method_meta add uses_backend function

Differential Revision: D69143825

Pull Request resolved: #8198

Author: cmt0

runtime/executor/method_meta.cpp

@@ -228,6 +228,17 @@ Result<int64_t> MethodMeta::memory_planned_buffer_size(size_t index) const {
   return s_plan_->non_const_buffer_sizes()->Get(index + 1);
 }
 
+bool MethodMeta::uses_backend(const char* backend_name) const {
+  const auto delegates = s_plan_->delegates();
+  for (size_t i = 0; i < delegates->size(); i++) {
+    auto delegate = delegates->Get(i);
+    if (strcmp(delegate->id()->c_str(), backend_name) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
 size_t MethodMeta::num_instructions() const {
   const auto chains = s_plan_->chains();
   if (chains == nullptr) {

runtime/executor/method_meta.h

@@ -185,6 +185,14 @@ class MethodMeta final {
    */
   Result<int64_t> memory_planned_buffer_size(size_t index) const;
 
+  /**
+   * Check to see if a backend is used in this method.
+   *
+   * @param[in] backend_name The name of the backend to search for.
+   * @returns true if a backend is used in this method, otherwise false.
+   */
+  bool uses_backend(const char* backend_name) const;
+
   /**
    * Get the number of instructions in this method.
    *

runtime/executor/test/backend_integration_test.cpp

@@ -338,6 +338,10 @@ TEST_P(BackendIntegrationTest, BasicInitSucceeds) {
   Result<Program> program = Program::load(&loader.get());
   ASSERT_EQ(program.error(), Error::Ok);
 
+  auto method_meta = program->method_meta("forward");
+  EXPECT_EQ(method_meta->uses_backend(StubBackend::kName), true);
+  EXPECT_EQ(method_meta->uses_backend("INVALID_BACKEND_NAME"), false);
+
   ManagedMemoryManager mmm(kDefaultNonConstMemBytes, kDefaultRuntimeMemBytes);
   Result<Method> method_res = program->load_method("forward", &mmm.get());
   EXPECT_EQ(method_res.error(), Error::Ok);