From 92b7b0d22ab7d8ebf0625fa95f2f12e12a081e8d Mon Sep 17 00:00:00 2001
From: Jim Blandy <jimb@red-bean.com>
Date: Wed, 18 Oct 2023 17:35:41 -0700
Subject: [PATCH] Make validation reject 64-bit floating-point literals.

Make expression validation and constant expression validation reject
`Literal` expressions containing `F64` literals unless the `FLOAT64`
capability is enabled.
---
 src/valid/expression.rs | 17 +++++++++++++++--
 src/valid/type.rs       |  1 +
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/valid/expression.rs b/src/valid/expression.rs
index 765c8e2712..f77844b4b1 100644
--- a/src/valid/expression.rs
+++ b/src/valid/expression.rs
@@ -140,6 +140,8 @@ pub enum ConstExpressionError {
     Type(#[from] ResolveError),
     #[error(transparent)]
     Literal(#[from] LiteralError),
+    #[error(transparent)]
+    Width(#[from] super::r#type::WidthError),
 }
 
 #[derive(Clone, Debug, thiserror::Error)]
@@ -149,6 +151,8 @@ pub enum LiteralError {
     NaN,
     #[error("Float literal is infinite")]
     Infinity,
+    #[error(transparent)]
+    Width(#[from] super::r#type::WidthError),
 }
 
 #[cfg(feature = "validate")]
@@ -188,7 +192,7 @@ impl super::Validator {
 
         match gctx.const_expressions[handle] {
             E::Literal(literal) => {
-                check_literal_value(literal)?;
+                self.validate_literal(literal)?;
             }
             E::Constant(_) | E::ZeroValue(_) => {}
             E::Compose { ref components, ty } => {
@@ -343,7 +347,7 @@ impl super::Validator {
                 ShaderStages::all()
             }
             E::Literal(literal) => {
-                check_literal_value(literal)?;
+                self.validate_literal(literal)?;
                 ShaderStages::all()
             }
             E::Constant(_) | E::ZeroValue(_) => ShaderStages::all(),
@@ -1563,6 +1567,15 @@ impl super::Validator {
             _ => Err(ExpressionError::ExpectedGlobalVariable),
         }
     }
+
+    pub fn validate_literal(&self, literal: crate::Literal) -> Result<(), LiteralError> {
+        let kind = literal.scalar_kind();
+        let width = literal.width();
+        self.check_width(kind, width)?;
+        check_literal_value(literal)?;
+
+        Ok(())
+    }
 }
 
 pub fn check_literal_value(literal: crate::Literal) -> Result<(), LiteralError> {
diff --git a/src/valid/type.rs b/src/valid/type.rs
index c93ae67d74..a5321178c1 100644
--- a/src/valid/type.rs
+++ b/src/valid/type.rs
@@ -129,6 +129,7 @@ pub enum TypeError {
 }
 
 #[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
 pub enum WidthError {
     #[error("The {0:?} scalar width {1} is not supported")]
     Invalid(crate::ScalarKind, crate::Bytes),