4 files changed, 62 insertions, 31 deletions

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index df746928c8..397bd14d8a 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -6911,12 +6911,10 @@ public:
   /// given type.
   ExprResult forceUnknownAnyToType(Expr *E, QualType ToType);
 
-  /// \brief Handle an expression that's being passed to an
+  /// \brief Type-check an expression that's being passed to an
   /// __unknown_anytype parameter.
-  ///
-  /// \return the effective parameter type to use, or null if the
-  ///   argument is invalid.
-  QualType checkUnknownAnyArg(Expr *&result);
+  ExprResult checkUnknownAnyArg(SourceLocation callLoc,
+                                Expr *result, QualType &paramType);
 
   // CheckVectorCast - check type constraints for vectors.
   // Since vectors are an extension, there are no C standard reference for this.
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 7dd17a028f..e1b9950eca 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -3835,11 +3835,8 @@ bool Sema::GatherArgumentsForCall(SourceLocation CallLoc,
     if (Proto->getResultType() == Context.UnknownAnyTy &&
         FDecl && FDecl->isExternC()) {
       for (unsigned i = ArgIx; i != NumArgs; ++i) {
-        ExprResult arg;
-        if (isa<ExplicitCastExpr>(Args[i]->IgnoreParens()))
-          arg = DefaultFunctionArrayLvalueConversion(Args[i]);
-        else
-          arg = DefaultVariadicArgumentPromotion(Args[i], CallType, FDecl);
+        QualType paramType; // ignored
+        ExprResult arg = checkUnknownAnyArg(CallLoc, Args[i], paramType);
         Invalid |= arg.isInvalid();
         AllArgs.push_back(arg.take());
       }
@@ -12013,20 +12010,27 @@ ExprResult Sema::forceUnknownAnyToType(Expr *E, QualType ToType) {
   return RebuildUnknownAnyExpr(*this, ToType).Visit(E);
 }
 
-QualType Sema::checkUnknownAnyArg(Expr *&arg) {
-  // Filter out placeholders.
-  ExprResult argR = CheckPlaceholderExpr(arg);
-  if (argR.isInvalid()) return QualType();
-  arg = argR.take();
-
-  // If the argument is an explicit cast, use that exact type as the
-  // effective parameter type.
-  if (ExplicitCastExpr *castArg = dyn_cast<ExplicitCastExpr>(arg)) {
-    return castArg->getTypeAsWritten();
+ExprResult Sema::checkUnknownAnyArg(SourceLocation callLoc,
+                                    Expr *arg, QualType &paramType) {
+  // If the syntactic form of the argument is not an explicit cast of
+  // any sort, just do default argument promotion.
+  ExplicitCastExpr *castArg = dyn_cast<ExplicitCastExpr>(arg->IgnoreParens());
+  if (!castArg) {
+    ExprResult result = DefaultArgumentPromotion(arg);
+    if (result.isInvalid()) return ExprError();
+    paramType = result.get()->getType();
+    return result;
   }
 
-  // Otherwise, try to pass by value.
-  return arg->getType().getUnqualifiedType();
+  // Otherwise, use the type that was written in the explicit cast.
+  assert(!arg->hasPlaceholderType());
+  paramType = castArg->getTypeAsWritten();
+
+  // Copy-initialize a parameter of that type.
+  InitializedEntity entity =
+    InitializedEntity::InitializeParameter(Context, paramType,
+                                           /*consumed*/ false);
+  return PerformCopyInitialization(entity, callLoc, Owned(arg));
 }
 
 static ExprResult diagnoseUnknownAnyExpr(Sema &S, Expr *E) {
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 74a3292054..75f8c48022 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -1135,10 +1135,16 @@ bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
       if (Args[i]->isTypeDependent())
         continue;
 
-      ExprResult Result = DefaultArgumentPromotion(Args[i]);
-      if (Result.isInvalid())
+      ExprResult result;
+      if (getLangOpts().DebuggerSupport) {
+        QualType paramTy; // ignored
+        result = checkUnknownAnyArg(lbrac, Args[i], paramTy);
+      } else {
+        result = DefaultArgumentPromotion(Args[i]);
+      }
+      if (result.isInvalid())
         return true;
-      Args[i] = Result.take();
+      Args[i] = result.take();
     }
 
     unsigned DiagID;
@@ -1199,14 +1205,17 @@ bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
     // If the parameter is __unknown_anytype, infer its type
     // from the argument.
     if (param->getType() == Context.UnknownAnyTy) {
-      QualType paramType = checkUnknownAnyArg(argExpr);
-      if (paramType.isNull()) {
+      QualType paramType;
+      ExprResult argE = checkUnknownAnyArg(lbrac, argExpr, paramType);
+      if (argE.isInvalid()) {
         IsError = true;
-        continue;
-      }
+      } else {
+        Args[i] = argE.take();
 
-      // Update the parameter type in-place.
-      param->setType(paramType);
+        // Update the parameter type in-place.
+        param->setType(paramType);
+      }
+      continue;
     }
 
     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
diff --git a/test/CodeGenObjCXX/unknown-anytype.mm b/test/CodeGenObjCXX/unknown-anytype.mm
new file mode 100644
index 0000000000..692f70a752
--- /dev/null
+++ b/test/CodeGenObjCXX/unknown-anytype.mm
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fdebugger-support -funknown-anytype -emit-llvm -o - %s | FileCheck %s
+
+// rdar://12565338
+
+@interface A @end
+void test0(A *a) {
+  (void) [a test0: (float) 2.0];
+}
+// CHECK: define void @_Z5test0P1A(
+// CHECK: call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, float)*)(
+
+@interface B
+- (void) test1: (__unknown_anytype) x;
+@end
+void test1(B *b) {
+  (void) [b test1: (float) 2.0];
+}
+// CHECK: define void @_Z5test1P1B(
+// CHECK: call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, float)*)(
+