Do not swallow compilation errors when setting breakpoint

runtime/vm/debugger.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/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 1620 matching lines @@
 }
 
 
 RawFunction* Debugger::FindBestFit(const Script& script,
                                    intptr_t token_pos) {
   Class& cls = Class::Handle(isolate_);
   Array& functions = Array::Handle(isolate_);
   GrowableObjectArray& closures = GrowableObjectArray::Handle(isolate_);
   Function& function = Function::Handle(isolate_);
   Function& best_fit = Function::Handle(isolate_);
+  Error& error = Error::Handle(isolate_);
 
   const ClassTable& class_table = *isolate_->class_table();
   const intptr_t num_classes = class_table.NumCids();
   for (intptr_t i = 1; i < num_classes; i++) {
     if (class_table.HasValidClassAt(i)) {
       cls = class_table.At(i);
       // Note: if this class has been parsed and finalized already,
       // we need to check the functions of this class even if
       // it is defined in a differenct 'script'. There could
       // be mixin functions from the given script in this class.
       // However, if this class is not parsed yet (not finalized),
       // we can ignore it and avoid the side effect of parsing it.
       if ((cls.script() != script.raw()) && !cls.is_finalized()) {
         continue;
       }
       // Parse class definition if not done yet.
-      cls.EnsureIsFinalized(isolate_);
+      error = cls.EnsureIsFinalized(isolate_);
+      if (!error.IsNull()) {
+        // Ignore functions in this class.
+        // TODO(hausner): Should we propagate this error? How?
+        // EnsureIsFinalized only returns an error object if there
+        // is no longjump base on the stack.
+        continue;
+      }
       functions = cls.functions();
       if (!functions.IsNull()) {
         const intptr_t num_functions = functions.Length();
         for (intptr_t pos = 0; pos < num_functions; pos++) {
           function ^= functions.At(pos);
           ASSERT(!function.IsNull());
           if (FunctionContains(function, script, token_pos)) {
             SelectBestFit(&best_fit, &function);
           }
         }
@@ skipping 106 matching lines @@
       } else {
         cbpt->Disable();
       }
     }
     cbpt = cbpt->next();
   }
 }
 
 
 RawError* Debugger::OneTimeBreakAtEntry(const Function& target_function) {
-  SourceBreakpoint* bpt = SetBreakpointAtEntry(target_function);
-  if (bpt != NULL) {
-    bpt->SetIsOneShot();
+  LongJumpScope jump;
+  if (setjmp(*jump.Set()) == 0) {
+    SourceBreakpoint* bpt = SetBreakpointAtEntry(target_function);
+    if (bpt != NULL) {
+      bpt->SetIsOneShot();
+    }
+    return Error::null();
+  } else {
+    return isolate_->object_store()->sticky_error();
   }
-  return Error::null();
 }
 
 
 SourceBreakpoint* Debugger::SetBreakpointAtEntry(
       const Function& target_function) {
   ASSERT(!target_function.IsNull());
   if (!target_function.is_debuggable()) {
     return NULL;
   }
   const Script& script = Script::Handle(target_function.script());
@@ skipping 855 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart