Use old assertion text script in precompiled mode

runtime/lib/errors.cc

 // Copyright (c) 2012, 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/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 // Scan the stack until we hit the first function in the _AssertionError
 // class. We then return the next frame's script taking inlining into account.
 static RawScript* FindScript(DartFrameIterator* iterator) {
+  if (FLAG_precompiled_runtime) {
+    // The precompiled runtime faces two issues in recovering the correct
+    // assertion text. First, the precompiled runtime does not include
+    // the inlining meta-data so we cannot walk the inline-aware stack trace.
+    // Second, the script text itself is missing so whatever script is returned
+    // from here will be missing the assertion expression text.
+    iterator->NextFrame();  // Skip _AssertionError._checkAssertion frame
+    return Exceptions::GetCallerScript(iterator);
+  }
   StackFrame* stack_frame = iterator->NextFrame();
   Code& code = Code::Handle();
   Function& func = Function::Handle();
   const Class& assert_error_class = Class::Handle(
         Library::LookupCoreClass(Symbols::AssertionError()));
   ASSERT(!assert_error_class.IsNull());
   bool hit_assertion_error = false;
   while (stack_frame != NULL) {
     code ^= stack_frame->LookupDartCode();
     if (code.is_optimized()) {
@@ skipping 141 matching lines @@
 
 // Rethrow an error with a stacktrace.
 DEFINE_NATIVE_ENTRY(Async_rethrow, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, error, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, stacktrace, arguments->NativeArgAt(1));
   Exceptions::ReThrow(thread, error, stacktrace);
   return Object::null();
 }
 
 }  // namespace dart