/*------------------------------------------------------------------------- * * parse_func.c * handle function calls in parser * * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.134 2002/08/08 01:44:30 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/heapam.h" #include "catalog/catname.h" #include "catalog/namespace.h" #include "catalog/pg_inherits.h" #include "catalog/pg_proc.h" #include "lib/stringinfo.h" #include "nodes/makefuncs.h" #include "parser/parse_coerce.h" #include "parser/parse_expr.h" #include "parser/parse_func.h" #include "parser/parse_relation.h" #include "parser/parse_type.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/lsyscache.h" #include "utils/syscache.h" static Node *ParseComplexProjection(ParseState *pstate, char *funcname, Node *first_arg); static Oid **argtype_inherit(int nargs, Oid *argtypes); static int find_inheritors(Oid relid, Oid **supervec); static Oid **gen_cross_product(InhPaths *arginh, int nargs); static void make_arguments(ParseState *pstate, int nargs, List *fargs, Oid *input_typeids, Oid *function_typeids); static int match_argtypes(int nargs, Oid *input_typeids, FuncCandidateList function_typeids, FuncCandidateList *candidates); static FieldSelect *setup_field_select(Node *input, char *attname, Oid relid); static FuncCandidateList func_select_candidate(int nargs, Oid *input_typeids, FuncCandidateList candidates); static void unknown_attribute(const char *schemaname, const char *relname, const char *attname); /* * Parse a function call * * For historical reasons, Postgres tries to treat the notations tab.col * and col(tab) as equivalent: if a single-argument function call has an * argument of complex type and the (unqualified) function name matches * any attribute of the type, we take it as a column projection. * * Hence, both cases come through here. The is_column parameter tells us * which syntactic construct is actually being dealt with, but this is * intended to be used only to deliver an appropriate error message, * not to affect the semantics. When is_column is true, we should have * a single argument (the putative table), unqualified function name * equal to the column name, and no aggregate decoration. * * In the function-call case, the argument expressions have been transformed * already. In the column case, we may get either a transformed expression * or a RangeVar node as argument. */ Node * ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs, bool agg_star, bool agg_distinct, bool is_column) { Oid rettype; Oid funcid; List *i; Node *first_arg = NULL; int nargs = length(fargs); int argn; Oid oid_array[FUNC_MAX_ARGS]; Oid *true_oid_array; Node *retval; bool retset; FuncDetailCode fdresult; /* * Most of the rest of the parser just assumes that functions do not * have more than FUNC_MAX_ARGS parameters. We have to test here to * protect against array overruns, etc. Of course, this may not be a * function, but the test doesn't hurt. */ if (nargs > FUNC_MAX_ARGS) elog(ERROR, "Cannot pass more than %d arguments to a function", FUNC_MAX_ARGS); if (fargs) { first_arg = lfirst(fargs); if (first_arg == NULL) /* should not happen */ elog(ERROR, "Function '%s' does not allow NULL input", NameListToString(funcname)); } /* * check for column projection: if function has one argument, and that * argument is of complex type, and function name is not qualified, * then the "function call" could be a projection. We also check * that there wasn't any aggregate decoration. */ if (nargs == 1 && !agg_star && !agg_distinct && length(funcname) == 1) { char *cname = strVal(lfirst(funcname)); /* Is it a not-yet-transformed RangeVar node? */ if (IsA(first_arg, RangeVar)) { /* First arg is a relation. This could be a projection. */ retval = qualifiedNameToVar(pstate, ((RangeVar *) first_arg)->schemaname, ((RangeVar *) first_arg)->relname, cname, true); if (retval) return retval; } else if (ISCOMPLEX(exprType(first_arg))) { /* * Attempt to handle projection of a complex argument. If * ParseComplexProjection can't handle the projection, we have * to keep going. */ retval = ParseComplexProjection(pstate, cname, first_arg); if (retval) return retval; } } /* * Okay, it's not a column projection, so it must really be a function. * Extract arg type info and transform RangeVar arguments into