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re PR c++/65656 (__builtin_constant_p should always be constexpr)

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PR c++/65656
	* constexpr.c (cxx_eval_builtin_function_call): Fix
	__builtin_constant_p.

From-SVN: r222531
This commit is contained in:
Jason Merrill 2015-04-28 10:43:59 -04:00 • committed by Jason Merrill
parent b71983a5ba
commit 5756d0f931
3 changed files with 32 additions and 10 deletions
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4
gcc/cp/ChangeLog
View file

@ -1,5 +1,9 @@
2015-04-28 Jason Merrill <jason@redhat.com>
PR c++/65656
* constexpr.c (cxx_eval_builtin_function_call): Fix
__builtin_constant_p.
PR c++/50800
* tree.c (strip_typedefs): Add remove_attributes parm.
(strip_typedefs_expr): Likewise.

32
gcc/cp/constexpr.c
View file

@ -1014,7 +1014,7 @@ get_nth_callarg (tree t, int n)
represented by _CST nodes. */
static tree
cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t,
cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun,
bool lval,
bool *non_constant_p, bool *overflow_p)
{
@ -1022,18 +1022,30 @@ cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t,
tree *args = (tree *) alloca (nargs * sizeof (tree));
tree new_call;
int i;
for (i = 0; i < nargs; ++i)
/* Don't fold __builtin_constant_p within a constexpr function. */
if (DECL_FUNCTION_CODE (fun) == BUILT_IN_CONSTANT_P
&& current_function_decl
&& DECL_DECLARED_CONSTEXPR_P (current_function_decl))
{
args[i] = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, i),
lval,
non_constant_p, overflow_p);
if (ctx->quiet && *non_constant_p)
return t;
*non_constant_p = true;
return t;
}
if (*non_constant_p)
return t;
/* Be permissive for arguments to built-ins; __builtin_constant_p should
return constant false for a non-constant argument. */
constexpr_ctx new_ctx = *ctx;
new_ctx.quiet = true;
bool dummy1 = false, dummy2 = false;
for (i = 0; i < nargs; ++i)
args[i] = cxx_eval_constant_expression (&new_ctx, CALL_EXPR_ARG (t, i),
lval, &dummy1, &dummy2);
bool save_ffbcp = force_folding_builtin_constant_p;
force_folding_builtin_constant_p = true;
new_call = fold_build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t),
CALL_EXPR_FN (t), nargs, args);
force_folding_builtin_constant_p = save_ffbcp;
VERIFY_CONSTANT (new_call);
return new_call;
}
@ -1200,7 +1212,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
return void_node;
if (is_builtin_fn (fun))
return cxx_eval_builtin_function_call (ctx, t,
return cxx_eval_builtin_function_call (ctx, t, fun,
lval, non_constant_p, overflow_p);
if (!DECL_DECLARED_CONSTEXPR_P (fun))
{

6
gcc/testsuite/g++.dg/cpp0x/constexpr-builtin3.C Normal file
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@ -0,0 +1,6 @@
// PR c++/65656
// { dg-options "-std=c++11 -O" }
int main(int argc, char *argv[]) {
constexpr bool x = __builtin_constant_p(argc);
}