Debugger: prepare code for debugging on a per-function basis.

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 8136 matching lines @@
   // Parse and allocate variables.
   // Use the same AstValueFactory for creating strings in the sub-compilation
   // step, but don't transfer ownership to target_info.
   ParseInfo parse_info(zone(), target);
   parse_info.set_ast_value_factory(
       top_info()->parse_info()->ast_value_factory());
   parse_info.set_ast_value_factory_owned(false);
 
   CompilationInfo target_info(&parse_info);
   Handle<SharedFunctionInfo> target_shared(target->shared());
+  if (target_shared->HasDebugInfo()) {
+    TraceInline(target, caller, "target is being debugged");
+    return false;
+  }
   if (!Compiler::ParseAndAnalyze(target_info.parse_info())) {
     if (target_info.isolate()->has_pending_exception()) {
       // Parse or scope error, never optimize this function.
       SetStackOverflow();
       target_shared->DisableOptimization(kParseScopeError);
     }
     TraceInline(target, caller, "parse failure");
     return false;
   }
 
@@ skipping 5154 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8