On 8/27/25 2:05 PM, Jakub Jelinek wrote:
On Mon, Aug 25, 2025 at 04:00:37PM -0400, Jason Merrill wrote:
On 8/25/25 12:02 PM, Jakub Jelinek wrote:
On Mon, Aug 25, 2025 at 11:55:24AM -0400, Patrick Palka wrote:
The following patch fixes that by testing DECL_TEMPLATE_INFO, dunno
what else would be more appropriate for this function is a template,
maybe decl_dependent_p?
I was going to suggest just replacing the !processing_template_decl check
with !in_template_context to distinguish a true template context but that
wouldn't work here because we also push a dummy template parameter list
when parsing an expansion statement... so failing that, your current
approach makes sense to me.
Based on Jason's comment on the PARM_DECL tsubst_expr patch, another
possibility is !uses_template_params (fco), either always, or
in
if (!processing_template_decl
|| (in_expansion_stmt && !uses_template_parms (fco)))
form.
I think changing !processing_template_decl to !uses_template_parms (fco)
makes sense.
The following passed bootstrap/regtest on x86_64-linux and i686-linux, ok
for trunk?
OK.
2025-08-27 Jakub Jelinek <ja...@redhat.com>
PR c++/121583
* semantics.cc (apply_deduced_return_type): Adjust
fun->returns*_struct when !uses_template_parms (fco) instead of
when !processing_template_decl.
* g++.dg/cpp26/expansion-stmt23.C: New test.
* g++.dg/cpp26/expansion-stmt24.C: New test.
--- gcc/cp/semantics.cc.jj 2025-08-15 22:38:28.907872033 +0200
+++ gcc/cp/semantics.cc 2025-08-23 18:02:09.130079505 +0200
@@ -14213,7 +14213,7 @@ apply_deduced_return_type (tree fco, tre
result);
DECL_RESULT (fco) = result;
- if (!processing_template_decl)
+ if (!uses_template_parms (fco))
if (function *fun = DECL_STRUCT_FUNCTION (fco))
{
bool aggr = aggregate_value_p (result, fco);
--- gcc/testsuite/g++.dg/cpp26/expansion-stmt23.C.jj 2025-08-23
17:49:13.816155626 +0200
+++ gcc/testsuite/g++.dg/cpp26/expansion-stmt23.C 2025-08-23
18:08:32.125064559 +0200
@@ -0,0 +1,17 @@
+// PR c++/121583
+// { dg-do compile { target c++14 } }
+// { dg-options "" }
+
+auto
+foo ()
+{
+ template for (int i : { 0 }) // { dg-warning "'template for' only available
with" "" { target c++23_down } }
+ return i;
+}
+
+auto
+bar ()
+{
+ template for (auto i : { 0 }) // { dg-warning "'template for' only available
with" "" { target c++23_down } }
+ return i;
+}
--- gcc/testsuite/g++.dg/cpp26/expansion-stmt24.C.jj 2025-08-23
18:08:46.988868108 +0200
+++ gcc/testsuite/g++.dg/cpp26/expansion-stmt24.C 2025-08-23
18:12:46.856697841 +0200
@@ -0,0 +1,10 @@
+// PR c++/121583
+// { dg-do compile { target c++14 } }
+// { dg-options "" }
+
+auto
+foo ()
+{
+ template for (auto i : { 0, 1, 2LL }) // { dg-warning "'template for' only
available with" "" { target c++23_down } }
+ return i; // { dg-error "inconsistent
deduction for auto return type: 'int' and then 'long long int'" }
+}
Jakub