VM: Service isolate under precompilation.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 93c5502dc51f97242fe8ab8c9d35585d075c02b6..1dfdcdf3877d16c956c79c8dd6fd40d30e3f843b 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -13425,24 +13425,35 @@ bool Code::FindRawCodeVisitor::FindObject(RawObject* raw_obj) const {
 }
 
 
+bool Code::SlowFindRawCodeVisitor::FindObject(RawObject* raw_obj) const {
+  return RawCode::ContainsPC(raw_obj, pc_);
+}
+
+
 RawCode* Code::LookupCodeInIsolate(Isolate* isolate, uword pc) {
   ASSERT((isolate == Isolate::Current()) || (isolate == Dart::vm_isolate()));
+  if (isolate->heap() == NULL) {
+    return Code::null();
+  }
   NoSafepointScope no_safepoint;
-  FindRawCodeVisitor visitor(pc);
-  RawInstructions* instr;
+  // TODO(johnmccutchan): Make lookup without a back pointer faster and use for
+  // both cases.
   if (Dart::IsRunningPrecompiledCode()) {
-    // TODO(johnmccutchan): Make code lookup work when running precompiled.
-    UNIMPLEMENTED();
+    SlowFindRawCodeVisitor visitor(pc);
+    RawObject* needle = isolate->heap()->FindOldObject(&visitor);
+    if (needle != Code::null()) {
+      return static_cast<RawCode*>(needle);
+    }
     return Code::null();
-  }
-  if (isolate->heap() == NULL) {
+  } else {
+    FindRawCodeVisitor visitor(pc);
+    RawInstructions* instr;
+    instr = isolate->heap()->FindObjectInCodeSpace(&visitor);
+    if (instr != Instructions::null()) {
+      return Instructions::Handle(instr).code();
+    }
     return Code::null();
   }
-  instr = isolate->heap()->FindObjectInCodeSpace(&visitor);
-  if (instr != Instructions::null()) {
-    return Instructions::Handle(instr).code();
-  }
-  return Code::null();
 }