can e.g. look up fields. */ static void instantiate_empty_record_variable(PLpgSQL_execstate *estate, PLpgSQL_rec *rec) { Assert(rec->erh == NULL); /* else caller error */ /* If declared type is RECORD, we can't instantiate */ if (rec->rectypeid == RECORDOID) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); /* Make sure rec->rectypeid is up-to-date before using it */ revalidate_rectypeid(rec); /* OK, do it */ rec->erh = make_expanded_record_from_typeid(rec->rectypeid, -1, estate->datum_context); } /* ---------- * convert_value_to_string Convert a non-null Datum to C string * * Note: the result is in the estate's eval_mcontext, and will be cleared * by the next exec_eval_cleanup() call. The invoked output function might * leave additional cruft there as well, so just pfree'ing the result string * would not be enough to avoid memory leaks if we did not do it like this. * In most usages the Datum being passed in is also in that context (if * pass-by-reference) and so an exec_eval_cleanup() call is needed anyway. * * Note: not caching the conversion function lookup is bad for performance. * However, this function isn't currently used in any places where an extra * catalog lookup or two seems like a big deal. * ---------- */ static char * convert_value_to_string(PLpgSQL_execstate *estate, Datum value, Oid valtype) { char *result; MemoryContext oldcontext; Oid typoutput; bool typIsVarlena; oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); getTypeOutputInfo(valtype, &typoutput, &typIsVarlena); result = OidOutputFunctionCall(typoutput, value); MemoryContextSwitchTo(oldcontext); return result; } /* ---------- * exec_cast_value Cast a value if required * * Note that *isnull is an input and also an output parameter. While it's * unlikely that a cast operation would produce null from non-null or vice * versa, that could happen in principle. * * Note: the estate's eval_mcontext is used for temporary storage, and may * also contain the result Datum if we have to do a conversion to a pass- * by-reference data type. Be sure to do an exec_eval_cleanup() call when * done with the result. * ---------- */ static inline Datum exec_cast_value(PLpgSQL_execstate *estate, Datum value, bool *isnull, Oid valtype, int32 valtypmod, Oid reqtype, int32 reqtypmod) { /* * If the type of the given value isn't what's requested, convert it. */ if (valtype != reqtype || (valtypmod != reqtypmod && reqtypmod != -1)) { /* We keep the slow path out-of-line. */ value = do_cast_value(estate, value, isnull, valtype, valtypmod, reqtype, reqtypmod); } return value; } /* ---------- * do_cast_value Slow path for exec_cast_value. * ---------- */ static Datum do_cast_value(PLpgSQL_execstate *estate, Datum value, bool *isnull, Oid valtype, int32 valtypmod, Oid reqtype, int32 reqtypmod) { plpgsql_CastHashEntry *cast_entry; cast_entry = get_cast_hashentry(estate, valtype, valtypmod, reqtype, reqtypmod); if (cast_entry) { ExprContext *econtext = estate->eval_econtext; MemoryContext oldcontext; oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); econtext->caseValue_datum = value; econtext->caseValue_isNull = *isnull; cast_entry->cast_in_use = true; value = ExecEvalExpr(cast_entry->cast_exprstate, econtext, isnull); cast_entry->cast_in_use = false; MemoryContextSwitchTo(oldcontext); } return value; } /* ---------- * get_cast_hashentry Look up how to perform a type cast * * Returns a plpgsql_CastHashEntry if an expression has to be evaluated, * or NULL if the cast is a mere no-op relabeling. If there's work to be * done, the cast_exprstate field contains an expression evaluation tree * based on a CaseTestExpr input, and the cast_in_use field should be set * true while executing it. * ---------- */ static plpgsql_CastHashEntry * get_cast_hashentry(PLpgSQL_execstate *estate, Oid srctype, int32 srctypmod, Oid dsttype, int32 dsttypmod) { plpgsql_CastHashKey cast_key; plpgsql_CastHashEntry *cast_entry; plpgsql_CastExprHashEntry *expr_entry; bool found; LocalTransactionId curlxid; MemoryContext oldcontext; /* Look for existing entry */ cast_key.srctype = srctype; cast_key.dsttype = dsttype; cast_key.srctypmod = srctypmod; cast_key.dsttypmod = dsttypmod; cast_entry = (plpgsql_CastHashEntry *) hash_search(estate->cast_hash, &cast_key, HASH_ENTER, &found); if (!found) /* initialize if new entry */ { /* We need a second lookup to see if a cast_expr_hash entry exists */ expr_entry = (plpgsql_CastExprHashEntry *) hash_search(cast_expr_hash, &cast_key, HASH_ENTER, &found); if (!found) /* initialize if new expr entry */ expr_entry->cast_cexpr = NULL; cast_entry->cast_centry = expr_entry; cast_entry->cast_exprstate = NULL; cast_entry->cast_in_use = false; cast_entry->cast_lxid = InvalidLocalTransactionId; } else { /* Use always-valid link to avoid a second hash lookup */ expr_entry = cast_entry->cast_centry; } if (expr_entry->cast_cexpr == NULL || !expr_entry->cast_cexpr->is_valid) { /* * We've not looked up this coercion before, or we have but the cached * expression has been invalidated. */ Node *cast_expr; CachedExpression *cast_cexpr; CaseTestExpr *placeholder; /* * Drop old cached expression if there is one. */ if (expr_entry->cast_cexpr) { FreeCachedExpression(expr_entry->cast_cexpr); expr_entry->cast_cexpr = NULL; } /* * Since we could easily fail (no such coercion), construct a * temporary coercion expression tree in the short-lived * eval_mcontext, then if successful save it as a CachedExpression. */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); /* * We use a CaseTestExpr as the base of the coercion tree, since it's * very cheap to insert the source value for that. */ placeholder = makeNode(CaseTestExpr); placeholder->typeId = srctype; placeholder->typeMod = srctypmod; placeholder->collation = get_typcollation(srctype); /* * Apply coercion. We use the special coercion context * COERCION_PLPGSQL to match plpgsql's historical behavior, namely * that any cast not available at ASSIGNMENT level will be implemented * as an I/O coercion. (It's somewhat dubious that we prefer I/O * coercion over cast pathways that exist at EXPLICIT level. Changing * that would cause assorted minor behavioral differences though, and * a user who wants the explicit-cast behavior can always write an * explicit cast.) * * If source type is UNKNOWN, coerce_to_target_type will fail (it only * expects to see that for Const input nodes), so don't call it; we'll * apply CoerceViaIO instead. Likewise, it doesn't currently work for * coercing RECORD to some other type, so skip for that too. */ if (srctype == UNKNOWNOID || srctype == RECORDOID) cast_expr = NULL; else cast_expr = coerce_to_target_type(NULL, (Node *) placeholder, srctype, dsttype, dsttypmod, COERCION_PLPGSQL, COERCE_IMPLICIT_CAST, -1); /* * If there's no cast path according to the parser, fall back to using * an I/O coercion; this is semantically dubious but matches plpgsql's * historical behavior. We would need something of the sort for * UNKNOWN literals in any case. (This is probably now only reachable * in the case where srctype is UNKNOWN/RECORD.) */ if (cast_expr == NULL) { CoerceViaIO *iocoerce = makeNode(CoerceViaIO); iocoerce->arg = (Expr *) placeholder; iocoerce->resulttype = dsttype; iocoerce->resultcollid = InvalidOid; iocoerce->coerceformat = COERCE_IMPLICIT_CAST; iocoerce->location = -1; cast_expr = (Node *) iocoerce; if (dsttypmod != -1) cast_expr = coerce_to_target_type(NULL, cast_expr, dsttype, dsttype, dsttypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); } /* Note: we don't bother labeling the expression tree with collation */ /* Plan the expression and build a CachedExpression */ cast_cexpr = GetCachedExpression(cast_expr); cast_expr = cast_cexpr->expr; /* Detect whether we have a no-op (RelabelType) coercion */ if (IsA(cast_expr, RelabelType) && ((RelabelType *) cast_expr)->arg == (Expr *) placeholder) cast_expr = NULL; /* Now we can fill in the expression hashtable entry. */ expr_entry->cast_cexpr = cast_cexpr; expr_entry->cast_expr = (Expr *) cast_expr; /* Be sure to reset the exprstate hashtable entry, too. */ cast_entry->cast_exprstate = NULL; cast_entry->cast_in_use = false; cast_entry->cast_lxid = InvalidLocalTransactionId; MemoryContextSwitchTo(oldcontext); } /* Done if we have determined that this is a no-op cast. */ if (expr_entry->cast_expr == NULL) return NULL; /* * Prepare the expression for execution, if it's not been done already in * the current transaction; also, if it's marked