From 1476ef84ffa2b450c2a2630b0afacf5551662847 Mon Sep 17 00:00:00 2001
From: Igor Shaposhnik <Gordon-F@users.noreply.github.com>
Date: Tue, 4 May 2021 12:59:27 +0000
Subject: [PATCH] [spv-in] Fix empty gl_PerVertex name

---
 src/front/spv/mod.rs    | 14 +++++++++++++-
 tests/out/quad-vert.msl | 10 +++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/front/spv/mod.rs b/src/front/spv/mod.rs
index 052120c81..c7b77830d 100644
--- a/src/front/spv/mod.rs
+++ b/src/front/spv/mod.rs
@@ -363,6 +363,7 @@ struct Assignment {
     value: Handle<crate::Expression>,
 }
 
+#[derive(PartialEq)]
 enum ExtendedClass {
     Global(crate::StorageClass),
     Input,
@@ -3303,7 +3304,7 @@ impl<I: Iterator<Item = u32>> Parser<I> {
         } else {
             None
         };
-        let dec = self.future_decor.remove(&id).unwrap_or_default();
+        let mut dec = self.future_decor.remove(&id).unwrap_or_default();
 
         let original_ty = self.lookup_type.lookup(type_id)?.handle;
         let (effective_ty, is_storage) = match module.types[original_ty].inner {
@@ -3322,6 +3323,17 @@ impl<I: Iterator<Item = u32>> Parser<I> {
             map_storage_class(storage_class)?
         };
 
+        // Fix empty name for gl_PerVertex struct generated by glslang
+        if let crate::TypeInner::Pointer { .. } = module.types[original_ty].inner {
+            if ext_class == ExtendedClass::Input || ext_class == ExtendedClass::Output {
+                if let Some(ref dec_name) = dec.name {
+                    if dec_name.is_empty() {
+                        dec.name = Some("perVertexStruct".to_string())
+                    }
+                }
+            }
+        }
+
         let (inner, var) = match ext_class {
             ExtendedClass::Global(class) => {
                 let storage_access = if is_storage {
diff --git a/tests/out/quad-vert.msl b/tests/out/quad-vert.msl
index 584a9a748..d7363aad4 100644
--- a/tests/out/quad-vert.msl
+++ b/tests/out/quad-vert.msl
@@ -20,12 +20,12 @@ struct type10 {
 void main1(
     thread metal::float2& v_uv,
     thread metal::float2 const& a_uv,
-    thread gl_PerVertex& _,
+    thread gl_PerVertex& perVertexStruct,
     thread metal::float2 const& a_pos
 ) {
     v_uv = a_uv;
     metal::float2 _e13 = a_pos;
-    _.gl_Position = metal::float4(_e13.x, _e13.y, 0.0, 1.0);
+    perVertexStruct.gl_Position = metal::float4(_e13.x, _e13.y, 0.0, 1.0);
     return;
 }
 
@@ -44,13 +44,13 @@ vertex main2Output main2(
 ) {
     metal::float2 v_uv = {};
     metal::float2 a_uv = {};
-    gl_PerVertex _ = {};
+    gl_PerVertex perVertexStruct = {};
     metal::float2 a_pos = {};
     const auto a_uv1 = varyings.a_uv1;
     const auto a_pos1 = varyings.a_pos1;
     a_uv = a_uv1;
     a_pos = a_pos1;
-    main1(v_uv, a_uv, _, a_pos);
-    const auto _tmp = type10 {v_uv, _.gl_Position, _.gl_PointSize, _.gl_ClipDistance};
+    main1(v_uv, a_uv, perVertexStruct, a_pos);
+    const auto _tmp = type10 {v_uv, perVertexStruct.gl_Position, perVertexStruct.gl_PointSize, perVertexStruct.gl_ClipDistance};
     return main2Output { _tmp.member, _tmp.gl_Position1, _tmp.gl_PointSize1, {_tmp.gl_ClipDistance1.inner[0]} };
 }