Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 232 insertions, 0 deletions

diff --git a/third_party/rust/naga/src/front/glsl/mod.rs b/third_party/rust/naga/src/front/glsl/mod.rs
new file mode 100644
index 0000000000..75f3929db4
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+++ b/third_party/rust/naga/src/front/glsl/mod.rs
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+/*!
+Frontend for [GLSL][glsl] (OpenGL Shading Language).
+
+To begin, take a look at the documentation for the [`Frontend`].
+
+# Supported versions
+## Vulkan
+- 440 (partial)
+- 450
+- 460
+
+[glsl]: https://www.khronos.org/registry/OpenGL/index_gl.php
+*/
+
+pub use ast::{Precision, Profile};
+pub use error::{Error, ErrorKind, ExpectedToken, ParseError};
+pub use token::TokenValue;
+
+use crate::{proc::Layouter, FastHashMap, FastHashSet, Handle, Module, ShaderStage, Span, Type};
+use ast::{EntryArg, FunctionDeclaration, GlobalLookup};
+use parser::ParsingContext;
+
+mod ast;
+mod builtins;
+mod context;
+mod error;
+mod functions;
+mod lex;
+mod offset;
+mod parser;
+#[cfg(test)]
+mod parser_tests;
+mod token;
+mod types;
+mod variables;
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Per-shader options passed to [`parse`](Frontend::parse).
+///
+/// The [`From`] trait is implemented for [`ShaderStage`] to provide a quick way
+/// to create an `Options` instance.
+///
+/// ```rust
+/// # use naga::ShaderStage;
+/// # use naga::front::glsl::Options;
+/// Options::from(ShaderStage::Vertex);
+/// ```
+#[derive(Debug)]
+pub struct Options {
+    /// The shader stage in the pipeline.
+    pub stage: ShaderStage,
+    /// Preprocessor definitions to be used, akin to having
+    /// ```glsl
+    /// #define key value
+    /// ```
+    /// for each key value pair in the map.
+    pub defines: FastHashMap<String, String>,
+}
+
+impl From<ShaderStage> for Options {
+    fn from(stage: ShaderStage) -> Self {
+        Options {
+            stage,
+            defines: FastHashMap::default(),
+        }
+    }
+}
+
+/// Additional information about the GLSL shader.
+///
+/// Stores additional information about the GLSL shader which might not be
+/// stored in the shader [`Module`].
+#[derive(Debug)]
+pub struct ShaderMetadata {
+    /// The GLSL version specified in the shader through the use of the
+    /// `#version` preprocessor directive.
+    pub version: u16,
+    /// The GLSL profile specified in the shader through the use of the
+    /// `#version` preprocessor directive.
+    pub profile: Profile,
+    /// The shader stage in the pipeline, passed to the [`parse`](Frontend::parse)
+    /// method via the [`Options`] struct.
+    pub stage: ShaderStage,
+
+    /// The workgroup size for compute shaders, defaults to `[1; 3]` for
+    /// compute shaders and `[0; 3]` for non compute shaders.
+    pub workgroup_size: [u32; 3],
+    /// Whether or not early fragment tests where requested by the shader.
+    /// Defaults to `false`.
+    pub early_fragment_tests: bool,
+
+    /// The shader can request extensions via the
+    /// `#extension` preprocessor directive, in the directive a behavior
+    /// parameter is used to control whether the extension should be disabled,
+    /// warn on usage, enabled if possible or required.
+    ///
+    /// This field only stores extensions which were required or requested to
+    /// be enabled if possible and they are supported.
