1 files changed, 81 insertions, 0 deletions
diff --git a/runtime/build.rs b/runtime/build.rs
new file mode 100644
index 000000000..7c74c9793
--- /dev/null
+++ b/runtime/build.rs
@@ -0,0 +1,81 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+use deno_core::JsRuntime;
+use deno_core::RuntimeOptions;
+use std::env;
+use std::path::Path;
+use std::path::PathBuf;
+
+// TODO(bartlomieju): this module contains a lot of duplicated
+// logic with `cli/build.rs`, factor out to `deno_core`.
+fn create_snapshot(
+  mut js_runtime: JsRuntime,
+  snapshot_path: &Path,
+  files: Vec<PathBuf>,
+) {
+  deno_web::init(&mut js_runtime);
+  deno_fetch::init(&mut js_runtime);
+  deno_crypto::init(&mut js_runtime);
+  // TODO(nayeemrmn): https://github.com/rust-lang/cargo/issues/3946 to get the
+  // workspace root.
+  let display_root = Path::new(env!("CARGO_MANIFEST_DIR")).parent().unwrap();
+  for file in files {
+    println!("cargo:rerun-if-changed={}", file.display());
+    let display_path = file.strip_prefix(display_root).unwrap();
+    let display_path_str = display_path.display().to_string();
+    js_runtime
+      .execute(
+        &("deno:".to_string() + &display_path_str.replace('\\', "/")),
+        &std::fs::read_to_string(&file).unwrap(),
+      )
+      .unwrap();
+  }
+
+  let snapshot = js_runtime.snapshot();
+  let snapshot_slice: &[u8] = &*snapshot;
+  println!("Snapshot size: {}", snapshot_slice.len());
+  std::fs::write(&snapshot_path, snapshot_slice).unwrap();
+  println!("Snapshot written to: {} ", snapshot_path.display());
+}
+
+fn create_runtime_snapshot(snapshot_path: &Path, files: Vec<PathBuf>) {
+  let js_runtime = JsRuntime::new(RuntimeOptions {
+    will_snapshot: true,
+    ..Default::default()
+  });
+  create_snapshot(js_runtime, snapshot_path, files);
+}
+
+fn main() {
+  // Don't build V8 if "cargo doc" is being run. This is to support docs.rs.
+  if env::var_os("RUSTDOCFLAGS").is_some() {
+    return;
+  }
+
+  // To debug snapshot issues uncomment:
+  // op_fetch_asset::trace_serializer();
+
+  println!("cargo:rustc-env=TARGET={}", env::var("TARGET").unwrap());
+  println!("cargo:rustc-env=PROFILE={}", env::var("PROFILE").unwrap());
+  let o = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+
+  // Main snapshot
+  let runtime_snapshot_path = o.join("CLI_SNAPSHOT.bin");
+
+  let js_files = get_js_files("rt");
+  create_runtime_snapshot(&runtime_snapshot_path, js_files);
+}
+
+fn get_js_files(d: &str) -> Vec<PathBuf> {
+  let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
+  let mut js_files = std::fs::read_dir(d)
+    .unwrap()
+    .map(|dir_entry| {
+      let file = dir_entry.unwrap();
+      manifest_dir.join(file.path())
+    })
+    .filter(|path| path.extension().unwrap_or_default() == "js")
+    .collect::<Vec<PathBuf>>();
+  js_files.sort();
+  js_files
+}