naga/front/wgsl/
mod.rs

1/*!
2Frontend for [WGSL][wgsl] (WebGPU Shading Language).
3
4[wgsl]: https://gpuweb.github.io/gpuweb/wgsl.html
5*/
6
7mod error;
8mod index;
9mod lower;
10mod parse;
11#[cfg(test)]
12mod tests;
13
14pub use crate::front::wgsl::error::ParseError;
15pub use crate::front::wgsl::parse::directive::language_extension::{
16    ImplementedLanguageExtension, LanguageExtension, UnimplementedLanguageExtension,
17};
18
19use alloc::boxed::Box;
20use thiserror::Error;
21
22use crate::front::wgsl::error::Error;
23use crate::front::wgsl::lower::Lowerer;
24use crate::front::wgsl::parse::Parser;
25use crate::Scalar;
26
27#[cfg(test)]
28use std::println;
29
30pub(crate) type Result<'a, T> = core::result::Result<T, Box<Error<'a>>>;
31
32pub struct Frontend {
33    parser: Parser,
34}
35
36impl Frontend {
37    pub const fn new() -> Self {
38        Self {
39            parser: Parser::new(),
40        }
41    }
42
43    pub fn parse(&mut self, source: &str) -> core::result::Result<crate::Module, ParseError> {
44        self.inner(source).map_err(|x| x.as_parse_error(source))
45    }
46
47    fn inner<'a>(&mut self, source: &'a str) -> Result<'a, crate::Module> {
48        let tu = self.parser.parse(source)?;
49        let index = index::Index::generate(&tu)?;
50        let module = Lowerer::new(&index).lower(tu)?;
51
52        Ok(module)
53    }
54}
55
56/// <div class="warning">
57// NOTE: Keep this in sync with `wgpu::Device::create_shader_module`!
58// NOTE: Keep this in sync with `wgpu_core::Global::device_create_shader_module`!
59///
60/// This function may consume a lot of stack space. Compiler-enforced limits for parsing recursion
61/// exist; if shader compilation runs into them, it will return an error gracefully. However, on
62/// some build profiles and platforms, the default stack size for a thread may be exceeded before
63/// this limit is reached during parsing. Callers should ensure that there is enough stack space
64/// for this, particularly if calls to this method are exposed to user input.
65///
66/// </div>
67pub fn parse_str(source: &str) -> core::result::Result<crate::Module, ParseError> {
68    Frontend::new().parse(source)
69}
70
71#[cfg(test)]
72#[track_caller]
73pub fn assert_parse_err(input: &str, snapshot: &str) {
74    let output = parse_str(input)
75        .expect_err("expected parser error")
76        .emit_to_string(input);
77    if output != snapshot {
78        for diff in diff::lines(snapshot, &output) {
79            match diff {
80                diff::Result::Left(l) => println!("-{l}"),
81                diff::Result::Both(l, _) => println!(" {l}"),
82                diff::Result::Right(r) => println!("+{r}"),
83            }
84        }
85        panic!("Error snapshot failed");
86    }
87}
naga/front/wgsl/mod.rs

naga/front/wgsl/
mod.rs
