1 files changed, 121 insertions, 0 deletions
diff --git a/third_party/rust/glsl/src/parser.rs b/third_party/rust/glsl/src/parser.rs
new file mode 100644
index 0000000000..d8a33f8594
--- /dev/null
+++ b/third_party/rust/glsl/src/parser.rs
@@ -0,0 +1,121 @@
+//! GLSL parsing.
+//!
+//! This module gives you several functions and types to deal with GLSL parsing, transforming an
+//! input source into an AST. The AST is defined in the [`syntax`] module.
+//!
+//! You want to use the [`Parse`]’s methods to get starting with parsing and pattern match on
+//! the resulting [`Result`]. In case of an error, you can inspect the content of the [`ParseError`]
+//! object in the `Err` variant.
+//!
+//! [`Parse`]: crate::parser::Parse
+//! [`ParseError`]: crate::parser::ParseError
+
+use nom::error::convert_error;
+use nom::Err as NomErr;
+use std::fmt;
+
+use crate::parsers::ParserResult;
+use crate::syntax;
+
+/// A parse error. It contains a [`String`] giving information on the reason why the parser failed.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ParseError {
+  pub info: String,
+}
+
+impl std::error::Error for ParseError {}
+
+impl fmt::Display for ParseError {
+  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    write!(f, "error: {}", self.info)
+  }
+}
+
+/// Run a parser `P` on a given `[&str`] input.
+pub(crate) fn run_parser<P, T>(source: &str, parser: P) -> Result<T, ParseError>
+where
+  P: FnOnce(&str) -> ParserResult<T>,
+{
+  match parser(source) {
+    Ok((_, x)) => Ok(x),
+
+    Err(e) => match e {
+      NomErr::Incomplete(_) => Err(ParseError {
+        info: "incomplete parser".to_owned(),
+      }),
+
+      NomErr::Error(err) | NomErr::Failure(err) => {
+        let info = convert_error(source, err);
+        Err(ParseError { info })
+      }
+    },
+  }
+}
+
+/// Class of types that can be parsed.
+///
+/// This trait exposes the [`Parse::parse`] function that can be used to parse GLSL types.
+///
+/// The methods from this trait are the standard way to parse data into GLSL ASTs.
+pub trait Parse: Sized {
+  /// Parse from a string slice.
+  fn parse<B>(source: B) -> Result<Self, ParseError>
+  where
+    B: AsRef<str>;
+}
+
+/// Macro to implement Parse for a given type.
+macro_rules! impl_parse {
+  ($type_name:ty, $parser_name:ident) => {
+    impl Parse for $type_name {
+      fn parse<B>(source: B) -> Result<Self, ParseError>
+      where
+        B: AsRef<str>,
+      {
+        run_parser(source.as_ref(), $crate::parsers::$parser_name)
+      }
+    }
+  };
+}
+
+impl_parse!(syntax::Identifier, identifier);
+impl_parse!(syntax::TypeSpecifierNonArray, type_specifier_non_array);
+impl_parse!(syntax::TypeSpecifier, type_specifier);
+impl_parse!(syntax::UnaryOp, unary_op);
+impl_parse!(syntax::StructFieldSpecifier, struct_field_specifier);
+impl_parse!(syntax::StructSpecifier, struct_specifier);
+impl_parse!(syntax::StorageQualifier, storage_qualifier);
+impl_parse!(syntax::LayoutQualifier, layout_qualifier);
+impl_parse!(syntax::PrecisionQualifier, precision_qualifier);
+impl_parse!(syntax::InterpolationQualifier, interpolation_qualifier);
+impl_parse!(syntax::TypeQualifier, type_qualifier);
+impl_parse!(syntax::TypeQualifierSpec, type_qualifier_spec);
+impl_parse!(syntax::FullySpecifiedType, fully_specified_type);
+impl_parse!(syntax::ArraySpecifier, array_specifier);
+impl_parse!(syntax::Expr, expr);
+impl_parse!(syntax::Declaration, declaration);
+impl_parse!(syntax::FunctionPrototype, function_prototype);
+impl_parse!(syntax::InitDeclaratorList, init_declarator_list);
+impl_parse!(syntax::SingleDeclaration, single_declaration);
+impl_parse!(syntax::Initializer, initializer);
+impl_parse!(syntax::FunIdentifier, function_identifier);
+impl_parse!(syntax::AssignmentOp, assignment_op);
+impl_parse!(syntax::SimpleStatement, simple_statement);
+impl_parse!(syntax::ExprStatement, expr_statement);
+impl_parse!(syntax::SelectionStatement, selection_statement);
+impl_parse!(syntax::SwitchStatement, switch_statement);
+impl_parse!(syntax::CaseLabel, case_label);
+impl_parse!(syntax::IterationStatement, iteration_statement);
+impl_parse!(syntax::JumpStatement, jump_statement);
+impl_parse!(syntax::Condition, condition);
+impl_parse!(syntax::Statement, statement);
+impl_parse!(syntax::CompoundStatement, compound_statement);
+impl_parse!(syntax::FunctionDefinition, function_definition);
+impl_parse!(syntax::ExternalDeclaration, external_declaration);
+impl_parse!(syntax::TranslationUnit, translation_unit);
+impl_parse!(syntax::Preprocessor, preprocessor);
+impl_parse!(syntax::PreprocessorVersion, pp_version);
+impl_parse!(syntax::PreprocessorVersionProfile, pp_version_profile);
+impl_parse!(syntax::PreprocessorExtensionName, pp_extension_name);
+impl_parse!(syntax::PreprocessorExtensionBehavior, pp_extension_behavior);
+impl_parse!(syntax::PreprocessorExtension, pp_extension);