From 7efa54e41555ec8687a474182fe7574f9b62ad07 Mon Sep 17 00:00:00 2001
From: teoxoy <28601907+teoxoy@users.noreply.github.com>
Date: Mon, 11 Dec 2023 12:57:10 +0100
Subject: [PATCH] [glsl-in] fix swizzle in a global const context

---
 naga/src/front/glsl/context.rs                |  6 ++++-
 naga/tests/in/glsl/const-global-swizzle.frag  | 15 +++++++++++
 .../out/wgsl/const-global-swizzle.frag.wgsl   | 26 +++++++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 naga/tests/in/glsl/const-global-swizzle.frag
 create mode 100644 naga/tests/out/wgsl/const-global-swizzle.frag.wgsl

diff --git a/naga/src/front/glsl/context.rs b/naga/src/front/glsl/context.rs
index 8a5249211e..98ec021a5a 100644
--- a/naga/src/front/glsl/context.rs
+++ b/naga/src/front/glsl/context.rs
@@ -1478,7 +1478,11 @@ impl Index<Handle<Expression>> for Context<'_> {
     type Output = Expression;
 
     fn index(&self, index: Handle<Expression>) -> &Self::Output {
-        &self.expressions[index]
+        if self.is_const {
+            &self.module.const_expressions[index]
+        } else {
+            &self.expressions[index]
+        }
     }
 }
 
diff --git a/naga/tests/in/glsl/const-global-swizzle.frag b/naga/tests/in/glsl/const-global-swizzle.frag
new file mode 100644
index 0000000000..956f33560d
--- /dev/null
+++ b/naga/tests/in/glsl/const-global-swizzle.frag
@@ -0,0 +1,15 @@
+// ISSUE: #4773
+#version 450
+
+#define MIX2(c) c.xy
+
+layout(location = 0) in vec2 v_Uv;
+
+layout(location = 0) out vec4 o_Target;
+
+const vec2 blank = MIX2(vec2(0.0, 1.0));
+
+void main() {
+    vec2 col = MIX2(v_Uv) * blank;
+    o_Target = vec4(col, 0.0, 1.0);
+}
\ No newline at end of file
diff --git a/naga/tests/out/wgsl/const-global-swizzle.frag.wgsl b/naga/tests/out/wgsl/const-global-swizzle.frag.wgsl
new file mode 100644
index 0000000000..dee49c2463
--- /dev/null
+++ b/naga/tests/out/wgsl/const-global-swizzle.frag.wgsl
@@ -0,0 +1,26 @@
+struct FragmentOutput {
+    @location(0) o_Target: vec4<f32>,
+}
+
+const blank: vec2<f32> = vec2<f32>(0f, 1f);
+
+var<private> v_Uv_1: vec2<f32>;
+var<private> o_Target: vec4<f32>;
+
+fn main_1() {
+    var col: vec2<f32>;
+
+    let _e3 = v_Uv_1;
+    col = (_e3.xy * blank);
+    let _e7 = col;
+    o_Target = vec4<f32>(_e7.x, _e7.y, 0f, 1f);
+    return;
+}
+
+@fragment 
+fn main(@location(0) v_Uv: vec2<f32>) -> FragmentOutput {
+    v_Uv_1 = v_Uv;
+    main_1();
+    let _e9 = o_Target;
+    return FragmentOutput(_e9);
+}