On 6/24/24 21:00, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
for trunk/14?
-- >8 --
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable,
which is desirable for a by-value capture, but not for a by-ref capture
(of a reference).
I'm not sure why we would want it for by-value, either; regardless of
the capture kind, decltype(x) is int&.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): For a by-reference
capture proxy, don't strip the reference type (if any) of
the captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 4 +++-
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 11 +++++++++++
2 files changed, 14 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 08f5f245e7d..b4f626924af 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12076,9 +12076,11 @@ finish_decltype_type (tree expr, bool
id_expression_or_member_access_p,
{
if (is_normal_capture_proxy (expr))
{
+ bool by_ref = TYPE_REF_P (TREE_TYPE (expr));
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
+ if (!by_ref)
+ type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..9a5e435f14f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,11 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+}
