Introduce intrinsic to expose debug state to generated code.

src/x64/full-codegen-x64.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_X64
 
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 4004 matching lines @@
   __ movp(rax, result_operand);
 
   __ bind(&return_result);
   // Drop temp values from the stack, and restore context register.
   __ addp(rsp, Immediate(3 * kPointerSize));
   __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   context()->Plug(rax);
 }
 
 
+void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
+  ASSERT(expr->arguments()->length() == 0);
+  ExternalReference debug_is_active =
+      ExternalReference::debug_is_active_address(isolate());
+  __ Move(kScratchRegister, debug_is_active);
+  __ movzxbp(rax, Operand(kScratchRegister, 0));
+  __ Integer32ToSmi(rax, rax);
+  context()->Plug(rax);
+}
+
+
 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   if (expr->function() != NULL &&
       expr->function()->intrinsic_type == Runtime::INLINE) {
     Comment cmnt(masm_, "[ InlineRuntimeCall");
     EmitInlineRuntimeCall(expr);
     return;
   }
 
   Comment cmnt(masm_, "[ CallRuntime");
   ZoneList<Expression*>* args = expr->arguments();
@@ skipping 775 matching lines @@
   ASSERT_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64