Hi list,
Per Tom's request, I split out this refactoring from my CacheExpr patch.
Basically I'm just centralizing the eval_const_expressions_mutator()
call on function arguments, from multiple different places to a single
location. Without this, it would be a lot harder to implement argument
caching logic in the CacheExpr patch.
The old call tree goes like:
case T_FuncExpr:
-> eval_const_expressions_mutator(args)
-> simplify_function
-> reorder_function_arguments
-> eval_const_expressions_mutator(args)
-> add_function_defaults
-> eval_const_expressions_mutator(args)
New call tree:
case T_FuncExpr:
-> simplify_function
-> simplify_copy_function_arguments
-> reorder_function_arguments
-> add_function_defaults
-> eval_const_expressions_mutator(args)
Assumptions being made:
* The code didn't depend on expanding existing arguments before adding defaults
* operator calls don't need to expand default arguments -- it's
currently impossible to CREATE OPERATOR with a function that has
unspecified arguments
Other changes:
* simplify_function no longer needs a 'bool has_named_args' argument
(it finds out itself).
* I added 'bool mutate_args' in its place, since some callers need to
mutate args beforehand.
* reorder_function_arguments no longer needs to keep track of which
default args were added.
Regards,
Marti
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
new file mode 100644
index cd3da46..9485e95
*** a/src/backend/optimizer/util/clauses.c
--- b/src/backend/optimizer/util/clauses.c
*************** static List *simplify_and_arguments(List
*** 109,124 ****
static Node *simplify_boolean_equality(Oid opno, List *args);
static Expr *simplify_function(Expr *oldexpr, Oid funcid,
Oid result_type, int32 result_typmod, Oid result_collid,
! Oid input_collid, List **args,
! bool has_named_args,
! bool allow_inline,
eval_const_expressions_context *context);
static List *reorder_function_arguments(List *args, Oid result_type,
! HeapTuple func_tuple,
! eval_const_expressions_context *context);
static List *add_function_defaults(List *args, Oid result_type,
! HeapTuple func_tuple,
! eval_const_expressions_context *context);
static List *fetch_function_defaults(HeapTuple func_tuple);
static void recheck_cast_function_args(List *args, Oid result_type,
HeapTuple func_tuple);
--- 109,123 ----
static Node *simplify_boolean_equality(Oid opno, List *args);
static Expr *simplify_function(Expr *oldexpr, Oid funcid,
Oid result_type, int32 result_typmod, Oid result_collid,
! Oid input_collid, List **args_p,
! bool mutate_args, bool allow_inline,
eval_const_expressions_context *context);
+ static List *simplify_copy_function_arguments(List *old_args, Oid result_type,
+ HeapTuple func_tuple);
static List *reorder_function_arguments(List *args, Oid result_type,
! HeapTuple func_tuple);
static List *add_function_defaults(List *args, Oid result_type,
! HeapTuple func_tuple);
static List *fetch_function_defaults(HeapTuple func_tuple);
static void recheck_cast_function_args(List *args, Oid result_type,
HeapTuple func_tuple);
*************** eval_const_expressions_mutator(Node *nod
*** 2303,2336 ****
case T_FuncExpr:
{
FuncExpr *expr = (FuncExpr *) node;
! List *args;
! bool has_named_args;
Expr *simple;
FuncExpr *newexpr;
- ListCell *lc;
-
- /*
- * Reduce constants in the FuncExpr's arguments, and check to
- * see if there are any named args.
- */
- args = NIL;
- has_named_args = false;
- foreach(lc, expr->args)
- {
- Node *arg = (Node *) lfirst(lc);
-
- arg = eval_const_expressions_mutator(arg, context);
- if (IsA(arg, NamedArgExpr))
- has_named_args = true;
- args = lappend(args, arg);
- }
/*
* Code for op/func reduction is pretty bulky, so split it out
* as a separate function. Note: exprTypmod normally returns
* -1 for a FuncExpr, but not when the node is recognizably a
* length coercion; we want to preserve the typmod in the
! * eventual Const if so.
*/
simple = simplify_function((Expr *) expr,
expr->funcid,
--- 2302,2318 ----
case T_FuncExpr:
{
FuncExpr *expr = (FuncExpr *) node;
! List *args = expr->args;
Expr *simple;
FuncExpr *newexpr;
/*
* Code for op/func reduction is pretty bulky, so split it out
* as a separate function. Note: exprTypmod normally returns
* -1 for a FuncExpr, but not when the node is recognizably a
* length coercion; we want to preserve the typmod in the
! * eventual Const if so. This function also mutates the
! * argument list.
*/
simple = simplify_function((Expr *) expr,
expr->funcid,
*************** eval_const_expressions_mutator(Node *nod
*** 2339,2345 ****
expr->funccollid,
expr->inputcollid,
&args,
! has_named_args,
true,
context);
if (simple) /* successfully simplified it */
--- 2321,2327 ----
expr->funccollid,
expr->inputcollid,
&args,
! true,
true,
context);
if (simple) /* successfully simplified it */
*************** eval_const_expressions_mutator(Node *nod
*** 2365,2385 ****
case T_OpExpr:
{
OpExpr *expr = (OpExpr *) node;
! List *args;
Expr *simple;
OpExpr *newexpr;
/*
- * Reduce constants in the OpExpr's arguments. We know args
- * is either NIL or a List node, so we can call
- * expression_tree_mutator directly rather than recursing to
- * self.
- */
- args = (List *) expression_tree_mutator((Node *) expr->args,
- eval_const_expressions_mutator,
- (void *) context);
-
- /*
* Need to get OID of underlying function. Okay to scribble
* on input to this extent.
*/
--- 2347,2357 ----
case T_OpExpr:
{
OpExpr *expr = (OpExpr *) node;
! List *args = expr->args;
Expr *simple;
OpExpr *newexpr;
/*
* Need to get OID of underlying function. Okay to scribble
* on input to this extent.
*/
*************** eval_const_expressions_mutator(Node *nod
*** 2387,2393 ****
/*
* Code for op/func reduction is pretty bulky, so split it out
! * as a separate function.
*/
simple = simplify_function((Expr *) expr,
expr->opfuncid,
--- 2359,2366 ----
/*
* Code for op/func reduction is pretty bulky, so split it out
! * as a separate function. This function also mutates the
! * argument list.
*/
simple = simplify_function((Expr *) expr,
expr->opfuncid,
*************** eval_const_expressions_mutator(Node *nod
*** 2395,2401 ****
expr->opcollid,
expr->inputcollid,
&args,
! false, true, context);
if (simple) /* successfully simplified it */
return (Node *) simple;
--- 2368,2374 ----
expr->opcollid,
expr->inputcollid,
&args,
! true, true, context);
if (simple) /* successfully simplified it */
return (Node *) simple;
*************** eval_const_expressions_mutator(Node *nod
*** 2668,2674 ****
case T_CoerceViaIO:
{
CoerceViaIO *expr = (CoerceViaIO *) node;
- Expr *arg;
List *args;
Oid outfunc;
bool outtypisvarlena;
--- 2641,2646 ----
*************** eval_const_expressions_mutator(Node *nod
*** 2677,2688 ****
Expr *simple;
CoerceViaIO *newexpr;
! /*
! * Reduce constants in the CoerceViaIO's argument.
! */
! arg = (Expr *) eval_const_expressions_mutator((Node *) expr->arg,
! context);
! args = list_make1(arg);
/*
* CoerceViaIO represents calling the source type's output
--- 2649,2655 ----
Expr *simple;
CoerceViaIO *newexpr;
! args = list_make1(expr->arg);
/*
* CoerceViaIO represents calling the source type's output
*************** eval_const_expressions_mutator(Node *nod
*** 2693,2710 ****
* Note that the coercion functions are assumed not to care
* about input collation, so we just pass InvalidOid for that.
*/
! getTypeOutputInfo(exprType((Node *) arg),
&outfunc, &outtypisvarlena);
getTypeInputInfo(expr->resulttype,
&infunc, &intypioparam);
simple = simplify_function(NULL,
outfunc,
CSTRINGOID, -1,
InvalidOid,
InvalidOid,
&args,
! false, true, context);
if (simple) /* successfully simplified output fn */
{
/*
--- 2660,2678 ----
* Note that the coercion functions are assumed not to care
* about input collation, so we just pass InvalidOid for that.
*/
! getTypeOutputInfo(exprType((Node *) expr->arg),
&outfunc, &outtypisvarlena);
getTypeInputInfo(expr->resulttype,
&infunc, &intypioparam);
+ /* Mutate the argument and try to simplify */
simple = simplify_function(NULL,
outfunc,
CSTRINGOID, -1,
InvalidOid,
InvalidOid,
&args,
! true, true, context);
if (simple) /* successfully simplified output fn */
{
/*
*************** eval_const_expressions_mutator(Node *nod
*** 2745,2751 ****
* possibly-simplified argument.
*/
newexpr = makeNode(CoerceViaIO);
! newexpr->arg = arg;
newexpr->resulttype = expr->resulttype;
newexpr->resultcollid = expr->resultcollid;
newexpr->coerceformat = expr->coerceformat;
--- 2713,2719 ----
* possibly-simplified argument.
*/
newexpr = makeNode(CoerceViaIO);
! newexpr->arg = linitial(args);
newexpr->resulttype = expr->resulttype;
newexpr->resultcollid = expr->resultcollid;
newexpr->coerceformat = expr->coerceformat;
*************** simplify_boolean_equality(Oid opno, List
*** 3584,3590 ****
* Inputs are the original expression (can be NULL), function OID, actual
* result type OID (which is needed for polymorphic functions), result typmod,
* result collation, the input collation to use for the function, the
! * pre-simplified argument list, and some flags; also the context data for
* eval_const_expressions. In common cases, several of the arguments could be
* derived from the original expression. Sending them separately avoids
* duplicating NodeTag-specific knowledge, and it's necessary for CoerceViaIO.
--- 3552,3558 ----
* Inputs are the original expression (can be NULL), function OID, actual
* result type OID (which is needed for polymorphic functions), result typmod,
* result collation, the input collation to use for the function, the
! * un-simplified argument list, and some flags; also the context data for
* eval_const_expressions. In common cases, several of the arguments could be
* derived from the original expression. Sending them separately avoids
* duplicating NodeTag-specific knowledge, and it's necessary for CoerceViaIO.
*************** simplify_boolean_equality(Oid opno, List
*** 3603,3615 ****
static Expr *
simplify_function(Expr *oldexpr, Oid funcid,
Oid result_type, int32 result_typmod, Oid result_collid,
! Oid input_collid, List **args,
! bool has_named_args,
! bool allow_inline,
eval_const_expressions_context *context)
{
HeapTuple func_tuple;
Expr *newexpr;
Oid transform;
/*
--- 3571,3584 ----
static Expr *
simplify_function(Expr *oldexpr, Oid funcid,
Oid result_type, int32 result_typmod, Oid result_collid,
! Oid input_collid, List **args_p,
! bool mutate_args, bool allow_inline,
eval_const_expressions_context *context)
{
HeapTuple func_tuple;
Expr *newexpr;
+ ListCell *lc;
+ List *args = *args_p;
Oid transform;
/*
*************** simplify_function(Expr *oldexpr, Oid fun
*** 3624,3641 ****
if (!HeapTupleIsValid(func_tuple))
elog(ERROR, "cache lookup failed for function %u", funcid);
! /*
! * While we have the tuple, reorder named arguments and add default
! * arguments if needed.
! */
! if (has_named_args)
! *args = reorder_function_arguments(*args, result_type, func_tuple,
! context);
! else if (((Form_pg_proc) GETSTRUCT(func_tuple))->pronargs > list_length(*args))
! *args = add_function_defaults(*args, result_type, func_tuple, context);
newexpr = evaluate_function(funcid, result_type, result_typmod,
! result_collid, input_collid, *args,
func_tuple, context);
/*
--- 3593,3622 ----
if (!HeapTupleIsValid(func_tuple))
elog(ERROR, "cache lookup failed for function %u", funcid);
! if (mutate_args)
! {
! if (oldexpr && IsA(oldexpr, FuncExpr))
! /*
! * Reorder named arguments and add defaults if needed. Returns a
! * copied list, so we can mutate it later.
! */
! args = simplify_copy_function_arguments(args, result_type, func_tuple);
! else
! /* Copy argument list before we start mutating it. */
! args = list_copy(args);
!
! /* Reduce constants in the expression's arguments */
! foreach(lc, args)
! {
! Node *arg = (Node *) lfirst(lc);
!
! arg = eval_const_expressions_mutator(arg, context);
! lfirst(lc) = arg;
! }
! }
newexpr = evaluate_function(funcid, result_type, result_typmod,
! result_collid, input_collid, args,
func_tuple, context);
/*
*************** simplify_function(Expr *oldexpr, Oid fun
*** 3674,3702 ****
if (!newexpr && allow_inline)
newexpr = inline_function(funcid, result_type, result_collid,
! input_collid, *args,
func_tuple, context);
ReleaseSysCache(func_tuple);
return newexpr;
}
/*
* reorder_function_arguments: convert named-notation args to positional args
*
* This function also inserts default argument values as needed, since it's
* impossible to form a truly valid positional call without that.
*/
static List *
! reorder_function_arguments(List *args, Oid result_type, HeapTuple func_tuple,
! eval_const_expressions_context *context)
{
Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
int pronargs = funcform->pronargs;
int nargsprovided = list_length(args);
Node *argarray[FUNC_MAX_ARGS];
- Bitmapset *defargnumbers;
ListCell *lc;
int i;
--- 3655,3734 ----
if (!newexpr && allow_inline)
newexpr = inline_function(funcid, result_type, result_collid,
! input_collid, args,
func_tuple, context);
ReleaseSysCache(func_tuple);
+ /* Argument processing done, give it back to the caller */
+ *args_p = args;
+
return newexpr;
}
/*
+ * This function converts a named-notation argument list into positional
+ * notation while adding any needed default argument expressions
+ *
+ * A copy of the argument list is returned, the original is not modified.
+ */
+ static List *
+ simplify_copy_function_arguments(List *old_args, Oid result_type,
+ HeapTuple func_tuple)
+ {
+ List *args = NIL;
+ ListCell *lc;
+ bool has_named_args = false;
+ int args_before;
+
+ /* Do we need to reorder named arguments? */
+ foreach(lc, old_args)
+ {
+ Node *arg = (Node *) lfirst(lc);
+
+ if (IsA(arg, NamedArgExpr))
+ {
+ has_named_args = true;
+ break;
+ }
+ }
+
+ args_before = list_length(old_args);
+
+ if (has_named_args)
+ {
+ /* Reorder named arguments and add default arguments if needed. */
+ args = reorder_function_arguments(old_args, result_type, func_tuple);
+ }
+ else
+ {
+ args = list_copy(old_args);
+
+ /* Append missing default arguments to the list */
+ if (((Form_pg_proc) GETSTRUCT(func_tuple))->pronargs > list_length(args))
+ args = add_function_defaults(args, result_type, func_tuple);
+ }
+
+ /* If we added any default args, they may need casts */
+ if (list_length(args) != args_before)
+ recheck_cast_function_args(args, result_type, func_tuple);
+
+ return args;
+ }
+
+ /*
* reorder_function_arguments: convert named-notation args to positional args
*
* This function also inserts default argument values as needed, since it's
* impossible to form a truly valid positional call without that.
*/
static List *
! reorder_function_arguments(List *args, Oid result_type, HeapTuple func_tuple)
{
Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
int pronargs = funcform->pronargs;
int nargsprovided = list_length(args);
Node *argarray[FUNC_MAX_ARGS];
ListCell *lc;
int i;
*************** reorder_function_arguments(List *args, O
*** 3730,3736 ****
* Fetch default expressions, if needed, and insert into array at proper
* locations (they aren't necessarily consecutive or all used)
*/
- defargnumbers = NULL;
if (nargsprovided < pronargs)
{
List *defaults = fetch_function_defaults(func_tuple);
--- 3762,3767 ----
*************** reorder_function_arguments(List *args, O
*** 3739,3748 ****
foreach(lc, defaults)
{
if (argarray[i] == NULL)
- {
argarray[i] = (Node *) lfirst(lc);
- defargnumbers = bms_add_member(defargnumbers, i);
- }
i++;
}
}
--- 3770,3776 ----
*************** reorder_function_arguments(List *args, O
*** 3755,3786 ****
args = lappend(args, argarray[i]);
}
- /* Recheck argument types and add casts if needed */
- recheck_cast_function_args(args, result_type, func_tuple);
-
- /*
- * Lastly, we have to recursively simplify the defaults we just added (but
- * don't recurse on the args passed in, as we already did those). This
- * isn't merely an optimization, it's *necessary* since there could be
- * functions with named or defaulted arguments down in there.
- *
- * Note that we do this last in hopes of simplifying any typecasts that
- * were added by recheck_cast_function_args --- there shouldn't be any new
- * casts added to the explicit arguments, but casts on the defaults are
- * possible.
- */
- if (defargnumbers != NULL)
- {
- i = 0;
- foreach(lc, args)
- {
- if (bms_is_member(i, defargnumbers))
- lfirst(lc) = eval_const_expressions_mutator((Node *) lfirst(lc),
- context);
- i++;
- }
- }
-
return args;
}
--- 3783,3788 ----
*************** reorder_function_arguments(List *args, O
*** 3791,3810 ****
* and so we know we just need to add defaults at the end.
*/
static List *
! add_function_defaults(List *args, Oid result_type, HeapTuple func_tuple,
! eval_const_expressions_context *context)
{
Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
- int nargsprovided = list_length(args);
List *defaults;
int ndelete;
- ListCell *lc;
/* Get all the default expressions from the pg_proc tuple */
defaults = fetch_function_defaults(func_tuple);
/* Delete any unused defaults from the list */
! ndelete = nargsprovided + list_length(defaults) - funcform->pronargs;
if (ndelete < 0)
elog(ERROR, "not enough default arguments");
while (ndelete-- > 0)
--- 3793,3809 ----
* and so we know we just need to add defaults at the end.
*/
static List *
! add_function_defaults(List *args, Oid result_type, HeapTuple func_tuple)
{
Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
List *defaults;
int ndelete;
/* Get all the default expressions from the pg_proc tuple */
defaults = fetch_function_defaults(func_tuple);
/* Delete any unused defaults from the list */
! ndelete = list_length(args) + list_length(defaults) - funcform->pronargs;
if (ndelete < 0)
elog(ERROR, "not enough default arguments");
while (ndelete-- > 0)
*************** add_function_defaults(List *args, Oid re
*** 3813,3840 ****
/* And form the combined argument list */
args = list_concat(args, defaults);
- /* Recheck argument types and add casts if needed */
- recheck_cast_function_args(args, result_type, func_tuple);
-
- /*
- * Lastly, we have to recursively simplify the defaults we just added (but
- * don't recurse on the args passed in, as we already did those). This
- * isn't merely an optimization, it's *necessary* since there could be
- * functions with named or defaulted arguments down in there.
- *
- * Note that we do this last in hopes of simplifying any typecasts that
- * were added by recheck_cast_function_args --- there shouldn't be any new
- * casts added to the explicit arguments, but casts on the defaults are
- * possible.
- */
- foreach(lc, args)
- {
- if (nargsprovided-- > 0)
- continue; /* skip original arg positions */
- lfirst(lc) = eval_const_expressions_mutator((Node *) lfirst(lc),
- context);
- }
-
return args;
}
--- 3812,3817 ----
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