2 files changed, 66 insertions, 14 deletions

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 5017c2cdf5..9f2880fb4e 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -698,6 +698,15 @@ void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
       // Count this failure so that we know that template argument deduction
       // has failed.
       ++NumSFINAEErrors;
+
+      // Make a copy of this suppressed diagnostic and store it with the
+      // template-deduction information.
+      if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
+        Diagnostic DiagInfo(&Diags);
+        (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
+                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
+      }
+
       Diags.setLastDiagnosticIgnored();
       Diags.Clear();
       return;
@@ -714,6 +723,15 @@ void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
 
       // Suppress this diagnostic.
       ++NumSFINAEErrors;
+
+      // Make a copy of this suppressed diagnostic and store it with the
+      // template-deduction information.
+      if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
+        Diagnostic DiagInfo(&Diags);
+        (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
+                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
+      }
+
       Diags.setLastDiagnosticIgnored();
       Diags.Clear();
 
@@ -730,13 +748,13 @@ void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
     case DiagnosticIDs::SFINAE_Suppress:
       // Make a copy of this suppressed diagnostic and store it with the
       // template-deduction information;
-      Diagnostic DiagInfo(&Diags);
-        
-      if (*Info)
+      if (*Info) {
+        Diagnostic DiagInfo(&Diags);
         (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(),
-                        PartialDiagnostic(DiagInfo,Context.getDiagAllocator()));
-        
-      // Suppress this diagnostic.        
+                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
+      }
+
+      // Suppress this diagnostic.
       Diags.setLastDiagnosticIgnored();
       Diags.Clear();
       return;
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 007ea0fdcd..f065d38d92 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -28,6 +28,7 @@
 #include "clang/Basic/PartialDiagnostic.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/STLExtras.h"
 #include <algorithm>
 
@@ -541,6 +542,7 @@ static MakeDeductionFailureInfo(ASTContext &Context,
                                 TemplateDeductionInfo &Info) {
   OverloadCandidate::DeductionFailureInfo Result;
   Result.Result = static_cast<unsigned>(TDK);
+  Result.HasDiagnostic = false;
   Result.Data = 0;
   switch (TDK) {
   case Sema::TDK_Success:
@@ -567,6 +569,12 @@ static MakeDeductionFailureInfo(ASTContext &Context,
 
   case Sema::TDK_SubstitutionFailure:
     Result.Data = Info.take();
+    if (Info.hasSFINAEDiagnostic()) {
+      PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
+          SourceLocation(), PartialDiagnostic::NullDiagnostic());
+      Info.takeSFINAEDiagnostic(*Diag);
+      Result.HasDiagnostic = true;
+    }
     break;
 
   case Sema::TDK_NonDeducedMismatch:
@@ -594,8 +602,12 @@ void OverloadCandidate::DeductionFailureInfo::Destroy() {
     break;
 
   case Sema::TDK_SubstitutionFailure:
-    // FIXME: Destroy the template arugment list?
+    // FIXME: Destroy the template argument list?
     Data = 0;
+    if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
+      Diag->~PartialDiagnosticAt();
+      HasDiagnostic = false;
+    }
     break;
 
   // Unhandled
@@ -605,6 +617,13 @@ void OverloadCandidate::DeductionFailureInfo::Destroy() {
   }
 }
 
+PartialDiagnosticAt *
+OverloadCandidate::DeductionFailureInfo::getSFINAEDiagnostic() {
+  if (HasDiagnostic)
+    return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
+  return 0;
+}
+
 TemplateParameter
 OverloadCandidate::DeductionFailureInfo::getTemplateParameter() {
   switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
@@ -8235,14 +8254,29 @@ void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
     return;
 
   case Sema::TDK_SubstitutionFailure: {
-    std::string ArgString;
-    if (TemplateArgumentList *Args
-                            = Cand->DeductionFailure.getTemplateArgumentList())
-      ArgString = S.getTemplateArgumentBindingsText(
-                    Fn->getDescribedFunctionTemplate()->getTemplateParameters(),
-                                                    *Args);
+    // Format the template argument list into the argument string.
+    llvm::SmallString<128> TemplateArgString;
+    if (TemplateArgumentList *Args =
+          Cand->DeductionFailure.getTemplateArgumentList()) {
+      TemplateArgString = " ";
+      TemplateArgString += S.getTemplateArgumentBindingsText(
+          Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args);
+    }
+
+    // Format the SFINAE diagnostic into the argument string.
+    // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
+    //        formatted message in another diagnostic.
+    llvm::SmallString<128> SFINAEArgString;
+    SourceRange R;
+    if (PartialDiagnosticAt *PDiag =
+          Cand->DeductionFailure.getSFINAEDiagnostic()) {
+      SFINAEArgString = ": ";
+      R = SourceRange(PDiag->first, PDiag->first);
+      PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
+    }
+
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure)
-      << ArgString;
+      << TemplateArgString << SFINAEArgString << R;
     MaybeEmitInheritedConstructorNote(S, Fn);
     return;
   }