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

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 172 matching lines @@
       __ Branch(&loop, ne, a0, Operand(sp));
       __ Pop(a0, a1);
     } else {
       __ Subu(sp, sp, Operand(slots * kPointerSize));
     }
   }
 
   if (info()->saves_caller_doubles()) {
     SaveCallerDoubles();
   }
+  return !is_aborted();
+}
+
+
+void LCodeGen::DoPrologue(LPrologue* instr) {
+  Comment(";;; Prologue begin");
 
   // Possibly allocate a local context.
-  int heap_slots = info()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
-  if (heap_slots > 0) {
+  if (info()->scope()->num_heap_slots() > 0) {
     Comment(";;; Allocate local context");
     bool need_write_barrier = true;
     // Argument to NewContext is the function, which is in a1.
-    DCHECK(!info()->scope()->is_script_scope());
-    if (heap_slots <= FastNewContextStub::kMaximumSlots) {
-      FastNewContextStub stub(isolate(), heap_slots);
+    int slots = info()->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
+    Safepoint::DeoptMode deopt_mode = Safepoint::kNoLazyDeopt;
+    if (info()->scope()->is_script_scope()) {
+      __ push(a1);
+      __ Push(info()->scope()->GetScopeInfo(info()->isolate()));
+      __ CallRuntime(Runtime::kNewScriptContext, 2);
+      deopt_mode = Safepoint::kLazyDeopt;
+    } 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);
     }
-    RecordSafepoint(Safepoint::kNoLazyDeopt);
+    RecordSafepoint(deopt_mode);
+
     // Context is returned in both 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 = scope()->num_parameters();
     int first_parameter = 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 @@
           Label done;
           __ JumpIfInNewSpace(cp, a0, &done);
           __ Abort(kExpectedNewSpaceObject);
           __ bind(&done);
         }
       }
     }
     Comment(";;; End allocate local context");
   }
 
-  // Trace the call.
-  if (FLAG_trace && info()->IsOptimizing()) {
-    // We have not executed any compiled code yet, so cp still holds the
-    // incoming context.
-    __ CallRuntime(Runtime::kTraceEnter, 0);
-  }
-  return !is_aborted();
+  Comment(";;; Prologue end");
 }
 
 
 void LCodeGen::GenerateOsrPrologue() {
   // Generate the OSR entry prologue at the first unknown OSR value, or if there
   // are none, at the OSR entrypoint instruction.
   if (osr_pc_offset_ >= 0) return;
 
   osr_pc_offset_ = masm()->pc_offset();
 
@@ skipping 5665 matching lines @@
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8