On 10/29/20 10:35 PM, Marek Polacek wrote:
Jon suggested turning this warning off when we're not actually
evaluating the operand. This patch does that.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
OK.
gcc/cp/ChangeLog:
PR c++/97632
* init.c (build_new_1): Disable -Winit-list-lifetime for an unevaluated
operand.
gcc/testsuite/ChangeLog:
PR c++/97632
* g++.dg/warn/Winit-list4.C: New test.
---
gcc/cp/init.c | 2 +-
gcc/testsuite/g++.dg/warn/Winit-list4.C | 15 +++++++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/warn/Winit-list4.C
diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index 1bddb6555dc..ffb84ea5b09 100644
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -2957,7 +2957,7 @@ build_new_1 (vec<tree, va_gc> **placement, tree type,
tree nelts,
return error_mark_node;
}
- if (is_std_init_list (elt_type))
+ if (is_std_init_list (elt_type) && !cp_unevaluated_operand)
warning (OPT_Winit_list_lifetime,
"%<new%> of %<initializer_list%> does not "
"extend the lifetime of the underlying array");
diff --git a/gcc/testsuite/g++.dg/warn/Winit-list4.C
b/gcc/testsuite/g++.dg/warn/Winit-list4.C
new file mode 100644
index 00000000000..d136187e2c6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Winit-list4.C
@@ -0,0 +1,15 @@
+// PR c++/97632
+// { dg-do compile { target c++20 } }
+// Test we don't warn in an unevaluated operand.
+
+#include <initializer_list>
+
+template<typename _Tp>
+concept default_initializable
+ = requires
+ {
+ _Tp{};
+ (void) ::new _Tp; // { dg-bogus "does not extend the lifetime" }
+ };
+
+static_assert(default_initializable<std::initializer_list<int>>);
base-commit: dec1eb4c276f1b3c003154c159b539eb7110a13f
