validate variable initializer for address spaces (#2513)

Author: teoxoy

src/valid/interface.rs

@@ -33,6 +33,8 @@ pub enum GlobalVariableError {
     ),
     #[error("Initializer doesn't match the variable type")]
     InitializerType,
+    #[error("Initializer can't be used with address space {0:?}")]
+    InitializerNotAllowed(crate::AddressSpace),
     #[error("Storage address space doesn't support write-only access")]
     StorageAddressSpaceWriteOnlyNotSupported,
 }
@@ -572,6 +574,13 @@ impl super::Validator {
         }
 
         if let Some(init) = var.init {
+            match var.space {
+                crate::AddressSpace::Private | crate::AddressSpace::Function => {}
+                _ => {
+                    return Err(GlobalVariableError::InitializerNotAllowed(var.space));
+                }
+            }
+
             let decl_ty = &gctx.types[var.ty].inner;
             let init_ty = mod_info[init].inner_with(gctx.types);
             if !decl_ty.equivalent(init_ty, gctx.types) {

tests/wgsl-errors.rs

@@ -1606,6 +1606,21 @@ fn host_shareable_types() {
     }
 }
 
+#[test]
+fn var_init() {
+    check_validation! {
+        "
+        var<workgroup> initialized: u32 = 0u;
+        ":
+        Err(
+            naga::valid::ValidationError::GlobalVariable {
+                source: naga::valid::GlobalVariableError::InitializerNotAllowed(naga::AddressSpace::WorkGroup),
+                ..
+            },
+        )
+    }
+}
+
 #[test]
 fn misplaced_break_if() {
     check(