[Bug libstdc++/122172] [16 Regression] 1571 regressions due to std::make_unsigned<_Atomic_word> since r16-3810

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122172

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We could also just do this:

--- a/libstdc++-v3/config/cpu/cris/atomic_word.h
+++ b/libstdc++-v3/config/cpu/cris/atomic_word.h
@@ -27,5 +27,6 @@

 // This entity must not cross a page boundary.
 typedef int _Atomic_word __attribute__ ((__aligned__ (4)));
+typedef unsigned int _Atomic_word_unsigned __attribute__ ((__aligned__ (4)));

 #endif
--- a/libstdc++-v3/config/cpu/generic/atomic_word.h
+++ b/libstdc++-v3/config/cpu/generic/atomic_word.h
@@ -30,6 +30,7 @@
 #define _GLIBCXX_ATOMIC_WORD_H 1

 typedef int _Atomic_word;
+typedef unsigned int _Atomic_word_unsigned;


 // This is a memory order acquire fence.
--- a/libstdc++-v3/config/cpu/sparc/atomic_word.h
+++ b/libstdc++-v3/config/cpu/sparc/atomic_word.h
@@ -27,8 +27,10 @@

 #ifdef __arch64__
   typedef long _Atomic_word;
+  typedef unsigned long _Atomic_word_unsigned;
 #else
   typedef int _Atomic_word;
+  typedef unsigned int _Atomic_word_unsigned;
 #endif

 #if defined(__sparc_v9__)
--- a/libstdc++-v3/include/ext/atomicity.h
+++ b/libstdc++-v3/include/ext/atomicity.h
@@ -39,9 +39,6 @@
 #if __has_include(<sys/single_threaded.h>)
 # include <sys/single_threaded.h>
 #endif
-#if __cplusplus >= 201103L
-# include <type_traits> // make_unsigned_t
-#endif

 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 {
@@ -96,14 +93,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   {
     _Atomic_word __result = *__mem;
     // Do the addition with an unsigned type so that overflow is well defined.
-#if __cplusplus >= 201103L
-    std::make_unsigned<_Atomic_word>::type __u;
-#else
-    // For most targets make_unsigned_t<_Atomic_word> is unsigned int,
-    // but 64-bit sparc uses long for _Atomic_word.
-    // Sign-extending to unsigned long works for both cases.
-    unsigned long __u;
-#endif
+    _Atomic_word_unsigned __u;
     __u = __result;
     __u += __val;
     *__mem = __u;
@@ -114,11 +104,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   __attribute__((__always_inline__))
   __atomic_add_single(_Atomic_word* __mem, int __val)
   {
-#if __cplusplus >= 201103L
-    std::make_unsigned<_Atomic_word>::type __u;
-#else
-    unsigned long __u; // see above
-#endif
+    _Atomic_word_unsigned __u;
     __u = *__mem;
     __u += __val;
     *__mem = __u;


Any private ports with custom atomic_word.h files would need to update them,
but that would be fine, I think.