Crankshaft is now able to compile top level code even if there is a ScriptContext.

src/full-codegen/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.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 172 matching lines @@
       }
       int remaining = locals_count % kMaxPushes;
       // Emit the remaining pushes.
       __ Subu(sp, sp, Operand(remaining * kPointerSize));
       for (int i  = 0; i < remaining; i++) {
         __ sw(t5, MemOperand(sp, i * kPointerSize));
       }
     }
   }
 
-  bool function_in_register = true;
+  bool function_in_register_a1 = true;
 
   // Possibly allocate a local context.
   if (info->scope()->num_heap_slots() > 0) {
     Comment cmnt(masm_, "[ Allocate context");
     // Argument to NewContext is the function, which is still in a1.
     bool need_write_barrier = true;
     int slots = info->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
     if (info->scope()->is_script_scope()) {
       __ push(a1);
       __ Push(info->scope()->GetScopeInfo(info->isolate()));
       __ CallRuntime(Runtime::kNewScriptContext, 2);
     } else if (slots <= FastNewContextStub::kMaximumSlots) {
       FastNewContextStub stub(isolate(), slots);
       __ CallStub(&stub);
       // Result of FastNewContextStub is always in new space.
       need_write_barrier = false;
     } else {
       __ push(a1);
       __ CallRuntime(Runtime::kNewFunctionContext, 1);
     }
-    function_in_register = false;
+    function_in_register_a1 = 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();
     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()) {
@@ skipping 12 matching lines @@
         } else if (FLAG_debug_code) {
           Label done;
           __ JumpIfInNewSpace(cp, a0, &done);
           __ Abort(kExpectedNewSpaceObject);
           __ bind(&done);
         }
       }
     }
   }
 
+  PrepareForBailoutForId(BailoutId::Prologue(), NO_REGISTERS);
+  // Function register is trashed in case we bailout here. But since that
+  // could happen only when we allocate a context the value of
+  // |function_in_register_a1| is correct.
+
   // Possibly set up a local binding to the this function which is used in
   // derived constructors with super calls.
   Variable* this_function_var = scope()->this_function_var();
   if (this_function_var != nullptr) {
     Comment cmnt(masm_, "[ This function");
-    if (!function_in_register) {
+    if (!function_in_register_a1) {
       __ lw(a1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-      // The write barrier clobbers register again, keep is marked as such.
+      // The write barrier clobbers register again, keep it marked as such.
     }
     SetVar(this_function_var, a1, a2, a3);
   }
 
   Variable* new_target_var = scope()->new_target_var();
   if (new_target_var != nullptr) {
     Comment cmnt(masm_, "[ new.target");
 
     // Get the frame pointer for the calling frame.
     __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
 
     // Skip the arguments adaptor frame if it exists.
     Label check_frame_marker;
     __ lw(a1, MemOperand(a2, StandardFrameConstants::kContextOffset));
     __ Branch(&check_frame_marker, ne, a1,
               Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
     __ lw(a2, MemOperand(a2, StandardFrameConstants::kCallerFPOffset));
 
     // Check the marker in the calling frame.
     __ bind(&check_frame_marker);
     __ lw(a1, MemOperand(a2, StandardFrameConstants::kMarkerOffset));
+    function_in_register_a1 = false;
 
     Label non_construct_frame, done;
     __ Branch(&non_construct_frame, ne, a1,
               Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
 
     __ lw(v0,
           MemOperand(a2, ConstructFrameConstants::kOriginalConstructorOffset));
     __ Branch(&done);
 
     __ bind(&non_construct_frame);
@@ skipping 11 matching lines @@
 
     int num_parameters = info->scope()->num_parameters();
     int offset = num_parameters * kPointerSize;
 
     __ Addu(a3, fp,
             Operand(StandardFrameConstants::kCallerSPOffset + offset));
     __ li(a2, Operand(Smi::FromInt(num_parameters)));
     __ li(a1, Operand(Smi::FromInt(rest_index)));
     __ li(a0, Operand(Smi::FromInt(language_mode())));
     __ Push(a3, a2, a1, a0);
+    function_in_register_a1 = false;
 
     RestParamAccessStub stub(isolate());
     __ CallStub(&stub);
 
     SetVar(rest_param, v0, a1, a2);
   }
 
   Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.
     Comment cmnt(masm_, "[ Allocate arguments object");
-    if (!function_in_register) {
+    if (!function_in_register_a1) {
       // Load this again, if it's used by the local context below.
       __ lw(a3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     } else {
       __ mov(a3, a1);
     }
     // Receiver is just before the parameters on the caller's stack.
     int num_parameters = info->scope()->num_parameters();
     int offset = num_parameters * kPointerSize;
     __ Addu(a2, fp,
            Operand(StandardFrameConstants::kCallerSPOffset + offset));
@@ skipping 5008 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS