[debugger] infrastructure for side-effect-free debug-evaluate.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 26a3dae1c646632481657f937a30e867672ecbc6..39b1768055bcddce097df648184136a1e05fa216 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -4211,8 +4211,8 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   DCHECK(function.is(rdi));
   DCHECK_IMPLIES(new_target.is_valid(), new_target.is(rdx));
 
-  if (call_wrapper.NeedsDebugStepCheck()) {
-    FloodFunctionIfStepping(function, new_target, expected, actual);
+  if (call_wrapper.NeedsDebugHookCheck()) {
+    CheckDebugHook(function, new_target, expected, actual);
   }
 
   // Clear the new.target register if not given.
@@ -4312,17 +4312,15 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
   }
 }
 
-
-void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
-                                             const ParameterCount& expected,
-                                             const ParameterCount& actual) {
-  Label skip_flooding;
-  ExternalReference last_step_action =
-      ExternalReference::debug_last_step_action_address(isolate());
-  Operand last_step_action_operand = ExternalOperand(last_step_action);
-  STATIC_ASSERT(StepFrame > StepIn);
-  cmpb(last_step_action_operand, Immediate(StepIn));
-  j(less, &skip_flooding);
+void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
+                                    const ParameterCount& expected,
+                                    const ParameterCount& actual) {
+  Label skip_hook;
+  ExternalReference debug_hook_active =
+      ExternalReference::debug_hook_on_function_call_address(isolate());
+  Operand debug_hook_active_operand = ExternalOperand(debug_hook_active);
+  cmpb(debug_hook_active_operand, Immediate(0));
+  j(equal, &skip_hook);
   {
     FrameScope frame(this,
                      has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
@@ -4339,7 +4337,7 @@ void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
     }
     Push(fun);
     Push(fun);
-    CallRuntime(Runtime::kDebugPrepareStepInIfStepping);
+    CallRuntime(Runtime::kDebugOnFunctionCall);
     Pop(fun);
     if (new_target.is_valid()) {
       Pop(new_target);
@@ -4353,7 +4351,7 @@ void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
       SmiToInteger64(expected.reg(), expected.reg());
     }
   }
-  bind(&skip_flooding);
+  bind(&skip_hook);
 }
 
 void MacroAssembler::StubPrologue(StackFrame::Type type) {