feat: denort binary (#9041)

This commit adds new binary target called "denort".

It is a "lite" version of "deno" binary that can only execute
code embedded inside the binary itself.

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

18 files changed, 300 insertions, 257 deletions

diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 99760023a..bea5e87a5 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -14,6 +14,11 @@ default-run = "deno"
 name = "deno"
 path = "main.rs"
 
+[[bin]]
+name = "denort"
+path = "main_runtime.rs"
+
+
 [[bench]]
 name = "deno_bench"
 harness = false
@@ -51,7 +56,7 @@ indexmap = "1.6.0"
 jsonc-parser = "0.14.0"
 lazy_static = "1.4.0"
 libc = "0.2.77"
-log = "0.4.11"
+log = { version = "0.4.11", features = ["serde"] }
 lspower = "0.1.0"
 notify = "5.0.0-pre.3"
 percent-encoding = "2.1.0"
diff --git a/cli/bench/main.rs b/cli/bench/main.rs
index ea693fb3a..d796237d1 100644
--- a/cli/bench/main.rs
+++ b/cli/bench/main.rs
@@ -202,6 +202,12 @@ fn get_binary_sizes(target_dir: &PathBuf) -> Result<Value> {
     Value::Number(Number::from(test_util::deno_exe_path().metadata()?.len())),
   );
 
+  // add up size for denort
+  sizes.insert(
+    "denort".to_string(),
+    Value::Number(Number::from(test_util::denort_exe_path().metadata()?.len())),
+  );
+
   // add up size for everything in target/release/deps/libswc*
   let swc_size = rlib_size(&target_dir, "libswc");
   println!("swc {} bytes", swc_size);
diff --git a/cli/colors.rs b/cli/colors.rs
index 93f252716..97813a72c 100644
--- a/cli/colors.rs
+++ b/cli/colors.rs
@@ -1,5 +1,8 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
+// allow(dead_code) because denort does not use this.
+#![allow(dead_code)]
+
 use regex::Regex;
 use std::env;
 use std::fmt;
diff --git a/cli/file_fetcher.rs b/cli/file_fetcher.rs
index 5a31ee6cc..632b713a0 100644
--- a/cli/file_fetcher.rs
+++ b/cli/file_fetcher.rs
@@ -4,10 +4,10 @@ use crate::colors;
 use crate::http_cache::HttpCache;
 use crate::http_util::create_http_client;
 use crate::http_util::fetch_once;
-use crate::http_util::get_user_agent;
 use crate::http_util::FetchOnceResult;
 use crate::media_type::MediaType;
 use crate::text_encoding;
+use crate::version::get_user_agent;
 use deno_runtime::permissions::Permissions;
 
 use deno_core::error::custom_error;
diff --git a/cli/flags.rs b/cli/flags.rs
index 6b4e5aa5f..7e48c8428 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -6,15 +6,11 @@ use clap::Arg;
 use clap::ArgMatches;
 use clap::ArgSettings;
 use clap::SubCommand;
-use deno_core::serde::de;
 use deno_core::serde::Deserialize;
-use deno_core::serde::Deserializer;
 use deno_core::serde::Serialize;
-use deno_core::serde::Serializer;
 use deno_core::url::Url;
 use deno_runtime::permissions::PermissionsOptions;
 use log::Level;
-use std::fmt;
 use std::net::SocketAddr;
 use std::path::PathBuf;
 use std::str::FromStr;
@@ -100,66 +96,7 @@ impl Default for DenoSubcommand {
   }
 }
 
