Rewrite snapshot_creator in Rust

12 files changed, 98 insertions, 240 deletions

diff --git a/cli/BUILD.gn b/cli/BUILD.gn
index 20a5b2dee..7f19f8b95 100644
--- a/cli/BUILD.gn
+++ b/cli/BUILD.gn
@@ -5,7 +5,7 @@ import("//build_extra/flatbuffers/rust/rust_flatbuffer.gni")
 import("//build_extra/rust/rust.gni")
 import("//third_party/v8/gni/snapshot_toolchain.gni")
 import("//third_party/v8/gni/v8.gni")
-import("../deno.gni")
+import("deno.gni")
 
 main_extern = [
   {
diff --git a/deno.gni b/cli/deno.gni
index a260edd11..dabcd43ca 100644
--- a/deno.gni
+++ b/cli/deno.gni
@@ -16,7 +16,8 @@ template("bundle") {
     ]
     depfile = out_dir + out_name + ".d"
     args = [
-      rebase_path("//third_party/node_modules/rollup/bin/rollup", root_build_dir),
+      rebase_path("//third_party/node_modules/rollup/bin/rollup",
+                  root_build_dir),
       "-c",
       rebase_path("//rollup.config.js", root_build_dir),
       "-i",
@@ -45,8 +46,7 @@ template("snapshot") {
                              "testonly",
                              "deps",
                            ])
-    # TODO(ry) Rewrite snapshot_creator in Rust.
-    tool = "//core/libdeno:snapshot_creator"
+    tool = "//core:snapshot_creator"
     visibility = [ ":*" ]  # Only targets in this file can depend on this.
     snapshot_out_bin = "$target_gen_dir/$target_name.bin"
     inputs = [
diff --git a/core/BUILD.gn b/core/BUILD.gn
index bf9d910c0..0f1eba8ca 100644
--- a/core/BUILD.gn
+++ b/core/BUILD.gn
@@ -7,6 +7,7 @@ group("default") {
     ":deno_core_http_bench",
     ":deno_core_http_bench_test",
     ":deno_core_test",
+    ":snapshot_creator",
   ]
 }
 
@@ -77,3 +78,14 @@ rust_test("deno_core_http_bench_test") {
   extern = http_bench_extern
   extern_rlib = http_bench_extern_rlib
 }
+
+rust_executable("snapshot_creator") {
+  source_root = "snapshot_creator.rs"
+  extern = [
+    {
+      label = ":deno"
+      crate_name = "deno"
+      crate_type = "rlib"
+    },
+  ]
+}
diff --git a/core/Cargo.toml b/core/Cargo.toml
index b22bf7fe9..c41863da0 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -13,6 +13,10 @@ repository = "https://github.com/denoland/deno"
 [lib]
 path = "lib.rs"
 
+[[bin]]
+name = "snapshot_creator"
+path = "snapshot_creator.rs"
+
 [dependencies]
 futures = "0.1.27"
 lazy_static = "1.3.0"
diff --git a/core/libdeno/BUILD.gn b/core/libdeno/BUILD.gn
index 31a5be640..10ec4bf91 100644
--- a/core/libdeno/BUILD.gn
+++ b/core/libdeno/BUILD.gn
@@ -1,5 +1,4 @@
 # Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-import("//deno.gni")
 import("//third_party/v8/gni/v8.gni")
 
 config("deno_config") {
@@ -50,8 +49,6 @@ v8_source_set("libdeno") {
     "deno.h",
     "exceptions.cc",
     "exceptions.h",
-    "file_util.cc",
-    "file_util.h",
     "internal.h",
     "modules.cc",
   ]
@@ -71,39 +68,21 @@ v8_static_library("libdeno_static_lib") {
   configs = [ ":deno_config" ]
 }
 
-v8_executable("snapshot_creator") {
-  sources = [
-    "snapshot_creator.cc",
-  ]
-  deps = [
-    ":libdeno",
-  ]
-  configs = [ ":deno_config" ]
-}
-
 v8_executable("libdeno_test") {
   testonly = true
   sources = [
-    "file_util_test.cc",
     "libdeno_test.cc",
     "modules_test.cc",
     "test.cc",
   ]
   deps = [
     ":libdeno",
-    ":snapshot_test",
     "//testing/gtest:gtest",
   ]
   data = [
-    "$target_gen_dir/snapshot_test.bin",
+    "libdeno_test.js",
   ]
-  snapshot_path = rebase_path(data[0], root_build_dir)
-  defines = [ "SNAPSHOT_PATH=\"$snapshot_path\"" ]
+  js_path = rebase_path(data[0])
+  defines = [ "JS_PATH=\"$js_path\"" ]
   configs = [ ":deno_config" ]
 }
-
-# Generates $target_gen_dir/snapshot_test.bin
-snapshot("snapshot_test") {
-  testonly = true
-  source_root = "libdeno_test.js"
-}
diff --git a/core/libdeno/api.cc b/core/libdeno/api.cc
index 13057aeae..1515bca51 100644
--- a/core/libdeno/api.cc
+++ b/core/libdeno/api.cc
@@ -11,7 +11,6 @@
 
 #include "deno.h"
 #include "exceptions.h"
-#include "file_util.h"
 #include "internal.h"
 
 extern "C" {
diff --git a/core/libdeno/file_util.cc b/core/libdeno/file_util.cc
deleted file mode 100644
index 256f4f257..000000000
--- a/core/libdeno/file_util.cc
+++ /dev/null
@@ -1,90 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-#include <inttypes.h>
-#include <limits.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fstream>
-#include <iterator>
-#include <string>
-
-#ifdef __APPLE__
-#include <mach-o/dyld.h>
-#endif
-
-#ifdef _WIN32
-#include <windows.h>
-#endif
-
-#include "file_util.h"
-
-namespace deno {
-
-bool ReadFileToString(const char* fn, std::string* contents) {
-  std::ifstream file(fn, std::ios::binary);
-  if (file.fail()) {
-    return false;
-  }
-  contents->assign(std::istreambuf_iterator<char>{file}, {});
-  return !file.fail();
-}
-
-std::string Basename(std::string const& filename) {
-  for (auto it = filename.rbegin(); it != filename.rend(); ++it) {
-    char ch = *it;
-    if (ch == '\\' || ch == '/') {
-      return std::string(it.base(), filename.end());
-    }
-  }
-  return filename;
-}
-
-// Returns the directory component from a filename. The returned path always
-// ends with a slash. This function does not understand Windows drive letters.
-std::string Dirname(std::string const& filename) {
-  for (auto it = filename.rbegin(); it != filename.rend(); ++it) {
-    char ch = *it;
-    if (ch == '\\' || ch == '/') {
-      return std::string(filename.begin(), it.base());
-    }
-  }
-  return std::string("./");
-}
-
-// Returns the full path the currently running executable.
-// This implementation is very basic. Caveats:
-//   * OS X: fails if buffer is too small, does not retry with a bigger buffer.
-//   * Windows: ANSI only, no unicode. Fails if path is longer than 260 chars.
-bool ExePath(std::string* path) {
-#ifdef _WIN32
-  // Windows only.
-  char exe_buf[MAX_PATH];
-  DWORD len = GetModuleFileNameA(NULL, exe_buf, sizeof exe_buf);
-  if (len == 0 || len == sizeof exe_buf) {
-    return false;
-  }
-#else
-#ifdef __APPLE__
-  // OS X only.
-  char link_buf[PATH_MAX * 2];  // Exe may be longer than MAX_PATH, says Apple.
-  uint32_t len = sizeof link_buf;
-  if (_NSGetExecutablePath(link_buf, &len) < 0) {
-    return false;
-  }
-#else
-  // Linux only.
-  static const char* link_buf = "/proc/self/exe";
-#endif
-  // Linux and OS X.
-  char exe_buf[PATH_MAX];
-  char* r = realpath(link_buf, exe_buf);
-  if (r == NULL) {
-    return false;
-  }
-#endif
-  // All platforms.
-  path->assign(exe_buf);
-  return true;
-}
-
-}  // namespace deno
diff --git a/core/libdeno/file_util.h b/core/libdeno/file_util.h
deleted file mode 100644
index 0177f2c94..000000000
--- a/core/libdeno/file_util.h
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-#ifndef FILE_UTIL_H_
-#define FILE_UTIL_H_
-
-#include <string>
-
-namespace deno {
-bool ReadFileToString(const char* fn, std::string* contents);
-std::string Basename(std::string const& filename);
-std::string Dirname(std::string const& filename);
-bool ExePath(std::string* path);
-}  // namespace deno
-
-#endif  // FILE_UTIL_H_
diff --git a/core/libdeno/file_util_test.cc b/core/libdeno/file_util_test.cc
deleted file mode 100644
index 863a31d48..000000000
--- a/core/libdeno/file_util_test.cc
+++ /dev/null
@@ -1,46 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-#include "testing/gtest/include/gtest/gtest.h"
-
-#include "file_util.h"
-
-TEST(FileUtilTest, ReadFileToStringFileNotExist) {