varnodes * of the appropriate form. */ MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid)); argn = 0; foreach(i, fargs) { Node *arg = lfirst(i); Oid toid; if (IsA(arg, RangeVar)) { char *schemaname; char *relname; RangeTblEntry *rte; int vnum; int sublevels_up; /* * a relation: look it up in the range table, or add if needed */ schemaname = ((RangeVar *) arg)->schemaname; relname = ((RangeVar *) arg)->relname; rte = refnameRangeTblEntry(pstate, schemaname, relname, &sublevels_up); if (rte == NULL) rte = addImplicitRTE(pstate, (RangeVar *) arg); vnum = RTERangeTablePosn(pstate, rte, &sublevels_up); /* * The parameter to be passed to the function is the whole * tuple from the relation. We build a special VarNode to * reflect this -- it has varno set to the correct range table * entry, but has varattno == 0 to signal that the whole tuple * is the argument. Also, it has typmod set to * sizeof(Pointer) to signal that the runtime representation * will be a pointer not an Oid. */ switch (rte->rtekind) { case RTE_RELATION: toid = get_rel_type_id(rte->relid); if (!OidIsValid(toid)) elog(ERROR, "Cannot find type OID for relation %u", rte->relid); break; case RTE_FUNCTION: toid = exprType(rte->funcexpr); break; default: /* * RTE is a join or subselect; must fail for lack of a * named tuple type */ if (is_column) unknown_attribute(schemaname, relname, strVal(lfirst(funcname))); else elog(ERROR, "Cannot pass result of sub-select or join %s to a function", relname); toid = InvalidOid; /* keep compiler quiet */ break; } /* replace RangeVar in the arg list */ lfirst(i) = makeVar(vnum, InvalidAttrNumber, toid, sizeof(Pointer), sublevels_up); } else toid = exprType(arg); oid_array[argn++] = toid; } /* * func_get_detail looks up the function in the catalogs, does * disambiguation for polymorphic functions, handles inheritance, * and returns the funcid and type and set or singleton status of * the function's return value. it also returns the true argument * types to the function. */ fdresult = func_get_detail(funcname, fargs, nargs, oid_array, &funcid, &rettype, &retset, &true_oid_array); if (fdresult == FUNCDETAIL_COERCION) { /* * We can do it as a trivial coercion. coerce_type can handle * these cases, so why duplicate code... */ return coerce_type(pstate, lfirst(fargs), oid_array[0], rettype, -1, true); } else if (fdresult == FUNCDETAIL_NORMAL) { /* * Normal function found; was there anything indicating it must be * an aggregate? */ if (agg_star) elog(ERROR, "%s(*) specified, but %s is not an aggregate function", NameListToString(funcname), NameListToString(funcname)); if (agg_distinct) elog(ERROR, "DISTINCT specified, but %s is not an aggregate function", NameListToString(funcname)); } else if (fdresult != FUNCDETAIL_AGGREGATE) { /* * Oops. Time to die. * * If we are dealing with the attribute notation rel.function, * give an error message that is appropriate for that case. */ if (is_column) { char *colname = strVal(lfirst(funcname)); Oid relTypeId; Assert(nargs == 1); if (IsA(first_arg, RangeVar)) unknown_attribute(((RangeVar *) first_arg)->schemaname, ((RangeVar *) first_arg)->relname, colname); relTypeId = exprType(first_arg); if (!ISCOMPLEX(relTypeId)) elog(ERROR, "Attribute notation .%s applied to type %s, which is not a complex type", colname, format_type_be(relTypeId)); else elog(ERROR, "Attribute \"%s\" not found in datatype %s", colname, format_type_be(relTypeId)); } /* * Else generate a detailed complaint for a function */ func_error(NULL, funcname, nargs, oid_array, "Unable to identify a function that satisfies the " "given argument types" "\n\tYou may need to add explicit typecasts"); } /* perform the necessary typecasting of arguments */ make_arguments(pstate, nargs, fargs, oid_array, true_oid_array); /* build the appropriate output structure */ if (fdresult == FUNCDETAIL_NORMAL) { Expr *expr = makeNode(Expr); Func *funcnode = makeNode(Func); funcnode->funcid = funcid; funcnode->funcresulttype = rettype; funcnode->funcretset = retset; funcnode->func_fcache = NULL; expr->typeOid = rettype; expr->opType = FUNC_EXPR; expr->oper = (Node *) funcnode; expr->args = fargs; retval = (Node *) expr; } else { /* aggregate function */ Aggref *aggref = makeNode(Aggref); aggref->aggfnoid = funcid; aggref->aggtype = rettype; aggref->target = lfirst(fargs); aggref->aggstar = agg_star; aggref->aggdistinct = agg_distinct; retval = (Node *) aggref; if (retset) elog(ERROR, "Aggregates may not return sets"); pstate->p_hasAggs = true; } return retval; } /* match_argtypes() * * Given a list of possible typeid arrays to a function and an array of * input typeids, produce a shortlist of those function typeid arrays * that match the input typeids (either exactly or by coercion), and * return the number of such arrays. * * NB: okay to modify input list structure, as long as we find at least * one match. */ static int match_argtypes(int nargs, Oid *input_typeids, FuncCandidateList function_typeids, FuncCandidateList *candidates) /* return value */ { FuncCandidateList current_candidate; FuncCandidateList next_candidate; int ncandidates = 0; *candidates = NULL; for (current_candidate = function_typeids; current_candidate != NULL; current_candidate = next_candidate) { next_candidate = current_candidate->next; if (can_coerce_type(nargs, input_typeids, current_candidate->args, false)) { current_candidate->next = *candidates; *candidates = current_candidate; ncandidates++; } } return ncandidates; } /* match_argtypes() */ /* func_select_candidate() * Given the input argtype array and more than one candidate * for the function, attempt to resolve the conflict. * Returns the selected candidate if the conflict can be resolved, * otherwise returns NULL. * * By design, this is pretty similar to oper_select_candidate in parse_oper.c. * However, the calling convention is a little different: we assume the caller * already pruned away "candidates" that aren't actually coercion-compatible * with the input types, whereas oper_select_candidate must do that itself. */ static FuncCandidateList func_select_candidate(int nargs, Oid *input_typeids, FuncCandidateList candidates) { FuncCandidateList current_candidate; FuncCandidateList last_candidate; Oid *current_typeids; Oid current_type; int i; int ncandidates; int nbestMatch, nmatch; CATEGORY slot_category[FUNC_MAX_ARGS], current_category; bool slot_has_preferred_type[FUNC_MAX_ARGS]; bool resolved_unknowns; /* * Run through all candidates and keep those with the most matches on * exact types. Keep all candidates if none match. */ ncandidates = 0; nbestMatch = 0; last_candidate = NULL; for (current_candidate = candidates; current_candidate != NULL; current_candidate = current_candidate->next) { current_typeids = current_candidate->args; nmatch = 0; for (i = 0; i < nargs; i++) { if (input_typeids[i] != UNKNOWNOID && current_typeids[i] == input_typeids[i]) nmatch++; } /* take this one as the best choice so far? */ if ((nmatch > nbestMatch) || (last_candidate == NULL)) { nbestMatch = nmatch; candidates = current_candidate; last_candidate = current_candidate; ncandidates = 1; } /* no worse than the last choice, so keep this one too? */ else if (nmatch == nbestMatch) { last_candidate->next = current_candidate; last_candidate = current_candidate; ncandidates++; } /* otherwise, don't bother keeping this one... */ } if (last_candidate) /* terminate rebuilt list */ last_candidate->next = NULL; if (ncandidates == 1) return candidates; /* * Still too many candidates? Run through all candidates and keep * those with the most matches on exact types + binary-compatible * types. Keep all candidates if none match. */ ncandidates = 0; nbestMatch = 0; last_candidate = NULL; for (current_candidate = candidates; current_candidate != NULL; current_candidate = current_candidate->next) { current_typeids = current_candidate->args; nmatch = 0; for (i = 0; i < nargs; i++) { if (input_typeids[i] != UNKNOWNOID) { if (IsBinaryCompatible(current_typeids[i], input_typeids[i])) nmatch++; } } /* take this one as the best choice so far? */ if ((nmatch > nbestMatch) || (last_candidate == NULL)) { nbestMatch = nmatch; candidates = current_candidate; last_candidate = current_candidate; ncandidates = 1; } /* no worse than the last choice, so keep this one too? */ else if (nmatch == nbestMatch) { last_candidate->next = current_candidate; last_candidate = current_candidate; ncandidates++; } /* otherwise, don't bother keeping this one... */ } if (last_candidate) /* terminate rebuilt list */ last_candidate->next = NULL; if (ncandidates == 1) return candidates; /* * Still too many