Merge pull request #22780 from ziglang/llvm20

LLVM 20

1 files changed, 42 insertions, 43 deletions

diff --git a/lib/libcxx/include/stdlib.h b/lib/libcxx/include/stdlib.h
index a74344d491..39550f36bb 100644
--- a/lib/libcxx/include/stdlib.h
+++ b/lib/libcxx/include/stdlib.h
@@ -7,17 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if defined(__need_malloc_and_calloc)
-
-#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#    pragma GCC system_header
-#  endif
-
-#  include_next <stdlib.h>
-
-#elif !defined(_LIBCPP_STDLIB_H)
-#  define _LIBCPP_STDLIB_H
-
 /*
     stdlib.h synopsis
 
@@ -84,68 +73,78 @@ void *aligned_alloc(size_t alignment, size_t size);                       // C11
 
 */
 
+#if defined(__cplusplus) && __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
+#  include <__cxx03/stdlib.h>
+#else
 #  include <__config>
 
 #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #    pragma GCC system_header
 #  endif
 
+// The inclusion of the system's <stdlib.h> is intentionally done once outside of any include
+// guards because some code expects to be able to include the underlying system header multiple
+// times to get different definitions based on the macros that are set before inclusion.
 #  if __has_include_next(<stdlib.h>)
 #    include_next <stdlib.h>
 #  endif
 
-#  ifdef __cplusplus
+#  if !defined(_LIBCPP_STDLIB_H)
+#    define _LIBCPP_STDLIB_H
+
+#    ifdef __cplusplus
 extern "C++" {
 // abs
 
-#    ifdef abs
-#      undef abs
-#    endif
-#    ifdef labs
-#      undef labs
-#    endif
-#    ifdef llabs
-#      undef llabs
-#    endif
+#      ifdef abs
+#        undef abs
+#      endif
+#      ifdef labs
+#        undef labs
+#      endif
+#      ifdef llabs
+#        undef llabs
+#      endif
 
 // MSVCRT already has the correct prototype in <stdlib.h> if __cplusplus is defined
-#    if !defined(_LIBCPP_MSVCRT)
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI long abs(long __x) _NOEXCEPT { return __builtin_labs(__x); }
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI long long abs(long long __x) _NOEXCEPT { return __builtin_llabs(__x); }
-#    endif // !defined(_LIBCPP_MSVCRT)
+#      if !defined(_LIBCPP_MSVCRT)
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI long abs(long __x) _NOEXCEPT { return __builtin_labs(__x); }
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI long long abs(long long __x) _NOEXCEPT { return __builtin_llabs(__x); }
+#      endif // !defined(_LIBCPP_MSVCRT)
 
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI float abs(float __lcpp_x) _NOEXCEPT {
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI float abs(float __lcpp_x) _NOEXCEPT {
   return __builtin_fabsf(__lcpp_x); // Use builtins to prevent needing math.h
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI double abs(double __lcpp_x) _NOEXCEPT {
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI double abs(double __lcpp_x) _NOEXCEPT {
   return __builtin_fabs(__lcpp_x);
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI long double abs(long double __lcpp_x) _NOEXCEPT {
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI long double abs(long double __lcpp_x) _NOEXCEPT {
   return __builtin_fabsl(__lcpp_x);
 }
 
 // div
 
-#    ifdef div
-#      undef div
-#    endif
-#    ifdef ldiv
-#      undef ldiv
-#    endif
-#    ifdef lldiv
-#      undef lldiv
-#    endif
+#      ifdef div
+#        undef div
+#      endif
+#      ifdef ldiv
+#        undef ldiv
+#      endif
+#      ifdef lldiv
+#        undef lldiv
+#      endif
 
 // MSVCRT already has the correct prototype in <stdlib.h> if __cplusplus is defined
-#    if !defined(_LIBCPP_MSVCRT)
+#      if !defined(_LIBCPP_MSVCRT)
 inline _LIBCPP_HIDE_FROM_ABI ldiv_t div(long __x, long __y) _NOEXCEPT { return ::ldiv(__x, __y); }
-#      if !(defined(__FreeBSD__) && !defined(__LONG_LONG_SUPPORTED))
+#        if !(defined(__FreeBSD__) && !defined(__LONG_LONG_SUPPORTED))
 inline _LIBCPP_HIDE_FROM_ABI lldiv_t div(long long __x, long long __y) _NOEXCEPT { return ::lldiv(__x, __y); }
-#      endif
-#    endif // _LIBCPP_MSVCRT
+#        endif
+#      endif // _LIBCPP_MSVCRT
 } // extern "C++"
-#  endif   // __cplusplus
+#    endif   // __cplusplus
+#  endif     // _LIBCPP_STDLIB_H
 
-#endif // _LIBCPP_STDLIB_H
+#endif // defined(__cplusplus) && __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)