Fix leak in test, and provide path to remove leak from library (#1169)

* Fix leak in test, and provide path to remove leak from library

* make doc change

README.md

@@ -1243,6 +1243,7 @@ int main(int argc, char** argv) {
       benchmark::RegisterBenchmark(test_input.name(), BM_test, test_input);
   benchmark::Initialize(&argc, argv);
   benchmark::RunSpecifiedBenchmarks();
+  benchmark::Shutdown();
 }
 ```
 

include/benchmark/benchmark.h

@@ -42,6 +42,7 @@ BENCHMARK(BM_StringCopy);
 int main(int argc, char** argv) {
   benchmark::Initialize(&argc, argv);
   benchmark::RunSpecifiedBenchmarks();
+  benchmark::Shutdown();
   return 0;
 }
 
@@ -274,6 +275,7 @@ class BenchmarkReporter;
 class MemoryManager;
 
 void Initialize(int* argc, char** argv);
+void Shutdown();
 
 // Report to stdout all arguments in 'argv' as unrecognized except the first.
 // Returns true there is at least on unrecognized argument (i.e. 'argc' > 1).
@@ -1314,6 +1316,7 @@ class Fixture : public internal::Benchmark {
     ::benchmark::Initialize(&argc, argv);                               \
     if (::benchmark::ReportUnrecognizedArguments(argc, argv)) return 1; \
     ::benchmark::RunSpecifiedBenchmarks();                              \
+    ::benchmark::Shutdown();                                            \
     return 0;                                                           \
   }                                                                     \
   int main(int, char**)

src/benchmark.cc

@@ -548,6 +548,10 @@ void Initialize(int* argc, char** argv) {
   internal::LogLevel() = FLAGS_v;
 }
 
+void Shutdown() {
+  delete internal::global_context;
+}
+
 bool ReportUnrecognizedArguments(int argc, char** argv) {
   for (int i = 1; i < argc; ++i) {
     fprintf(stderr, "%s: error: unrecognized command-line flag: %s\n", argv[0],

test/benchmark_gtest.cc

@@ -143,6 +143,7 @@ TEST(AddCustomContext, Simple) {
               testing::UnorderedElementsAre(testing::Pair("foo", "bar"),
                                             testing::Pair("baz", "qux")));
 
+  delete global_context;
   global_context = nullptr;
 }
 
@@ -155,6 +156,7 @@ TEST(AddCustomContext, DuplicateKey) {
   EXPECT_THAT(*global_context,
               testing::UnorderedElementsAre(testing::Pair("foo", "bar")));
 
+  delete global_context;
   global_context = nullptr;
 }