Array length reduction should throw in strict mode if it can't delete an element.

src/ic/mips/handler-compiler-mips.cc

Index: src/ic/mips/handler-compiler-mips.cc
diff --git a/src/ic/mips/handler-compiler-mips.cc b/src/ic/mips/handler-compiler-mips.cc
index 9ee05775064e2a6d1ab6bb5fad6e90177a94add2..f6b13be5377d2883913ac9d6bb8e6e9d676cd968 100644
--- a/src/ic/mips/handler-compiler-mips.cc
+++ b/src/ic/mips/handler-compiler-mips.cc
@@ -585,41 +585,50 @@ void NamedLoadHandlerCompiler::GenerateLoadConstant(Handle<Object> value) {
 
 void NamedLoadHandlerCompiler::GenerateLoadCallback(
     Register reg, Handle<AccessorInfo> callback) {
-  // Build AccessorInfo::args_ list on the stack and push property name below
-  // the exit frame to make GC aware of them and store pointers to them.
-  STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 0);
-  STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 1);
-  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 2);
-  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 3);
-  STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 4);
-  STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 5);
-  STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 6);
-  DCHECK(!scratch2().is(reg));
-  DCHECK(!scratch3().is(reg));
-  DCHECK(!scratch4().is(reg));
-  __ push(receiver());
+  DCHECK(!AreAliased(scratch2(), scratch3(), scratch4(), receiver()));
+  DCHECK(!AreAliased(scratch2(), scratch3(), scratch4(), reg));
+
+  // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
+  // name below the exit frame to make GC aware of them.
+  STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
+  STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
+  STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
+  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
+  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
+  STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
+  STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
+  STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);
+
+  // Here and below +1 is for name() pushed after the args_ array.
+  typedef PropertyCallbackArguments PCA;
+  __ Subu(sp, sp, (PCA::kArgsLength + 1) * kPointerSize);
+  __ sw(receiver(), MemOperand(sp, (PCA::kThisIndex + 1) * kPointerSize));
   Handle<Object> data(callback->data(), isolate());
   if (data->IsUndefined() || data->IsSmi()) {
-    __ li(scratch3(), data);
+    __ li(scratch2(), data);
   } else {
     Handle<WeakCell> cell =
         isolate()->factory()->NewWeakCell(Handle<HeapObject>::cast(data));
     // The callback is alive if this instruction is executed,
     // so the weak cell is not cleared and points to data.
-    __ GetWeakValue(scratch3(), cell);
+    __ GetWeakValue(scratch2(), cell);
   }
-  __ Subu(sp, sp, 6 * kPointerSize);
-  __ sw(scratch3(), MemOperand(sp, 5 * kPointerSize));
-  __ LoadRoot(scratch3(), Heap::kUndefinedValueRootIndex);
-  __ sw(scratch3(), MemOperand(sp, 4 * kPointerSize));
-  __ sw(scratch3(), MemOperand(sp, 3 * kPointerSize));
-  __ li(scratch4(), Operand(ExternalReference::isolate_address(isolate())));
-  __ sw(scratch4(), MemOperand(sp, 2 * kPointerSize));
-  __ sw(reg, MemOperand(sp, 1 * kPointerSize));
+  __ sw(scratch2(), MemOperand(sp, (PCA::kDataIndex + 1) * kPointerSize));
+  __ LoadRoot(scratch2(), Heap::kUndefinedValueRootIndex);
+  __ sw(scratch2(),
+        MemOperand(sp, (PCA::kReturnValueOffset + 1) * kPointerSize));
+  __ sw(scratch2(), MemOperand(sp, (PCA::kReturnValueDefaultValueIndex + 1) *
+                                       kPointerSize));
+  __ li(scratch2(), Operand(ExternalReference::isolate_address(isolate())));
+  __ sw(scratch2(), MemOperand(sp, (PCA::kIsolateIndex + 1) * kPointerSize));
+  __ sw(reg, MemOperand(sp, (PCA::kHolderIndex + 1) * kPointerSize));
+  // should_throw_on_error -> false
+  DCHECK(Smi::FromInt(0) == nullptr);
+  __ sw(zero_reg,
+        MemOperand(sp, (PCA::kShouldThrowOnErrorIndex + 1) * kPointerSize));
+
   __ sw(name(), MemOperand(sp, 0 * kPointerSize));
-  __ Addu(scratch2(), sp, 1 * kPointerSize);
 
-  __ mov(a2, scratch2());  // Saved in case scratch2 == a1.
   // Abi for CallApiGetter.
   Register getter_address_reg = ApiGetterDescriptor::function_address();
 
@@ -705,7 +714,8 @@ void NamedLoadHandlerCompiler::GenerateLoadInterceptor(Register holder_reg) {
 
 
 Handle<Code> NamedStoreHandlerCompiler::CompileStoreCallback(
-    Handle<JSObject> object, Handle<Name> name, Handle<AccessorInfo> callback) {
+    Handle<JSObject> object, Handle<Name> name, Handle<AccessorInfo> callback,
+    LanguageMode language_mode) {
   Register holder_reg = Frontend(name);
 
   __ Push(receiver(), holder_reg);  // Receiver.
@@ -720,6 +730,7 @@ Handle<Code> NamedStoreHandlerCompiler::CompileStoreCallback(
   __ push(at);
   __ li(at, Operand(name));
   __ Push(at, value());
+  __ Push(Smi::FromInt(language_mode));
 
   // Do tail-call to the runtime system.
   __ TailCallRuntime(Runtime::kStoreCallbackProperty);