[naga msl-out] Add padding to end of structs if required

naga/src/back/msl/writer.rs

@@ -4470,6 +4470,16 @@ impl<W: Write> Writer<W> {
                             }
                         }
                     }
+                    if last_offset < span {
+                        let pad = span - last_offset;
+                        writeln!(
+                            self.out,
+                            "{}char _pad{}[{}];",
+                            back::INDENT,
+                            members.len(),
+                            pad
+                        )?;
+                    }
                     writeln!(self.out, "}};")?;
                 }
                 _ => {

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

@@ -12,6 +12,7 @@ struct gl_PerVertex {
     float gl_PointSize;
     type_3 gl_ClipDistance;
     type_3 gl_CullDistance;
+    char _pad4[4];
 };
 struct VertexOutput {
     metal::float2 member;

naga/tests/out/msl/spv-unnamed-gl-per-vertex.msl

@@ -12,6 +12,7 @@ struct type_4 {
     float member_1;
     type_3 member_2;
     type_3 member_3;
+    char _pad4[4];
 };
 
 void function(

naga/tests/out/msl/wgsl-6438-conflicting-idents.msl

@@ -7,6 +7,7 @@ using metal::uint;
 struct OurVertexShaderOutput {
     metal::float4 position;
     metal::float2 texcoord;
+    char _pad2[8];
 };
 
 struct vsInput {

naga/tests/out/msl/wgsl-access.msl

@@ -16,6 +16,7 @@ struct GlobalConst {
 };
 struct AlignedWrapper {
     int value;
+    char _pad1[4];
 };
 struct type_6 {
     metal::float2x2 inner[2];
@@ -35,6 +36,7 @@ struct Bar {
     char _pad4[4];
     type_10 arr;
     type_11 data;
+    char _pad6[8];
 };
 struct Baz {
     metal::float3x2 m;

naga/tests/out/msl/wgsl-atomicCompareExchange.msl

@@ -13,10 +13,12 @@ struct type_4 {
 struct _atomic_compare_exchange_resultSint4_ {
     int old_value;
     bool exchanged;
+    char _pad2[3];
 };
 struct _atomic_compare_exchange_resultUint4_ {
     uint old_value;
     bool exchanged;
+    char _pad2[3];
 };
 
 template <typename A>

naga/tests/out/msl/wgsl-atomicOps.msl

@@ -14,10 +14,12 @@ struct Struct {
 struct _atomic_compare_exchange_resultUint4_ {
     uint old_value;
     bool exchanged;
+    char _pad2[3];
 };
 struct _atomic_compare_exchange_resultSint4_ {
     int old_value;
     bool exchanged;
+    char _pad2[3];
 };
 
 template <typename A>

naga/tests/out/msl/wgsl-bounds-check-restrict.msl

@@ -18,6 +18,7 @@ struct Globals {
     metal::float4 v;
     metal::float3x4 m;
     type_4 d;
+    char _pad4[12];
 };
 
 float index_array(

naga/tests/out/msl/wgsl-bounds-check-zero.msl

@@ -24,6 +24,7 @@ struct Globals {
     metal::float4 v;
     metal::float3x4 m;
     type_4 d;
+    char _pad4[12];
 };
 
 float index_array(

naga/tests/out/msl/wgsl-constructors.msl

@@ -7,6 +7,7 @@ using metal::uint;
 struct Foo {
     metal::float4 a;
     int b;
+    char _pad2[12];
 };
 struct type_6 {
     metal::float2x2 inner[1];

naga/tests/out/msl/wgsl-extra.msl

@@ -12,6 +12,7 @@ struct PushConstants {
 struct FragmentIn {
     metal::float4 color;
     uint primitive_index;
+    char _pad2[12];
 };
 
 struct main_Input {

naga/tests/out/msl/wgsl-fragment-output.msl

@@ -19,6 +19,7 @@ struct FragmentOutputVec2Scalar {
     float scalarf;
     int scalari;
     uint scalaru;
+    char _pad6[4];
 };
 
 struct main_vec4vec3_Output {

naga/tests/out/msl/wgsl-int64.msl

@@ -21,6 +21,7 @@ struct UniformCompatible {
     metal::long3 val_i64_3_;
     metal::long4 val_i64_4_;
     ulong final_value;
+    char _pad12[24];
 };
 struct type_11 {
     ulong inner[2];

naga/tests/out/msl/wgsl-interface.msl

@@ -7,6 +7,7 @@ using metal::uint;
 struct VertexOutput {
     metal::float4 position;
     float _varying;
+    char _pad2[12];
 };
 struct FragmentOutput {
     float depth;

naga/tests/out/msl/wgsl-interpolate.msl

@@ -18,6 +18,7 @@ struct FragmentInput {
     float perspective_centroid;
     float perspective_sample;
     float perspective_center;
+    char _pad12[4];
 };
 
 struct vert_mainOutput {

naga/tests/out/msl/wgsl-interpolate_compat.msl

@@ -18,6 +18,7 @@ struct FragmentInput {
     float perspective_centroid;
     float perspective_sample;
     float perspective_center;
+    char _pad11[4];
 };
 
 struct vert_mainOutput {

naga/tests/out/msl/wgsl-msl-vpt.msl

@@ -13,11 +13,13 @@ struct VertexOutput {
     metal::float4 position;
     metal::float4 color;
     metal::float2 texcoord;
+    char _pad3[8];
 };
 struct VertexInput {
     metal::float4 position;
     metal::float3 normal;
     metal::float2 texcoord;
+    char _pad3[8];
 };
 float unpackFloat32_(uint b0, uint b1, uint b2, uint b3) {
     return as_type<float>(b3 << 24 | b2 << 16 | b1 << 8 | b0);

naga/tests/out/msl/wgsl-overrides-atomicCompareExchangeWeak.msl

@@ -7,6 +7,7 @@ using metal::uint;
 struct _atomic_compare_exchange_resultUint4_ {
     uint old_value;
     bool exchanged;
+    char _pad2[3];
 };
 
 template <typename A>

naga/tests/out/msl/wgsl-padding.msl

@@ -10,6 +10,7 @@ struct S {
 struct Test {
     S a;
     float b;
+    char _pad2[12];
 };
 struct type_2 {
     metal::float3 inner[2];
@@ -17,10 +18,12 @@ struct type_2 {
 struct Test2_ {
     type_2 a;
     float b;
+    char _pad2[12];
 };
 struct Test3_ {
     metal::float4x3 a;
     float b;
+    char _pad2[12];
 };
 
 struct vertex_Output {

tests/tests/wgpu-gpu/shader/struct_layout.rs

@@ -211,7 +211,7 @@ fn create_struct_layout_tests(storage_type: InputStorageType) -> Vec<ShaderTest>
 
     // Test for https://github.com/gfx-rs/wgpu/issues/5262.
     //
-    // The struct is supposed to have a size of 32 and alignment of 16, but on metal, it has size 24.
+    // The struct is supposed to have a size of 32 and alignment of 16.
     for ty in ["f32", "u32", "i32"] {
         let header = format!("struct Inner {{ vec: vec3<{ty}>, scalar1: u32, scalar2: u32 }}");
         let members = String::from("arr: array<Inner, 2>");
@@ -238,8 +238,7 @@ fn create_struct_layout_tests(storage_type: InputStorageType) -> Vec<ShaderTest>
                 &input_values,
                 &[0, 1, 2, 3, 4, 8, 9, 10, 11, 12],
             )
-            .header(header)
-            .failures(Backends::METAL),
+            .header(header),
         );
     }