https://gcc.gnu.org/g:e2a178a5110db3b4c25773d386b047b27679bfe5
commit r14-11534-ge2a178a5110db3b4c25773d386b047b27679bfe5
Author: Jason Merrill <ja...@redhat.com>
Date: Fri Apr 4 17:34:08 2025 -0400
c++: __FUNCTION__ in lambda return type [PR118629]
In this testcase, the use of __FUNCTION__ is within a function parameter
scope, the lambda's. And P1787 changed __func__ to live in the parameter
scope. But [basic.scope.pdecl] says that the point of declaration of
__func__ is immediately before {, so in the trailing return type it isn't in
scope yet, so this __FUNCTION__ should refer to foo().
Looking first for a block scope, then a function parameter scope, gives us
the right result.
PR c++/118629
gcc/cp/ChangeLog:
* name-lookup.cc (pushdecl_outermost_localscope): Look for an
sk_block.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/lambda/lambda-__func__3.C: New test.
(cherry picked from commit 7d561820525fd3b9d8f3876333c0584d75e7c053)
Diff:
---
gcc/cp/name-lookup.cc | 8 +++++---
gcc/testsuite/g++.dg/cpp0x/lambda/lambda-__func__3.C | 6 ++++++
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 2e203e5ca0c8..53528cafa8f4 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -5125,9 +5125,11 @@ pushdecl_outermost_localscope (tree x)
cp_binding_level *b = NULL;
auto_cond_timevar tv (TV_NAME_LOOKUP);
- /* Find the scope just inside the function parms. */
- for (cp_binding_level *n = current_binding_level;
- n->kind != sk_function_parms; n = b->level_chain)
+ /* Find the block scope just inside the function parms. */
+ cp_binding_level *n = current_binding_level;
+ while (n && n->kind != sk_block)
+ n = n->level_chain;
+ for (; n && n->kind != sk_function_parms; n = b->level_chain)
b = n;
return b ? do_pushdecl_with_scope (x, b) : error_mark_node;
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-__func__3.C
b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-__func__3.C
new file mode 100644
index 000000000000..50ad6e55c1b1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-__func__3.C
@@ -0,0 +1,6 @@
+// PR c++/118629
+// { dg-do compile { target c++11 } }
+
+void foo() {
+ []() -> decltype(+__FUNCTION__) { return nullptr; };
+}