busy in the current * transaction, abandon that expression tree and build a new one, so as to * avoid potential problems with recursive cast expressions and failed * executions. (We will leak some memory intra-transaction if that * happens a lot, but we don't expect it to.) It's okay to update the * hash table with the new tree because all plpgsql functions within a * given transaction share the same simple_eval_estate. (Well, regular * functions do; DO blocks have private simple_eval_estates, and private * cast hash tables to go with them.) */ curlxid = MyProc->lxid; if (cast_entry->cast_lxid != curlxid || cast_entry->cast_in_use) { oldcontext = MemoryContextSwitchTo(estate->simple_eval_estate->es_query_cxt); cast_entry->cast_exprstate = ExecInitExpr(expr_entry->cast_expr, NULL); cast_entry->cast_in_use = false; cast_entry->cast_lxid = curlxid; MemoryContextSwitchTo(oldcontext); } return cast_entry; } /* ---------- * exec_simple_check_plan - Check if a plan is simple enough to * be evaluated by ExecEvalExpr() instead * of SPI. * * Note: the refcount manipulations in this function assume that expr->plan * is a "saved" SPI plan. That's a bit annoying from the caller's standpoint, * but it's otherwise difficult to avoid leaking the plan on failure. * ---------- */ static void exec_simple_check_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr) { List *plansources; CachedPlanSource *plansource; Query *query; CachedPlan *cplan; MemoryContext oldcontext; /* * Initialize to "not simple". */ expr->expr_simple_expr = NULL; expr->expr_rw_param = NULL; /* * Check the analyzed-and-rewritten form of the query to see if we will be * able to treat it as a simple expression. Since this function is only * called immediately after creating the CachedPlanSource, we need not * worry about the query being stale. */ /* * We can only test queries that resulted in exactly one CachedPlanSource */ plansources = SPI_plan_get_plan_sources(expr->plan); if (list_length(plansources) != 1) return; plansource = (CachedPlanSource *) linitial(plansources); /* * 1. There must be one single querytree. */ if (list_length(plansource->query_list) != 1) return; query = (Query *) linitial(plansource->query_list); /* * 2. It must be a plain SELECT query without any input tables */ if (!IsA(query, Query)) return; if (query->commandType != CMD_SELECT) return; if (query->rtable != NIL) return; /* * 3. Can't have any subplans, aggregates, qual clauses either. (These * tests should generally match what inline_function() checks before * inlining a SQL function; otherwise, inlining could change our * conclusion about whether an expression is simple, which we don't want.) */ if (query->hasAggs || query->hasWindowFuncs || query->hasTargetSRFs || query->hasSubLinks || query->cteList || query->jointree->fromlist || query->jointree->quals || query->groupClause || query->groupingSets || query->havingQual || query->windowClause || query->distinctClause || query->sortClause || query->limitOffset || query->limitCount || query->setOperations) return; /* * 4. The query must have a single attribute as result */ if (list_length(query->targetList) != 1) return; /* * OK, we can treat it as a simple plan. * * Get the generic plan for the query. If replanning is needed, do that * work in the eval_mcontext. (Note that replanning could throw an error, * in which case the expr is left marked "not simple", which is fine.) */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); cplan = SPI_plan_get_cached_plan(expr->plan); MemoryContextSwitchTo(oldcontext); /* Can't fail, because we checked for a single CachedPlanSource above */ Assert(cplan != NULL); /* * Verify that plancache.c thinks the plan is simple enough to use * CachedPlanIsSimplyValid. Given the restrictions above, it's unlikely * that this could fail, but if it does, just treat plan as not simple. On * success, save a refcount on the plan in the simple-expression resowner. */ if (CachedPlanAllowsSimpleValidityCheck(plansource, cplan, estate->simple_eval_resowner)) { /* Remember that we have the refcount */ expr->expr_simple_plansource = plansource; expr->expr_simple_plan = cplan; expr->expr_simple_plan_lxid = MyProc->lxid; /* Share the remaining work with the replan code path */ exec_save_simple_expr(expr, cplan); } /* * Release the plan refcount obtained by SPI_plan_get_cached_plan. (This * refcount is held by the wrong resowner, so we can't just repurpose it.) */ ReleaseCachedPlan(cplan, CurrentResourceOwner); } /* * exec_save_simple_expr --- extract simple expression from CachedPlan */ static void exec_save_simple_expr(PLpgSQL_expr *expr, CachedPlan *cplan) { PlannedStmt *stmt; Plan *plan; Expr *tle_expr; /* * Given the checks that exec_simple_check_plan did, none of the Asserts * here should ever fail. */ /* Extract the single PlannedStmt */ Assert(list_length(cplan->stmt_list) == 1); stmt = linitial_node(PlannedStmt, cplan->stmt_list); Assert(stmt->commandType == CMD_SELECT); /* * Ordinarily, the plan node should be a simple Result. However, if * debug_parallel_query is on, the planner might've stuck a Gather node * atop that. The simplest way to deal with this is to look through the * Gather node. The Gather node's tlist would normally contain a Var * referencing the child node's output, but it could also be a Param, or * it could be a Const that setrefs.c copied as-is. */ plan = stmt->planTree; for (;;) { /* Extract the single tlist expression */ Assert(list_length(plan->targetlist) == 1); tle_expr = linitial_node(TargetEntry, plan->targetlist)->expr; if (IsA(plan, Result)) { Assert(plan->lefttree == NULL && plan->righttree == NULL && plan->initPlan == NULL && plan->qual == NULL && ((Result *) plan)->resconstantqual == NULL); break; } else if (IsA(plan, Gather)) { Assert(plan->lefttree != NULL && plan->righttree == NULL && plan->initPlan == NULL && plan->qual == NULL); /* If setrefs.c copied up a Const, no need to look further */ if (IsA(tle_expr, Const)) break; /* Otherwise, it had better be a Param or an outer Var */ Assert(IsA(tle_expr, Param) || (IsA(tle_expr, Var) && ((Var *) tle_expr)->varno == OUTER_VAR)); /* Descend to the child node */ plan = plan->lefttree; } else elog(ERROR, "unexpected plan node type: %d", (int) nodeTag(plan)); } /* * Save the simple expression, and initialize state to "not valid in * current transaction". */ expr->expr_simple_expr = tle_expr; expr->expr_simple_state = NULL; expr->expr_simple_in_use = false; expr->expr_simple_lxid = InvalidLocalTransactionId; /* Also stash away the expression result type */ expr->expr_simple_type = exprType((Node *) tle_expr); expr->expr_simple_typmod = exprTypmod((Node *) tle_expr); /* We also want to remember if it is immutable or not */ expr->expr_simple_mutable = contain_mutable_functions((Node *) tle_expr); /* * Lastly, check to see if there's a possibility of optimizing a * read/write parameter. */ exec_check_rw_parameter(expr); } /* * exec_check_rw_parameter --- can we pass expanded object as read/write param? * * If we have an assignment like "x := array_append(x, foo)" in which the * top-level function is trusted not to corrupt its argument in case of an * error, then when x has an expanded object as value, it is safe to pass the * value as a read/write pointer and let the function modify the value * in-place. * * This function checks for a safe expression, and sets expr->expr_rw_param * to the address of any Param within the expression that can be passed as * read/write (there can be only one); or to NULL when there is no safe Param. * * Note that this mechanism intentionally applies the safety labeling to just * one Param; the expression could contain other Params referencing the target * variable, but those must still be treated as read-only. * * Also note that we only apply this optimization within simple expressions. * There's no point in it for non-simple expressions, because the * exec_run_select code path will flatten any expanded result anyway. * Also, it's safe to assume that an expr_simple_expr tree won't get copied * somewhere before it gets compiled, so that looking for pointer equality * to expr_rw_param will work for matching the target Param. That'd be much * shakier in the general case. */ static void exec_check_rw_parameter(PLpgSQL_expr *expr) { int target_dno; Oid funcid; List *fargs; ListCell *lc; /* Assume unsafe */ expr->expr_rw_param = NULL; /* Done if expression isn't an assignment source */ target_dno = expr->target_param; if (target_dno < 0) return; /* * If target variable isn't referenced by expression, no need to look * further. */ if (!bms_is_member(target_dno, expr->paramnos)) return; /* Shouldn't be here for non-simple expression */ Assert(expr->expr_simple_expr != NULL); /* * Top level of expression must be a simple FuncExpr, OpExpr, or * SubscriptingRef, else we can't optimize. */ if (IsA(expr->expr_simple_expr, FuncExpr)) { FuncExpr *fexpr = (FuncExpr *) expr->expr_simple_expr; funcid = fexpr->funcid; fargs = fexpr->args; } else if (IsA(expr->expr_simple_expr, OpExpr)) { OpExpr *opexpr = (OpExpr *) expr->expr_simple_expr; funcid = opexpr->opfuncid; fargs = opexpr->args; } else if (IsA(expr->expr_simple_expr, SubscriptingRef)) { SubscriptingRef *sbsref = (SubscriptingRef *) expr->expr_simple_expr; /* We only trust standard varlena arrays to be safe */ if (get_typsubscript(sbsref->refcontainertype, NULL) != F_ARRAY_SUBSCRIPT_HANDLER) return; /* We can optimize the refexpr if it's the target, otherwise not */ if (sbsref->refexpr && IsA(sbsref->refexpr, Param)) { Param *param = (Param *) sbsref->refexpr; if (param->paramkind == PARAM_EXTERN && param->paramid == target_dno + 1) { /* Found the Param we want to pass as read/write */ expr->expr_rw_param = param; return; } } return; } else return; /* * The top-level function must be one that we trust to be "safe". * Currently we hard-wire the list, but it would be very desirable to * allow extensions to mark their functions as safe ... */ if (!(funcid == F_ARRAY_APPEND || funcid == F_ARRAY_PREPEND)) return; /* * The target variable (in the form of a Param) must appear as a direct * argument of the top-level function. References further down in the * tree can't be optimized; but on the other hand, they don't invalidate * optimizing the top-level call, since that will be executed last. */ foreach(lc, fargs) { Node *arg = (Node *) lfirst(lc); if (arg && IsA(arg, Param)) { Param *param = (Param *) arg; if (param->paramkind == PARAM_EXTERN && param->paramid == target_dno + 1) { /* Found the Param we want to pass as read/write */ expr->expr_rw_param = param; return; } } } } /* * exec_check_assignable --- is it OK to assign to the indicated datum? * * This should match pl_gram.y's check_assignable(). */ static void exec_check_assignable(PLpgSQL_execstate *estate, int dno) { PLpgSQL_datum *datum; Assert(dno >= 0 && dno < estate->ndatums); datum = estate->datums[dno]; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: case PLPGSQL_DTYPE_PROMISE: case PLPGSQL_DTYPE_REC: if (((PLpgSQL_variable *) datum)->isconst) ereport(ERROR, (errcode(ERRCODE_ERROR_IN_ASSIGNMENT), errmsg("variable \"%s\" is declared CONSTANT", ((PLpgSQL_variable *) datum)->refname))); break; case PLPGSQL_DTYPE_ROW: /* always assignable; member vars were checked at compile time */ break; case PLPGSQL_DTYPE_RECFIELD: /* assignable if parent record is */ exec_check_assignable(estate, ((PLpgSQL_recfield *) datum)->recparentno); break; default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); break; } } /* ---------- * exec_set_found Set the global found variable to true/false * ---------- */ static void exec_set_found(PLpgSQL_execstate *estate, bool state) { PLpgSQL_var *var; var = (PLpgSQL_var *) (estate->datums[estate->found_varno]); assign_simple_var(estate, var, BoolGetDatum(state), false, false); } /* * plpgsql_create_econtext --- create an eval_econtext for the current function * * We may need to create a new shared_simple_eval_estate too, if there's not * one already for the current transaction. The EState will be cleaned up at * transaction end. Ditto for shared_simple_eval_resowner. */ static void plpgsql_create_econtext(PLpgSQL_execstate *estate) { SimpleEcontextStackEntry *entry; /* * Create an EState for evaluation of simple expressions, if there's not * one already in the current transaction. The EState is made a child of * TopTransactionContext so it will have the right lifespan. * * Note that this path is never taken when beginning a DO block; the * required EState was already made by plpgsql_inline_handler. However, * if the DO block executes COMMIT or ROLLBACK, then we'll come here and * make a shared EState to use for the rest of the DO block. That's OK; * see the comments for shared_simple_eval_estate. (Note also that a DO * block will continue to use its private cast hash table for the rest of * the block. That's okay for now, but it might cause problems someday.) */ if (estate->simple_eval_estate == NULL) { MemoryContext oldcontext; if (shared_simple_eval_estate == NULL) { oldcontext = MemoryContextSwitchTo(TopTransactionContext); shared_simple_eval_estate = CreateExecutorState(); MemoryContextSwitchTo(oldcontext); } estate->simple_eval_estate = shared_simple_eval_estate; } /* * Likewise for the simple-expression resource owner. */ if (estate->simple_eval_resowner == NULL) { if (shared_simple_eval_resowner == NULL) shared_simple_eval_resowner = ResourceOwnerCreate(TopTransactionResourceOwner, "PL/pgSQL simple expressions"); estate->simple_eval_resowner = shared_simple_eval_resowner; } /* * Create a child econtext for the current function. */ estate->eval_econtext = CreateExprContext(estate->simple_eval_estate); /* * Make a stack entry so we can clean up the econtext at subxact end. * Stack entries are kept in TopTransactionContext for simplicity. */ entry = (SimpleEcontextStackEntry *) MemoryContextAlloc(TopTransactionContext, sizeof(SimpleEcontextStackEntry)); entry->stack_econtext = estate->eval_econtext; entry->xact_subxid = GetCurrentSubTransactionId(); entry->next = simple_econtext_stack; simple_econtext_stack = entry; } /* * plpgsql_destroy_econtext --- destroy function's econtext * * We check that it matches the top stack entry, and destroy the stack * entry along with the context. */ static void plpgsql_destroy_econtext(PLpgSQL_execstate *estate) { SimpleEcontextStackEntry *next; Assert(simple_econtext_stack != NULL); Assert(simple_econtext_stack->stack_econtext == estate->eval_econtext); next = simple_econtext_stack->next; pfree(simple_econtext_stack); simple_econtext_stack = next; FreeExprContext(estate->eval_econtext, true); estate->eval_econtext = NULL; } /* * plpgsql_xact_cb --- post-transaction-commit-or-abort cleanup * * If a simple-expression EState was created in the current transaction, * it has to be cleaned up. The same for the simple-expression resowner. */ void plpgsql_xact_cb(XactEvent event, void *arg) { /* * If we are doing a clean transaction shutdown, free the EState and tell * the resowner to release whatever plancache references it has, so that * all remaining resources will be released correctly. (We don't need to * actually delete the resowner here; deletion of the * TopTransactionResourceOwner will take care of that.) * * In an abort, we expect the regular abort recovery procedures to release * everything of interest, so just clear our pointers. */ if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PARALLEL_COMMIT || event == XACT_EVENT_PREPARE) { simple_econtext_stack = NULL; if (shared_simple_eval_estate) FreeExecutorState(shared_simple_eval_estate); shared_simple_eval_estate = NULL; if (shared_simple_eval_resowner) ReleaseAllPlanCacheRefsInOwner(shared_simple_eval_resowner); shared_simple_eval_resowner = NULL; } else if (event == XACT_EVENT_ABORT || event == XACT_EVENT_PARALLEL_ABORT) { simple_econtext_stack = NULL; shared_simple_eval_estate = NULL; shared_simple_eval_resowner = NULL; } } /* * plpgsql_subxact_cb --- post-subtransaction-commit-or-abort cleanup * * Make sure any simple-expression econtexts created in the current * subtransaction get cleaned up. We have to do this explicitly because * no other code knows which econtexts belong to which level of subxact. */ void plpgsql_subxact_cb(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg) { if (event == SUBXACT_EVENT_COMMIT_SUB || event == SUBXACT_EVENT_ABORT_SUB) { while (simple_econtext_stack != NULL && simple_econtext_stack->xact_subxid == mySubid) { SimpleEcontextStackEntry *next; FreeExprContext(simple_econtext_stack->stack_econtext, (event == SUBXACT_EVENT_COMMIT_SUB)); next = simple_econtext_stack->next; pfree(simple_econtext_stack); simple_econtext_stack = next; } } } /* * assign_simple_var --- assign a new value to any VAR datum. * * This should be the only mechanism for assignment to simple variables, * lest we do the release of the old value incorrectly (not to mention * the detoasting business). */ static void assign_simple_var(PLpgSQL_execstate *estate, PLpgSQL_var *var, Datum newvalue, bool isnull, bool freeable) { Assert(var->dtype == PLPGSQL_DTYPE_VAR || var->dtype == PLPGSQL_DTYPE_PROMISE); /* * In non-atomic contexts, we do not want to store TOAST pointers in * variables, because such pointers might become stale after a commit. * Forcibly detoast in such cases. We don't want to detoast (flatten) * expanded objects, however; those should be OK across a transaction * boundary since they're just memory-resident objects. (Elsewhere in * this module, operations on expanded records likewise need to request * detoasting of record fields when !estate->atomic. Expanded arrays are * not a problem since all array entries are always detoasted.) */ if (!estate->atomic && !isnull && var->datatype->typlen == -1 && VARATT_IS_EXTERNAL_NON_EXPANDED(DatumGetPointer(newvalue))) { MemoryContext oldcxt; Datum detoasted; /* * Do the detoasting in the eval_mcontext to avoid long-term leakage * of whatever memory toast fetching might leak. Then we have to copy * the detoasted datum to the function's main context, which is a * pain, but there's little choice. */ oldcxt = MemoryContextSwitchTo(get_eval_mcontext(estate)); detoasted = PointerGetDatum(detoast_external_attr((struct varlena *) DatumGetPointer(newvalue))); MemoryContextSwitchTo(oldcxt); /* Now's a good time to not leak the input value if it's freeable */ if (freeable) pfree(DatumGetPointer(newvalue)); /* Once we copy the value, it's definitely freeable */ newvalue = datumCopy(detoasted, false, -1); freeable = true; /* Can't clean up eval_mcontext here, but it'll happen before long */ } /* Free the old value if needed */ if (var->freeval) { if (DatumIsReadWriteExpandedObject(var->value, var->isnull, var->datatype->typlen)) DeleteExpandedObject(var->value); else pfree(DatumGetPointer(var->value)); } /* Assign new value to datum */ var->value = newvalue; var->isnull = isnull; var->freeval = freeable; /* * If it's a promise variable, then either we just assigned the promised * value, or the user explicitly assigned an overriding value. Either * way, cancel the promise. */ var->promise = PLPGSQL_PROMISE_NONE; } /* * free old value of a text variable and assign new value from C string */ static void assign_text_var(PLpgSQL_execstate *estate, PLpgSQL_var *var, const char *str) { assign_simple_var(estate, var, CStringGetTextDatum(str), false, true); } /* * assign_record_var --- assign a new value to any REC datum. */ static void assign_record_var(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, ExpandedRecordHeader *erh) { Assert(rec->dtype == PLPGSQL_DTYPE_REC); /* Transfer new record object into datum_context */ TransferExpandedRecord(erh, estate->datum_context); /* Free the old value ... */ if (rec->erh) DeleteExpandedObject(ExpandedRecordGetDatum(rec->erh)); /* ... and install the new */ rec->erh = erh; } /* * exec_eval_using_params --- evaluate params of USING clause * * The result data structure is created in the stmt_mcontext, and should * be freed by resetting that context. */ static ParamListInfo exec_eval_using_params(PLpgSQL_execstate *estate, List *params) { ParamListInfo paramLI; int nargs; MemoryContext stmt_mcontext; MemoryContext oldcontext; int i; ListCell *lc; /* Fast path for no parameters: we can just return NULL */ if (params == NIL) return NULL; nargs = list_length(params); stmt_mcontext = get_stmt_mcontext(estate); oldcontext = MemoryContextSwitchTo(stmt_mcontext); paramLI = makeParamList(nargs); MemoryContextSwitchTo(oldcontext); i = 0; foreach(lc, params) { PLpgSQL_expr *param = (PLpgSQL_expr *) lfirst(lc); ParamExternData *prm = ¶mLI->params[i]; int32 ppdtypmod; /* * Always mark params as const, since we only use the result with * one-shot plans. */ prm->pflags = PARAM_FLAG_CONST; prm->value = exec_eval_expr(estate, param, &prm->isnull, &prm->ptype, &ppdtypmod); oldcontext = MemoryContextSwitchTo(stmt_mcontext); if (prm->ptype == UNKNOWNOID) { /* * Treat 'unknown' parameters as text, since that's what most * people would expect. The SPI functions can coerce unknown * constants in a more intelligent way, but not unknown Params. * This code also takes care of copying into the right context. * Note we assume 'unknown' has the representation of C-string. */ prm->ptype = TEXTOID; if (!prm->isnull) prm->value = CStringGetTextDatum(DatumGetCString(prm->value)); } /* pass-by-ref non null values must be copied into stmt_mcontext */ else if (!prm->isnull) { int16 typLen; bool typByVal; get_typlenbyval(prm->ptype, &typLen, &typByVal); if (!typByVal) prm->value = datumCopy(prm->value, typByVal, typLen); } MemoryContextSwitchTo(oldcontext); exec_eval_cleanup(estate); i++; } return paramLI; } /* * Open portal for dynamic query * * Caution: this resets the stmt_mcontext at exit. We might eventually need * to move that responsibility to the callers, but currently no caller needs * to have statement-lifetime temp data that survives past this, so it's * simpler to do it here. */ static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *dynquery, List *params, const char *portalname, int cursorOptions) { Portal portal; Datum query; bool isnull; Oid restype; int32 restypmod; char *querystr; SPIParseOpenOptions options; MemoryContext stmt_mcontext = get_stmt_mcontext(estate); /* * Evaluate the string expression after the EXECUTE keyword. Its result is * the querystring we have to execute. */ query = exec_eval_expr(estate, dynquery, &isnull, &restype, &restypmod); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(estate, query, restype); /* copy it into the stmt_mcontext before we clean up */ querystr = MemoryContextStrdup(stmt_mcontext, querystr); exec_eval_cleanup(estate); /* * Open an implicit cursor for the query. We use SPI_cursor_parse_open * even when there are no params, because this avoids making and freeing * one copy of the plan. */ memset(&options, 0, sizeof(options)); options.params = exec_eval_using_params(estate, params); options.cursorOptions = cursorOptions; options.read_only = estate->readonly_func; portal = SPI_cursor_parse_open(portalname, querystr, &options); if (portal == NULL) elog(ERROR, "could not open implicit cursor for query \"%s\": %s", querystr, SPI_result_code_string(SPI_result)); /* Release transient data */ MemoryContextReset(stmt_mcontext); return portal; } /* * Return a formatted string with information about an expression's parameters, * or NULL if the expression does not take any parameters. * The result is in the eval_mcontext. */ static char * format_expr_params(PLpgSQL_execstate *estate, const PLpgSQL_expr *expr) { int paramno; int dno; StringInfoData paramstr; MemoryContext oldcontext; if (!expr->paramnos) return NULL; oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); initStringInfo(¶mstr); paramno = 0; dno = -1; while ((dno = bms_next_member(expr->paramnos, dno)) >= 0) { Datum paramdatum; Oid paramtypeid; bool paramisnull; int32 paramtypmod; PLpgSQL_var *curvar; curvar = (PLpgSQL_var *) estate->datums[dno]; exec_eval_datum(estate, (PLpgSQL_datum *) curvar, ¶mtypeid, ¶mtypmod, ¶mdatum, ¶misnull); appendStringInfo(¶mstr, "%s%s = ", paramno > 0 ? ", " : "", curvar->refname); if (paramisnull) appendStringInfoString(¶mstr, "NULL"); else appendStringInfoStringQuoted(¶mstr, convert_value_to_string(estate, paramdatum, paramtypeid), -1); paramno++; } MemoryContextSwitchTo(oldcontext); return paramstr.data; } /* * Return a formatted string with information about the parameter values, * or NULL if there are no parameters. * The result is in the eval_mcontext. */ static char * format_preparedparamsdata(PLpgSQL_execstate *estate, ParamListInfo paramLI) { int paramno; StringInfoData paramstr; MemoryContext oldcontext; if (!paramLI) return NULL; oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); initStringInfo(¶mstr); for (paramno = 0; paramno < paramLI->numParams; paramno++) { ParamExternData *prm = ¶mLI->params[paramno]; /* * Note: for now, this is only used on ParamListInfos produced by * exec_eval_using_params(), so we don't worry about invoking the * paramFetch hook or skipping unused parameters. */ appendStringInfo(¶mstr, "%s$%d = ", paramno > 0 ? ", " : "", paramno + 1); if (prm->isnull) appendStringInfoString(¶mstr, "NULL"); else appendStringInfoStringQuoted(¶mstr, convert_value_to_string(estate, prm->value, prm->ptype), -1); } MemoryContextSwitchTo(oldcontext); return paramstr.data; }