ObjectiveC. Define a new cc1 flag

-fobjc-subscripting-legacy-runtime which is off 
by default and on only when using ObjectiveC
legacy runtime. Use this flag to allow
array and dictionary subscripting and disallow
objectiveC pointer arithmatic in ObjectiveC
legacy runtime. // rdar://15363492

llvm-svn: 193889

clang/include/clang/Basic/LangOptions.def

@@ -143,6 +143,7 @@ LANGOPT(NoBitFieldTypeAlign , 1, 0, "bit-field type alignment")
 LANGOPT(HexagonQdsp6Compat , 1, 0, "hexagon-qdsp6 backward compatibility")
 LANGOPT(ObjCAutoRefCount , 1, 0, "Objective-C automated reference counting")
 LANGOPT(ObjCARCWeak         , 1, 0, "__weak support in the ARC runtime")
+LANGOPT(ObjCSubscriptingLegacyRuntime         , 1, 0, "Subscripting support in legacy ObjectiveC runtime")
 LANGOPT(FakeAddressSpaceMap , 1, 0, "OpenCL fake address space map")
 ENUM_LANGOPT(AddressSpaceMapMangling , AddrSpaceMapMangling, 2, ASMM_Target, "OpenCL address space map mangling mode")
 

clang/include/clang/Basic/LangOptions.h

@@ -97,6 +97,11 @@ public:
   bool isSignedOverflowDefined() const {
     return getSignedOverflowBehavior() == SOB_Defined;
   }
+  
+  bool isSubscriptPointerArithmetic() const {
+    return ObjCRuntime.isSubscriptPointerArithmetic() &&
+           !ObjCSubscriptingLegacyRuntime;
+  }
 
   /// \brief Reset all of the options that are not considered when building a
   /// module.

clang/include/clang/Driver/CC1Options.td

@@ -472,6 +472,8 @@ def fno_deprecated_macro : Flag<["-"], "fno-deprecated-macro">,
   HelpText<"Undefines the __DEPRECATED macro">;
 def fsized_deallocation : Flag<["-"], "fsized-deallocation">,
   HelpText<"Enable C++1y sized global deallocation functions">;
+def fobjc_subscripting_legacy_runtime : Flag<["-"], "fobjc-subscripting-legacy-runtime">,
+  HelpText<"Allow Objective-C array and dictionary subscripting in legacy runtime">;
 
 //===----------------------------------------------------------------------===//
 // Header Search Options

clang/lib/Frontend/CompilerInvocation.cpp

@@ -1218,6 +1218,10 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
 
     if (Args.hasArg(OPT_fno_objc_infer_related_result_type))
       Opts.ObjCInferRelatedResultType = 0;
+    
+    if (Args.hasArg(OPT_fobjc_subscripting_legacy_runtime))
+      Opts.ObjCSubscriptingLegacyRuntime =
+        (Opts.ObjCRuntime.getKind() == ObjCRuntime::FragileMacOSX);
   }
     
   if (Args.hasArg(OPT_fgnu89_inline))

clang/lib/Sema/SemaExpr.cpp

@@ -3639,7 +3639,8 @@ static bool checkArithmeticOnObjCPointer(Sema &S,
                                          SourceLocation opLoc,
                                          Expr *op) {
   assert(op->getType()->isObjCObjectPointerType());
-  if (S.LangOpts.ObjCRuntime.allowsPointerArithmetic())
+  if (S.LangOpts.ObjCRuntime.allowsPointerArithmetic() &&
+      !S.LangOpts.ObjCSubscriptingLegacyRuntime)
     return false;
 
   S.Diag(opLoc, diag::err_arithmetic_nonfragile_interface)
@@ -3744,15 +3745,10 @@ Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc,
 
     // Use custom logic if this should be the pseudo-object subscript
     // expression.
-    if (!LangOpts.ObjCRuntime.isSubscriptPointerArithmetic())
+    if (!LangOpts.isSubscriptPointerArithmetic())
       return BuildObjCSubscriptExpression(RLoc, BaseExpr, IndexExpr, 0, 0);
 
     ResultType = PTy->getPointeeType();
-    if (!LangOpts.ObjCRuntime.allowsPointerArithmetic()) {
-      Diag(LLoc, diag::err_subscript_nonfragile_interface)
-        << ResultType << BaseExpr->getSourceRange();
-      return ExprError();
-    }
   } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) {
      // Handle the uncommon case of "123[Ptr]".
     BaseExpr = RHSExp;
@@ -3764,7 +3760,7 @@ Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc,
     BaseExpr = RHSExp;
     IndexExpr = LHSExp;
     ResultType = PTy->getPointeeType();
-    if (!LangOpts.ObjCRuntime.allowsPointerArithmetic()) {
+    if (!LangOpts.isSubscriptPointerArithmetic()) {
       Diag(LLoc, diag::err_subscript_nonfragile_interface)
         << ResultType << BaseExpr->getSourceRange();
       return ExprError();

clang/lib/Sema/SemaExprObjC.cpp

@@ -602,7 +602,7 @@ ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
                                         Expr *IndexExpr,
                                         ObjCMethodDecl *getterMethod,
                                         ObjCMethodDecl *setterMethod) {
-  assert(!LangOpts.ObjCRuntime.isSubscriptPointerArithmetic());
+  assert(!LangOpts.isSubscriptPointerArithmetic());
 
   // We can't get dependent types here; our callers should have
   // filtered them out.

clang/test/SemaObjC/objc-array-literal.m

@@ -1,5 +1,7 @@
 // RUN: %clang_cc1  -fsyntax-only -verify %s
 // rdar://10111397
+// RUN: %clang_cc1  -fsyntax-only -triple i386-apple-macosx10.9.0 -fobjc-runtime=macosx-fragile-10.9.0 -fobjc-subscripting-legacy-runtime -verify %s
+// rdar://15363492
 
 #if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
 typedef unsigned long NSUInteger;

clang/test/SemaObjC/objc-dictionary-literal.m

@@ -1,5 +1,7 @@
 // RUN: %clang_cc1  -fsyntax-only -verify %s
 // rdar://11062080
+// RUN: %clang_cc1  -fsyntax-only -triple i386-apple-macosx10.9.0 -fobjc-runtime=macosx-fragile-10.9.0 -fobjc-subscripting-legacy-runtime -verify %s
+// rdar://15363492
 
 @interface NSNumber
 + (NSNumber *)numberWithChar:(char)value;