-fn deserialize_maybe_log_level<'de, D>(d: D) -> Result<Option<Level>, D::Error>
-where
-  D: Deserializer<'de>,
-{
-  struct OptionalLogLevelVisitor;
-  impl<'de> de::Visitor<'de> for OptionalLogLevelVisitor {
-    type Value = Option<Level>;
-
-    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-      write!(formatter, "null or a valid log level string")
-    }
-
-    fn visit_none<E>(self) -> Result<Self::Value, E>
-    where
-      E: de::Error,
-    {
-      Ok(None)
-    }
-
-    fn visit_some<D>(self, d: D) -> Result<Self::Value, D::Error>
-    where
-      D: de::Deserializer<'de>,
-    {
-      struct LogLevelVisitor;
-      impl<'de> de::Visitor<'de> for LogLevelVisitor {
-        type Value = Level;
-
-        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-          write!(formatter, "a valid log level string")
-        }
-
-        fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-        where
-          E: de::Error,
-        {
-          Level::from_str(s).map_err(|_| {
-            de::Error::invalid_value(de::Unexpected::Str(s), &self)
-          })
-        }
-      }
-      Ok(Some(d.deserialize_str(LogLevelVisitor)?))
-    }
-  }
-  d.deserialize_option(OptionalLogLevelVisitor)
-}
-
-fn serialize_maybe_log_level<S>(
-  maybe_level: &Option<Level>,
-  s: S,
-) -> Result<S::Ok, S::Error>
-where
-  S: Serializer,
-{
-  match maybe_level {
-    None => s.serialize_none(),
-    Some(level) => s.serialize_str(&level.to_string()),
-  }
-}
-
-#[derive(Clone, Debug, PartialEq, Default, Deserialize, Serialize)]
+#[derive(Clone, Debug, PartialEq, Default)]
 pub struct Flags {
   /// Vector of CLI arguments - these are user script arguments, all Deno
   /// specific flags are removed.
@@ -185,8 +122,6 @@ pub struct Flags {
   pub inspect_brk: Option<SocketAddr>,
   pub lock: Option<PathBuf>,
   pub lock_write: bool,
-  #[serde(deserialize_with = "deserialize_maybe_log_level")]
-  #[serde(serialize_with = "serialize_maybe_log_level")]
   pub log_level: Option<Level>,
   pub no_check: bool,
   pub no_prompts: bool,
diff --git a/cli/http_util.rs b/cli/http_util.rs
index df2a7d3a2..a27928055 100644
--- a/cli/http_util.rs
+++ b/cli/http_util.rs
@@ -1,6 +1,5 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
-use crate::version;
 use deno_core::error::generic_error;
 use deno_core::error::AnyError;
 use deno_core::url::Url;
@@ -15,10 +14,6 @@ use deno_runtime::deno_fetch::reqwest::Client;
 use deno_runtime::deno_fetch::reqwest::StatusCode;
 use std::collections::HashMap;
 
-pub fn get_user_agent() -> String {
-  format!("Deno/{}", version::deno())
-}
-
 /// Create new instance of async reqwest::Client. This client supports
 /// proxies and doesn't follow redirects.
 pub fn create_http_client(
@@ -155,6 +150,7 @@ pub async fn fetch_once(
 #[cfg(test)]
 mod tests {
   use super::*;
+  use crate::version;
   use std::fs::read;
 
   fn create_test_client(ca_data: Option<Vec<u8>>) -> Client {
@@ -313,7 +309,7 @@ mod tests {
       Url::parse("https://localhost:5545/cli/tests/fixture.json").unwrap();
 
     let client = create_http_client(
-      get_user_agent(),
+      version::get_user_agent(),
       Some(
         read(
           test_util::root_path()
@@ -345,7 +341,7 @@ mod tests {
     )
     .unwrap();
     let client = create_http_client(
-      get_user_agent(),
+      version::get_user_agent(),
       Some(
         read(
           test_util::root_path()
@@ -376,7 +372,7 @@ mod tests {
     let _http_server_guard = test_util::http_server();
     let url = Url::parse("https://localhost:5545/etag_script.ts").unwrap();
     let client = create_http_client(
-      get_user_agent(),
+      version::get_user_agent(),
       Some(
         read(
           test_util::root_path()
@@ -416,7 +412,7 @@ mod tests {
     )
     .unwrap();
     let client = create_http_client(
-      get_user_agent(),
+      version::get_user_agent(),
       Some(
         read(
           test_util::root_path()
diff --git a/cli/info.rs b/cli/info.rs
index d2ea4e7e6..ededcc024 100644
--- a/cli/info.rs
+++ b/cli/info.rs
@@ -2,8 +2,8 @@
 
 use crate::colors;
 use crate::media_type::serialize_media_type;
-use crate::MediaType;
-use crate::ModuleSpecifier;
+use crate::media_type::MediaType;
+use deno_core::ModuleSpecifier;
 
 use serde::Serialize;
 use serde::Serializer;
diff --git a/cli/lsp/sources.rs b/cli/lsp/sources.rs
index 5ef16a876..7d1fd56f3 100644
--- a/cli/lsp/sources.rs
+++ b/cli/lsp/sources.rs
@@ -14,7 +14,7 @@ use crate::module_graph::GraphBuilder;
 use crate::program_state::ProgramState;
 use crate::specifier_handler::FetchHandler;
 use crate::text_encoding;
-use crate::Permissions;
+use deno_runtime::permissions::Permissions;
 
