From 6e7d3c4b3e5f0214aa1faeb2839f3f8718d1747a Mon Sep 17 00:00:00 2001
From: Samson <16504129+sagudev@users.noreply.github.com>
Date: Mon, 20 Jan 2025 18:59:11 +0100
Subject: [PATCH] [naga] Explicitly use global const ctx in offset (#6945)

* Fix as_const on expr ctx

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

* fixup

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

---------

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
---
 naga/src/front/wgsl/lower/mod.rs | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/naga/src/front/wgsl/lower/mod.rs b/naga/src/front/wgsl/lower/mod.rs
index eb6f919930..cf050281c0 100644
--- a/naga/src/front/wgsl/lower/mod.rs
+++ b/naga/src/front/wgsl/lower/mod.rs
@@ -372,6 +372,7 @@ pub struct ExpressionContext<'source, 'temp, 'out> {
 }
 
 impl<'source, 'temp, 'out> ExpressionContext<'source, 'temp, 'out> {
+    #[allow(dead_code)]
     fn as_const(&mut self) -> ExpressionContext<'source, '_, '_> {
         ExpressionContext {
             globals: self.globals,
@@ -379,7 +380,21 @@ impl<'source, 'temp, 'out> ExpressionContext<'source, 'temp, 'out> {
             ast_expressions: self.ast_expressions,
             const_typifier: self.const_typifier,
             module: self.module,
-            expr_type: ExpressionContextType::Constant(None),
+            expr_type: ExpressionContextType::Constant(match self.expr_type {
+                ExpressionContextType::Runtime(ref mut local_expression_context)
+                | ExpressionContextType::Constant(Some(ref mut local_expression_context)) => {
+                    Some(LocalExpressionContext {
+                        local_table: local_expression_context.local_table,
+                        function: local_expression_context.function,
+                        block: local_expression_context.block,
+                        emitter: local_expression_context.emitter,
+                        typifier: local_expression_context.typifier,
+                        local_expression_kind_tracker: local_expression_context
+                            .local_expression_kind_tracker,
+                    })
+                }
+                ExpressionContextType::Constant(None) | ExpressionContextType::Override => None,
+            }),
             global_expression_kind_tracker: self.global_expression_kind_tracker,
         }
     }
@@ -2903,7 +2918,7 @@ impl<'source, 'temp> Lowerer<'source, 'temp> {
 
         let offset = args
             .next()
-            .map(|arg| self.expression(arg, &mut ctx.as_const()))
+            .map(|arg| self.expression(arg, &mut ctx.as_global().as_const()))
             .ok()
             .transpose()?;