Debugger: correctly redirect code with no stack check.

src/full-codegen/ia32/full-codegen-ia32.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_IA32
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 332 matching lines @@
   if (scope()->HasIllegalRedeclaration()) {
     Comment cmnt(masm_, "[ Declarations");
     scope()->VisitIllegalRedeclaration(this);
 
   } else {
     PrepareForBailoutForId(BailoutId::FunctionEntry(), NO_REGISTERS);
     { Comment cmnt(masm_, "[ Declarations");
       VisitDeclarations(scope()->declarations());
     }
 
+    // Assert that the declarations do not use ICs. Otherwise the debugger
+    // won't be able to redirect a PC at an IC to the correct IC in newly
+    // recompiled code.
+    DCHECK_EQ(0, ic_total_count_);
+
     { Comment cmnt(masm_, "[ Stack check");
       PrepareForBailoutForId(BailoutId::Declarations(), NO_REGISTERS);
       Label ok;
       ExternalReference stack_limit
           = ExternalReference::address_of_stack_limit(isolate());
       __ cmp(esp, Operand::StaticVariable(stack_limit));
       __ j(above_equal, &ok, Label::kNear);
       __ call(isolate()->builtins()->StackCheck(), RelocInfo::CODE_TARGET);
       __ bind(&ok);
     }
@@ skipping 2279 matching lines @@
     Label assign;
     MemOperand location = VarOperand(var, ecx);
     __ mov(edx, location);
     __ cmp(edx, isolate()->factory()->the_hole_value());
     __ j(not_equal, &assign, Label::kNear);
     __ push(Immediate(var->name()));
     __ CallRuntime(Runtime::kThrowReferenceError, 1);
     __ bind(&assign);
     EmitStoreToStackLocalOrContextSlot(var, location);
 
+    printf("let ");

[mvstanton, 2015/07/30 13:44:07]

This should go, right?

[Yang, 2015/07/30 13:45:58]

Correct. Thanks for catching this!

+    var->name()->Print();
+
   } else if (var->mode() == CONST && op != Token::INIT_CONST) {
     // Assignment to const variable needs a write barrier.
     DCHECK(!var->IsLookupSlot());
     DCHECK(var->IsStackAllocated() || var->IsContextSlot());
     Label const_error;
     MemOperand location = VarOperand(var, ecx);
     __ mov(edx, location);
     __ cmp(edx, isolate()->factory()->the_hole_value());
     __ j(not_equal, &const_error, Label::kNear);
     __ push(Immediate(var->name()));
     __ CallRuntime(Runtime::kThrowReferenceError, 1);
     __ bind(&const_error);
     __ CallRuntime(Runtime::kThrowConstAssignError, 0);
 
+    printf("con ");
+    var->name()->Print();
+
   } else if (var->is_this() && op == Token::INIT_CONST) {
     // Initializing assignment to const {this} needs a write barrier.
     DCHECK(var->IsStackAllocated() || var->IsContextSlot());
     Label uninitialized_this;
     MemOperand location = VarOperand(var, ecx);
     __ mov(edx, location);
     __ cmp(edx, isolate()->factory()->the_hole_value());
     __ j(equal, &uninitialized_this);
     __ push(Immediate(var->name()));
     __ CallRuntime(Runtime::kThrowReferenceError, 1);
@@ skipping 2665 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32