X87: [debugger] flood function for stepping before calling it.

src/x87/macro-assembler-x87.cc

Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index 09dd474f0af3d9616de5a9ae52e5246bbd841a79..0b28c64512cb9226b3da7647b09b8b5189834734 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -1952,16 +1952,63 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
 }
 
 
-void MacroAssembler::InvokeCode(const Operand& code, Register new_target,
-                                const ParameterCount& expected,
-                                const ParameterCount& actual, InvokeFlag flag,
-                                const CallWrapper& call_wrapper) {
+void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
+                                             const ParameterCount& expected,
+                                             const ParameterCount& actual) {
+  Label skip_flooding;
+  ExternalReference debug_step_action =
+      ExternalReference::debug_last_step_action_address(isolate());
+  cmpb(Operand::StaticVariable(debug_step_action), StepIn);
+  j(not_equal, &skip_flooding);
+  {
+    FrameScope frame(this,
+                     has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
+    if (expected.is_reg()) {
+      SmiTag(expected.reg());
+      Push(expected.reg());
+    }
+    if (actual.is_reg()) {
+      SmiTag(actual.reg());
+      Push(actual.reg());
+    }
+    if (new_target.is_valid()) {
+      Push(new_target);
+    }
+    Push(fun);
+    Push(fun);
+    CallRuntime(Runtime::kDebugPrepareStepInIfStepping, 1);
+    Pop(fun);
+    if (new_target.is_valid()) {
+      Pop(new_target);
+    }
+    if (actual.is_reg()) {
+      Pop(actual.reg());
+      SmiUntag(actual.reg());
+    }
+    if (expected.is_reg()) {
+      Pop(expected.reg());
+      SmiUntag(expected.reg());
+    }
+  }
+  bind(&skip_flooding);
+}
+
+
+void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
+                                        const ParameterCount& expected,
+                                        const ParameterCount& actual,
+                                        InvokeFlag flag,
+                                        const CallWrapper& call_wrapper) {
   // You can't call a function without a valid frame.
   DCHECK(flag == JUMP_FUNCTION || has_frame());
-
-  // Ensure new target is passed in the correct register. Otherwise clear the
-  // appropriate register in case new target is not given.
+  DCHECK(function.is(edi));
   DCHECK_IMPLIES(new_target.is_valid(), new_target.is(edx));
+
+  if (call_wrapper.NeedsDebugStepCheck()) {
+    FloodFunctionIfStepping(function, new_target, expected, actual);
+  }
+
+  // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
     mov(edx, isolate()->factory()->undefined_value());
   }
@@ -1971,6 +2018,10 @@ void MacroAssembler::InvokeCode(const Operand& code, Register new_target,
   InvokePrologue(expected, actual, &done, &definitely_mismatches, flag,
                  Label::kNear, call_wrapper);
   if (!definitely_mismatches) {
+    // We call indirectly through the code field in the function to
+    // allow recompilation to take effect without changing any of the
+    // call sites.
+    Operand code = FieldOperand(function, JSFunction::kCodeEntryOffset);
     if (flag == CALL_FUNCTION) {
       call_wrapper.BeforeCall(CallSize(code));
       call(code);
@@ -1998,8 +2049,7 @@ void MacroAssembler::InvokeFunction(Register fun, Register new_target,
   SmiUntag(ebx);
 
   ParameterCount expected(ebx);
-  InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset), new_target,
-             expected, actual, flag, call_wrapper);
+  InvokeFunctionCode(edi, new_target, expected, actual, flag, call_wrapper);
 }
 
 
@@ -2014,8 +2064,7 @@ void MacroAssembler::InvokeFunction(Register fun,
   DCHECK(fun.is(edi));
   mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
-  InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset), no_reg, expected,
-             actual, flag, call_wrapper);
+  InvokeFunctionCode(edi, no_reg, expected, actual, flag, call_wrapper);
 }
 
 
@@ -2039,8 +2088,7 @@ void MacroAssembler::InvokeBuiltin(int native_context_index, InvokeFlag flag,
   // parameter count to avoid emitting code to do the check.
   ParameterCount expected(0);
   GetBuiltinFunction(edi, native_context_index);
-  InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset), no_reg, expected,
-             expected, flag, call_wrapper);
+  InvokeFunctionCode(edi, no_reg, expected, expected, flag, call_wrapper);
 }
 
 
@@ -2053,16 +2101,6 @@ void MacroAssembler::GetBuiltinFunction(Register target,
 }
 
 
-void MacroAssembler::GetBuiltinEntry(Register target,
-                                     int native_context_index) {
-  DCHECK(!target.is(edi));
-  // Load the JavaScript builtin function from the builtins object.
-  GetBuiltinFunction(edi, native_context_index);
-  // Load the code entry point from the function into the target register.
-  mov(target, FieldOperand(edi, JSFunction::kCodeEntryOffset));
-}
-
-
 void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
   if (context_chain_length > 0) {
     // Move up the chain of contexts to the context containing the slot.