[libcxx-commits] [libcxx] 7c49052 - [libc++] Use init_priority(100) when possible

[Louis Dionne via libcxx-commits]

Author: Louis Dionne
Date: 2021-10-06T15:53:56-04:00
New Revision: 7c49052b170f76f19be64a5572d31ad8f5df4e61

URL: https://github.com/llvm/llvm-project/commit/7c49052b170f76f19be64a5572d31ad8f5df4e61
DIFF: https://github.com/llvm/llvm-project/commit/7c49052b170f76f19be64a5572d31ad8f5df4e61.diff

LOG: [libc++] Use init_priority(100) when possible

Priorities below 101 are reserved for the implementation, so that's what
we should be using here. That is unfortunately only supported on more
recent versions of Clang. See https://reviews.llvm.org/D31413 for details.

Differential Revision: https://reviews.llvm.org/D95972

Added: 
    

Modified: 
    libcxx/include/__config
    libcxx/src/experimental/memory_resource.cpp
    libcxx/src/iostream.cpp

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__config b/libcxx/include/__config
index 856b7b384593..31f98faaa721 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1330,7 +1330,13 @@ extern "C" _LIBCPP_FUNC_VIS void __sanitizer_annotate_contiguous_container(
 #endif
 
 #if __has_attribute(init_priority)
-# define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(101)))
+    // TODO: Remove this once we drop support for building libc++ with old Clangs
+#   if (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER < 1200) || \
+       (defined(__apple_build_version__) && __apple_build_version__ < 13000000)
+#     define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(101)))
+#   else
+#     define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(100)))
+#   endif
 #else
 # define _LIBCPP_INIT_PRIORITY_MAX
 #endif

diff  --git a/libcxx/src/experimental/memory_resource.cpp b/libcxx/src/experimental/memory_resource.cpp
index ffe8021514fc..5f9d3b8a4cbe 100644
--- a/libcxx/src/experimental/memory_resource.cpp
+++ b/libcxx/src/experimental/memory_resource.cpp
@@ -76,7 +76,9 @@ union ResourceInitHelper {
   ~ResourceInitHelper() {}
 };
 
+# 79 "memory_resource.cpp" 1 3
 _LIBCPP_SAFE_STATIC ResourceInitHelper res_init _LIBCPP_INIT_PRIORITY_MAX;
+# 81 "memory_resource.cpp" 2
 
 } // end namespace
 

diff  --git a/libcxx/src/iostream.cpp b/libcxx/src/iostream.cpp
index 16e05cf0698c..99bd5288842a 100644
--- a/libcxx/src/iostream.cpp
+++ b/libcxx/src/iostream.cpp
@@ -73,7 +73,12 @@ __asm__("?wclog@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream at _WU?$char_t
 #endif
 ;
 
+// Hacky way to make the compiler believe that we're inside a system header so
+// it doesn't flag the use of the init_priority attribute with a value that's
+// reserved for the implementation (we're the implementation).
+# 80 "iostream.cpp" 1 3
 _LIBCPP_HIDDEN ios_base::Init __start_std_streams _LIBCPP_INIT_PRIORITY_MAX;
+# 82 "iostream.cpp" 2
 
 // On Windows the TLS storage for locales needs to be initialized before we create
 // the standard streams, otherwise it may not be alive during program termination