4 files changed, 39 insertions, 27 deletions

diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 97952a04f23..8c393c525eb 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -221,8 +221,6 @@ Diagnostic::Diagnostic(DiagnosticClient *client) : Client(client) {
   
   ArgToStringFn = DummyArgToStringFn;
   ArgToStringCookie = 0;
-
-  InPostDiagnosticHook = false;
 }
 
 Diagnostic::~Diagnostic() {
@@ -411,15 +409,7 @@ void Diagnostic::ProcessDiag() {
   Client->HandleDiagnostic(DiagLevel, Info);
   if (Client->IncludeInDiagnosticCounts()) ++NumDiagnostics;
 
-  // Invoke any post-diagnostic hooks.
-  unsigned LastDiag = CurDiagID;
   CurDiagID = ~0U;
-  
-  InPostDiagnosticHook = true;
-  for (unsigned Hook = 0; Hook < NumPostDiagnosticHooks; ++Hook)
-    PostDiagnosticHooks[Hook].Hook(LastDiag, 
-                                   PostDiagnosticHooks[Hook].Cookie);
-  InPostDiagnosticHook = false;
 }
 
 
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 992d3ecbee2..9662c43bb3e 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -295,3 +295,19 @@ NamedDecl *Sema::getCurFunctionOrMethodDecl() {
   return 0;
 }
 
+Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
+  this->Emit();
+  
+  // If this is not a note, and we're in a template instantiation
+  // that is different from the last template instantiation where
+  // we emitted an error, print a template instantiation
+  // backtrace.
+  if (!SemaRef.Diags.isBuiltinNote(DiagID) &&
+      !SemaRef.ActiveTemplateInstantiations.empty() &&
+      SemaRef.ActiveTemplateInstantiations.back() 
+        != SemaRef.LastTemplateInstantiationErrorContext) {
+    SemaRef.PrintInstantiationStack();
+    SemaRef.LastTemplateInstantiationErrorContext 
+      = SemaRef.ActiveTemplateInstantiations.back();
+  }
+}
diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 2e019c9b7f9..76c3b05aab5 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -241,15 +241,30 @@ public:
   Diagnostic &getDiagnostics() const { return Diags; }
   SourceManager &getSourceManager() const { return SourceMgr; }
 
-  /// The primitive diagnostic helpers.
-  DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) {
+  /// \brief Helper class that creates diagnostics with optional
+  /// template instantiation stacks.
+  ///
+  /// This class provides a wrapper around the basic DiagnosticBuilder
+  /// class that emits diagnostics. SemaDiagnosticBuilder is
+  /// responsible for emitting the diagnostic (as DiagnosticBuilder
+  /// does) and, if the diagnostic comes from inside a template
+  /// instantiation, printing the template instantiation stack as
+  /// well.
+  class SemaDiagnosticBuilder : public DiagnosticBuilder {
+    Sema &SemaRef;
+    unsigned DiagID;
+
+  public:
+    SemaDiagnosticBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
+      : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) { }
+
+    ~SemaDiagnosticBuilder();
+  };
+
+  /// \brief Emit a diagnostic.
+  SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) {
     DiagnosticBuilder DB = Diags.Report(FullSourceLoc(Loc, SourceMgr), DiagID);
-    if (!Diags.isBuiltinNote(DiagID) && 
-        !ActiveTemplateInstantiations.empty() &&
-        ActiveTemplateInstantiations.back() 
-          != LastTemplateInstantiationErrorContext)
-      DB << PostDiagnosticHook(PrintInstantiationStackHook, this);
-    return DB;
+    return SemaDiagnosticBuilder(DB, *this, DiagID);
   }
 
   virtual void DeleteExpr(ExprTy *E);
@@ -1858,7 +1873,6 @@ public:
     operator=(const InstantiatingTemplate&); // not implemented
   };
 
-  static void PrintInstantiationStackHook(unsigned DiagID, void *Cookie);
   void PrintInstantiationStack();
 
   QualType InstantiateType(QualType T, const TemplateArgument *TemplateArgs,
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 10f9926b3e7..e856e91ffcc 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -93,14 +93,6 @@ bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
   return true;
 }
 
-/// \brief Post-diagnostic hook for printing the instantiation stack.
-void Sema::PrintInstantiationStackHook(unsigned, void *Cookie) {
-  Sema &SemaRef = *static_cast<Sema*>(Cookie);
-  SemaRef.PrintInstantiationStack();
-  SemaRef.LastTemplateInstantiationErrorContext 
-    = SemaRef.ActiveTemplateInstantiations.back();
-}
-
 /// \brief Prints the current instantiation stack through a series of
 /// notes.
 void Sema::PrintInstantiationStack() {