Deoptimize functions before setting breakpoints

runtime/vm/code_generator.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/code_generator.h"
 
 #include "vm/code_index_table.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
@@ skipping 1186 matching lines @@
 }
 
 
 // Only unoptimized code has invocation counter threshold checking.
 // Once the invocation counter threshold is reached any entry into the
 // unoptimized code is redirected to this function.
 DEFINE_RUNTIME_ENTRY(OptimizeInvokedFunction, 1) {
   ASSERT(arguments.Count() ==
          kOptimizeInvokedFunctionRuntimeEntry.argument_count());
   const Function& function = Function::CheckedHandle(arguments.At(0));
+  if (isolate->debugger()->IsActive()) {
+    // We cannot set breakpoints in optimized code, so do not optimize
+    // the function.
+    function.set_usage_counter(0);
+    return;
+  }
   if (function.deoptimization_counter() >=
       FLAG_deoptimization_counter_threshold) {
     // TODO(srdjan): Investigate excessive deoptimization.
     function.set_usage_counter(0);
     return;
   }
   if (function.HasOptimizedCode()) {
     // The caller has been already optimized.
     // TODO(srdjan): This is a significant slowdown, the caller is probably in
     // a loop. Maybe test if the code has been optimized before calling.
@@ skipping 211 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart