[d8] Add compile benchmarking options

Add --compile-only and --repeat-compile=N options for benchmarking
compilation performance.

Change-Id: Ibcdce94ef0d2a24374badeca114f44b693adb2ac
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2827903
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73987}

src/d8/d8.cc

@@ -696,6 +696,12 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
     Local<Context> context(isolate->GetCurrentContext());
     ScriptOrigin origin(isolate, name);
 
+    for (int i = 1; i < options.repeat_compile; ++i) {
+      HandleScope handle_scope(isolate);
+      if (CompileString<Script>(isolate, context, source, origin).IsEmpty()) {
+        return false;
+      }
+    }
     Local<Script> script;
     if (!CompileString<Script>(isolate, context, source, origin)
              .ToLocal(&script)) {
@@ -710,6 +716,9 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
       StoreInCodeCache(isolate, source, cached_data);
       delete cached_data;
     }
+    if (options.compile_only) {
+      return true;
+    }
     maybe_result = script->Run(realm);
     if (options.code_cache_options ==
         ShellOptions::CodeCacheOptions::kProduceCacheAfterExecute) {
@@ -4058,6 +4067,12 @@ bool Shell::SetOptions(int argc, char* argv[]) {
     } else if (strncmp(argv[i], "--web-snapshot-config=", 22) == 0) {
       options.web_snapshot_config = argv[i] + 22;
       argv[i] = nullptr;
+    } else if (strcmp(argv[i], "--compile-only") == 0) {
+      options.compile_only = true;
+      argv[i] = nullptr;
+    } else if (strncmp(argv[i], "--repeat-compile=", 17) == 0) {
+      options.repeat_compile = atoi(argv[i] + 17);
+      argv[i] = nullptr;
 #ifdef V8_FUZZILLI
     } else if (strcmp(argv[i], "--no-fuzzilli-enable-builtins-coverage") == 0) {
       options.fuzzilli_enable_builtins_coverage = false;

src/d8/d8.h

@@ -403,6 +403,8 @@ class ShellOptions {
       "enable-system-instrumentation", false};
   DisallowReassignment<const char*> web_snapshot_config = {
       "web-snapshot-config", nullptr};
+  DisallowReassignment<bool> compile_only = {"compile-only", false};
+  DisallowReassignment<int> repeat_compile = {"repeat-compile", 1};
 };
 
 class Shell : public i::AllStatic {