makepad/libs/stitch/src/module.rs
2025-05-06 10:11:37 +02:00

1034 lines
35 KiB
Rust

use {
crate::{
code::UncompiledCode,
config,
const_expr::ConstExpr,
data::Data,
decode::{Decode, DecodeError, Decoder},
elem::{Elem, UnguardedElems},
engine::Engine,
error::Error,
extern_val::{ExternType, ExternTypeDesc, ExternVal, ExternValDesc},
func::{Func, FuncType},
global::{Global, GlobalType},
instance::{Instance, InstanceIniter},
linker::{InstantiateError, Linker},
mem::{Mem, MemType},
ref_::{Ref, RefType},
store::Store,
table::{Table, TableType},
trap::Trap,
val::ValType,
},
std::{
collections::{hash_map, HashMap, HashSet},
slice,
sync::Arc,
},
};
/// A Wasm module.
#[derive(Debug)]
pub struct Module {
types: Arc<[FuncType]>,
imports: Box<[((Arc<str>, Arc<str>), ImportKind)]>,
imported_func_count: usize,
imported_table_count: usize,
imported_memory_count: usize,
imported_global_count: usize,
func_types: Box<[FuncType]>,
table_types: Box<[TableType]>,
memory_types: Box<[MemType]>,
global_types: Box<[GlobalType]>,
global_vals: Box<[ConstExpr]>,
exports: HashMap<Arc<str>, ExternValDesc>,
start: Option<u32>,
codes: Box<[UncompiledCode]>,
elems: Box<[ElemDef]>,
datas: Box<[DataDef]>,
}
impl Module {
/// Decodes and validates a new [`Module`] from the given byte slice.
///
/// # Errors
///
/// - If the [`Module`] is malformed.
/// - If the [`Module`] is invalid.
pub fn new(engine: &Engine, bytes: &[u8]) -> Result<Module, DecodeError> {
const MAGIC: [u8; 4] = [0x00, 0x61, 0x73, 0x6D];
const VERSION: [u8; 4] = [0x01, 0x00, 0x00, 0x00];
const EXPECTED_SECTION_IDS: &[u8] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 10, 11];
let mut decoder = Decoder::new(bytes);
let magic = decoder.read_bytes(4)?;
if magic != MAGIC {
return Err(DecodeError::new(""))?;
}
let version = decoder.read_bytes(4)?;
if version != VERSION {
return Err(DecodeError::new(""))?;
}
let mut builder = ModuleBuilder::new();
let mut expected_section_ids = EXPECTED_SECTION_IDS.iter().copied();
while !decoder.is_at_end() {
let section_id = decoder.read_byte()?;
if section_id != 0 {
if !expected_section_ids
.any(|expected_section_id| expected_section_id == section_id)
{
return Err(DecodeError::new("section id mismatch"))?;
}
}
let mut section_decoder = decoder.decode_decoder()?;
match section_id {
// Custom section
0 => {
section_decoder.decode_string()?;
section_decoder.read_bytes_until_end();
}
// Type section
1 => {
for type_ in section_decoder.decode_iter()? {
builder.push_type(type_?)?;
}
}
// Import section
2 => {
for import in section_decoder.decode_iter()? {
builder.push_import(import?)?;
}
}
// Function section
3 => {
for type_idx in section_decoder.decode_iter()? {
builder.push_func(type_idx?)?;
}
}
// Table section
4 => {
for table in section_decoder.decode_iter()? {
builder.push_table(table?)?;
}
}
// Memory section
5 => {
for mem in section_decoder.decode_iter()? {
builder.push_memory(mem?)?;
}
}
// Global section
6 => {
for global in section_decoder.decode_iter()? {
builder.push_global(global?)?;
}
}
// Export section
7 => {
for export in section_decoder.decode_iter()? {
builder.push_export(export?)?;
}
}
// Start section
8 => {
builder.set_start(section_decoder.decode()?)?;
}
// Element section
9 => {
for elem in section_decoder.decode_iter()? {
builder.push_elem(elem?)?;
}
}
// Code section
10 => {
for code in section_decoder.decode_iter()? {
builder.push_code(code?)?;
}
}
// Data section
11 => {
for data in section_decoder.decode_iter()? {
builder.push_data(data?)?;
}
}
// Data count section
12 => {
let data_count = section_decoder.decode()?;
builder.set_data_count(data_count);
}
_ => unreachable!(),
}
if !section_decoder.is_at_end() {
return Err(DecodeError::new(""))?;
}
}
builder.finish(engine)
}
/// Returns an iterator over the imports in this [`Module`].
pub fn imports(&self) -> ModuleImports<'_> {
ModuleImports {
imports: self.imports.iter(),
imported_func_types: self.func_types[..self.imported_func_count].iter(),
imported_table_types: self.table_types[..self.imported_table_count].iter(),
imported_memory_types: self.memory_types[..self.imported_memory_count].iter(),
imported_global_types: self.global_types[..self.imported_global_count].iter(),
}
}
/// Returns the [`ExternType`] of the export with the given name in this [`Module`], if it exists.
pub fn export<'a>(&'a self, name: &'a str) -> Option<ExternType> {
self.exports.get(name).map(|&desc| self.extern_type(desc))
}
/// Returns an iterator over the exports in this [`Module`].
pub fn exports(&self) -> ModuleExports<'_> {
ModuleExports {
module: self,
iter: self.exports.iter(),
}
}
pub(crate) fn instantiate(
&self,
store: &mut Store,
linker: &Linker,
) -> Result<Instance, Error> {
let instance = Instance::uninited(store.id());
let mut initer = InstanceIniter::new(store.id());
for type_ in self.types.iter() {
initer.push_type(store.get_or_intern_type(type_));
}
for ((module, name), type_) in self.imports() {
match type_ {
ExternType::Func(type_) => {
let val = linker
.lookup(module, name)
.ok_or(InstantiateError::DefNotFound)?;
let func = val.to_func().ok_or(InstantiateError::ImportKindMismatch)?;
if func.type_(store) != &type_ {
return Err(InstantiateError::FuncTypeMismatch)?;
}
initer.push_func(func);
}
ExternType::Global(type_) => {
let val = linker
.lookup(module, name)
.ok_or(InstantiateError::DefNotFound)?;
let global = val
.to_global()
.ok_or(InstantiateError::ImportKindMismatch)?;
if global.type_(store) != type_ {
return Err(InstantiateError::GlobalTypeMismatch)?;
}
initer.push_global(global);
}
_ => {}
}
}
for (type_, code) in self.internal_funcs() {
let type_ = store.get_or_intern_type(type_);
initer.push_func(Func::new_wasm(store, type_, instance.clone(), code.clone()));
}
let global_init_vals: Vec<_> = self
.internal_globals()
.map(|(_, val)| val.evaluate(store, &initer))
.collect();
let elems: Vec<UnguardedElems> = self
.elems
.iter()
.map(|elem| match elem.type_ {
RefType::FuncRef => UnguardedElems::FuncRef(
elem.elems
.iter()
.map(|elem| {
elem.evaluate(store, &initer)
.to_func_ref()
.unwrap()
.to_unguarded(store.id())
})
.collect(),
),
RefType::ExternRef => UnguardedElems::ExternRef(
elem.elems
.iter()
.map(|elem| {
elem.evaluate(store, &initer)
.to_extern_ref()
.unwrap()
.to_unguarded(store.id())
})
.collect(),
),
})
.collect();
for ((module, name), type_) in self.imports() {
match type_ {
ExternType::Table(type_) => {
let val = linker
.lookup(module, name)
.ok_or(InstantiateError::DefNotFound)?;
let table = val.to_table().ok_or(InstantiateError::ImportKindMismatch)?;
if !table.type_(store).is_subtype_of(type_) {
return Err(InstantiateError::TableTypeMismatch)?;
}
initer.push_table(table);
}
ExternType::Mem(type_) => {
let val = linker
.lookup(module, name)
.ok_or(InstantiateError::DefNotFound)?;
let mem = val.to_mem().ok_or(InstantiateError::ImportKindMismatch)?;
if !mem.type_(store).is_subtype_of(type_) {
return Err(InstantiateError::MemTypeMismatch)?;
}
initer.push_mem(mem);
}
_ => {}
}
}
for type_ in self.internal_tables() {
initer.push_table(Table::new(store, type_, Ref::null(type_.elem)).unwrap());
}
for type_ in self.internal_memories() {
initer.push_mem(Mem::new(store, type_));
}
for ((type_, _), init_val) in self.internal_globals().zip(global_init_vals) {
initer.push_global(Global::new(store, type_, init_val).unwrap());
}
for (name, &desc) in self.exports.iter() {
initer.push_export(
name.clone(),
match desc {
ExternValDesc::Func(idx) => ExternVal::Func(initer.func(idx).unwrap()),
ExternValDesc::Table(idx) => ExternVal::Table(initer.table(idx).unwrap()),
ExternValDesc::Memory(idx) => ExternVal::Memory(initer.mem(idx).unwrap()),
ExternValDesc::Global(idx) => ExternVal::Global(initer.global(idx).unwrap()),
},
);
}
for elems in elems {
initer.push_elem(unsafe { Elem::new_unguarded(store, elems) });
}
for data in self.datas.iter() {
initer.push_data(Data::new(store, data.bytes.clone()));
}
instance.init(initer);
for (elem_idx, elem) in (0u32..).zip(self.elems.iter()) {
let ElemKind::Active {
table_idx,
ref offset,
} = elem.kind
else {
continue;
};
instance.table(table_idx).unwrap().init(
store,
offset.evaluate(store, &instance).to_i32().unwrap() as u32,
instance.elem(elem_idx).unwrap(),
0,
elem.elems.len().try_into().unwrap(),
)?;
instance.elem(elem_idx).unwrap().drop_elems(store);
}
for (elem_idx, elem) in (0u32..).zip(self.elems.iter()) {
let ElemKind::Declarative = elem.kind else {
continue;
};
instance.elem(elem_idx).unwrap().drop_elems(store);
}
for (data_idx, data) in (0u32..).zip(self.datas.iter()) {
let DataKind::Active {
mem_idx,
ref offset,
} = data.kind
else {
continue;
};
instance.mem(mem_idx).unwrap().init(
store,
offset
.evaluate(store, &instance)
.to_i32()
.ok_or(Trap::Unreachable)? as u32,
instance.data(data_idx).unwrap(),
0,
data.bytes.len().try_into().unwrap(),
)?;
instance.data(data_idx).unwrap().drop_bytes(store);
}
if let Some(start) = self.start {
instance.func(start).unwrap().call(store, &[], &mut [])?;
}
Ok(instance)
}
fn func(&self, idx: u32) -> Option<&FuncType> {
let idx = usize::try_from(idx).unwrap();
self.func_types.get(idx)
}
fn table(&self, idx: u32) -> Option<TableType> {
let idx = usize::try_from(idx).unwrap();
self.table_types.get(idx).copied()
}
fn memory(&self, idx: u32) -> Option<MemType> {
let idx = usize::try_from(idx).unwrap();
self.memory_types.get(idx).copied()
}
fn global(&self, idx: u32) -> Option<GlobalType> {
let idx = usize::try_from(idx).unwrap();
self.global_types.get(idx).copied()
}
fn extern_type(&self, desc: ExternValDesc) -> ExternType {
match desc {
ExternValDesc::Func(idx) => self.func(idx).cloned().unwrap().into(),
ExternValDesc::Table(idx) => self.table(idx).unwrap().into(),
ExternValDesc::Memory(idx) => self.memory(idx).unwrap().into(),
ExternValDesc::Global(idx) => self.global(idx).unwrap().into(),
}
}
fn internal_funcs(&self) -> impl Iterator<Item = (&FuncType, &UncompiledCode)> {
self.func_types[self.imported_func_count..]
.iter()
.zip(self.codes.iter())
}
fn internal_tables(&self) -> impl Iterator<Item = TableType> + '_ {
self.table_types[self.imported_table_count..]
.iter()
.copied()
}
fn internal_memories(&self) -> impl Iterator<Item = MemType> + '_ {
self.memory_types[self.imported_memory_count..]
.iter()
.copied()
}
fn internal_globals(&self) -> impl Iterator<Item = (GlobalType, &ConstExpr)> {
self.global_types[self.imported_global_count..]
.iter()
.copied()
.zip(self.global_vals.iter())
}
}
/// An iterator over the imports in a [`Module`].
#[derive(Clone, Debug)]
pub struct ModuleImports<'a> {
imports: slice::Iter<'a, ((Arc<str>, Arc<str>), ImportKind)>,
imported_func_types: slice::Iter<'a, FuncType>,
imported_table_types: slice::Iter<'a, TableType>,
imported_memory_types: slice::Iter<'a, MemType>,
imported_global_types: slice::Iter<'a, GlobalType>,
}
impl<'a> Iterator for ModuleImports<'a> {
type Item = ((&'a str, &'a str), ExternType);
fn next(&mut self) -> Option<Self::Item> {
self.imports.next().map(|((module, name), imported)| {
(
(&**module, &**name),
match imported {
ImportKind::Func => self.imported_func_types.next().cloned().unwrap().into(),
ImportKind::Table => self.imported_table_types.next().copied().unwrap().into(),
ImportKind::Mem => self.imported_memory_types.next().copied().unwrap().into(),
ImportKind::Global => {
self.imported_global_types.next().copied().unwrap().into()
}
},
)
})
}
}
/// An iterator over the exports in a [`Module`].
#[derive(Clone, Debug)]
pub struct ModuleExports<'a> {
module: &'a Module,
iter: hash_map::Iter<'a, Arc<str>, ExternValDesc>,
}
impl<'a> Iterator for ModuleExports<'a> {
type Item = (&'a str, ExternType);
fn next(&mut self) -> Option<Self::Item> {
self.iter
.next()
.map(|(name, &desc)| (&**name, self.module.extern_type(desc)))
}
}
/// A builder for a [`Module`].
#[derive(Debug)]
pub(crate) struct ModuleBuilder {
types: Vec<FuncType>,
imports: Vec<((Arc<str>, Arc<str>), ImportKind)>,
imported_func_count: usize,
imported_table_count: usize,
imported_memory_count: usize,
imported_global_count: usize,
func_types: Vec<FuncType>,
table_types: Vec<TableType>,
memory_types: Vec<MemType>,
global_types: Vec<GlobalType>,
global_vals: Vec<ConstExpr>,
exports: HashMap<Arc<str>, ExternValDesc>,
start: Option<u32>,
codes: Vec<UncompiledCode>,
elems: Vec<ElemDef>,
datas: Vec<DataDef>,
data_count: Option<u32>,
refs: HashSet<u32>,
}
impl ModuleBuilder {
fn new() -> Self {
Self {
types: Vec::new(),
imports: Vec::new(),
imported_func_count: 0,
imported_table_count: 0,
imported_memory_count: 0,
imported_global_count: 0,
func_types: Vec::new(),
table_types: Vec::new(),
memory_types: Vec::new(),
global_types: Vec::new(),
global_vals: Vec::new(),
exports: HashMap::new(),
start: None,
codes: Vec::new(),
elems: Vec::new(),
datas: Vec::new(),
data_count: None,
refs: HashSet::new(),
}
}
pub(crate) fn type_(&self, idx: u32) -> Result<&FuncType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.types
.get(idx)
.ok_or_else(|| DecodeError::new("unknown type"))
}
pub(crate) fn func(&self, idx: u32) -> Result<&FuncType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.func_types
.get(idx)
.ok_or_else(|| DecodeError::new("unknown function"))
}
pub(crate) fn table(&self, idx: u32) -> Result<TableType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.table_types
.get(idx)
.copied()
.ok_or_else(|| DecodeError::new("unknown table"))
}
pub(crate) fn memory(&self, idx: u32) -> Result<MemType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.memory_types
.get(idx)
.copied()
.ok_or_else(|| DecodeError::new("unknown memory"))
}
pub(crate) fn imported_global(&self, idx: u32) -> Result<GlobalType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.global_types[..self.imported_global_count]
.get(idx)
.copied()
.ok_or_else(|| DecodeError::new("unknown global"))
}
pub(crate) fn global(&self, idx: u32) -> Result<GlobalType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.global_types
.get(idx)
.copied()
.ok_or_else(|| DecodeError::new("unknown global"))
}
pub(crate) fn elem(&self, idx: u32) -> Result<RefType, DecodeError> {
let idx = usize::try_from(idx).unwrap();
self.elems
.get(idx)
.map(|elem| elem.type_)
.ok_or_else(|| DecodeError::new("unknown element segment"))
}
pub(crate) fn data(&self, idx: u32) -> Result<(), DecodeError> {
if let Some(data_count) = self.data_count {
if idx >= data_count {
return Err(DecodeError::new("unknown data segment"));
}
Ok(())
} else {
Err(DecodeError::new("missing data count section"))
}
}
pub(crate) fn ref_(&self, func_idx: u32) -> Result<(), DecodeError> {
if !self.refs.contains(&func_idx) {
return Err(DecodeError::new("undeclared reference"));
}
Ok(())
}
fn push_type(&mut self, type_: FuncType) -> Result<(), DecodeError> {
if self.types.len() == config::MAX_TYPE_COUNT {
return Err(DecodeError::new("too many types"));
}
self.types.push(type_);
Ok(())
}
fn push_import(&mut self, import: ImportDef) -> Result<(), DecodeError> {
if self.imports.len() == config::MAX_IMPORT_COUNT {
return Err(DecodeError::new("too many imports"));
}
let key = (import.module, import.name);
match import.desc {
ExternTypeDesc::Func(type_idx) => {
if self.func_types.len() == config::MAX_FUNC_COUNT {
return Err(DecodeError::new("too many functions"));
}
self.imports.push((key, ImportKind::Func));
self.imported_func_count += 1;
self.func_types.push(self.type_(type_idx).cloned()?);
}
ExternTypeDesc::Table(type_) => {
if self.table_types.len() == config::MAX_TABLE_COUNT {
return Err(DecodeError::new("too many tables"));
}
if !type_.is_valid() {
return Err(DecodeError::new("invalid table type"))?;
}
self.imports.push((key, ImportKind::Table));
self.imported_table_count += 1;
self.table_types.push(type_);
}
ExternTypeDesc::Memory(type_) => {
if self.memory_types.len() == config::MAX_MEMORY_COUNT {
return Err(DecodeError::new("too many memories"));
}
if !type_.is_valid() {
return Err(DecodeError::new("invalid memory type"));
}
self.imports.push((key, ImportKind::Mem));
self.imported_memory_count += 1;
self.memory_types.push(type_);
}
ExternTypeDesc::Global(type_) => {
if self.global_types.len() == config::MAX_GLOBAL_COUNT {
return Err(DecodeError::new("too many globals"));
}
self.imports.push((key, ImportKind::Global));
self.imported_global_count += 1;
self.global_types.push(type_);
}
}
Ok(())
}
fn push_func(&mut self, type_idx: u32) -> Result<(), DecodeError> {
if self.func_types.len() == config::MAX_FUNC_COUNT {
return Err(DecodeError::new("too many functions"));
}
let type_ = self.type_(type_idx).cloned()?;
if type_.params().len() > config::MAX_FUNC_PARAM_COUNT {
return Err(DecodeError::new("too many function parameters"));
}
if type_.results().len() > config::MAX_FUNC_RESULT_COUNT {
return Err(DecodeError::new("too many function results"));
}
self.func_types.push(type_);
Ok(())
}
fn push_table(&mut self, table: TableDef) -> Result<(), DecodeError> {
if self.table_types.len() == config::MAX_TABLE_COUNT {
return Err(DecodeError::new("too many tables"));
}
if !table.type_.is_valid() {
return Err(DecodeError::new("invalid table type"))?;
}
self.table_types.push(table.type_);
Ok(())
}
fn push_memory(&mut self, memory: MemDef) -> Result<(), DecodeError> {
if self.memory_types.len() == config::MAX_MEMORY_COUNT {
return Err(DecodeError::new("too many memories"));
}
if !memory.type_.is_valid() {
return Err(DecodeError::new("invalid memory type"));
}
self.memory_types.push(memory.type_);
Ok(())
}
fn push_global(&mut self, global: GlobalDef) -> Result<(), DecodeError> {
if self.global_types.len() == config::MAX_GLOBAL_COUNT {
return Err(DecodeError::new("too many globals"));
}
if global.val.validate(self)? != global.type_.val {
return Err(DecodeError::new("type mismatch"));
}
if let Some(func_idx) = global.val.func_idx() {
self.refs.insert(func_idx);
}
self.global_types.push(global.type_);
self.global_vals.push(global.val);
Ok(())
}
fn push_export(&mut self, export: ExportDef) -> Result<(), DecodeError> {
if self.exports.len() == config::MAX_EXPORT_COUNT {
return Err(DecodeError::new("too many exports"));
}
match export.desc {
ExternValDesc::Func(idx) => {
self.refs.insert(idx);
self.func(idx)?;
}
ExternValDesc::Table(idx) => {
self.table(idx)?;
}
ExternValDesc::Memory(idx) => {
self.memory(idx)?;
}
ExternValDesc::Global(idx) => {
self.global(idx)?;
}
}
if self.exports.contains_key(&export.name) {
return Err(DecodeError::new("duplicate export name"));
}
self.exports.insert(export.name, export.desc);
Ok(())
}
fn set_start(&mut self, start: u32) -> Result<(), DecodeError> {
let type_ = self.func(start)?;
if type_ != &FuncType::from_val_type(None) {
return Err(DecodeError::new("type mismatch"));
}
self.start = Some(start);
Ok(())
}
fn push_code(&mut self, code: UncompiledCode) -> Result<(), DecodeError> {
if self.codes.len() == self.func_types.len() - self.imported_func_count {
return Err(DecodeError::new(
"function and code section have inconsistent sizes",
))?;
}
if code.locals.len() > config::MAX_FUNC_LOCAL_COUNT {
return Err(DecodeError::new("too many function locals"));
}
if code.expr.len() > config::MAX_FUNC_BODY_SIZE {
return Err(DecodeError::new("function body too large"));
}
self.codes.push(code);
Ok(())
}
fn push_elem(&mut self, elem: ElemDef) -> Result<(), DecodeError> {
if self.elems.len() == config::MAX_ELEM_COUNT {
return Err(DecodeError::new("too many element segments"));
}
if elem.elems.len() > config::MAX_ELEM_SIZE {
return Err(DecodeError::new("element segment too large"));
}
if let ElemKind::Active {
table_idx,
ref offset,
} = elem.kind
{
let table = self.table(table_idx)?;
if elem.type_ != table.elem {
return Err(DecodeError::new("type mismatch"));
}
if offset.validate(self)? != ValType::I32 {
return Err(DecodeError::new("type mismatch"));
}
}
for expr in &*elem.elems {
if expr.validate(self)? != elem.type_.into() {
return Err(DecodeError::new("type mismatch"));
}
}
for elem in elem.elems.iter() {
if let Some(func_idx) = elem.func_idx() {
self.refs.insert(func_idx);
}
}
self.elems.push(elem);
Ok(())
}
fn push_data(&mut self, data: DataDef) -> Result<(), DecodeError> {
if self.datas.len() == config::MAX_DATA_COUNT {
return Err(DecodeError::new("too many data segments"));
}
if data.bytes.len() > config::MAX_DATA_SIZE {
return Err(DecodeError::new("data segment too large"));
}
if let DataKind::Active {
mem_idx,
ref offset,
} = data.kind
{
self.memory(mem_idx)?;
if offset.validate(self)? != ValType::I32 {
return Err(DecodeError::new("type mismatch"));
}
}
self.datas.push(data);
Ok(())
}
fn set_data_count(&mut self, data_count: u32) {
self.data_count = Some(data_count);
}
fn finish(self, engine: &Engine) -> Result<Module, DecodeError> {
if self.func_types.len() - self.imported_func_count > self.codes.len() {
return Err(DecodeError::new(
"function and code section have inconsistent sizes",
))?;
}
for (type_, code) in self.func_types[self.imported_func_count..]
.iter()
.zip(self.codes.iter())
{
engine.validate(type_, &self, code)?;
}
if let Some(data_count) = self.data_count {
if data_count != u32::try_from(self.datas.len()).unwrap() {
return Err(DecodeError::new(
"data count and data section have inconsistent sizes",
))?;
}
}
Ok(Module {
types: self.types.into(),
imports: self.imports.into(),
imported_func_count: self.imported_func_count,
imported_table_count: self.imported_table_count,
imported_memory_count: self.imported_memory_count,
imported_global_count: self.imported_global_count,
func_types: self.func_types.into(),
table_types: self.table_types.into(),
memory_types: self.memory_types.into(),
global_types: self.global_types.into(),
global_vals: self.global_vals.into(),
exports: self.exports,
start: self.start,
codes: self.codes.into(),
elems: self.elems.into(),
datas: self.datas.into(),
})
}
}
/// The kind of an import
#[derive(Clone, Copy, Debug)]
enum ImportKind {
Func,
Table,
Mem,
Global,
}
/// A definition for an import.
#[derive(Clone, Debug)]
struct ImportDef {
module: Arc<str>,
name: Arc<str>,
desc: ExternTypeDesc,
}
impl Decode for ImportDef {
fn decode(decoder: &mut Decoder<'_>) -> Result<Self, DecodeError> {
Ok(ImportDef {
module: decoder.decode()?,
name: decoder.decode()?,
desc: decoder.decode()?,
})
}
}
/// A definition for a [`Table`].
#[derive(Debug)]
struct TableDef {
type_: TableType,
}
impl Decode for TableDef {
fn decode(decoder: &mut Decoder) -> Result<Self, DecodeError> {
Ok(Self {
type_: decoder.decode()?,
})
}
}
/// A definition for a [`Mem`].
#[derive(Debug)]
struct MemDef {
type_: MemType,
}
impl Decode for MemDef {
fn decode(decoder: &mut Decoder) -> Result<Self, DecodeError> {
Ok(Self {
type_: decoder.decode()?,
})
}
}
/// A definition for a [`Global`].
#[derive(Clone, Debug)]
struct GlobalDef {
type_: GlobalType,
val: ConstExpr,
}
impl Decode for GlobalDef {
fn decode(decoder: &mut Decoder) -> Result<Self, DecodeError> {
Ok(Self {
type_: decoder.decode()?,
val: decoder.decode()?,
})
}
}
/// A definition for an [`Export`].
#[derive(Clone, Debug)]
struct ExportDef {
name: Arc<str>,
desc: ExternValDesc,
}
impl Decode for ExportDef {
fn decode(decoder: &mut Decoder<'_>) -> Result<Self, DecodeError> {
Ok(Self {
name: decoder.decode()?,
desc: decoder.decode()?,
})
}
}
/// A definition for an [`Elem`].
#[derive(Clone, Debug)]
struct ElemDef {
kind: ElemKind,
type_: RefType,
elems: Arc<[ConstExpr]>,
}
impl Decode for ElemDef {
fn decode(decoder: &mut Decoder<'_>) -> Result<Self, DecodeError> {
let flags: u32 = decoder.decode()?;
Ok(Self {
kind: if flags & 0x01 != 0 {
if flags & 0x02 != 0 {
ElemKind::Declarative
} else {
ElemKind::Passive
}
} else {
ElemKind::Active {
table_idx: if flags & 0x02 != 0 {
decoder.decode()?
} else {
0
},
offset: decoder.decode()?,
}
},
type_: if flags & 0x03 != 0 {
if flags & 0x04 != 0 {
decoder.decode()?
} else {
match decoder.decode()? {
0x00 => RefType::FuncRef,
_ => {
return Err(DecodeError::new("malformed element kind"));
}
}
}
} else {
RefType::FuncRef
},
elems: if flags & 0x04 != 0 {
decoder.decode_iter()?.collect::<Result<_, _>>()?
} else {
decoder
.decode_iter::<u32>()?
.map(|func_idx| func_idx.map(|func_idx| ConstExpr::new_ref_func(func_idx)))
.collect::<Result<_, _>>()?
},
})
}
}
/// The kind of an [`Elem`].
#[derive(Clone, Debug)]
enum ElemKind {
/// Passive [`Elem`]s are used to initialize [`Table`]s during execution.
Passive,
/// Active [`Elem`]s are used to initialize [`Table`]s during instantiation.
Active { table_idx: u32, offset: ConstExpr },
/// Declarative [`Elem`]s are only used during validation.
Declarative,
}
/// A definition for a [`Data`].
#[derive(Clone, Debug)]
pub(crate) struct DataDef {
kind: DataKind,
bytes: Arc<[u8]>,
}
impl Decode for DataDef {
fn decode(decoder: &mut Decoder<'_>) -> Result<Self, DecodeError> {
Ok(Self {
kind: {
let flags: u32 = decoder.decode()?;
if flags & 0x1 != 0 {
DataKind::Passive
} else {
DataKind::Active {
mem_idx: if flags & 0x02 != 0 {
decoder.decode()?
} else {
0
},
offset: decoder.decode()?,
}
}
},
bytes: decoder.decode_decoder()?.read_bytes_until_end().into(),
})
}
}
/// The kind of a [`Data`].
#[derive(Clone, Debug)]
enum DataKind {
/// Passive [`Data`]s are used to initialize a [`Mem`] during execution.
Passive,
/// Active [`Data`]s are used to initialize a [`Mem`] during instantiation.
Active { mem_idx: u32, offset: ConstExpr },
}