[gcc r13-8067] libstdc++: Fix std::hash<std::stacktrace> [PR112348]

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:16635b89f36c07b9e06c48a93d1bfafa93178328

commit r13-8067-g16635b89f36c07b9e06c48a93d1bfafa93178328
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Nov 14 22:36:31 2023 +0000

    libstdc++: Fix std::hash<std::stacktrace> [PR112348]
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/112348
            * include/std/stacktrace (hash<basic_stacktrace<Alloc>>): Fix
            type of hash function for entries.
            * testsuite/19_diagnostics/stacktrace/hash.cc: New test.
    
    (cherry picked from commit 6f2fc42d9e52e8322e718e0154cd235d00906f99)

Diff:
---
 libstdc++-v3/include/std/stacktrace                |  2 +-
 .../testsuite/19_diagnostics/stacktrace/hash.cc    | 23 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/stacktrace b/libstdc++-v3/include/std/stacktrace
index 346c7b14142..96702935433 100644
--- a/libstdc++-v3/include/std/stacktrace
+++ b/libstdc++-v3/include/std/stacktrace
@@ -790,7 +790,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       size_t
       operator()(const basic_stacktrace<_Allocator>& __st) const noexcept
       {
-	hash<stacktrace_entry::native_handle_type> __h;
+	hash<stacktrace_entry> __h;
 	size_t __val = _Hash_impl::hash(__st.size());
 	for (const auto& __f : __st)
 	  __val = _Hash_impl::__hash_combine(__h(__f), __val);
diff --git a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/hash.cc b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/hash.cc
new file mode 100644
index 00000000000..cf18476f2a7
--- /dev/null
+++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/hash.cc
@@ -0,0 +1,23 @@
+// { dg-options "-std=gnu++23 -lstdc++_libbacktrace" }
+// { dg-do run { target c++23 } }
+// { dg-require-effective-target stacktrace }
+
+#include <stacktrace>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+
+void
+test_hash()
+{
+  using Alloc = __gnu_test::uneq_allocator<std::stacktrace_entry>;
+  using S = std::basic_stacktrace<Alloc>;
+  S s;
+  std::size_t h = std::hash<S>()(s);
+  std::size_t h2 = std::hash<S>()(S::current());
+  VERIFY( h != h2 );
+}
+
+int main()
+{
+  test_hash();
+}