/*------------------------------------------------------------------------- * * pl_exec.c - Executor for the PL/pgSQL * procedural language * * Portions Copyright (c) 1996-2017, 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/htup_details.h" #include "access/transam.h" #include "access/tupconvert.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" #include "executor/spi.h" #include "funcapi.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" #include "optimizer/planner.h" #include "parser/parse_coerce.h" #include "parser/scansup.h" #include "storage/proc.h" #include "tcop/tcopprot.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/typcache.h" #include "plpgsql.h" typedef struct { int nargs; /* number of arguments */ Oid *types; /* types of arguments */ Datum *values; /* evaluated argument values */ char *nulls; /* null markers (' '/'n' style) */ } PreparedParamsData; /* * 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. */ 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; /* * 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 a session-wide hash table for caching cast information. * * Once built, the compiled expression trees (cast_expr fields) survive for * the life of the session. At some point it might be worth invalidating * those after pg_cast changes, but for the moment we don't bother. * * The evaluation state trees (cast_exprstate) 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 hash table but * must have their own. 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_hash table entry */ { plpgsql_CastHashKey key; /* hash key --- MUST BE FIRST */ Expr *cast_expr; /* cast expression, or NULL if no-op cast */ /* 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 MemoryContext shared_cast_context = NULL; static HTAB *shared_cast_hash = NULL; /************************************************************ * Local function forward declarations ************************************************************/ static void plpgsql_exec_error_callback(void *arg); static PLpgSQL_datum *copy_plpgsql_datum(PLpgSQL_datum *datum); 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_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block); static int exec_stmts(PLpgSQL_execstate *estate, List *stmts); static int exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt); 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_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 void plpgsql_estate_setup(PLpgSQL_execstate *estate, PLpgSQL_function *func, ReturnSetInfo *rsi, EState *simple_eval_estate); 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, int target_dno); static bool contains_target_param(Node *node, int *target_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 ParamListInfo setup_unshared_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr); static void plpgsql_param_fetch(ParamListInfo params, int paramid); static void exec_move_row(PLpgSQL_execstate *estate, PLpgSQL_variable *target, HeapTuple tup, TupleDesc tupdesc); static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate, PLpgSQL_row *row, TupleDesc tupdesc); static HeapTuple get_tuple_from_datum(Datum value); static TupleDesc get_tupdesc_from_datum(Datum value); static void exec_move_row_from_datum(PLpgSQL_execstate *estate, PLpgSQL_variable *target, Datum value); static char *convert_value_to_string(PLpgSQL_execstate *estate, Datum value, Oid valtype); static Datum exec_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 PreparedParamsData *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, const PreparedParamsData *ppd); /* ---------- * 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, which is created and passed in by * the caller. For regular functions, pass NULL, which implies using * shared_simple_eval_estate. (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.) * ---------- */ Datum plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo, EState *simple_eval_estate) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int i; int rc; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo, simple_eval_estate); /* * 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"); for (i = 0; i < estate.ndatums; i++) estate.datums[i] = copy_plpgsql_datum(func->datums[i]); /* * 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->arg[i], fcinfo->argnull[i], 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, CurrentMemoryContext), 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, CurrentMemoryContext, NULL), false, true); } } } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) estate.datums[n]; if (!fcinfo->argnull[i]) { /* Assign row value from composite datum */ exec_move_row_from_datum(&estate, (PLpgSQL_variable *) row, fcinfo->arg[i]); } else { /* If arg is null, treat it as an empty row */ exec_move_row(&estate, (PLpgSQL_variable *) row, NULL, NULL); } /* clean up after exec_move_row() */ exec_eval_cleanup(&estate); } break; default: 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; estate.err_stmt = (PLpgSQL_stmt *) (func->action); rc = exec_stmt_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN && func->fn_rettype) { estate.err_stmt = NULL; 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_stmt = NULL; 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) || (rsi->allowedModes & SFRM_Materialize) == 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); rsi->returnMode = SFRM_Materialize; /* If we produced any tuples, send back the result */ if (estate.tuple_store) { rsi->setResult = estate.tuple_store; if (estate.rettupdesc) { MemoryContext oldcxt; oldcxt = MemoryContextSwitchTo(estate.tuple_store_cxt); rsi->setDesc = CreateTupleDescCopy(estate.rettupdesc); MemoryContextSwitchTo(oldcxt); } } estate.retval = (Datum) 0; fcinfo->isnull = true; } else if (!estate.retisnull) { if (!func->fn_rettype) { ereport(ERROR, (errmsg("cannot return a value from a procedure"))); } if (estate.retistuple) { /* * We have to check that the returned tuple actually matches the * expected result type. XXX would be better to cache the tupdesc * instead of repeating get_call_result_type() */ HeapTuple rettup = (HeapTuple) DatumGetPointer(estate.retval); TupleDesc tupdesc; TupleConversionMap *tupmap; switch (get_call_result_type(fcinfo, NULL, &tupdesc)) { case TYPEFUNC_COMPOSITE: /* got the expected result rowtype, now check it */ tupmap = convert_tuples_by_position(estate.rettupdesc, tupdesc, gettext_noop("returned record type does not match expected record type")); /* it might need conversion */ if (tupmap) rettup = do_convert_tuple(rettup, tupmap); /* no need to free map, we're about to return anyway */ 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 type, instead. */ tupdesc = estate.rettupdesc; if (tupdesc == NULL) /* shouldn't happen */ elog(ERROR, "return type must be a row type"); break; default: /* shouldn't get here if retistuple is true ... */ elog(ERROR, "return type must be a row type"); break; } /* * 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)); } else { /* Cast value to proper type */ 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); } } 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; } /* ---------- * 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 i; int rc; PLpgSQL_var *var; PLpgSQL_rec *rec_new, *rec_old; HeapTuple rettup; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, NULL, NULL); /* * 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"); for (i = 0; i < estate.ndatums; i++) estate.datums[i] = copy_plpgsql_datum(func->datums[i]); /* * Put the OLD and NEW tuples into record variables * * We make the tupdescs available in both records even though only one may * have a value. This allows parsing of 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 parse regardless of the current trigger type. */ rec_new = (PLpgSQL_rec *) (estate.datums[func->new_varno]); rec_new->freetup = false; rec_new->tupdesc = trigdata->tg_relation->rd_att; rec_new->freetupdesc = false; rec_old = (PLpgSQL_rec *) (estate.datums[func->old_varno]); rec_old->freetup = false; rec_old->tupdesc = trigdata->tg_relation->rd_att; rec_old->freetupdesc = false; if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) { /* * Per-statement triggers don't use OLD/NEW variables */ rec_new->tup = NULL; rec_old->tup = NULL; } else if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) { rec_new->tup = trigdata->tg_trigtuple; rec_old->tup = NULL; } else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) { rec_new->tup = trigdata->tg_newtuple; rec_old->tup = trigdata->tg_trigtuple; } else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) { rec_new->tup = NULL; rec_old->tup = trigdata->tg_trigtuple; } 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); /* * Assign the special tg_ variables */ var = (PLpgSQL_var *) (estate.datums[func->tg_op_varno]); if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) assign_text_var(&estate, var, "INSERT"); else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) assign_text_var(&estate, var, "UPDATE"); else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) assign_text_var(&estate, var, "DELETE"); else if (TRIGGER_FIRED_BY_TRUNCATE(trigdata->tg_event)) assign_text_var(&estate, var, "TRUNCATE"); else elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, UPDATE, or TRUNCATE"); var = (PLpgSQL_var *) (estate.datums[func->tg_name_varno]); assign_simple_var(&estate, var, DirectFunctionCall1(namein, CStringGetDatum(trigdata->tg_trigger->tgname)), false, true); var = (PLpgSQL_var *) (estate.datums[func->tg_when_varno]); if (TRIGGER_FIRED_BEFORE(trigdata->tg_event)) assign_text_var(&estate, var, "BEFORE"); else if (TRIGGER_FIRED_AFTER(trigdata->tg_event)) assign_text_var(&estate, var, "AFTER"); else if (TRIGGER_FIRED_INSTEAD(trigdata->tg_event)) assign_text_var(&estate, var, "INSTEAD OF"); else elog(ERROR, "unrecognized trigger execution time: not BEFORE, AFTER, or INSTEAD OF"); var = (PLpgSQL_var *) (estate.datums[func->tg_level_varno]); if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) assign_text_var(&estate, var, "ROW"); else if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event)) assign_text_var(&estate, var, "STATEMENT"); else elog(ERROR, "unrecognized trigger event type: not ROW or STATEMENT"); var = (PLpgSQL_var *) (estate.datums[func->tg_relid_varno]); assign_simple_var(&estate, var, ObjectIdGetDatum(trigdata->tg_relation->rd_id), false, false); var = (PLpgSQL_var *) (estate.datums[func->tg_relname_varno]); assign_simple_var(&estate, var, DirectFunctionCall1(namein, CStringGetDatum(RelationGetRelationName(trigdata->tg_relation))), false, true); var = (PLpgSQL_var *) (estate.datums[func->tg_table_name_varno]); assign_simple_var(&estate, var, DirectFunctionCall1(namein, CStringGetDatum(RelationGetRelationName(trigdata->tg_relation))), false, true); var = (PLpgSQL_var *) (estate.datums[func->tg_table_schema_varno]); assign_simple_var(&estate, var, DirectFunctionCall1(namein, CStringGetDatum(get_namespace_name( RelationGetNamespace( trigdata->tg_relation)))), false, true); var = (PLpgSQL_var *) (estate.datums[func->tg_nargs_varno]); assign_simple_var(&estate, var, Int16GetDatum(trigdata->tg_trigger->tgnargs), false, false); var = (PLpgSQL_var *) (estate.datums[func->tg_argv_varno]); if (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 = trigdata->tg_trigger->tgnargs; Datum *elems; int dims[1]; int lbs[1]; elems = palloc(sizeof(Datum) * nelems); for (i = 0; i < nelems; i++) elems[i] = CStringGetTextDatum(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, 'i')), false, true); } else { assign_simple_var(&estate, var, (Datum) 0, true, false); } 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; estate.err_stmt = (PLpgSQL_stmt *) (func->action); rc = exec_stmt_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_stmt = NULL; 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_stmt = NULL; 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 { TupleConversionMap *tupmap; rettup = (HeapTuple) DatumGetPointer(estate.retval); /* check rowtype compatibility */ tupmap = convert_tuples_by_position(estate.rettupdesc, trigdata->tg_relation->rd_att, gettext_noop("returned row structure does not match the structure of the triggering table")); /* it might need conversion */ if (tupmap) rettup = do_convert_tuple(rettup, tupmap); /* 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 i; int rc; PLpgSQL_var *var; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, NULL, NULL); /* * 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"); for (i = 0; i < estate.ndatums; i++) estate.datums[i] = copy_plpgsql_datum(func->datums[i]); /* * Assign the special tg_ variables */ var = (PLpgSQL_var *) (estate.datums[func->tg_event_varno]); assign_text_var(&estate, var, trigdata->event); var = (PLpgSQL_var *) (estate.datums[func->tg_tag_varno]); assign_text_var(&estate, var, trigdata->tag); /* * 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; estate.err_stmt = (PLpgSQL_stmt *) (func->action); rc = exec_stmt_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_stmt = NULL; 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_stmt = NULL; 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; } /* * 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; 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 both err_text and err_stmt are set, use the err_text as * description, but 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_stmt != NULL) { /* * 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, estate->err_stmt->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) { /* translator: last %s is a plpgsql statement type name */ errcontext("PL/pgSQL function %s line %d at %s", estate->func->fn_signature, estate->err_stmt->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 PLpgSQL_datum * copy_plpgsql_datum(PLpgSQL_datum *datum) { PLpgSQL_datum *result; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *new = palloc(sizeof(PLpgSQL_var)); memcpy(new, datum, sizeof(PLpgSQL_var)); /* should be preset to null/non-freeable */ Assert(new->isnull); Assert(!new->freeval); result = (PLpgSQL_datum *) new; } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *new = palloc(sizeof(PLpgSQL_rec)); memcpy(new, datum, sizeof(PLpgSQL_rec)); /* should be preset to null/non-freeable */ Assert(new->tup == NULL); Assert(new->tupdesc == NULL); Assert(!new->freetup); Assert(!new->freetupdesc); result = (PLpgSQL_datum *) new; } break; case PLPGSQL_DTYPE_ROW: case PLPGSQL_DTYPE_RECFIELD: case PLPGSQL_DTYPE_ARRAYELEM: /* * These datum records are read-only at runtime, so no need to * copy them (well, ARRAYELEM contains some cached type data, but * we'd just as soon centralize the caching anyway) */ result = datum; break; default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); result = NULL; /* keep compiler quiet */ break; } return result; } /* * 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_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; int n; /* * 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++) { n = block->initvarnos[i]; switch (estate->datums[n]->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) (estate->datums[n]); /* * 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. (Do this * before the notnull check to be consistent with * exec_assign_value.) */ if (var->datatype->typtype == TYPTYPE_DOMAIN) exec_assign_value(estate, (PLpgSQL_datum *) var, (Datum) 0, true, UNKNOWNOID, -1); if (var->notnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("variable \"%s\" declared NOT NULL cannot default to NULL", var->refname))); } else { exec_assign_expr(estate, (PLpgSQL_datum *) var, var->default_val); } } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) (estate->datums[n]); if (rec->freetup) { heap_freetuple(rec->tup); rec->freetup = false; } if (rec->freetupdesc) { FreeTupleDesc(rec->tupdesc); rec->freetupdesc = false; } rec->tup = NULL; rec->tupdesc = NULL; } break; case PLPGSQL_DTYPE_RECFIELD: case PLPGSQL_DTYPE_ARRAYELEM: break; default: elog(ERROR, "unrecognized dtype: %d", estate->datums[n]->dtype); } } 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. This is * currently only needed for scalar result types --- rowtype * values will always exist in the function's main memory context, * cf. exec_stmt_return(). 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 && estate->rettupdesc == NULL) { 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. */ switch (rc) { case PLPGSQL_RC_OK: case PLPGSQL_RC_RETURN: case PLPGSQL_RC_CONTINUE: return rc; case PLPGSQL_RC_EXIT: /* * This is intentionally different from the handling of RC_EXIT * for loops: to match a block, we require a match by label. */ 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) { 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 = exec_stmt(estate, stmt); if (rc != PLPGSQL_RC_OK) return rc; } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt Distribute one statement to the statements * type specific execution function. * ---------- */ static int exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt) { PLpgSQL_stmt *save_estmt; int rc = -1; save_estmt = estate->err_stmt; 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_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; default: estate->err_stmt = save_estmt; elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type); } /* 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); estate->err_stmt = save_estmt; return rc; } /* ---------- * 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_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_RESULT_OID: exec_assign_value(estate, var, ObjectIdGetDatum(estate->eval_lastoid), 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); /* 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) { for (;;) { int rc = exec_stmts(estate, stmt->body); switch (rc) { case PLPGSQL_RC_OK: break; case PLPGSQL_RC_EXIT: if (estate->exitlabel == NULL) return PLPGSQL_RC_OK; if (stmt->label == NULL) return PLPGSQL_RC_EXIT; if (strcmp(stmt->label, estate->exitlabel) != 0) return PLPGSQL_RC_EXIT; estate->exitlabel = NULL; return PLPGSQL_RC_OK; case PLPGSQL_RC_CONTINUE: if (estate->exitlabel == NULL) /* anonymous continue, so re-run the loop */ break; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) /* label matches named continue, so re-run loop */ estate->exitlabel = NULL; else /* label doesn't match named continue, so propagate upward */ return PLPGSQL_RC_CONTINUE; break; case PLPGSQL_RC_RETURN: return rc; default: elog(ERROR, "unrecognized rc: %d", 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) { for (;;) { int rc; 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); switch (rc) { case PLPGSQL_RC_OK: break; case PLPGSQL_RC_EXIT: if (estate->exitlabel == NULL) return PLPGSQL_RC_OK; if (stmt->label == NULL) return PLPGSQL_RC_EXIT; if (strcmp(stmt->label, estate->exitlabel) != 0) return PLPGSQL_RC_EXIT; estate->exitlabel = NULL; return PLPGSQL_RC_OK; case PLPGSQL_RC_CONTINUE: if (estate->exitlabel == NULL) /* anonymous continue, so re-run loop */ break; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) /* label matches named continue, so re-run loop */ estate->exitlabel = NULL; else /* label doesn't match named continue, propagate upward */ return PLPGSQL_RC_CONTINUE; break; case PLPGSQL_RC_RETURN: return rc; default: elog(ERROR, "unrecognized rc: %d", rc); } } return PLPGSQL_RC_OK; } /* ---------- * 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); if (rc == PLPGSQL_RC_RETURN) break; /* break out of the loop */ else if (rc == PLPGSQL_RC_EXIT) { if (estate->exitlabel == NULL) /* unlabelled exit, finish the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* labelled exit, matches the current stmt's label */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } /* * otherwise, this is a labelled exit that does not match the * current statement's label, if any: return RC_EXIT so that the * EXIT continues to propagate up the stack. */ break; } else if (rc == PLPGSQL_RC_CONTINUE) { if (estate->exitlabel == NULL) /* unlabelled continue, so re-run the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches named continue, so re-run loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } else { /* * otherwise, this is a named continue that does not match the * current statement's label, if any: return RC_CONTINUE so * that the CONTINUE will propagate up the stack. */ break; } } /* * Increase/decrease loop value, unless it would overflow, in which * case exit the loop. */ if (stmt->reverse) { if ((int32) (loop_value - step_value) > loop_value) break; loop_value -= step_value; } else { if ((int32) (loop_value + step_value) < loop_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 short-lived ParamListInfo */ paramLI = setup_unshared_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 */ if (curname == NULL) 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); /* Handle the return code */ if (rc == PLPGSQL_RC_RETURN) break; /* break out of the loop */ else if (rc == PLPGSQL_RC_EXIT) { if (estate->exitlabel == NULL) /* unlabelled exit, finish the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* labelled exit, matches the current stmt's label */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } /* * otherwise, this is a labelled exit that does not match the * current statement's label, if any: return RC_EXIT so that the * EXIT continues to propagate up the stack. */ break; } else if (rc == PLPGSQL_RC_CONTINUE) { if (estate->exitlabel == NULL) /* unlabelled continue, so re-run the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches named continue, so re-run loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } else { /* * otherwise, this is a named continue that does not match the * current statement's label, if any: return RC_CONTINUE so * that the CONTINUE will propagate up the stack. */ 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: in the retistuple code paths, the returned tuple is always in the * function's main context, whereas for non-tuple data types the result may * be in the eval_mcontext. The former case is not a memory leak since we're * about to exit the function anyway. (If you want to change it, note that * exec_stmt_block() knows about this behavior.) The latter case means that * 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 (possibly a tuple) */ estate->retval = (Datum) 0; estate->rettupdesc = NULL; 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_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) retvar; estate->retval = var->value; estate->retisnull = var->isnull; estate->rettype = var->datatype->typoid; /* * Cope with retistuple case. A PLpgSQL_var could not be * of composite type, so we needn't make any effort to * convert. However, for consistency with the expression * code path, don't throw error if the result is NULL. */ 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; int32 rettypmod; if (HeapTupleIsValid(rec->tup)) { if (estate->retistuple) { estate->retval = PointerGetDatum(rec->tup); estate->rettupdesc = rec->tupdesc; estate->retisnull = false; } else exec_eval_datum(estate, retvar, &estate->rettype, &rettypmod, &estate->retval, &estate->retisnull); } } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; int32 rettypmod; if (estate->retistuple) { HeapTuple tup; if (!row->rowtupdesc) /* should not happen */ elog(ERROR, "row variable has no tupdesc"); tup = make_tuple_from_row(estate, row, row->rowtupdesc); if (tup == NULL) /* should not happen */ elog(ERROR, "row not compatible with its own tupdesc"); estate->retval = PointerGetDatum(tup); estate->rettupdesc = row->rowtupdesc; estate->retisnull = false; } else exec_eval_datum(estate, retvar, &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); if (estate->retistuple && !estate->retisnull) { /* Convert composite datum to a HeapTuple and TupleDesc */ HeapTuple tuple; TupleDesc tupdesc; /* Source must be of RECORD or composite type */ if (!type_is_rowtype(estate->rettype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot return non-composite value from function returning composite type"))); tuple = get_tuple_from_datum(estate->retval); tupdesc = get_tupdesc_from_datum(estate->retval); estate->retval = PointerGetDatum(tuple); estate->rettupdesc = CreateTupleDescCopy(tupdesc); ReleaseTupleDesc(tupdesc); } 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. */ if (estate->fn_rettype == VOIDOID) { 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); /* rettupdesc will be filled by exec_init_tuple_store */ tupdesc = estate->rettupdesc; 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_statement_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_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; TupleConversionMap *tupmap; if (!HeapTupleIsValid(rec->tup)) 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."))); /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); tupmap = convert_tuples_by_position(rec->tupdesc, tupdesc, gettext_noop("wrong record type supplied in RETURN NEXT")); tuple = rec->tup; if (tupmap) tuple = do_convert_tuple(tuple, tupmap); tuplestore_puttuple(estate->tuple_store, tuple); MemoryContextSwitchTo(oldcontext); } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); tuple = make_tuple_from_row(estate, row, tupdesc); if (tuple == NULL) 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) { 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)); tuple = get_tuple_from_datum(retval); retvaldesc = get_tupdesc_from_datum(retval); tupmap = convert_tuples_by_position(retvaldesc, tupdesc, gettext_noop("returned record type does not match expected record type")); if (tupmap) tuple = do_convert_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) { Portal portal; uint64 processed = 0; TupleConversionMap *tupmap; 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); if (stmt->query != NULL) { /* static query */ exec_run_select(estate, stmt->query, 0, &portal); } else { /* RETURN QUERY EXECUTE */ Assert(stmt->dynquery != NULL); portal = exec_dynquery_with_params(estate, stmt->dynquery, stmt->params, NULL, 0); } /* Use eval_mcontext for tuple conversion work */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); tupmap = convert_tuples_by_position(portal->tupDesc, estate->rettupdesc, gettext_noop("structure of query does not match function result type")); while (true) { uint64 i; SPI_cursor_fetch(portal, true, 50); /* SPI will have changed CurrentMemoryContext */ MemoryContextSwitchTo(get_eval_mcontext(estate)); if (SPI_processed == 0) break; for (i = 0; i < SPI_processed; i++) { HeapTuple tuple = SPI_tuptable->vals[i]; if (tupmap) tuple = do_convert_tuple(tuple, tupmap); tuplestore_puttuple(estate->tuple_store, tuple); if (tupmap) heap_freetuple(tuple); processed++; } SPI_freetuptable(SPI_tuptable); } SPI_freetuptable(SPI_tuptable); SPI_cursor_close(portal); MemoryContextSwitchTo(oldcontext); exec_eval_cleanup(estate); 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) || (rsi->allowedModes & SFRM_Materialize) == 0 || rsi->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); /* * 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->rettupdesc = 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(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) { HASHCTL ctl; /* this link will be restored at exit from plpgsql_call_handler */ func->cur_estate = estate; estate->func = func; 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->rettupdesc = NULL; estate->exitlabel = NULL; estate->cur_error = NULL; estate->tuple_store = 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 = palloc(sizeof(PLpgSQL_datum *) * estate->ndatums); /* caller is expected to fill the datums array */ /* initialize ParamListInfo with one entry per datum, all invalid */ estate->paramLI = (ParamListInfo) palloc0(offsetof(ParamListInfoData, params) + estate->ndatums * sizeof(ParamExternData)); estate->paramLI->paramFetch = plpgsql_param_fetch; estate->paramLI->paramFetchArg = (void *) estate; estate->paramLI->parserSetup = (ParserSetupHook) plpgsql_parser_setup; estate->paramLI->parserSetupArg = NULL; /* filled during use */ estate->paramLI->numParams = estate->ndatums; estate->paramLI->paramMask = NULL; estate->params_dirty = false; /* 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 */ memset(&ctl, 0, sizeof(ctl)); 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); estate->cast_hash_context = CurrentMemoryContext; } 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) { shared_cast_context = AllocSetContextCreate(TopMemoryContext, "PLpgSQL cast info", ALLOCSET_DEFAULT_SIZES); memset(&ctl, 0, sizeof(ctl)); ctl.keysize = sizeof(plpgsql_CastHashKey); ctl.entrysize = sizeof(plpgsql_CastHashEntry); ctl.hcxt = shared_cast_context; shared_cast_hash = hash_create("PLpgSQL cast cache", 16, /* start small and extend */ &ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); } estate->cast_hash = shared_cast_hash; estate->cast_hash_context = shared_cast_context; } /* * 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_lastoid = InvalidOid; estate->eval_econtext = NULL; estate->err_stmt = 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 see this function before we initialize any 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; 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. * * NB: if you change this code, see also the hacks in exec_assign_value's * PLPGSQL_DTYPE_ARRAYELEM case for partial cleanup after subscript evals. * ---------- */ 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 * ---------- */ static void exec_prepare_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, int cursorOptions) { SPIPlanPtr plan; /* * 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 */ plan = SPI_prepare_params(expr->query, (ParserSetupHook) plpgsql_parser_setup, (void *) expr, cursorOptions); if (plan == NULL) { /* Some SPI errors deserve specific error messages */ switch (SPI_result) { case SPI_ERROR_COPY: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot COPY to/from client in PL/pgSQL"))); case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot begin/end transactions in PL/pgSQL"), errhint("Use a BEGIN block with an EXCEPTION clause instead."))); default: elog(ERROR, "SPI_prepare_params 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); /* * Mark expression as not using a read-write param. exec_assign_value has * to take steps to override this if appropriate; that seems cleaner than * adding parameters to all other callers. */ expr->rwparam = -1; } /* ---------- * 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; /* * On the first call for this statement generate the plan, and detect * whether the statement is INSERT/UPDATE/DELETE */ if (expr->plan == NULL) { ListCell *l; exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK); stmt->mod_stmt = false; foreach(l, SPI_plan_get_plan_sources(expr->plan)) { CachedPlanSource *plansource = (CachedPlanSource *) lfirst(l); ListCell *l2; foreach(l2, plansource->query_list) { Query *q = lfirst_node(Query, l2); if (q->canSetTag) { if (q->commandType == CMD_INSERT || q->commandType == CMD_UPDATE || q->commandType == CMD_DELETE) stmt->mod_stmt = 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, 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) 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: 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: Assert(!stmt->mod_stmt); /* * 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. */ 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"))); case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot begin/end transactions in PL/pgSQL"), errhint("Use a BEGIN block with an EXCEPTION clause instead."))); default: elog(ERROR, "SPI_execute_plan_with_paramlist failed executing query \"%s\": %s", expr->query, SPI_result_code_string(rc)); } /* All variants should save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; /* 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)) { char *errdetail; if (estate->func->print_strict_params) errdetail = format_expr_params(estate, expr); 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 */ 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; PreparedParamsData *ppd = NULL; 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. */ if (stmt->params) { ppd = exec_eval_using_params(estate, stmt->params); exec_res = SPI_execute_with_args(querystr, ppd->nargs, ppd->types, ppd->values, ppd->nulls, estate->readonly_func, 0); } else exec_res = SPI_execute(querystr, estate->readonly_func, 0); 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_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"))); case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot begin/end transactions in PL/pgSQL"), errhint("Use a BEGIN block with an EXCEPTION clause instead."))); default: elog(ERROR, "SPI_execute failed executing query \"%s\": %s", querystr, SPI_result_code_string(exec_res)); break; } /* Save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; /* 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, ppd); 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, ppd); 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, 0); /* * 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. * 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) 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 short-lived ParamListInfo */ paramLI = setup_unshared_param_list(estate, query); /* * Open the cursor */ 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 */ if (curname == NULL) 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_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, and then see * if we can pass the target variable as a read-write parameter to the * expression. (This is a bit messy, but it seems cleaner than modifying * the API of exec_eval_expr for the purpose.) */ if (expr->plan == NULL) { exec_prepare_plan(estate, expr, 0); if (target->dtype == PLPGSQL_DTYPE_VAR) exec_check_rw_parameter(expr, target->dno); } 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: { /* * 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, CurrentMemoryContext, 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. */ if (var->value != newvalue || var->isnull || isNull) assign_simple_var(estate, var, newvalue, isNull, (!var->datatype->typbyval && !isNull)); 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 source is null, just assign nulls to the record */ 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; int fno; HeapTuple newtup; int colnums[1]; Datum values[1]; bool nulls[1]; Oid atttype; int32 atttypmod; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); /* * Check that there is already a tuple in the record. We need * that because records don't have any predefined field * structure. */ if (!HeapTupleIsValid(rec->tup)) 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."))); /* * Get the number of the record field to change. Disallow * system columns because the code below won't cope. */ fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno <= 0) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); colnums[0] = fno; /* * Now insert the new value, being careful to cast it to the * right type. */ atttype = TupleDescAttr(rec->tupdesc, fno - 1)->atttypid; atttypmod = TupleDescAttr(rec->tupdesc, fno - 1)->atttypmod; values[0] = exec_cast_value(estate, value, &isNull, valtype, valtypmod, atttype, atttypmod); nulls[0] = isNull; newtup = heap_modify_tuple_by_cols(rec->tup, rec->tupdesc, 1, colnums, values, nulls); if (rec->freetup) heap_freetuple(rec->tup); rec->tup = newtup; rec->freetup = true; break; } case PLPGSQL_DTYPE_ARRAYELEM: { /* * Target is an element of an array */ PLpgSQL_arrayelem *arrayelem; int nsubscripts; int i; PLpgSQL_expr *subscripts[MAXDIM]; int subscriptvals[MAXDIM]; Datum oldarraydatum, newarraydatum, coerced_value; bool oldarrayisnull; Oid parenttypoid; int32 parenttypmod; SPITupleTable *save_eval_tuptable; MemoryContext oldcontext; /* * We need to do subscript evaluation, which might require * evaluating general expressions; and the caller might have * done that too in order to prepare the input Datum. We have * to save and restore the caller's SPI_execute result, if * any. */ save_eval_tuptable = estate->eval_tuptable; estate->eval_tuptable = NULL; /* * To handle constructs like x[1][2] := something, we have to * be prepared to deal with a chain of arrayelem datums. Chase * back to find the base array datum, and save the subscript * expressions as we go. (We are scanning right to left here, * but want to evaluate the subscripts left-to-right to * minimize surprises.) Note that arrayelem is left pointing * to the leftmost arrayelem datum, where we will cache the * array element type data. */ nsubscripts = 0; do { arrayelem = (PLpgSQL_arrayelem *) target; if (nsubscripts >= MAXDIM) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)", nsubscripts + 1, MAXDIM))); subscripts[nsubscripts++] = arrayelem->subscript; target = estate->datums[arrayelem->arrayparentno]; } while (target->dtype == PLPGSQL_DTYPE_ARRAYELEM); /* Fetch current value of array datum */ exec_eval_datum(estate, target, &parenttypoid, &parenttypmod, &oldarraydatum, &oldarrayisnull); /* Update cached type data if necessary */ if (arrayelem->parenttypoid != parenttypoid || arrayelem->parenttypmod != parenttypmod) { Oid arraytypoid; int32 arraytypmod = parenttypmod; int16 arraytyplen; Oid elemtypoid; int16 elemtyplen; bool elemtypbyval; char elemtypalign; /* If target is domain over array, reduce to base type */ arraytypoid = getBaseTypeAndTypmod(parenttypoid, &arraytypmod); /* ... and identify the element type */ elemtypoid = get_element_type(arraytypoid); if (!OidIsValid(elemtypoid)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("subscripted object is not an array"))); /* Collect needed data about the types */ arraytyplen = get_typlen(arraytypoid); get_typlenbyvalalign(elemtypoid, &elemtyplen, &elemtypbyval, &elemtypalign); /* Now safe to update the cached data */ arrayelem->parenttypoid = parenttypoid; arrayelem->parenttypmod = parenttypmod; arrayelem->arraytypoid = arraytypoid; arrayelem->arraytypmod = arraytypmod; arrayelem->arraytyplen = arraytyplen; arrayelem->elemtypoid = elemtypoid; arrayelem->elemtyplen = elemtyplen; arrayelem->elemtypbyval = elemtypbyval; arrayelem->elemtypalign = elemtypalign; } /* * Evaluate the subscripts, switch into left-to-right order. * Like the expression built by ExecInitArrayRef(), complain * if any subscript is null. */ for (i = 0; i < nsubscripts; i++) { bool subisnull; subscriptvals[i] = exec_eval_integer(estate, subscripts[nsubscripts - 1 - i], &subisnull); if (subisnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("array subscript in assignment must not be null"))); /* * Clean up in case the subscript expression wasn't * simple. We can't do exec_eval_cleanup, but we can do * this much (which is safe because the integer subscript * value is surely pass-by-value), and we must do it in * case the next subscript expression isn't simple either. */ if (estate->eval_tuptable != NULL) SPI_freetuptable(estate->eval_tuptable); estate->eval_tuptable = NULL; } /* Now we can restore caller's SPI_execute result if any. */ Assert(estate->eval_tuptable == NULL); estate->eval_tuptable = save_eval_tuptable; /* Coerce source value to match array element type. */ coerced_value = exec_cast_value(estate, value, &isNull, valtype, valtypmod, arrayelem->elemtypoid, arrayelem->arraytypmod); /* * If the original array is null, cons up an empty array so * that the assignment can proceed; we'll end with a * one-element array containing just the assigned-to * subscript. This only works for varlena arrays, though; for * fixed-length array types we skip the assignment. We can't * support assignment of a null entry into a fixed-length * array, either, so that's a no-op too. This is all ugly but * corresponds to the current behavior of execExpr*.c. */ if (arrayelem->arraytyplen > 0 && /* fixed-length array? */ (oldarrayisnull || isNull)) return; /* empty array, if any, and newarraydatum are short-lived */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); if (oldarrayisnull) oldarraydatum = PointerGetDatum(construct_empty_array(arrayelem->elemtypoid)); /* * Build the modified array value. */ newarraydatum = array_set_element(oldarraydatum, nsubscripts, subscriptvals, coerced_value, isNull, arrayelem->arraytyplen, arrayelem->elemtyplen, arrayelem->elemtypbyval, arrayelem->elemtypalign); MemoryContextSwitchTo(oldcontext); /* * Assign the new array to the base variable. It's never NULL * at this point. Note that if the target is a domain, * coercing the base array type back up to the domain will * happen within exec_assign_value. */ exec_assign_value(estate, target, newarraydatum, false, arrayelem->arraytypoid, arrayelem->arraytypmod); 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 or PLpgSQL_arrayelem 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_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; 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 (!HeapTupleIsValid(rec->tup)) 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."))); Assert(rec->tupdesc != NULL); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(rec->tupdesc); oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); *typeid = rec->tupdesc->tdtypeid; *typetypmod = rec->tupdesc->tdtypmod; *value = heap_copy_tuple_as_datum(rec->tup, rec->tupdesc); *isnull = false; MemoryContextSwitchTo(oldcontext); break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; int fno; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); if (!HeapTupleIsValid(rec->tup)) 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."))); fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); *typeid = SPI_gettypeid(rec->tupdesc, fno); if (fno > 0) { Form_pg_attribute attr = TupleDescAttr(rec->tupdesc, fno - 1); *typetypmod = attr->atttypmod; } else *typetypmod = -1; *value = SPI_getbinval(rec->tup, rec->tupdesc, fno, 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, except that it can handle * some cases where exec_eval_datum has to fail; specifically, we may have * a tupdesc but no row value for a record variable. (This currently can * happen only for a trigger's NEW/OLD records.) */ Oid plpgsql_exec_get_datum_type(PLpgSQL_execstate *estate, PLpgSQL_datum *datum) { Oid typeid; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) datum; typeid = var->datatype->typoid; break; } case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) datum; 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); typeid = row->rowtupdesc->tdtypeid; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->tupdesc == NULL) 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 we have a valid type/typmod setting */ BlessTupleDesc(rec->tupdesc); typeid = rec->tupdesc->tdtypeid; break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; int fno; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); if (rec->tupdesc == NULL) 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."))); fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); typeid = SPI_gettypeid(rec->tupdesc, fno); 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. */ 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: { PLpgSQL_var *var = (PLpgSQL_var *) datum; *typeid = var->datatype->typoid; *typmod = var->datatype->atttypmod; *collation = var->datatype->collation; break; } case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) datum; 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); *typeid = row->rowtupdesc->tdtypeid; /* do NOT return the mutable typmod of a RECORD variable */ *typmod = -1; /* composite types are never collatable */ *collation = InvalidOid; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->tupdesc == NULL) 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 we have a valid type/typmod setting */ BlessTupleDesc(rec->tupdesc); *typeid = rec->tupdesc->tdtypeid; /* 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; int fno; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); if (rec->tupdesc == NULL) 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."))); fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); *typeid = SPI_gettypeid(rec->tupdesc, fno); if (fno > 0) { Form_pg_attribute attr = TupleDescAttr(rec->tupdesc, fno - 1); *typmod = attr->atttypmod; } else *typmod = -1; if (fno > 0) { Form_pg_attribute attr = TupleDescAttr(rec->tupdesc, fno - 1); *collation = attr->attcollation; } else /* no system column types have collation */ *collation = InvalidOid; 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 \"%s\" did not return data", 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 \"%s\" returned %d column", "query \"%s\" returned %d columns", estate->eval_tuptable->tupdesc->natts, expr->query, estate->eval_tuptable->tupdesc->natts))); /* * ... 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 \"%s\" returned more than one row", 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 once, 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, the caller might do cursor operations, which parallel query * can't support. */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, portalP == NULL ? CURSOR_OPT_PARALLEL_OK : 0); /* * If a portal was requested, put the query into the portal */ if (portalP != NULL) { /* * Set up short-lived ParamListInfo */ paramLI = setup_unshared_param_list(estate, expr); *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; } /* * Set up ParamListInfo to pass to executor */ paramLI = setup_param_list(estate, expr); /* * Execute the query */ rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI, estate->readonly_func, maxtuples); if (rc != SPI_OK_SELECT) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query \"%s\" is not a SELECT", expr->query))); /* Save query results for eventual cleanup */ Assert(estate->eval_tuptable == NULL); estate->eval_tuptable = SPI_tuptable; estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; 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 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); /* * 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 */ exec_move_row(estate, var, tuptab->vals[i], tuptab->tupdesc); exec_eval_cleanup(estate); /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); if (rc != PLPGSQL_RC_OK) { if (rc == PLPGSQL_RC_EXIT) { if (estate->exitlabel == NULL) { /* unlabelled exit, so exit the current loop */ rc = PLPGSQL_RC_OK; } else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches this loop, so exit loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } /* * otherwise, we processed a labelled exit that does not * match the current statement's label, if any; return * RC_EXIT so that the EXIT continues to recurse upward. */ } else if (rc == PLPGSQL_RC_CONTINUE) { if (estate->exitlabel == NULL) { /* unlabelled continue, so re-run the current loop */ rc = PLPGSQL_RC_OK; continue; } else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches this loop, so re-run loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; continue; } /* * otherwise, we process a labelled continue that does not * match the current statement's label, if any; return * RC_CONTINUE so that the CONTINUE will propagate up the * stack. */ } /* * We're aborting the loop. Need a goto to get out of two * levels of loop... */ 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. * Fortunately it's normally inexpensive to call SPI_plan_get_cached_plan for * a simple expression. * * 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; CachedPlan *cplan; ParamListInfo paramLI; void *save_setup_arg; 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 (expr->expr_simple_in_use && expr->expr_simple_lxid == curlxid) return false; /* * Revalidate cached plan, so that we will notice if it became stale. (We * need to hold a refcount while using the plan, anyway.) If replanning * is needed, do that 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); /* If it got replanned, update our copy of the simple expression */ if (cplan->generation != expr->expr_simple_generation) { exec_save_simple_expr(expr, cplan); /* better recheck r/w safety, as it could change due to inlining */ if (expr->rwparam >= 0) exec_check_rw_parameter(expr, expr->rwparam); } /* * Pass back previously-determined result type. */ *rettype = expr->expr_simple_type; *rettypmod = expr->expr_simple_typmod; /* * 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 (expr->expr_simple_lxid != curlxid) { oldcontext = MemoryContextSwitchTo(estate->simple_eval_estate->es_query_cxt); expr->expr_simple_state = ExecInitExpr(expr->expr_simple_expr, NULL); 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 advance the snapshot if we are in a non-read-only function. * Without this, stable functions within the expression would fail to see * updates made so far by our own function. */ oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); if (!estate->readonly_func) { CommandCounterIncrement(); PushActiveSnapshot(GetTransactionSnapshot()); } /* * Set up ParamListInfo to pass to executor. We need an unshared list if * it's going to include any R/W expanded-object pointer. For safety, * save and restore estate->paramLI->parserSetupArg around our use of the * param list. */ save_setup_arg = estate->paramLI->parserSetupArg; if (expr->rwparam >= 0) paramLI = setup_unshared_param_list(estate, expr); else paramLI = setup_param_list(estate, expr); econtext->ecxt_param_list_info = paramLI; /* * 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; estate->paramLI->parserSetupArg = save_setup_arg; if (!estate->readonly_func) PopActiveSnapshot(); MemoryContextSwitchTo(oldcontext); /* * Now we can release our refcount on the cached plan. */ ReleaseCachedPlan(cplan, true); /* * That's it. */ return true; } /* * Create a ParamListInfo to pass to SPI * * We share a single ParamListInfo array across all SPI calls made from this * estate, except calls creating cursors, which use setup_unshared_param_list * (see its comments for reasons why), and calls that pass a R/W expanded * object pointer. A shared array is generally OK since any given slot in * the array would need to contain the same current datum value no matter * which query or expression we're evaluating; but of course that doesn't * hold when a specific variable is being passed as a R/W pointer, because * other expressions in the same function probably don't want to do that. * * Note that paramLI->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. * * The general plan for passing parameters to SPI is that plain VAR datums * always have valid images in the shared param list. This is ensured by * assign_simple_var(), which also marks those params as PARAM_FLAG_CONST, * allowing the planner to use those values in custom plans. However, non-VAR * datums cannot conveniently be managed that way. For one thing, they could * throw errors (for example "no such record field") and we do not want that * to happen in a part of the expression that might never be evaluated at * runtime. For another thing, exec_eval_datum() may return short-lived * values stored in the estate's eval_mcontext, which will not necessarily * survive to the next SPI operation. And for a third thing, ROW * and RECFIELD datums' values depend on other datums, and we don't have a * cheap way to track that. Therefore, param slots for non-VAR datum types * are always reset here and then filled on-demand by plpgsql_param_fetch(). * We can save a few cycles by not bothering with the reset loop unless at * least one such param has actually been filled by plpgsql_param_fetch(). */ 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); /* * Expressions with R/W parameters can't use the shared param list. */ Assert(expr->rwparam == -1); /* * We only need a ParamListInfo if the expression has parameters. In * principle we should test with bms_is_empty(), but we use a not-null * test because it's faster. In current usage bits are never removed from * expr->paramnos, only added, so this test is correct anyway. */ if (expr->paramnos) { /* Use the common ParamListInfo */ paramLI = estate->paramLI; /* * If any resettable parameters have been passed to the executor since * last time, we need to reset those param slots to "invalid", for the * reasons mentioned in the comment above. */ if (estate->params_dirty) { Bitmapset *resettable_datums = estate->func->resettable_datums; int dno = -1; while ((dno = bms_next_member(resettable_datums, dno)) >= 0) { ParamExternData *prm = ¶mLI->params[dno]; prm->ptype = InvalidOid; } estate->params_dirty = false; } /* * 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; /* * Allow parameters that aren't needed by this expression to be * ignored. */ paramLI->paramMask = expr->paramnos; /* * 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; } /* * Create an unshared, short-lived ParamListInfo to pass to SPI * * When creating a cursor, we do not use the shared ParamListInfo array * but create a short-lived one that will contain only params actually * referenced by the query. The reason for this is that copyParamList() will * be used to copy the parameters into cursor-lifespan storage, and we don't * want it to copy anything that's not used by the specific cursor; that * could result in uselessly copying some large values. * * We also use this for expressions that are passing a R/W object pointer * to some trusted function. We don't want the R/W pointer to get into the * shared param list, where it could get passed to some less-trusted function. * * The result, if not NULL, is in the estate's eval_mcontext. * * XXX. Could we use ParamListInfo's new paramMask to avoid creating unshared * parameter lists? */ static ParamListInfo setup_unshared_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. In * principle we should test with bms_is_empty(), but we use a not-null * test because it's faster. In current usage bits are never removed from * expr->paramnos, only added, so this test is correct anyway. */ if (expr->paramnos) { int dno; /* initialize ParamListInfo with one entry per datum, all invalid */ paramLI = (ParamListInfo) eval_mcontext_alloc0(estate, offsetof(ParamListInfoData, params) + estate->ndatums * sizeof(ParamExternData)); paramLI->paramFetch = plpgsql_param_fetch; paramLI->paramFetchArg = (void *) estate; paramLI->parserSetup = (ParserSetupHook) plpgsql_parser_setup; paramLI->parserSetupArg = (void *) expr; paramLI->numParams = estate->ndatums; paramLI->paramMask = NULL; /* * Instantiate values for "safe" parameters of the expression. We * could skip this and leave them to be filled by plpgsql_param_fetch; * but then the values would not be available for query planning, * since the planner doesn't call the paramFetch hook. */ dno = -1; while ((dno = bms_next_member(expr->paramnos, dno)) >= 0) { PLpgSQL_datum *datum = estate->datums[dno]; if (datum->dtype == PLPGSQL_DTYPE_VAR) { PLpgSQL_var *var = (PLpgSQL_var *) datum; ParamExternData *prm = ¶mLI->params[dno]; if (dno == expr->rwparam) prm->value = var->value; else prm->value = MakeExpandedObjectReadOnly(var->value, var->isnull, var->datatype->typlen); prm->isnull = var->isnull; prm->pflags = PARAM_FLAG_CONST; prm->ptype = var->datatype->typoid; } } /* * 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 */ static void plpgsql_param_fetch(ParamListInfo params, int paramid) { int dno; PLpgSQL_execstate *estate; PLpgSQL_expr *expr; PLpgSQL_datum *datum; ParamExternData *prm; 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 do nothing 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)) return; if (params == estate->paramLI) { /* * We need to mark the shared params array dirty if we're about to * evaluate a resettable datum. */ switch (datum->dtype) { case PLPGSQL_DTYPE_ROW: case PLPGSQL_DTYPE_REC: case PLPGSQL_DTYPE_RECFIELD: estate->params_dirty = true; break; default: break; } } /* OK, evaluate the value and store into the appropriate paramlist slot */ prm = ¶ms->params[dno]; 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, * unless it's safe to pass as read-write. */ if (datum->dtype == PLPGSQL_DTYPE_VAR && dno != expr->rwparam) prm->value = MakeExpandedObjectReadOnly(prm->value, prm->isnull, ((PLpgSQL_var *) datum)->datatype->typlen); } /* ---------- * exec_move_row Move one tuple's values into a record or row * * Since this uses exec_assign_value, 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) { /* * Record is simple - just copy the tuple and its descriptor into the * record variable */ if (target->dtype == PLPGSQL_DTYPE_REC) { PLpgSQL_rec *rec = (PLpgSQL_rec *) target; /* * Copy input first, just in case it is pointing at variable's value */ if (HeapTupleIsValid(tup)) tup = heap_copytuple(tup); else if (tupdesc) { /* If we have a tupdesc but no data, form an all-nulls tuple */ bool *nulls; nulls = (bool *) eval_mcontext_alloc(estate, tupdesc->natts * sizeof(bool)); memset(nulls, true, tupdesc->natts * sizeof(bool)); tup = heap_form_tuple(tupdesc, NULL, nulls); } if (tupdesc) tupdesc = CreateTupleDescCopy(tupdesc); /* Free the old value ... */ if (rec->freetup) { heap_freetuple(rec->tup); rec->freetup = false; } if (rec->freetupdesc) { FreeTupleDesc(rec->tupdesc); rec->freetupdesc = false; } /* ... and install the new */ if (HeapTupleIsValid(tup)) { rec->tup = tup; rec->freetup = true; } else rec->tup = NULL; if (tupdesc) { rec->tupdesc = tupdesc; rec->freetupdesc = true; } else rec->tupdesc = NULL; return; } /* * Row is a bit more complicated in that we assign the individual * attributes of the tuple to the variables the row points to. * * NOTE: this code used to demand row->nfields == * HeapTupleHeaderGetNatts(tup->t_data), but that's wrong. The tuple * might have more fields than we expected if it's from an * inheritance-child table of the current table, or it might have fewer if * the table has had columns added by ALTER TABLE. Ignore extra columns * and assume NULL for missing columns, the same as heap_getattr would do. * We also have to skip over dropped columns in either the source or * destination. * * If we have no tuple 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; int td_natts = tupdesc ? tupdesc->natts : 0; int t_natts; int fnum; int anum; if (HeapTupleIsValid(tup)) t_natts = HeapTupleHeaderGetNatts(tup->t_data); else t_natts = 0; anum = 0; for (fnum = 0; fnum < row->nfields; fnum++) { PLpgSQL_var *var; Datum value; bool isnull; Oid valtype; int32 valtypmod; if (row->varnos[fnum] < 0) continue; /* skip dropped column in row struct */ 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) { if (anum < t_natts) value = SPI_getbinval(tup, tupdesc, anum + 1, &isnull); else { value = (Datum) 0; isnull = true; } valtype = TupleDescAttr(tupdesc, anum)->atttypid; valtypmod = TupleDescAttr(tupdesc, anum)->atttypmod; anum++; } else { value = (Datum) 0; isnull = true; valtype = UNKNOWNOID; valtypmod = -1; } exec_assign_value(estate, (PLpgSQL_datum *) var, value, isnull, valtype, valtypmod); } return; } elog(ERROR, "unsupported target"); } /* ---------- * 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; } if (row->varnos[i] < 0) /* should not happen */ elog(ERROR, "dropped rowtype entry for non-dropped column"); 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; } /* ---------- * get_tuple_from_datum extract a tuple from a composite Datum * * Returns a HeapTuple, freshly palloc'd in caller's context. * * Note: it's caller's responsibility to be sure value is of composite type. * ---------- */ static HeapTuple get_tuple_from_datum(Datum value) { HeapTupleHeader td = DatumGetHeapTupleHeader(value); HeapTupleData tmptup; /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; /* Build a copy and return it */ return heap_copytuple(&tmptup); } /* ---------- * get_tupdesc_from_datum get a tuple descriptor for a composite Datum * * Returns a pointer to the TupleDesc of the tuple'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. * ---------- */ static TupleDesc get_tupdesc_from_datum(Datum value) { HeapTupleHeader td = DatumGetHeapTupleHeader(value); Oid tupType; int32 tupTypmod; /* 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 get_tuple_from_datum() followed by exec_move_row(), * but we avoid constructing an intermediate physical copy of the tuple. * ---------- */ static void exec_move_row_from_datum(PLpgSQL_execstate *estate, PLpgSQL_variable *target, Datum value) { HeapTupleHeader td = DatumGetHeapTupleHeader(value); Oid tupType; int32 tupTypmod; TupleDesc tupdesc; HeapTupleData tmptup; /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; /* Do the move */ exec_move_row(estate, target, &tmptup, tupdesc); /* Release tupdesc usage count */ ReleaseTupleDesc(tupdesc); } /* ---------- * 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 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)) { 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; 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, (void *) &cast_key, HASH_FIND, NULL); if (cast_entry == NULL) { /* We've not looked up this coercion before */ Node *cast_expr; CaseTestExpr *placeholder; /* * Since we could easily fail (no such coercion), construct a * temporary coercion expression tree in the short-lived * eval_mcontext, then if successful copy it to cast_hash_context. */ 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 ASSIGNMENT coercion because that's the * closest match to plpgsql's historical behavior; in particular, * EXPLICIT coercion would allow silent truncation to a destination * varchar/bpchar's length, which we do not want. * * 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_ASSIGNMENT, 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. */ 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 */ /* Detect whether we have a no-op (RelabelType) coercion */ if (IsA(cast_expr, RelabelType) && ((RelabelType *) cast_expr)->arg == (Expr *) placeholder) cast_expr = NULL; if (cast_expr) { /* ExecInitExpr assumes we've planned the expression */ cast_expr = (Node *) expression_planner((Expr *) cast_expr); /* Now copy the tree into cast_hash_context */ MemoryContextSwitchTo(estate->cast_hash_context); cast_expr = copyObject(cast_expr); } MemoryContextSwitchTo(oldcontext); /* Now we can fill in a hashtable entry. */ cast_entry = (plpgsql_CastHashEntry *) hash_search(estate->cast_hash, (void *) &cast_key, HASH_ENTER, &found); Assert(!found); /* wasn't there a moment ago */ cast_entry->cast_expr = (Expr *) cast_expr; cast_entry->cast_exprstate = NULL; cast_entry->cast_in_use = false; cast_entry->cast_lxid = InvalidLocalTransactionId; } /* Done if we have determined that this is a no-op cast. */ if (cast_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(cast_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. * ---------- */ 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; /* * 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. */ 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); /* Share the remaining work with replan code path */ exec_save_simple_expr(expr, cplan); /* Release our plan refcount */ ReleaseCachedPlan(cplan, true); } /* * 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 * force_parallel_mode 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 = castNode(TargetEntry, linitial(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_generation = cplan->generation; 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); } /* * 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->rwparam to the * dno of the target variable (x) if safe, or -1 if not safe. */ static void exec_check_rw_parameter(PLpgSQL_expr *expr, int target_dno) { Oid funcid; List *fargs; ListCell *lc; /* Assume unsafe */ expr->rwparam = -1; /* * If the expression isn't simple, there's no point in trying to optimize * (because the exec_run_select code path will flatten any expanded result * anyway). Even without that, this seems like a good safety restriction. */ if (expr->expr_simple_expr == NULL) return; /* * If target variable isn't referenced by expression, no need to look * further. */ if (!bms_is_member(target_dno, expr->paramnos)) return; /* * Top level of expression must be a simple FuncExpr or OpExpr. */ 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 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 only appear as a * direct argument of the top-level function. */ foreach(lc, fargs) { Node *arg = (Node *) lfirst(lc); /* A Param is OK, whether it's the target variable or not */ if (arg && IsA(arg, Param)) continue; /* Otherwise, argument expression must not reference target */ if (contains_target_param(arg, &target_dno)) return; } /* OK, we can pass target as a read-write parameter */ expr->rwparam = target_dno; } /* * Recursively check for a Param referencing the target variable */ static bool contains_target_param(Node *node, int *target_dno) { if (node == NULL) return false; if (IsA(node, Param)) { Param *param = (Param *) node; if (param->paramkind == PARAM_EXTERN && param->paramid == *target_dno + 1) return true; return false; } return expression_tree_walker(node, contains_target_param, (void *) target_dno); } /* ---------- * 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. */ 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 executing a DO block; the * required EState was already made by plpgsql_inline_handler. */ if (estate->simple_eval_estate == NULL) { MemoryContext oldcontext; Assert(shared_simple_eval_estate == NULL); oldcontext = MemoryContextSwitchTo(TopTransactionContext); shared_simple_eval_estate = CreateExecutorState(); estate->simple_eval_estate = shared_simple_eval_estate; MemoryContextSwitchTo(oldcontext); } /* * 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. */ void plpgsql_xact_cb(XactEvent event, void *arg) { /* * If we are doing a clean transaction shutdown, free the EState (so that * any remaining resources will be released correctly). In an abort, we * expect the regular abort recovery procedures to release everything of * interest. */ if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE) { /* Shouldn't be any econtext stack entries left at commit */ Assert(simple_econtext_stack == NULL); if (shared_simple_eval_estate) FreeExecutorState(shared_simple_eval_estate); shared_simple_eval_estate = NULL; } else if (event == XACT_EVENT_ABORT) { simple_econtext_stack = NULL; shared_simple_eval_estate = 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 forget to update the paramLI image. */ static void assign_simple_var(PLpgSQL_execstate *estate, PLpgSQL_var *var, Datum newvalue, bool isnull, bool freeable) { ParamExternData *prm; Assert(var->dtype == PLPGSQL_DTYPE_VAR); /* 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; /* And update the image in the common parameter list */ prm = &estate->paramLI->params[var->dno]; prm->value = MakeExpandedObjectReadOnly(newvalue, isnull, var->datatype->typlen); prm->isnull = isnull; /* these might be set already, but let's be sure */ prm->pflags = PARAM_FLAG_CONST; prm->ptype = var->datatype->typoid; } /* * 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); } /* * 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 PreparedParamsData * exec_eval_using_params(PLpgSQL_execstate *estate, List *params) { PreparedParamsData *ppd; MemoryContext stmt_mcontext = get_stmt_mcontext(estate); int nargs; int i; ListCell *lc; ppd = (PreparedParamsData *) MemoryContextAlloc(stmt_mcontext, sizeof(PreparedParamsData)); nargs = list_length(params); ppd->nargs = nargs; ppd->types = (Oid *) MemoryContextAlloc(stmt_mcontext, nargs * sizeof(Oid)); ppd->values = (Datum *) MemoryContextAlloc(stmt_mcontext, nargs * sizeof(Datum)); ppd->nulls = (char *) MemoryContextAlloc(stmt_mcontext, nargs * sizeof(char)); i = 0; foreach(lc, params) { PLpgSQL_expr *param = (PLpgSQL_expr *) lfirst(lc); bool isnull; int32 ppdtypmod; MemoryContext oldcontext; ppd->values[i] = exec_eval_expr(estate, param, &isnull, &ppd->types[i], &ppdtypmod); ppd->nulls[i] = isnull ? 'n' : ' '; oldcontext = MemoryContextSwitchTo(stmt_mcontext); if (ppd->types[i] == UNKNOWNOID) { /* * Treat 'unknown' parameters as text, since that's what most * people would expect. SPI_execute_with_args 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. */ ppd->types[i] = TEXTOID; if (!isnull) ppd->values[i] = CStringGetTextDatum(DatumGetCString(ppd->values[i])); } /* pass-by-ref non null values must be copied into stmt_mcontext */ else if (!isnull) { int16 typLen; bool typByVal; get_typlenbyval(ppd->types[i], &typLen, &typByVal); if (!typByVal) ppd->values[i] = datumCopy(ppd->values[i], typByVal, typLen); } MemoryContextSwitchTo(oldcontext); exec_eval_cleanup(estate); i++; } return ppd; } /* * 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; 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_open_with_args even when there are no params, because this * avoids making and freeing one copy of the plan. */ if (params) { PreparedParamsData *ppd; ppd = exec_eval_using_params(estate, params); portal = SPI_cursor_open_with_args(portalname, querystr, ppd->nargs, ppd->types, ppd->values, ppd->nulls, estate->readonly_func, cursorOptions); } else { portal = SPI_cursor_open_with_args(portalname, querystr, 0, NULL, NULL, NULL, estate->readonly_func, cursorOptions); } 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 { char *value = convert_value_to_string(estate, paramdatum, paramtypeid); char *p; appendStringInfoCharMacro(¶mstr, '\''); for (p = value; *p; p++) { if (*p == '\'') /* double single quotes */ appendStringInfoCharMacro(¶mstr, *p); appendStringInfoCharMacro(¶mstr, *p); } appendStringInfoCharMacro(¶mstr, '\''); } paramno++; } MemoryContextSwitchTo(oldcontext); return paramstr.data; } /* * Return a formatted string with information about PreparedParamsData, or NULL * if there are no parameters. * The result is in the eval_mcontext. */ static char * format_preparedparamsdata(PLpgSQL_execstate *estate, const PreparedParamsData *ppd) { int paramno; StringInfoData paramstr; MemoryContext oldcontext; if (!ppd) return NULL; oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate)); initStringInfo(¶mstr); for (paramno = 0; paramno < ppd->nargs; paramno++) { appendStringInfo(¶mstr, "%s$%d = ", paramno > 0 ? ", " : "", paramno + 1); if (ppd->nulls[paramno] == 'n') appendStringInfoString(¶mstr, "NULL"); else { char *value = convert_value_to_string(estate, ppd->values[paramno], ppd->types[paramno]); char *p; appendStringInfoCharMacro(¶mstr, '\''); for (p = value; *p; p++) { if (*p == '\'') /* double single quotes */ appendStringInfoCharMacro(¶mstr, *p); appendStringInfoCharMacro(¶mstr, *p); } appendStringInfoCharMacro(¶mstr, '\''); } } MemoryContextSwitchTo(oldcontext); return paramstr.data; }