Disallow subclassing Arrays.

src/ia32/code-stubs-ia32.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_IA32
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 2234 matching lines @@
   __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
                            FixedArray::kHeaderSize));
 
   // Verify that ecx contains an AllocationSite
   Factory* factory = masm->isolate()->factory();
   __ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
          factory->allocation_site_map());
   __ j(not_equal, &miss);
 
   __ mov(ebx, ecx);
+  __ mov(edx, edi);
   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 2358 matching lines @@
     UNREACHABLE();
   }
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax : argc (only if argument_count() == ANY)
   //  -- ebx : AllocationSite or undefined
   //  -- edi : constructor
+  //  -- edx : Original constructor
   //  -- esp[0] : return address
   //  -- esp[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.
     __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ test(ecx, Immediate(kSmiTagMask));
     __ Assert(not_zero, kUnexpectedInitialMapForArrayFunction);
     __ CmpObjectType(ecx, MAP_TYPE, ecx);
     __ Assert(equal, kUnexpectedInitialMapForArrayFunction);
 
     // We should either have undefined in ebx or a valid AllocationSite
     __ AssertUndefinedOrAllocationSite(ebx);
   }
 
+  Label subclassing;
+
+  __ cmp(edx, edi);
+  __ j(not_equal, &subclassing);
+
   Label no_info;
   // If the feedback vector is the undefined value call an array constructor
   // that doesn't use AllocationSites.
   __ cmp(ebx, isolate()->factory()->undefined_value());
   __ j(equal, &no_info);
 
+  __ cmp(edx, edi);
+  __ j(not_equal, &subclassing);
+
   // Only look at the lower 16 bits of the transition info.
   __ mov(edx, FieldOperand(ebx, AllocationSite::kTransitionInfoOffset));
   __ SmiUntag(edx);
   STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
   __ and_(edx, Immediate(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) {
   Label not_zero_case, not_one_case;
   Label normal_sequence;
 
   __ test(eax, eax);
   __ j(not_zero, &not_zero_case);
@@ skipping 461 matching lines @@
                            ApiParameterOperand(2), kStackSpace, nullptr,
                            Operand(ebp, 7 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32