Disallow subclassing Arrays.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 2790 matching lines @@
   __ sll(at, a3, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(at, a2, Operand(at));
   __ lw(t0, FieldMemOperand(at, FixedArray::kHeaderSize));
 
   // Verify that t0 contains an AllocationSite
   __ lw(t1, FieldMemOperand(t0, HeapObject::kMapOffset));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&miss, ne, t1, Operand(at));
 
   __ mov(a2, t0);
+  __ mov(a3, a1);
   ArrayConstructorStub stub(masm->isolate(), arg_count());
   __ TailCallStub(&stub);
 
   __ bind(&miss);
   GenerateMiss(masm);
 
   // The slow case, we need this no matter what to complete a call after a miss.
   CallFunctionNoFeedback(masm,
                          arg_count(),
                          true,
@@ skipping 1971 matching lines @@
     UNREACHABLE();
   }
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0 : argc (only if argument_count() == ANY)
   //  -- a1 : constructor
   //  -- a2 : AllocationSite or undefined
+  //  -- a3 : Original constructor
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
 
   if (FLAG_debug_code) {
     // The array construct code is only set for the global and natives
     // builtin Array functions which always have maps.
 
     // Initial map for the builtin Array function should be a map.
     __ lw(t0, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ SmiTst(t0, at);
     __ Assert(ne, kUnexpectedInitialMapForArrayFunction,
         at, Operand(zero_reg));
     __ GetObjectType(t0, t0, t1);
     __ Assert(eq, kUnexpectedInitialMapForArrayFunction,
         t1, Operand(MAP_TYPE));
 
     // We should either have undefined in a2 or a valid AllocationSite
     __ AssertUndefinedOrAllocationSite(a2, t0);
   }
 
+  Label subclassing;
+  __ Branch(&subclassing, ne, a1, Operand(a3));
+
   Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   __ Branch(&no_info, eq, a2, Operand(at));
 
   __ lw(a3, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
   __ SmiUntag(a3);
   STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
   __ And(a3, a3, Operand(AllocationSite::ElementsKindBits::kMask));
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
+
+  __ bind(&subclassing);
+  __ TailCallRuntime(Runtime::kThrowArrayNotSubclassableError, 0, 1);
 }
 
 
 void InternalArrayConstructorStub::GenerateCase(
     MacroAssembler* masm, ElementsKind kind) {
 
   InternalArrayNoArgumentConstructorStub stub0(isolate(), kind);
   __ TailCallStub(&stub0, lo, a0, Operand(1));
 
   InternalArrayNArgumentsConstructorStub stubN(isolate(), kind);
@@ skipping 367 matching lines @@
                            kStackUnwindSpace, kInvalidStackOffset,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS