[web snapshot] Name scripts better

Give the "phantom" script containing the web snapshot functions the same
name as the original script.

Bug: v8:11525
Change-Id: Iae77d58152642256560ceb3688bc2b3d0d9800be
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3394707Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78643}

src/codegen/compiler.cc

@@ -2858,7 +2858,8 @@ MaybeHandle<SharedFunctionInfo> GetSharedFunctionInfoForScriptImpl(
       }
     }
     if (magic_matches) {
-      return Compiler::GetSharedFunctionInfoForWebSnapshot(isolate, source);
+      return Compiler::GetSharedFunctionInfoForWebSnapshot(
+          isolate, source, script_details.name_obj);
     }
   }
 
@@ -3153,7 +3154,8 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
 
 // static
 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForWebSnapshot(
-    Isolate* isolate, Handle<String> source) {
+    Isolate* isolate, Handle<String> source,
+    MaybeHandle<Object> maybe_script_name) {
   // This script won't hold the functions created from the web snapshot;
   // reserving space only for the top-level SharedFunctionInfo is enough.
   Handle<WeakFixedArray> shared_function_infos =
@@ -3161,6 +3163,12 @@ Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForWebSnapshot(
   Handle<Script> script = isolate->factory()->NewScript(source);
   script->set_type(Script::TYPE_WEB_SNAPSHOT);
   script->set_shared_function_infos(*shared_function_infos);
+  Handle<Object> script_name;
+  if (maybe_script_name.ToHandle(&script_name) && script_name->IsString()) {
+    script->set_name(String::cast(*script_name));
+  } else {
+    script->set_name(*isolate->factory()->empty_string());
+  }
 
   Handle<SharedFunctionInfo> shared =
       isolate->factory()->NewSharedFunctionInfoForWebSnapshot();

src/codegen/compiler.h

@@ -215,7 +215,7 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
       const ScriptDetails& script_details, ScriptStreamingData* streaming_data);
 
   static Handle<SharedFunctionInfo> GetSharedFunctionInfoForWebSnapshot(
-      Isolate* isolate, Handle<String> source);
+      Isolate* isolate, Handle<String> source, MaybeHandle<Object> script_name);
 
   // Create a shared function info object for the given function literal
   // node (the code may be lazily compiled).

src/web-snapshot/web-snapshot.cc

@@ -1001,6 +1001,7 @@ bool WebSnapshotDeserializer::UseWebSnapshot(
     Handle<Script> snapshot_as_script) {
   Handle<String> source =
       handle(String::cast(snapshot_as_script->source()), isolate_);
+  script_name_ = handle(snapshot_as_script->name(), isolate_);
   if (source->IsExternalOneByteString()) {
     const v8::String::ExternalOneByteStringResource* resource =
         ExternalOneByteString::cast(*source).resource();
@@ -1121,9 +1122,7 @@ bool WebSnapshotDeserializer::DeserializeScript() {
             NewStringType::kNormal, static_cast<int>(remaining_bytes))
             .ToLocalChecked();
 
-    ScriptOrigin origin(v8_isolate, v8::String::NewFromUtf8Literal(
-                                        v8_isolate, "(web snapshot)",
-                                        NewStringType::kInternalized));
+    ScriptOrigin origin(v8_isolate, Utils::ToLocal(script_name_));
 
     ScriptCompiler::Source script_source(source, origin);
     Local<UnboundScript> script;

src/web-snapshot/web-snapshot.h

@@ -281,6 +281,7 @@ class V8_EXPORT WebSnapshotDeserializer
   Handle<WeakFixedArray> shared_function_infos_;
   Handle<ObjectHashTable> shared_function_info_table_;
   Handle<Script> script_;
+  Handle<Object> script_name_;
 
   uint32_t string_count_ = 0;
   uint32_t map_count_ = 0;