Jakob Hellermann 79f96af262 add deno target
2020-06-01 16:07:19 +02:00

788 lines
25 KiB
Rust
Executable File

#![doc(html_root_url = "https://docs.rs/wasm-bindgen-cli-support/0.2")]
use anyhow::{bail, Context, Error};
use std::collections::{BTreeMap, HashMap, HashSet};
use std::env;
use std::fs;
use std::mem;
use std::path::{Path, PathBuf};
use std::str;
use walrus::Module;
pub(crate) const PLACEHOLDER_MODULE: &str = "__wbindgen_placeholder__";
mod decode;
mod descriptor;
mod descriptors;
mod externref;
mod intrinsic;
mod js;
mod multivalue;
mod throw2unreachable;
pub mod wasm2es6js;
mod wit;
pub struct Bindgen {
input: Input,
out_name: Option<String>,
mode: OutputMode,
debug: bool,
typescript: bool,
omit_imports: bool,
demangle: bool,
keep_debug: bool,
remove_name_section: bool,
remove_producers_section: bool,
emit_start: bool,
// Experimental support for weakrefs, an upcoming ECMAScript feature.
// Currently only enable-able through an env var.
weak_refs: bool,
// Support for the wasm threads proposal, transforms the wasm module to be
// "ready to be instantiated on any thread"
threads: wasm_bindgen_threads_xform::Config,
externref: bool,
multi_value: bool,
wasm_interface_types: bool,
encode_into: EncodeInto,
}
pub struct Output {
module: walrus::Module,
stem: String,
generated: Generated,
}
enum Generated {
InterfaceTypes,
Js(JsGenerated),
}
struct JsGenerated {
mode: OutputMode,
js: String,
ts: String,
start: Option<String>,
snippets: HashMap<String, Vec<String>>,
local_modules: HashMap<String, String>,
npm_dependencies: HashMap<String, (PathBuf, String)>,
typescript: bool,
}
#[derive(Clone)]
enum OutputMode {
Bundler { browser_only: bool },
Web,
NoModules { global: String },
Node { experimental_modules: bool },
Deno,
}
enum Input {
Path(PathBuf),
Module(Module, String),
None,
}
pub enum EncodeInto {
Test,
Always,
Never,
}
impl Bindgen {
pub fn new() -> Bindgen {
let externref =
env::var("WASM_BINDGEN_ANYREF").is_ok() || env::var("WASM_BINDGEN_EXTERNREF").is_ok();
let wasm_interface_types = env::var("WASM_INTERFACE_TYPES").is_ok();
let multi_value = env::var("WASM_BINDGEN_MULTI_VALUE").is_ok();
Bindgen {
input: Input::None,
out_name: None,
mode: OutputMode::Bundler {
browser_only: false,
},
debug: false,
typescript: false,
omit_imports: false,
demangle: true,
keep_debug: false,
remove_name_section: false,
remove_producers_section: false,
emit_start: true,
weak_refs: env::var("WASM_BINDGEN_WEAKREF").is_ok(),
threads: threads_config(),
externref: externref || wasm_interface_types,
multi_value: multi_value || wasm_interface_types,
wasm_interface_types,
encode_into: EncodeInto::Test,
}
}
pub fn input_path<P: AsRef<Path>>(&mut self, path: P) -> &mut Bindgen {
self.input = Input::Path(path.as_ref().to_path_buf());
self
}
pub fn out_name(&mut self, name: &str) -> &mut Bindgen {
self.out_name = Some(name.to_string());
self
}
/// Explicitly specify the already parsed input module.