 use deno_core::error::AnyError;
 use deno_core::serde_json;
diff --git a/cli/main.rs b/cli/main.rs
index 066991624..a3b8f3a6d 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -55,7 +55,6 @@ use crate::program_state::exit_unstable;
 use crate::program_state::ProgramState;
 use crate::source_maps::apply_source_map;
 use crate::specifier_handler::FetchHandler;
-use crate::standalone::create_standalone_binary;
 use crate::tools::installer::infer_name_from_url;
 use deno_core::error::generic_error;
 use deno_core::error::AnyError;
@@ -116,7 +115,7 @@ fn create_web_worker_callback(
         .map_or(false, |l| l == log::Level::Debug),
       unstable: program_state.flags.unstable,
       ca_data: program_state.ca_data.clone(),
-      user_agent: http_util::get_user_agent(),
+      user_agent: version::get_user_agent(),
       seed: program_state.flags.seed,
       module_loader,
       create_web_worker_cb,
@@ -192,7 +191,7 @@ pub fn create_main_worker(
       .map_or(false, |l| l == log::Level::Debug),
     unstable: program_state.flags.unstable,
     ca_data: program_state.ca_data.clone(),
-    user_agent: http_util::get_user_agent(),
+    user_agent: version::get_user_agent(),
     seed: program_state.flags.seed,
     js_error_create_fn: Some(js_error_create_fn),
     create_web_worker_cb,
@@ -307,7 +306,8 @@ async fn compile_command(
 
   let debug = flags.log_level == Some(log::Level::Debug);
 
-  let run_flags = standalone::compile_to_runtime_flags(flags.clone(), args)?;
+  let run_flags =
+    tools::standalone::compile_to_runtime_flags(flags.clone(), args)?;
 
   let module_specifier = ModuleSpecifier::resolve_url_or_path(&source_file)?;
   let program_state = ProgramState::new(flags.clone())?;
@@ -337,7 +337,12 @@ async fn compile_command(
     colors::green("Compile"),
     module_specifier.to_string()
   );
-  create_standalone_binary(bundle_str, run_flags, output.clone()).await?;
+  tools::standalone::create_standalone_binary(
+    bundle_str,
+    run_flags,
+    output.clone(),
+  )
+  .await?;
 
   info!("{} {}", colors::green("Emit"), output.display());
 
@@ -1244,7 +1249,14 @@ pub fn main() {
   colors::enable_ansi(); // For Windows 10
 
   let args: Vec<String> = env::args().collect();
-  if let Err(err) = standalone::try_run_standalone_binary(args.clone()) {
+  let standalone_res = match standalone::extract_standalone(args.clone()) {
+    Ok(Some((metadata, bundle))) => {
+      tokio_util::run_basic(standalone::run(bundle, metadata))
+    }
+    Ok(None) => Ok(()),
+    Err(err) => Err(err),
+  };
+  if let Err(err) = standalone_res {
     eprintln!("{}: {}", colors::red_bold("error"), err.to_string());
     std::process::exit(1);
   }
diff --git a/cli/main_runtime.rs b/cli/main_runtime.rs
new file mode 100644
index 000000000..12cb4329d
--- /dev/null
+++ b/cli/main_runtime.rs
@@ -0,0 +1,32 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+#![deny(warnings)]
+
+#[macro_use]
+extern crate lazy_static;
+
+mod colors;
+mod standalone;
+mod tokio_util;
+mod version;
+
+use deno_core::error::anyhow;
+use deno_core::error::AnyError;
+use std::env;
+
+pub fn main() {
+  #[cfg(windows)]
+  colors::enable_ansi(); // For Windows 10
+
+  let args: Vec<String> = env::args().collect();
+  if let Err(err) = run(args) {
+    eprintln!("{}: {}", colors::red_bold("error"), err.to_string());
+    std::process::exit(1);
+  }
+}
+
+fn run(args: Vec<String>) -> Result<(), AnyError> {
+  let (metadata, bundle) = standalone::extract_standalone(args)?
+    .ok_or_else(|| anyhow!("This executable is used internally by 'deno compile', it is not meant to be invoked directly."))?;
+  tokio_util::run_basic(standalone::run(bundle, metadata))
+}
diff --git a/cli/module_graph.rs b/cli/module_graph.rs
index 686c1bd0e..f2e693724 100644
--- a/cli/module_graph.rs
+++ b/cli/module_graph.rs
@@ -25,7 +25,7 @@ use crate::tsc;
 use crate::tsc_config::IgnoredCompilerOptions;
 use crate::tsc_config::TsConfig;
 use crate::version;
-use crate::AnyError;
+use deno_core::error::AnyError;
 
 use deno_core::error::anyhow;
 use deno_core::error::custom_error;
diff --git a/cli/program_state.rs b/cli/program_state.rs
index 896f4d7b4..ad44d8e9b 100644
--- a/cli/program_state.rs
+++ b/cli/program_state.rs
@@ -5,7 +5,6 @@ use crate::file_fetcher::CacheSetting;
 use crate::file_fetcher::FileFetcher;
 use crate::flags;
 use crate::http_cache;
-use crate::http_util;
 use crate::import_map::ImportMap;
 use crate::lockfile::Lockfile;
 use crate::module_graph::CheckOptions;
@@ -14,6 +13,7 @@ use crate::module_graph::TranspileOptions;
 use crate::module_graph::TypeLib;
 use crate::source_maps::SourceMapGetter;
 use crate::specifier_handler::FetchHandler;
+use crate::version;
 use deno_runtime::inspector::InspectorServer;
 use deno_runtime::permissions::Permissions;
 
@@ -106,7 +106,7 @@ impl ProgramState {
     let maybe_inspector_server = match maybe_inspect_host {
       Some(host) => Some(Arc::new(InspectorServer::new(
         host,
-        http_util::get_user_agent(),
+        version::get_user_agent(),
       ))),
       None => None,
     };
diff --git a/cli/standalone.rs b/cli/standalone.rs
index 8d95d30f2..a4b55f081 100644
--- a/cli/standalone.rs
+++ b/cli/standalone.rs
@@ -1,9 +1,7 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
 use crate::colors;
-use crate::flags::DenoSubcommand;
-use crate::flags::Flags;
-use crate::tokio_util;
 use crate::version;
-use deno_core::error::bail;
 use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::error::Context;
@@ -11,35 +9,41 @@ use deno_core::futures::FutureExt;
 use deno_core::serde::Deserialize;
 use deno_core::serde::Serialize;
 use deno_core::serde_json;
+use deno_core::url::Url;
 use deno_core::v8_set_flags;
 use deno_core::ModuleLoader;
 use deno_core::ModuleSpecifier;
 use deno_core::OpState;
 use deno_runtime::permissions::Permissions;
+use deno_runtime::permissions::PermissionsOptions;
 use deno_runtime::worker::MainWorker;
 use deno_runtime::worker::WorkerOptions;
+use log::Level;
 use std::cell::RefCell;
 use std::convert::TryInto;
 use std::env::current_exe;
-use std::fs::read;
 use std::fs::File;
 use std::io::Read;
 use std::io::Seek;
 use std::io::SeekFrom;
-use std::io::Write;
 use std::iter::once;
-use std::path::PathBuf;
 use std::pin::Pin;
 use std::rc::Rc;
 use std::sync::Arc;
 
 #[derive(Deserialize, Serialize)]
-struct Metadata {
-  flags: Flags,
-  ca_data: Option<Vec<u8>>,
+pub struct Metadata {
+  pub argv: Vec<String>,
+  pub unstable: bool,
+  pub seed: Option<u64>,
+  pub permissions: PermissionsOptions,
+  pub location: Option<Url>,
+  pub v8_flags: Vec<String>,
+  pub log_level: Option<Level>,
+  pub ca_data: Option<Vec<u8>>,
 }
 
-const MAGIC_TRAILER: &[u8; 8] = b"d3n0l4nd";
+pub const MAGIC_TRAILER: &[u8; 8] = b"d3n0l4nd";
 
 /// This function will try to run this binary as a standalone binary
 /// produced by `deno compile`. It determines if this is a stanalone
@@ -50,7 +54,9 @@ const MAGIC_TRAILER: &[u8; 8] = b"d3n0l4nd";
 /// These are dereferenced, and the bundle is executed under the configuration
 /// specified by the metadata. If no magic trailer is present, this function
 /// exits with `Ok(())`.
-pub fn try_run_standalone_binary(args: Vec<String>) -> Result<(), AnyError> {
+pub fn extract_standalone(
+  args: Vec<String>,
+) -> Result<Option<(Metadata, String)>, AnyError> {
   let current_exe_path = current_exe()?;
 
