Handle locations coming from macro instantiations properly in SourceManager::isBeforeInTranslationUnit().

Fixes rdar://8790245 and http://llvm.org/PR8821.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122536 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 17 insertions, 0 deletions

diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 54bdfd3166..409851f108 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -1198,6 +1198,13 @@ bool SourceManager::isBeforeInTranslationUnit(SourceLocation LHS,
   if (LHS == RHS)
     return false;
 
+  // If both locations are macro instantiations, the order of their offsets
+  // reflect the order that the tokens, pointed to by these locations, were
+  // instantiated (during parsing each token that is instantiated by a macro,
+  // expands the SLocEntries).
+  if (LHS.isMacroID() && RHS.isMacroID())
+    return LHS.getOffset() < RHS.getOffset();
+
   std::pair<FileID, unsigned> LOffs = getDecomposedLoc(LHS);
   std::pair<FileID, unsigned> ROffs = getDecomposedLoc(RHS);
 
diff --git a/test/Preprocessor/pragma_diagnostic_sections.cpp b/test/Preprocessor/pragma_diagnostic_sections.cpp
index 00163938cc..3349bdcf08 100644
--- a/test/Preprocessor/pragma_diagnostic_sections.cpp
+++ b/test/Preprocessor/pragma_diagnostic_sections.cpp
@@ -68,3 +68,13 @@ struct S2 {
 };
 
 //------------------------------------------------------------------------------
+
+// rdar://8790245
+#define MYMACRO \
+    _Pragma("clang diagnostic push") \
+    _Pragma("clang diagnostic ignored \"-Wunknown-pragmas\"") \
+    _Pragma("clang diagnostic pop")
+MYMACRO
+#undef MYMACRO
+
+//------------------------------------------------------------------------------