When redefining a macro don't warn twice if it's not used and don't warn for duplicate

definition by command line options. Fixes rdar://8875916.

llvm-svn: 123767

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index f422d254f0f..0f0d25b887a 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1527,7 +1527,7 @@ void Preprocessor::HandleDefineDirective(Token &DefineTok) {
     // then don't bother calling MacroInfo::isIdenticalTo.
     if (!getDiagnostics().getSuppressSystemWarnings() ||
         !SourceMgr.isInSystemHeader(DefineTok.getLocation())) {
-      if (!OtherMI->isUsed())
+      if (!OtherMI->isUsed() && OtherMI->isWarnIfUnused())
         Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used);
 
       // Macros must be identical.  This means all tokens and whitespace
@@ -1539,6 +1539,8 @@ void Preprocessor::HandleDefineDirective(Token &DefineTok) {
         Diag(OtherMI->getDefinitionLoc(), diag::note_previous_definition);
       }
     }
+    if (OtherMI->isWarnIfUnused())
+      WarnUnusedMacroLocs.erase(OtherMI->getDefinitionLoc());
     ReleaseMacroInfo(OtherMI);
   }