bevy/crates/bevy_macro_utils/src/attrs.rs

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use syn::DeriveInput;
use crate::symbol::Symbol;
pub fn parse_attrs(ast: &DeriveInput, attr_name: Symbol) -> syn::Result<Vec<syn::NestedMeta>> {
let mut list = Vec::new();
for attr in ast.attrs.iter().filter(|a| a.path == attr_name) {
match attr.parse_meta()? {
syn::Meta::List(meta) => list.extend(meta.nested.into_iter()),
other => {
return Err(syn::Error::new_spanned(
other,
format!("expected #[{attr_name}(...)]"),
))
}
}
}
Ok(list)
}
pub fn get_lit_str(attr_name: Symbol, lit: &syn::Lit) -> syn::Result<&syn::LitStr> {
if let syn::Lit::Str(lit) = lit {
Ok(lit)
} else {
Err(syn::Error::new_spanned(
lit,
format!("expected {attr_name} attribute to be a string: `{attr_name} = \"...\"`"),
))
}
}
Derive AsBindGroup Improvements: Better errors, more options, update examples (#5364) # Objective - Provide better compile-time errors and diagnostics. - Add more options to allow more textures types and sampler types. - Update array_texture example to use upgraded AsBindGroup derive macro. ## Solution Split out the parsing of the inner struct/field attributes (the inside part of a `#[foo(...)]` attribute) for better clarity Parse the binding index for all inner attributes, as it is part of all attributes (`#[foo(0, ...)`), then allow each attribute implementer to parse the rest of the attribute metadata as needed. This should make it very trivial to extend/change if needed in the future. Replaced invocations of `panic!` with the `syn::Error` type, providing fine-grained errors that retains span information. This provides much nicer compile-time errors, and even better IDE errors. ![image](https://user-images.githubusercontent.com/7478134/179452241-6d85d440-4b67-44da-80a7-9d47e8c88b8a.png) Updated the array_texture example to demonstrate the new changes. ## New AsBindGroup attribute options ### `#[texture(u32, ...)]` Where `...` is an optional list of arguments. | Arguments | Values | Default | |-------------- |---------------------------------------------------------------- | ----------- | | dimension = "..." | `"1d"`, `"2d"`, `"2d_array"`, `"3d"`, `"cube"`, `"cube_array"` | `"2d"` | | sample_type = "..." | `"float"`, `"depth"`, `"s_int"` or `"u_int"` | `"float"` | | filterable = ... | `true`, `false` | `true` | | multisampled = ... | `true`, `false` | `false` | | visibility(...) | `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` | `vertex`, `fragment` | Example: `#[texture(0, dimension = "2d_array", visibility(vertex, fragment))]` ### `#[sampler(u32, ...)]` Where `...` is an optional list of arguments. | Arguments | Values | Default | |----------- |--------------------------------------------------- | ----------- | | sampler_type = "..." | `"filtering"`, `"non_filtering"`, `"comparison"`. | `"filtering"` | | visibility(...) | `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` | `vertex`, `fragment` | Example: `#[sampler(0, sampler_type = "filtering", visibility(vertex, fragment)]` ## Changelog - Added more options to `#[texture(...)]` and `#[sampler(...)]` attributes, supporting more kinds of materials. See above for details. - Upgraded IDE and compile-time error messages. - Updated array_texture example using the new options.
2022-07-19 22:05:43 +00:00
pub fn get_lit_bool(attr_name: Symbol, lit: &syn::Lit) -> syn::Result<bool> {
if let syn::Lit::Bool(lit) = lit {
Ok(lit.value())
} else {
Err(syn::Error::new_spanned(
lit,
format!("expected {attr_name} attribute to be a bool value, `true` or `false`: `{attr_name} = ...`"),
Derive AsBindGroup Improvements: Better errors, more options, update examples (#5364) # Objective - Provide better compile-time errors and diagnostics. - Add more options to allow more textures types and sampler types. - Update array_texture example to use upgraded AsBindGroup derive macro. ## Solution Split out the parsing of the inner struct/field attributes (the inside part of a `#[foo(...)]` attribute) for better clarity Parse the binding index for all inner attributes, as it is part of all attributes (`#[foo(0, ...)`), then allow each attribute implementer to parse the rest of the attribute metadata as needed. This should make it very trivial to extend/change if needed in the future. Replaced invocations of `panic!` with the `syn::Error` type, providing fine-grained errors that retains span information. This provides much nicer compile-time errors, and even better IDE errors. ![image](https://user-images.githubusercontent.com/7478134/179452241-6d85d440-4b67-44da-80a7-9d47e8c88b8a.png) Updated the array_texture example to demonstrate the new changes. ## New AsBindGroup attribute options ### `#[texture(u32, ...)]` Where `...` is an optional list of arguments. | Arguments | Values | Default | |-------------- |---------------------------------------------------------------- | ----------- | | dimension = "..." | `"1d"`, `"2d"`, `"2d_array"`, `"3d"`, `"cube"`, `"cube_array"` | `"2d"` | | sample_type = "..." | `"float"`, `"depth"`, `"s_int"` or `"u_int"` | `"float"` | | filterable = ... | `true`, `false` | `true` | | multisampled = ... | `true`, `false` | `false` | | visibility(...) | `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` | `vertex`, `fragment` | Example: `#[texture(0, dimension = "2d_array", visibility(vertex, fragment))]` ### `#[sampler(u32, ...)]` Where `...` is an optional list of arguments. | Arguments | Values | Default | |----------- |--------------------------------------------------- | ----------- | | sampler_type = "..." | `"filtering"`, `"non_filtering"`, `"comparison"`. | `"filtering"` | | visibility(...) | `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` | `vertex`, `fragment` | Example: `#[sampler(0, sampler_type = "filtering", visibility(vertex, fragment)]` ## Changelog - Added more options to `#[texture(...)]` and `#[sampler(...)]` attributes, supporting more kinds of materials. See above for details. - Upgraded IDE and compile-time error messages. - Updated array_texture example using the new options.
2022-07-19 22:05:43 +00:00
))
}
}