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postgresql/src/backend/parser/parse_func.c

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/*-------------------------------------------------------------------------
*
* parse_func.c
* handle function calls in parser
*
* Portions Copyright (c) 1996-2013, 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_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_coerce.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"
static Oid FuncNameAsType(List *funcname);
static Node *ParseComplexProjection(ParseState *pstate, char *funcname,
Node *first_arg, int location);
/*
* 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. Conversely
* a function of a single complex-type argument can be written like a
* column reference, allowing functions to act like computed columns.
*
* 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 or variadic decoration.
* Also, when is_column is true, we return NULL on failure rather than
* reporting a no-such-function error.
*
* The argument expressions (in fargs) and filter must have been transformed
* already. But the agg_order expressions, if any, have not been.
*/
Node *
ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
List *agg_order, Expr *agg_filter,
bool agg_star, bool agg_distinct, bool func_variadic,
WindowDef *over, bool is_column, int location)
{
Oid rettype;
Oid funcid;
ListCell *l;
ListCell *nextl;
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;
/*
* 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. We can't use foreach() because we
* may modify the list ...
*/
nargs = 0;
for (l = list_head(fargs); l != NULL; l = nextl)
{
Node *arg = lfirst(l);
Oid argtype = exprType(arg);
nextl = lnext(l);
if (argtype == VOIDOID && IsA(arg, Param) &&!is_column)
{
fargs = list_delete_ptr(fargs, arg);
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);
}
/*
* 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 or variadic decoration, nor an argument name.
*/
if (nargs == 1 && agg_order == NIL && agg_filter == NULL && !agg_star &&
!agg_distinct && over == NULL && !func_variadic && argnames == NIL &&
list_length(funcname) == 1)
{
Oid argtype = actual_arg_types[0];
if (argtype == RECORDOID || ISCOMPLEX(argtype))
{
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.
*/
}
}
/*
* Okay, it's not a column projection, so it must really be a function.
* 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.
*/
fdresult = func_get_detail(funcname, fargs, argnames, nargs,
actual_arg_types,
!func_variadic, true,
&funcid, &rettype, &retset,
&nvargs, &vatype,
&declared_arg_types, &argdefaults);
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_NORMAL)
{
/*
* Normal function found; was there anything indicating it must be an
* aggregate?
*/
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_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)));
}
else if (!(fdresult == FUNCDETAIL_AGGREGATE ||
fdresult == FUNCDETAIL_WINDOWFUNC))
{
/*
* Oops. Time to die.
*
* If we are dealing with the attribute notation rel.function, let the
* caller handle failure.
*/
if (is_column)
return NULL;
/*
* Else generate a detailed complaint for a function
*/
if (fdresult == FUNCDETAIL_MULTIPLE)
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 if (list_length(agg_order) > 1)
{
/* 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
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 it's a variadic function call, transform the last nvargs arguments
* into an array --- unless it's an "any" variadic.
*/
if (nvargs > 0 && declared_arg_types[nargs - 1] != 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);
}
/*
* When function is called with an explicit VARIADIC labeled parameter,
* and the declared_arg_type is "any", then sanity check the actual
* parameter type now - it must be an array.
*/
if (nargs > 0 && vatype == ANYOID && func_variadic)
{
Oid va_arr_typid = actual_arg_types[nargs - 1];
if (!OidIsValid(get_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)))));
}
/* build the appropriate output structure */
if (fdresult == FUNCDETAIL_NORMAL)
{
FuncExpr *funcexpr = makeNode(FuncExpr);
funcexpr->funcid = funcid;
funcexpr->funcresulttype = rettype;
funcexpr->funcretset = retset;
funcexpr->funcvariadic = func_variadic;
funcexpr->funcformat = COERCE_EXPLICIT_CALL;
/* 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 */
/* args, aggorder, aggdistinct will be set by transformAggregateCall */
aggref->aggfilter = agg_filter;
aggref->aggstar = agg_star;
aggref->aggvariadic = func_variadic;
/* agglevelsup will be set by transformAggregateCall */
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)
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);
/*
* True window functions must be called with a window definition.
*/
if (!over)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("window function call requires an OVER clause"),
parser_errposition(pstate, location)));
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)));
/*
* Reject window functions which are not aggregates in the case of
* FILTER.
*/
if (!wfunc->winagg && agg_filter)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("FILTER is not implemented in non-aggregate window functions"),
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)));
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;
}
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,
&current_category,
&current_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,
&current_category,
&current_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,
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;
*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);
/*
* 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 (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;
*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,
&current_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 = (List *) stringToNode(str);
Assert(IsA(defaults, List));
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 = pform->pronargs - 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;
while (ndelete-- > 0)
defaults = list_delete_first(defaults);
*argdefaults = defaults;
}
}
if (pform->proisagg)
result = FUNCDETAIL_AGGREGATE;
else if (pform->proiswindow)
result = FUNCDETAIL_WINDOWFUNC;
else
result = FUNCDETAIL_NORMAL;
ReleaseSysCache(ftup);
return result;
}
return FUNCDETAIL_NOTFOUND;
}
/*
* 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;
typtup = LookupTypeName(NULL, makeTypeNameFromNameList(funcname), NULL);
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, 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)
{
RangeTblEntry *rte;
rte = GetRTEByRangeTablePosn(pstate,
((Var *) first_arg)->varno,
((Var *) first_arg)->varlevelsup);
/* Return a Var if funcname matches a column, else NULL */
return scanRTEForColumn(pstate, rte, funcname, location);
}
/*
* Else do it the hard way with get_expr_result_type().
*
* 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_type.
* That task is handled by expandRecordVariable().
*/
if (IsA(first_arg, Var) &&
((Var *) first_arg)->vartype == RECORDOID)
tupdesc = expandRecordVariable(pstate, (Var *) first_arg, 0);
else if (get_expr_result_type(first_arg, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
return NULL; /* unresolvable RECORD type */
Assert(tupdesc);
for (i = 0; i < tupdesc->natts; i++)
{
Form_pg_attribute att = tupdesc->attrs[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(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);
}
/*
* LookupFuncName
* Given a possibly-qualified function name and a set of argument types,
* look up the function.
*
* 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 noError is true,
* else raise an error.
*/
Oid
LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
{
FuncCandidateList clist;
clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false);
while (clist)
{
if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0)
return clist->oid;
clist = clist->next;
}
if (!noError)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("function %s does not exist",
func_signature_string(funcname, nargs,
NIL, argtypes))));
return InvalidOid;
}
/*
* LookupTypeNameOid
* Convenience routine to look up a type, silently accepting shell types
*/
static Oid
LookupTypeNameOid(const TypeName *typename)
{
Oid result;
Type typtup;
typtup = LookupTypeName(NULL, typename, NULL);
if (typtup == NULL)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type \"%s\" does not exist",
TypeNameToString(typename))));
result = typeTypeId(typtup);
ReleaseSysCache(typtup);
return result;
}
/*
* LookupFuncNameTypeNames
* Like LookupFuncName, but the argument types are specified by a
* list of TypeName nodes.
*/
Oid
LookupFuncNameTypeNames(List *funcname, List *argtypes, bool noError)
{
Oid argoids[FUNC_MAX_ARGS];
int argcount;
int i;
ListCell *args_item;
argcount = list_length(argtypes);
if (argcount > FUNC_MAX_ARGS)
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)));
args_item = list_head(argtypes);
for (i = 0; i < argcount; i++)
{
TypeName *t = (TypeName *) lfirst(args_item);
argoids[i] = LookupTypeNameOid(t);
args_item = lnext(args_item);
}
return LookupFuncName(funcname, argcount, argoids, noError);
}
/*
* LookupAggNameTypeNames
* Find an aggregate function given a name and list of TypeName nodes.
*
* This is almost like LookupFuncNameTypeNames, but the error messages refer
* to aggregates rather than plain functions, and we verify that the found
* function really is an aggregate.
*/
Oid
LookupAggNameTypeNames(List *aggname, List *argtypes, bool noError)
{
Oid argoids[FUNC_MAX_ARGS];
int argcount;
int i;
ListCell *lc;
Oid oid;
HeapTuple ftup;
Form_pg_proc pform;
argcount = list_length(argtypes);
if (argcount > FUNC_MAX_ARGS)
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)));
i = 0;
foreach(lc, argtypes)
{
TypeName *t = (TypeName *) lfirst(lc);
argoids[i] = LookupTypeNameOid(t);
i++;
}
oid = LookupFuncName(aggname, argcount, argoids, true);
if (!OidIsValid(oid))
{
if (noError)
return InvalidOid;
if (argcount == 0)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("aggregate %s(*) does not exist",
NameListToString(aggname))));
else
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("aggregate %s does not exist",
func_signature_string(aggname, argcount,
NIL, argoids))));
}
/* Make sure it's an aggregate */
ftup = SearchSysCache1(PROCOID, ObjectIdGetDatum(oid));
if (!HeapTupleIsValid(ftup)) /* should not happen */
elog(ERROR, "cache lookup failed for function %u", oid);
pform = (Form_pg_proc) GETSTRUCT(ftup);
if (!pform->proisagg)
{
ReleaseSysCache(ftup);
if (noError)
return InvalidOid;
/* we do not use the (*) notation for functions... */
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("function %s is not an aggregate",
func_signature_string(aggname, argcount,
NIL, argoids))));
}
ReleaseSysCache(ftup);
return oid;
}
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