[C++] PATCH c++/19628 (revision 3)
Matt Austern
matt@lafstern.org
Wed Feb 2 00:41:00 GMT 2005
My earlier patch caused an ICE in some cases. This new version fixes
that problem, and includes a new test case.
OK to commit to mainline?
--Matt
* cp-tree.h (builtin_valid_in_constant_expr_p): Declare.
* parser.c (cp_parser_postfix_expression): Accept function call in
constant expression if builtin_valid_in_constant_expr_p is true for
that function.
* pt.c (value_dependent_expression_p): Handle CALL_EXPRs properly.
* semantics.c (finish_id_expression): Accept function call in constant
expression if builtin_valid_in_constant_expr_p is true for that
function.
* tree.c (builtin_valid_in_constant_expr_p): New.
* g++/ext/builtin7.C: New.
* g++/ext/builtin8.C: New.
Index: gcc/cp/cp-tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/cp-tree.h,v
retrieving revision 1.1099
diff -p -r1.1099 cp-tree.h
*** gcc/cp/cp-tree.h 31 Jan 2005 06:16:54 -0000 1.1099
--- gcc/cp/cp-tree.h 2 Feb 2005 00:33:09 -0000
*************** extern tree copy_binfo (tree, tree, t
*** 4207,4212 ****
--- 4207,4213 ----
tree *, int);
extern int member_p (tree);
extern cp_lvalue_kind real_lvalue_p (tree);
+ extern bool builtin_valid_in_constant_expr_p (tree);
extern tree build_min (enum tree_code, tree, ...);
extern tree build_min_nt (enum tree_code, ...);
extern tree build_min_non_dep (enum tree_code, tree, ...);
Index: gcc/cp/parser.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/parser.c,v
retrieving revision 1.309
diff -p -r1.309 parser.c
*** gcc/cp/parser.c 1 Feb 2005 06:58:16 -0000 1.309
--- gcc/cp/parser.c 2 Feb 2005 00:33:10 -0000
*************** cp_parser_postfix_expression (cp_parser
*** 4037,4044 ****
/* Function calls are not permitted in
constant-expressions. */
! if (cp_parser_non_integral_constant_expression (parser,
! "a function call"))
{
postfix_expression = error_mark_node;
break;
--- 4037,4045 ----
/* Function calls are not permitted in
constant-expressions. */
! if (! builtin_valid_in_constant_expr_p (postfix_expression)
! && cp_parser_non_integral_constant_expression (parser,
! "a function call"))
{
postfix_expression = error_mark_node;
break;
Index: gcc/cp/pt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/pt.c,v
retrieving revision 1.971
diff -p -r1.971 pt.c
*** gcc/cp/pt.c 1 Feb 2005 05:56:03 -0000 1.971
--- gcc/cp/pt.c 2 Feb 2005 00:33:10 -0000
*************** value_dependent_expression_p (tree expre
*** 12018,12023 ****
--- 12018,12047 ----
if (TREE_CODE (expression) == COMPONENT_REF)
return (value_dependent_expression_p (TREE_OPERAND (expression,
0))
|| value_dependent_expression_p (TREE_OPERAND (expression, 1)));
+ /* A CALL_EXPR is value-dependent if any argument is
value-dependent. */
+ if (TREE_CODE (expression) == CALL_EXPR)
+ {
+ tree function = TREE_OPERAND (expression, 0);
+ tree args = TREE_OPERAND (expression, 1);
+
+ if (value_dependent_expression_p (function))
+ return true;
+ else if (! args)
+ return false;
+ else if (TREE_CODE (args) == TREE_LIST)
+ {
+ do
+ {
+ if (value_dependent_expression_p (TREE_VALUE (args)))
+ return true;
+ args = TREE_CHAIN (args);
+ }
+ while (args);
+ return false;
+ }
+ else
+ return value_dependent_expression_p (args);
+ }
/* A constant expression is value-dependent if any subexpression is
value-dependent. */
if (EXPR_P (expression))
Index: gcc/cp/semantics.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/semantics.c,v
retrieving revision 1.459
diff -p -r1.459 semantics.c
*** gcc/cp/semantics.c 31 Jan 2005 01:16:58 -0000 1.459
--- gcc/cp/semantics.c 2 Feb 2005 00:33:10 -0000
*************** finish_id_expression (tree id_expression
*** 2663,2669 ****
expression. Enumerators and template parameters have already
been handled above. */
if (integral_constant_expression_p
! && !DECL_INTEGRAL_CONSTANT_VAR_P (decl))
{
if (!allow_non_integral_constant_expression_p)
{
--- 2663,2670 ----
expression. Enumerators and template parameters have already
been handled above. */
if (integral_constant_expression_p
! && ! DECL_INTEGRAL_CONSTANT_VAR_P (decl)
! && ! builtin_valid_in_constant_expr_p (decl))
{
if (!allow_non_integral_constant_expression_p)
{
Index: gcc/cp/tree.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/tree.c,v
retrieving revision 1.425
diff -p -r1.425 tree.c
*** gcc/cp/tree.c 18 Jan 2005 23:51:26 -0000 1.425
--- gcc/cp/tree.c 2 Feb 2005 00:33:10 -0000
*************** lvalue_p (tree ref)
*** 215,220 ****
--- 215,233 ----
(lvalue_p_1 (ref, /*class rvalue ok*/ 1) != clk_none);
}
+ /* Test whether DECL is a builtin that may appear in a
+ constant-expression. */
+
+ bool
+ builtin_valid_in_constant_expr_p (tree decl)
+ {
+ /* At present BUILT_IN_CONSTANT_P is the only builtin we're allowing
+ in constant-expressions. We may want to add other builtins
later. */
+ return TREE_CODE (decl) == FUNCTION_DECL
+ && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
+ && DECL_FUNCTION_CODE (decl) == BUILT_IN_CONSTANT_P;
+ }
+
/* Build a TARGET_EXPR, initializing the DECL with the VALUE. */
static tree
Index: gcc/testsuite/g++.dg/ext/builtin7.C
===================================================================
RCS file: gcc/testsuite/g++.dg/ext/builtin7.C
diff -N gcc/testsuite/g++.dg/ext/builtin7.C
*** /dev/null 1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/g++.dg/ext/builtin7.C 2 Feb 2005 00:33:14 -0000
***************
*** 0 ****
--- 1,14 ----
+ // PR c++/19628
+ // Verify that __builtin_constant_p may appear in a
constant-expression.
+
+ // { dg-do run }
+
+ int main()
+ {
+ switch (3) {
+ case (__builtin_constant_p(7) ? 3 : 8):
+ return 0;
+ default:
+ return 1;
+ }
+ }
Index: gcc/testsuite/g++.dg/ext/builtin8.C
===================================================================
RCS file: gcc/testsuite/g++.dg/ext/builtin8.C
diff -N gcc/testsuite/g++.dg/ext/builtin8.C
*** /dev/null 1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/g++.dg/ext/builtin8.C 2 Feb 2005 00:33:14 -0000
***************
*** 0 ****
--- 1,16 ----
+ // PR c++/19628
+ // Verify that __builtin_constant_p may appear in a
constant-expression.
+
+ // { dg-do compile }
+
+ template <int I>
+ int f(int x[__builtin_constant_p(I)])
+ {
+ return x[0];
+ }
+
+ int g()
+ {
+ int a[1] = { 7 };
+ return f<32>(a);
+ }
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