naga/back/wgsl/
mod.rs

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1/*!
2Backend for [WGSL][wgsl] (WebGPU Shading Language).
3
4[wgsl]: https://gpuweb.github.io/gpuweb/wgsl.html
5*/
6
7mod polyfill;
8mod writer;
9
10use alloc::format;
11use alloc::string::String;
12
13use thiserror::Error;
14
15pub use writer::{Writer, WriterFlags};
16
17use crate::common::wgsl;
18
19#[derive(Error, Debug)]
20pub enum Error {
21    #[error(transparent)]
22    FmtError(#[from] core::fmt::Error),
23    #[error("{0}")]
24    Custom(String),
25    #[error("{0}")]
26    Unimplemented(String), // TODO: Error used only during development
27    #[error("Unsupported relational function: {0:?}")]
28    UnsupportedRelationalFunction(crate::RelationalFunction),
29    #[error("Unsupported {kind}: {value}")]
30    Unsupported {
31        /// What kind of unsupported thing this is: interpolation, builtin, etc.
32        kind: &'static str,
33
34        /// The debug form of the Naga IR value that this backend can't express.
35        value: String,
36    },
37}
38
39impl Error {
40    /// Produce an [`Unsupported`] error for `value`.
41    ///
42    /// [`Unsupported`]: Error::Unsupported
43    fn unsupported<T: core::fmt::Debug>(kind: &'static str, value: T) -> Error {
44        Error::Unsupported {
45            kind,
46            value: format!("{value:?}"),
47        }
48    }
49}
50
51trait ToWgslIfImplemented {
52    fn to_wgsl_if_implemented(self) -> Result<&'static str, Error>;
53}
54
55impl<T> ToWgslIfImplemented for T
56where
57    T: wgsl::TryToWgsl + core::fmt::Debug + Copy,
58{
59    fn to_wgsl_if_implemented(self) -> Result<&'static str, Error> {
60        self.try_to_wgsl()
61            .ok_or_else(|| Error::unsupported(T::DESCRIPTION, self))
62    }
63}
64
65pub fn write_string(
66    module: &crate::Module,
67    info: &crate::valid::ModuleInfo,
68    flags: WriterFlags,
69) -> Result<String, Error> {
70    let mut w = Writer::new(String::new(), flags);
71    w.write(module, info)?;
72    let output = w.finish();
73    Ok(output)
74}
75
76impl crate::AtomicFunction {
77    const fn to_wgsl(self) -> &'static str {
78        match self {
79            Self::Add => "Add",
80            Self::Subtract => "Sub",
81            Self::And => "And",
82            Self::InclusiveOr => "Or",
83            Self::ExclusiveOr => "Xor",
84            Self::Min => "Min",
85            Self::Max => "Max",
86            Self::Exchange { compare: None } => "Exchange",
87            Self::Exchange { .. } => "CompareExchangeWeak",
88        }
89    }
90}
naga/back/wgsl/mod.rs

naga/back/wgsl/
mod.rs
