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Code review for function default parameters patch. Fix numerous problems as

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per recent discussions.  In passing this also fixes a couple of bugs in
the previous variadic-parameters patch.
This commit is contained in:
Tom Lane
2008-12-18 18:20:35 +00:00
parent cee63eab8d
commit 517ae4039e
27 changed files with 803 additions and 445 deletions
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93
src/backend/parser/parse_func.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.208 2008/12/04 17:51:26 petere Exp $
* $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.209 2008/12/18 18:20:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -71,13 +71,14 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
ListCell *nextl;
Node *first_arg = NULL;
int nargs;
int nargsplusdefs;
Oid actual_arg_types[FUNC_MAX_ARGS];
Oid *declared_arg_types;
List *argdefaults;
Node *retval;
bool retset;
int nvargs;
FuncDetailCode fdresult;
List *argdefaults;
/*
* Most of the rest of the parser just assumes that functions do not have
@ -157,13 +158,13 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
* 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. (In the case of a variadic function call, the reported
* the function. In the case of a variadic function call, the reported
* "true" types aren't really what is in pg_proc: the variadic argument is
* replaced by a suitable number of copies of its element type. We'll fix
* it up below.)
* it up below. We may also have to deal with default arguments.
*/
fdresult = func_get_detail(funcname, fargs, nargs, actual_arg_types,
!func_variadic,
!func_variadic, true,
&funcid, &rettype, &retset, &nvargs,
&declared_arg_types, &argdefaults);
if (fdresult == FUNCDETAIL_COERCION)
@ -235,21 +236,29 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
parser_errposition(pstate, location)));
}
/* add stored expressions as called values for arguments with defaults */
if (argdefaults)
/*
* 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)
{
ListCell *lc;
Node *expr = (Node *) lfirst(l);
foreach(lc, argdefaults)
{
Node *expr = (Node *) lfirst(lc);
fargs = lappend(fargs, expr);
actual_arg_types[nargs++] = exprType(expr);
}
/* probably shouldn't happen ... */
if (nargsplusdefs >= FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
errmsg("cannot pass more than %d arguments to a function",
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
@ -257,7 +266,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
*/
rettype = enforce_generic_type_consistency(actual_arg_types,
declared_arg_types,
nargs,
nargsplusdefs,
rettype,
false);
@ -741,18 +750,20 @@ func_get_detail(List *funcname,
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 **true_typeids, /* return value */
List **argdefaults) /* return value */
List **argdefaults) /* optional return value */
{
FuncCandidateList raw_candidates;
FuncCandidateList best_candidate;
/* Get list of possible candidates from namespace search */
raw_candidates = FuncnameGetCandidates(funcname, nargs, expand_variadic);
raw_candidates = FuncnameGetCandidates(funcname, nargs,
expand_variadic, expand_defaults);
/*
* Quickly check if there is an exact match to the input datatypes (there
@ -884,11 +895,17 @@ func_get_detail(List *funcname,
Form_pg_proc pform;
FuncDetailCode result;
/*
* If 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;
*funcid = best_candidate->oid;
*nvargs = best_candidate->nvargs;
*true_typeids = best_candidate->args;
if (argdefaults)
*argdefaults = best_candidate->argdefaults;
ftup = SearchSysCache(PROCOID,
ObjectIdGetDatum(best_candidate->oid),
@ -899,6 +916,38 @@ func_get_detail(List *funcname,
pform = (Form_pg_proc) GETSTRUCT(ftup);
*rettype = pform->prorettype;
*retset = pform->proretset;
/* fetch default args if caller wants 'em */
if (argdefaults)
{
if (best_candidate->ndargs > 0)
{
Datum proargdefaults;
bool isnull;
char *str;
List *defaults;
int ndelete;
/* 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 */
ndelete = list_length(defaults) - best_candidate->ndargs;
while (ndelete-- > 0)
defaults = list_delete_first(defaults);
*argdefaults = defaults;
}
else
*argdefaults = NIL;
}
result = pform->proisagg ? FUNCDETAIL_AGGREGATE : FUNCDETAIL_NORMAL;
ReleaseSysCache(ftup);
return result;
@ -1243,7 +1292,7 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
{
FuncCandidateList clist;
clist = FuncnameGetCandidates(funcname, nargs, false);
clist = FuncnameGetCandidates(funcname, nargs, false, false);
while (clist)
{