[spv-in] Remove providing "perVertexStruct" for certain unnamed inputs

since we probably shouldn't be naming things if they don't have a name
in the input.

As requested here: https://github.com/gfx-rs/wgpu/pull/5227#issuecomment-1936027091

naga/src/front/spv/mod.rs

@@ -5079,7 +5079,7 @@ impl<I: Iterator<Item = u32>> Frontend<I> {
             None
         };
         let span = self.span_from_with_op(start);
-        let mut dec = self.future_decor.remove(&id).unwrap_or_default();
+        let dec = self.future_decor.remove(&id).unwrap_or_default();
 
         let original_ty = self.lookup_type.lookup(type_id)?.handle;
         let mut ty = original_ty;
@@ -5125,17 +5125,6 @@ impl<I: Iterator<Item = u32>> Frontend<I> {
             None => 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(mut space) => {
                 if let crate::AddressSpace::Storage { ref mut access } = space {

naga/tests/out/glsl/quad-vert.main.Vertex.glsl

@@ -17,7 +17,7 @@ vec2 v_uv = vec2(0.0);
 
 vec2 a_uv_1 = vec2(0.0);
 
-gen_gl_PerVertex perVertexStruct = gen_gl_PerVertex(vec4(0.0, 0.0, 0.0, 1.0), 1.0, float[1](0.0), float[1](0.0));
+gen_gl_PerVertex unnamed = gen_gl_PerVertex(vec4(0.0, 0.0, 0.0, 1.0), 1.0, float[1](0.0), float[1](0.0));
 
 vec2 a_pos_1 = vec2(0.0);
 
@@ -29,7 +29,7 @@ void main_1() {
     vec2 _e6 = a_uv_1;
     v_uv = _e6;
     vec2 _e7 = a_pos_1;
-    perVertexStruct.gen_gl_Position = vec4(_e7.x, _e7.y, 0.0, 1.0);
+    unnamed.gen_gl_Position = vec4(_e7.x, _e7.y, 0.0, 1.0);
     return;
 }
 
@@ -40,7 +40,7 @@ void main() {
     a_pos_1 = a_pos;
     main_1();
     vec2 _e7 = v_uv;
-    vec4 _e8 = perVertexStruct.gen_gl_Position;
+    vec4 _e8 = unnamed.gen_gl_Position;
     type_4 _tmp_return = type_4(_e7, _e8);
     _vs2fs_location0 = _tmp_return.member;
     gl_Position = _tmp_return.gen_gl_Position;

naga/tests/out/hlsl/quad-vert.hlsl

@@ -22,7 +22,7 @@ gl_PerVertex Constructgl_PerVertex(float4 arg0, float arg1, float arg2[1], float
 
 static float2 v_uv = (float2)0;
 static float2 a_uv_1 = (float2)0;
-static gl_PerVertex perVertexStruct = Constructgl_PerVertex(float4(0.0, 0.0, 0.0, 1.0), 1.0, (float[1])0, (float[1])0);
+static gl_PerVertex unnamed = Constructgl_PerVertex(float4(0.0, 0.0, 0.0, 1.0), 1.0, (float[1])0, (float[1])0);
 static float2 a_pos_1 = (float2)0;
 
 struct VertexOutput_main {
@@ -35,7 +35,7 @@ void main_1()
     float2 _expr6 = a_uv_1;
     v_uv = _expr6;
     float2 _expr7 = a_pos_1;
-    perVertexStruct.gl_Position = float4(_expr7.x, _expr7.y, 0.0, 1.0);
+    unnamed.gl_Position = float4(_expr7.x, _expr7.y, 0.0, 1.0);
     return;
 }
 
@@ -52,7 +52,7 @@ VertexOutput_main main(float2 a_uv : LOC1, float2 a_pos : LOC0)
     a_pos_1 = a_pos;
     main_1();
     float2 _expr7 = v_uv;
-    float4 _expr8 = perVertexStruct.gl_Position;
+    float4 _expr8 = unnamed.gl_Position;
     const type_4 type_4_ = Constructtype_4(_expr7, _expr8);
     const VertexOutput_main type_4_1 = { type_4_.member, type_4_.gl_Position };
     return type_4_1;

naga/tests/out/msl/quad-vert.msl

@@ -21,13 +21,13 @@ struct type_4 {
 void main_1(
     thread metal::float2& v_uv,
     thread metal::float2& a_uv_1,
-    thread gl_PerVertex& perVertexStruct,
+    thread gl_PerVertex& unnamed,
     thread metal::float2& a_pos_1
 ) {
     metal::float2 _e6 = a_uv_1;
     v_uv = _e6;
     metal::float2 _e7 = a_pos_1;
-    perVertexStruct.gl_Position = metal::float4(_e7.x, _e7.y, 0.0, 1.0);
+    unnamed.gl_Position = metal::float4(_e7.x, _e7.y, 0.0, 1.0);
     return;
 }
 
@@ -44,15 +44,15 @@ vertex main_Output main_(
 ) {
     metal::float2 v_uv = {};
     metal::float2 a_uv_1 = {};
-    gl_PerVertex perVertexStruct = gl_PerVertex {metal::float4(0.0, 0.0, 0.0, 1.0), 1.0, type_3 {}, type_3 {}};
+    gl_PerVertex unnamed = gl_PerVertex {metal::float4(0.0, 0.0, 0.0, 1.0), 1.0, type_3 {}, type_3 {}};
     metal::float2 a_pos_1 = {};
     const auto a_uv = varyings.a_uv;
     const auto a_pos = varyings.a_pos;
     a_uv_1 = a_uv;
     a_pos_1 = a_pos;
-    main_1(v_uv, a_uv_1, perVertexStruct, a_pos_1);
+    main_1(v_uv, a_uv_1, unnamed, a_pos_1);
     metal::float2 _e7 = v_uv;
-    metal::float4 _e8 = perVertexStruct.gl_Position;
+    metal::float4 _e8 = unnamed.gl_Position;
     const auto _tmp = type_4 {_e7, _e8};
     return main_Output { _tmp.member, _tmp.gl_Position };
 }

naga/tests/out/wgsl/quad-vert.wgsl

@@ -12,14 +12,14 @@ struct VertexOutput {
 
 var<private> v_uv: vec2<f32>;
 var<private> a_uv_1: vec2<f32>;
-var<private> perVertexStruct: gl_PerVertex = gl_PerVertex(vec4<f32>(0f, 0f, 0f, 1f), 1f, array<f32, 1>(), array<f32, 1>());
+var<private> unnamed: gl_PerVertex = gl_PerVertex(vec4<f32>(0f, 0f, 0f, 1f), 1f, array<f32, 1>(), array<f32, 1>());
 var<private> a_pos_1: vec2<f32>;
 
 fn main_1() {
     let _e6 = a_uv_1;
     v_uv = _e6;
     let _e7 = a_pos_1;
-    perVertexStruct.gl_Position = vec4<f32>(_e7.x, _e7.y, 0f, 1f);
+    unnamed.gl_Position = vec4<f32>(_e7.x, _e7.y, 0f, 1f);
     return;
 }
 
@@ -29,6 +29,6 @@ fn main(@location(1) a_uv: vec2<f32>, @location(0) a_pos: vec2<f32>) -> VertexOu
     a_pos_1 = a_pos;
     main_1();
     let _e7 = v_uv;
-    let _e8 = perVertexStruct.gl_Position;
+    let _e8 = unnamed.gl_Position;
     return VertexOutput(_e7, _e8);
 }