MIPS: Implement correct checking for inherited readonliness on assignment.

src/mips/stub-cache-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 404 matching lines @@
 }
 
 
 // Generate StoreField code, value is passed in a0 register.
 // After executing generated code, the receiver_reg and name_reg
 // may be clobbered.
 void StubCompiler::GenerateStoreField(MacroAssembler* masm,
                                       Handle<JSObject> object,
                                       int index,
                                       Handle<Map> transition,
+                                      Handle<String> name,
                                       Register receiver_reg,
                                       Register name_reg,
-                                      Register scratch,
+                                      Register scratch1,
+                                      Register scratch2,
                                       Label* miss_label) {
   // a0 : value.
   Label exit;
+
+  LookupResult lookup(masm->isolate());
+  object->Lookup(*name, &lookup);
+  if (lookup.IsFound() && (lookup.IsReadOnly() || !lookup.IsCacheable())) {
+    // In sloppy mode, we could just return the value and be done. However, we
+    // might be in strict mode, where we have to throw. Since we cannot tell,
+    // go into slow case unconditionally.
+    __ jmp(miss_label);
+    return;
+  }
+
   // Check that the map of the object hasn't changed.
   CompareMapMode mode = transition.is_null() ? ALLOW_ELEMENT_TRANSITION_MAPS
                                              : REQUIRE_EXACT_MAP;
-  __ CheckMap(receiver_reg, scratch, Handle<Map>(object->map()), miss_label,
+  __ CheckMap(receiver_reg, scratch1, Handle<Map>(object->map()), miss_label,
               DO_SMI_CHECK, mode);
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {
-    __ CheckAccessGlobalProxy(receiver_reg, scratch, miss_label);
+    __ CheckAccessGlobalProxy(receiver_reg, scratch1, miss_label);
+  }
+
+  // Check that we are allowed to write this.
+  if (!transition.is_null() && object->GetPrototype()->IsJSObject()) {
+    JSObject* holder;
+    if (lookup.IsFound()) {
+      holder = lookup.holder();
+    } else {
+      // Find the top object.
+      holder = *object;
+      do {
+        holder = JSObject::cast(holder->GetPrototype());
+      } while (holder->GetPrototype()->IsJSObject());
+    }
+    // We need an extra register, push
+    __ push(name_reg);
+    Label miss_pop, done_check;
+    CheckPrototypes(object, receiver_reg, Handle<JSObject>(holder), name_reg,
+                    scratch1, scratch2, name, &miss_pop);
+    __ jmp(&done_check);
+    __ bind(&miss_pop);
+    __ pop(name_reg);
+    __ jmp(miss_label);
+    __ bind(&done_check);
+    __ pop(name_reg);
   }
 
   // Stub never generated for non-global objects that require access
   // checks.
   ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
 
   // Perform map transition for the receiver if necessary.
   if (!transition.is_null() && (object->map()->unused_property_fields() == 0)) {
     // The properties must be extended before we can store the value.
     // We jump to a runtime call that extends the properties array.
     __ push(receiver_reg);
     __ li(a2, Operand(transition));
     __ Push(a2, a0);
     __ TailCallExternalReference(
            ExternalReference(IC_Utility(IC::kSharedStoreIC_ExtendStorage),
                              masm->isolate()),
            3, 1);
     return;
   }
 
   if (!transition.is_null()) {
     // Update the map of the object.
-    __ li(scratch, Operand(transition));
-    __ sw(scratch, FieldMemOperand(receiver_reg, HeapObject::kMapOffset));
+    __ li(scratch1, Operand(transition));
+    __ sw(scratch1, FieldMemOperand(receiver_reg, HeapObject::kMapOffset));
 
     // Update the write barrier for the map field and pass the now unused
     // name_reg as scratch register.
     __ RecordWriteField(receiver_reg,
                         HeapObject::kMapOffset,
-                        scratch,
+                        scratch1,
                         name_reg,
                         kRAHasNotBeenSaved,
                         kDontSaveFPRegs,
                         OMIT_REMEMBERED_SET,
                         OMIT_SMI_CHECK);
   }
 
