514 lines
17 KiB
Rust

#![doc(html_root_url = "https://docs.rs/wasm-bindgen-cli-support/0.2")]
extern crate parity_wasm;
#[macro_use]
extern crate wasm_bindgen_shared as shared;
extern crate wasm_bindgen_gc as gc;
#[macro_use]
extern crate failure;
extern crate wasm_bindgen_threads_xform as threads_xform;
extern crate wasm_bindgen_wasm_interpreter as wasm_interpreter;
use std::collections::BTreeSet;
use std::env;
use std::fs;
use std::mem;
use std::path::{Path, PathBuf};
use std::str;
use failure::{Error, ResultExt};
use parity_wasm::elements::*;
mod decode;
mod descriptor;
mod js;
pub mod wasm2es6js;
mod wasm_utils;
pub struct Bindgen {
input: Input,
out_name: Option<String>,
nodejs: bool,
nodejs_experimental_modules: bool,
browser: bool,
no_modules: bool,
no_modules_global: Option<String>,
debug: bool,
typescript: bool,
demangle: bool,
keep_debug: bool,
remove_name_section: bool,
emit_start: bool,
// Experimental support for `WeakRefGroup`, an upcoming ECMAScript feature.
// Currently only enable-able through an env var.
weak_refs: bool,
// Experimental support for the wasm threads proposal, transforms the wasm
// module to be "ready to be instantiated on any thread"
threads: Option<threads_xform::Config>,
}
enum Input {
Path(PathBuf),
Module(Module, String),
None,
}
impl Bindgen {
pub fn new() -> Bindgen {
Bindgen {
input: Input::None,
out_name: None,
nodejs: false,
nodejs_experimental_modules: false,
browser: false,
no_modules: false,
no_modules_global: None,
debug: false,
typescript: false,
demangle: true,
keep_debug: false,
remove_name_section: false,
emit_start: true,
weak_refs: env::var("WASM_BINDGEN_WEAKREF").is_ok(),
threads: threads_config(),
}
}
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;
}
pub fn nodejs(&mut self, node: bool) -> &mut Bindgen {
self.nodejs = node;
self
}
pub fn nodejs_experimental_modules(&mut self, node: bool) -> &mut Bindgen {
self.nodejs_experimental_modules = node;
self
}
pub fn browser(&mut self, browser: bool) -> &mut Bindgen {
self.browser = browser;
self
}
pub fn no_modules(&mut self, no_modules: bool) -> &mut Bindgen {
self.no_modules = no_modules;
self
}
pub fn no_modules_global(&mut self, name: &str) -> &mut Bindgen {
self.no_modules_global = Some(name.to_string());
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 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 emit_start(&mut self, emit: bool) -> &mut Bindgen {
self.emit_start = emit;
self
}
pub fn generate<P: AsRef<Path>>(&mut self, path: P) -> Result<(), Error> {
self._generate(path.as_ref())
}
fn _generate(&mut self, out_dir: &Path) -> Result<(), 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::new(Vec::new());
(mem::replace(m, blank_module), &name[..])
}
Input::Path(ref path) => {
let contents = fs::read(&path)
.with_context(|_| format!("failed to read `{}`", path.display()))?;
let module = parity_wasm::deserialize_buffer::<Module>(&contents)
.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)
}
};
let mut program_storage = Vec::new();
let programs = extract_programs(&mut module, &mut program_storage)
.with_context(|_| "failed to extract wasm-bindgen custom sections")?;
if let Some(cfg) = &self.threads {
cfg.run(&mut module)
.with_context(|_| "failed to prepare module for threading")?;
}
// Here we're actually instantiating the module we've parsed above for
// execution. Why, you might be asking, are we executing wasm code? A
// good question!
//
// Transmitting information from `#[wasm_bindgen]` here to the CLI tool
// is pretty tricky. Specifically information about the types involved
// with a function signature (especially generic ones) can be hefty to
// translate over. As a result, the macro emits a bunch of shims which,
// when executed, will describe to us what the types look like.
//
// This means that whenever we encounter an import or export we'll
// execute a shim function which informs us about its type so we can
// then generate the appropriate bindings.
let mut instance = wasm_interpreter::Interpreter::new(&module);
let (js, ts) = {
let mut cx = js::Context {
globals: String::new(),
imports: String::new(),
imports_post: String::new(),
footer: String::new(),
typescript: format!("/* tslint:disable */\n"),
exposed_globals: Default::default(),
required_internal_exports: Default::default(),
imported_names: Default::default(),
imported_identifiers: Default::default(),
exported_classes: Default::default(),
config: &self,
module: &mut module,
function_table_needed: false,
interpreter: &mut instance,
memory_init: None,
imported_functions: Default::default(),
imported_statics: Default::default(),
direct_imports: Default::default(),
start: None,
};
cx.parse_wasm_names();
for program in programs.iter() {
js::SubContext {
program,
cx: &mut cx,
vendor_prefixes: Default::default(),
}
.generate()?;
}
cx.finalize(stem)?
};
let extension = if self.nodejs_experimental_modules {
"mjs"
} else {
"js"
};
let js_path = out_dir.join(stem).with_extension(extension);
fs::write(&js_path, reset_indentation(&js))
.with_context(|_| format!("failed to write `{}`", js_path.display()))?;
if self.typescript {
let ts_path = js_path.with_extension("d.ts");
fs::write(&ts_path, ts)
.with_context(|_| format!("failed to write `{}`", ts_path.display()))?;
}
let wasm_path = out_dir.join(format!("{}_bg", stem)).with_extension("wasm");
if self.nodejs {
let js_path = wasm_path.with_extension(extension);
let shim = self.generate_node_wasm_import(&module, &wasm_path);
fs::write(&js_path, shim)
.with_context(|_| format!("failed to write `{}`", js_path.display()))?;
}
if self.typescript {
let ts_path = wasm_path.with_extension("d.ts");
let ts = wasm2es6js::typescript(&module);
fs::write(&ts_path, ts)
.with_context(|_| format!("failed to write `{}`", ts_path.display()))?;
}
let wasm_bytes = parity_wasm::serialize(module)?;
fs::write(&wasm_path, wasm_bytes)
.with_context(|_| format!("failed to write `{}`", wasm_path.display()))?;
Ok(())
}
fn generate_node_wasm_import(&self, m: &Module, path: &Path) -> String {
let mut imports = BTreeSet::new();
if let Some(i) = m.import_section() {
for i in i.entries() {
imports.insert(i.module());
}
}
let mut shim = String::new();
if self.nodejs_experimental_modules {
for (i, module) in imports.iter().enumerate() {
shim.push_str(&format!("import * as import{} from '{}';\n", i, module));
}
// On windows skip the leading `/` which comes out when we parse a
// url to use `C:\...` instead of `\C:\...`
shim.push_str(&format!(
"
import * as path from 'path';
import * as fs from 'fs';
import * as url from 'url';
import * as process from 'process';
let file = path.dirname(url.parse(import.meta.url).pathname);
if (process.platform === 'win32') {{
file = file.substring(1);
}}
const bytes = fs.readFileSync(path.join(file, '{}'));
",
path.file_name().unwrap().to_str().unwrap()
));
} else {
shim.push_str(&format!(
"
const path = require('path').join(__dirname, '{}');
const bytes = require('fs').readFileSync(path);
",
path.file_name().unwrap().to_str().unwrap()
));
}
shim.push_str("let imports = {};\n");
for (i, module) in imports.iter().enumerate() {
if self.nodejs_experimental_modules {
shim.push_str(&format!("imports['{}'] = import{};\n", module, i));
} else {
shim.push_str(&format!("imports['{0}'] = require('{0}');\n", module));
}
}
shim.push_str(&format!(
"
const wasmModule = new WebAssembly.Module(bytes);
const wasmInstance = new WebAssembly.Instance(wasmModule, imports);
",
));
if self.nodejs_experimental_modules {
if let Some(e) = m.export_section() {
for name in e.entries().iter().map(|e| e.field()) {
shim.push_str("export const ");
shim.push_str(name);
shim.push_str(" = wasmInstance.exports.");
shim.push_str(name);
shim.push_str(";\n");
}
}
} else {
shim.push_str("module.exports = wasmInstance.exports;\n");
}
reset_indentation(&shim)
}
}
fn extract_programs<'a>(
module: &mut Module,
program_storage: &'a mut Vec<Vec<u8>>,
) -> Result<Vec<decode::Program<'a>>, Error> {
let my_version = shared::version();
let mut to_remove = Vec::new();
assert!(program_storage.is_empty());
for (i, s) in module.sections_mut().iter_mut().enumerate() {
let custom = match s {
Section::Custom(s) => s,
_ => continue,
};
if custom.name() != "__wasm_bindgen_unstable" {
continue;
}
to_remove.push(i);
program_storage.push(mem::replace(custom.payload_mut(), Vec::new()));
}
for i in to_remove.into_iter().rev() {
module.sections_mut().remove(i);
}
let mut ret = Vec::new();
for program in program_storage.iter() {
let mut payload = &program[..];
while let Some(data) = get_remaining(&mut payload) {
// Historical versions of wasm-bindgen have used JSON as the custom
// data section format. Newer versions, however, are using a custom
// serialization protocol that looks much more like the wasm spec.
//
// We, however, want a sanity check to ensure that if we're running
// against the wrong wasm-bindgen we get a nicer error than an
// internal decode error. To that end we continue to verify a tiny
// bit of json at the beginning of each blob before moving to the
// next blob. This should keep us compatible with older wasm-bindgen
// instances as well as forward-compatible for now.
//
// Note, though, that as `wasm-pack` picks up steam it's hoped we
// can just delete this entirely. The `wasm-pack` project already
// manages versions for us, so we in theory should need this check
// less and less over time.
if let Some(their_version) = verify_schema_matches(data)? {
bail!(
"
it looks like the Rust project used to create this wasm file was linked against
a different version of wasm-bindgen than this binary:
rust wasm file: {}
this binary: {}
Currently the bindgen format is unstable enough that these two version must
exactly match, so it's required that these two version are kept in sync by
either updating the wasm-bindgen dependency or this binary. You should be able
to update the wasm-bindgen dependency with:
cargo update -p wasm-bindgen
or you can update the binary with
cargo install -f wasm-bindgen-cli
if this warning fails to go away though and you're not sure what to do feel free
to open an issue at https://github.com/rustwasm/wasm-bindgen/issues!
",
their_version,
my_version,
);
}
let next = get_remaining(&mut payload).unwrap();
ret.push(<decode::Program as decode::Decode>::decode_all(next));
}
}
Ok(ret)
}
fn get_remaining<'a>(data: &mut &'a [u8]) -> Option<&'a [u8]> {
if data.len() == 0 {
return None;
}
let len = ((data[0] as usize) << 0)
| ((data[1] as usize) << 8)
| ((data[2] as usize) << 16)
| ((data[3] as usize) << 24);
let (a, b) = data[4..].split_at(len);
*data = b;
Some(a)
}
fn verify_schema_matches<'a>(data: &'a [u8]) -> Result<Option<&'a str>, Error> {
macro_rules! bad {
() => {
bail!("failed to decode what looked like wasm-bindgen data")
};
}
let data = match str::from_utf8(data) {
Ok(s) => s,
Err(_) => bad!(),
};
if !data.starts_with("{") || !data.ends_with("}") {
bad!()
}
let needle = "\"schema_version\":\"";
let rest = match data.find(needle) {
Some(i) => &data[i + needle.len()..],
None => bad!(),
};
let their_schema_version = match rest.find("\"") {
Some(i) => &rest[..i],
None => bad!(),
};
if their_schema_version == shared::SCHEMA_VERSION {
return Ok(None);
}
let needle = "\"version\":\"";
let rest = match data.find(needle) {
Some(i) => &data[i + needle.len()..],
None => bad!(),
};
let their_version = match rest.find("\"") {
Some(i) => &rest[..i],
None => bad!(),
};
Ok(Some(their_version))
}
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");
if line.ends_with('{') {
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() -> Option<threads_xform::Config> {
if env::var("WASM_BINDGEN_THREADS").is_err() {
return None;
}
let mut cfg = 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());
}
Some(cfg)
}