use std::collections::{HashMap, HashSet};
use std::mem;
use decode;
use failure::{Error, ResultExt};
use gc;
use parity_wasm::elements::Error as ParityError;
use parity_wasm::elements::*;
use shared;
use super::Bindgen;
use descriptor::{Descriptor, VectorKind};
use wasm_interpreter::Interpreter;
use wasm_utils::Remap;
mod js2rust;
use self::js2rust::Js2Rust;
mod rust2js;
use self::rust2js::Rust2Js;
mod closures;
pub struct Context<'a> {
pub globals: String,
pub imports: String,
pub imports_post: String,
pub footer: String,
pub typescript: String,
pub exposed_globals: Option<HashSet<&'static str>>,
pub required_internal_exports: HashSet<&'static str>,
pub imported_functions: HashSet<&'a str>,
pub imported_statics: HashSet<&'a str>,
pub config: &'a Bindgen,
pub module: &'a mut Module,
pub start: Option<String>,
/// A map which maintains a list of what identifiers we've imported and what
/// they're named locally.
///
/// The `Option<String>` key is the module that identifiers were imported
/// from, `None` being the global module. The second key is a map of
/// identifiers we've already imported from the module to what they're
/// called locally.
pub imported_names: HashMap<Option<&'a str>, HashMap<&'a str, String>>,
/// A set of all imported identifiers to the number of times they've been
/// imported, used to generate new identifiers.
pub imported_identifiers: HashMap<String, usize>,
/// A map of all imported shim functions which can actually be directly
/// imported from the containing module. The mapping here maps to a tuple,
/// where the first element is the module to import from and the second
/// element is the name to import from the module.
///
/// Note that for `direct_imports` no shims are generated in JS that
/// wasm-bindgen emits.
pub direct_imports: HashMap<&'a str, (&'a str, &'a str)>,
pub exported_classes: Option<HashMap<String, ExportedClass>>,
pub function_table_needed: bool,
pub interpreter: &'a mut Interpreter,
pub memory_init: Option<ResizableLimits>,
}
#[derive(Default)]
pub struct ExportedClass {
comments: String,
contents: String,
typescript: String,
has_constructor: bool,
wrap_needed: bool,
}
pub struct SubContext<'a, 'b: 'a> {
pub program: &'b decode::Program<'b>,
pub cx: &'a mut Context<'b>,
pub vendor_prefixes: HashMap<&'b str, Vec<&'b str>>,
}
pub enum ImportTarget {
Function(String),
Method(String),
Constructor(String),
StructuralMethod(String),
StructuralGetter(Option<String>, String),
StructuralSetter(Option<String>, String),
StructuralIndexingGetter(Option<String>),
StructuralIndexingSetter(Option<String>),
StructuralIndexingDeleter(Option<String>),
}
/// Return value of `determine_import` which is where we look at an imported
/// function AST and figure out where it's actually being imported from
/// (performing some validation checks and whatnot).
enum Import<'a> {
/// An item is imported from the global scope. The `name` is what's imported
/// and the optional `field` is the field on that item we're importing.
Global {
name: &'a str,
field: Option<&'a str>,
},
/// Same as `Global`, except the `name` is imported via an ESM import from
/// the specified `module` path.
Module {
module: &'a str,
name: &'a str,
field: Option<&'a str>,
},
/// A global import which may have a number of vendor prefixes associated
/// with it, like `webkitAudioPrefix`. The `name` is the name to test
/// whether it's prefixed.
VendorPrefixed {
name: &'a str,
prefixes: Vec<&'a str>,
},
}
const INITIAL_HEAP_VALUES: &[&str] = &["undefined", "null", "true", "false"];
// Must be kept in sync with `src/lib.rs` of the `wasm-bindgen` crate
const INITIAL_HEAP_OFFSET: usize = 32;
impl<'a> Context<'a> {
fn should_write_global(&mut self, name: &'static str) -> bool {
self.exposed_globals.as_mut().unwrap().insert(name)
}
fn export(&mut self, name: &str, contents: &str, comments: Option<String>) {
let contents = contents.trim();
if let Some(ref c) = comments {
self.globals.push_str(c);
}
let global = if self.use_node_require() {
if contents.starts_with("class") {
format!("{1}\nmodule.exports.{0} = {0};\n", name, contents)
} else {
format!("module.exports.{} = {};\n", name, contents)
}
} else if self.config.no_modules {
if contents.starts_with("class") {
format!("{1}\n__exports.{0} = {0};\n", name, contents)
} else {
format!("__exports.{} = {};\n", name, contents)
}
} else {
if contents.starts_with("function") {
format!("export function {}{}\n", name, &contents[8..])
} else if contents.starts_with("class") {
format!("export {}\n", contents)
} else {
format!("export const {} = {};\n", name, contents)
}
};
self.global(&global);
}
fn require_internal_export(&mut self, name: &'static str) -> Result<(), Error> {
if !self.required_internal_exports.insert(name) {
return Ok(());
}
if let Some(s) = self.module.export_section() {
if s.entries().iter().any(|e| e.field() == name) {
return Ok(());
}
}
bail!(
"the exported function `{}` is required to generate bindings \
but it was not found in the wasm file, perhaps the `std` feature \
of the `wasm-bindgen` crate needs to be enabled?",
name
);
}
pub fn finalize(&mut self, module_name: &str) -> Result<(String, String), Error> {
self.bind("__wbindgen_object_clone_ref", &|me| {
me.expose_get_object();
me.expose_add_heap_object();
Ok(String::from(
"
function(idx) {
return addHeapObject(getObject(idx));
}
",
))
})?;
self.bind("__wbindgen_object_drop_ref", &|me| {
me.expose_drop_ref();
Ok(String::from("function(i) { dropObject(i); }"))
})?;
self.bind("__wbindgen_string_new", &|me| {
me.expose_add_heap_object();
me.expose_get_string_from_wasm();
Ok(String::from(
"
function(p, l) {
return addHeapObject(getStringFromWasm(p, l));
}
",
))
})?;
self.bind("__wbindgen_number_new", &|me| {
me.expose_add_heap_object();
Ok(String::from("function(i) { return addHeapObject(i); }"))
})?;
self.bind("__wbindgen_number_get", &|me| {
me.expose_get_object();
me.expose_uint8_memory();
Ok(String::from(
"
function(n, invalid) {
let obj = getObject(n);
if (typeof(obj) === 'number') return obj;
getUint8Memory()[invalid] = 1;
return 0;
}
",
))
})?;
self.bind("__wbindgen_is_null", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(idx) {
return getObject(idx) === null ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_is_undefined", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(idx) {
return getObject(idx) === undefined ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_boolean_get", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(i) {
let v = getObject(i);
if (typeof(v) === 'boolean') {
return v ? 1 : 0;
} else {
return 2;
}
}
",
))
})?;
self.bind("__wbindgen_symbol_new", &|me| {
me.expose_get_string_from_wasm();
me.expose_add_heap_object();
Ok(String::from(
"
function(ptr, len) {
let a;
if (ptr === 0) {
a = Symbol();
} else {
a = Symbol(getStringFromWasm(ptr, len));
}
return addHeapObject(a);
}
",
))
})?;
self.bind("__wbindgen_is_symbol", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(i) {
return typeof(getObject(i)) === 'symbol' ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_is_object", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(i) {
const val = getObject(i);
return typeof(val) === 'object' && val !== null ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_is_function", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(i) {
return typeof(getObject(i)) === 'function' ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_is_string", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(i) {
return typeof(getObject(i)) === 'string' ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_string_get", &|me| {
me.expose_pass_string_to_wasm()?;
me.expose_get_object();
me.expose_uint32_memory();
Ok(String::from(
"
function(i, len_ptr) {
let obj = getObject(i);
if (typeof(obj) !== 'string') return 0;
const ptr = passStringToWasm(obj);
getUint32Memory()[len_ptr / 4] = WASM_VECTOR_LEN;
return ptr;
}
",
))
})?;
self.bind("__wbindgen_debug_string", &|me| {
me.expose_pass_string_to_wasm()?;
me.expose_get_object();
me.expose_uint32_memory();
Ok(String::from(
"
function(i, len_ptr) {
const toString = Object.prototype.toString;
const debug_str = val => {
// primitive types
const type = typeof val;
if (type == 'number' || type == 'boolean' || val == null) {
return `${val}`;
}
if (type == 'string') {
return `\"${val}\"`;
}
if (type == 'symbol') {
const description = val.description;
if (description == null) {
return 'Symbol';
} else {
return `Symbol(${description})`;
}
}
if (type == 'function') {
const name = val.name;
if (typeof name == 'string' && name.length > 0) {
return `Function(${name})`;
} else {
return 'Function';
}
}
// objects
if (Array.isArray(val)) {
const length = val.length;
let debug = '[';
if (length > 0) {
debug += debug_str(val[0]);
}
for(let i = 1; i < length; i++) {
debug += ', ' + debug_str(val[i]);
}
debug += ']';
return debug;
}
// Test for built-in
const builtInMatches = /\\[object ([^\\]]+)\\]/.exec(toString.call(val));
let className;
if (builtInMatches.length > 1) {
className = builtInMatches[1];
} else {
// Failed to match the standard '[object ClassName]'
return toString.call(val);
}
if (className == 'Object') {
// we're a user defined class or Object
// JSON.stringify avoids problems with cycles, and is generally much
// easier than looping through ownProperties of `val`.
try {
return 'Object(' + JSON.stringify(val) + ')';
} catch (_) {
return 'Object';
}
}
// errors
if (val instanceof Error) {
return `${val.name}: ${val.message}\n${val.stack}`;
}
// TODO we could test for more things here, like `Set`s and `Map`s.
return className;
};
const val = getObject(i);
const debug = debug_str(val);
const ptr = passStringToWasm(debug);
getUint32Memory()[len_ptr / 4] = WASM_VECTOR_LEN;
return ptr;
}
",
))
})?;
self.bind("__wbindgen_cb_drop", &|me| {
me.expose_drop_ref();
Ok(String::from(
"
function(i) {
const obj = getObject(i).original;
dropObject(i);
if (obj.cnt-- == 1) {
obj.a = 0;
return 1;
}
return 0;
}
",
))
})?;
self.bind("__wbindgen_cb_forget", &|me| {
me.expose_drop_ref();
Ok("dropObject".to_string())
})?;
self.bind("__wbindgen_json_parse", &|me| {
me.expose_add_heap_object();
me.expose_get_string_from_wasm();
Ok(String::from(
"
function(ptr, len) {
return addHeapObject(JSON.parse(getStringFromWasm(ptr, len)));
}
",
))
})?;
self.bind("__wbindgen_json_serialize", &|me| {
me.expose_get_object();
me.expose_pass_string_to_wasm()?;
me.expose_uint32_memory();
Ok(String::from(
"
function(idx, ptrptr) {
const ptr = passStringToWasm(JSON.stringify(getObject(idx)));
getUint32Memory()[ptrptr / 4] = ptr;
return WASM_VECTOR_LEN;
}
",
))
})?;
self.bind("__wbindgen_jsval_eq", &|me| {
me.expose_get_object();
Ok(String::from(
"
function(a, b) {
return getObject(a) === getObject(b) ? 1 : 0;
}
",
))
})?;
self.bind("__wbindgen_memory", &|me| {
me.expose_add_heap_object();
let mem = me.memory();
Ok(format!("function() {{ return addHeapObject({}); }}", mem))
})?;
self.bind("__wbindgen_module", &|me| {
if !me.config.no_modules {
bail!(
"`wasm_bindgen::module` is currently only supported with \
--no-modules"
);
}
me.expose_add_heap_object();
Ok(format!(
"
function() {{
return addHeapObject(init.__wbindgen_wasm_module);
}}
",
))
})?;
self.bind("__wbindgen_rethrow", &|me| {
me.expose_take_object();
Ok(String::from("function(idx) { throw takeObject(idx); }"))
})?;
closures::rewrite(self).with_context(|_| "failed to generate internal closure shims")?;
self.write_classes()?;
self.unexport_unused_internal_exports();
// Handle the `start` function, if one was specified. If we're in a
// --test mode (such as wasm-bindgen-test-runner) then we skip this
// entirely. Otherwise we want to first add a start function to the
// `start` section if one is specified.
//
// Afterwards, we need to perform what's a bit of a hack. Right after we
// added the start function, we remove it again because no current
// strategy for bundlers and deployment works well enough with it. For
// `--no-modules` output we need to be sure to call the start function
// after our exports are wired up (or most imported functions won't
// work).
//
// For ESM outputs bundlers like webpack also don't work because
// currently they run the wasm initialization before the JS glue
// initialization, meaning that if the wasm start function calls
// imported functions the JS glue isn't ready to go just yet.
//
// To handle `--no-modules` we just unstart the start function and call
// it manually. To handle the ESM use case we switch the start function
// to calling an imported function which defers the start function via
// `Promise.resolve().then(...)` to execute on the next microtask tick.
let mut has_start_function = false;
if self.config.emit_start {
self.add_start_function()?;
has_start_function = self.unstart_start_function();
if has_start_function && !self.config.no_modules {
self.inject_start_shim();
}
}
self.export_table();
self.gc();
// Note that it's important `throw` comes last *after* we gc. The
// `__wbindgen_malloc` function may call this but we only want to
// generate code for this if it's actually live (and __wbindgen_malloc
// isn't gc'd).
self.bind("__wbindgen_throw", &|me| {
me.expose_get_string_from_wasm();
Ok(String::from(
"
function(ptr, len) {
throw new Error(getStringFromWasm(ptr, len));
}
",
))
})?;
self.rewrite_imports(module_name);
self.update_producers_section();
// Cause any future calls to `should_write_global` to panic, making sure
// we don't ask for items which we can no longer emit.
drop(self.exposed_globals.take().unwrap());
let mut js = if self.config.threads.is_some() {
// TODO: It's not clear right now how to best use threads with
// bundlers like webpack. We need a way to get the existing
// module/memory into web workers for now and we don't quite know
// idiomatically how to do that! In the meantime, always require
// `--no-modules`
if !self.config.no_modules {
bail!("most use `--no-modules` with threads for now")
}
self.memory(); // set `memory_limit` if it's not already set
let limits = match &self.memory_init {
Some(l) if l.shared() => l.clone(),
_ => bail!("must impot a shared memory with threads"),
};
let mut memory = String::from("new WebAssembly.Memory({");
memory.push_str(&format!("initial:{}", limits.initial()));
if let Some(max) = limits.maximum() {
memory.push_str(&format!(",maximum:{}", max));
}
if limits.shared() {
memory.push_str(",shared:true");
}
memory.push_str("})");
format!(
"\
(function() {{
var wasm;
var memory;
const __exports = {{}};
{globals}
function init(module_or_path, maybe_memory) {{
let result;
const imports = {{ './{module}': __exports }};
if (module_or_path instanceof WebAssembly.Module) {{
memory = __exports.memory = maybe_memory;
result = WebAssembly.instantiate(module_or_path, imports)
.then(instance => {{
return {{ instance, module: module_or_path }}
}});
}} else {{
memory = __exports.memory = {init_memory};
const response = fetch(module_or_path);
if (typeof WebAssembly.instantiateStreaming === 'function') {{
result = WebAssembly.instantiateStreaming(response, imports);
}} else {{
result = response
.then(r => r.arrayBuffer())
.then(bytes => WebAssembly.instantiate(bytes, imports));
}}
}}
return result.then(({{instance, module}}) => {{
wasm = init.wasm = instance.exports;
init.__wbindgen_wasm_instance = instance;
init.__wbindgen_wasm_module = module;
init.__wbindgen_wasm_memory = __exports.memory;
{start}
}});
}};
self.{global_name} = Object.assign(init, __exports);
}})();",
globals = self.globals,
module = module_name,
global_name = self
.config
.no_modules_global
.as_ref()
.map(|s| &**s)
.unwrap_or("wasm_bindgen"),
init_memory = memory,
start = if has_start_function {
"wasm.__wbindgen_start();"
} else {
""
},
)
} else if self.config.no_modules {
format!(
"\
(function() {{
var wasm;
const __exports = {{}};
{globals}
function init(path_or_module) {{
let instantiation;
const imports = {{ './{module}': __exports }};
if (path_or_module instanceof WebAssembly.Module) {{
instantiation = WebAssembly.instantiate(path_or_module, imports)
.then(instance => {{
return {{ instance, module: path_or_module }}
}});
}} else {{
const data = fetch(path_or_module);
if (typeof WebAssembly.instantiateStreaming === 'function') {{
instantiation = WebAssembly.instantiateStreaming(data, imports);
}} else {{
instantiation = data
.then(response => response.arrayBuffer())
.then(buffer => WebAssembly.instantiate(buffer, imports));
}}
}}
return instantiation.then(({{instance}}) => {{
wasm = init.wasm = instance.exports;
{start}
}});
}};
self.{global_name} = Object.assign(init, __exports);
}})();",
globals = self.globals,
module = module_name,
global_name = self
.config
.no_modules_global
.as_ref()
.map(|s| &**s)
.unwrap_or("wasm_bindgen"),
start = if has_start_function {
"wasm.__wbindgen_start();"
} else {
""
},
)
} else {
let import_wasm = if self.globals.len() == 0 {
String::new()
} else if self.use_node_require() {
self.footer
.push_str(&format!("wasm = require('./{}_bg');", module_name));
format!("var wasm;")
} else {
format!("import * as wasm from './{}_bg';", module_name)
};
format!(
"\
/* tslint:disable */\n\
{import_wasm}\n\
{imports}\n\
{imports_post}\n\
{globals}\n\
{footer}",
import_wasm = import_wasm,
globals = self.globals,
imports = self.imports,
imports_post = self.imports_post,
footer = self.footer,
)
};
while js.contains("\n\n\n") {
js = js.replace("\n\n\n", "\n\n");
}
Ok((js, self.typescript.clone()))
}
fn bind(
&mut self,
name: &str,
f: &Fn(&mut Self) -> Result<String, Error>,
) -> Result<(), Error> {
if !self.wasm_import_needed(name) {
return Ok(());
}
let contents = f(self)
.with_context(|_| format!("failed to generate internal JS function `{}`", name))?;
self.export(name, &contents, None);
Ok(())
}
fn write_classes(&mut self) -> Result<(), Error> {
for (class, exports) in self.exported_classes.take().unwrap() {
self.write_class(&class, &exports)?;
}
Ok(())
}
fn write_class(&mut self, name: &str, class: &ExportedClass) -> Result<(), Error> {
let mut dst = format!("class {} {{\n", name);
let mut ts_dst = format!("export {}", dst);
let (mkweakref, freeref) = if self.config.weak_refs {
// When weak refs are enabled we use them to automatically free the
// contents of an exported rust class when it's gc'd. Note that a
// manual `free` function still exists for deterministic
// destruction.