   // Adjust for the number of properties stored in the object. Even in the
   // face of a transition we can use the old map here because the size of the
   // object and the number of in-object properties is not going to change.
   index -= object->map()->inobject_properties();
 
   if (index < 0) {
     // Set the property straight into the object.
     int offset = object->map()->instance_size() + (index * kPointerSize);
     __ sw(a0, FieldMemOperand(receiver_reg, offset));
 
     // Skip updating write barrier if storing a smi.
-    __ JumpIfSmi(a0, &exit, scratch);
+    __ JumpIfSmi(a0, &exit, scratch1);
 
     // Update the write barrier for the array address.
     // Pass the now unused name_reg as a scratch register.
     __ mov(name_reg, a0);
     __ RecordWriteField(receiver_reg,
                         offset,
                         name_reg,
-                        scratch,
+                        scratch1,
                         kRAHasNotBeenSaved,
                         kDontSaveFPRegs);
   } else {
     // Write to the properties array.
     int offset = index * kPointerSize + FixedArray::kHeaderSize;
     // Get the properties array.
-    __ lw(scratch, FieldMemOperand(receiver_reg, JSObject::kPropertiesOffset));
-    __ sw(a0, FieldMemOperand(scratch, offset));
+    __ lw(scratch1,
+          FieldMemOperand(receiver_reg, JSObject::kPropertiesOffset));
+    __ sw(a0, FieldMemOperand(scratch1, offset));
 
     // Skip updating write barrier if storing a smi.
     __ JumpIfSmi(a0, &exit);
 
     // Update the write barrier for the array address.
     // Ok to clobber receiver_reg and name_reg, since we return.
     __ mov(name_reg, a0);
-    __ RecordWriteField(scratch,
+    __ RecordWriteField(scratch1,
                         offset,
                         name_reg,
                         receiver_reg,
                         kRAHasNotBeenSaved,
                         kDontSaveFPRegs);
   }
 
   // Return the value (register v0).
   __ bind(&exit);
   __ mov(v0, a0);
@@ skipping 2040 matching lines @@
                                                   Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- a0    : value
   //  -- a1    : receiver
   //  -- a2    : name
   //  -- ra    : return address
   // -----------------------------------
   Label miss;
 
   // Name register might be clobbered.
-  GenerateStoreField(masm(), object, index, transition, a1, a2, a3, &miss);
+  GenerateStoreField(masm(),
+                     object,
+                     index,
+                     transition,
+                     name,
+                     a1, a2, a3, t0,
+                     &miss);
   __ bind(&miss);
   __ li(a2, Operand(Handle<String>(name)));  // Restore name.
   Handle<Code> ic = masm()->isolate()->builtins()->Builtins::StoreIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode(transition.is_null() ? FIELD : MAP_TRANSITION, name);
 }
 
 
@@ skipping 518 matching lines @@
   Label miss;
 
   Counters* counters = masm()->isolate()->counters();
   __ IncrementCounter(counters->keyed_store_field(), 1, a3, t0);
 
   // Check that the name has not changed.
   __ Branch(&miss, ne, a1, Operand(name));
 
   // a3 is used as scratch register. a1 and a2 keep their values if a jump to
   // the miss label is generated.
-  GenerateStoreField(masm(), object, index, transition, a2, a1, a3, &miss);
+  GenerateStoreField(masm(),
+                     object,
+                     index,
+                     transition,
+                     name,
+                     a2, a1, a3, t0,
+                     &miss);
   __ bind(&miss);
 
   __ DecrementCounter(counters->keyed_store_field(), 1, a3, t0);
   Handle<Code> ic = masm()->isolate()->builtins()->KeyedStoreIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode(transition.is_null() ? FIELD : MAP_TRANSITION, name);
 }
 
@@ skipping 1478 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS