[PATCH] libstdc++: Fix -fno-exceptions support in testsuite_allocator.h

[Patrick Palka]

On Thu, 28 May 2026, Patrick Palka wrote:

> On Thu, 28 May 2026, Jonathan Wakely wrote:
> 
> > On Thu, 28 May 2026 at 15:05, Jonathan Wakely <jwakely@redhat.com> wrote:
> > >
> > > On Thu, 28 May 2026 at 14:41, Patrick Palka <ppalka@redhat.com> wrote:
> > > >
> > > > On Thu, 28 May 2026, Patrick Palka wrote:
> > > >
> > > > > OK for trunk?
> > > > >
> > > > > -- >8 --
> > > > >
> > > > > This fixes the error
> > > > >
> > > > > .../testsuite_allocator.h:402:13: error: exception handling disabled, use ‘-fexceptions’ to enable
> > > > >   402 |             catch(...)
> > > > >       |             ^~~~~
> > > > >
> > > > > seen when running some C++23 library tests with -fno-exceptions.
> > > >
> > > > Huh, I wonder why we complain about this unguarded catch but not about
> > > > the one inside uneq_allocator::allocate a few lines above...
> > >
> > > I was just wondering that ...
> > 
> > Maybe it only complains about the members that are instantiated?
> > 
> > Both functions need the same fix, I think.
> 
> Yeah, I think you're right.  I'm surprised we haven't run into this for
> for ::allocate which was added in 2006.

Changes in v2:

  - Also guard the try/catch in ::allocate.

-- >8 --

Subject: [PATCH v2] libstdc++: Fix -fno-exceptions support in testsuite_allocator.h

This fixes the error

.../testsuite_allocator.h:402:13: error: exception handling disabled, use ‘-fexceptions’ to enable
  402 |             catch(...)
      |             ^~~~~

seen when running some C++23 library tests with -fno-exceptions.

libstdc++-v3/ChangeLog:

	* testsuite/util/testsuite_allocator.h
	(uneq_allocator::allocate): Guard try/catch with __cpp_exceptions.
	(uneq_allocator::allocate_at_least): Likewise.
---
 libstdc++-v3/testsuite/util/testsuite_allocator.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libstdc++-v3/testsuite/util/testsuite_allocator.h b/libstdc++-v3/testsuite/util/testsuite_allocator.h
index 27372a97161d..5b2f02d8042f 100644
--- a/libstdc++-v3/testsuite/util/testsuite_allocator.h
+++ b/libstdc++-v3/testsuite/util/testsuite_allocator.h
@@ -369,16 +369,20 @@ namespace __gnu_test
 	if (std::__is_constant_evaluated())
 	  return p;
 
+#if __cpp_exceptions
 	try
+#endif
 	  {
 	    get_map().insert(map_type::value_type(reinterpret_cast<void*>(p),
 						  personality));
 	  }
+#if __cpp_exceptions
 	catch(...)
 	  {
 	    AllocTraits::deallocate(*this, p, n);
 	    __throw_exception_again;
 	  }
+#endif
 
 	return p;
       }
@@ -394,16 +398,20 @@ namespace __gnu_test
 	  { return r; }
 	else
 	  {
+#if __cpp_exceptions
 	    try
+#endif
 	      {
 		get_map().insert(map_type::value_type(
 		      reinterpret_cast<void*>(r.ptr), personality));
 	      }
+#if __cpp_exceptions
 	    catch(...)
 	      {
 		AllocTraits::deallocate(*this, r.ptr, r.count);
 		__throw_exception_again;
 	      }
+#endif
 	    return r;
 	  }
       }
-- 
2.54.0.rc1.54.g60f07c4f5c