candidates? Now look for candidates which are * preferred types at the args that will require coercion. Keep all * candidates if none match. */ ncandidates = 0; nbestMatch = 0; last_candidate = NULL; for (current_candidate = candidates; current_candidate != NULL; current_candidate = current_candidate->next) { current_typeids = current_candidate->args; nmatch = 0; for (i = 0; i < nargs; i++) { if (input_typeids[i] != UNKNOWNOID) { current_category = TypeCategory(current_typeids[i]); if (current_typeids[i] == input_typeids[i] || IsPreferredType(current_category, current_typeids[i])) nmatch++; } } if ((nmatch > nbestMatch) || (last_candidate == NULL)) { nbestMatch = nmatch; candidates = current_candidate; last_candidate = current_candidate; ncandidates = 1; } else if (nmatch == nbestMatch) { last_candidate->next = current_candidate; last_candidate = current_candidate; ncandidates++; } } if (last_candidate) /* terminate rebuilt list */ last_candidate->next = NULL; if (ncandidates == 1) return candidates; /* * Still too many candidates? Try assigning types for the unknown * columns. * * We do this by examining each unknown argument position to see if we * can determine a "type category" for it. If any candidate has an * input datatype of STRING category, use STRING category (this bias * towards STRING is appropriate since unknown-type literals look like * strings). Otherwise, if all the candidates agree on the type * category of this argument position, use that category. Otherwise, * fail because we cannot determine a category. * * If we are able to determine a type category, also notice whether any * of the candidates takes a preferred datatype within the category. * * Having completed this examination, remove candidates that accept the * wrong category at any unknown position. Also, if at least one * candidate accepted a preferred type at a position, remove * candidates that accept non-preferred types. * * If we are down to one candidate at the end, we win. */ resolved_unknowns = false; for (i = 0; i < nargs; i++) { bool have_conflict; if (input_typeids[i] != UNKNOWNOID) continue; resolved_unknowns = true; /* assume we can do it */ slot_category[i] = INVALID_TYPE; slot_has_preferred_type[i] = false; have_conflict = false; for (current_candidate = candidates; current_candidate != NULL; current_candidate = current_candidate->next) { current_typeids = current_candidate->args; current_type = current_typeids[i]; current_category = TypeCategory(current_type); if (slot_category[i] == INVALID_TYPE) { /* first candidate */ slot_category[i] = current_category; slot_has_preferred_type[i] = IsPreferredType(current_category, current_type); } else if (current_category == slot_category[i]) { /* more candidates in same category */ slot_has_preferred_type[i] |= IsPreferredType(current_category, current_type); } else { /* category conflict! */ if (current_category == STRING_TYPE) { /* STRING always wins if available */ slot_category[i] = current_category; slot_has_preferred_type[i] = IsPreferredType(current_category, current_type); } else { /* * Remember conflict, but keep going (might find * STRING) */ have_conflict = true; } } } if (have_conflict && slot_category[i] != STRING_TYPE) { /* Failed to resolve category conflict at this position */ resolved_unknowns = false; break; } } if (resolved_unknowns) { /* Strip non-matching candidates */ ncandidates = 0; last_candidate = NULL; for (current_candidate = candidates; current_candidate != NULL; current_candidate = current_candidate->next) { bool keepit = true; current_typeids = current_candidate->args; for (i = 0; i < nargs; i++) { if (input_typeids[i] != UNKNOWNOID) continue; current_type = current_typeids[i]; current_category = TypeCategory(current_type); if (current_category != slot_category[i]) { keepit = false; break; } if (slot_has_preferred_type[i] && !IsPreferredType(current_category, current_type)) { keepit = false; break; } } if (keepit) { /* keep this candidate */ last_candidate = current_candidate; ncandidates++; } else { /* forget this candidate */ if (last_candidate) last_candidate->next = current_candidate->next; else candidates = current_candidate->next; } } if (last_candidate) /* terminate rebuilt list */ last_candidate->next = NULL; } if (ncandidates == 1) return candidates; return NULL; /* failed to determine a unique candidate */ } /* func_select_candidate() */ /* func_get_detail() * * Find the named function in the system catalogs. * * Attempt to find the named function in the system catalogs with * arguments exactly as specified, so that the normal case * (exact match) is as quick as possible. * * If an exact match isn't found: * 1) check for possible interpretation as a trivial type coercion * 2) get a vector of all possible input arg type arrays constructed * from the superclasses of the original input arg types * 3) get a list of all possible argument type arrays to the function * with given name and number of arguments * 4) for each input arg type array from vector #1: * a) find how many of the function arg type arrays from list #2 * it can be coerced to * b) if the answer is one, we have our function * c) if the answer is more than one, attempt to resolve the conflict * d) if the answer is zero, try the next array from vector #1 * * Note: we rely primarily on nargs/argtypes as the argument description. * The actual expression node list is passed in fargs so that we can check * for type coercion of a constant. Some callers pass fargs == NIL * indicating they don't want that check made. */ FuncDetailCode func_get_detail(List *funcname, List *fargs, int nargs, Oid *argtypes, Oid *funcid, /* return value */ Oid *rettype, /* return value */ bool *retset, /* return value */ Oid **true_typeids) /* return value */ { FuncCandidateList function_typeids; FuncCandidateList best_candidate; /* Get list of possible candidates from namespace search */ function_typeids = FuncnameGetCandidates(funcname, nargs); /* * See if there is an exact match */ for (best_candidate = function_typeids; best_candidate != NULL; best_candidate = best_candidate->next) { if (memcmp(argtypes, best_candidate->args, nargs * sizeof(Oid)) == 0) break; } if (best_candidate == NULL) { /* * If we didn't find an exact match, next consider the possibility * that this is really a type-coercion request: a single-argument * function call where the function name is a type name. If so, * and if we can do the coercion trivially (no run-time function * call needed), then go ahead and treat the "function call" as a * coercion. This interpretation needs to be given higher * priority than interpretations involving a type coercion * followed by a function call, otherwise we can produce * surprising results. For example, we want "text(varchar)" to be * interpreted as a trivial coercion, not as "text(name(varchar))" * which the code below this point is entirely capable of * selecting. * * "Trivial" coercions are ones that involve binary-compatible types * and ones that are coercing a previously-unknown-type literal * constant to a specific type. * * NB: it's important that this code stays in sync with what * coerce_type can do, because the caller will try to apply * coerce_type if we return FUNCDETAIL_COERCION. If we return * that result for something coerce_type can't handle, we'll cause * infinite recursion between this module and coerce_type! */ if (nargs == 1 && fargs != NIL) { Oid targetType; TypeName *tn = makeNode(TypeName); tn->names = funcname; tn->typmod = -1; targetType = LookupTypeName(tn); if (OidIsValid(targetType) && !ISCOMPLEX(targetType)) { Oid sourceType = argtypes[0]; Node *arg1 = lfirst(fargs); if ((sourceType == UNKNOWNOID && IsA(arg1, Const)) || IsBinaryCompatible(sourceType, targetType)) { /* Yup, it's a type coercion */ *funcid = InvalidOid; *rettype = targetType; *retset = false; *true_typeids = argtypes; return FUNCDETAIL_COERCION; } } } /* * didn't find an exact match, so now try to match up * candidates... */ if (function_typeids != NULL) { Oid **input_typeid_vector = NULL; Oid *current_input_typeids; /* * First we will search with the given argtypes, then with * variants based on replacing complex types with their * inheritance ancestors. Stop as soon as any match is found. */ current_input_typeids = argtypes; do { FuncCandidateList current_function_typeids; int ncandidates; ncandidates = match_argtypes(nargs, current_input_typeids, function_typeids, ¤t_function_typeids); /* one match only? then run with it... */ if (ncandidates == 1) { best_candidate = current_function_typeids; break; } /* * multiple candidates? then better decide or throw an * error... */ if (ncandidates > 1) { best_candidate = func_select_candidate(nargs, current_input_typeids, current_function_typeids); /* * If we were able to choose a best candidate, we're * done. Otherwise, ambiguous function call, so fail * by exiting loop with best_candidate still NULL. * Either way, we're outta here. */ break; } /* * No match here, so try the next inherited type vector. * First time through, we need to compute the list of * vectors. */ if (input_typeid_vector == NULL) input_typeid_vector = argtype_inherit(nargs, argtypes); current_input_typeids = *input_typeid_vector++; } while (current_input_typeids != NULL); } } if (best_candidate) { HeapTuple ftup; Form_pg_proc pform; FuncDetailCode result; *funcid = best_candidate->oid; *true_typeids = best_candidate->args; ftup = SearchSysCache(PROCOID, ObjectIdGetDatum(best_candidate->oid), 0, 0, 0); if (!HeapTupleIsValid(ftup)) /* should not happen */ elog(ERROR, "function %u not found", best_candidate->oid); pform = (Form_pg_proc) GETSTRUCT(ftup); *rettype = pform->prorettype; *retset = pform->proretset; result = pform->proisagg ? FUNCDETAIL_AGGREGATE : FUNCDETAIL_NORMAL; ReleaseSysCache(ftup); return result; } return FUNCDETAIL_NOTFOUND; } /* func_get_detail() */ /* * argtype_inherit() -- Construct an argtype vector reflecting the * inheritance properties of the supplied argv. * * This function is used to disambiguate among functions with the * same name but different signatures. It takes an array of input * type ids. For each type id in the array that's a complex type * (a class), it walks up the inheritance tree, finding all * superclasses of that type. A vector of new Oid type arrays * is returned to the caller, reflecting the structure of the * inheritance tree above the supplied arguments. * * The order of this vector is as follows: all superclasses of the * rightmost complex class are explored first. The exploration * continues from right to left. This policy means that we favor * keeping the leftmost argument type as low in the inheritance tree * as possible. This is intentional; it is exactly what we need to * do for method dispatch. The last type array we return is all * zeroes. This will match any functions for which return types are * not defined. There are lots of these (mostly builtins) in the * catalogs. */ static Oid ** argtype_inherit(int nargs, Oid *argtypes) { Oid relid; int i; InhPaths arginh[FUNC_MAX_ARGS]; for (i = 0; i < FUNC_MAX_ARGS; i++) { if (i < nargs) { arginh[i].self = argtypes[i]; if ((relid = typeidTypeRelid(argtypes[i])) != InvalidOid) arginh[i].nsupers = find_inheritors(relid, &(arginh[i].supervec)); else { arginh[i].nsupers = 0; arginh[i].supervec = (Oid *) NULL; } } else { arginh[i].self = InvalidOid; arginh[i].nsupers = 0; arginh[i].supervec = (Oid *) NULL; } } /* return an ordered cross-product of the classes involved */ return gen_cross_product(arginh, nargs); } static int find_inheritors(Oid relid, Oid **supervec) { Relation inhrel; HeapScanDesc inhscan; ScanKeyData skey; HeapTuple inhtup; Oid *relidvec; int nvisited; List *visited, *queue; List *elt; bool newrelid; nvisited = 0; queue = NIL; visited = NIL; inhrel = heap_openr(InheritsRelationName, AccessShareLock); /* * Use queue to do a breadth-first traversal of the inheritance graph * from the relid supplied up to the root. At the top of the loop, * relid is the OID of the reltype to check next, queue is the list of * pending rels to check after this one, and visited is the list of * relids we need to output. */ do { /* find all types this relid inherits from, and add them to queue */ ScanKeyEntryInitialize(&skey, 0x0, Anum_pg_inherits_inhrelid, F_OIDEQ, ObjectIdGetDatum(relid)); inhscan = heap_beginscan(inhrel, SnapshotNow, 1, &skey); while ((inhtup = heap_getnext(inhscan, ForwardScanDirection)) != NULL) { Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inhtup); queue = lappendi(queue, inh->inhparent); } heap_endscan(inhscan); /* pull next unvisited relid off the queue */ newrelid = false; while (queue != NIL) { relid = lfirsti(queue); queue = lnext(queue); if (!intMember(relid, visited)) { newrelid = true; break; } } if (newrelid) { visited = lappendi(visited, relid); nvisited++; } } while (newrelid); heap_close(inhrel, AccessShareLock); if (nvisited > 0) { relidvec = (Oid *) palloc(nvisited * sizeof(Oid)); *supervec = relidvec; foreach(elt, visited) { /* return the type id, rather than the relation id */ *relidvec++ = get_rel_type_id((Oid) lfirsti(elt)); } } else *supervec = (Oid *) NULL; freeList(visited); /* * there doesn't seem to be any equally easy way to release the queue * list cells, but since they're palloc'd space it's not critical. */ return nvisited; } static Oid ** gen_cross_product(InhPaths *arginh, int nargs) { int nanswers; Oid **result, **iter; Oid *oneres; int i, j; int cur[FUNC_MAX_ARGS]; nanswers = 1; for (i = 0; i < nargs; i++) { nanswers *= (arginh[i].nsupers + 2); cur[i] = 0; } iter = result = (Oid **) palloc(sizeof(Oid *) * nanswers); /* compute the cross product from right to left */ for (;;) { oneres = (Oid *) palloc(FUNC_MAX_ARGS * sizeof(Oid)); MemSet(oneres, 0, FUNC_MAX_ARGS * sizeof(Oid)); for (i = nargs - 1; i >= 0 && cur[i] > arginh[i].nsupers; i--) continue; /* if we're done, terminate with NULL pointer */ if (i < 0) { *iter = NULL; return result; } /* no, increment this column and zero the ones after it */ cur[i] = cur[i] + 1; for (j = nargs - 1; j > i; j--) cur[j] = 0; for (i = 0; i < nargs; i++) { if (cur[i] == 0) oneres[i] = arginh[i].self; else if (cur[i] > arginh[i].nsupers) oneres[i] = 0; /* wild card */ else oneres[i] = arginh[i].supervec[cur[i] - 1]; } *iter++ = oneres; } } /* * Given two type OIDs, determine whether the first is a complex type * (class type) that inherits from the second. */ bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId) { Oid relid; Oid *supervec; int nsupers, i; bool result; if (!ISCOMPLEX(subclassTypeId) || !ISCOMPLEX(superclassTypeId)) return false; relid = typeidTypeRelid(subclassTypeId); if (relid == InvalidOid) return false; nsupers = find_inheritors(relid, &supervec); result = false; for (i = 0; i < nsupers; i++) { if (supervec[i] == superclassTypeId) { result = true; break; } } if (supervec) pfree(supervec); return result; } /* make_arguments() * Given the number and types of arguments to a function, and the * actual arguments and argument types, do the necessary typecasting. */ static void make_arguments(ParseState *pstate, int nargs, List *fargs, Oid *input_typeids, Oid *function_typeids) { List *current_fargs; int i; for (i = 0, current_fargs = fargs; i < nargs; i++, current_fargs = lnext(current_fargs)) { /* types don't match? then force coercion using a function call... */ if (input_typeids[i] != function_typeids[i]) { lfirst(current_fargs) = coerce_type(pstate, lfirst(current_fargs), input_typeids[i], function_typeids[i], -1, false); } } } /* * setup_field_select * Build a FieldSelect node that says which attribute to project to. * This routine is called by ParseFuncOrColumn() when we have found * a projection on a function result or parameter. */ static FieldSelect * setup_field_select(Node *input, char *attname, Oid relid) { FieldSelect *fselect = makeNode(FieldSelect); AttrNumber attno; attno = get_attnum(relid, attname); if (attno == InvalidAttrNumber) elog(ERROR, "Relation \"%s\" has no column \"%s\"", get_rel_name(relid), attname); fselect->arg = input; fselect->fieldnum = attno; fselect->resulttype = get_atttype(relid, attno); fselect->resulttypmod = get_atttypmod(relid, attno); return fselect; } /* * ParseComplexProjection - * handles function calls with a single argument that is of complex type. * If the function call is actually a column projection, return a suitably * transformed expression tree. If not, return NULL. * * NB: argument is expected to be transformed already, ie, not a RangeVar. */ static Node * ParseComplexProjection(ParseState *pstate, char *funcname, Node *first_arg) { Oid argtype = exprType(first_arg); Oid argrelid; AttrNumber attnum; FieldSelect *fselect; argrelid = typeidTypeRelid(argtype); if (!argrelid) return NULL; /* probably should not happen */ attnum = get_attnum(argrelid, funcname); if (attnum == InvalidAttrNumber) return NULL; /* funcname does not match any column */ /* * Check for special cases where we don't want to return a FieldSelect. */ switch (nodeTag(first_arg)) { case T_Var: { Var *var = (Var *) first_arg; /* * If the Var is a whole-row tuple, we can just replace it * with a simple Var reference. */ if (var->varattno == InvalidAttrNumber) { Oid vartype; int32 vartypmod; get_atttypetypmod(argrelid, attnum, &vartype, &vartypmod); return (Node *) makeVar(var->varno, attnum, vartype, vartypmod, var->varlevelsup); } break; } default: break; } /* Else generate a FieldSelect expression */ fselect = setup_field_select(first_arg, funcname, argrelid); return (Node *) fselect; } /* * Simple helper routine for delivering "No such attribute" error message */ static void unknown_attribute(const char *schemaname, const char *relname, const char *attname) { if (schemaname) elog(ERROR, "No such attribute %s.%s.%s", schemaname, relname, attname); else elog(ERROR, "No such attribute %s.%s", relname, attname); } /* * Error message when function lookup fails that gives details of the * argument types */ void func_error(const char *caller, List *funcname, int nargs, const Oid *argtypes, const char *msg) { StringInfoData argbuf; int i; initStringInfo(&argbuf); for (i = 0; i < nargs; i++) { if (i) appendStringInfo(&argbuf, ", "); if (OidIsValid(argtypes[i])) appendStringInfo(&argbuf, format_type_be(argtypes[i])); else appendStringInfo(&argbuf, "opaque"); } if (caller == NULL) { elog(ERROR, "Function %s(%s) does not exist%s%s", NameListToString(funcname), argbuf.data, ((msg != NULL) ? "\n\t" : ""), ((msg != NULL) ? msg : "")); } else { elog(ERROR, "%s: function %s(%s) does not exist%s%s", caller, NameListToString(funcname), argbuf.data, ((msg != NULL) ? "\n\t" : ""), ((msg != NULL) ? msg : "")); } } /* * find_aggregate_func * Convenience routine to check that a function exists and is an * aggregate. * * Note: basetype is InvalidOid if we are looking for an aggregate on * all types. */ Oid find_aggregate_func(const char *caller, List *aggname, Oid basetype) { Oid oid; HeapTuple ftup; Form_pg_proc pform; oid = LookupFuncName(aggname, 1, &basetype); if (!OidIsValid(oid)) { if (basetype == InvalidOid) elog(ERROR, "%s: aggregate %s(*) does not exist", caller, NameListToString(aggname)); else elog(ERROR, "%s: aggregate %s(%s) does not exist", caller, NameListToString(aggname), format_type_be(basetype)); } /* Make sure it's an aggregate */ ftup = SearchSysCache(PROCOID, ObjectIdGetDatum(oid), 0, 0, 0); if (!HeapTupleIsValid(ftup)) /* should not happen */ elog(ERROR, "function %u not found", oid); pform = (Form_pg_proc) GETSTRUCT(ftup); if (!pform->proisagg) { if (basetype == InvalidOid) elog(ERROR, "%s: function %s(*) is not an aggregate", caller, NameListToString(aggname)); else elog(ERROR, "%s: function %s(%s) is not an aggregate", caller, NameListToString(aggname), format_type_be(basetype)); } ReleaseSysCache(ftup); return oid; } /* * LookupFuncName * Given a possibly-qualified function name and a set of argument types, * look up the function. Returns InvalidOid if no such function. * * If the function name is not schema-qualified, it is sought in the current * namespace search path. */ Oid LookupFuncName(List *funcname, int nargs, const Oid *argtypes) { FuncCandidateList clist; clist = FuncnameGetCandidates(funcname, nargs); while (clist) { if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0) return clist->oid; clist = clist->next; } return InvalidOid; } /* * LookupFuncNameTypeNames * Like LookupFuncName, but the argument types are specified by a * list of TypeName nodes. Also, if we fail to find the function * and caller is not NULL, then an error is reported via func_error. * * "opaque" is accepted as a typename only if opaqueOK is true. */ Oid LookupFuncNameTypeNames(List *funcname, List *argtypes, bool opaqueOK, const char *caller) { Oid funcoid; Oid argoids[FUNC_MAX_ARGS]; int argcount; int i; MemSet(argoids, 0, FUNC_MAX_ARGS * sizeof(Oid)); argcount = length(argtypes); if (argcount > FUNC_MAX_ARGS) elog(ERROR, "functions cannot have more than %d arguments", FUNC_MAX_ARGS); for (i = 0; i < argcount; i++) { TypeName *t = (TypeName *) lfirst(argtypes); argoids[i] = LookupTypeName(t); if (!OidIsValid(argoids[i])) { char *typnam = TypeNameToString(t); if (opaqueOK && strcmp(typnam, "opaque") == 0) argoids[i] = InvalidOid; else elog(ERROR, "Type \"%s\" does not exist", typnam); } argtypes = lnext(argtypes); } funcoid = LookupFuncName(funcname, argcount, argoids); if (!OidIsValid(funcoid) && caller != NULL) func_error(caller, funcname, argcount, argoids, NULL); return funcoid; }