Add dladdr benchmark.

Bug: 142684469
Test: adb shell /data/benchmarktest64/bionic-benchmarks/bionic-benchmarks --benchmark_filter="BM_dladdr.*"
-------------------------------------------------------------------
Benchmark                         Time             CPU   Iterations
-------------------------------------------------------------------
BM_dladdr_libbase_split        92.6 ns         92.4 ns      6673841
BM_dladdr_libc_printf          8690 ns         8667 ns        80916
BM_dladdr_libdl_dladdr          133 ns          132 ns      5342791
BM_dladdr_local_function       93.0 ns         92.7 ns      7625562

Change-Id: I259dd8f64ccc288835576a2eb08b8b8132777a4b

benchmarks/Android.bp

@@ -29,6 +29,7 @@ cc_defaults {
         "bionic_benchmarks.cpp",
         "atomic_benchmark.cpp",
         "ctype_benchmark.cpp",
+        "dlfcn_benchmark.cpp",
         "get_heap_size_benchmark.cpp",
         "inttypes_benchmark.cpp",
         "malloc_benchmark.cpp",

benchmarks/dlfcn_benchmark.cpp

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/strings.h>
+#include <benchmark/benchmark.h>
+#include <dlfcn.h>
+
+#include "util.h"
+
+void local_function() {}
+
+template<typename F>
+int bm_dladdr(F fun) {
+    const void* addr = reinterpret_cast<void*>(fun);
+    Dl_info info;
+    int res = dladdr(addr, &info);
+    if (res == 0) abort();
+    if (info.dli_fname == nullptr) abort();
+
+    // needed for DoNotOptimize
+    return res;
+}
+BIONIC_TRIVIAL_BENCHMARK(BM_dladdr_libc_printf, bm_dladdr(printf));
+BIONIC_TRIVIAL_BENCHMARK(BM_dladdr_libdl_dladdr, bm_dladdr(dladdr));
+BIONIC_TRIVIAL_BENCHMARK(BM_dladdr_local_function, bm_dladdr(local_function));
+BIONIC_TRIVIAL_BENCHMARK(BM_dladdr_libbase_split, bm_dladdr(android::base::Split));