Tested x86_64-pc-linux-gnu, applying to trunk and 14.
-- 8< --
Value-initialization built an AGGR_INIT_EXPR to set AGGR_INIT_ZERO_FIRST on.
Passing that AGGR_INIT_EXPR to maybe_constant_value returned a TARGET_EXPR,
which potential_constant_expression_1 mistook for a temporary.
We shouldn't add a TARGET_EXPR to the AGGR_INIT_EXPR in this case, just like
we already avoid adding it to CONSTRUCTOR or CALL_EXPR.
PR c++/119652
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_outermost_constant_expr): Also don't add a
TARGET_EXPR around AGGR_INIT_EXPR.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/constinit20.C: New test.
---
gcc/cp/constexpr.cc | 3 ++-
gcc/testsuite/g++.dg/cpp2a/constinit20.C | 18 ++++++++++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/constinit20.C
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index 37ea65cb655..497f64f3cea 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -9316,7 +9316,8 @@ cxx_eval_outermost_constant_expr (tree t, bool
allow_non_constant,
if (TREE_CODE (t) == TARGET_EXPR
&& TARGET_EXPR_INITIAL (t) == r)
return t;
- else if (TREE_CODE (t) == CONSTRUCTOR || TREE_CODE (t) == CALL_EXPR)
+ else if (TREE_CODE (t) == CONSTRUCTOR || TREE_CODE (t) == CALL_EXPR
+ || TREE_CODE (t) == AGGR_INIT_EXPR)
/* Don't add a TARGET_EXPR if our argument didn't have one. */;
else if (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_CLEANUP (t))
r = get_target_expr (r);
diff --git a/gcc/testsuite/g++.dg/cpp2a/constinit20.C
b/gcc/testsuite/g++.dg/cpp2a/constinit20.C
new file mode 100644
index 00000000000..9b043917dc3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/constinit20.C
@@ -0,0 +1,18 @@
+// PR c++/119652
+// { dg-do compile { target c++20 } }
+
+struct __shared_count {
+ constexpr __shared_count() {}
+ ~__shared_count();
+ int _M_pi = 0;
+};
+struct shared_ptr {
+ __shared_count _M_refcount;
+};
+struct A {
+ A() = default;
+ shared_ptr m;
+};
+constinit A a;
+constinit A b {};
+constinit A c = {};
base-commit: 3a77a567b1028a28ecbb2f2eadc351d8bd004352
--
2.49.0
