1 files changed, 20 insertions, 14 deletions
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 6a3c898d8c3..6810379c6ff 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -574,13 +574,22 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   Builder.defineMacro("__clang_version__",
                       "\"" CLANG_VERSION_STRING " "
                       + getClangFullRepositoryVersion() + "\"");
-  if (!LangOpts.MSVCCompat) {
-    // Currently claim to be compatible with GCC 4.2.1-5621, but only if we're
-    // not compiling for MSVC compatibility
-    Builder.defineMacro("__GNUC_MINOR__", "2");
-    Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
-    Builder.defineMacro("__GNUC__", "4");
+
+  if (LangOpts.GNUCVersion != 0) {
+    // Major, minor, patch, are given two decimal places each, so 4.2.1 becomes
+    // 40201.
+    unsigned GNUCMajor = LangOpts.GNUCVersion / 100 / 100;
+    unsigned GNUCMinor = LangOpts.GNUCVersion / 100 % 100;
+    unsigned GNUCPatch = LangOpts.GNUCVersion % 100;
+    Builder.defineMacro("__GNUC__", Twine(GNUCMajor));
+    Builder.defineMacro("__GNUC_MINOR__", Twine(GNUCMinor));
+    Builder.defineMacro("__GNUC_PATCHLEVEL__", Twine(GNUCPatch));
     Builder.defineMacro("__GXX_ABI_VERSION", "1002");
+
+    if (LangOpts.CPlusPlus) {
+      Builder.defineMacro("__GNUG__", Twine(GNUCMajor));
+      Builder.defineMacro("__GXX_WEAK__");
+    }
   }
 
   // Define macros for the C11 / C++11 memory orderings
@@ -619,7 +628,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (!LangOpts.GNUMode && !LangOpts.MSVCCompat)
     Builder.defineMacro("__STRICT_ANSI__");
 
-  if (!LangOpts.MSVCCompat && LangOpts.CPlusPlus11)
+  if (LangOpts.GNUCVersion && LangOpts.CPlusPlus11)
     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
 
   if (LangOpts.ObjC) {
@@ -699,7 +708,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
 
   if (!LangOpts.MSVCCompat && LangOpts.Exceptions)
     Builder.defineMacro("__EXCEPTIONS");
-  if (!LangOpts.MSVCCompat && LangOpts.RTTI)
+  if (LangOpts.GNUCVersion && LangOpts.RTTI)
     Builder.defineMacro("__GXX_RTTI");
 
   if (LangOpts.SjLjExceptions)
@@ -713,11 +722,8 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (LangOpts.Deprecated)
     Builder.defineMacro("__DEPRECATED");
 
-  if (!LangOpts.MSVCCompat && LangOpts.CPlusPlus) {
-    Builder.defineMacro("__GNUG__", "4");
-    Builder.defineMacro("__GXX_WEAK__");
+  if (!LangOpts.MSVCCompat && LangOpts.CPlusPlus)
     Builder.defineMacro("__private_extern__", "extern");
-  }
 
   if (LangOpts.MicrosoftExt) {
     if (LangOpts.WChar) {
@@ -927,7 +933,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   else
     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
 
-  if (!LangOpts.MSVCCompat) {
+  if (LangOpts.GNUCVersion) {
     if (LangOpts.GNUInline || LangOpts.CPlusPlus)
       Builder.defineMacro("__GNUC_GNU_INLINE__");
     else
@@ -964,7 +970,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
 #undef DEFINE_LOCK_FREE_MACRO
   };
   addLockFreeMacros("__CLANG_ATOMIC_");
-  if (!LangOpts.MSVCCompat)
+  if (LangOpts.GNUCVersion)
     addLockFreeMacros("__GCC_ATOMIC_");
 
   if (LangOpts.NoInlineDefine)