-  std::string output;
-  EXPECT_FALSE(deno::ReadFileToString("/should_error_out.txt", &output));
-}
-
-TEST(FileUtilTest, Basename) {
-  EXPECT_EQ("foo.txt", deno::Basename("foo.txt"));
-  EXPECT_EQ("foo.txt", deno::Basename("/foo.txt"));
-  EXPECT_EQ("", deno::Basename("/foo/"));
-  EXPECT_EQ("", deno::Basename("foo/"));
-  EXPECT_EQ("", deno::Basename("/"));
-  EXPECT_EQ("foo.txt", deno::Basename(".\\foo.txt"));
-  EXPECT_EQ("foo.txt", deno::Basename("/home/ryan/foo.txt"));
-  EXPECT_EQ("foo.txt", deno::Basename("C:\\home\\ryan\\foo.txt"));
-}
-
-TEST(FileUtilTest, Dirname) {
-  EXPECT_EQ("home/dank/", deno::Dirname("home/dank/memes.gif"));
-  EXPECT_EQ("/home/dank/", deno::Dirname("/home/dank/memes.gif"));
-  EXPECT_EQ("/home/dank/", deno::Dirname("/home/dank/"));
-  EXPECT_EQ("home/dank/", deno::Dirname("home/dank/memes.gif"));
-  EXPECT_EQ("/", deno::Dirname("/"));
-  EXPECT_EQ(".\\", deno::Dirname(".\\memes.gif"));
-  EXPECT_EQ("c:\\", deno::Dirname("c:\\stuff"));
-  EXPECT_EQ("./", deno::Dirname("nothing"));
-  EXPECT_EQ("./", deno::Dirname(""));
-}
-
-TEST(FileUtilTest, ExePath) {
-  std::string exe_path;
-  EXPECT_TRUE(deno::ExePath(&exe_path));
-  // Path is absolute.
-  EXPECT_TRUE(exe_path.find("/") == 0 || exe_path.find(":\\") == 1);
-  // FIlename is the name of the test binary.
-  std::string exe_filename = deno::Basename(exe_path);
-  EXPECT_EQ(exe_filename.find("libdeno_test"), 0u);
-  // Path exists (also tests ReadFileToString).
-  std::string contents;
-  EXPECT_TRUE(deno::ReadFileToString(exe_path.c_str(), &contents));
-  EXPECT_NE(contents.find("Inception :)"), std::string::npos);
-}
diff --git a/core/libdeno/snapshot_creator.cc b/core/libdeno/snapshot_creator.cc
deleted file mode 100644
index bd3c8081d..000000000
--- a/core/libdeno/snapshot_creator.cc
+++ /dev/null
@@ -1,46 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-// Hint: --trace_serializer is a useful debugging flag.
-#include <fstream>
-#include <iostream>
-#include "deno.h"
-#include "file_util.h"
-#include "internal.h"
-#include "third_party/v8/include/v8.h"
-#include "third_party/v8/src/base/logging.h"
-
-int main(int argc, char** argv) {
-  const char* snapshot_out_bin = argv[1];
-  const char* js_fn = argv[2];
-
-  deno_set_v8_flags(&argc, argv);
-
-  CHECK_NOT_NULL(js_fn);
-  CHECK_NOT_NULL(snapshot_out_bin);
-
-  std::string js_source;
-  CHECK(deno::ReadFileToString(js_fn, &js_source));
-
-  deno_init();
-  deno_config config = {1, deno::empty_snapshot, deno::empty_buf, nullptr,
-                        nullptr};
-  Deno* d = deno_new(config);
-
-  deno_execute(d, nullptr, js_fn, js_source.c_str());
-  if (deno_last_exception(d) != nullptr) {
-    std::cerr << "Snapshot Exception " << std::endl;
-    std::cerr << deno_last_exception(d) << std::endl;
-    deno_delete(d);
-    return 1;
-  }
-
-  auto snapshot = deno_snapshot_new(d);
-
-  std::ofstream file_(snapshot_out_bin, std::ios::binary);
-  file_.write(reinterpret_cast<char*>(snapshot.data_ptr), snapshot.data_len);
-  file_.close();
-
-  deno_snapshot_delete(snapshot);
-  deno_delete(d);
-
-  return file_.bad();
-}
diff --git a/core/libdeno/test.cc b/core/libdeno/test.cc
index 3d022c904..0bfe374ef 100644
--- a/core/libdeno/test.cc
+++ b/core/libdeno/test.cc
@@ -1,28 +1,44 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 #include "test.h"
+#include <fstream>
 #include <string>
-#include "file_util.h"
+#include "internal.h"
 
 deno_snapshot snapshot = {nullptr, 0};
 
-int main(int argc, char** argv) {
-  // Locate the snapshot.
-  std::string exe_path;
-  if (!deno::ExePath(&exe_path)) {
-    std::cerr << "deno::ExePath() failed" << std::endl;
-    return 1;
+bool ReadFileToString(const char* fn, std::string* contents) {
+  std::ifstream file(fn, std::ios::binary);
+  if (file.fail()) {
+    return false;
   }
-  std::string snapshot_path = deno::Dirname(exe_path) + SNAPSHOT_PATH;
+  contents->assign(std::istreambuf_iterator<char>{file}, {});
+  return !file.fail();
+}
+
+int main(int argc, char** argv) {
+  // All of the JS code in libdeno_test.js is tested after being snapshotted.
+  // We create that snapshot now at runtime, rather than at compile time to
+  // simplify the build process. So we load and execute the libdeno_test.js
+  // file, without running any of the tests and store the result in the global
+  // "snapshot" variable, which will be used later in the tests.
+  std::string js_fn = JS_PATH;
+  std::string js_source;
+  CHECK(ReadFileToString(js_fn.c_str(), &js_source));
+
+  deno_init();
+  deno_config config = {1, deno::empty_snapshot, deno::empty_buf, nullptr,
+                        nullptr};
+  Deno* d = deno_new(config);
 
-  // Load the snapshot.
-  std::string contents;
-  if (!deno::ReadFileToString(snapshot_path.c_str(), &contents)) {
-    std::cerr << "Failed to read snapshot from " << snapshot_path << std::endl;
+  deno_execute(d, nullptr, js_fn.c_str(), js_source.c_str());
+  if (deno_last_exception(d) != nullptr) {
+    std::cerr << "Snapshot Exception " << std::endl;
+    std::cerr << deno_last_exception(d) << std::endl;
+    deno_delete(d);
     return 1;
   }
-  snapshot.data_ptr =
-      reinterpret_cast<uint8_t*>(const_cast<char*>(contents.c_str()));
-  snapshot.data_len = contents.size();
+
+  snapshot = deno_snapshot_new(d);
 
   testing::InitGoogleTest(&argc, argv);
   deno_init();
diff --git a/core/snapshot_creator.rs b/core/snapshot_creator.rs
new file mode 100644
index 000000000..1d43b9174
--- /dev/null
+++ b/core/snapshot_creator.rs
@@ -0,0 +1,44 @@
+// Note: This is a nearly identical rewrite of core/libdeno/snapshot_creator.cc
+// but in Rust.
+//
+// This snapshot program is considered "basic" because the code being
+// snapshotted cannot call ops.
+
+extern crate deno;
+
+use deno::js_check;
+use deno::Isolate;
+use deno::StartupData;
+use std::env;
+use std::io::Write;
+
+fn main() {
+  let args: Vec<String> = env::args().collect();
+  // NOTE: `--help` arg will display V8 help and exit
+  let args = deno::v8_set_flags(args);
+
+  let (snapshot_out_bin, js_filename) = if args.len() == 3 {
+    (args[1].clone(), args[2].clone())
+  } else {
+    eprintln!("Usage: snapshot_creator <out_filename> <js_filename>");
+    std::process::exit(1);
+  };
+
+  let js_source =
+    std::fs::read(&js_filename).expect("couldn't read js_filename");
+  let js_source_str = std::str::from_utf8(&js_source).unwrap();
+
+  let will_snapshot = true;
+  let mut isolate = Isolate::new(StartupData::None, will_snapshot);
+
+  js_check(isolate.execute(&js_filename, js_source_str));
+
+  let snapshot = isolate.snapshot().expect("error snapshotting");
+
+  let mut out_file = std::fs::File::create(snapshot_out_bin).unwrap();
+  let snapshot_slice =
+    unsafe { std::slice::from_raw_parts(snapshot.data_ptr, snapshot.data_len) };
+  out_file
+    .write_all(snapshot_slice)
+    .expect("Failed to write snapshot file");
+}