Tested x86_64-pc-linux-gnu, applying to trunk.
-- 8< --
r11-7740 limited constexpr rejection of conversion from pointer to integer
to manifestly constant-evaluated contexts; it should instead check whether
we're in strict mode.
The comment for that commit noted that making this change regressed other
tests, which turned out to be because maybe_constant_init_1 was not being
properly strict for variables declared constexpr/constinit.
PR c++/99456
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): Check strict
instead of manifestly_const_eval.
(maybe_constant_init_1): Be strict for static constexpr vars.
---
gcc/cp/constexpr.cc | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index f56c5c42c82..be73e707aaf 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -8479,7 +8479,7 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx,
tree t,
if (TREE_CODE (t) == CONVERT_EXPR
&& ARITHMETIC_TYPE_P (type)
&& INDIRECT_TYPE_P (TREE_TYPE (op))
- && ctx->manifestly_const_eval == mce_true)
+ && ctx->strict)
{
if (!ctx->quiet)
error_at (loc,
@@ -9747,16 +9747,26 @@ maybe_constant_init_1 (tree t, tree decl, bool
allow_non_constant,
{
/* [basic.start.static] allows constant-initialization of variables with
static or thread storage duration even if it isn't required, but we
- shouldn't bend the rules the same way for automatic variables. */
+ shouldn't bend the rules the same way for automatic variables.
+
+ But still enforce the requirements of constexpr/constinit.
+ [dcl.constinit] "If a variable declared with the constinit specifier
+ has dynamic initialization, the program is ill-formed, even if the
+ implementation would perform that initialization as a static
+ initialization." */
bool is_static = (decl && DECL_P (decl)
&& (TREE_STATIC (decl) || DECL_EXTERNAL (decl)));
+ bool strict = (!is_static
+ || (decl && DECL_P (decl)
+ && (DECL_DECLARED_CONSTEXPR_P (decl)
+ || DECL_DECLARED_CONSTINIT_P (decl))));
if (is_static)
manifestly_const_eval = mce_true;
if (cp_unevaluated_operand && manifestly_const_eval != mce_true)
return fold_to_constant (t);
- t = cxx_eval_outermost_constant_expr (t, allow_non_constant, !is_static,
+ t = cxx_eval_outermost_constant_expr (t, allow_non_constant, strict,
manifestly_const_eval,
false, decl);
}
base-commit: 0907a810f586b07636cc5b83dba6025eb5240655
--
2.49.0
