[BugFix][UMA] Protect target registration (apache#13624)

This PR address fixes for UMA target registration.
* Fix the doc issue apache#13304 
* Continues stalled PR apache#12731 

Changes:
* Incorporates all proposed fixes from mentioned [PR apache#12731](apache#12731)
* Address test case concerns and discussions from [PR apache#12731](apache#12731)
* **NEW:** Already exiting target cannot be created, explicit error on this.
* **NEW:** Attributes having special/reserved scope cannot be created explicitly.

It also address proper test cases for all the above.

gallery/tutorial/uma.py

@@ -57,7 +57,7 @@
 #
 
 ######################################################################
-# .. image:: https://raw.githubusercontent.com/apache/tvm-site/main/images/tutorial/uma_vanilla_block_diagram.png
+# .. image:: https://raw.githubusercontent.com/tlc-pack/web-data/main/images/tutorial/uma_vanilla_block_diagram.png
 #   :width: 100%
 #   :alt: A block diagram of Vanilla
 #

python/tvm/relay/backend/contrib/uma/backend.py

@@ -278,11 +278,12 @@ def register(self) -> None:
         """
         registration_func = tvm.get_global_func("relay.backend.contrib.uma.RegisterTarget")
 
-        for name, attr in self._target_attrs:
+        for name, attr in self._target_attrs.items():
             if attr is None:
                 raise ValueError("Target attribute None is not supported.")
-
-        if registration_func(self.target_name, self._target_attrs):
+        # skip if target is already registered
+        if self.target_name not in tvm.target.Target.list_kinds():
+            registration_func(self.target_name, self._target_attrs)
             self._relay_to_relay.register()
             self._relay_to_tir.register()
             self._tir_to_runtime.register()

src/relay/backend/contrib/uma/targets.cc

@@ -31,24 +31,23 @@ namespace tvm {
 namespace relay {
 namespace contrib {
 namespace uma {
-tvm::transform::Pass RelayToTIR(String target_name);
+transform::Pass RelayToTIR(String target_name);
 runtime::Module TIRToRuntime(IRModule mod, Target target);
 }  // namespace uma
 }  // namespace contrib
 }  // namespace relay
 
 TVM_REGISTER_GLOBAL("relay.backend.contrib.uma.RegisterTarget")
     .set_body_typed([](String target_name, Map<String, ObjectRef> attr_options) -> bool {
-      // @todo(cgerum): We probably should get rid of target.register rather sooner than later
-      //               And use a proper registry for uma backends
-      for (const String registered_target_name : ::tvm::TargetKindRegEntry::ListTargetKinds()) {
+      // create only new target and init only once
+      for (const String registered_target_name : TargetKindRegEntry::ListTargetKinds()) {
         if (registered_target_name == target_name) {
-          return false;
+          LOG(FATAL) << "TVM UMA Error: Target is already registered: " << target_name;
         }
       }
 
       auto target_kind =
-          ::tvm::TargetKindRegEntry::RegisterOrGet(target_name)
+          TargetKindRegEntry::RegisterOrGet(target_name)
               .set_name()
               .set_default_device_type(kDLCPU)
               .add_attr_option<Array<String>>("keys")
@@ -58,20 +57,27 @@ TVM_REGISTER_GLOBAL("relay.backend.contrib.uma.RegisterTarget")
               .add_attr_option<Array<String>>("libs")
               .add_attr_option<Target>("host")
               .add_attr_option<Integer>("from_device")
-              .set_attr<FTVMRelayToTIR>(tvm::attr::kRelayToTIR,
+              .set_attr<FTVMRelayToTIR>(attr::kRelayToTIR,
                                         relay::contrib::uma::RelayToTIR(target_name))
               .set_attr<FTVMTIRToRuntime>("TIRToRuntime", relay::contrib::uma::TIRToRuntime);
 
+      // target kind attrs inventory
+      auto kind = TargetKind::Get(target_name).value();
+      auto list_attrs = TargetKindRegEntry::ListTargetKindOptions(kind);
+
       for (auto& attr_option : attr_options) {
         auto option_name = attr_option.first;
         auto default_value = attr_option.second;
+        if (list_attrs.find(option_name) != list_attrs.end()) {
+          LOG(FATAL) << "TVM UMA Error: Attribute is already registered: " << option_name;
+        }
         if (default_value->IsInstance<StringObj>()) {
           target_kind.add_attr_option<String>(option_name, Downcast<String>(default_value));
         } else if (default_value->IsInstance<IntImmNode>()) {
           target_kind.add_attr_option<Integer>(option_name, Downcast<Integer>(default_value));
         } else {
-          LOG(FATAL) << "Only String, Integer, or Bool are supported. Given attribute option type: "
-                     << attr_option.second->GetTypeKey();
+          LOG(FATAL) << "TypeError: Only String, Integer, or Bool are supported. "
+                     << "Given attribute option type: " << attr_option.second->GetTypeKey();
         }
       }
       return true;

tests/python/contrib/test_uma/test_target.py

@@ -64,23 +64,42 @@ def test_uma_target(target_name, target_attrs, target_args):
     [
         ("float_attr", 3.14),
         ("none_attr", None),
+        ("model", "my_model"),
     ],
 )
 def test_invalid_attr_option(attr_name: str, target_attr: Union[str, int, bool, float, None]):
+    registration_func = tvm.get_global_func("relay.backend.contrib.uma.RegisterTarget")
     if target_attr is None:
         # None cannot be caught as TVMError, as it causes a SIGKILL, therefore it must be prevented to be
         # entered into relay.backend.contrib.uma.RegisterTarget at Python level.
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=r"Target attribute None is not supported."):
             uma_backend = VanillaAcceleratorBackend()
             uma_backend._target_attrs = {attr_name: target_attr}
             uma_backend.register()
+    elif "model" in attr_name:
+        target_name = f"{attr_name}_{target_attr}"
+        target_attr = {attr_name: target_attr}
+        with pytest.raises(tvm.TVMError, match=r"Attribute is already registered: .*"):
+            registration_func(target_name, target_attr)
     else:
-        registration_func = tvm.get_global_func("relay.backend.contrib.uma.RegisterTarget")
         target_name = f"{attr_name}_{target_attr}"
         target_attr = {attr_name: target_attr}
-        with pytest.raises(tvm.TVMError, match=r"Only String, Integer, or Bool are supported. .*"):
+        with pytest.raises(TypeError, match=r"Only String, Integer, or Bool are supported. .*"):
             registration_func(target_name, target_attr)
 
 
+@pytest.mark.parametrize(
+    "target_name",
+    [
+        "llvm",
+        "c",
+    ],
+)
+def test_target_duplication(target_name: str):
+    with pytest.raises(tvm.TVMError, match=r"TVM UMA Error: Target is already registered: .*"):
+        registration_func = tvm.get_global_func("relay.backend.contrib.uma.RegisterTarget")
+        registration_func(target_name, {})
+
+
 if __name__ == "__main__":
     tvm.testing.main()