Resolve references to "this" the same way as normal variables

src/mips/full-codegen-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
 
 // Note on Mips implementation:
 //
@@ skipping 117 matching lines @@
   if (strlen(FLAG_stop_at) > 0 &&
       info->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
     __ stop("stop-at");
   }
 #endif
 
   // Sloppy mode functions and builtins need to replace the receiver with the
   // global proxy when called as functions (without an explicit receiver
   // object).
   if (is_sloppy(info->language_mode()) && !info->is_native() &&
-      info->MayUseThis()) {
+      info->MayUseThis() && info->scope()->has_this_declaration()) {
     Label ok;
     int receiver_offset = info->scope()->num_parameters() * kPointerSize;
     __ lw(at, MemOperand(sp, receiver_offset));
     __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
     __ Branch(&ok, ne, a2, Operand(at));
 
     __ lw(a2, GlobalObjectOperand());
     __ lw(a2, FieldMemOperand(a2, GlobalObject::kGlobalProxyOffset));
 
     __ sw(a2, MemOperand(sp, receiver_offset));
@@ skipping 69 matching lines @@
       __ push(a1);
       __ CallRuntime(Runtime::kNewFunctionContext, 1);
     }
     function_in_register = false;
     // Context is returned in v0. It replaces the context passed to us.
     // It's saved in the stack and kept live in cp.
     __ mov(cp, v0);
     __ sw(v0, MemOperand(fp, StandardFrameConstants::kContextOffset));
     // Copy any necessary parameters into the context.
     int num_parameters = info->scope()->num_parameters();
-    for (int i = 0; i < num_parameters; i++) {
-      Variable* var = scope()->parameter(i);
+    int first_parameter = info->scope()->has_this_declaration() ? -1 : 0;
+    for (int i = first_parameter; i < num_parameters; i++) {
+      Variable* var = (i == -1) ? scope()->receiver() : scope()->parameter(i);
       if (var->IsContextSlot()) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
                                  (num_parameters - 1 - i) * kPointerSize;
         // Load parameter from stack.
         __ lw(a0, MemOperand(fp, parameter_offset));
         // Store it in the context.
         MemOperand target = ContextOperand(cp, var->index());
         __ sw(a0, target);
 
         // Update the write barrier.
@@ skipping 2790 matching lines @@
   if (arg_count > 0) {
     __ lw(t3, MemOperand(sp, arg_count * kPointerSize));
   } else {
     __ LoadRoot(t3, Heap::kUndefinedValueRootIndex);
   }
 
   // t2: the receiver of the enclosing function.
   __ lw(t2, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
 
   // t1: the receiver of the enclosing function.
-  int receiver_offset = 2 + info_->scope()->num_parameters();
-  __ lw(t1, MemOperand(fp, receiver_offset * kPointerSize));
+  Variable* this_var = scope()->LookupThis();
+  DCHECK_NOT_NULL(this_var);
+  __ lw(t1, VarOperand(this_var, t1));
 
   // t0: the language mode.
   __ li(t0, Operand(Smi::FromInt(language_mode())));
 
   // a1: the start position of the scope the calls resides in.
   __ li(a1, Operand(Smi::FromInt(scope()->start_position())));
 
   // Do the runtime call.
   __ Push(t3);
   __ Push(t2, t1, t0, a1);
@@ skipping 2395 matching lines @@
       Assembler::target_address_at(pc_immediate_load_address)) ==
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS