WIP: fix(metal): print [[clip_distances]] before array length

TODO: more cases?

Author: ErichDonGubler

naga/src/back/msl/writer.rs

@@ -7190,10 +7190,19 @@ template <typename A>
                         };
                         let resolved = options.resolve_local_binding(binding, out_mode)?;
                         write!(self.out, "{}{} {}", back::INDENT, ty_name, name)?;
+                        let binding_attr_comes_before_array = matches!(
+                            resolved,
+                            super::ResolvedBinding::BuiltIn(crate::BuiltIn::ClipDistances)
+                        );
+                        if binding_attr_comes_before_array {
+                            resolved.try_fmt(&mut self.out)?;
+                        }
                         if let Some(array_len) = array_len {
                             write!(self.out, " [{array_len}]")?;
                         }
-                        resolved.try_fmt(&mut self.out)?;
+                        if !binding_attr_comes_before_array {
+                            resolved.try_fmt(&mut self.out)?;
+                        }
                         writeln!(self.out, ";")?;
                     }
 

naga/tests/out/msl/wgsl-clip-distances.metal

@@ -15,7 +15,7 @@ struct VertexOutput {
 
 struct main_Output {
     metal::float4 position [[position]];
-    float clip_distances [1] [[clip_distance]];
+    float clip_distances [[clip_distance]] [1];
 };
 vertex main_Output main_(
 ) {