tint/transform: Implement CreateASTTypeFor() for pointers

Change-Id: I83b0bb28194be559e6e60caca6f2dc1871e65743
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/122340
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Ben Clayton <bclayton@chromium.org>

src/tint/transform/transform.cc

@@ -173,6 +173,15 @@ ast::Type Transform::CreateASTTypeFor(CloneContext& ctx, const type::Type* ty) {
     if (auto* s = ty->As<type::Sampler>()) {
         return ctx.dst->ty.sampler(s->kind());
     }
+    if (auto* p = ty->As<type::Pointer>()) {
+        // Note: type::Pointer always has an inferred access, but WGSL only allows an explicit
+        // access in the 'storage' address space.
+        auto address_space = p->AddressSpace();
+        auto access = address_space == builtin::AddressSpace::kStorage
+                          ? p->Access()
+                          : builtin::Access::kUndefined;
+        return ctx.dst->ty.pointer(CreateASTTypeFor(ctx, p->StoreType()), address_space, access);
+    }
     TINT_UNREACHABLE(Transform, ctx.dst->Diagnostics())
         << "Unhandled type: " << ty->TypeInfo().name;
     return ast::Type{};

src/tint/transform/transform_test.cc

@@ -127,5 +127,24 @@ TEST_F(CreateASTTypeForTest, Struct) {
     ast::CheckIdentifier(ast_type_builder.Symbols(), str, "S");
 }
 
+TEST_F(CreateASTTypeForTest, PrivatePointer) {
+    auto ptr = create([](ProgramBuilder& b) {
+        return b.create<type::Pointer>(b.create<type::I32>(), builtin::AddressSpace::kPrivate,
+                                       builtin::Access::kReadWrite);
+    });
+
+    ast::CheckIdentifier(ast_type_builder.Symbols(), ptr, ast::Template("ptr", "private", "i32"));
+}
+
+TEST_F(CreateASTTypeForTest, StorageReadWritePointer) {
+    auto ptr = create([](ProgramBuilder& b) {
+        return b.create<type::Pointer>(b.create<type::I32>(), builtin::AddressSpace::kStorage,
+                                       builtin::Access::kReadWrite);
+    });
+
+    ast::CheckIdentifier(ast_type_builder.Symbols(), ptr,
+                         ast::Template("ptr", "storage", "i32", "read_write"));
+}
+
 }  // namespace
 }  // namespace tint::transform