Fix diagnostic pragmas.

Diagnostic pragmas are broken because we don't keep track of the diagnostic state changes and we only check the current/latest state.
Problems manifest if a diagnostic is emitted for a source line that has different diagnostic state than the current state; this can affect
a lot of places, like C++ inline methods, template instantiations, the lexer, etc.

Fix the issue by having the Diagnostic object keep track of the source location of the pragmas so that it is able to know what is the diagnostic state at any given source location.

Fixes rdar://8365684.

llvm-svn: 121873

1 files changed, 9 insertions, 4 deletions

diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index 58625520a99..e6a53a10436 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -646,7 +646,11 @@ void Preprocessor::HandlePragmaPopMacro(Token &PopMacroTok) {
   if (iter != PragmaPushMacroInfo.end()) {
     // Release the MacroInfo currently associated with IdentInfo.
     MacroInfo *CurrentMI = getMacroInfo(IdentInfo);
-    if (CurrentMI) ReleaseMacroInfo(CurrentMI);
+    if (CurrentMI) {
+      if (CurrentMI->isWarnIfUnused())
+        WarnUnusedMacroLocs.erase(CurrentMI->getDefinitionLoc());
+      ReleaseMacroInfo(CurrentMI);
+    }
 
     // Get the MacroInfo we want to reinstall.
     MacroInfo *MacroToReInstall = iter->second.back();
@@ -810,6 +814,7 @@ public:
   explicit PragmaDiagnosticHandler() : PragmaHandler("diagnostic") {}
   virtual void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                             Token &DiagToken) {
+    SourceLocation DiagLoc = DiagToken.getLocation();
     Token Tok;
     PP.LexUnexpandedToken(Tok);
     if (Tok.isNot(tok::identifier)) {
@@ -828,12 +833,12 @@ public:
     else if (II->isStr("fatal"))
       Map = diag::MAP_FATAL;
     else if (II->isStr("pop")) {
-      if (!PP.getDiagnostics().popMappings())
+      if (!PP.getDiagnostics().popMappings(DiagLoc))
         PP.Diag(Tok, diag::warn_pragma_diagnostic_cannot_pop);
 
       return;
     } else if (II->isStr("push")) {
-      PP.getDiagnostics().pushMappings();
+      PP.getDiagnostics().pushMappings(DiagLoc);
       return;
     } else {
       PP.Diag(Tok, diag::warn_pragma_diagnostic_invalid);
@@ -883,7 +888,7 @@ public:
     }
 
     if (PP.getDiagnostics().setDiagnosticGroupMapping(WarningName.c_str()+2,
-                                                      Map))
+                                                      Map, DiagLoc))
       PP.Diag(StrToks[0].getLocation(),
               diag::warn_pragma_diagnostic_unknown_warning) << WarningName;
   }