S390: [debug] implement intuitive semantics for stepping over await call.

src/s390/builtins-s390.cc

Index: src/s390/builtins-s390.cc
diff --git a/src/s390/builtins-s390.cc b/src/s390/builtins-s390.cc
index 8aca9da0d0b3235988960e6eecfb8e5e5aa306ac..6927a2ccc8103259150f7490abaa1435bd685ced 100644
--- a/src/s390/builtins-s390.cc
+++ b/src/s390/builtins-s390.cc
@@ -711,21 +711,25 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
 
   // Flood function if we are stepping.
-  Label skip_flooding;
+  Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
+  Label stepping_prepared;
   ExternalReference step_in_enabled =
       ExternalReference::debug_step_in_enabled_address(masm->isolate());
   __ mov(ip, Operand(step_in_enabled));
   __ LoadlB(ip, MemOperand(ip));
   __ CmpP(ip, Operand::Zero());
-  __ beq(&skip_flooding);
-  {
-    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
-    __ Push(r3, r4, r6);
-    __ CallRuntime(Runtime::kDebugPrepareStepInIfStepping);
-    __ Pop(r3, r4);
-    __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
-  }
-  __ bind(&skip_flooding);
+  __ bne(&prepare_step_in_if_stepping);
+
+  // Flood function if we need to continue stepping in the suspended generator.
+
+  ExternalReference debug_suspended_generator =
+      ExternalReference::debug_suspended_generator_address(masm->isolate());
+
+  __ mov(ip, Operand(debug_suspended_generator));
+  __ LoadP(ip, MemOperand(ip));
+  __ CmpP(ip, r3);
+  __ beq(&prepare_step_in_suspended_generator);
+  __ bind(&stepping_prepared);
 
   // Push receiver.
   __ LoadP(ip, FieldMemOperand(r3, JSGeneratorObject::kReceiverOffset));
@@ -830,6 +834,26 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       __ Jump(r5);
     }
   }
+
+  __ bind(&prepare_step_in_if_stepping);
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+    __ Push(r3, r4, r6);
+    __ CallRuntime(Runtime::kDebugPrepareStepInIfStepping);
+    __ Pop(r3, r4);
+    __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
+  }
+  __ b(&stepping_prepared);
+
+  __ bind(&prepare_step_in_suspended_generator);
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+    __ Push(r3, r4);
+    __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
+    __ Pop(r3, r4);
+    __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
+  }
+  __ b(&stepping_prepared);
 }
 
 void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {