#[cfg(feature = "component-model")]
use crate::component::WastVal;
use crate::core::{WastArgCore, WastRetCore};
use crate::kw;
use crate::parser::{self, Cursor, Parse, ParseBuffer, Parser, Peek, Result};
use crate::token::{Id, Span};
use crate::{Error, Wat};
/// A parsed representation of a `*.wast` file.
///
/// WAST files are not officially specified but are used in the official test
/// suite to write official spec tests for wasm. This type represents a parsed
/// `*.wast` file which parses a list of directives in a file.
#[derive(Debug)]
pub struct Wast<'a> {
#[allow(missing_docs)]
pub directives: Vec<WastDirective<'a>>,
}
impl<'a> Parse<'a> for Wast<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
let mut directives = Vec::new();
parser.with_standard_annotations_registered(|parser| {
// If it looks like a directive token is in the stream then we parse a
// bunch of directives, otherwise assume this is an inline module.
if parser.peek2::<WastDirectiveToken>()? {
while !parser.is_empty() {
directives.push(parser.parens(|p| p.parse())?);
}
} else {
let module = parser.parse::<Wat>()?;
directives.push(WastDirective::Module(QuoteWat::Wat(module)));
}
Ok(Wast { directives })
})
}
}
struct WastDirectiveToken;
impl Peek for WastDirectiveToken {
fn peek(cursor: Cursor<'_>) -> Result<bool> {
let kw = match cursor.keyword()? {
Some((kw, _)) => kw,
None => return Ok(false),
};
Ok(kw.starts_with("assert_")
|| kw == "module"
|| kw == "component"
|| kw == "register"
|| kw == "invoke")
}
fn display() -> &'static str {
unimplemented!()
}
}
/// The different kinds of directives found in a `*.wast` file.
///
///
/// Some more information about these various branches can be found at
/// <
https://github.com/WebAssembly/spec/blob/main/interpreter/README.md#scripts>.
#[allow(missing_docs)]
#[derive(Debug)]
pub enum WastDirective<'a> {
/// The provided module is defined, validated, and then instantiated.
Module(QuoteWat<'a>),
/// The provided module is defined and validated.
///
/// This module is not instantiated automatically.
ModuleDefinition(QuoteWat<'a>),
/// The named module is instantiated under the instance name provided.
ModuleInstance {
span: Span,
instance: Option<Id<'a>>,
module: Option<Id<'a>>,
},
/// Asserts the module cannot be decoded with the given error.
AssertMalformed {
span: Span,
module: QuoteWat<'a>,
message: &'a str,
},
/// Asserts the module cannot be validated with the given error.
AssertInvalid {
span: Span,
module: QuoteWat<'a>,
message: &'a str,
},
/// Registers the `module` instance with the given `name` to be available
/// for importing in future module instances.
Register {
span: Span,
name: &'a str,
module: Option<Id<'a>>,
},
/// Invokes the specified export.
Invoke(WastInvoke<'a>),
/// The invocation provided should trap with the specified error.
AssertTrap {
span: Span,
exec: WastExecute<'a>,
message: &'a str,
},
/// The invocation provided should succeed with the specified results.
AssertReturn {
span: Span,
exec: WastExecute<'a>,
results: Vec<WastRet<'a>>,
},
/// The invocation provided should exhaust system resources (e.g. stack
/// overflow).
AssertExhaustion {
span: Span,
call: WastInvoke<'a>,
message: &'a str,
},
/// The provided module should fail to link when instantiation is attempted.
AssertUnlinkable {
span: Span,
module: Wat<'a>,
message: &'a str,
},
/// The invocation provided should throw an exception.
AssertException { span: Span, exec: WastExecute<'a> },
/// The invocation should fail to handle a suspension.
AssertSuspension {
span: Span,
exec: WastExecute<'a>,
message: &'a str,
},
/// Creates a new system thread which executes the given commands.
Thread(WastThread<'a>),
/// Waits for the specified thread to exit.
Wait { span: Span, thread: Id<'a> },
}
impl WastDirective<'_> {
/// Returns the location in the source that this directive was defined at
pub fn span(&self) -> Span {
match self {
WastDirective::Module(QuoteWat::Wat(w))
| WastDirective::ModuleDefinition(QuoteWat::Wat(w)) => w.span(),
WastDirective::Module(QuoteWat::QuoteModule(span, _))
| WastDirective::ModuleDefinition(QuoteWat::QuoteModule(span, _)) => *span,
WastDirective::Module(QuoteWat::QuoteComponent(span, _))
| WastDirective::ModuleDefinition(QuoteWat::QuoteComponent(span, _)) => *span,
WastDirective::ModuleInstance { span, .. }
| WastDirective::AssertMalformed { span, .. }
| WastDirective::Register { span, .. }
| WastDirective::AssertTrap { span, .. }
| WastDirective::AssertReturn { span, .. }
| WastDirective::AssertExhaustion { span, .. }
| WastDirective::AssertUnlinkable { span, .. }
| WastDirective::AssertInvalid { span, .. }
| WastDirective::AssertException { span, .. }
| WastDirective::AssertSuspension { span, .. }
| WastDirective::Wait { span, .. } => *span,
WastDirective::Invoke(i) => i.span,
WastDirective::Thread(t) => t.span,
}
}
}
impl<'a> Parse<'a> for WastDirective<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
let mut l = parser.lookahead1();
if l.peek::<kw::module>()? || l.peek::<kw::component>()? {
parse_wast_module(parser)
} else if l.peek::<kw::assert_malformed>()? {
let span = parser.parse::<kw::assert_malformed>()?.0;
Ok(WastDirective::AssertMalformed {
span,
module: parser.parens(|p| p.parse())?,
message: parser.parse()?,
})
} else if l.peek::<kw::assert_invalid>()? {
let span = parser.parse::<kw::assert_invalid>()?.0;
Ok(WastDirective::AssertInvalid {
span,
module: parser.parens(|p| p.parse())?,
message: parser.parse()?,
})
} else if l.peek::<kw::register>()? {
let span = parser.parse::<kw::register>()?.0;
Ok(WastDirective::Register {
span,
name: parser.parse()?,
module: parser.parse()?,
})
} else if l.peek::<kw::invoke>()? {
Ok(WastDirective::Invoke(parser.parse()?))
} else if l.peek::<kw::assert_trap>()? {
let span = parser.parse::<kw::assert_trap>()?.0;
Ok(WastDirective::AssertTrap {
span,
exec: parser.parens(|p| p.parse())?,
message: parser.parse()?,
})
} else if l.peek::<kw::assert_return>()? {
let span = parser.parse::<kw::assert_return>()?.0;
let exec = parser.parens(|p| p.parse())?;
let mut results = Vec::new();
while !parser.is_empty() {
results.push(parser.parens(|p| p.parse())?);
}
Ok(WastDirective::AssertReturn {
span,
exec,
results,
})
} else if l.peek::<kw::assert_exhaustion>()? {
let span = parser.parse::<kw::assert_exhaustion>()?.0;
Ok(WastDirective::AssertExhaustion {
span,
call: parser.parens(|p| p.parse())?,
message: parser.parse()?,
})
} else if l.peek::<kw::assert_unlinkable>()? {
let span = parser.parse::<kw::assert_unlinkable>()?.0;
Ok(WastDirective::AssertUnlinkable {
span,
module: parser.parens(parse_wat)?,
message: parser.parse()?,
})
} else if l.peek::<kw::assert_exception>()? {
let span = parser.parse::<kw::assert_exception>()?.0;
Ok(WastDirective::AssertException {
span,
exec: parser.parens(|p| p.parse())?,
})
} else if l.peek::<kw::assert_suspension>()? {
let span = parser.parse::<kw::assert_suspension>()?.0;
Ok(WastDirective::AssertSuspension {
span,
exec: parser.parens(|p| p.parse())?,
message: parser.parse()?,
})
} else if l.peek::<kw::thread>()? {
Ok(WastDirective::Thread(parser.parse()?))
} else if l.peek::<kw::wait>()? {
let span = parser.parse::<kw::wait>()?.0;
Ok(WastDirective::Wait {
span,
thread: parser.parse()?,
})
} else {
Err(l.error())
}
}
}
#[allow(missing_docs)]
#[derive(Debug)]
pub enum WastExecute<'a> {
Invoke(WastInvoke<'a>),
Wat(Wat<'a>),
Get {
span: Span,
module: Option<Id<'a>>,
global: &'a str,
},
}
impl<'a> WastExecute<'a> {
/// Returns the first span for this execute statement.
pub fn span(&self) -> Span {
match self {
WastExecute::Invoke(i) => i.span,
WastExecute::Wat(i) => i.span(),
WastExecute::Get { span, .. } => *span,
}
}
}
impl<'a> Parse<'a> for WastExecute<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
let mut l = parser.lookahead1();
if l.peek::<kw::invoke>()? {
Ok(WastExecute::Invoke(parser.parse()?))
} else if l.peek::<kw::module>()? || l.peek::<kw::component>()? {
Ok(WastExecute::Wat(parse_wat(parser)?))
} else if l.peek::<kw::get>()? {
let span = parser.parse::<kw::get>()?.0;
Ok(WastExecute::Get {
span,
module: parser.parse()?,
global: parser.parse()?,
})
} else {
Err(l.error())
}
}
}
fn parse_wat(parser: Parser) -> Result<Wat> {
// Note that this doesn't use `Parse for Wat` since the `parser` provided
// has already peeled back the first layer of parentheses while `Parse for
// Wat` expects to be the top layer which means it also tries to peel off
// the parens. Instead we can skip the sugar that `Wat` has for simply a
// list of fields (no `(module ...)` container) and just parse the `Module`
// itself.
if parser.peek::<kw::component>()? {
Ok(Wat::Component(parser.parse()?))
} else {
Ok(Wat::Module(parser.parse()?))
}
}
#[allow(missing_docs)]
#[derive(Debug)]
pub struct WastInvoke<'a> {
pub span: Span,
pub module: Option<Id<'a>>,
pub name: &'a str,
pub args: Vec<WastArg<'a>>,
}
impl<'a> Parse<'a> for WastInvoke<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
let span = parser.parse::<kw::invoke>()?.0;
let module = parser.parse()?;
let name = parser.parse()?;
let mut args = Vec::new();
while !parser.is_empty() {
args.push(parser.parens(|p| p.parse())?);
}
Ok(WastInvoke {
span,
module,
name,
args,
})
}
}
fn parse_wast_module<'a>(parser: Parser<'a>) -> Result<WastDirective<'a>> {
if parser.peek2::<kw::quote>()? {
QuoteWat::parse(parser).map(WastDirective::Module)
} else if parser.peek2::<kw::definition>()? {
fn parse_module(span: Span, parser: Parser<'_>) -> Result<Wat<'_>> {
Ok(Wat::Module(
crate::core::Module::parse_without_module_keyword(span, parser)?,
))
}
fn parse_component(_span: Span, parser: Parser<'_>) -> Result<Wat<'_>> {
#[cfg(feature = "component-model")]
return Ok(Wat::Component(
crate::component::Component::parse_without_component_keyword(_span, parser)?,
));
#[cfg(not(feature = "component-model"))]
return Err(parser.error("component model support disabled at compile time"));
}
let (span, ctor) = if parser.peek::<kw::component>()? {
(
parser.parse::<kw::component>()?.0,
parse_component as fn(_, _) -> _,
)
} else {
(
parser.parse::<kw::module>()?.0,
parse_module as fn(_, _) -> _,
)
};
parser.parse::<kw::definition>()?;
Ok(WastDirective::ModuleDefinition(QuoteWat::Wat(ctor(
span, parser,
)?)))
} else if parser.peek2::<kw::instance>()? {
let span = if parser.peek::<kw::component>()? {
parser.parse::<kw::component>()?.0
} else {
parser.parse::<kw::module>()?.0
};
parser.parse::<kw::instance>()?;
Ok(WastDirective::ModuleInstance {
span,
instance: parser.parse()?,
module: parser.parse()?,
})
} else {
QuoteWat::parse(parser).map(WastDirective::Module)
}
}
#[allow(missing_docs)]
#[derive(Debug)]
pub enum QuoteWat<'a> {
Wat(Wat<'a>),
QuoteModule(Span, Vec<(Span, &'a [u8])>),
QuoteComponent(Span, Vec<(Span, &'a [u8])>),
}
impl<'a> QuoteWat<'a> {
/// Encodes this module to bytes, either by encoding the module directly or
/// parsing the contents and then encoding it.
pub fn encode(&mut self) -> Result<Vec<u8>, Error> {
match self.to_test()? {
QuoteWatTest::Binary(bytes) => Ok(bytes),
QuoteWatTest::Text(text) => {
let text = std::str::from_utf8(&text).map_err(|_| {
let span = self.span();
Error::new(span, "malformed UTF-8 encoding".to_string())
})?;
let buf = ParseBuffer::new(&text)?;
let mut wat = parser::parse::<Wat<'_>>(&buf)?;
wat.encode()
}
}
}
/// Converts this to either a `QuoteWatTest::Binary` or
/// `QuoteWatTest::Text` depending on what it is internally.
pub fn to_test(&mut self) -> Result<QuoteWatTest, Error> {
let (source, prefix) = match self {
QuoteWat::Wat(m) => return m.encode().map(QuoteWatTest::Binary),
QuoteWat::QuoteModule(_, source) => (source, None),
QuoteWat::QuoteComponent(_, source) => (source, Some("(component")),
};
let mut ret = Vec::new();
for (_, src) in source {
ret.extend_from_slice(src);
ret.push(b' ');
}
if let Some(prefix) = prefix {
ret.splice(0..0, prefix.as_bytes().iter().copied());
ret.push(b')');
}
Ok(QuoteWatTest::Text(ret))
}
/// Returns the identifier, if registered, for this module.
pub fn name(&self) -> Option<Id<'a>> {
match self {
QuoteWat::Wat(Wat::Module(m)) => m.id,
QuoteWat::Wat(Wat::Component(m)) => m.id,
QuoteWat::QuoteModule(..) | QuoteWat::QuoteComponent(..) => None,
}
}
/// Returns the defining span of this module.
pub fn span(&self) -> Span {
match self {
QuoteWat::Wat(w) => w.span(),
QuoteWat::QuoteModule(span, _) => *span,
QuoteWat::QuoteComponent(span, _) => *span,
}
}
}
impl<'a> Parse<'a> for QuoteWat<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
if parser.peek2::<kw::quote>()? {
let ctor = if parser.peek::<kw::component>()? {
parser.parse::<kw::component>()?;
QuoteWat::QuoteComponent
} else {
parser.parse::<kw::module>()?;
QuoteWat::QuoteModule
};
let span = parser.parse::<kw::quote>()?.0;
let mut src = Vec::new();
while !parser.is_empty() {
let span = parser.cur_span();
let string = parser.parse()?;
src.push((span, string));
}
Ok(ctor(span, src))
} else {
Ok(QuoteWat::Wat(parse_wat(parser)?))
}
}
}
/// Returned from [`QuoteWat::to_test`].
#[allow(missing_docs)]
#[derive(Debug)]
pub enum QuoteWatTest {
Binary(Vec<u8>),
Text(Vec<u8>),
}
#[derive(Debug)]
#[allow(missing_docs)]
pub enum WastArg<'a> {
Core(WastArgCore<'a>),
// TODO: technically this isn't cargo-compliant since it means that this
// isn't and additive feature by defining this conditionally. That being
// said this seems unlikely to break many in practice so this isn't a shared
// type, so fixing this is left to a future commit.
#[cfg(feature = "component-model")]
Component(WastVal<'a>),
}
impl<'a> Parse<'a> for WastArg<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
#[cfg(feature = "component-model")]
if parser.peek::<WastArgCore<'_>>()? {
Ok(WastArg::Core(parser.parse()?))
} else {
Ok(WastArg::Component(parser.parse()?))
}
#[cfg(not(feature = "component-model"))]
Ok(WastArg::Core(parser.parse()?))
}
}
#[derive(Debug)]
#[allow(missing_docs)]
pub enum WastRet<'a> {
Core(WastRetCore<'a>),
#[cfg(feature = "component-model")]
Component(WastVal<'a>),
}
impl<'a> Parse<'a> for WastRet<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
#[cfg(feature = "component-model")]
if parser.peek::<WastRetCore<'_>>()? {
Ok(WastRet::Core(parser.parse()?))
} else {
Ok(WastRet::Component(parser.parse()?))
}
#[cfg(not(feature = "component-model"))]
Ok(WastRet::Core(parser.parse()?))
}
}
#[derive(Debug)]
#[allow(missing_docs)]
pub struct WastThread<'a> {
pub span: Span,
pub name: Id<'a>,
pub shared_module: Option<Id<'a>>,
pub directives: Vec<WastDirective<'a>>,
}
impl<'a> Parse<'a> for WastThread<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
parser.depth_check()?;
let span = parser.parse::<kw::thread>()?.0;
let name = parser.parse()?;
let shared_module = if parser.peek2::<kw::shared>()? {
let name = parser.parens(|p| {
p.parse::<kw::shared>()?;
p.parens(|p| {
p.parse::<kw::module>()?;
p.parse()
})
})?;
Some(name)
} else {
None
};
let mut directives = Vec::new();
while !parser.is_empty() {
directives.push(parser.parens(|p| p.parse())?);
}
Ok(WastThread {
span,
name,
shared_module,
directives,
})
}
}
