[vm, compiler] Fix incorrect register save in breakpoint stub.

Bug introduced in 1e24fe7d69.

Symbolize stub frames.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/47039
Change-Id: Ida3535a01923085cd48a2801ed9b868bfef7418b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212026
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>

runtime/observatory/tests/service/breakpoint_gc_test.dart

@@ -0,0 +1,53 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'test_helper.dart';
+import 'service_test_common.dart';
+
+const int LINE_A = 16;
+const int LINE_B = 19;
+const int LINE_C = 22;
+const String file = "breakpoint_gc_test.dart";
+
+foo() => 42;
+
+testeeMain() {
+  foo(); // static call
+
+  dynamic list = [1, 2, 3];
+  list.clear(); // instance call
+  print(list);
+
+  dynamic local = list; // debug step check = runtime call
+  return local;
+}
+
+Future forceGC(isolate) async {
+  await isolate.invokeRpcNoUpgrade("_collectAllGarbage", {});
+}
+
+var tests = <IsolateTest>[
+  hasPausedAtStart,
+  setBreakpointAtUriAndLine(file, LINE_A), // at `foo()`
+  setBreakpointAtUriAndLine(file, LINE_B), // at `list.clear()`
+  setBreakpointAtUriAndLine(file, LINE_C), // at `local = list`
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_A),
+  forceGC, // Should not crash
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_B),
+  forceGC, // Should not crash
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_C),
+  forceGC, // Should not crash
+  resumeIsolate,
+];
+
+main(args) {
+  runIsolateTestsSynchronous(args, tests,
+      testeeConcurrent: testeeMain, pause_on_start: true);
+}

runtime/observatory/tests/service/service_kernel.status

@@ -52,6 +52,7 @@ break_on_function_child_isolate_test: SkipByDesign # Debugger is disabled in AOT
 break_on_function_many_child_isolates_test: SkipByDesign # Debugger is disabled in AOT mode.
 break_on_function_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_async_break_test: SkipByDesign # Debugger is disabled in AOT mode.
+breakpoint_gc_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_package_parts_class_file_uri_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_package_parts_class_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_parts_class_test: SkipByDesign # Debugger is disabled in AOT mode.

runtime/observatory_2/tests/service_2/breakpoint_gc_test.dart

@@ -0,0 +1,53 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'test_helper.dart';
+import 'service_test_common.dart';
+
+const int LINE_A = 16;
+const int LINE_B = 19;
+const int LINE_C = 22;
+const String file = "breakpoint_gc_test.dart";
+
+foo() => 42;
+
+testeeMain() {
+  foo(); // static call
+
+  dynamic list = [1, 2, 3];
+  list.clear(); // instance call
+  print(list);
+
+  dynamic local = list; // debug step check = runtime call
+  return local;
+}
+
+Future forceGC(isolate) async {
+  await isolate.invokeRpcNoUpgrade("_collectAllGarbage", {});
+}
+
+var tests = <IsolateTest>[
+  hasPausedAtStart,
+  setBreakpointAtUriAndLine(file, LINE_A), // at `foo()`
+  setBreakpointAtUriAndLine(file, LINE_B), // at `list.clear()`
+  setBreakpointAtUriAndLine(file, LINE_C), // at `local = list`
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_A),
+  forceGC, // Should not crash
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_B),
+  forceGC, // Should not crash
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_C),
+  forceGC, // Should not crash
+  resumeIsolate,
+];
+
+main(args) {
+  runIsolateTestsSynchronous(args, tests,
+      testeeConcurrent: testeeMain, pause_on_start: true);
+}

runtime/observatory_2/tests/service_2/service_2_kernel.status

@@ -52,6 +52,7 @@ break_on_function_child_isolate_test: SkipByDesign # Debugger is disabled in AOT
 break_on_function_many_child_isolates_test: SkipByDesign # Debugger is disabled in AOT mode.
 break_on_function_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_async_break_test: SkipByDesign # Debugger is disabled in AOT mode.
+breakpoint_gc_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_package_parts_class_file_uri_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_package_parts_class_test: SkipByDesign # Debugger is disabled in AOT mode.
 breakpoint_in_parts_class_test: SkipByDesign # Debugger is disabled in AOT mode.

runtime/vm/compiler/stub_code_compiler_x64.cc

@@ -2726,13 +2726,11 @@ void StubCodeCompiler::GenerateUnoptStaticCallBreakpointStub(
   __ Stop("No debugging in PRODUCT mode");
 #else
   __ EnterStubFrame();
-  __ pushq(RDX);           // Preserve receiver.
   __ pushq(RBX);           // Preserve IC data.
   __ pushq(Immediate(0));  // Result slot.
   __ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
   __ popq(CODE_REG);  // Original stub.
   __ popq(RBX);       // Restore IC data.
-  __ popq(RDX);       // Restore receiver.
   __ LeaveStubFrame();
 
   __ movq(RAX, FieldAddress(CODE_REG, target::Code::entry_point_offset()));

runtime/vm/stack_frame.cc

@@ -162,24 +162,12 @@ bool StackFrame::IsStubFrame() const {
 const char* StackFrame::ToCString() const {
   ASSERT(thread_ == Thread::Current());
   Zone* zone = Thread::Current()->zone();
-  if (IsDartFrame()) {
-    const Code& code = Code::Handle(zone, LookupDartCode());
-    ASSERT(!code.IsNull());
-    const auto& owner = Object::Handle(
-        zone, WeakSerializationReference::UnwrapIfTarget(code.owner()));
-    ASSERT(!owner.IsNull());
-    auto const opt = code.IsFunctionCode() && code.is_optimized() ? "*" : "";
-    auto const owner_name =
-        owner.IsFunction() ? Function::Cast(owner).ToFullyQualifiedCString()
-                           : owner.ToCString();
-    return zone->PrintToString("[%-8s : sp(%#" Px ") fp(%#" Px ") pc(%#" Px
-                               ") %s%s ]",
-                               GetName(), sp(), fp(), pc(), opt, owner_name);
-  } else {
-    return zone->PrintToString("[%-8s : sp(%#" Px ") fp(%#" Px ") pc(%#" Px
-                               ")]",
-                               GetName(), sp(), fp(), pc());
-  }
+  const Code& code = Code::Handle(zone, GetCodeObject());
+  ASSERT(!code.IsNull());
+  const char* name =
+      code.QualifiedName(NameFormattingParams(Object::kInternalName));
+  return zone->PrintToString("  pc 0x%" Pp " fp 0x%" Pp " sp 0x%" Pp " %s",
+                             pc(), fp(), sp(), name);
 }
 
 void ExitFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {