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Diffstat (limited to 'src/backend/parser/parse_func.c')
| -rw-r--r-- | src/backend/parser/parse_func.c | 2679 |
1 files changed, 2679 insertions, 0 deletions
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c new file mode 100644 index 0000000..542f916 --- /dev/null +++ b/src/backend/parser/parse_func.c @@ -0,0 +1,2679 @@ +/*------------------------------------------------------------------------- + * + * parse_func.c + * handle function calls in parser + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/parser/parse_func.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/htup_details.h" +#include "catalog/pg_aggregate.h" +#include "catalog/pg_proc.h" +#include "catalog/pg_type.h" +#include "funcapi.h" +#include "lib/stringinfo.h" +#include "nodes/makefuncs.h" +#include "nodes/nodeFuncs.h" +#include "parser/parse_agg.h" +#include "parser/parse_clause.h" +#include "parser/parse_coerce.h" +#include "parser/parse_expr.h" +#include "parser/parse_func.h" +#include "parser/parse_relation.h" +#include "parser/parse_target.h" +#include "parser/parse_type.h" +#include "utils/builtins.h" +#include "utils/lsyscache.h" +#include "utils/syscache.h" + + +/* Possible error codes from LookupFuncNameInternal */ +typedef enum +{ + FUNCLOOKUP_NOSUCHFUNC, + FUNCLOOKUP_AMBIGUOUS +} FuncLookupError; + +static void unify_hypothetical_args(ParseState *pstate, + List *fargs, int numAggregatedArgs, + Oid *actual_arg_types, Oid *declared_arg_types); +static Oid FuncNameAsType(List *funcname); +static Node *ParseComplexProjection(ParseState *pstate, const char *funcname, + Node *first_arg, int location); +static Oid LookupFuncNameInternal(ObjectType objtype, List *funcname, + int nargs, const Oid *argtypes, + bool include_out_arguments, bool missing_ok, + FuncLookupError *lookupError); + + +/* + * 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 can interpret it as a column projection. + * Conversely a function of a single complex-type argument can be written + * like a column reference, allowing functions to act like computed columns. + * + * If both interpretations are possible, we prefer the one matching the + * syntactic form, but otherwise the form does not matter. + * + * Hence, both cases come through here. If fn is null, we're dealing with + * column syntax not function syntax. In the function-syntax case, + * the FuncCall struct is needed to carry various decoration that applies + * to aggregate and window functions. + * + * Also, when fn is null, we return NULL on failure rather than + * reporting a no-such-function error. + * + * The argument expressions (in fargs) must have been transformed + * already. However, nothing in *fn has been transformed. + * + * last_srf should be a copy of pstate->p_last_srf from just before we + * started transforming fargs. If the caller knows that fargs couldn't + * contain any SRF calls, last_srf can just be pstate->p_last_srf. + * + * proc_call is true if we are considering a CALL statement, so that the + * name must resolve to a procedure name, not anything else. This flag + * also specifies that the argument list includes any OUT-mode arguments. + */ +Node * +ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs, + Node *last_srf, FuncCall *fn, bool proc_call, int location) +{ + bool is_column = (fn == NULL); + List *agg_order = (fn ? fn->agg_order : NIL); + Expr *agg_filter = NULL; + WindowDef *over = (fn ? fn->over : NULL); + bool agg_within_group = (fn ? fn->agg_within_group : false); + bool agg_star = (fn ? fn->agg_star : false); + bool agg_distinct = (fn ? fn->agg_distinct : false); + bool func_variadic = (fn ? fn->func_variadic : false); + CoercionForm funcformat = (fn ? fn->funcformat : COERCE_EXPLICIT_CALL); + bool could_be_projection; + Oid rettype; + Oid funcid; + ListCell *l; + Node *first_arg = NULL; + int nargs; + int nargsplusdefs; + Oid actual_arg_types[FUNC_MAX_ARGS]; + Oid *declared_arg_types; + List *argnames; + List *argdefaults; + Node *retval; + bool retset; + int nvargs; + Oid vatype; + FuncDetailCode fdresult; + char aggkind = 0; + ParseCallbackState pcbstate; + + /* + * If there's an aggregate filter, transform it using transformWhereClause + */ + if (fn && fn->agg_filter != NULL) + agg_filter = (Expr *) transformWhereClause(pstate, fn->agg_filter, + EXPR_KIND_FILTER, + "FILTER"); + + /* + * 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 (list_length(fargs) > FUNC_MAX_ARGS) + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ARGUMENTS), + errmsg_plural("cannot pass more than %d argument to a function", + "cannot pass more than %d arguments to a function", + FUNC_MAX_ARGS, + FUNC_MAX_ARGS), + parser_errposition(pstate, location))); + + /* + * Extract arg type info in preparation for function lookup. + * + * If any arguments are Param markers of type VOID, we discard them from + * the parameter list. This is a hack to allow the JDBC driver to not have + * to distinguish "input" and "output" parameter symbols while parsing + * function-call constructs. Don't do this if dealing with column syntax, + * nor if we had WITHIN GROUP (because in that case it's critical to keep + * the argument count unchanged). + */ + nargs = 0; + foreach(l, fargs) + { + Node *arg = lfirst(l); + Oid argtype = exprType(arg); + + if (argtype == VOIDOID && IsA(arg, Param) && + !is_column && !agg_within_group) + { + fargs = foreach_delete_current(fargs, l); + continue; + } + + actual_arg_types[nargs++] = argtype; + } + + /* + * Check for named arguments; if there are any, build a list of names. + * + * We allow mixed notation (some named and some not), but only with all + * the named parameters after all the unnamed ones. So the name list + * corresponds to the last N actual parameters and we don't need any extra + * bookkeeping to match things up. + */ + argnames = NIL; + foreach(l, fargs) + { + Node *arg = lfirst(l); + + if (IsA(arg, NamedArgExpr)) + { + NamedArgExpr *na = (NamedArgExpr *) arg; + ListCell *lc; + + /* Reject duplicate arg names */ + foreach(lc, argnames) + { + if (strcmp(na->name, (char *) lfirst(lc)) == 0) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("argument name \"%s\" used more than once", + na->name), + parser_errposition(pstate, na->location))); + } + argnames = lappend(argnames, na->name); + } + else + { + if (argnames != NIL) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("positional argument cannot follow named argument"), + parser_errposition(pstate, exprLocation(arg)))); + } + } + + if (fargs) + { + first_arg = linitial(fargs); + Assert(first_arg != NULL); + } + + /* + * Decide whether it's legitimate to consider the construct to be a column + * projection. For that, there has to be a single argument of complex + * type, the function name must not be qualified, and there cannot be any + * syntactic decoration that'd require it to be a function (such as + * aggregate or variadic decoration, or named arguments). + */ + could_be_projection = (nargs == 1 && !proc_call && + agg_order == NIL && agg_filter == NULL && + !agg_star && !agg_distinct && over == NULL && + !func_variadic && argnames == NIL && + list_length(funcname) == 1 && + (actual_arg_types[0] == RECORDOID || + ISCOMPLEX(actual_arg_types[0]))); + + /* + * If it's column syntax, check for column projection case first. + */ + if (could_be_projection && is_column) + { + retval = ParseComplexProjection(pstate, + strVal(linitial(funcname)), + first_arg, + location); + if (retval) + return retval; + + /* + * If ParseComplexProjection doesn't recognize it as a projection, + * just press on. + */ + } + + /* + * 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. + * + * Note: for a named-notation or variadic function call, the reported + * "true" types aren't really what is in pg_proc: the types are reordered + * to match the given argument order of named arguments, and a variadic + * argument is replaced by a suitable number of copies of its element + * type. We'll fix up the variadic case below. We may also have to deal + * with default arguments. + */ + + setup_parser_errposition_callback(&pcbstate, pstate, location); + + fdresult = func_get_detail(funcname, fargs, argnames, nargs, + actual_arg_types, + !func_variadic, true, proc_call, + &funcid, &rettype, &retset, + &nvargs, &vatype, + &declared_arg_types, &argdefaults); + + cancel_parser_errposition_callback(&pcbstate); + + /* + * Check for various wrong-kind-of-routine cases. + */ + + /* If this is a CALL, reject things that aren't procedures */ + if (proc_call && + (fdresult == FUNCDETAIL_NORMAL || + fdresult == FUNCDETAIL_AGGREGATE || + fdresult == FUNCDETAIL_WINDOWFUNC || + fdresult == FUNCDETAIL_COERCION)) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s is not a procedure", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint("To call a function, use SELECT."), + parser_errposition(pstate, location))); + /* Conversely, if not a CALL, reject procedures */ + if (fdresult == FUNCDETAIL_PROCEDURE && !proc_call) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s is a procedure", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint("To call a procedure, use CALL."), + parser_errposition(pstate, location))); + + if (fdresult == FUNCDETAIL_NORMAL || + fdresult == FUNCDETAIL_PROCEDURE || + fdresult == FUNCDETAIL_COERCION) + { + /* + * In these cases, complain if there was anything indicating it must + * be an aggregate or window function. + */ + if (agg_star) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s(*) specified, but %s is not an aggregate function", + NameListToString(funcname), + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (agg_distinct) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("DISTINCT specified, but %s is not an aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (agg_within_group) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("WITHIN GROUP specified, but %s is not an aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (agg_order != NIL) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("ORDER BY specified, but %s is not an aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (agg_filter) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("FILTER specified, but %s is not an aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (over) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("OVER specified, but %s is not a window function nor an aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + } + + /* + * So far so good, so do some fdresult-type-specific processing. + */ + if (fdresult == FUNCDETAIL_NORMAL || fdresult == FUNCDETAIL_PROCEDURE) + { + /* Nothing special to do for these cases. */ + } + else if (fdresult == FUNCDETAIL_AGGREGATE) + { + /* + * It's an aggregate; fetch needed info from the pg_aggregate entry. + */ + HeapTuple tup; + Form_pg_aggregate classForm; + int catDirectArgs; + + tup = SearchSysCache1(AGGFNOID, ObjectIdGetDatum(funcid)); + if (!HeapTupleIsValid(tup)) /* should not happen */ + elog(ERROR, "cache lookup failed for aggregate %u", funcid); + classForm = (Form_pg_aggregate) GETSTRUCT(tup); + aggkind = classForm->aggkind; + catDirectArgs = classForm->aggnumdirectargs; + ReleaseSysCache(tup); + + /* Now check various disallowed cases. */ + if (AGGKIND_IS_ORDERED_SET(aggkind)) + { + int numAggregatedArgs; + int numDirectArgs; + + if (!agg_within_group) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("WITHIN GROUP is required for ordered-set aggregate %s", + NameListToString(funcname)), + parser_errposition(pstate, location))); + if (over) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("OVER is not supported for ordered-set aggregate %s", + NameListToString(funcname)), + parser_errposition(pstate, location))); + /* gram.y rejects DISTINCT + WITHIN GROUP */ + Assert(!agg_distinct); + /* gram.y rejects VARIADIC + WITHIN GROUP */ + Assert(!func_variadic); + + /* + * Since func_get_detail was working with an undifferentiated list + * of arguments, it might have selected an aggregate that doesn't + * really match because it requires a different division of direct + * and aggregated arguments. Check that the number of direct + * arguments is actually OK; if not, throw an "undefined function" + * error, similarly to the case where a misplaced ORDER BY is used + * in a regular aggregate call. + */ + numAggregatedArgs = list_length(agg_order); + numDirectArgs = nargs - numAggregatedArgs; + Assert(numDirectArgs >= 0); + + if (!OidIsValid(vatype)) + { + /* Test is simple if aggregate isn't variadic */ + if (numDirectArgs != catDirectArgs) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint_plural("There is an ordered-set aggregate %s, but it requires %d direct argument, not %d.", + "There is an ordered-set aggregate %s, but it requires %d direct arguments, not %d.", + catDirectArgs, + NameListToString(funcname), + catDirectArgs, numDirectArgs), + parser_errposition(pstate, location))); + } + else + { + /* + * If it's variadic, we have two cases depending on whether + * the agg was "... ORDER BY VARIADIC" or "..., VARIADIC ORDER + * BY VARIADIC". It's the latter if catDirectArgs equals + * pronargs; to save a catalog lookup, we reverse-engineer + * pronargs from the info we got from func_get_detail. + */ + int pronargs; + + pronargs = nargs; + if (nvargs > 1) + pronargs -= nvargs - 1; + if (catDirectArgs < pronargs) + { + /* VARIADIC isn't part of direct args, so still easy */ + if (numDirectArgs != catDirectArgs) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint_plural("There is an ordered-set aggregate %s, but it requires %d direct argument, not %d.", + "There is an ordered-set aggregate %s, but it requires %d direct arguments, not %d.", + catDirectArgs, + NameListToString(funcname), + catDirectArgs, numDirectArgs), + parser_errposition(pstate, location))); + } + else + { + /* + * Both direct and aggregated args were declared variadic. + * For a standard ordered-set aggregate, it's okay as long + * as there aren't too few direct args. For a + * hypothetical-set aggregate, we assume that the + * hypothetical arguments are those that matched the + * variadic parameter; there must be just as many of them + * as there are aggregated arguments. + */ + if (aggkind == AGGKIND_HYPOTHETICAL) + { + if (nvargs != 2 * numAggregatedArgs) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint("To use the hypothetical-set aggregate %s, the number of hypothetical direct arguments (here %d) must match the number of ordering columns (here %d).", + NameListToString(funcname), + nvargs - numAggregatedArgs, numAggregatedArgs), + parser_errposition(pstate, location))); + } + else + { + if (nvargs <= numAggregatedArgs) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, + argnames, + actual_arg_types)), + errhint_plural("There is an ordered-set aggregate %s, but it requires at least %d direct argument.", + "There is an ordered-set aggregate %s, but it requires at least %d direct arguments.", + catDirectArgs, + NameListToString(funcname), + catDirectArgs), + parser_errposition(pstate, location))); + } + } + } + + /* Check type matching of hypothetical arguments */ + if (aggkind == AGGKIND_HYPOTHETICAL) + unify_hypothetical_args(pstate, fargs, numAggregatedArgs, + actual_arg_types, declared_arg_types); + } + else + { + /* Normal aggregate, so it can't have WITHIN GROUP */ + if (agg_within_group) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s is not an ordered-set aggregate, so it cannot have WITHIN GROUP", + NameListToString(funcname)), + parser_errposition(pstate, location))); + } + } + else if (fdresult == FUNCDETAIL_WINDOWFUNC) + { + /* + * True window functions must be called with a window definition. + */ + if (!over) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("window function %s requires an OVER clause", + NameListToString(funcname)), + parser_errposition(pstate, location))); + /* And, per spec, WITHIN GROUP isn't allowed */ + if (agg_within_group) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("window function %s cannot have WITHIN GROUP", + NameListToString(funcname)), + parser_errposition(pstate, location))); + } + else if (fdresult == FUNCDETAIL_COERCION) + { + /* + * We interpreted it as a type coercion. coerce_type can handle these + * cases, so why duplicate code... + */ + return coerce_type(pstate, linitial(fargs), + actual_arg_types[0], rettype, -1, + COERCION_EXPLICIT, COERCE_EXPLICIT_CALL, location); + } + else if (fdresult == FUNCDETAIL_MULTIPLE) + { + /* + * We found multiple possible functional matches. If we are dealing + * with attribute notation, return failure, letting the caller report + * "no such column" (we already determined there wasn't one). If + * dealing with function notation, report "ambiguous function", + * regardless of whether there's also a column by this name. + */ + if (is_column) + return NULL; + + if (proc_call) + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("procedure %s is not unique", + func_signature_string(funcname, nargs, argnames, + actual_arg_types)), + errhint("Could not choose a best candidate procedure. " + "You might need to add explicit type casts."), + parser_errposition(pstate, location))); + else + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("function %s is not unique", + func_signature_string(funcname, nargs, argnames, + actual_arg_types)), + errhint("Could not choose a best candidate function. " + "You might need to add explicit type casts."), + parser_errposition(pstate, location))); + } + else + { + /* + * Not found as a function. If we are dealing with attribute + * notation, return failure, letting the caller report "no such + * column" (we already determined there wasn't one). + */ + if (is_column) + return NULL; + + /* + * Check for column projection interpretation, since we didn't before. + */ + if (could_be_projection) + { + retval = ParseComplexProjection(pstate, + strVal(linitial(funcname)), + first_arg, + location); + if (retval) + return retval; + } + + /* + * No function, and no column either. Since we're dealing with + * function notation, report "function does not exist". + */ + if (list_length(agg_order) > 1 && !agg_within_group) + { + /* It's agg(x, ORDER BY y,z) ... perhaps misplaced ORDER BY */ + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, argnames, + actual_arg_types)), + errhint("No aggregate function matches the given name and argument types. " + "Perhaps you misplaced ORDER BY; ORDER BY must appear " + "after all regular arguments of the aggregate."), + parser_errposition(pstate, location))); + } + else if (proc_call) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("procedure %s does not exist", + func_signature_string(funcname, nargs, argnames, + actual_arg_types)), + errhint("No procedure matches the given name and argument types. " + "You might need to add explicit type casts."), + parser_errposition(pstate, location))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, argnames, + actual_arg_types)), + errhint("No function matches the given name and argument types. " + "You might need to add explicit type casts."), + parser_errposition(pstate, location))); + } + + /* + * If there are default arguments, we have to include their types in + * actual_arg_types for the purpose of checking generic type consistency. + * However, we do NOT put them into the generated parse node, because + * their actual values might change before the query gets run. The + * planner has to insert the up-to-date values at plan time. + */ + nargsplusdefs = nargs; + foreach(l, argdefaults) + { + Node *expr = (Node *) lfirst(l); + + /* probably shouldn't happen ... */ + if (nargsplusdefs >= FUNC_MAX_ARGS) + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ARGUMENTS), + errmsg_plural("cannot pass more than %d argument to a function", + "cannot pass more than %d arguments to a function", + FUNC_MAX_ARGS, + FUNC_MAX_ARGS), + parser_errposition(pstate, location))); + + actual_arg_types[nargsplusdefs++] = exprType(expr); + } + + /* + * enforce consistency with polymorphic argument and return types, + * possibly adjusting return type or declared_arg_types (which will be + * used as the cast destination by make_fn_arguments) + */ + rettype = enforce_generic_type_consistency(actual_arg_types, + declared_arg_types, + nargsplusdefs, + rettype, + false); + + /* perform the necessary typecasting of arguments */ + make_fn_arguments(pstate, fargs, actual_arg_types, declared_arg_types); + + /* + * If the function isn't actually variadic, forget any VARIADIC decoration + * on the call. (Perhaps we should throw an error instead, but + * historically we've allowed people to write that.) + */ + if (!OidIsValid(vatype)) + { + Assert(nvargs == 0); + func_variadic = false; + } + + /* + * If it's a variadic function call, transform the last nvargs arguments + * into an array --- unless it's an "any" variadic. + */ + if (nvargs > 0 && vatype != ANYOID) + { + ArrayExpr *newa = makeNode(ArrayExpr); + int non_var_args = nargs - nvargs; + List *vargs; + + Assert(non_var_args >= 0); + vargs = list_copy_tail(fargs, non_var_args); + fargs = list_truncate(fargs, non_var_args); + + newa->elements = vargs; + /* assume all the variadic arguments were coerced to the same type */ + newa->element_typeid = exprType((Node *) linitial(vargs)); + newa->array_typeid = get_array_type(newa->element_typeid); + if (!OidIsValid(newa->array_typeid)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("could not find array type for data type %s", + format_type_be(newa->element_typeid)), + parser_errposition(pstate, exprLocation((Node *) vargs)))); + /* array_collid will be set by parse_collate.c */ + newa->multidims = false; + newa->location = exprLocation((Node *) vargs); + + fargs = lappend(fargs, newa); + + /* We could not have had VARIADIC marking before ... */ + Assert(!func_variadic); + /* ... but now, it's a VARIADIC call */ + func_variadic = true; + } + + /* + * If an "any" variadic is called with explicit VARIADIC marking, insist + * that the variadic parameter be of some array type. + */ + if (nargs > 0 && vatype == ANYOID && func_variadic) + { + Oid va_arr_typid = actual_arg_types[nargs - 1]; + + if (!OidIsValid(get_base_element_type(va_arr_typid))) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("VARIADIC argument must be an array"), + parser_errposition(pstate, + exprLocation((Node *) llast(fargs))))); + } + + /* if it returns a set, check that's OK */ + if (retset) + check_srf_call_placement(pstate, last_srf, location); + + /* build the appropriate output structure */ + if (fdresult == FUNCDETAIL_NORMAL || fdresult == FUNCDETAIL_PROCEDURE) + { + FuncExpr *funcexpr = makeNode(FuncExpr); + + funcexpr->funcid = funcid; + funcexpr->funcresulttype = rettype; + funcexpr->funcretset = retset; + funcexpr->funcvariadic = func_variadic; + funcexpr->funcformat = funcformat; + /* funccollid and inputcollid will be set by parse_collate.c */ + funcexpr->args = fargs; + funcexpr->location = location; + + retval = (Node *) funcexpr; + } + else if (fdresult == FUNCDETAIL_AGGREGATE && !over) + { + /* aggregate function */ + Aggref *aggref = makeNode(Aggref); + + aggref->aggfnoid = funcid; + aggref->aggtype = rettype; + /* aggcollid and inputcollid will be set by parse_collate.c */ + aggref->aggtranstype = InvalidOid; /* will be set by planner */ + /* aggargtypes will be set by transformAggregateCall */ + /* aggdirectargs and args will be set by transformAggregateCall */ + /* aggorder and aggdistinct will be set by transformAggregateCall */ + aggref->aggfilter = agg_filter; + aggref->aggstar = agg_star; + aggref->aggvariadic = func_variadic; + aggref->aggkind = aggkind; + /* agglevelsup will be set by transformAggregateCall */ + aggref->aggsplit = AGGSPLIT_SIMPLE; /* planner might change this */ + aggref->aggno = -1; /* planner will set aggno and aggtransno */ + aggref->aggtransno = -1; + aggref->location = location; + + /* + * Reject attempt to call a parameterless aggregate without (*) + * syntax. This is mere pedantry but some folks insisted ... + */ + if (fargs == NIL && !agg_star && !agg_within_group) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s(*) must be used to call a parameterless aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + + if (retset) + ereport(ERROR, + (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION), + errmsg("aggregates cannot return sets"), + parser_errposition(pstate, location))); + + /* + * We might want to support named arguments later, but disallow it for + * now. We'd need to figure out the parsed representation (should the + * NamedArgExprs go above or below the TargetEntry nodes?) and then + * teach the planner to reorder the list properly. Or maybe we could + * make transformAggregateCall do that? However, if you'd also like + * to allow default arguments for aggregates, we'd need to do it in + * planning to avoid semantic problems. + */ + if (argnames != NIL) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("aggregates cannot use named arguments"), + parser_errposition(pstate, location))); + + /* parse_agg.c does additional aggregate-specific processing */ + transformAggregateCall(pstate, aggref, fargs, agg_order, agg_distinct); + + retval = (Node *) aggref; + } + else + { + /* window function */ + WindowFunc *wfunc = makeNode(WindowFunc); + + Assert(over); /* lack of this was checked above */ + Assert(!agg_within_group); /* also checked above */ + + wfunc->winfnoid = funcid; + wfunc->wintype = rettype; + /* wincollid and inputcollid will be set by parse_collate.c */ + wfunc->args = fargs; + /* winref will be set by transformWindowFuncCall */ + wfunc->winstar = agg_star; + wfunc->winagg = (fdresult == FUNCDETAIL_AGGREGATE); + wfunc->aggfilter = agg_filter; + wfunc->location = location; + + /* + * agg_star is allowed for aggregate functions but distinct isn't + */ + if (agg_distinct) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("DISTINCT is not implemented for window functions"), + parser_errposition(pstate, location))); + + /* + * Reject attempt to call a parameterless aggregate without (*) + * syntax. This is mere pedantry but some folks insisted ... + */ + if (wfunc->winagg && fargs == NIL && !agg_star) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s(*) must be used to call a parameterless aggregate function", + NameListToString(funcname)), + parser_errposition(pstate, location))); + + /* + * ordered aggs not allowed in windows yet + */ + if (agg_order != NIL) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("aggregate ORDER BY is not implemented for window functions"), + parser_errposition(pstate, location))); + + /* + * FILTER is not yet supported with true window functions + */ + if (!wfunc->winagg && agg_filter) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("FILTER is not implemented for non-aggregate window functions"), + parser_errposition(pstate, location))); + + /* + * Window functions can't either take or return sets + */ + if (pstate->p_last_srf != last_srf) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("window function calls cannot contain set-returning function calls"), + errhint("You might be able to move the set-returning function into a LATERAL FROM item."), + parser_errposition(pstate, + exprLocation(pstate->p_last_srf)))); + + if (retset) + ereport(ERROR, + (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION), + errmsg("window functions cannot return sets"), + parser_errposition(pstate, location))); + + /* parse_agg.c does additional window-func-specific processing */ + transformWindowFuncCall(pstate, wfunc, over); + + retval = (Node *) wfunc; + } + + /* if it returns a set, remember it for error checks at higher levels */ + if (retset) + pstate->p_last_srf = retval; + + return retval; +} + + +/* func_match_argtypes() + * + * Given a list of candidate functions (having the right name and number + * of arguments) and an array of input datatype OIDs, produce a shortlist of + * those candidates that actually accept the input datatypes (either exactly + * or by coercion), and return the number of such candidates. + * + * Note that can_coerce_type will assume that UNKNOWN inputs are coercible to + * anything, so candidates will not be eliminated on that basis. + * + * NB: okay to modify input list structure, as long as we find at least + * one match. If no match at all, the list must remain unmodified. + */ +int +func_match_argtypes(int nargs, + Oid *input_typeids, + FuncCandidateList raw_candidates, + FuncCandidateList *candidates) /* return value */ +{ + FuncCandidateList current_candidate; + FuncCandidateList next_candidate; + int ncandidates = 0; + + *candidates = NULL; + + for (current_candidate = raw_candidates; + current_candidate != NULL; + current_candidate = next_candidate) + { + next_candidate = current_candidate->next; + if (can_coerce_type(nargs, input_typeids, current_candidate->args, + COERCION_IMPLICIT)) + { + current_candidate->next = *candidates; + *candidates = current_candidate; + ncandidates++; + } + } + + return ncandidates; +} /* func_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. + * + * Note that the caller has already determined that there is no candidate + * exactly matching the input argtypes, and has pruned away any "candidates" + * that aren't actually coercion-compatible with the input types. + * + * This is also used for resolving ambiguous operator references. Formerly + * parse_oper.c had its own, essentially duplicate code for the purpose. + * The following comments (formerly in parse_oper.c) are kept to record some + * of the history of these heuristics. + * + * OLD COMMENTS: + * + * This routine is new code, replacing binary_oper_select_candidate() + * which dates from v4.2/v1.0.x days. It tries very hard to match up + * operators with types, including allowing type coercions if necessary. + * The important thing is that the code do as much as possible, + * while _never_ doing the wrong thing, where "the wrong thing" would + * be returning an operator when other better choices are available, + * or returning an operator which is a non-intuitive possibility. + * - thomas 1998-05-21 + * + * The comments below came from binary_oper_select_candidate(), and + * illustrate the issues and choices which are possible: + * - thomas 1998-05-20 + * + * current wisdom holds that the default operator should be one in which + * both operands have the same type (there will only be one such + * operator) + * + * 7.27.93 - I have decided not to do this; it's too hard to justify, and + * it's easy enough to typecast explicitly - avi + * [the rest of this routine was commented out since then - ay] + * + * 6/23/95 - I don't complete agree with avi. In particular, casting + * floats is a pain for users. Whatever the rationale behind not doing + * this is, I need the following special case to work. + * + * In the WHERE clause of a query, if a float is specified without + * quotes, we treat it as float8. I added the float48* operators so + * that we can operate on float4 and float8. But now we have more than + * one matching operator if the right arg is unknown (eg. float + * specified with quotes). This break some stuff in the regression + * test where there are floats in quotes not properly casted. Below is + * the solution. In addition to requiring the operator operates on the + * same type for both operands [as in the code Avi originally + * commented out], we also require that the operators be equivalent in + * some sense. (see equivalentOpersAfterPromotion for details.) + * - ay 6/95 + */ +FuncCandidateList +func_select_candidate(int nargs, + Oid *input_typeids, + FuncCandidateList candidates) +{ + FuncCandidateList current_candidate, + first_candidate, + last_candidate; + Oid *current_typeids; + Oid current_type; + int i; + int ncandidates; + int nbestMatch, + nmatch, + nunknowns; + Oid input_base_typeids[FUNC_MAX_ARGS]; + TYPCATEGORY slot_category[FUNC_MAX_ARGS], + current_category; + bool current_is_preferred; + bool slot_has_preferred_type[FUNC_MAX_ARGS]; + bool resolved_unknowns; + + /* protect local fixed-size arrays */ + if (nargs > FUNC_MAX_ARGS) + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ARGUMENTS), + errmsg_plural("cannot pass more than %d argument to a function", + "cannot pass more than %d arguments to a function", + FUNC_MAX_ARGS, + FUNC_MAX_ARGS))); + + /* + * If any input types are domains, reduce them to their base types. This + * ensures that we will consider functions on the base type to be "exact + * matches" in the exact-match heuristic; it also makes it possible to do + * something useful with the type-category heuristics. Note that this + * makes it difficult, but not impossible, to use functions declared to + * take a domain as an input datatype. Such a function will be selected + * over the base-type function only if it is an exact match at all + * argument positions, and so was already chosen by our caller. + * + * While we're at it, count the number of unknown-type arguments for use + * later. + */ + nunknowns = 0; + for (i = 0; i < nargs; i++) + { + if (input_typeids[i] != UNKNOWNOID) + input_base_typeids[i] = getBaseType(input_typeids[i]); + else + { + /* no need to call getBaseType on UNKNOWNOID */ + input_base_typeids[i] = UNKNOWNOID; + nunknowns++; + } + } + + /* + * 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_base_typeids[i] != UNKNOWNOID && + current_typeids[i] == input_base_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 have either + * exact matches or preferred types at the args that will require + * coercion. (Restriction added in 7.4: preferred type must be of same + * category as input type; give no preference to cross-category + * conversions to preferred types.) Keep all candidates if none match. + */ + for (i = 0; i < nargs; i++) /* avoid multiple lookups */ + slot_category[i] = TypeCategory(input_base_typeids[i]); + 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_base_typeids[i] != UNKNOWNOID) + { + if (current_typeids[i] == input_base_typeids[i] || + IsPreferredType(slot_category[i], 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 inputs. + * + * If there are no unknown inputs, we have no more heuristics that apply, + * and must fail. + */ + if (nunknowns == 0) + return NULL; /* failed to select a best candidate */ + + /* + * The next step examines 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 just one candidate remains, return + * that one. However, if this rule turns out to reject all candidates, + * keep them all instead. + */ + resolved_unknowns = false; + for (i = 0; i < nargs; i++) + { + bool have_conflict; + + if (input_base_typeids[i] != UNKNOWNOID) + continue; + resolved_unknowns = true; /* assume we can do it */ + slot_category[i] = TYPCATEGORY_INVALID; + 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]; + get_type_category_preferred(current_type, + ¤t_category, + ¤t_is_preferred); + if (slot_category[i] == TYPCATEGORY_INVALID) + { + /* first candidate */ + slot_category[i] = current_category; + slot_has_preferred_type[i] = current_is_preferred; + } + else if (current_category == slot_category[i]) + { + /* more candidates in same category */ + slot_has_preferred_type[i] |= current_is_preferred; + } + else + { + /* category conflict! */ + if (current_category == TYPCATEGORY_STRING) + { + /* STRING always wins if available */ + slot_category[i] = current_category; + slot_has_preferred_type[i] = current_is_preferred; + } + else + { + /* + * Remember conflict, but keep going (might find STRING) + */ + have_conflict = true; + } + } + } + if (have_conflict && slot_category[i] != TYPCATEGORY_STRING) + { + /* Failed to resolve category conflict at this position */ + resolved_unknowns = false; + break; + } + } + + if (resolved_unknowns) + { + /* Strip non-matching candidates */ + ncandidates = 0; + first_candidate = candidates; + 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_base_typeids[i] != UNKNOWNOID) + continue; + current_type = current_typeids[i]; + get_type_category_preferred(current_type, + ¤t_category, + ¤t_is_preferred); + if (current_category != slot_category[i]) + { + keepit = false; + break; + } + if (slot_has_preferred_type[i] && !current_is_preferred) + { + 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 + first_candidate = current_candidate->next; + } + } + + /* if we found any matches, restrict our attention to those */ + if (last_candidate) + { + candidates = first_candidate; + /* terminate rebuilt list */ + last_candidate->next = NULL; + } + + if (ncandidates == 1) + return candidates; + } + + /* + * Last gasp: if there are both known- and unknown-type inputs, and all + * the known types are the same, assume the unknown inputs are also that + * type, and see if that gives us a unique match. If so, use that match. + * + * NOTE: for a binary operator with one unknown and one non-unknown input, + * we already tried this heuristic in binary_oper_exact(). However, that + * code only finds exact matches, whereas here we will handle matches that + * involve coercion, polymorphic type resolution, etc. + */ + if (nunknowns < nargs) + { + Oid known_type = UNKNOWNOID; + + for (i = 0; i < nargs; i++) + { + if (input_base_typeids[i] == UNKNOWNOID) + continue; + if (known_type == UNKNOWNOID) /* first known arg? */ + known_type = input_base_typeids[i]; + else if (known_type != input_base_typeids[i]) + { + /* oops, not all match */ + known_type = UNKNOWNOID; + break; + } + } + + if (known_type != UNKNOWNOID) + { + /* okay, just one known type, apply the heuristic */ + for (i = 0; i < nargs; i++) + input_base_typeids[i] = known_type; + ncandidates = 0; + last_candidate = NULL; + for (current_candidate = candidates; + current_candidate != NULL; + current_candidate = current_candidate->next) + { + current_typeids = current_candidate->args; + if (can_coerce_type(nargs, input_base_typeids, current_typeids, + COERCION_IMPLICIT)) + { + if (++ncandidates > 1) + break; /* not unique, give up */ + last_candidate = current_candidate; + } + } + if (ncandidates == 1) + { + /* successfully identified a unique match */ + last_candidate->next = NULL; + return last_candidate; + } + } + } + + return NULL; /* failed to select a best 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 type coercion request + * 2) apply the ambiguous-function resolution rules + * + * Return values *funcid through *true_typeids receive info about the function. + * If argdefaults isn't NULL, *argdefaults receives a list of any default + * argument expressions that need to be added to the given arguments. + * + * When processing a named- or mixed-notation call (ie, fargnames isn't NIL), + * the returned true_typeids and argdefaults are ordered according to the + * call's argument ordering: first any positional arguments, then the named + * arguments, then defaulted arguments (if needed and allowed by + * expand_defaults). Some care is needed if this information is to be compared + * to the function's pg_proc entry, but in practice the caller can usually + * just work with the call's argument ordering. + * + * We rely primarily on fargnames/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 need that check made. Note also that when fargnames isn't NIL, + * the fargs list must be passed if the caller wants actual argument position + * information to be returned into the NamedArgExpr nodes. + */ +FuncDetailCode +func_get_detail(List *funcname, + List *fargs, + List *fargnames, + int nargs, + Oid *argtypes, + bool expand_variadic, + bool expand_defaults, + bool include_out_arguments, + Oid *funcid, /* return value */ + Oid *rettype, /* return value */ + bool *retset, /* return value */ + int *nvargs, /* return value */ + Oid *vatype, /* return value */ + Oid **true_typeids, /* return value */ + List **argdefaults) /* optional return value */ +{ + FuncCandidateList raw_candidates; + FuncCandidateList best_candidate; + + /* initialize output arguments to silence compiler warnings */ + *funcid = InvalidOid; + *rettype = InvalidOid; + *retset = false; + *nvargs = 0; + *vatype = InvalidOid; + *true_typeids = NULL; + if (argdefaults) + *argdefaults = NIL; + + /* Get list of possible candidates from namespace search */ + raw_candidates = FuncnameGetCandidates(funcname, nargs, fargnames, + expand_variadic, expand_defaults, + include_out_arguments, false); + + /* + * Quickly check if there is an exact match to the input datatypes (there + * can be only one) + */ + for (best_candidate = raw_candidates; + best_candidate != NULL; + best_candidate = best_candidate->next) + { + /* if nargs==0, argtypes can be null; don't pass that to memcmp */ + if (nargs == 0 || + 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 the coercion path is RELABELTYPE or COERCEVIAIO, 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 simple coercion, not as + * "text(name(varchar))" which the code below this point is entirely + * capable of selecting. + * + * We also treat a coercion of a previously-unknown-type literal + * constant to a specific type this way. + * + * The reason we reject COERCION_PATH_FUNC here is that we expect the + * cast implementation function to be named after the target type. + * Thus the function will be found by normal lookup if appropriate. + * + * The reason we reject COERCION_PATH_ARRAYCOERCE is mainly that you + * can't write "foo[] (something)" as a function call. In theory + * someone might want to invoke it as "_foo (something)" but we have + * never supported that historically, so we can insist that people + * write it as a normal cast instead. + * + * We also reject the specific case of COERCEVIAIO for a composite + * source type and a string-category target type. This is a case that + * find_coercion_pathway() allows by default, but experience has shown + * that it's too commonly invoked by mistake. So, again, insist that + * people use cast syntax if they want to do that. + * + * NB: it's important that this code does not exceed 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 && fargnames == NIL) + { + Oid targetType = FuncNameAsType(funcname); + + if (OidIsValid(targetType)) + { + Oid sourceType = argtypes[0]; + Node *arg1 = linitial(fargs); + bool iscoercion; + + if (sourceType == UNKNOWNOID && IsA(arg1, Const)) + { + /* always treat typename('literal') as coercion */ + iscoercion = true; + } + else + { + CoercionPathType cpathtype; + Oid cfuncid; + + cpathtype = find_coercion_pathway(targetType, sourceType, + COERCION_EXPLICIT, + &cfuncid); + switch (cpathtype) + { + case COERCION_PATH_RELABELTYPE: + iscoercion = true; + break; + case COERCION_PATH_COERCEVIAIO: + if ((sourceType == RECORDOID || + ISCOMPLEX(sourceType)) && + TypeCategory(targetType) == TYPCATEGORY_STRING) + iscoercion = false; + else + iscoercion = true; + break; + default: + iscoercion = false; + break; + } + } + + if (iscoercion) + { + /* Treat it as a type coercion */ + *funcid = InvalidOid; + *rettype = targetType; + *retset = false; + *nvargs = 0; + *vatype = InvalidOid; + *true_typeids = argtypes; + return FUNCDETAIL_COERCION; + } + } + } + + /* + * didn't find an exact match, so now try to match up candidates... + */ + if (raw_candidates != NULL) + { + FuncCandidateList current_candidates; + int ncandidates; + + ncandidates = func_match_argtypes(nargs, + argtypes, + raw_candidates, + ¤t_candidates); + + /* one match only? then run with it... */ + if (ncandidates == 1) + best_candidate = current_candidates; + + /* + * multiple candidates? then better decide or throw an error... + */ + else if (ncandidates > 1) + { + best_candidate = func_select_candidate(nargs, + argtypes, + current_candidates); + + /* + * If we were able to choose a best candidate, we're done. + * Otherwise, ambiguous function call. + */ + if (!best_candidate) + return FUNCDETAIL_MULTIPLE; + } + } + } + + if (best_candidate) + { + HeapTuple ftup; + Form_pg_proc pform; + FuncDetailCode result; + + /* + * If processing named args or expanding variadics or defaults, the + * "best candidate" might represent multiple equivalently good + * functions; treat this case as ambiguous. + */ + if (!OidIsValid(best_candidate->oid)) + return FUNCDETAIL_MULTIPLE; + + /* + * We disallow VARIADIC with named arguments unless the last argument + * (the one with VARIADIC attached) actually matched the variadic + * parameter. This is mere pedantry, really, but some folks insisted. + */ + if (fargnames != NIL && !expand_variadic && nargs > 0 && + best_candidate->argnumbers[nargs - 1] != nargs - 1) + return FUNCDETAIL_NOTFOUND; + + *funcid = best_candidate->oid; + *nvargs = best_candidate->nvargs; + *true_typeids = best_candidate->args; + + /* + * If processing named args, return actual argument positions into + * NamedArgExpr nodes in the fargs list. This is a bit ugly but not + * worth the extra notation needed to do it differently. + */ + if (best_candidate->argnumbers != NULL) + { + int i = 0; + ListCell *lc; + + foreach(lc, fargs) + { + NamedArgExpr *na = (NamedArgExpr *) lfirst(lc); + + if (IsA(na, NamedArgExpr)) + na->argnumber = best_candidate->argnumbers[i]; + i++; + } + } + + ftup = SearchSysCache1(PROCOID, + ObjectIdGetDatum(best_candidate->oid)); + if (!HeapTupleIsValid(ftup)) /* should not happen */ + elog(ERROR, "cache lookup failed for function %u", + best_candidate->oid); + pform = (Form_pg_proc) GETSTRUCT(ftup); + *rettype = pform->prorettype; + *retset = pform->proretset; + *vatype = pform->provariadic; + /* fetch default args if caller wants 'em */ + if (argdefaults && best_candidate->ndargs > 0) + { + Datum proargdefaults; + bool isnull; + char *str; + List *defaults; + + /* shouldn't happen, FuncnameGetCandidates messed up */ + if (best_candidate->ndargs > pform->pronargdefaults) + elog(ERROR, "not enough default arguments"); + + proargdefaults = SysCacheGetAttr(PROCOID, ftup, + Anum_pg_proc_proargdefaults, + &isnull); + Assert(!isnull); + str = TextDatumGetCString(proargdefaults); + defaults = castNode(List, stringToNode(str)); + pfree(str); + + /* Delete any unused defaults from the returned list */ + if (best_candidate->argnumbers != NULL) + { + /* + * This is a bit tricky in named notation, since the supplied + * arguments could replace any subset of the defaults. We + * work by making a bitmapset of the argnumbers of defaulted + * arguments, then scanning the defaults list and selecting + * the needed items. (This assumes that defaulted arguments + * should be supplied in their positional order.) + */ + Bitmapset *defargnumbers; + int *firstdefarg; + List *newdefaults; + ListCell *lc; + int i; + + defargnumbers = NULL; + firstdefarg = &best_candidate->argnumbers[best_candidate->nargs - best_candidate->ndargs]; + for (i = 0; i < best_candidate->ndargs; i++) + defargnumbers = bms_add_member(defargnumbers, + firstdefarg[i]); + newdefaults = NIL; + i = best_candidate->nominalnargs - pform->pronargdefaults; + foreach(lc, defaults) + { + if (bms_is_member(i, defargnumbers)) + newdefaults = lappend(newdefaults, lfirst(lc)); + i++; + } + Assert(list_length(newdefaults) == best_candidate->ndargs); + bms_free(defargnumbers); + *argdefaults = newdefaults; + } + else + { + /* + * Defaults for positional notation are lots easier; just + * remove any unwanted ones from the front. + */ + int ndelete; + + ndelete = list_length(defaults) - best_candidate->ndargs; + if (ndelete > 0) + defaults = list_delete_first_n(defaults, ndelete); + *argdefaults = defaults; + } + } + + switch (pform->prokind) + { + case PROKIND_AGGREGATE: + result = FUNCDETAIL_AGGREGATE; + break; + case PROKIND_FUNCTION: + result = FUNCDETAIL_NORMAL; + break; + case PROKIND_PROCEDURE: + result = FUNCDETAIL_PROCEDURE; + break; + case PROKIND_WINDOW: + result = FUNCDETAIL_WINDOWFUNC; + break; + default: + elog(ERROR, "unrecognized prokind: %c", pform->prokind); + result = FUNCDETAIL_NORMAL; /* keep compiler quiet */ + break; + } + + ReleaseSysCache(ftup); + return result; + } + + return FUNCDETAIL_NOTFOUND; +} + + +/* + * unify_hypothetical_args() + * + * Ensure that each hypothetical direct argument of a hypothetical-set + * aggregate has the same type as the corresponding aggregated argument. + * Modify the expressions in the fargs list, if necessary, and update + * actual_arg_types[]. + * + * If the agg declared its args non-ANY (even ANYELEMENT), we need only a + * sanity check that the declared types match; make_fn_arguments will coerce + * the actual arguments to match the declared ones. But if the declaration + * is ANY, nothing will happen in make_fn_arguments, so we need to fix any + * mismatch here. We use the same type resolution logic as UNION etc. + */ +static void +unify_hypothetical_args(ParseState *pstate, + List *fargs, + int numAggregatedArgs, + Oid *actual_arg_types, + Oid *declared_arg_types) +{ + int numDirectArgs, + numNonHypotheticalArgs; + int hargpos; + + numDirectArgs = list_length(fargs) - numAggregatedArgs; + numNonHypotheticalArgs = numDirectArgs - numAggregatedArgs; + /* safety check (should only trigger with a misdeclared agg) */ + if (numNonHypotheticalArgs < 0) + elog(ERROR, "incorrect number of arguments to hypothetical-set aggregate"); + + /* Check each hypothetical arg and corresponding aggregated arg */ + for (hargpos = numNonHypotheticalArgs; hargpos < numDirectArgs; hargpos++) + { + int aargpos = numDirectArgs + (hargpos - numNonHypotheticalArgs); + ListCell *harg = list_nth_cell(fargs, hargpos); + ListCell *aarg = list_nth_cell(fargs, aargpos); + Oid commontype; + int32 commontypmod; + + /* A mismatch means AggregateCreate didn't check properly ... */ + if (declared_arg_types[hargpos] != declared_arg_types[aargpos]) + elog(ERROR, "hypothetical-set aggregate has inconsistent declared argument types"); + + /* No need to unify if make_fn_arguments will coerce */ + if (declared_arg_types[hargpos] != ANYOID) + continue; + + /* + * Select common type, giving preference to the aggregated argument's + * type (we'd rather coerce the direct argument once than coerce all + * the aggregated values). + */ + commontype = select_common_type(pstate, + list_make2(lfirst(aarg), lfirst(harg)), + "WITHIN GROUP", + NULL); + commontypmod = select_common_typmod(pstate, + list_make2(lfirst(aarg), lfirst(harg)), + commontype); + + /* + * Perform the coercions. We don't need to worry about NamedArgExprs + * here because they aren't supported with aggregates. + */ + lfirst(harg) = coerce_type(pstate, + (Node *) lfirst(harg), + actual_arg_types[hargpos], + commontype, commontypmod, + COERCION_IMPLICIT, + COERCE_IMPLICIT_CAST, + -1); + actual_arg_types[hargpos] = commontype; + lfirst(aarg) = coerce_type(pstate, + (Node *) lfirst(aarg), + actual_arg_types[aargpos], + commontype, commontypmod, + COERCION_IMPLICIT, + COERCE_IMPLICIT_CAST, + -1); + actual_arg_types[aargpos] = commontype; + } +} + + +/* + * make_fn_arguments() + * + * Given the actual argument expressions for a function, and the desired + * input types for the function, add any necessary typecasting to the + * expression tree. Caller should already have verified that casting is + * allowed. + * + * Caution: given argument list is modified in-place. + * + * As with coerce_type, pstate may be NULL if no special unknown-Param + * processing is wanted. + */ +void +make_fn_arguments(ParseState *pstate, + List *fargs, + Oid *actual_arg_types, + Oid *declared_arg_types) +{ + ListCell *current_fargs; + int i = 0; + + foreach(current_fargs, fargs) + { + /* types don't match? then force coercion using a function call... */ + if (actual_arg_types[i] != declared_arg_types[i]) + { + Node *node = (Node *) lfirst(current_fargs); + + /* + * If arg is a NamedArgExpr, coerce its input expr instead --- we + * want the NamedArgExpr to stay at the top level of the list. + */ + if (IsA(node, NamedArgExpr)) + { + NamedArgExpr *na = (NamedArgExpr *) node; + + node = coerce_type(pstate, + (Node *) na->arg, + actual_arg_types[i], + declared_arg_types[i], -1, + COERCION_IMPLICIT, + COERCE_IMPLICIT_CAST, + -1); + na->arg = (Expr *) node; + } + else + { + node = coerce_type(pstate, + node, + actual_arg_types[i], + declared_arg_types[i], -1, + COERCION_IMPLICIT, + COERCE_IMPLICIT_CAST, + -1); + lfirst(current_fargs) = node; + } + } + i++; + } +} + +/* + * FuncNameAsType - + * convenience routine to see if a function name matches a type name + * + * Returns the OID of the matching type, or InvalidOid if none. We ignore + * shell types and complex types. + */ +static Oid +FuncNameAsType(List *funcname) +{ + Oid result; + Type typtup; + + /* + * temp_ok=false protects the <refsect1 id="sql-createfunction-security"> + * contract for writing SECURITY DEFINER functions safely. + */ + typtup = LookupTypeNameExtended(NULL, makeTypeNameFromNameList(funcname), + NULL, false, false); + if (typtup == NULL) + return InvalidOid; + + if (((Form_pg_type) GETSTRUCT(typtup))->typisdefined && + !OidIsValid(typeTypeRelid(typtup))) + result = typeTypeId(typtup); + else + result = InvalidOid; + + ReleaseSysCache(typtup); + return result; +} + +/* + * 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. + */ +static Node * +ParseComplexProjection(ParseState *pstate, const char *funcname, Node *first_arg, + int location) +{ + TupleDesc tupdesc; + int i; + + /* + * Special case for whole-row Vars so that we can resolve (foo.*).bar even + * when foo is a reference to a subselect, join, or RECORD function. A + * bonus is that we avoid generating an unnecessary FieldSelect; our + * result can omit the whole-row Var and just be a Var for the selected + * field. + * + * This case could be handled by expandRecordVariable, but it's more + * efficient to do it this way when possible. + */ + if (IsA(first_arg, Var) && + ((Var *) first_arg)->varattno == InvalidAttrNumber) + { + ParseNamespaceItem *nsitem; + + nsitem = GetNSItemByRangeTablePosn(pstate, + ((Var *) first_arg)->varno, + ((Var *) first_arg)->varlevelsup); + /* Return a Var if funcname matches a column, else NULL */ + return scanNSItemForColumn(pstate, nsitem, + ((Var *) first_arg)->varlevelsup, + funcname, location); + } + + /* + * Else do it the hard way with get_expr_result_tupdesc(). + * + * If it's a Var of type RECORD, we have to work even harder: we have to + * find what the Var refers to, and pass that to get_expr_result_tupdesc. + * That task is handled by expandRecordVariable(). + */ + if (IsA(first_arg, Var) && + ((Var *) first_arg)->vartype == RECORDOID) + tupdesc = expandRecordVariable(pstate, (Var *) first_arg, 0); + else + tupdesc = get_expr_result_tupdesc(first_arg, true); + if (!tupdesc) + return NULL; /* unresolvable RECORD type */ + + for (i = 0; i < tupdesc->natts; i++) + { + Form_pg_attribute att = TupleDescAttr(tupdesc, i); + + if (strcmp(funcname, NameStr(att->attname)) == 0 && + !att->attisdropped) + { + /* Success, so generate a FieldSelect expression */ + FieldSelect *fselect = makeNode(FieldSelect); + + fselect->arg = (Expr *) first_arg; + fselect->fieldnum = i + 1; + fselect->resulttype = att->atttypid; + fselect->resulttypmod = att->atttypmod; + /* save attribute's collation for parse_collate.c */ + fselect->resultcollid = att->attcollation; + return (Node *) fselect; + } + } + + return NULL; /* funcname does not match any column */ +} + +/* + * funcname_signature_string + * Build a string representing a function name, including arg types. + * The result is something like "foo(integer)". + * + * If argnames isn't NIL, it is a list of C strings representing the actual + * arg names for the last N arguments. This must be considered part of the + * function signature too, when dealing with named-notation function calls. + * + * This is typically used in the construction of function-not-found error + * messages. + */ +const char * +funcname_signature_string(const char *funcname, int nargs, + List *argnames, const Oid *argtypes) +{ + StringInfoData argbuf; + int numposargs; + ListCell *lc; + int i; + + initStringInfo(&argbuf); + + appendStringInfo(&argbuf, "%s(", funcname); + + numposargs = nargs - list_length(argnames); + lc = list_head(argnames); + + for (i = 0; i < nargs; i++) + { + if (i) + appendStringInfoString(&argbuf, ", "); + if (i >= numposargs) + { + appendStringInfo(&argbuf, "%s => ", (char *) lfirst(lc)); + lc = lnext(argnames, lc); + } + appendStringInfoString(&argbuf, format_type_be(argtypes[i])); + } + + appendStringInfoChar(&argbuf, ')'); + + return argbuf.data; /* return palloc'd string buffer */ +} + +/* + * func_signature_string + * As above, but function name is passed as a qualified name list. + */ +const char * +func_signature_string(List *funcname, int nargs, + List *argnames, const Oid *argtypes) +{ + return funcname_signature_string(NameListToString(funcname), + nargs, argnames, argtypes); +} + +/* + * LookupFuncNameInternal + * Workhorse for LookupFuncName/LookupFuncWithArgs + * + * In an error situation, e.g. can't find the function, then we return + * InvalidOid and set *lookupError to indicate what went wrong. + * + * Possible errors: + * FUNCLOOKUP_NOSUCHFUNC: we can't find a function of this name. + * FUNCLOOKUP_AMBIGUOUS: more than one function matches. + */ +static Oid +LookupFuncNameInternal(ObjectType objtype, List *funcname, + int nargs, const Oid *argtypes, + bool include_out_arguments, bool missing_ok, + FuncLookupError *lookupError) +{ + Oid result = InvalidOid; + FuncCandidateList clist; + + /* NULL argtypes allowed for nullary functions only */ + Assert(argtypes != NULL || nargs == 0); + + /* Always set *lookupError, to forestall uninitialized-variable warnings */ + *lookupError = FUNCLOOKUP_NOSUCHFUNC; + + /* Get list of candidate objects */ + clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false, + include_out_arguments, missing_ok); + + /* Scan list for a match to the arg types (if specified) and the objtype */ + for (; clist != NULL; clist = clist->next) + { + /* Check arg type match, if specified */ + if (nargs >= 0) + { + /* if nargs==0, argtypes can be null; don't pass that to memcmp */ + if (nargs > 0 && + memcmp(argtypes, clist->args, nargs * sizeof(Oid)) != 0) + continue; + } + + /* Check for duplicates reported by FuncnameGetCandidates */ + if (!OidIsValid(clist->oid)) + { + *lookupError = FUNCLOOKUP_AMBIGUOUS; + return InvalidOid; + } + + /* Check objtype match, if specified */ + switch (objtype) + { + case OBJECT_FUNCTION: + case OBJECT_AGGREGATE: + /* Ignore procedures */ + if (get_func_prokind(clist->oid) == PROKIND_PROCEDURE) + continue; + break; + case OBJECT_PROCEDURE: + /* Ignore non-procedures */ + if (get_func_prokind(clist->oid) != PROKIND_PROCEDURE) + continue; + break; + case OBJECT_ROUTINE: + /* no restriction */ + break; + default: + Assert(false); + } + + /* Check for multiple matches */ + if (OidIsValid(result)) + { + *lookupError = FUNCLOOKUP_AMBIGUOUS; + return InvalidOid; + } + + /* OK, we have a candidate */ + result = clist->oid; + } + + return result; +} + +/* + * LookupFuncName + * + * Given a possibly-qualified function name and optionally a set of argument + * types, look up the function. Pass nargs == -1 to indicate that the number + * and types of the arguments are unspecified (this is NOT the same as + * specifying that there are no arguments). + * + * If the function name is not schema-qualified, it is sought in the current + * namespace search path. + * + * If the function is not found, we return InvalidOid if missing_ok is true, + * else raise an error. + * + * If nargs == -1 and multiple functions are found matching this function name + * we will raise an ambiguous-function error, regardless of what missing_ok is + * set to. + * + * Only functions will be found; procedures will be ignored even if they + * match the name and argument types. (However, we don't trouble to reject + * aggregates or window functions here.) + */ +Oid +LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool missing_ok) +{ + Oid funcoid; + FuncLookupError lookupError; + + funcoid = LookupFuncNameInternal(OBJECT_FUNCTION, + funcname, nargs, argtypes, + false, missing_ok, + &lookupError); + + if (OidIsValid(funcoid)) + return funcoid; + + switch (lookupError) + { + case FUNCLOOKUP_NOSUCHFUNC: + /* Let the caller deal with it when missing_ok is true */ + if (missing_ok) + return InvalidOid; + + if (nargs < 0) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("could not find a function named \"%s\"", + NameListToString(funcname)))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(funcname, nargs, + NIL, argtypes)))); + break; + + case FUNCLOOKUP_AMBIGUOUS: + /* Raise an error regardless of missing_ok */ + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("function name \"%s\" is not unique", + NameListToString(funcname)), + errhint("Specify the argument list to select the function unambiguously."))); + break; + } + + return InvalidOid; /* Keep compiler quiet */ +} + +/* + * LookupFuncWithArgs + * + * Like LookupFuncName, but the argument types are specified by an + * ObjectWithArgs node. Also, this function can check whether the result is a + * function, procedure, or aggregate, based on the objtype argument. Pass + * OBJECT_ROUTINE to accept any of them. + * + * For historical reasons, we also accept aggregates when looking for a + * function. + * + * When missing_ok is true we don't generate any error for missing objects and + * return InvalidOid. Other types of errors can still be raised, regardless + * of the value of missing_ok. + */ +Oid +LookupFuncWithArgs(ObjectType objtype, ObjectWithArgs *func, bool missing_ok) +{ + Oid argoids[FUNC_MAX_ARGS]; + int argcount; + int nargs; + int i; + ListCell *args_item; + Oid oid; + FuncLookupError lookupError; + + Assert(objtype == OBJECT_AGGREGATE || + objtype == OBJECT_FUNCTION || + objtype == OBJECT_PROCEDURE || + objtype == OBJECT_ROUTINE); + + argcount = list_length(func->objargs); + if (argcount > FUNC_MAX_ARGS) + { + if (objtype == OBJECT_PROCEDURE) + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ARGUMENTS), + errmsg_plural("procedures cannot have more than %d argument", + "procedures cannot have more than %d arguments", + FUNC_MAX_ARGS, + FUNC_MAX_ARGS))); + else + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ARGUMENTS), + errmsg_plural("functions cannot have more than %d argument", + "functions cannot have more than %d arguments", + FUNC_MAX_ARGS, + FUNC_MAX_ARGS))); + } + + /* + * First, perform a lookup considering only input arguments (traditional + * Postgres rules). + */ + i = 0; + foreach(args_item, func->objargs) + { + TypeName *t = lfirst_node(TypeName, args_item); + + argoids[i] = LookupTypeNameOid(NULL, t, missing_ok); + if (!OidIsValid(argoids[i])) + return InvalidOid; /* missing_ok must be true */ + i++; + } + + /* + * Set nargs for LookupFuncNameInternal. It expects -1 to mean no args + * were specified. + */ + nargs = func->args_unspecified ? -1 : argcount; + + /* + * In args_unspecified mode, also tell LookupFuncNameInternal to consider + * the object type, since there seems no reason not to. However, if we + * have an argument list, disable the objtype check, because we'd rather + * complain about "object is of wrong type" than "object doesn't exist". + * (Note that with args, FuncnameGetCandidates will have ensured there's + * only one argtype match, so we're not risking an ambiguity failure via + * this choice.) + */ + oid = LookupFuncNameInternal(func->args_unspecified ? objtype : OBJECT_ROUTINE, + func->objname, nargs, argoids, + false, missing_ok, + &lookupError); + + /* + * If PROCEDURE or ROUTINE was specified, and we have an argument list + * that contains no parameter mode markers, and we didn't already discover + * that there's ambiguity, perform a lookup considering all arguments. + * (Note: for a zero-argument procedure, or in args_unspecified mode, the + * normal lookup is sufficient; so it's OK to require non-NIL objfuncargs + * to perform this lookup.) + */ + if ((objtype == OBJECT_PROCEDURE || objtype == OBJECT_ROUTINE) && + func->objfuncargs != NIL && + lookupError != FUNCLOOKUP_AMBIGUOUS) + { + bool have_param_mode = false; + + /* + * Check for non-default parameter mode markers. If there are any, + * then the command does not conform to SQL-spec syntax, so we may + * assume that the traditional Postgres lookup method of considering + * only input parameters is sufficient. (Note that because the spec + * doesn't have OUT arguments for functions, we also don't need this + * hack in FUNCTION or AGGREGATE mode.) + */ + foreach(args_item, func->objfuncargs) + { + FunctionParameter *fp = lfirst_node(FunctionParameter, args_item); + + if (fp->mode != FUNC_PARAM_DEFAULT) + { + have_param_mode = true; + break; + } + } + + if (!have_param_mode) + { + Oid poid; + + /* Without mode marks, objargs surely includes all params */ + Assert(list_length(func->objfuncargs) == argcount); + + /* For objtype == OBJECT_PROCEDURE, we can ignore non-procedures */ + poid = LookupFuncNameInternal(objtype, func->objname, + argcount, argoids, + true, missing_ok, + &lookupError); + + /* Combine results, handling ambiguity */ + if (OidIsValid(poid)) + { + if (OidIsValid(oid) && oid != poid) + { + /* oops, we got hits both ways, on different objects */ + oid = InvalidOid; + lookupError = FUNCLOOKUP_AMBIGUOUS; + } + else + oid = poid; + } + else if (lookupError == FUNCLOOKUP_AMBIGUOUS) + oid = InvalidOid; + } + } + + if (OidIsValid(oid)) + { + /* + * Even if we found the function, perform validation that the objtype + * matches the prokind of the found function. For historical reasons + * we allow the objtype of FUNCTION to include aggregates and window + * functions; but we draw the line if the object is a procedure. That + * is a new enough feature that this historical rule does not apply. + * + * (This check is partially redundant with the objtype check in + * LookupFuncNameInternal; but not entirely, since we often don't tell + * LookupFuncNameInternal to apply that check at all.) + */ + switch (objtype) + { + case OBJECT_FUNCTION: + /* Only complain if it's a procedure. */ + if (get_func_prokind(oid) == PROKIND_PROCEDURE) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s is not a function", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + + case OBJECT_PROCEDURE: + /* Reject if found object is not a procedure. */ + if (get_func_prokind(oid) != PROKIND_PROCEDURE) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("%s is not a procedure", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + + case OBJECT_AGGREGATE: + /* Reject if found object is not an aggregate. */ + if (get_func_prokind(oid) != PROKIND_AGGREGATE) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("function %s is not an aggregate", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + + default: + /* OBJECT_ROUTINE accepts anything. */ + break; + } + + return oid; /* All good */ + } + else + { + /* Deal with cases where the lookup failed */ + switch (lookupError) + { + case FUNCLOOKUP_NOSUCHFUNC: + /* Suppress no-such-func errors when missing_ok is true */ + if (missing_ok) + break; + + switch (objtype) + { + case OBJECT_PROCEDURE: + if (func->args_unspecified) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("could not find a procedure named \"%s\"", + NameListToString(func->objname)))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("procedure %s does not exist", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + + case OBJECT_AGGREGATE: + if (func->args_unspecified) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("could not find an aggregate named \"%s\"", + NameListToString(func->objname)))); + else if (argcount == 0) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("aggregate %s(*) does not exist", + NameListToString(func->objname)))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("aggregate %s does not exist", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + + default: + /* FUNCTION and ROUTINE */ + if (func->args_unspecified) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("could not find a function named \"%s\"", + NameListToString(func->objname)))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_FUNCTION), + errmsg("function %s does not exist", + func_signature_string(func->objname, argcount, + NIL, argoids)))); + break; + } + break; + + case FUNCLOOKUP_AMBIGUOUS: + switch (objtype) + { + case OBJECT_FUNCTION: + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("function name \"%s\" is not unique", + NameListToString(func->objname)), + func->args_unspecified ? + errhint("Specify the argument list to select the function unambiguously.") : 0)); + break; + case OBJECT_PROCEDURE: + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("procedure name \"%s\" is not unique", + NameListToString(func->objname)), + func->args_unspecified ? + errhint("Specify the argument list to select the procedure unambiguously.") : 0)); + break; + case OBJECT_AGGREGATE: + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("aggregate name \"%s\" is not unique", + NameListToString(func->objname)), + func->args_unspecified ? + errhint("Specify the argument list to select the aggregate unambiguously.") : 0)); + break; + case OBJECT_ROUTINE: + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_FUNCTION), + errmsg("routine name \"%s\" is not unique", + NameListToString(func->objname)), + func->args_unspecified ? + errhint("Specify the argument list to select the routine unambiguously.") : 0)); + break; + + default: + Assert(false); /* Disallowed by Assert above */ + break; + } + break; + } + + return InvalidOid; + } +} + +/* + * check_srf_call_placement + * Verify that a set-returning function is called in a valid place, + * and throw a nice error if not. + * + * A side-effect is to set pstate->p_hasTargetSRFs true if appropriate. + * + * last_srf should be a copy of pstate->p_last_srf from just before we + * started transforming the function's arguments. This allows detection + * of whether the SRF's arguments contain any SRFs. + */ +void +check_srf_call_placement(ParseState *pstate, Node *last_srf, int location) +{ + const char *err; + bool errkind; + + /* + * Check to see if the set-returning function is in an invalid place + * within the query. Basically, we don't allow SRFs anywhere except in + * the targetlist (which includes GROUP BY/ORDER BY expressions), VALUES, + * and functions in FROM. + * + * For brevity we support two schemes for reporting an error here: set + * "err" to a custom message, or set "errkind" true if the error context + * is sufficiently identified by what ParseExprKindName will return, *and* + * what it will return is just a SQL keyword. (Otherwise, use a custom + * message to avoid creating translation problems.) + */ + err = NULL; + errkind = false; + switch (pstate->p_expr_kind) + { + case EXPR_KIND_NONE: + Assert(false); /* can't happen */ + break; + case EXPR_KIND_OTHER: + /* Accept SRF here; caller must throw error if wanted */ + break; + case EXPR_KIND_JOIN_ON: + case EXPR_KIND_JOIN_USING: + err = _("set-returning functions are not allowed in JOIN conditions"); + break; + case EXPR_KIND_FROM_SUBSELECT: + /* can't get here, but just in case, throw an error */ + errkind = true; + break; + case EXPR_KIND_FROM_FUNCTION: + /* okay, but we don't allow nested SRFs here */ + /* errmsg is chosen to match transformRangeFunction() */ + /* errposition should point to the inner SRF */ + if (pstate->p_last_srf != last_srf) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("set-returning functions must appear at top level of FROM"), + parser_errposition(pstate, + exprLocation(pstate->p_last_srf)))); + break; + case EXPR_KIND_WHERE: + errkind = true; + break; + case EXPR_KIND_POLICY: + err = _("set-returning functions are not allowed in policy expressions"); + break; + case EXPR_KIND_HAVING: + errkind = true; + break; + case EXPR_KIND_FILTER: + errkind = true; + break; + case EXPR_KIND_WINDOW_PARTITION: + case EXPR_KIND_WINDOW_ORDER: + /* okay, these are effectively GROUP BY/ORDER BY */ + pstate->p_hasTargetSRFs = true; + break; + case EXPR_KIND_WINDOW_FRAME_RANGE: + case EXPR_KIND_WINDOW_FRAME_ROWS: + case EXPR_KIND_WINDOW_FRAME_GROUPS: + err = _("set-returning functions are not allowed in window definitions"); + break; + case EXPR_KIND_SELECT_TARGET: + case EXPR_KIND_INSERT_TARGET: + /* okay */ + pstate->p_hasTargetSRFs = true; + break; + case EXPR_KIND_UPDATE_SOURCE: + case EXPR_KIND_UPDATE_TARGET: + /* disallowed because it would be ambiguous what to do */ + errkind = true; + break; + case EXPR_KIND_GROUP_BY: + case EXPR_KIND_ORDER_BY: + /* okay */ + pstate->p_hasTargetSRFs = true; + break; + case EXPR_KIND_DISTINCT_ON: + /* okay */ + pstate->p_hasTargetSRFs = true; + break; + case EXPR_KIND_LIMIT: + case EXPR_KIND_OFFSET: + errkind = true; + break; + case EXPR_KIND_RETURNING: + errkind = true; + break; + case EXPR_KIND_VALUES: + /* SRFs are presently not supported by nodeValuesscan.c */ + errkind = true; + break; + case EXPR_KIND_VALUES_SINGLE: + /* okay, since we process this like a SELECT tlist */ + pstate->p_hasTargetSRFs = true; + break; + case EXPR_KIND_CHECK_CONSTRAINT: + case EXPR_KIND_DOMAIN_CHECK: + err = _("set-returning functions are not allowed in check constraints"); + break; + case EXPR_KIND_COLUMN_DEFAULT: + case EXPR_KIND_FUNCTION_DEFAULT: + err = _("set-returning functions are not allowed in DEFAULT expressions"); + break; + case EXPR_KIND_INDEX_EXPRESSION: + err = _("set-returning functions are not allowed in index expressions"); + break; + case EXPR_KIND_INDEX_PREDICATE: + err = _("set-returning functions are not allowed in index predicates"); + break; + case EXPR_KIND_STATS_EXPRESSION: + err = _("set-returning functions are not allowed in statistics expressions"); + break; + case EXPR_KIND_ALTER_COL_TRANSFORM: + err = _("set-returning functions are not allowed in transform expressions"); + break; + case EXPR_KIND_EXECUTE_PARAMETER: + err = _("set-returning functions are not allowed in EXECUTE parameters"); + break; + case EXPR_KIND_TRIGGER_WHEN: + err = _("set-returning functions are not allowed in trigger WHEN conditions"); + break; + case EXPR_KIND_PARTITION_BOUND: + err = _("set-returning functions are not allowed in partition bound"); + break; + case EXPR_KIND_PARTITION_EXPRESSION: + err = _("set-returning functions are not allowed in partition key expressions"); + break; + case EXPR_KIND_CALL_ARGUMENT: + err = _("set-returning functions are not allowed in CALL arguments"); + break; + case EXPR_KIND_COPY_WHERE: + err = _("set-returning functions are not allowed in COPY FROM WHERE conditions"); + break; + case EXPR_KIND_GENERATED_COLUMN: + err = _("set-returning functions are not allowed in column generation expressions"); + break; + case EXPR_KIND_CYCLE_MARK: + errkind = true; + break; + + /* + * There is intentionally no default: case here, so that the + * compiler will warn if we add a new ParseExprKind without + * extending this switch. If we do see an unrecognized value at + * runtime, the behavior will be the same as for EXPR_KIND_OTHER, + * which is sane anyway. + */ + } + if (err) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg_internal("%s", err), + parser_errposition(pstate, location))); + if (errkind) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + /* translator: %s is name of a SQL construct, eg GROUP BY */ + errmsg("set-returning functions are not allowed in %s", + ParseExprKindName(pstate->p_expr_kind)), + parser_errposition(pstate, location))); +} |