+    pub extensions: FastHashSet<String>,
+}
+
+impl ShaderMetadata {
+    fn reset(&mut self, stage: ShaderStage) {
+        self.version = 0;
+        self.profile = Profile::Core;
+        self.stage = stage;
+        self.workgroup_size = [u32::from(stage == ShaderStage::Compute); 3];
+        self.early_fragment_tests = false;
+        self.extensions.clear();
+    }
+}
+
+impl Default for ShaderMetadata {
+    fn default() -> Self {
+        ShaderMetadata {
+            version: 0,
+            profile: Profile::Core,
+            stage: ShaderStage::Vertex,
+            workgroup_size: [0; 3],
+            early_fragment_tests: false,
+            extensions: FastHashSet::default(),
+        }
+    }
+}
+
+/// The `Frontend` is the central structure of the GLSL frontend.
+///
+/// To instantiate a new `Frontend` the [`Default`] trait is used, so a
+/// call to the associated function [`Frontend::default`](Frontend::default) will
+/// return a new `Frontend` instance.
+///
+/// To parse a shader simply call the [`parse`](Frontend::parse) method with a
+/// [`Options`] struct and a [`&str`](str) holding the glsl code.
+///
+/// The `Frontend` also provides the [`metadata`](Frontend::metadata) to get some
+/// further information about the previously parsed shader, like version and
+/// extensions used (see the documentation for
+/// [`ShaderMetadata`] to see all the returned information)
+///
+/// # Example usage
+/// ```rust
+/// use naga::ShaderStage;
+/// use naga::front::glsl::{Frontend, Options};
+///
+/// let glsl = r#"
+///     #version 450 core
+///
+///     void main() {}
+/// "#;
+///
+/// let mut frontend = Frontend::default();
+/// let options = Options::from(ShaderStage::Vertex);
+/// frontend.parse(&options, glsl);
+/// ```
+///
+/// # Reusability
+///
+/// If there's a need to parse more than one shader reusing the same `Frontend`
+/// instance may be beneficial since internal allocations will be reused.
+///
+/// Calling the [`parse`](Frontend::parse) method multiple times will reset the
+/// `Frontend` so no extra care is needed when reusing.
+#[derive(Debug, Default)]
+pub struct Frontend {
+    meta: ShaderMetadata,
+
+    lookup_function: FastHashMap<String, FunctionDeclaration>,
+    lookup_type: FastHashMap<String, Handle<Type>>,
+
+    global_variables: Vec<(String, GlobalLookup)>,
+
+    entry_args: Vec<EntryArg>,
+
+    layouter: Layouter,
+
+    errors: Vec<Error>,
+}
+
+impl Frontend {
+    fn reset(&mut self, stage: ShaderStage) {
+        self.meta.reset(stage);
+
+        self.lookup_function.clear();
+        self.lookup_type.clear();
+        self.global_variables.clear();
+        self.entry_args.clear();
+        self.layouter.clear();
+    }
+
+    /// Parses a shader either outputting a shader [`Module`] or a list of
+    /// [`Error`]s.
+    ///
+    /// Multiple calls using the same `Frontend` and different shaders are supported.
+    pub fn parse(
+        &mut self,
+        options: &Options,
+        source: &str,
+    ) -> std::result::Result<Module, ParseError> {
+        self.reset(options.stage);
+
+        let lexer = lex::Lexer::new(source, &options.defines);
+        let mut ctx = ParsingContext::new(lexer);
+
+        match ctx.parse(self) {
+            Ok(module) => {
+                if self.errors.is_empty() {
+                    Ok(module)
+                } else {
+                    Err(std::mem::take(&mut self.errors).into())
+                }
+            }
+            Err(e) => {
+                self.errors.push(e);
+                Err(std::mem::take(&mut self.errors).into())
+            }
+        }
+    }
+
+    /// Returns additional information about the parsed shader which might not
+    /// be stored in the [`Module`], see the documentation for
+    /// [`ShaderMetadata`] for more information about the returned data.
+    ///
+    /// # Notes
+    ///
+    /// Following an unsuccessful parsing the state of the returned information
+    /// is undefined, it might contain only partial information about the
+    /// current shader, the previous shader or both.
+    pub const fn metadata(&self) -> &ShaderMetadata {
+        &self.meta
+    }
+}