pub fn input_module(&mut self, name: &str, module: Module) -> &mut Bindgen {
let name = name.to_string();
self.input = Input::Module(module, name);
return self;
}
fn switch_mode(&mut self, mode: OutputMode, flag: &str) -> Result<(), Error> {
match self.mode {
OutputMode::Bundler { .. } => self.mode = mode,
_ => bail!(
"cannot specify `{}` with another output mode already specified",
flag
),
}
Ok(())
}
pub fn nodejs(&mut self, node: bool) -> Result<&mut Bindgen, Error> {
if node {
self.switch_mode(
OutputMode::Node {
experimental_modules: false,
},
"--target nodejs",
)?;
}
Ok(self)
}
pub fn nodejs_experimental_modules(&mut self, node: bool) -> Result<&mut Bindgen, Error> {
if node {
self.switch_mode(
OutputMode::Node {
experimental_modules: true,
},
"--nodejs-experimental-modules",
)?;
}
Ok(self)
}
pub fn bundler(&mut self, bundler: bool) -> Result<&mut Bindgen, Error> {
if bundler {
self.switch_mode(
OutputMode::Bundler {
browser_only: false,
},
"--target bundler",
)?;
}
Ok(self)
}
pub fn web(&mut self, web: bool) -> Result<&mut Bindgen, Error> {
if web {
self.switch_mode(OutputMode::Web, "--target web")?;
}
Ok(self)
}
pub fn no_modules(&mut self, no_modules: bool) -> Result<&mut Bindgen, Error> {
if no_modules {
self.switch_mode(
OutputMode::NoModules {
global: "wasm_bindgen".to_string(),
},
"--target no-modules",
)?;
}
Ok(self)
}
pub fn browser(&mut self, browser: bool) -> Result<&mut Bindgen, Error> {
if browser {
match &mut self.mode {
OutputMode::Bundler { browser_only } => *browser_only = true,
_ => bail!("cannot specify `--browser` with other output types"),
}
}
Ok(self)
}
pub fn deno(&mut self, deno: bool) -> Result<&mut Bindgen, Error> {
if deno {
self.switch_mode(OutputMode::Deno, "--target deno")?;
self.encode_into(EncodeInto::Always);
}
Ok(self)
}
pub fn no_modules_global(&mut self, name: &str) -> Result<&mut Bindgen, Error> {
match &mut self.mode {
OutputMode::NoModules { global } => *global = name.to_string(),
_ => bail!("can only specify `--no-modules-global` with `--target no-modules`"),
}
Ok(self)
}
pub fn debug(&mut self, debug: bool) -> &mut Bindgen {
self.debug = debug;
self
}
pub fn typescript(&mut self, typescript: bool) -> &mut Bindgen {
self.typescript = typescript;
self
}
pub fn omit_imports(&mut self, omit_imports: bool) -> &mut Bindgen {
self.omit_imports = omit_imports;
self
}
pub fn demangle(&mut self, demangle: bool) -> &mut Bindgen {
self.demangle = demangle;
self
}
pub fn keep_debug(&mut self, keep_debug: bool) -> &mut Bindgen {
self.keep_debug = keep_debug;
self
}
pub fn remove_name_section(&mut self, remove: bool) -> &mut Bindgen {
self.remove_name_section = remove;
self
}
pub fn remove_producers_section(&mut self, remove: bool) -> &mut Bindgen {
self.remove_producers_section = remove;
self
}
pub fn emit_start(&mut self, emit: bool) -> &mut Bindgen {
self.emit_start = emit;
self
}
pub fn encode_into(&mut self, mode: EncodeInto) -> &mut Bindgen {
self.encode_into = mode;
self
}
pub fn generate<P: AsRef<Path>>(&mut self, path: P) -> Result<(), Error> {
self.generate_output()?.emit(path.as_ref())
}
pub fn generate_output(&mut self) -> Result<Output, Error> {
let (mut module, stem) = match self.input {
Input::None => bail!("must have an input by now"),
Input::Module(ref mut m, ref name) => {
let blank_module = Module::default();
(mem::replace(m, blank_module), &name[..])
}
Input::Path(ref path) => {
let wasm = wit_text::parse_file(&path)
.with_context(|| format!("failed to read `{}`", path.display()))?;
wit_validator::validate(&wasm)
.with_context(|| format!("failed to validate `{}`", path.display()))?;
let module = walrus::ModuleConfig::new()
// Skip validation of the module as LLVM's output is
// generally already well-formed and so we won't gain much
// from re-validating. Additionally LLVM's current output
// for threads includes atomic instructions but doesn't
// include shared memory, so it fails that part of
// validation!
.strict_validate(false)
.generate_dwarf(self.keep_debug)
.generate_name_section(!self.remove_name_section)
.generate_producers_section(!self.remove_producers_section)
.on_parse(wit_walrus::on_parse)
.parse(&wasm)
.context("failed to parse input file as wasm")?;
let stem = match &self.out_name {
Some(name) => &name,
None => path.file_stem().unwrap().to_str().unwrap(),
};
(module, stem)
}
};
// This isn't the hardest thing in the world too support but we
// basically don't know how to rationalize #[wasm_bindgen(start)] and
// the actual `start` function if present. Figure this out later if it
// comes up, but otherwise we should continue to be compatible with
// LLVM's output today.
