[gcc r16-7106] libstdc++: Disable false positive middle end warnings in std::shared_ptr [PR122197]

[Jonathan Wakely]

https://gcc.gnu.org/g:74e0bb3faacfccfdf5633ab7ad3a15549d4a954d

commit r16-7106-g74e0bb3faacfccfdf5633ab7ad3a15549d4a954d
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Jan 23 14:25:03 2026 +0000

    libstdc++: Disable false positive middle end warnings in std::shared_ptr [PR122197]
    
    Speculative devirtualization in GCC 16 causes some false positive
    warnings for unreachable paths. Use diagnostic pragmas to suppress
    those warnings until the regression is fixed.
    
    libstdc++-v3/ChangeLog:
    
            PR tree-optimization/122197
            * include/bits/shared_ptr_base.h (~_Sp_counted_deleter): Use
            diagnostic pragam to disable -Wfree-nonheap-object false
            positive.
            (~_Sp_counted_ptr_inplace): Likewise for -Warray-bounds false
            positive.
    
    Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>

Diff:
---
 libstdc++-v3/include/bits/shared_ptr_base.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h
index 88e0f4d58c6c..b92e3a4c90e4 100644
--- a/libstdc++-v3/include/bits/shared_ptr_base.h
+++ b/libstdc++-v3/include/bits/shared_ptr_base.h
@@ -579,7 +579,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept
       : _M_impl(__p, std::move(__d), __a) { }
 
+#pragma GCC diagnostic push // PR tree-optimization/122197
+#pragma GCC diagnostic ignored "-Wfree-nonheap-object"
+  template<typename> class auto_ptr;
       ~_Sp_counted_deleter() noexcept { }
+#pragma GCC diagnostic pop
 
       virtual void
       _M_dispose() noexcept
@@ -667,7 +671,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	      std::forward<_Args>(__args)...); // might throw
 	}
 
+#pragma GCC diagnostic push // PR tree-optimization/122197
+#pragma GCC diagnostic ignored "-Warray-bounds"
       ~_Sp_counted_ptr_inplace() noexcept { }
+#pragma GCC diagnostic pop
 
       virtual void
       _M_dispose() noexcept