[committed] libstdc++: Fix noexcept on dtors in <experimental/scope> [PR114152]

[Jonathan Wakely <jwakely@redhat.com>]

Tested x86_64-linux, pushed to trunk. Backport to gcc-13 to follow.

-- >8 --

The PR points out that the destructors all have incorrect
noexcept-specifiers.

libstdc++-v3/ChangeLog:

	PR libstdc++/114152
	* include/experimental/scope (scope_exit scope_fail): Make
	destructor unconditionally noexcept.
	(scope_sucess): Fix noexcept-specifier.
	* testsuite/experimental/scopeguard/114152.cc: New test.
---
 libstdc++-v3/include/experimental/scope       |  6 ++---
 .../experimental/scopeguard/114152.cc         | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 libstdc++-v3/testsuite/experimental/scopeguard/114152.cc

diff --git a/libstdc++-v3/include/experimental/scope b/libstdc++-v3/include/experimental/scope
index 5dbeac14795..ea273e8c095 100644
--- a/libstdc++-v3/include/experimental/scope
+++ b/libstdc++-v3/include/experimental/scope
@@ -97,7 +97,7 @@ namespace experimental::inline fundamentals_v3
       scope_exit& operator=(const scope_exit&) = delete;
       scope_exit& operator=(scope_exit&&) = delete;
 
-      ~scope_exit() noexcept(noexcept(this->_M_exit_function))
+      ~scope_exit() noexcept
       {
 	if (_M_execute_on_destruction)
 	  _M_exit_function();
@@ -157,7 +157,7 @@ namespace experimental::inline fundamentals_v3
       scope_fail& operator=(const scope_fail&) = delete;
       scope_fail& operator=(scope_fail&&) = delete;
 
-      ~scope_fail() noexcept(noexcept(this->_M_exit_function))
+      ~scope_fail() noexcept
       {
 	if (std::uncaught_exceptions() > _M_uncaught_init)
 	  _M_exit_function();
@@ -211,7 +211,7 @@ namespace experimental::inline fundamentals_v3
       scope_success& operator=(const scope_success&) = delete;
       scope_success& operator=(scope_success&&) = delete;
 
-      ~scope_success() noexcept(noexcept(this->_M_exit_function))
+      ~scope_success() noexcept(noexcept(this->_M_exit_function()))
       {
 	if (std::uncaught_exceptions() <= _M_uncaught_init)
 	  _M_exit_function();
diff --git a/libstdc++-v3/testsuite/experimental/scopeguard/114152.cc b/libstdc++-v3/testsuite/experimental/scopeguard/114152.cc
new file mode 100644
index 00000000000..63c1f710e9f
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/scopeguard/114152.cc
@@ -0,0 +1,24 @@
+// { dg-do compile { target c++20 } }
+
+// PR libstdc++/114152
+// Wrong exception specifiers for LFTSv3 scope guard destructors
+
+#include <experimental/scope>
+
+using namespace std::experimental;
+
+struct F {
+  void operator()() noexcept(false);
+};
+
+static_assert( noexcept(std::declval<scope_exit<F>&>().~scope_exit()) );
+static_assert( noexcept(std::declval<scope_fail<F>&>().~scope_fail()) );
+static_assert( ! noexcept(std::declval<scope_success<F>&>().~scope_success()) );
+
+struct G {
+  void operator()() noexcept(true);
+};
+
+static_assert( noexcept(std::declval<scope_exit<G>&>().~scope_exit()) );
+static_assert( noexcept(std::declval<scope_fail<G>&>().~scope_fail()) );
+static_assert( noexcept(std::declval<scope_success<G>&>().~scope_success()) );
-- 
2.43.0