[libcxx] r314949 - [libc++] Allow users to explicitly specify ABI

[Shoaib Meenai via cfe-commits]

Author: smeenai
Date: Wed Oct  4 16:44:38 2017
New Revision: 314949

URL: http://llvm.org/viewvc/llvm-project?rev=314949&view=rev
Log:
[libc++] Allow users to explicitly specify ABI

libc++'s current heuristic for detecting Itanium vs. Microsoft ABI falls
short in some cases. For example, it will detect windows-itanium targets
as using the Microsoft ABI, since they set `_MSC_VER` (for compatibility
with Microsoft headers). Leave the current heuristic in place by default
but also allow users to explicitly specify the ABI if need be.

Modified:
    libcxx/trunk/CMakeLists.txt
    libcxx/trunk/include/__config
    libcxx/trunk/include/__config_site.in

Modified: libcxx/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/CMakeLists.txt?rev=314949&r1=314948&r2=314949&view=diff
==============================================================================
--- libcxx/trunk/CMakeLists.txt (original)
+++ libcxx/trunk/CMakeLists.txt Wed Oct  4 16:44:38 2017
@@ -99,6 +99,8 @@ cmake_dependent_option(LIBCXX_INSTALL_EX
         "LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY;LIBCXX_INSTALL_LIBRARY" OFF)
 set(LIBCXX_ABI_VERSION 1 CACHE STRING "ABI version of libc++.")
 option(LIBCXX_ABI_UNSTABLE "Unstable ABI of libc++." OFF)
+option(LIBCXX_ABI_ITANIUM "Ignore auto-detection and force use of the Itanium ABI.")
+option(LIBCXX_ABI_MICROSOFT "Ignore auto-detection and force use of the Microsoft ABI.")
 option(LIBCXX_USE_COMPILER_RT "Use compiler-rt instead of libgcc" OFF)
 
 if (NOT LIBCXX_ENABLE_SHARED AND NOT LIBCXX_ENABLE_STATIC)
@@ -337,6 +339,10 @@ if (LIBCXX_HAS_MUSL_LIBC AND NOT LIBCXX_
                       "when building for Musl with LIBCXX_HAS_MUSL_LIBC.")
 endif()
 
+if (LIBCXX_ABI_ITANIUM AND LIBCXX_ABI_MICROSOFT)
+  message(FATAL_ERROR "Only one of LIBCXX_ABI_ITANIUM and LIBCXX_ABI_MICROSOFT can be specified.")
+endif ()
+
 #===============================================================================
 # Configure System
 #===============================================================================
@@ -594,6 +600,8 @@ if (NOT LIBCXX_ABI_VERSION EQUAL "1")
   config_define(${LIBCXX_ABI_VERSION} _LIBCPP_ABI_VERSION)
 endif()
 config_define_if(LIBCXX_ABI_UNSTABLE _LIBCPP_ABI_UNSTABLE)
+config_define_if(LIBCXX_ABI_ITANIUM _LIBCPP_ABI_ITANIUM)
+config_define_if(LIBCXX_ABI_MICROSOFT _LIBCPP_ABI_MICROSOFT)
 
 config_define_if_not(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
 config_define_if_not(LIBCXX_ENABLE_STDIN _LIBCPP_HAS_NO_STDIN)

Modified: libcxx/trunk/include/__config
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__config?rev=314949&r1=314948&r2=314949&view=diff
==============================================================================
--- libcxx/trunk/include/__config (original)
+++ libcxx/trunk/include/__config Wed Oct  4 16:44:38 2017
@@ -157,11 +157,15 @@
 
 // FIXME: ABI detection should be done via compiler builtin macros. This
 // is just a placeholder until Clang implements such macros. For now assume
-// that Windows compilers pretending to be MSVC++ target the microsoft ABI.
-#if defined(_WIN32) && defined(_MSC_VER)
-# define _LIBCPP_ABI_MICROSOFT
-#else
-# define _LIBCPP_ABI_ITANIUM
+// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
+// and allow the user to explicitly specify the ABI to handle cases where this
+// heuristic falls short.
+#if !defined(_LIBCPP_ABI_ITANIUM) && !defined(_LIBCPP_ABI_MICROSOFT)
+# if defined(_WIN32) && defined(_MSC_VER)
+#  define _LIBCPP_ABI_MICROSOFT
+# else
+#  define _LIBCPP_ABI_ITANIUM
+# endif
 #endif
 
 // Need to detect which libc we're using if we're on Linux.

Modified: libcxx/trunk/include/__config_site.in
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__config_site.in?rev=314949&r1=314948&r2=314949&view=diff
==============================================================================
--- libcxx/trunk/include/__config_site.in (original)
+++ libcxx/trunk/include/__config_site.in Wed Oct  4 16:44:38 2017
@@ -12,6 +12,8 @@
 
 #cmakedefine _LIBCPP_ABI_VERSION @_LIBCPP_ABI_VERSION@
 #cmakedefine _LIBCPP_ABI_UNSTABLE
+#cmakedefine _LIBCPP_ABI_ITANIUM
+#cmakedefine _LIBCPP_ABI_MICROSOFT
 #cmakedefine _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
 #cmakedefine _LIBCPP_HAS_NO_STDIN
 #cmakedefine _LIBCPP_HAS_NO_STDOUT