[misctools] Add cold jsc start test

3 files changed, 210 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index d7e8d953e..b2377f761 100644
--- a/.gitignore
+++ b/.gitignore
@@ -116,3 +116,6 @@ src/bun.js/debug-bindings-obj
 failing-tests.txt
 test.txt
 myscript.sh
+
+cold-jsc-start
+cold-jsc-start.d
diff --git a/Makefile b/Makefile
index 874a35116..7bdba3f6e 100644
--- a/Makefile
+++ b/Makefile
@@ -1827,6 +1827,22 @@ copy-to-bun-release-dir-bin:
 PACKAGE_MAP = --pkg-begin async_io $(BUN_DIR)/src/io/io_darwin.zig --pkg-begin bun $(BUN_DIR)/src/bun_redirect.zig --pkg-end --pkg-end --pkg-begin javascript_core $(BUN_DIR)/src/jsc.zig --pkg-begin bun $(BUN_DIR)/src/bun_redirect.zig --pkg-end --pkg-end --pkg-begin bun $(BUN_DIR)/src/bun_redirect.zig --pkg-end
 
 
+.PHONY: cold-jsc-start
+cold-jsc-start:
+	$(CXX_WITH_CCACHE) $(CLANG_FLAGS) \
+		$(MACOS_MIN_FLAG) \
+		$(OPTIMIZATION_LEVEL) \
+		-MMD \
+		-fno-exceptions \
+		-fno-rtti \
+		-ferror-limit=1000 \
+		$(LIBICONV_PATH) \
+		$(DEFAULT_LINKER_FLAGS) \
+		$(PLATFORM_LINKER_FLAGS) \
+		$(ICU_FLAGS) \
+		$(JSC_FILES) \
+		misctools/cold-jsc-start.cpp -o cold-jsc-start
+
 .PHONY: vendor-without-npm
 vendor-without-npm: node-fallbacks runtime_js fallback_decoder bun_error mimalloc picohttp zlib boringssl libarchive lolhtml sqlite usockets uws tinycc c-ares
 
diff --git a/misctools/cold-jsc-start.cpp b/misctools/cold-jsc-start.cpp
new file mode 100644
index 000000000..2703d7016
--- /dev/null
+++ b/misctools/cold-jsc-start.cpp
@@ -0,0 +1,191 @@
+// print how long each step took
+#define VERBOSE
+
+//
+// This loads up a JavaScriptCore global object which only has a "write"
+// global function and then calls eval
+//
+//
+// Usage:
+//  ./cold-jsc-start <file>
+//  ./cold-jsc-start -e "write('hey')"
+//
+#include "root.h"
+
+#include <wtf/FileSystem.h>
+
+#include <JavaScriptCore/JSGlobalObject.h>
+
+#include <JavaScriptCore/JSArrayBufferView.h>
+#include <JavaScriptCore/JSArrayBufferViewInlines.h>
+
+#include <JavaScriptCore/Completion.h>
+#include <JavaScriptCore/InitializeThreading.h>
+#include <unistd.h>
+#include <wtf/Stopwatch.h>
+
+using namespace JSC;
+
+JSC_DEFINE_HOST_FUNCTION(jsFunctionWrite, (JSC::JSGlobalObject * globalObject,
+                                           JSC::CallFrame *callframe)) {
+
+  if (callframe->argumentCount() < 1)
+    return JSValue::encode(jsUndefined());
+
+  JSValue arg1 = callframe->argument(0);
+  JSValue toWriteArg = callframe->argument(1);
+  auto &vm = globalObject->vm();
+  auto scope = DECLARE_CATCH_SCOPE(vm);
+
+  int32_t fd = STDOUT_FILENO;
+  if (callframe->argumentCount() > 1) {
+    fd = arg1.toInt32(globalObject);
+    RETURN_IF_EXCEPTION(scope, encodedJSValue());
+  } else {
+    toWriteArg = arg1;
+  }
+
+  if (auto *buffer = jsDynamicCast<JSC::JSArrayBufferView *>(toWriteArg)) {
+    auto *data = buffer->vector();
+    auto length = buffer->byteLength();
+    auto written = write(fd, data, length);
+    return JSValue::encode(jsNumber(written));
+  }
+
+  auto string = toWriteArg.toWTFString(globalObject);
+  RETURN_IF_EXCEPTION(scope, encodedJSValue());
+  auto utf8 = string.utf8();
+  auto length = utf8.length();
+  auto written = write(fd, utf8.data(), length);
+  return JSValue::encode(jsNumber(written));
+}
+
+int main(int argc, char **argv) {
+  if (argc < 2) {
+    fprintf(stderr, "Usage: %s <file>\n", argv[0]);
+    return 1;
+  }
+#ifdef VERBOSE
+  auto stopwatch = Stopwatch::create();
+  stopwatch->start();
+#endif
+
+  {
+    WTF::initializeMainThread();
+    JSC::initialize();
+    {
+      JSC::Options::AllowUnfinalizedAccessScope scope;
+
+      JSC::Options::useConcurrentJIT() = true;
+      // JSC::Options::useSigillCrashAnalyzer() = true;
+      JSC::Options::useWebAssembly() = true;
+      JSC::Options::useSourceProviderCache() = true;
+      // JSC::Options::useUnlinkedCodeBlockJettisoning() = false;
+      JSC::Options::exposeInternalModuleLoader() = true;
+      JSC::Options::useSharedArrayBuffer() = true;
+      JSC::Options::useJIT() = true;
+      JSC::Options::useBBQJIT() = true;
+      JSC::Options::useJITCage() = false;
+      JSC::Options::useShadowRealm() = true;
+      JSC::Options::useResizableArrayBuffer() = true;
+      JSC::Options::showPrivateScriptsInStackTraces() = true;
+      JSC::Options::useSetMethods() = true;
+      JSC::Options::assertOptionsAreCoherent();
+    }
+  }
+
+#ifdef VERBOSE
+
+  fprintf(stderr, "JSC::Initialize took %f ms\n",
+          stopwatch->elapsedTime().milliseconds());
+  stopwatch->reset();
+  stopwatch->start();
+#endif
+
+  auto &vm = JSC::VM::create(JSC::HeapType::Large).leakRef();
+  vm.heap.acquireAccess();
+
+#ifdef VERBOSE
+  fprintf(stderr, "JSC::VM::create took %f ms\n",
+          stopwatch->elapsedTime().milliseconds());
+  stopwatch->reset();
+  stopwatch->start();
+#endif
+
+  JSC::JSLockHolder locker(vm);
+  auto *globalObject = JSC::JSGlobalObject::create(
+      vm, JSC::JSGlobalObject::createStructure(vm, JSC::jsNull()));
+
+#ifdef VERBOSE
+  fprintf(stderr, "JSC::JSGlobalObject::create took %f ms\n",
+          stopwatch->elapsedTime().milliseconds());
+  stopwatch->reset();
+  stopwatch->start();
+#endif
+
+  JSC::gcProtect(globalObject);
+  globalObject->putDirectNativeFunction(
+      vm, globalObject,
+      PropertyName(JSC::Identifier::fromString(vm, "write"_s)), 0,
+      jsFunctionWrite, ImplementationVisibility::Public, JSC::NoIntrinsic,
+      JSC::PropertyAttribute::ReadOnly | 0);
+
+  vm.ref();
+  if (argc > 2) {
+    auto source = JSC::makeSource(WTF::String::fromUTF8(argv[argc - 1]),
+                                  SourceOrigin(WTF::URL("file://eval.js"_s)),
+                                  "eval.js"_s);
+
+    NakedPtr<Exception> evaluationException;
+    JSValue returnValue =
+        JSC::profiledEvaluate(globalObject, ProfilingReason::API, source,
+                              globalObject, evaluationException);
+
+#ifdef VERBOSE
+    fprintf(stderr, "\neval took %f ms\n",
+            stopwatch->elapsedTime().milliseconds());
+    stopwatch->reset();
+
+#endif
+
+    if (evaluationException) {
+      fprintf(
+          stderr, "Exception: %s\n",
+          evaluationException->value().toWTFString(globalObject).utf8().data());
+      return 1;
+    } else {
+      return 0;
+    }
+  }
+
+  WTF::String fileURLString = WTF::String::fromUTF8(argv[argc - 1]);
+
+  if (auto contents = WTF::FileSystemImpl::readEntireFile(fileURLString)) {
+    auto source =
+        JSC::makeSource(WTF::String::fromUTF8(contents.value()),
+                        SourceOrigin(WTF::URL(fileURLString)), fileURLString);
+
+    NakedPtr<Exception> evaluationException;
+    JSValue returnValue =
+        JSC::profiledEvaluate(globalObject, ProfilingReason::API, source,
+                              globalObject, evaluationException);
+
+#ifdef VERBOSE
+    fprintf(stderr, "eval took %f ms\n",
+            stopwatch->elapsedTime().milliseconds());
+    stopwatch->reset();
+#endif
+
+    if (evaluationException) {
+      fprintf(
+          stderr, "Exception: %s\n",
+          evaluationException->value().toWTFString(globalObject).utf8().data());
+      return 1;
+    } else {
+      return 0;
+    }
+  } else {
+    fprintf(stderr, "Could not read file %s\n", argv[argc - 1]);
+    return 1;
+  }
+}