Make sampling heap profiler work for short living scripts.

src/profiler/sampling-heap-profiler.cc

 // Copyright 2015 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/profiler/sampling-heap-profiler.h"
 
 #include <stdint.h>
 #include <memory>
 #include "src/api.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 186 matching lines @@
   Local<v8::String> script_name =
       ToApiHandle<v8::String>(isolate_->factory()->InternalizeUtf8String(""));
   int line = v8::AllocationProfile::kNoLineNumberInfo;
   int column = v8::AllocationProfile::kNoColumnNumberInfo;
   std::vector<v8::AllocationProfile::Allocation> allocations;
   allocations.reserve(node->allocations_.size());
   if (node->script_id_ != v8::UnboundScript::kNoScriptId) {
     // Cannot use std::map<T>::at because it is not available on android.
     auto non_const_scripts = const_cast<std::map<int, Script*>&>(scripts);
     Script* script = non_const_scripts[node->script_id_];
-    if (script->name()->IsName()) {
-      Name* name = Name::cast(script->name());
-      script_name = ToApiHandle<v8::String>(
-          isolate_->factory()->InternalizeUtf8String(names_->GetName(name)));
+    if (script) {
+      if (script->name()->IsName()) {
+        Name* name = Name::cast(script->name());

[Michael Achenbach, 2016/03/24 09:18:25]

Experimental code-coverage reports this block as not executed on x64. I see
three cases:
1) Is there really no test that exercises this, then please consider adding a v8
stand-alone test.
2) Is it executed in some other configuration? No action required.
3) It is executed in some test on x64? Then code coverage has a bug.

+        script_name = ToApiHandle<v8::String>(
+            isolate_->factory()->InternalizeUtf8String(names_->GetName(name)));
+      }
+      Handle<Script> script_handle(script);
+      line = 1 + Script::GetLineNumber(script_handle, node->script_position_);
+      column =
+          1 + Script::GetColumnNumber(script_handle, node->script_position_);
     }
-    Handle<Script> script_handle(script);
-
-    line = 1 + Script::GetLineNumber(script_handle, node->script_position_);
-    column = 1 + Script::GetColumnNumber(script_handle, node->script_position_);
     for (auto alloc : node->allocations_) {
       allocations.push_back(ScaleSample(alloc.first, alloc.second));
     }
   }
 
   profile->nodes().push_back(v8::AllocationProfile::Node(
       {ToApiHandle<v8::String>(
            isolate_->factory()->InternalizeUtf8String(node->name_)),
        script_name, node->script_id_, node->script_position_, line, column,
        std::vector<v8::AllocationProfile::Node*>(), allocations}));
@@ skipping 26 matching lines @@
   auto profile = new v8::internal::AllocationProfile();
 
   TranslateAllocationNode(profile, &profile_root_, scripts);
 
   return profile;
 }
 
 
 }  // namespace internal
 }  // namespace v8