Add dead CodeRegionTable for tracking overwritten Dart code

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 10374 matching lines @@
 RawCode* Code::LookupCode(uword pc) {
   return LookupCodeInIsolate(Isolate::Current(), pc);
 }
 
 
 RawCode* Code::LookupCodeInVmIsolate(uword pc) {
   return LookupCodeInIsolate(Dart::vm_isolate(), pc);
 }
 
 
+// Given a pc and a timestamp, lookup the code.
+RawCode* Code::FindCode(uword pc, int64_t timestamp) {
+  Code& code = Code::Handle(Code::LookupCode(pc));
+  if (!code.IsNull() && (code.compile_timestamp() == timestamp) &&
+      (code.EntryPoint() == pc)) {
+    // Found code in isolate.
+    return code.raw();
+  }
+  code ^= Code::LookupCodeInVmIsolate(pc);
+  if (!code.IsNull() && (code.compile_timestamp() == timestamp) &&
+      (code.EntryPoint() == pc)) {
+    // Found code in VM isolate.
+    return code.raw();
+  }
+  return Code::null();
+}
+
+
 intptr_t Code::GetTokenIndexOfPC(uword pc) const {
   intptr_t token_pos = -1;
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
   for (intptr_t i = 0; i < descriptors.Length(); i++) {
     if (descriptors.PC(i) == pc) {
       token_pos = descriptors.TokenPos(i);
       break;
     }
   }
   return token_pos;
@@ skipping 73 matching lines @@
     ASSERT(obj.IsFunction());
     // Dart function.
     return Function::Cast(obj).QualifiedUserVisibleName();
   }
 }
 
 
 void Code::PrintToJSONStream(JSONStream* stream, bool ref) const {
   JSONObject jsobj(stream);
   jsobj.AddProperty("type", JSONType(ref));
-  jsobj.AddPropertyF("id", "code/%" Px "", EntryPoint());
+  jsobj.AddPropertyF("id", "code/%" Px64"-%" Px "", compile_timestamp(),
+                     EntryPoint());
   jsobj.AddPropertyF("start", "%" Px "", EntryPoint());
   jsobj.AddPropertyF("end", "%" Px "", EntryPoint() + Size());
   jsobj.AddProperty("is_optimized", is_optimized());
   jsobj.AddProperty("is_alive", is_alive());
+  jsobj.AddProperty("kind", "Dart");
   const String& name = String::Handle(Name());
   const String& user_name = String::Handle(UserName());
   const char* name_prefix = is_optimized() ? "*" : "";
   jsobj.AddPropertyF("name", "%s%s", name_prefix, name.ToCString());
   jsobj.AddPropertyF("user_name", "%s%s", name_prefix, user_name.ToCString());
   const Object& obj = Object::Handle(owner());
   if (obj.IsFunction()) {
     jsobj.AddProperty("function", obj);
   } else {
     // Generate a fake function reference.
     JSONObject func(&jsobj, "function");
     func.AddProperty("type", "@Function");
     func.AddProperty("kind", "Stub");
-    func.AddPropertyF("id", "stub/functions/%" Pd "", EntryPoint());
+    func.AddPropertyF("id", "functions/stub-%" Pd "", EntryPoint());
     func.AddProperty("user_name", user_name.ToCString());
     func.AddProperty("name", name.ToCString());
   }
   if (ref) {
     return;
   }
   JSONArray jsarr(&jsobj, "disassembly");
   if (is_alive()) {
     // Only disassemble alive code objects.
     DisassembleToJSONStream formatter(jsarr);
@@ skipping 7118 matching lines @@
   return "_MirrorReference";
 }
 
 
 void MirrorReference::PrintToJSONStream(JSONStream* stream, bool ref) const {
   Instance::PrintToJSONStream(stream, ref);
 }
 
 
 }  // namespace dart