DWARF and unwind support for AOT assembly output.

runtime/vm/flags.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/flags.h"
 
 #include "platform/assert.h"
 #include "vm/json_stream.h"
 #include "vm/os.h"
 
@@ skipping 422 matching lines @@
     }
     if (unrecognized_count > 0) {
       OS::PrintErr("\n");
       exit(255);
     }
   }
   if (FLAG_print_flags) {
     PrintFlags();
   }
 
+  if (FLAG_dwarf_stack_traces) {
+    // The Dart standard requires the output of StackTrace.toString to include
+    // all pending activations with precise source locations (i.e., to expand
+    // inlined frames and provide line and column numbers).
+    OS::PrintErr(
+        "Warning: This VM has been configured to produce stack traces "

[Cutch, 2017/03/15 14:54:13]

Is this necessary?

[rmacnak, 2017/03/16 17:50:11]

Maybe in the stack trace instead, but we should be clear the VM isn't running
Dart with this flag.

+        "that violate the Dart standard.\n");
+  }
+
   initialized_ = true;
   return true;
 }
 
+
 bool Flags::SetFlag(const char* name, const char* value, const char** error) {
   Flag* flag = Lookup(name);
   if (flag == NULL) {
     *error = "Cannot set flag: flag not found";
     return false;
   }
   if (!SetFlagFromString(flag, value)) {
     *error = "Cannot set flag: invalid value";
     return false;
   }
@@ skipping 61 matching lines @@
   JSONObject jsobj(js);
   jsobj.AddProperty("type", "FlagList");
   JSONArray jsarr(&jsobj, "flags");
   for (intptr_t i = 0; i < num_flags_; ++i) {
     PrintFlagToJSONArray(&jsarr, flags_[i]);
   }
 }
 #endif  // !PRODUCT
 
 }  // namespace dart