1 files changed, 49 insertions, 3 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index fac3c26d0e..3333b4eea9 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -9169,6 +9169,54 @@ DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
                                 /*ExplicitTemplateArgs=*/0, Args, NumArgs);
 }
 
+namespace {
+// Callback to limit the allowed keywords and to only accept typo corrections
+// that are keywords or whose decls refer to functions (or template functions)
+// that accept the given number of arguments.
+class RecoveryCallCCC : public CorrectionCandidateCallback {
+ public:
+  RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs)
+      : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) {
+    WantTypeSpecifiers = SemaRef.getLangOptions().CPlusPlus;
+    WantRemainingKeywords = false;
+  }
+
+  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
+    if (!candidate.getCorrectionDecl())
+      return candidate.isKeyword();
+
+    for (TypoCorrection::const_decl_iterator DI = candidate.begin(),
+           DIEnd = candidate.end(); DI != DIEnd; ++DI) {
+      FunctionDecl *FD = 0;
+      NamedDecl *ND = (*DI)->getUnderlyingDecl();
+      if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
+        FD = FTD->getTemplatedDecl();
+      if (!HasExplicitTemplateArgs && !FD) {
+        if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
+          // If the Decl is neither a function nor a template function,
+          // determine if it is a pointer or reference to a function. If so,
+          // check against the number of arguments expected for the pointee.
+          QualType ValType = cast<ValueDecl>(ND)->getType();
+          if (ValType->isAnyPointerType() || ValType->isReferenceType())
+            ValType = ValType->getPointeeType();
+          if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
+            if (FPT->getNumArgs() == NumArgs)
+              return true;
+        }
+      }
+      if (FD && FD->getNumParams() >= NumArgs &&
+          FD->getMinRequiredArguments() <= NumArgs)
+        return true;
+    }
+    return false;
+  }
+
+ private:
+  unsigned NumArgs;
+  bool HasExplicitTemplateArgs;
+};
+}
+
 /// Attempts to recover from a call where no functions were found.
 ///
 /// Returns true if new candidates were found.
@@ -9192,9 +9240,7 @@ BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
 
   LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
                  Sema::LookupOrdinaryName);
-  CorrectionCandidateCallback Validator;
-  Validator.WantTypeSpecifiers = SemaRef.getLangOptions().CPlusPlus;
-  Validator.WantRemainingKeywords = false;
+  RecoveryCallCCC Validator(SemaRef, NumArgs, ExplicitTemplateArgs != 0);
   if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
                               ExplicitTemplateArgs, Args, NumArgs) &&
       (!EmptyLookup ||