Changed StackZone and ApiZone to be containers for Zone.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index ef99695a4e31dfa328a75b49db5f2b66df15b2d8..fe121b45e6321948bd5f0591e15ea22f77bdc0f3 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -200,7 +200,7 @@ Dart_Handle Api::NewError(const char* format, ...) {
   intptr_t len = OS::VSNPrint(NULL, 0, format, args);
   va_end(args);
 
-  char* buffer = zone.Alloc<char>(len + 1);
+  char* buffer = isolate->current_zone()->Alloc<char>(len + 1);
   va_list args2;
   va_start(args2, format);
   OS::VSNPrint(buffer, (len + 1), format, args2);
@@ -410,7 +410,7 @@ DART_EXPORT Dart_Handle Dart_Error(const char* format, ...) {
   intptr_t len = OS::VSNPrint(NULL, 0, format, args);
   va_end(args);
 
-  char* buffer = zone.Alloc<char>(len + 1);
+  char* buffer = isolate->current_zone()->Alloc<char>(len + 1);
   va_list args2;
   va_start(args2, format);
   OS::VSNPrint(buffer, (len + 1), format, args2);
@@ -432,7 +432,7 @@ DART_EXPORT Dart_Handle Dart_NewApiError(const char* format, ...) {
   intptr_t len = OS::VSNPrint(NULL, 0, format, args);
   va_end(args);
 
-  char* buffer = zone.Alloc<char>(len + 1);
+  char* buffer = isolate->current_zone()->Alloc<char>(len + 1);
   va_list args2;
   va_start(args2, format);
   OS::VSNPrint(buffer, (len + 1), format, args2);
@@ -457,13 +457,14 @@ DART_EXPORT Dart_Handle Dart_NewUnhandledExceptionError(Dart_Handle exception) {
 
 DART_EXPORT Dart_Handle Dart_PropagateError(Dart_Handle handle) {
   Isolate* isolate = Isolate::Current();
-  CHECK_ISOLATE(isolate);
-  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(handle));
-  if (!obj.IsError()) {
-    return Api::NewError(
-        "%s expects argument 'handle' to be an error handle.  "
-        "Did you forget to check Dart_IsError first?",
-        CURRENT_FUNC);
+  {
+    const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(handle));

[Ivan Posva, 2012/10/15 20:32:17]

How about adding a comment explaining that we are preventing this handle to live
across the destruction of zones below. Otherwise the motivation of this extra
block is unclear.

[Tom Ball, 2012/10/15 21:48:47]

Done.

+    if (!obj.IsError()) {
+      return Api::NewError(
+          "%s expects argument 'handle' to be an error handle.  "
+          "Did you forget to check Dart_IsError first?",
+          CURRENT_FUNC);
+    }
   }
   if (isolate->top_exit_frame_info() == 0) {
     // There are no dart frames on the stack so it would be illegal to
@@ -474,10 +475,15 @@ DART_EXPORT Dart_Handle Dart_PropagateError(Dart_Handle handle) {
   // Unwind all the API scopes till the exit frame before propagating.
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
-  state->UnwindScopes(isolate->top_exit_frame_info());
-  Exceptions::PropagateError(Error::Cast(obj));
+  Object* error;

[Ivan Posva, 2012/10/15 20:32:17]

How about Error*?Then you can avoid the cast below and you already know it is an
error.

[Tom Ball, 2012/10/15 21:48:47]

Done.

+  {
+    NoGCScope no_gc;

[Ivan Posva, 2012/10/15 20:32:17]

// We need to preserve the error object across the destruction of zones. Ensure
// that no GCs can be triggered and preserve the raw object. Before creating a
// valid handle in the surviving zone.

Or something similar.

[Tom Ball, 2012/10/15 21:48:47]

Done.

+    RawObject* raw_obj = Api::UnwrapHandle(handle);
+    state->UnwindScopes(isolate->top_exit_frame_info());
+    error = &Object::Handle(raw_obj);
+  }
+  Exceptions::PropagateError(Error::Cast(*error));
   UNREACHABLE();
-
   return Api::NewError("Cannot reach here.  Internal error.");
 }
 
@@ -1142,7 +1148,7 @@ DART_EXPORT void Dart_ExitScope() {
 
 
 DART_EXPORT uint8_t* Dart_ScopeAllocate(intptr_t size) {
-  ApiZone* zone;
+  Zone* zone;
   Isolate* isolate = Isolate::Current();
   if (isolate != NULL) {
     ApiState* state = isolate->api_state();
@@ -3897,10 +3903,12 @@ DART_EXPORT Dart_Handle Dart_SetNativeInstanceField(Dart_Handle obj,
 
 DART_EXPORT Dart_Handle Dart_ThrowException(Dart_Handle exception) {
   Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Instance& excp = Api::UnwrapInstanceHandle(isolate, exception);
-  if (excp.IsNull()) {
-    RETURN_TYPE_ERROR(isolate, exception, Instance);
+  CHECK_ISOLATE(isolate);
+  {
+    const Instance& excp = Api::UnwrapInstanceHandle(isolate, exception);
+    if (excp.IsNull()) {
+      RETURN_TYPE_ERROR(isolate, exception, Instance);
+    }
   }
   if (isolate->top_exit_frame_info() == 0) {
     // There are no dart frames on the stack so it would be illegal to
@@ -3911,7 +3919,15 @@ DART_EXPORT Dart_Handle Dart_ThrowException(Dart_Handle exception) {
   // exception.
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
-  state->UnwindScopes(isolate->top_exit_frame_info());
+  Object* exc;
+  {
+    NoGCScope no_gc;
+    RawObject* raw_obj = Api::UnwrapHandle(exception);
+    state->UnwindScopes(isolate->top_exit_frame_info());
+    exc = &Object::Handle(raw_obj);
+  }
+  Exceptions::PropagateError(Error::Cast(*exc));

[Ivan Posva, 2012/10/15 20:32:17]

?

[Tom Ball, 2012/10/15 21:48:47]

Removed.

+  const Instance& excp = Api::UnwrapInstanceHandle(isolate, exception);

[Ivan Posva, 2012/10/15 20:32:17]

The exception handle is very likely invalid at this point. As it was probably
allocated in the zone that was just removed.

[Tom Ball, 2012/10/15 21:48:47]

Fixed reference.

   Exceptions::Throw(excp);
   return Api::NewError("Exception was not thrown, internal error");
 }
@@ -3921,14 +3937,15 @@ DART_EXPORT Dart_Handle Dart_ReThrowException(Dart_Handle exception,
                                               Dart_Handle stacktrace) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
-  DARTSCOPE(isolate);
-  const Instance& excp = Api::UnwrapInstanceHandle(isolate, exception);
-  if (excp.IsNull()) {
-    RETURN_TYPE_ERROR(isolate, exception, Instance);
-  }
-  const Instance& stk = Api::UnwrapInstanceHandle(isolate, stacktrace);
-  if (stk.IsNull()) {
-    RETURN_TYPE_ERROR(isolate, stacktrace, Instance);
+  {
+    const Instance& excp = Api::UnwrapInstanceHandle(isolate, exception);
+    if (excp.IsNull()) {
+      RETURN_TYPE_ERROR(isolate, exception, Instance);
+    }
+    const Instance& stk = Api::UnwrapInstanceHandle(isolate, stacktrace);
+    if (stk.IsNull()) {
+      RETURN_TYPE_ERROR(isolate, stacktrace, Instance);
+    }
   }
   if (isolate->top_exit_frame_info() == 0) {
     // There are no dart frames on the stack so it would be illegal to
@@ -3939,7 +3956,18 @@ DART_EXPORT Dart_Handle Dart_ReThrowException(Dart_Handle exception,
   // exception.
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
-  state->UnwindScopes(isolate->top_exit_frame_info());
+  Object* exc;
+  Object* stk_trace;
+  {
+    NoGCScope no_gc;
+    RawObject* raw_exception = Api::UnwrapHandle(exception);
+    RawObject* raw_stacktrace = Api::UnwrapHandle(stacktrace);
+    state->UnwindScopes(isolate->top_exit_frame_info());
+    exc = &Object::Handle(raw_exception);
+    stk_trace = &Object::Handle(raw_stacktrace);
+  }
+  const Instance& excp = Instance::Cast(*const_cast<Object*>(exc));
+  const Instance& stk = Instance::Cast(*const_cast<Object*>(stk_trace));
   Exceptions::ReThrow(excp, stk);
   return Api::NewError("Exception was not re thrown, internal error");
 }
@@ -4423,7 +4451,7 @@ DART_EXPORT void Dart_GetPprofSymbolInfo(void** buffer, int* buffer_size) {
     pprof_symbol_generator->WriteToMemory(debug_region);
     *buffer_size = debug_region->size();
     if (*buffer_size != 0) {
-      ApiZone* zone = Api::TopScope(isolate)->zone();
+      Zone* zone = Api::TopScope(isolate)->zone();
       *buffer = reinterpret_cast<void*>(zone->AllocUnsafe(*buffer_size));
       memmove(*buffer, debug_region->data(), *buffer_size);
     } else {