//
// This is implemented by using a `WeakRefGroup` to run finalizers
// for all `WeakRef` objects that it creates. Upon construction of
// a new wasm object we use `makeRef` with "holdings" of a thunk to
// free the wasm instance. Once the `this` (the instance we're
// creating) is gc'd then the finalizer will run with the
// `WeakRef`, and we'll pull out the `holdings`, our pointer.
//
// Note, though, that if manual finalization happens we want to
// cancel the `WeakRef`-generated finalization, so we retain the
// `WeakRef` in a global map. This global map is then used to
// `drop()` the `WeakRef` (cancel finalization) whenever it is
// finalized.
self.expose_cleanup_groups();
let mk = format!("addCleanup(this, this.ptr, free{});", name);
let free = "
CLEANUPS_MAP.get(ptr).drop();
CLEANUPS_MAP.delete(ptr);
";
(mk, free)
} else {
(String::new(), "")
};
if self.config.debug && !class.has_constructor {
dst.push_str(
"
constructor() {
throw new Error('cannot invoke `new` directly');
}
",
);
}
let mut wrap_needed = class.wrap_needed;
let new_name = shared::new_function(&name);
if self.wasm_import_needed(&new_name) {
self.expose_add_heap_object();
wrap_needed = true;
self.export(
&new_name,
&format!(
"
function(ptr) {{
return addHeapObject({}.__wrap(ptr));
}}
",
name
),
None,
);
}
if wrap_needed {
dst.push_str(&format!(
"
static __wrap(ptr) {{
const obj = Object.create({}.prototype);
obj.ptr = ptr;
{}
return obj;
}}
",
name,
mkweakref.replace("this", "obj"),
));
}
self.global(&format!(
"
function free{}(ptr) {{
{}
wasm.{}(ptr);
}}
",
name,
freeref,
shared::free_function(&name)
));
dst.push_str(&format!(
"
free() {{
const ptr = this.ptr;
this.ptr = 0;
free{}(ptr);
}}
",
name,
));
ts_dst.push_str(" free(): void;\n");
dst.push_str(&class.contents);
ts_dst.push_str(&class.typescript);
dst.push_str("}\n");
ts_dst.push_str("}\n");
self.export(&name, &dst, Some(class.comments.clone()));
self.typescript.push_str(&ts_dst);
Ok(())
}
fn export_table(&mut self) {
if !self.function_table_needed {
return;
}
for section in self.module.sections_mut() {
let exports = match *section {
Section::Export(ref mut s) => s,
_ => continue,
};
let entry = ExportEntry::new("__wbg_function_table".to_string(), Internal::Table(0));
exports.entries_mut().push(entry);
break;
}
}
fn rewrite_imports(&mut self, module_name: &str) {
for (name, contents) in self._rewrite_imports(module_name) {
self.export(&name, &contents, None);
}
}
fn _rewrite_imports(&mut self, module_name: &str) -> Vec<(String, String)> {
let mut math_imports = Vec::new();
let imports = self
.module
.sections_mut()
.iter_mut()
.filter_map(|s| match *s {
Section::Import(ref mut s) => Some(s),
_ => None,
})
.flat_map(|s| s.entries_mut());
for import in imports {
if import.module() == "__wbindgen_placeholder__" {
import.module_mut().truncate(0);
if let Some((module, name)) = self.direct_imports.get(import.field()) {
import.field_mut().truncate(0);
import.module_mut().push_str(module);
import.field_mut().push_str(name);
} else {
import.module_mut().push_str("./");
import.module_mut().push_str(module_name);
}
continue;
}
if import.module() != "env" {
continue;
}
// If memory is imported we'll have exported it from the shim module
// so let's import it from there.
if import.field() == "memory" {
import.module_mut().truncate(0);
import.module_mut().push_str("./");
import.module_mut().push_str(module_name);
continue;
}
let renamed_import = format!("__wbindgen_{}", import.field());
let mut bind_math = |expr: &str| {
math_imports.push((renamed_import.clone(), format!("function{}", expr)));
};
// FIXME(#32): try to not use function shims
match import.field() {
"Math_acos" => bind_math("(x) { return Math.acos(x); }"),
"Math_asin" => bind_math("(x) { return Math.asin(x); }"),
"Math_atan" => bind_math("(x) { return Math.atan(x); }"),
"Math_atan2" => bind_math("(x, y) { return Math.atan2(x, y); }"),
"Math_cbrt" => bind_math("(x) { return Math.cbrt(x); }"),
"Math_cosh" => bind_math("(x) { return Math.cosh(x); }"),
"Math_expm1" => bind_math("(x) { return Math.expm1(x); }"),
"Math_hypot" => bind_math("(x, y) { return Math.hypot(x, y); }"),
"Math_log1p" => bind_math("(x) { return Math.log1p(x); }"),
"Math_sinh" => bind_math("(x) { return Math.sinh(x); }"),
"Math_tan" => bind_math("(x) { return Math.tan(x); }"),
"Math_tanh" => bind_math("(x) { return Math.tanh(x); }"),
_ => continue,
}
import.module_mut().truncate(0);
import.module_mut().push_str("./");
import.module_mut().push_str(module_name);
*import.field_mut() = renamed_import.clone();
}
math_imports
}
fn unexport_unused_internal_exports(&mut self) {
let required = &self.required_internal_exports;
for section in self.module.sections_mut() {
let exports = match *section {
Section::Export(ref mut s) => s,
_ => continue,
};
exports.entries_mut().retain(|export| {
!export.field().starts_with("__wbindgen") || required.contains(export.field())
});
}
}
fn expose_drop_ref(&mut self) {
if !self.should_write_global("drop_ref") {
return;
}
self.expose_global_heap();
self.expose_global_heap_next();
// Note that here we check if `idx` shouldn't actually be dropped. This
// is due to the fact that `JsValue::null()` and friends can be passed
// by value to JS where we'll automatically call this method. Those
// constants, however, cannot be dropped. See #1054 for removing this
// branch.
//
// Otherwise the free operation here is pretty simple, just appending to
// the linked list of heap slots that are free.
self.global(&format!(
"
function dropObject(idx) {{
if (idx < {}) return;
heap[idx] = heap_next;
heap_next = idx;
}}
",
INITIAL_HEAP_OFFSET + INITIAL_HEAP_VALUES.len(),
));
}
fn expose_global_heap(&mut self) {
if !self.should_write_global("heap") {
return;
}
self.global(&format!("const heap = new Array({});", INITIAL_HEAP_OFFSET));
self.global("heap.fill(undefined);");
self.global(&format!("heap.push({});", INITIAL_HEAP_VALUES.join(", ")));
}
fn expose_global_heap_next(&mut self) {
if !self.should_write_global("heap_next") {
return;
}
self.expose_global_heap();
self.global("let heap_next = heap.length;");
}
fn expose_get_object(&mut self) {
if !self.should_write_global("get_object") {
return;
}
self.expose_global_heap();
// Accessing a heap object is just a simple index operation due to how
// the stack/heap are laid out.
self.global("function getObject(idx) { return heap[idx]; }");
}
fn expose_assert_num(&mut self) {
if !self.should_write_global("assert_num") {
return;
}
self.global(&format!(
"
function _assertNum(n) {{
if (typeof(n) !== 'number') throw new Error('expected a number argument');
}}
"
));
}
fn expose_assert_bool(&mut self) {
if !self.should_write_global("assert_bool") {
return;
}
self.global(&format!(
"
function _assertBoolean(n) {{
if (typeof(n) !== 'boolean') {{
throw new Error('expected a boolean argument');
}}
}}
"
));
}
fn expose_wasm_vector_len(&mut self) {
if !self.should_write_global("wasm_vector_len") {
return;
}
self.global("let WASM_VECTOR_LEN = 0;");
}
fn expose_pass_string_to_wasm(&mut self) -> Result<(), Error> {
if !self.should_write_global("pass_string_to_wasm") {
return Ok(());
}
self.require_internal_export("__wbindgen_malloc")?;
self.expose_text_encoder();
self.expose_uint8_memory();
self.expose_wasm_vector_len();
let debug = if self.config.debug {
"
if (typeof(arg) !== 'string') throw new Error('expected a string argument');
"
} else {
""
};
self.global(&format!(
"
function passStringToWasm(arg) {{
{}
const buf = cachedTextEncoder.encode(arg);
const ptr = wasm.__wbindgen_malloc(buf.length);
getUint8Memory().set(buf, ptr);
WASM_VECTOR_LEN = buf.length;
return ptr;
}}
",
debug
));
Ok(())
}
fn expose_pass_array8_to_wasm(&mut self) -> Result<(), Error> {
self.expose_uint8_memory();
self.pass_array_to_wasm("passArray8ToWasm", "getUint8Memory", 1)
}
fn expose_pass_array16_to_wasm(&mut self) -> Result<(), Error> {
self.expose_uint16_memory();
self.pass_array_to_wasm("passArray16ToWasm", "getUint16Memory", 2)
}
fn expose_pass_array32_to_wasm(&mut self) -> Result<(), Error> {
self.expose_uint32_memory();
self.pass_array_to_wasm("passArray32ToWasm", "getUint32Memory", 4)
}
fn expose_pass_array64_to_wasm(&mut self) -> Result<(), Error> {
self.expose_uint64_memory();
self.pass_array_to_wasm("passArray64ToWasm", "getUint64Memory", 8)
}
fn expose_pass_array_f32_to_wasm(&mut self) -> Result<(), Error> {
self.expose_f32_memory();
self.pass_array_to_wasm("passArrayF32ToWasm", "getFloat32Memory", 4)
}
fn expose_pass_array_f64_to_wasm(&mut self) -> Result<(), Error> {
self.expose_f64_memory();
self.pass_array_to_wasm("passArrayF64ToWasm", "getFloat64Memory", 8)
}
fn expose_pass_array_jsvalue_to_wasm(&mut self) -> Result<(), Error> {
if !self.should_write_global("pass_array_jsvalue") {
return Ok(());
}
self.require_internal_export("__wbindgen_malloc")?;
self.expose_uint32_memory();
self.expose_add_heap_object();
self.global(
"
function passArrayJsValueToWasm(array) {
const ptr = wasm.__wbindgen_malloc(array.length * 4);
const mem = getUint32Memory();
for (let i = 0; i < array.length; i++) {
mem[ptr / 4 + i] = addHeapObject(array[i]);
}
WASM_VECTOR_LEN = array.length;
return ptr;
}
",
);
Ok(())
}
fn pass_array_to_wasm(
&mut self,
name: &'static str,
delegate: &str,
size: usize,
) -> Result<(), Error> {
if !self.should_write_global(name) {
return Ok(());
}
self.require_internal_export("__wbindgen_malloc")?;
self.expose_wasm_vector_len();
self.global(&format!(
"
function {}(arg) {{
const ptr = wasm.__wbindgen_malloc(arg.length * {size});
{}().set(arg, ptr / {size});
WASM_VECTOR_LEN = arg.length;
return ptr;
}}
",
name,
delegate,
size = size
));
Ok(())
}
fn expose_text_encoder(&mut self) {
if !self.should_write_global("text_encoder") {
return;
}
self.expose_text_processor("TextEncoder");
}
fn expose_text_decoder(&mut self) {
if !self.should_write_global("text_decoder") {
return;
}
self.expose_text_processor("TextDecoder");
}
fn expose_text_processor(&mut self, s: &str) {
if self.config.nodejs_experimental_modules {
self.imports
.push_str(&format!("import {{ {} }} from 'util';\n", s));
self.global(&format!("let cached{0} = new {0}('utf-8');", s));
} else if self.config.nodejs {
self.global(&format!("const {0} = require('util').{0};", s));
self.global(&format!("let cached{0} = new {0}('utf-8');", s));
} else if !(self.config.browser || self.config.no_modules) {
self.global(&format!(
"
const l{0} = typeof {0} === 'undefined' ? \
require('util').{0} : {0};\
",
s
));
self.global(&format!("let cached{0} = new l{0}('utf-8');", s));
} else {
self.global(&format!("let cached{0} = new {0}('utf-8');", s));
}
}
fn expose_get_string_from_wasm(&mut self) {
if !self.should_write_global("get_string_from_wasm") {
return;
}
self.expose_text_decoder();
self.expose_uint8_memory();
// Typically we try to give a raw view of memory out to `TextDecoder` to
// avoid copying too much data. If, however, a `SharedArrayBuffer` is
// being used it looks like that is rejected by `TextDecoder` or
// otherwise doesn't work with it. When we detect a shared situation we
// use `slice` which creates a new array instead of `subarray` which
// creates just a view. That way in shared mode we copy more data but in
// non-shared mode there's no need to copy the data except for the
// string itself.
self.memory(); // set self.memory_init
let is_shared = self
.module
.memory_section()
.map(|s| s.entries()[0].limits().shared())
.unwrap_or(match &self.memory_init {
Some(limits) => limits.shared(),
None => false,
});
let method = if is_shared { "slice" } else { "subarray" };
self.global(&format!(
"
function getStringFromWasm(ptr, len) {{
return cachedTextDecoder.decode(getUint8Memory().{}(ptr, ptr + len));
}}
",
method
));
}
fn expose_get_array_js_value_from_wasm(&mut self) {
if !self.should_write_global("get_array_js_value_from_wasm") {
return;
}
self.expose_uint32_memory();
self.expose_take_object();
self.global(
"
function getArrayJsValueFromWasm(ptr, len) {
const mem = getUint32Memory();
const slice = mem.subarray(ptr / 4, ptr / 4 + len);
const result = [];
for (let i = 0; i < slice.length; i++) {
result.push(takeObject(slice[i]));
}
return result;
}
",
);
}
fn expose_get_array_i8_from_wasm(&mut self) {
self.expose_int8_memory();
self.arrayget("getArrayI8FromWasm", "getInt8Memory", 1);
}
fn expose_get_array_u8_from_wasm(&mut self) {
self.expose_uint8_memory();
self.arrayget("getArrayU8FromWasm", "getUint8Memory", 1);
}
fn expose_get_clamped_array_u8_from_wasm(&mut self) {
self.expose_clamped_uint8_memory();
self.arrayget("getClampedArrayU8FromWasm", "getUint8ClampedMemory", 1);
}
fn expose_get_array_i16_from_wasm(&mut self) {
self.expose_int16_memory();
self.arrayget("getArrayI16FromWasm", "getInt16Memory", 2);
}
fn expose_get_array_u16_from_wasm(&mut self) {
self.expose_uint16_memory();
self.arrayget("getArrayU16FromWasm", "getUint16Memory", 2);
}
fn expose_get_array_i32_from_wasm(&mut self) {
self.expose_int32_memory();
self.arrayget("getArrayI32FromWasm", "getInt32Memory", 4);
}
fn expose_get_array_u32_from_wasm(&mut self) {
self.expose_uint32_memory();
self.arrayget("getArrayU32FromWasm", "getUint32Memory", 4);
}
fn expose_get_array_i64_from_wasm(&mut self) {
self.expose_int64_memory();
self.arrayget("getArrayI64FromWasm", "getInt64Memory", 8);
}
fn expose_get_array_u64_from_wasm(&mut self) {
self.expose_uint64_memory();
self.arrayget("getArrayU64FromWasm", "getUint64Memory", 8);
}
fn expose_get_array_f32_from_wasm(&mut self) {
self.expose_f32_memory();
self.arrayget("getArrayF32FromWasm", "getFloat32Memory", 4);
}
fn expose_get_array_f64_from_wasm(&mut self) {
self.expose_f64_memory();
self.arrayget("getArrayF64FromWasm", "getFloat64Memory", 8);
}
fn arrayget(&mut self, name: &'static str, mem: &'static str, size: usize) {
if !self.should_write_global(name) {
return;
}
self.global(&format!(
"
function {name}(ptr, len) {{
return {mem}().subarray(ptr / {size}, ptr / {size} + len);
}}
",
name = name,
mem = mem,
size = size,
));
}
fn expose_int8_memory(&mut self) {
self.memview("getInt8Memory", "Int8Array");
}
fn expose_uint8_memory(&mut self) {
self.memview("getUint8Memory", "Uint8Array");
}
fn expose_clamped_uint8_memory(&mut self) {
self.memview("getUint8ClampedMemory", "Uint8ClampedArray");
}
fn expose_int16_memory(&mut self) {
self.memview("getInt16Memory", "Int16Array");
}
fn expose_uint16_memory(&mut self) {
self.memview("getUint16Memory", "Uint16Array");
}
fn expose_int32_memory(&mut self) {
self.memview("getInt32Memory", "Int32Array");
}
fn expose_uint32_memory(&mut self) {
self.memview("getUint32Memory", "Uint32Array");
}
fn expose_int64_memory(&mut self) {
self.memview("getInt64Memory", "BigInt64Array");
}
fn expose_uint64_memory(&mut self) {
self.memview("getUint64Memory", "BigUint64Array");
}
fn expose_f32_memory(&mut self) {
self.memview("getFloat32Memory", "Float32Array");
}
fn expose_f64_memory(&mut self) {
self.memview("getFloat64Memory", "Float64Array");
}
fn memview_function(&mut self, t: VectorKind) -> &'static str {
match t {
VectorKind::String => {
self.expose_uint8_memory();
"getUint8Memory"
}
VectorKind::I8 => {
self.expose_int8_memory();
"getInt8Memory"
}
VectorKind::U8 => {
self.expose_uint8_memory();
"getUint8Memory"
}
VectorKind::ClampedU8 => {
self.expose_clamped_uint8_memory();
"getUint8ClampedMemory"
}
VectorKind::I16 => {
self.expose_int16_memory();
"getInt16Memory"
}
VectorKind::U16 => {
self.expose_uint16_memory();
"getUint16Memory"
}
VectorKind::I32 => {
self.expose_int32_memory();
"getInt32Memory"
}
VectorKind::U32 => {
self.expose_uint32_memory();
"getUint32Memory"
}
VectorKind::I64 => {
self.expose_int64_memory();
"getInt64Memory"
}
VectorKind::U64 => {
self.expose_uint64_memory();
"getUint64Memory"
}
VectorKind::F32 => {
self.expose_f32_memory();
"getFloat32Memory"
}
VectorKind::F64 => {
self.expose_f64_memory();
"getFloat64Memory"
}
VectorKind::Anyref => {
self.expose_uint32_memory();
"getUint32Memory"
}
}
}
fn memview(&mut self, name: &'static str, js: &str) {
if !self.should_write_global(name) {
return;
}
let mem = self.memory();
self.global(&format!(
"
let cache{name} = null;
function {name}() {{
if (cache{name} === null || cache{name}.buffer !== {mem}.buffer) {{
cache{name} = new {js}({mem}.buffer);
}}
return cache{name};
}}
",
name = name,
js = js,
mem = mem,
));
}
fn expose_assert_class(&mut self) {
if !self.should_write_global("assert_class") {
return;
}
self.global(
"
function _assertClass(instance, klass) {
if (!(instance instanceof klass)) {
throw new Error(`expected instance of ${klass.name}`);
}
return instance.ptr;
}
",
);
}
fn expose_global_stack_pointer(&mut self) {
if !self.should_write_global("stack_pointer") {
return;
}
self.global(&format!("let stack_pointer = {};", INITIAL_HEAP_OFFSET));
}
fn expose_borrowed_objects(&mut self) {
if !self.should_write_global("borrowed_objects") {
return;
}
self.expose_global_heap();
self.expose_global_stack_pointer();
// Our `stack_pointer` points to where we should start writing stack
// objects, and the `stack_pointer` is incremented in a `finally` block
// after executing this. Once we've reserved stack space we write the
// value. Eventually underflow will throw an exception, but JS sort of
// just handles it today...
self.global(
"
function addBorrowedObject(obj) {
if (stack_pointer == 1) throw new Error('out of js stack');
heap[--stack_pointer] = obj;
return stack_pointer;
}
",
);
}
fn expose_take_object(&mut self) {
if !self.should_write_global("take_object") {
return;
}
self.expose_get_object();
self.expose_drop_ref();
self.global(
"
function takeObject(idx) {
const ret = getObject(idx);
dropObject(idx);
return ret;
}
",
);
}
fn expose_add_heap_object(&mut self) {
if !self.should_write_global("add_heap_object") {
return;
}
self.expose_global_heap();
self.expose_global_heap_next();
let set_heap_next = if self.config.debug {
String::from(
"
if (typeof(heap_next) !== 'number') throw new Error('corrupt heap');
",
)
} else {
String::new()
};
// Allocating a slot on the heap first goes through the linked list
// (starting at `heap_next`). Once that linked list is exhausted we'll
// be pointing beyond the end of the array, at which point we'll reserve
// one more slot and use that.
self.global(&format!(
"
function addHeapObject(obj) {{
if (heap_next === heap.length) heap.push(heap.length + 1);
const idx = heap_next;
heap_next = heap[idx];
{}
heap[idx] = obj;
return idx;
}}
",
set_heap_next
));
}
fn wasm_import_needed(&self, name: &str) -> bool {
let imports = match self.module.import_section() {
Some(s) => s,
None => return false,
};
imports
.entries()
.iter()
.any(|i| i.module() == "__wbindgen_placeholder__" && i.field() == name)
}
fn pass_to_wasm_function(&mut self, t: VectorKind) -> Result<&'static str, Error> {
let s = match t {
VectorKind::String => {
self.expose_pass_string_to_wasm()?;
"passStringToWasm"
}
VectorKind::I8 | VectorKind::U8 | VectorKind::ClampedU8 => {
self.expose_pass_array8_to_wasm()?;
"passArray8ToWasm"
}
VectorKind::U16 | VectorKind::I16 => {
self.expose_pass_array16_to_wasm()?;
"passArray16ToWasm"
}
VectorKind::I32 | VectorKind::U32 => {
self.expose_pass_array32_to_wasm()?;
"passArray32ToWasm"
}
VectorKind::I64 | VectorKind::U64 => {
self.expose_pass_array64_to_wasm()?;
"passArray64ToWasm"
}
VectorKind::F32 => {
self.expose_pass_array_f32_to_wasm()?;
"passArrayF32ToWasm"
}
VectorKind::F64 => {
self.expose_pass_array_f64_to_wasm()?;
"passArrayF64ToWasm"
}
VectorKind::Anyref => {
self.expose_pass_array_jsvalue_to_wasm()?;
"passArrayJsValueToWasm"
}
};
Ok(s)
}
fn expose_get_vector_from_wasm(&mut self, ty: VectorKind) -> &'static str {
match ty {
VectorKind::String => {
self.expose_get_string_from_wasm();
"getStringFromWasm"
}
VectorKind::I8 => {
self.expose_get_array_i8_from_wasm();
"getArrayI8FromWasm"
}
VectorKind::U8 => {
self.expose_get_array_u8_from_wasm();
"getArrayU8FromWasm"
}
VectorKind::ClampedU8 => {
self.expose_get_clamped_array_u8_from_wasm();
"getClampedArrayU8FromWasm"
}
VectorKind::I16 => {
self.expose_get_array_i16_from_wasm();
"getArrayI16FromWasm"
}
VectorKind::U16 => {
self.expose_get_array_u16_from_wasm();
"getArrayU16FromWasm"
}
VectorKind::I32 => {
self.expose_get_array_i32_from_wasm();
"getArrayI32FromWasm"
}
VectorKind::U32 => {
self.expose_get_array_u32_from_wasm();
"getArrayU32FromWasm"
}
VectorKind::I64 => {
self.expose_get_array_i64_from_wasm();
"getArrayI64FromWasm"
}
VectorKind::U64 => {
self.expose_get_array_u64_from_wasm();
"getArrayU64FromWasm"
}
VectorKind::F32 => {
self.expose_get_array_f32_from_wasm();
"getArrayF32FromWasm"
}
VectorKind::F64 => {
self.expose_get_array_f64_from_wasm();
"getArrayF64FromWasm"
}
VectorKind::Anyref => {
self.expose_get_array_js_value_from_wasm();
"getArrayJsValueFromWasm"
}
}
}
fn expose_global_argument_ptr(&mut self) -> Result<(), Error> {
if !self.should_write_global("global_argument_ptr") {
return Ok(());
}
self.require_internal_export("__wbindgen_global_argument_ptr")?;
self.global(
"
let cachedGlobalArgumentPtr = null;
function globalArgumentPtr() {
if (cachedGlobalArgumentPtr === null) {
cachedGlobalArgumentPtr = wasm.__wbindgen_global_argument_ptr();
}
return cachedGlobalArgumentPtr;
}
",
);
Ok(())
}
fn expose_get_inherited_descriptor(&mut self) {
if !self.should_write_global("get_inherited_descriptor") {
return;
}
// It looks like while rare some browsers will move descriptors up the
// property chain which runs the risk of breaking wasm-bindgen-generated
// code because we're looking for precise descriptor functions rather
// than relying on the prototype chain like most "normal JS" projects
// do.
//
// As a result we have a small helper here which will walk the prototype
// chain looking for a descriptor. For some more information on this see
// #109
self.global(
"
function GetOwnOrInheritedPropertyDescriptor(obj, id) {
while (obj) {
let desc = Object.getOwnPropertyDescriptor(obj, id);
if (desc) return desc;
obj = Object.getPrototypeOf(obj);
}
return {}
}
",
);
}
fn expose_u32_cvt_shim(&mut self) -> &'static str {
let name = "u32CvtShim";
if !self.should_write_global(name) {
return name;
}
self.global(&format!("const {} = new Uint32Array(2);", name));
name
}
fn expose_int64_cvt_shim(&mut self) -> &'static str {
let name = "int64CvtShim";
if !self.should_write_global(name) {
return name;
}
let n = self.expose_u32_cvt_shim();
self.global(&format!(
"const {} = new BigInt64Array({}.buffer);",
name, n
));
name
}
fn expose_uint64_cvt_shim(&mut self) -> &'static str {
let name = "uint64CvtShim";
if !self.should_write_global(name) {
return name;
}
let n = self.expose_u32_cvt_shim();
self.global(&format!(
"const {} = new BigUint64Array({}.buffer);",
name, n
));
name
}
fn expose_is_like_none(&mut self) {
if !self.should_write_global("is_like_none") {
return;
}
self.global(
"
function isLikeNone(x) {
return x === undefined || x === null;
}
",
);
}
fn expose_cleanup_groups(&mut self) {
if !self.should_write_global("cleanup_groups") {
return;
}
self.global(
"
const CLEANUPS = new WeakRefGroup(x => x.holdings());
const CLEANUPS_MAP = new Map();
function addCleanup(obj, ptr, free) {
const ref = CLEANUPS.makeRef(obj, () => free(ptr));
CLEANUPS_MAP.set(ptr, ref);
}
",
);
}
fn gc(&mut self) {
gc::Config::new()
.demangle(self.config.demangle)
.keep_debug(self.config.keep_debug || self.config.debug)
.run(&mut self.module);
}
pub fn parse_wasm_names(&mut self) {
let module = mem::replace(self.module, Module::default());
let module = module.parse_names().unwrap_or_else(|p| p.1);
*self.module = module;
if self.config.remove_name_section {
self.module.sections_mut().retain(|s| match s {
Section::Name(_) => false,
_ => true,
});
}
}
fn describe(&mut self, name: &str) -> Option<Descriptor> {
let name = format!("__wbindgen_describe_{}", name);
let descriptor = self.interpreter.interpret_descriptor(&name, self.module)?;
Some(Descriptor::decode(descriptor))
}
fn global(&mut self, s: &str) {
let s = s.trim();
// Ensure a blank line between adjacent items, and ensure everything is
// terminated with a newline.
while !self.globals.ends_with("\n\n\n") && !self.globals.ends_with("*/\n") {
self.globals.push_str("\n");
}
self.globals.push_str(s);
self.globals.push_str("\n");
}
fn use_node_require(&self) -> bool {
self.config.nodejs && !self.config.nodejs_experimental_modules
}
fn memory(&mut self) -> &'static str {
if self.module.memory_section().is_some() {
return "wasm.memory";
}
let (entry, mem) = self
.module
.import_section()
.expect("must import memory")
.entries()
.iter()
.filter_map(|i| match i.external() {
External::Memory(m) => Some((i, m)),
_ => None,
})
.next()
.expect("must import memory");
assert_eq!(entry.field(), "memory");
self.memory_init = Some(mem.limits().clone());
"memory"
}
fn require_class_wrap(&mut self, class: &str) {
self.exported_classes
.as_mut()
.expect("classes already written")
.entry(class.to_string())
.or_insert_with(ExportedClass::default)
.wrap_needed = true;
}
fn import_identifier(&mut self, import: Import<'a>) -> String {
// Here's where it's a bit tricky. We need to make sure that importing
// the same identifier from two different modules works, and they're
// named uniquely below. Additionally if we've already imported the same
// identifier from the module in question then we'd like to reuse the
// one that was previously imported.
//
// Our `imported_names` map keeps track of all imported identifiers from
// modules, mapping the imported names onto names actually available for
// use in our own module. If our identifier isn't present then we
// generate a new identifier and are sure to generate the appropriate JS
// import for our new identifier.
let use_node_require = self.use_node_require();
let imported_identifiers = &mut self.imported_identifiers;
let imports = &mut self.imports;
let imports_post = &mut self.imports_post;
let identifier = self
.imported_names
.entry(import.module())
.or_insert_with(Default::default)
.entry(import.name())
.or_insert_with(|| {
let name = generate_identifier(import.name(), imported_identifiers);
match &import {
Import::Module { module, .. } => {
if use_node_require {
imports.push_str(&format!(
"const {} = require(String.raw`{}`).{};\n",
name,
module,
import.name()
));
} else if import.name() == name {
imports
.push_str(&format!("import {{ {} }} from '{}';\n", name, module));
} else {
imports.push_str(&format!(
"import {{ {} as {} }} from '{}';\n",
import.name(),
name,
module
));
}
name
}
Import::VendorPrefixed { prefixes, .. } => {
imports_post.push_str("const l");
imports_post.push_str(&name);
imports_post.push_str(" = ");
switch(imports_post, &name, "", prefixes);
imports_post.push_str(";\n");
fn switch(dst: &mut String, name: &str, prefix: &str, left: &[&str]) {
if left.len() == 0 {
dst.push_str(prefix);
return dst.push_str(name);
}
dst.push_str("(typeof ");
dst.push_str(prefix);
dst.push_str(name);
dst.push_str(" == 'undefined' ? ");
match left.len() {
1 => {
dst.push_str(&left[0]);
dst.push_str(name);
}
_ => switch(dst, name, &left[0], &left[1..]),
}
dst.push_str(" : ");
dst.push_str(prefix);
dst.push_str(name);
dst.push_str(")");
}
format!("l{}", name)
}
Import::Global { .. } => name,
}
});
// If there's a namespace we didn't actually import `item` but rather
// the namespace, so access through that.
match import.field() {
Some(field) => format!("{}.{}", identifier, field),
None => identifier.clone(),
}
}
fn generated_import_target(
&mut self,
name: Import<'a>,
import: &decode::ImportFunction<'a>,
) -> Result<ImportTarget, Error> {
let method_data = match &import.method {
Some(data) => data,
None => {
let name = self.import_identifier(name);
if import.structural || !name.contains(".") {
return Ok(ImportTarget::Function(name));
}
self.global(&format!("const {}_target = {};", import.shim, name));
let target = format!("{}_target", import.shim);
return Ok(ImportTarget::Function(target));
}
};
let class = self.import_identifier(name);
let op = match &method_data.kind {
decode::MethodKind::Constructor => {
return Ok(ImportTarget::Constructor(class.to_string()));
}
decode::MethodKind::Operation(op) => op,
};
if import.structural {
let class = if op.is_static {
Some(class.clone())
} else {
None
};
return Ok(match &op.kind {
decode::OperationKind::Regular => {
let name = import.function.name.to_string();
match class {
Some(c) => ImportTarget::Function(format!("{}.{}", c, name)),
None => ImportTarget::StructuralMethod(name),
}
}
decode::OperationKind::Getter(g) => {
ImportTarget::StructuralGetter(class, g.to_string())
}
decode::OperationKind::Setter(s) => {
ImportTarget::StructuralSetter(class, s.to_string())
}
decode::OperationKind::IndexingGetter => {
ImportTarget::StructuralIndexingGetter(class)
}
decode::OperationKind::IndexingSetter => {
ImportTarget::StructuralIndexingSetter(class)
}
decode::OperationKind::IndexingDeleter => {
ImportTarget::StructuralIndexingDeleter(class)
}
});
}
let target = format!(
"typeof {0} === 'undefined' ? null : {}{}",
class,
if op.is_static { "" } else { ".prototype" }
);
let (mut target, name) = match &op.kind {
decode::OperationKind::Regular => (
format!("{}.{}", target, import.function.name),
&import.function.name,
),
decode::OperationKind::Getter(g) => {
self.expose_get_inherited_descriptor();
(
format!(
"GetOwnOrInheritedPropertyDescriptor({}, '{}').get",
target, g,
),
g,
)
}
decode::OperationKind::Setter(s) => {
self.expose_get_inherited_descriptor();
(
format!(
"GetOwnOrInheritedPropertyDescriptor({}, '{}').set",
target, s,
),
s,
)
}
decode::OperationKind::IndexingGetter => panic!("indexing getter should be structural"),
decode::OperationKind::IndexingSetter => panic!("indexing setter should be structural"),
decode::OperationKind::IndexingDeleter => {
panic!("indexing deleter should be structural")
}
};
target.push_str(&format!(
" || function() {{
throw new Error(`wasm-bindgen: {}.{} does not exist`);
}}",
class, name
));
if op.is_static {
target.insert(0, '(');
target.push_str(").bind(");
target.push_str(&class);
target.push_str(")");
}
self.global(&format!("const {}_target = {};", import.shim, target));
Ok(if op.is_static {
ImportTarget::Function(format!("{}_target", import.shim))
} else {
ImportTarget::Method(format!("{}_target", import.shim))
})
}
/// Update the wasm file's `producers` section to include information about
/// the wasm-bindgen tool.
///
/// Specified at:
/// https://github.com/WebAssembly/tool-conventions/blob/master/ProducersSection.md
fn update_producers_section(&mut self) {
for section in self.module.sections_mut() {
let section = match section {
Section::Custom(s) => s,
_ => continue,
};
if section.name() != "producers" {
return;
}
drop(update(section));
return;
}
// `CustomSection::new` added in paritytech/parity-wasm#244 which isn't
// merged just yet
let data = [
("producers".len() + 2) as u8,
"producers".len() as u8,
b'p',
b'r',
b'o',
b'd',
b'u',
b'c',
b'e',
b'r',
b's',
0,
];
let mut section = CustomSection::deserialize(&mut &data[..]).unwrap();
assert_eq!(section.name(), "producers");
assert_eq!(section.payload(), [0]);
drop(update(&mut section));
self.module.sections_mut().push(Section::Custom(section));
fn update(section: &mut CustomSection) -> Result<(), ParityError> {
struct Field {
name: String,
values: Vec<FieldValue>,
}
struct FieldValue {
name: String,
version: String,
}
let wasm_bindgen = || FieldValue {
name: "wasm-bindgen".to_string(),
version: shared::version(),
};
let mut fields = Vec::new();
// Deserialize the fields, appending the wasm-bidngen field/value
// where applicable
{
let mut data = section.payload();
let amt: u32 = VarUint32::deserialize(&mut data)?.into();
let mut found_processed_by = false;
for _ in 0..amt {
let name = String::deserialize(&mut data)?;
let cnt: u32 = VarUint32::deserialize(&mut data)?.into();
let mut values = Vec::with_capacity(cnt as usize);
for _ in 0..cnt {
let name = String::deserialize(&mut data)?;
let version = String::deserialize(&mut data)?;
values.push(FieldValue { name, version });
}
if name == "processed-by" {
found_processed_by = true;
values.push(wasm_bindgen());
}
fields.push(Field { name, values });
}
if data.len() != 0 {
return Err(ParityError::InconsistentCode);
}
if !found_processed_by {
fields.push(Field {
name: "processed-by".to_string(),
values: vec![wasm_bindgen()],
});
}
}
// re-serialize these fields back into the custom section
let dst = section.payload_mut();
dst.truncate(0);
VarUint32::from(fields.len() as u32).serialize(dst)?;
for field in fields.iter() {
field.name.clone().serialize(dst)?;
VarUint32::from(field.values.len() as u32).serialize(dst)?;
for value in field.values.iter() {
value.name.clone().serialize(dst)?;
value.version.clone().serialize(dst)?;
}
}
Ok(())
}
}
fn add_start_function(&mut self) -> Result<(), Error> {
let start = match &self.start {
Some(name) => name.clone(),
None => return Ok(()),
};
let idx = {
let exports = self
.module
.export_section()
.ok_or_else(|| format_err!("no export section found"))?;
let entry = exports
.entries()
.iter()
.find(|e| e.field() == start)
.ok_or_else(|| format_err!("export `{}` not found", start))?;
match entry.internal() {
Internal::Function(i) => *i,
_ => bail!("export `{}` wasn't a function", start),
}
};
if let Some(prev_start) = self.module.start_section() {
if let Some(NameSection::Function(n)) = self.module.names_section() {
if let Some(prev) = n.names().get(prev_start) {
bail!(
"cannot flag `{}` as start function as `{}` is \
already the start function",
start,
prev
);
}
}
bail!(
"cannot flag `{}` as start function as another \
function is already the start function",
start
);
}
self.set_start_section(idx);
Ok(())
}
fn set_start_section(&mut self, start: u32) {
let mut pos = None;
// See http://webassembly.github.io/spec/core/binary/modules.html#binary-module
// for section ordering
for (i, section) in self.module.sections().iter().enumerate() {
match section {
Section::Type(_)
| Section::Import(_)
| Section::Function(_)
| Section::Table(_)
| Section::Memory(_)
| Section::Global(_)
| Section::Export(_) => continue,
_ => {
pos = Some(i);
break;
}
}
}
let pos = pos.unwrap_or(self.module.sections().len() - 1);
self.module
.sections_mut()
.insert(pos, Section::Start(start));
}
/// If a start function is present, it removes it from the `start` section
/// of the wasm module and then moves it to an exported function, named
/// `__wbindgen_start`.
fn unstart_start_function(&mut self) -> bool {
let mut pos = None;
let mut start = 0;
for (i, section) in self.module.sections().iter().enumerate() {
if let Section::Start(idx) = section {
start = *idx;
pos = Some(i);
break;
}
}
match pos {
Some(i) => {
self.module.sections_mut().remove(i);
let entry =
ExportEntry::new("__wbindgen_start".to_string(), Internal::Function(start));
self.module
.export_section_mut()
.unwrap()
.entries_mut()
.push(entry);
true
}
None => false,
}
}
/// Injects a `start` function into the wasm module. This start function
/// calls a shim in the generated JS which defers the actual start function
/// to the next microtask tick of the event queue.
///
/// See docs above at callsite for why this happens.
fn inject_start_shim(&mut self) {
let body = "function() {
Promise.resolve().then(() => wasm.__wbindgen_start());
}";
self.export("__wbindgen_defer_start", body, None);
let imports = self
.module
.import_section()
.map(|s| s.functions() as u32)
.unwrap_or(0);
Remap(|idx| if idx < imports { idx } else { idx + 1 }).remap_module(self.module);
let type_idx = {
let types = self.module.type_section_mut().unwrap();
let ty = Type::Function(FunctionType::new(Vec::new(), None));
types.types_mut().push(ty);
(types.types_mut().len() - 1) as u32
};
let entry = ImportEntry::new(
"__wbindgen_placeholder__".to_string(),
"__wbindgen_defer_start".to_string(),
External::Function(type_idx),
);
self.module
.import_section_mut()
.unwrap()
.entries_mut()
.push(entry);
self.set_start_section(imports);
}
}
impl<'a, 'b> SubContext<'a, 'b> {
pub fn generate(&mut self) -> Result<(), Error> {
for f in self.program.exports.iter() {
self.generate_export(f).with_context(|_| {
format!(
"failed to generate bindings for Rust export `{}`",
f.function.name
)
})?;
}
for f in self.program.imports.iter() {
if let decode::ImportKind::Type(ty) = &f.kind {
self.register_vendor_prefix(ty);
}
}
for f in self.program.imports.iter() {
self.generate_import(f)?;
}
for e in self.program.enums.iter() {
self.generate_enum(e);
}
for s in self.program.structs.iter() {
self.generate_struct(s).with_context(|_| {
format!("failed to generate bindings for Rust struct `{}`", s.name,)
})?;
}
for s in self.program.typescript_custom_sections.iter() {
self.cx.typescript.push_str(s);
self.cx.typescript.push_str("\n\n");
}
Ok(())
}
fn generate_export(&mut self, export: &decode::Export<'b>) -> Result<(), Error> {
if let Some(ref class) = export.class {
assert!(!export.start);
return self.generate_export_for_class(class, export);
}
let descriptor = match self.cx.describe(&export.function.name) {
None => return Ok(()),
Some(d) => d,
};
if export.start {
self.set_start_function(export.function.name)?;
}
let (js, ts, js_doc) = Js2Rust::new(&export.function.name, self.cx)
.process(descriptor.unwrap_function())?
.finish("function", &format!("wasm.{}", export.function.name));
self.cx.export(
&export.function.name,
&js,
Some(format_doc_comments(&export.comments, Some(js_doc))),
);
self.cx.globals.push_str("\n");
self.cx.typescript.push_str("export ");
self.cx.typescript.push_str(&ts);
self.cx.typescript.push_str("\n");
Ok(())
}
fn set_start_function(&mut self, start: &str) -> Result<(), Error> {
if let Some(prev) = &self.cx.start {
bail!(
"cannot flag `{}` as start function as `{}` is \
already the start function",
start,
prev
);
}
self.cx.start = Some(start.to_string());
Ok(())
}
fn generate_export_for_class(
&mut self,
class_name: &'b str,
export: &decode::Export,
) -> Result<(), Error> {
let wasm_name = shared::struct_function_export_name(class_name, &export.function.name);
let descriptor = match self.cx.describe(&wasm_name) {
None => return Ok(()),
Some(d) => d,
};
let function_name = if export.is_constructor {
"constructor"
} else {
&export.function.name
};
let (js, ts, js_doc) = Js2Rust::new(function_name, self.cx)
.method(export.method, export.consumed)
.constructor(if export.is_constructor {
Some(class_name)
} else {
None
})
.process(descriptor.unwrap_function())?
.finish("", &format!("wasm.{}", wasm_name));
let class = self
.cx
.exported_classes
.as_mut()
.expect("classes already written")
.entry(class_name.to_string())
.or_insert(ExportedClass::default());
class
.contents
.push_str(&format_doc_comments(&export.comments, Some(js_doc)));
class.typescript.push_str(" "); // Indentation
if export.is_constructor {
if class.has_constructor {
bail!("found duplicate constructor `{}`", export.function.name);
}
class.has_constructor = true;
} else if !export.method {
class.contents.push_str("static ");
class.typescript.push_str("static ");
}
class.contents.push_str(function_name);
class.contents.push_str(&js);
class.contents.push_str("\n");
class.typescript.push_str(&ts);
class.typescript.push_str("\n");
Ok(())
}
fn generate_import(&mut self, import: &decode::Import<'b>) -> Result<(), Error> {
match import.kind {
decode::ImportKind::Function(ref f) => {
self.generate_import_function(import, f).with_context(|_| {
format!(
"failed to generate bindings for JS import `{}`",
f.function.name
)
})?;
}
decode::ImportKind::Static(ref s) => {
self.generate_import_static(import, s).with_context(|_| {
format!("failed to generate bindings for JS import `{}`", s.name)
})?;
}
decode::ImportKind::Type(ref ty) => {
self.generate_import_type(import, ty).with_context(|_| {
format!("failed to generate bindings for JS import `{}`", ty.name,)
})?;
}
decode::ImportKind::Enum(_) => {}
}
Ok(())
}
fn generate_import_static(
&mut self,
info: &decode::Import<'b>,
import: &decode::ImportStatic<'b>,
) -> Result<(), Error> {
// The same static can be imported in multiple locations, so only
// generate bindings once for it.
if !self.cx.imported_statics.insert(import.shim) {
return Ok(());
}
// TODO: should support more types to import here
let obj = self.import_name(info, &import.name)?;
self.cx.expose_add_heap_object();
self.cx.export(
&import.shim,
&format!(
"
function() {{
return addHeapObject({});
}}
",
obj
),
None,
);
Ok(())
}
fn generate_import_function(
&mut self,
info: &decode::Import<'b>,
import: &decode::ImportFunction<'b>,
) -> Result<(), Error> {
if !self.cx.wasm_import_needed(&import.shim) {
return Ok(());
}
// It's possible for the same function to be imported in two locations,
// but we only want to generate one.
if !self.cx.imported_functions.insert(import.shim) {
return Ok(());
}
let descriptor = match self.cx.describe(&import.shim) {
None => return Ok(()),
Some(d) => d,
};
// Figure out the name that we're importing to dangle further references
// off of. This is the function name if there's no method all here, or
// the class if there's a method call.
let name = match &import.method {
Some(data) => self.determine_import(info, &data.class)?,
None => self.determine_import(info, &import.function.name)?,
};
// Build up our shim's state, and we'll use that to guide whether we
// actually emit an import here or not.
let mut shim = Rust2Js::new(self.cx);
if shim.cx.config.debug {
shim.catch_and_rethrow(true);
}
shim.catch(import.catch)
.variadic(import.variadic)
.process(descriptor.unwrap_function())?;
// If this is a bare function import and the shim doesn't actually do
// anything (all argument/return conversions are noops) then we can wire
// up the wasm import directly to the destination. We don't actually
// wire up anything here, but we record it to get wired up later.
if import.method.is_none() && shim.is_noop() {
if let Import::Module {
module,
name,
field: None,
} = name
{
shim.cx.direct_imports.insert(import.shim, (module, name));
return Ok(());
}
}
// If the above optimization fails then we actually generate the import
// here (possibly emitting some glue in our JS module) and then emit the
// shim as the wasm will be importing the shim.
let target = shim.cx.generated_import_target(name, import)?;
let js = shim.finish(&target)?;
shim.cx.export(&import.shim, &js, None);
Ok(())
}
fn generate_import_type(
&mut self,
info: &decode::Import<'b>,
import: &decode::ImportType<'b>,
) -> Result<(), Error> {
if !self.cx.wasm_import_needed(&import.instanceof_shim) {
return Ok(());
}
let name = self.import_name(info, &import.name)?;
self.cx.expose_get_object();
let body = format!(
"
function(idx) {{
return getObject(idx) instanceof {} ? 1 : 0;
}}
",
name,
);
self.cx.export(&import.instanceof_shim, &body, None);
Ok(())
}
fn generate_enum(&mut self, enum_: &decode::Enum) {
let mut variants = String::new();
for variant in enum_.variants.iter() {
variants.push_str(&format!("{}:{},", variant.name, variant.value));
}
self.cx.export(
&enum_.name,
&format!("Object.freeze({{ {} }})", variants),
Some(format_doc_comments(&enum_.comments, None)),
);
self.cx
.typescript
.push_str(&format!("export enum {} {{", enum_.name));
variants.clear();
for variant in enum_.variants.iter() {
variants.push_str(&format!("{},", variant.name));
}
self.cx.typescript.push_str(&variants);
self.cx.typescript.push_str("}\n");
}
fn generate_struct(&mut self, struct_: &decode::Struct) -> Result<(), Error> {
let mut dst = String::new();
let mut ts_dst = String::new();
for field in struct_.fields.iter() {
let wasm_getter = shared::struct_field_get(&struct_.name, &field.name);
let wasm_setter = shared::struct_field_set(&struct_.name, &field.name);
let descriptor = match self.cx.describe(&wasm_getter) {
None => continue,
Some(d) => d,
};
let set = {
let mut cx = Js2Rust::new(&field.name, self.cx);
cx.method(true, false)
.argument(&descriptor)?
.ret(&Descriptor::Unit)?;
ts_dst.push_str(&format!(
" {}{}: {};\n",
if field.readonly { "readonly " } else { "" },
field.name,
&cx.js_arguments[0].1
));
cx.finish("", &format!("wasm.{}", wasm_setter)).0
};
let (get, _ts, js_doc) = Js2Rust::new(&field.name, self.cx)
.method(true, false)
.ret(&descriptor)?
.finish("", &format!("wasm.{}", wasm_getter));
if !dst.ends_with("\n") {
dst.push_str("\n");
}
dst.push_str(&format_doc_comments(&field.comments, Some(js_doc)));
dst.push_str("get ");
dst.push_str(&field.name);
dst.push_str(&get);
dst.push_str("\n");
if !field.readonly {
dst.push_str("set ");
dst.push_str(&field.name);
dst.push_str(&set);
}
}
let class = self
.cx
.exported_classes
.as_mut()
.expect("classes already written")
.entry(struct_.name.to_string())
.or_insert_with(Default::default);
class.comments = format_doc_comments(&struct_.comments, None);
class.contents.push_str(&dst);
class.contents.push_str("\n");
class.typescript.push_str(&ts_dst);
class.typescript.push_str("\n");
Ok(())
}
fn register_vendor_prefix(&mut self, info: &decode::ImportType<'b>) {
if info.vendor_prefixes.len() == 0 {
return;
}
self.vendor_prefixes
.entry(info.name)
.or_insert(Vec::new())
.extend(info.vendor_prefixes.iter().cloned());
}
fn determine_import(
&self,
import: &decode::Import<'b>,
item: &'b str,
) -> Result<Import<'b>, Error> {
// First up, imports don't work at all in `--no-modules` mode as we're
// not sure how to import them.
if self.cx.config.no_modules {
if let Some(module) = &import.module {
bail!(
"import from `{}` module not allowed with `--no-modules`; \
use `--nodejs` or `--browser` instead",
module
);
}
}
// Similar to `--no-modules`, only allow vendor prefixes basically for web
// apis, shouldn't be necessary for things like npm packages or other
// imported items.
let vendor_prefixes = self.vendor_prefixes.get(item);
if let Some(vendor_prefixes) = vendor_prefixes {
assert!(vendor_prefixes.len() > 0);
if let Some(module) = &import.module {
bail!(
"import of `{}` from `{}` has a polyfill of `{}` listed, but
vendor prefixes aren't supported when importing from modules",
item,
module,
&vendor_prefixes[0],
);
}
if let Some(ns) = &import.js_namespace {
bail!(
"import of `{}` through js namespace `{}` isn't supported \
right now when it lists a polyfill",
item,
ns
);
}
return Ok(Import::VendorPrefixed {
name: item,
prefixes: vendor_prefixes.clone(),
});
}
let name = import.js_namespace.as_ref().map(|s| &**s).unwrap_or(item);
let field = if import.js_namespace.is_some() {
Some(item)
} else {
None
};
Ok(match import.module {
Some(module) => Import::Module {
module,
name,
field,
},
None => Import::Global { name, field },
})
}
fn import_name(&mut self, import: &decode::Import<'b>, item: &'b str) -> Result<String, Error> {
let import = self.determine_import(import, item)?;
Ok(self.cx.import_identifier(import))
}
}
impl<'a> Import<'a> {
fn module(&self) -> Option<&'a str> {
match self {
Import::Module { module, .. } => Some(module),
_ => None,
}
}
fn field(&self) -> Option<&'a str> {
match self {
Import::Module { field, .. } | Import::Global { field, .. } => *field,
Import::VendorPrefixed { .. } => None,
}
}
fn name(&self) -> &'a str {
match self {
Import::Module { name, .. }
| Import::Global { name, .. }
| Import::VendorPrefixed { name, .. } => *name,
}
}
}
fn generate_identifier(name: &str, used_names: &mut HashMap<String, usize>) -> String {
let cnt = used_names.entry(name.to_string()).or_insert(0);
*cnt += 1;
// We want to mangle `default` at once, so we can support default exports and don't generate
// invalid glue code like this: `import { default } from './module';`.
if *cnt == 1 && name != "default" {
name.to_string()
} else {
format!("{}{}", name, cnt)
}
}
fn format_doc_comments(comments: &[&str], js_doc_comments: Option<String>) -> String {
let body: String = comments
.iter()
.map(|c| format!("*{}\n", c.trim_matches('"')))
.collect();
let doc = if let Some(docs) = js_doc_comments {
docs.lines().map(|l| format!("* {} \n", l)).collect()
} else {
String::new()
};
format!("/**\n{}{}*/\n", body, doc)
}
#[test]
fn test_generate_identifier() {
let mut used_names: HashMap<String, usize> = HashMap::new();
assert_eq!(
generate_identifier("someVar", &mut used_names),
"someVar".to_string()
);
assert_eq!(
generate_identifier("someVar", &mut used_names),
"someVar2".to_string()
);
assert_eq!(
generate_identifier("default", &mut used_names),
"default1".to_string()
);
assert_eq!(
generate_identifier("default", &mut used_names),
"default2".to_string()
);
}