expose comments in Module

Author: Vrixyz

naga/src/front/wgsl/lower/mod.rs

@@ -8,7 +8,7 @@ use crate::front::Typifier;
 use crate::proc::{
     ensure_block_returns, Alignment, ConstantEvaluator, Emitter, Layouter, ResolveContext,
 };
-use crate::{Arena, FastHashMap, FastIndexMap, Handle, Span};
+use crate::{Arena, Comments, FastHashMap, FastIndexMap, Handle, Span};
 
 mod construction;
 mod conversion;
@@ -1090,6 +1090,10 @@ impl<'source, 'temp> Lowerer<'source, 'temp> {
                     let handle = self.r#struct(s, span, &mut ctx)?;
                     ctx.globals
                         .insert(s.name.name, LoweredGlobalDecl::Type(handle));
+                    ctx.module
+                        .comments
+                        .types
+                        .insert(handle, s.comments.iter().map(|s| s.to_string()).collect());
                 }
                 ast::GlobalDeclKind::Type(ref alias) => {
                     let ty = self.resolve_named_ast_type(

naga/src/front/wgsl/parse/lexer.rs

@@ -259,7 +259,7 @@ impl<'a> Lexer<'a> {
         (token, rest)
     }
 
-    pub(in crate::front::wgsl) fn start_byte_offset_and_aggregate_comment(
+    pub(in crate::front::wgsl) fn start_byte_offset_and_aggregate_comment<'b>(
         &'a mut self,
         comments: &mut Vec<Span>,
     ) -> usize {
@@ -268,9 +268,9 @@ impl<'a> Lexer<'a> {
             // Eat all trivia because `next` doesn't eat trailing trivia.
             let (token, rest) = consume_token(self.input, false);
             if let Token::Comment(_) = token {
+                self.input = rest;
                 let next = self.current_byte_offset();
                 comments.push(Span::new(start as u32, next as u32));
-                self.input = rest;
             } else if let Token::Trivia = token {
                 self.input = rest;
             } else {

naga/src/lib.rs

@@ -2263,4 +2263,18 @@ pub struct Module {
     pub functions: Arena<Function>,
     /// Entry points.
     pub entry_points: Vec<EntryPoint>,
+    /// Comments, usually serving as documentation
+    pub comments: Comments,
+}
+
+/// Comments preceding items.
+///
+/// These can be used to generate automated documentation,
+/// IDE hover information or translate shaders with their context comments.
+#[derive(Debug, Default, Clone)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Comments {
+    pub types: FastIndexMap<Handle<Type>, Vec<String>>,
 }

naga/src/valid/handles.rs

@@ -39,6 +39,8 @@ impl super::Validator {
             ref types,
             ref special_types,
             ref global_expressions,
+            // TODO: validate comments (shouldn't have invalid handle or spans ?)
+            ..
         } = module;
 
         // NOTE: Types being first is important. All other forms of validation depend on this.