//
// Note that start function handling in `js/mod.rs` will need to be
// updated as well, because `#[wasm_bindgen(start)]` is inserted *after*
// a module's start function, if any, because we assume start functions
// only show up when injected on behalf of wasm-bindgen's passes.
if module.start.is_some() {
bail!(
"wasm-bindgen is currently incompatible with modules that \
already have a start function"
);
}
self.threads
.run(&mut module)
.with_context(|| "failed to prepare module for threading")?;
// If requested, turn all mangled symbols into prettier unmangled
// symbols with the help of `rustc-demangle`.
if self.demangle {
demangle(&mut module);
}
unexported_unused_lld_things(&mut module);
// We're making quite a few changes, list ourselves as a producer.
module
.producers
.add_processed_by("wasm-bindgen", &wasm_bindgen_shared::version());
// Learn about the type signatures of all wasm-bindgen imports and
// exports by executing `__wbindgen_describe_*` functions. This'll
// effectively move all the descriptor functions to their own custom
// sections.
descriptors::execute(&mut module)?;
// Process and remove our raw custom sections emitted by the
// #[wasm_bindgen] macro and the compiler. In their stead insert a
// forward-compatible wasm interface types section as well as an
// auxiliary section for all sorts of miscellaneous information and
// features #[wasm_bindgen] supports that aren't covered by wasm
// interface types.
wit::process(
&mut module,
self.externref,
self.wasm_interface_types,
self.emit_start,
)?;
// Now that we've got type information from the webidl processing pass,
// touch up the output of rustc to insert externref shims where necessary.
// This is only done if the externref pass is enabled, which it's
// currently off-by-default since `externref` is still in development in
// engines.
//
// If the externref pass isn't necessary, then we blanket delete the
// export of all our externref intrinsics which will get cleaned up in the
// GC pass before JS generation.
if self.externref {
externref::process(&mut module)?;
} else {
let ids = module
.exports
.iter()
.filter(|e| e.name.starts_with("__externref"))
.map(|e| e.id())
.collect::<Vec<_>>();
for id in ids {
module.exports.delete(id);
}
// Clean up element segments as well if they have holes in them
// after some of our transformations, because non-externref engines
// only support contiguous arrays of function references in element
// segments.
externref::force_contiguous_elements(&mut module)?;
}
// If wasm interface types are enabled then the `__wbindgen_throw`
// intrinsic isn't available but it may be used by our runtime, so
// change all calls to this function to calls to `unreachable` instead.
// See more documentation in the pass documentation itself.
if self.wasm_interface_types {
throw2unreachable::run(&mut module);
}
// Using all of our metadata convert our module to a multi-value using
// module if applicable.
if self.multi_value {
if !self.wasm_interface_types {
anyhow::bail!(
"Wasm multi-value is currently only available when \
Wasm interface types is also enabled"
);
}
multivalue::run(&mut module)
.context("failed to transform return pointers into multi-value Wasm")?;
}
// We've done a whole bunch of transformations to the wasm module, many
// of which leave "garbage" lying around, so let's prune out all our
// unnecessary things here.
gc_module_and_adapters(&mut module);
// We're ready for the final emission passes now. If we're in wasm
// interface types mode then we execute the various passes there and
// generate a valid interface typess section into the wasm module.
//
// Otherwise we execute the JS generation passes to actually emit
// JS/TypeScript/etc. The output here is unused in wasm interfac
let generated = if self.wasm_interface_types {
wit::section::add(&mut module)
.context("failed to generate a standard interface types section")?;
Generated::InterfaceTypes
} else {
let aux = module
.customs
.delete_typed::<wit::WasmBindgenAux>()
.expect("aux section should be present");
let adapters = module
.customs
.delete_typed::<wit::NonstandardWitSection>()
.unwrap();
let mut cx = js::Context::new(&mut module, self, &adapters, &aux)?;
cx.generate()?;
let (js, ts, start) = cx.finalize(stem)?;
Generated::Js(JsGenerated {
snippets: aux.snippets.clone(),
local_modules: aux.local_modules.clone(),
mode: self.mode.clone(),
typescript: self.typescript,
npm_dependencies: cx.npm_dependencies.clone(),
js,
ts,
start,
})
};
Ok(Output {
module,
stem: stem.to_string(),
generated,
})
}
fn local_module_name(&self, module: &str) -> String {
format!("./snippets/{}", module)
}
fn inline_js_module_name(
&self,
unique_crate_identifier: &str,
snippet_idx_in_crate: usize,
) -> String {
format!(
"./snippets/{}/inline{}.js",
unique_crate_identifier, snippet_idx_in_crate,
)
}
}
fn reset_indentation(s: &str) -> String {
let mut indent: u32 = 0;
let mut dst = String::new();
for line in s.lines() {
let line = line.trim();
if line.starts_with('}') || (line.ends_with('}') && !line.starts_with('*')) {
indent = indent.saturating_sub(1);
}
let extra = if line.starts_with(':') || line.starts_with('?') {
1
} else {
0
};
if !line.is_empty() {
for _ in 0..indent + extra {
dst.push_str(" ");
}
dst.push_str(line);
}
dst.push_str("\n");
// Ignore { inside of comments and if it's an exported enum
if line.ends_with('{') && !line.starts_with('*') && !line.ends_with("Object.freeze({") {
indent += 1;
}
}
return dst;
}
// Eventually these will all be CLI options, but while they're unstable features
// they're left as environment variables. We don't guarantee anything about
// backwards-compatibility with these options.
fn threads_config() -> wasm_bindgen_threads_xform::Config {
let mut cfg = wasm_bindgen_threads_xform::Config::new();
if let Ok(s) = env::var("WASM_BINDGEN_THREADS_MAX_MEMORY") {
cfg.maximum_memory(s.parse().unwrap());
}
if let Ok(s) = env::var("WASM_BINDGEN_THREADS_STACK_SIZE") {
cfg.thread_stack_size(s.parse().unwrap());
}
cfg
}
fn demangle(module: &mut Module) {
for func in module.funcs.iter_mut() {
let name = match &func.name {
Some(name) => name,
None => continue,
};
if let Ok(sym) = rustc_demangle::try_demangle(name) {
func.name = Some(sym.to_string());
}
}
}
impl OutputMode {
fn uses_es_modules(&self) -> bool {
match self {
OutputMode::Bundler { .. }
| OutputMode::Web
| OutputMode::Node {
experimental_modules: true,
}
| OutputMode::Deno => true,
_ => false,
}
}
fn nodejs_experimental_modules(&self) -> bool {
match self {
OutputMode::Node {
experimental_modules,
} => *experimental_modules,
_ => false,
}
}
fn nodejs(&self) -> bool {
match self {
OutputMode::Node { .. } => true,
_ => false,
}
}
fn no_modules(&self) -> bool {
match self {
OutputMode::NoModules { .. } => true,
_ => false,
}
}
fn always_run_in_browser(&self) -> bool {
match self {
OutputMode::Web => true,
OutputMode::NoModules { .. } => true,
OutputMode::Bundler { browser_only } => *browser_only,
_ => false,
}
}
fn web(&self) -> bool {
match self {
OutputMode::Web => true,
_ => false,
}
}
fn deno(&self) -> bool {
match self {
OutputMode::Deno { .. } => true,
_ => false,
}
}
fn esm_integration(&self) -> bool {
match self {
OutputMode::Bundler { .. }
| OutputMode::Node {
experimental_modules: true,
} => true,
_ => false,
}
}
}
/// Remove a number of internal exports that are synthesized by Rust's linker,
/// LLD. These exports aren't typically ever needed and just add extra space to
/// the binary.
fn unexported_unused_lld_things(module: &mut Module) {
let mut to_remove = Vec::new();
for export in module.exports.iter() {
match export.name.as_str() {
"__heap_base" | "__data_end" | "__indirect_function_table" => {
to_remove.push(export.id());
}
_ => {}
}
}
for id in to_remove {
module.exports.delete(id);
}
}
impl Output {
pub fn js(&self) -> &str {
match &self.generated {
Generated::InterfaceTypes => panic!("no js with interface types output"),
Generated::Js(gen) => &gen.js,
}
}
pub fn wasm(&self) -> &walrus::Module {
&self.module
}
pub fn wasm_mut(&mut self) -> &mut walrus::Module {
&mut self.module
}
pub fn emit(&mut self, out_dir: impl AsRef<Path>) -> Result<(), Error> {
self._emit(out_dir.as_ref())
}
fn _emit(&mut self, out_dir: &Path) -> Result<(), Error> {
let wasm_name = match &self.generated {
Generated::InterfaceTypes => self.stem.clone(),
Generated::Js(_) => format!("{}_bg", self.stem),
};
let wasm_path = out_dir.join(&wasm_name).with_extension("wasm");
fs::create_dir_all(out_dir)?;
let wasm_bytes = self.module.emit_wasm();
fs::write(&wasm_path, wasm_bytes)
.with_context(|| format!("failed to write `{}`", wasm_path.display()))?;
let gen = match &self.generated {
Generated::InterfaceTypes => return Ok(()),
Generated::Js(gen) => gen,
};
// Write out all local JS snippets to the final destination now that
// we've collected them from all the programs.
for (identifier, list) in gen.snippets.iter() {
for (i, js) in list.iter().enumerate() {
let name = format!("inline{}.js", i);
let path = out_dir.join("snippets").join(identifier).join(name);
fs::create_dir_all(path.parent().unwrap())?;
fs::write(&path, js)
.with_context(|| format!("failed to write `{}`", path.display()))?;
}
}
for (path, contents) in gen.local_modules.iter() {
let path = out_dir.join("snippets").join(path);
fs::create_dir_all(path.parent().unwrap())?;
fs::write(&path, contents)
.with_context(|| format!("failed to write `{}`", path.display()))?;
}
if gen.npm_dependencies.len() > 0 {
let map = gen
.npm_dependencies
.iter()
.map(|(k, v)| (k, &v.1))
.collect::<BTreeMap<_, _>>();
let json = serde_json::to_string_pretty(&map)?;
fs::write(out_dir.join("package.json"), json)?;
}
// And now that we've got all our JS and TypeScript, actually write it
// out to the filesystem.
let extension = if gen.mode.nodejs_experimental_modules() {
"mjs"
} else {
"js"
};
fn write<P, C>(path: P, contents: C) -> Result<(), anyhow::Error>
where
P: AsRef<Path>,
C: AsRef<[u8]>,
{
fs::write(&path, contents)
.with_context(|| format!("failed to write `{}`", path.as_ref().display()))
}
let js_path = out_dir.join(&self.stem).with_extension(extension);
if gen.mode.esm_integration() {
let js_name = format!("{}_bg.{}", self.stem, extension);
let start = gen.start.as_deref().unwrap_or("");
write(
&js_path,
format!(
"import * as wasm from \"./{}.wasm\";\nexport * from \"./{}\";{}",
wasm_name, js_name, start
),
)?;
write(&out_dir.join(&js_name), reset_indentation(&gen.js))?;
} else {
write(&js_path, reset_indentation(&gen.js))?;
}
if gen.typescript {
let ts_path = js_path.with_extension("d.ts");
fs::write(&ts_path, &gen.ts)
.with_context(|| format!("failed to write `{}`", ts_path.display()))?;
}
if gen.typescript {
let ts_path = wasm_path.with_extension("d.ts");
let ts = wasm2es6js::typescript(&self.module)?;
fs::write(&ts_path, ts)
.with_context(|| format!("failed to write `{}`", ts_path.display()))?;
}
Ok(())
}
}
fn gc_module_and_adapters(module: &mut Module) {
loop {
// Fist up, cleanup the native wasm module. Note that roots can come
// from custom sections, namely our wasm interface types custom section
// as well as the aux section.
walrus::passes::gc::run(module);
// ... and afterwards we can delete any `implements` directives for any
// imports that have been deleted.
let imports_remaining = module
.imports
.iter()
.map(|i| i.id())
.collect::<HashSet<_>>();
let mut section = module
.customs
.delete_typed::<wit::NonstandardWitSection>()
.unwrap();
section
.implements
.retain(|pair| imports_remaining.contains(&pair.0));
// ... and after we delete the `implements` directive we try to
// delete some adapters themselves. If nothing is deleted, then we're
// good to go. If something is deleted though then we may have free'd up
// some functions in the main module to get deleted, so go again to gc
// things.
let aux = module.customs.get_typed::<wit::WasmBindgenAux>().unwrap();
let any_removed = section.gc(aux);
module.customs.add(*section);
if !any_removed {
break;
}
}
}
/// Returns a sorted iterator over a hash map, sorted based on key.
///
/// The intention of this API is to be used whenever the iteration order of a
/// `HashMap` might affect the generated JS bindings. We want to ensure that the
/// generated output is deterministic and we do so by ensuring that iteration of
/// hash maps is consistently sorted.
fn sorted_iter<K, V>(map: &HashMap<K, V>) -> impl Iterator<Item = (&K, &V)>
where
K: Ord,
{
let mut pairs = map.iter().collect::<Vec<_>>();
pairs.sort_by_key(|(k, _)| *k);
pairs.into_iter()
}