[libc++] Use more appropriate conditional for ABI macro definition

The inline function definition ABI macro is gated on COFF dllexport
semantics, so it's more appropriate to mark it with the object file
format macro rather than the generic _WIN32 macro. We now have no uses
of _WIN32 apart from those used to define the other Windows macros :)

Clarify the ABI macro comment and make the object file format check
exhaustive while I'm here.

llvm-svn: 300097

diff --git a/libcxx/include/__config b/libcxx/include/__config
index aab774d..b9d47ac 100644 (file)
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -35,6 +35,16 @@
 #define _LIBCPP_ABI_VERSION 1
 #endif
 
+#if defined(__ELF__)
+#define _LIBCPP_OBJECT_FORMAT_ELF   1
+#elif defined(__MACH__)
+#define _LIBCPP_OBJECT_FORMAT_MACHO 1
+#elif defined(_WIN32)
+#define _LIBCPP_OBJECT_FORMAT_COFF  1
+#else
+#error Unknown object file format
+#endif
+
 #if defined(_LIBCPP_ABI_UNSTABLE) || _LIBCPP_ABI_VERSION >= 2
 // Change short string representation so that string data starts at offset 0,
 // improving its alignment in some cases.
@@ -63,9 +73,12 @@
 // using that class define their own copies.
 #define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
 #elif _LIBCPP_ABI_VERSION == 1
-#if !defined(_WIN32)
+#if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
 // Enable compiling copies of now inline methods into the dylib to support
-// applications compiled against older libraries.
+// applications compiled against older libraries. This is unnecessary with
+// COFF dllexport semantics, since dllexport forces a non-inline definition
+// of inline functions to be emitted anyway. Our own non-inline copy would
+// conflict with the dllexport-emitted copy, so we disable it.
 #define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
 #endif
 // Feature macros for disabling pre ABI v1 features. All of these options
@@ -572,14 +585,6 @@ namespace std {
 
 #endif // _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM]
 
-#if defined(__ELF__)
-#define _LIBCPP_OBJECT_FORMAT_ELF   1
-#elif defined(__MACH__)
-#define _LIBCPP_OBJECT_FORMAT_MACHO 1
-#else
-#define _LIBCPP_OBJECT_FORMAT_COFF  1
-#endif
-
 #if defined(_LIBCPP_OBJECT_FORMAT_COFF)
 #if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
 # define _LIBCPP_DLL_VIS