- Make sure to fail early if an non-stacktrace is passed into the VM

runtime/vm/exceptions.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/exceptions.h"
 
 #include "platform/address_sanitizer.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 343 matching lines @@
   const Stacktrace& full_stacktrace = Stacktrace::Handle(
       Stacktrace::New(full_code_array, full_pc_offset_array));
   full_stacktrace.SetCatchStacktrace(full_catch_code_array,
                                      full_catch_pc_offset_array);
   return full_stacktrace.raw();
 }
 
 
 static void ThrowExceptionHelper(Isolate* isolate,
                                  const Instance& incoming_exception,
-                                 const Instance& existing_stacktrace,
+                                 const Stacktrace& existing_stacktrace,
                                  const bool is_rethrow) {
   bool use_preallocated_stacktrace = false;
   Instance& exception = Instance::Handle(isolate, incoming_exception.raw());
   if (exception.IsNull()) {
     exception ^= Exceptions::Create(Exceptions::kNullThrown,
                                     Object::empty_array());
   } else if (exception.raw() == isolate->object_store()->out_of_memory() ||
              exception.raw() == isolate->object_store()->stack_overflow()) {
     use_preallocated_stacktrace = true;
   }
@@ skipping 44 matching lines @@
         BuildStackTrace(isolate, &frame_builder);
 
         // Create arrays for code and pc_offset tuples of each frame.
         code_array = Array::MakeArray(frame_builder.code_list());
         pc_offset_array = Array::MakeArray(frame_builder.pc_offset_list());
       }
       if (existing_stacktrace.IsNull()) {
         stacktrace = Stacktrace::New(code_array, pc_offset_array);
       } else {
         ASSERT(is_rethrow);
-        stacktrace ^= existing_stacktrace.raw();
+        stacktrace = existing_stacktrace.raw();
         if (pc_offset_array.Length() != 0) {
           // Skip the first frame during a rethrow. This is the catch clause
           // with the rethrow statement, which is not part of the original
           // trace a rethrow is supposed to preserve.
           stacktrace.Append(code_array, pc_offset_array, 1);
         }
         // Since we are re throwing and appending to the existing stack trace
         // we clear out the catch trace collected in the existing stack trace
         // as that trace will not be valid anymore.
         stacktrace.SetCatchStacktrace(Object::empty_array(),
@@ skipping 126 matching lines @@
 
 void Exceptions::Throw(Isolate* isolate, const Instance& exception) {
   // Do not notify debugger on stack overflow and out of memory exceptions.
   // The VM would crash when the debugger calls back into the VM to
   // get values of variables.
   if (exception.raw() != isolate->object_store()->out_of_memory() &&
       exception.raw() != isolate->object_store()->stack_overflow()) {
     isolate->debugger()->SignalExceptionThrown(exception);
   }
   // Null object is a valid exception object.
-  ThrowExceptionHelper(isolate, exception, Instance::Handle(isolate), false);
+  ThrowExceptionHelper(isolate, exception, Stacktrace::Handle(isolate), false);
 }
 
 
 void Exceptions::ReThrow(Isolate* isolate,
                          const Instance& exception,
-                         const Instance& stacktrace) {
+                         const Stacktrace& stacktrace) {
   // Null object is a valid exception object.
   ThrowExceptionHelper(isolate, exception, stacktrace, true);
 }
 
 
 void Exceptions::PropagateError(const Error& error) {
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate->top_exit_frame_info() != 0);
   if (error.IsUnhandledException()) {
     // If the error object represents an unhandled exception, then
     // rethrow the exception in the normal fashion.
     const UnhandledException& uhe = UnhandledException::Cast(error);
     const Instance& exc = Instance::Handle(isolate, uhe.exception());
-    const Instance& stk = Instance::Handle(isolate, uhe.stacktrace());
+    const Stacktrace& stk = Stacktrace::Handle(isolate, uhe.stacktrace());
     Exceptions::ReThrow(isolate, exc, stk);
   } else {
     // Return to the invocation stub and return this error object.  The
     // C++ code which invoked this dart sequence can check and do the
     // appropriate thing.
     uword handler_pc = 0;
     uword handler_sp = 0;
     uword handler_fp = 0;
     FindErrorHandler(&handler_pc, &handler_sp, &handler_fp);
     JumpToExceptionHandler(isolate, handler_pc, handler_sp, handler_fp, error,
@@ skipping 147 matching lines @@
 
 // Throw JavascriptCompatibilityError exception.
 void Exceptions::ThrowJavascriptCompatibilityError(const char* msg) {
   const Array& exc_args = Array::Handle(Array::New(1));
   const String& msg_str = String::Handle(String::New(msg));
   exc_args.SetAt(0, msg_str);
   Exceptions::ThrowByType(Exceptions::kJavascriptCompatibilityError, exc_args);
 }
 
 }  // namespace dart