From 94a317f38774039aae8e8a61779be0a5b6062054 Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Thu, 17 Oct 2024 15:22:05 -0400
Subject: [PATCH] feat(wgsl-in): use more general `enable`-not-set diag. w/
 unimpl. hint

---
 naga/src/front/wgsl/error.rs                  | 31 +++++++++++++++++++
 .../wgsl/parse/directive/enable_extension.rs  |  6 ++--
 naga/src/front/wgsl/parse/mod.rs              | 12 +++++--
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/naga/src/front/wgsl/error.rs b/naga/src/front/wgsl/error.rs
index 622d7e3ea83..5302c1b22f3 100644
--- a/naga/src/front/wgsl/error.rs
+++ b/naga/src/front/wgsl/error.rs
@@ -281,6 +281,10 @@ pub(crate) enum Error<'a> {
         kind: UnimplementedEnableExtension,
         span: Span,
     },
+    EnableExtensionNotEnabled {
+        kind: EnableExtension,
+        span: Span,
+    },
 }
 
 #[derive(Clone, Debug)]
@@ -937,6 +941,33 @@ impl<'a> Error<'a> {
                     kind.tracking_issue_num()
                 )],
             },
+            Error::EnableExtensionNotEnabled { kind, span } => ParseError {
+                message: format!("`{}` enable extension is not enabled", kind.to_ident()),
+                labels: vec![(
+                    span,
+                    format!(
+                        concat!(
+                            "the `{}` enable extension is needed for this functionality, ",
+                            "but it is not currently enabled"
+                        ),
+                        kind.to_ident()
+                    )
+                    .into(),
+                )],
+                notes: if let EnableExtension::Unimplemented(kind) = kind {
+                    vec![format!(
+                        concat!(
+                            "This extension is not yet implemented. ",
+                            "Let Naga maintainers know that you ran into this at ",
+                            "<https://github.com/gfx-rs/wgpu/issues/{}>, ",
+                            "so they can prioritize it!"
+                        ),
+                        kind.tracking_issue_num()
+                    )]
+                } else {
+                    vec![]
+                },
+            },
         }
     }
 }
diff --git a/naga/src/front/wgsl/parse/directive/enable_extension.rs b/naga/src/front/wgsl/parse/directive/enable_extension.rs
index fa5e240278c..ae3115c8a2d 100644
--- a/naga/src/front/wgsl/parse/directive/enable_extension.rs
+++ b/naga/src/front/wgsl/parse/directive/enable_extension.rs
@@ -62,13 +62,13 @@ impl EnableExtension {
     }
 
     /// Maps this [`EnableExtension`] into the sentinel word associated with it in WGSL.
-    pub fn to_ident(self) -> &'static str {
+    pub const fn to_ident(self) -> &'static str {
         match self {
             Self::Implemented(kind) => match kind {},
             Self::Unimplemented(kind) => match kind {
                 UnimplementedEnableExtension::F16 => Self::F16,
-                UnimplementedEnableExtension::ClipDistances => todo!(),
-                UnimplementedEnableExtension::DualSourceBlending => todo!(),
+                UnimplementedEnableExtension::ClipDistances => Self::CLIP_DISTANCES,
+                UnimplementedEnableExtension::DualSourceBlending => Self::DUAL_SOURCE_BLENDING,
             },
         }
     }
diff --git a/naga/src/front/wgsl/parse/mod.rs b/naga/src/front/wgsl/parse/mod.rs
index f5142d07320..05049ac1d73 100644
--- a/naga/src/front/wgsl/parse/mod.rs
+++ b/naga/src/front/wgsl/parse/mod.rs
@@ -1,6 +1,6 @@
 use crate::front::wgsl::error::{Error, ExpectedToken};
 use crate::front::wgsl::parse::directive::enable_extension::{
-    EnableExtension, EnableExtensions, ImplementedEnableExtension,
+    EnableExtension, EnableExtensions, ImplementedEnableExtension, UnimplementedEnableExtension,
 };
 use crate::front::wgsl::parse::directive::DirectiveKind;
 use crate::front::wgsl::parse::lexer::{Lexer, Token};
@@ -669,7 +669,15 @@ impl Parser {
             }
             (Token::Number(res), span) => {
                 let _ = lexer.next();
-                let num = res.map_err(|err| Error::BadNumber(span, err))?;
+                let num = res.map_err(|err| match err {
+                    super::error::NumberError::UnimplementedF16 => {
+                        Error::EnableExtensionNotEnabled {
+                            kind: EnableExtension::Unimplemented(UnimplementedEnableExtension::F16),
+                            span,
+                        }
+                    }
+                    err => Error::BadNumber(span, err),
+                })?;
                 ast::Expression::Literal(ast::Literal::Number(num))
             }
             (Token::Word("RAY_FLAG_NONE"), _) => {