   let mut current_exe = File::open(current_exe_path)?;
@@ -58,31 +64,27 @@ pub fn try_run_standalone_binary(args: Vec<String>) -> Result<(), AnyError> {
   let mut trailer = [0; 24];
   current_exe.read_exact(&mut trailer)?;
   let (magic_trailer, rest) = trailer.split_at(8);
-  if magic_trailer == MAGIC_TRAILER {
-    let (bundle_pos, rest) = rest.split_at(8);
-    let metadata_pos = rest;
-    let bundle_pos = u64_from_bytes(bundle_pos)?;
-    let metadata_pos = u64_from_bytes(metadata_pos)?;
-    let bundle_len = metadata_pos - bundle_pos;
-    let metadata_len = trailer_pos - metadata_pos;
-    current_exe.seek(SeekFrom::Start(bundle_pos))?;
-
-    let bundle = read_string_slice(&mut current_exe, bundle_pos, bundle_len)
-      .context("Failed to read source bundle from the current executable")?;
-    let metadata =
-      read_string_slice(&mut current_exe, metadata_pos, metadata_len)
-        .context("Failed to read metadata from the current executable")?;
-
-    let mut metadata: Metadata = serde_json::from_str(&metadata).unwrap();
-    metadata.flags.argv.append(&mut args[1..].to_vec());
-    if let Err(err) = tokio_util::run_basic(run(bundle, metadata)) {
-      eprintln!("{}: {}", colors::red_bold("error"), err.to_string());
-      std::process::exit(1);
-    }
-    std::process::exit(0);
-  } else {
-    Ok(())
+  if magic_trailer != MAGIC_TRAILER {
+    return Ok(None);
   }
+
+  let (bundle_pos, rest) = rest.split_at(8);
+  let metadata_pos = rest;
+  let bundle_pos = u64_from_bytes(bundle_pos)?;
+  let metadata_pos = u64_from_bytes(metadata_pos)?;
+  let bundle_len = metadata_pos - bundle_pos;
+  let metadata_len = trailer_pos - metadata_pos;
+  current_exe.seek(SeekFrom::Start(bundle_pos))?;
+
+  let bundle = read_string_slice(&mut current_exe, bundle_pos, bundle_len)
+    .context("Failed to read source bundle from the current executable")?;
+  let metadata =
+    read_string_slice(&mut current_exe, metadata_pos, metadata_len)
+      .context("Failed to read metadata from the current executable")?;
+
+  let mut metadata: Metadata = serde_json::from_str(&metadata).unwrap();
+  metadata.argv.append(&mut args[1..].to_vec());
+  Ok(Some((metadata, bundle)))
 }
 
 fn u64_from_bytes(arr: &[u8]) -> Result<u64, AnyError> {
@@ -149,10 +151,12 @@ impl ModuleLoader for EmbeddedModuleLoader {
   }
 }
 
-async fn run(source_code: String, metadata: Metadata) -> Result<(), AnyError> {
-  let Metadata { flags, ca_data } = metadata;
+pub async fn run(
+  source_code: String,
+  metadata: Metadata,
+) -> Result<(), AnyError> {
   let main_module = ModuleSpecifier::resolve_url(SPECIFIER)?;
-  let permissions = Permissions::from_options(&flags.clone().into());
+  let permissions = Permissions::from_options(&metadata.permissions);
   let module_loader = Rc::new(EmbeddedModuleLoader(source_code));
   let create_web_worker_cb = Arc::new(|_| {
     todo!("Worker are currently not supported in standalone binaries");
@@ -161,18 +165,18 @@ async fn run(source_code: String, metadata: Metadata) -> Result<(), AnyError> {
   // Keep in sync with `main.rs`.
   v8_set_flags(
     once("UNUSED_BUT_NECESSARY_ARG0".to_owned())
-      .chain(flags.v8_flags.iter().cloned())
+      .chain(metadata.v8_flags.iter().cloned())
       .collect::<Vec<_>>(),
   );
-  // TODO(nayeemrmn): Unify this Flags -> WorkerOptions mapping with `deno run`.
+
   let options = WorkerOptions {
     apply_source_maps: false,
-    args: flags.argv,
-    debug_flag: flags.log_level.map_or(false, |l| l == log::Level::Debug),
-    user_agent: crate::http_util::get_user_agent(),
-    unstable: flags.unstable,
-    ca_data,
-    seed: flags.seed,
+    args: metadata.argv,
+    debug_flag: metadata.log_level.map_or(false, |l| l == log::Level::Debug),
+    user_agent: version::get_user_agent(),
+    unstable: metadata.unstable,
+    ca_data: metadata.ca_data,
+    seed: metadata.seed,
     js_error_create_fn: None,
     create_web_worker_cb,
     attach_inspector: false,
@@ -182,8 +186,8 @@ async fn run(source_code: String, metadata: Metadata) -> Result<(), AnyError> {
     runtime_version: version::deno(),
     ts_version: version::TYPESCRIPT.to_string(),
     no_color: !colors::use_color(),
-    get_error_class_fn: Some(&crate::errors::get_error_class_name),
-    location: flags.location,
+    get_error_class_fn: Some(&get_error_class_name),
+    location: metadata.location,
   };
   let mut worker =
     MainWorker::from_options(main_module.clone(), permissions, &options);
@@ -192,125 +196,11 @@ async fn run(source_code: String, metadata: Metadata) -> Result<(), AnyError> {
   worker.execute("window.dispatchEvent(new Event('load'))")?;
   worker.run_event_loop().await?;
   worker.execute("window.dispatchEvent(new Event('unload'))")?;
-  Ok(())
-}
-
-/// This functions creates a standalone deno binary by appending a bundle
-/// and magic trailer to the currently executing binary.
-pub async fn create_standalone_binary(
-  source_code: String,
-  flags: Flags,
-  output: PathBuf,
-) -> Result<(), AnyError> {
-  let mut source_code = source_code.as_bytes().to_vec();
-  let ca_data = match &flags.ca_file {
-    Some(ca_file) => Some(read(ca_file)?),
-    None => None,
-  };
-  let metadata = Metadata { flags, ca_data };
-  let mut metadata = serde_json::to_string(&metadata)?.as_bytes().to_vec();
-  let original_binary_path = std::env::current_exe()?;
-  let mut original_bin = tokio::fs::read(original_binary_path).await?;
-
-  let bundle_pos = original_bin.len();
-  let metadata_pos = bundle_pos + source_code.len();
-  let mut trailer = MAGIC_TRAILER.to_vec();
-  trailer.write_all(&bundle_pos.to_be_bytes())?;
-  trailer.write_all(&metadata_pos.to_be_bytes())?;
-
-  let mut final_bin =
-    Vec::with_capacity(original_bin.len() + source_code.len() + trailer.len());
-  final_bin.append(&mut original_bin);
-  final_bin.append(&mut source_code);
-  final_bin.append(&mut metadata);
-  final_bin.append(&mut trailer);
-
-  let output =
-    if cfg!(windows) && output.extension().unwrap_or_default() != "exe" {
-      PathBuf::from(output.display().to_string() + ".exe")
-    } else {
-      output
-    };
-
-  if output.exists() {
-    // If the output is a directory, throw error
-    if output.is_dir() {
-      bail!("Could not compile: {:?} is a directory.", &output);
-    }
-
-    // Make sure we don't overwrite any file not created by Deno compiler.
-    // Check for magic trailer in last 24 bytes.
-    let mut has_trailer = false;
-    let mut output_file = File::open(&output)?;
-    // This seek may fail because the file is too small to possibly be
-    // `deno compile` output.
-    if output_file.seek(SeekFrom::End(-24)).is_ok() {
-      let mut trailer = [0; 24];
-      output_file.read_exact(&mut trailer)?;
-      let (magic_trailer, _) = trailer.split_at(8);
-      has_trailer = magic_trailer == MAGIC_TRAILER;
-    }
-    if !has_trailer {
-      bail!("Could not compile: cannot overwrite {:?}.", &output);
-    }
-  }
-  tokio::fs::write(&output, final_bin).await?;
-  #[cfg(unix)]
-  {
-    use std::os::unix::fs::PermissionsExt;
-    let perms = std::fs::Permissions::from_mode(0o777);
-    tokio::fs::set_permissions(output, perms).await?;
-  }
-
-  Ok(())
+  std::process::exit(0);
 }
 
-/// Transform the flags passed to `deno compile` to flags that would be used at
-/// runtime, as if `deno run` were used.
-/// - Flags that affect module resolution, loading, type checking, etc. aren't
-///   applicable at runtime so are set to their defaults like `false`.
-/// - Other flags are inherited.
-pub fn compile_to_runtime_flags(
-  flags: Flags,
-  baked_args: Vec<String>,
-) -> Result<Flags, AnyError> {
-  // IMPORTANT: Don't abbreviate any of this to `..flags` or
-  // `..Default::default()`. That forces us to explicitly consider how any
-  // change to `Flags` should be reflected here.
-  Ok(Flags {
-    argv: baked_args,
-    subcommand: DenoSubcommand::Run {
-      script: "placeholder".to_string(),
-    },
-    allow_env: flags.allow_env,
-    allow_hrtime: flags.allow_hrtime,
-    allow_net: flags.allow_net,
-    allow_plugin: flags.allow_plugin,
-    allow_read: flags.allow_read,
-    allow_run: flags.allow_run,
-    allow_write: flags.allow_write,
-    cache_blocklist: vec![],
-    ca_file: flags.ca_file,
-    cached_only: false,
-    config_path: None,
-    coverage_dir: flags.coverage_dir,
-    ignore: vec![],
-    import_map_path: None,
-    inspect: None,
-    inspect_brk: None,
-    location: flags.location,
-    lock: None,
-    lock_write: false,
-    log_level: flags.log_level,
-    no_check: false,
-    no_prompts: flags.no_prompts,
-    no_remote: false,
-    reload: false,
-    repl: false,
-    seed: flags.seed,
-    unstable: flags.unstable,
-    v8_flags: flags.v8_flags,
-    version: false,
-    watch: false,
+fn get_error_class_name(e: &AnyError) -> &'static str {
+  deno_runtime::errors::get_error_class_name(e).unwrap_or_else(|| {
+    panic!("Error '{}' contains boxed error of unknown type", e);
   })
 }
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index aabeb1f77..20e391171 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -5036,6 +5036,17 @@ fn standalone_runtime_flags() {
     .contains("PermissionDenied: write access"));
 }
 
+#[test]
+fn denort_direct_use_error() {
+  let status = Command::new(util::denort_exe_path())
+    .current_dir(util::root_path())
+    .spawn()
+    .unwrap()
+    .wait()
+    .unwrap();
+  assert!(!status.success());
+}
+
 fn concat_bundle(
   files: Vec<(PathBuf, String)>,
   bundle_path: &Path,
diff --git a/cli/tools/mod.rs b/cli/tools/mod.rs
index be76968fb..4489b7479 100644
--- a/cli/tools/mod.rs
+++ b/cli/tools/mod.rs
@@ -5,5 +5,6 @@ pub mod fmt;
 pub mod installer;
 pub mod lint;
 pub mod repl;
+pub mod standalone;
 pub mod test_runner;
 pub mod upgrade;
diff --git a/cli/tools/standalone.rs b/cli/tools/standalone.rs
new file mode 100644
index 000000000..112169756
--- /dev/null
+++ b/cli/tools/standalone.rs
@@ -0,0 +1,146 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+use crate::flags::DenoSubcommand;
+use crate::flags::Flags;
+use deno_core::error::bail;
+use deno_core::error::AnyError;
+use deno_core::serde_json;
+use std::fs::read;
+use std::fs::File;
+use std::io::Read;
+use std::io::Seek;
+use std::io::SeekFrom;
+use std::io::Write;
+use std::path::PathBuf;
+
+use crate::standalone::Metadata;
+use crate::standalone::MAGIC_TRAILER;
+
+/// This functions creates a standalone deno binary by appending a bundle
+/// and magic trailer to the currently executing binary.
+pub async fn create_standalone_binary(
+  source_code: String,
+  flags: Flags,
+  output: PathBuf,
+) -> Result<(), AnyError> {
+  let mut source_code = source_code.as_bytes().to_vec();
+  let ca_data = match &flags.ca_file {
+    Some(ca_file) => Some(read(ca_file)?),
+    None => None,
+  };
+  let metadata = Metadata {
+    argv: flags.argv.clone(),
+    unstable: flags.unstable,
+    seed: flags.seed,
+    location: flags.location.clone(),
+    permissions: flags.clone().into(),
+    v8_flags: flags.v8_flags.clone(),
+    log_level: flags.log_level,
+    ca_data,
+  };
+  let mut metadata = serde_json::to_string(&metadata)?.as_bytes().to_vec();
+  let original_binary_path = std::env::current_exe()?;
+  let mut original_bin = tokio::fs::read(original_binary_path).await?;
+
+  let bundle_pos = original_bin.len();
+  let metadata_pos = bundle_pos + source_code.len();
+  let mut trailer = MAGIC_TRAILER.to_vec();
+  trailer.write_all(&bundle_pos.to_be_bytes())?;
+  trailer.write_all(&metadata_pos.to_be_bytes())?;
+
+  let mut final_bin =
+    Vec::with_capacity(original_bin.len() + source_code.len() + trailer.len());
+  final_bin.append(&mut original_bin);
+  final_bin.append(&mut source_code);
+  final_bin.append(&mut metadata);
+  final_bin.append(&mut trailer);
+
+  let output =
+    if cfg!(windows) && output.extension().unwrap_or_default() != "exe" {
+      PathBuf::from(output.display().to_string() + ".exe")
+    } else {
+      output
+    };
+
+  if output.exists() {
+    // If the output is a directory, throw error
+    if output.is_dir() {
+      bail!("Could not compile: {:?} is a directory.", &output);
+    }
+
+    // Make sure we don't overwrite any file not created by Deno compiler.
+    // Check for magic trailer in last 24 bytes.
+    let mut has_trailer = false;
+    let mut output_file = File::open(&output)?;
+    // This seek may fail because the file is too small to possibly be
+    // `deno compile` output.
+    if output_file.seek(SeekFrom::End(-24)).is_ok() {
+      let mut trailer = [0; 24];
+      output_file.read_exact(&mut trailer)?;
+      let (magic_trailer, _) = trailer.split_at(8);
+      has_trailer = magic_trailer == MAGIC_TRAILER;
+    }
+    if !has_trailer {
+      bail!("Could not compile: cannot overwrite {:?}.", &output);
+    }
+  }
+  tokio::fs::write(&output, final_bin).await?;
+  #[cfg(unix)]
+  {
+    use std::os::unix::fs::PermissionsExt;
+    let perms = std::fs::Permissions::from_mode(0o777);
+    tokio::fs::set_permissions(output, perms).await?;
+  }
+
+  Ok(())
+}
+
+/// Transform the flags passed to `deno compile` to flags that would be used at
+/// runtime, as if `deno run` were used.
+/// - Flags that affect module resolution, loading, type checking, etc. aren't
+///   applicable at runtime so are set to their defaults like `false`.
+/// - Other flags are inherited.
+pub fn compile_to_runtime_flags(
+  flags: Flags,
+  baked_args: Vec<String>,
+) -> Result<Flags, AnyError> {
+  // IMPORTANT: Don't abbreviate any of this to `..flags` or
+  // `..Default::default()`. That forces us to explicitly consider how any
+  // change to `Flags` should be reflected here.
+  Ok(Flags {
+    argv: baked_args,
+    subcommand: DenoSubcommand::Run {
+      script: "placeholder".to_string(),
+    },
+    allow_env: flags.allow_env,
+    allow_hrtime: flags.allow_hrtime,
+    allow_net: flags.allow_net,
+    allow_plugin: flags.allow_plugin,
+    allow_read: flags.allow_read,
+    allow_run: flags.allow_run,
+    allow_write: flags.allow_write,
+    cache_blocklist: vec![],
+    ca_file: flags.ca_file,
+    cached_only: false,
+    config_path: None,
+    coverage_dir: flags.coverage_dir,
+    ignore: vec![],
+    import_map_path: None,
+    inspect: None,
+    inspect_brk: None,
+    location: flags.location,
+    lock: None,
+    lock_write: false,
+    log_level: flags.log_level,
+    no_check: false,
+    no_prompts: flags.no_prompts,
+    no_remote: false,
+    reload: false,
+    repl: false,
+    seed: flags.seed,
+    unstable: flags.unstable,
+    v8_flags: flags.v8_flags,
+    version: false,
+    watch: false,
+  })
+}
diff --git a/cli/tools/upgrade.rs b/cli/tools/upgrade.rs
index da26b3159..a404f75f5 100644
--- a/cli/tools/upgrade.rs
+++ b/cli/tools/upgrade.rs
@@ -2,7 +2,7 @@
 
 //! This module provides feature to upgrade deno executable
 
-use crate::AnyError;
+use deno_core::error::AnyError;
 use deno_runtime::deno_fetch::reqwest;
 use deno_runtime::deno_fetch::reqwest::Client;
 use semver_parser::version::parse as semver_parse;
diff --git a/cli/version.rs b/cli/version.rs
index 49cb34f1d..3c2f6a995 100644
--- a/cli/version.rs
+++ b/cli/version.rs
@@ -10,6 +10,12 @@ pub fn deno() -> String {
   })
 }
 
+// allow(dead_code) because denort does not use this.
+#[allow(dead_code)]
 pub fn is_canary() -> bool {
   option_env!("DENO_CANARY").is_some()
 }
+
+pub fn get_user_agent() -> String {
+  format!("Deno/{}", deno())
+}