5 files changed, 19 insertions, 2 deletions
diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
index 47a98bb462e..5e9395cae0e 100644
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -279,6 +279,10 @@ private:
   /// \brief Sticky flag set to \c true when an error is emitted.
   bool ErrorOccurred;
 
+  /// \brief Sticky flag set to \c true when an "uncompilable error" occurs.
+  /// I.e. an error that was not upgraded from a warning by -Werror.
+  bool UncompilableErrorOccurred;
+
   /// \brief Sticky flag set to \c true when a fatal error is emitted.
   bool FatalErrorOccurred;
 
@@ -558,6 +562,12 @@ public:
                                   SourceLocation Loc = SourceLocation());
 
   bool hasErrorOccurred() const { return ErrorOccurred; }
+
+  /// \brief Errors that actually prevent compilation, not those that are
+  /// upgraded from a warning by -Werror.
+  bool hasUncompilableErrorOccurred() const {
+    return UncompilableErrorOccurred;
+  }
   bool hasFatalErrorOccurred() const { return FatalErrorOccurred; }
   
   /// \brief Determine whether any kind of unrecoverable error has occurred.
diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 8346e39a672..f5eec02138b 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -97,6 +97,7 @@ bool DiagnosticsEngine::popMappings(SourceLocation Loc) {
 
 void DiagnosticsEngine::Reset() {
   ErrorOccurred = false;
+  UncompilableErrorOccurred = false;
   FatalErrorOccurred = false;
   UnrecoverableErrorOccurred = false;
   
diff --git a/clang/lib/Basic/DiagnosticIDs.cpp b/clang/lib/Basic/DiagnosticIDs.cpp
index 722d22aa384..1237fd5db19 100644
--- a/clang/lib/Basic/DiagnosticIDs.cpp
+++ b/clang/lib/Basic/DiagnosticIDs.cpp
@@ -628,6 +628,10 @@ bool DiagnosticIDs::ProcessDiag(DiagnosticsEngine &Diag) const {
     if (isUnrecoverable(DiagID))
       Diag.UnrecoverableErrorOccurred = true;
 
+    // Warnings which have been upgraded to errors do not prevent compilation.
+    if (isDefaultMappingAsError(DiagID))
+      Diag.UncompilableErrorOccurred = true;
+
     Diag.ErrorOccurred = true;
     if (Diag.Client->IncludeInDiagnosticCounts()) {
       ++Diag.NumErrors;
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 20f0fd8eef8..0eca503cd52 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -1423,7 +1423,7 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
   if (cast<DeclContext>(D)->isDependentContext())
     return;
 
-  if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred()) {
+  if (Diags.hasUncompilableErrorOccurred() || Diags.hasFatalErrorOccurred()) {
     // Flush out any possibly unreachable diagnostics.
     flushDiagnostics(S, fscope);
     return;
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 9dd77795379..502a8557284 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8125,7 +8125,9 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
     if (PP.getDiagnostics().hasErrorOccurred() ||
         PP.getDiagnostics().getSuppressAllDiagnostics()) {
       DiscardCleanupsInEvaluationContext();
-    } else if (!isa<FunctionTemplateDecl>(dcl)) {
+    }
+    if (!PP.getDiagnostics().hasUncompilableErrorOccurred() &&
+        !isa<FunctionTemplateDecl>(dcl)) {
       // Since the body is valid, issue any analysis-based warnings that are
       // enabled.
       ActivePolicy = &WP;