From c5636440403c9790ee17d217ed511ce7467048e4 Mon Sep 17 00:00:00 2001
From: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Date: Wed, 16 Feb 2022 10:23:54 +0100
Subject: [PATCH] Introduce the possibility to customize the help printer
 function (#1342)

* introduce the possibility to customize the help printer function

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

* fixed naming convertion, and introduce the option function in the init method

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

* remove the macros to inject the helper function

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

* remove the default implementation, and introduce the nullprt

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
---
 include/benchmark/benchmark.h |  5 ++---
 src/benchmark.cc              | 42 ++++++++++++++++++++---------------
 2 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/include/benchmark/benchmark.h b/include/benchmark/benchmark.h
index 2478daea..79698f69 100644
--- a/include/benchmark/benchmark.h
+++ b/include/benchmark/benchmark.h
@@ -291,7 +291,8 @@ BENCHMARK(BM_test)->Unit(benchmark::kMillisecond);
 namespace benchmark {
 class BenchmarkReporter;
 
-BENCHMARK_EXPORT void Initialize(int* argc, char** argv);
+BENCHMARK_EXPORT void Initialize(int* argc, char** argv,
+                                 void (*HelperPrinterf)() = NULL);
 BENCHMARK_EXPORT void Shutdown();
 
 // Report to stdout all arguments in 'argv' as unrecognized except the first.
@@ -1202,7 +1203,6 @@ class LambdaBenchmark : public Benchmark {
   Lambda lambda_;
 };
 #endif
-
 }  // namespace internal
 
 inline internal::Benchmark* RegisterBenchmark(const char* name,
@@ -1254,7 +1254,6 @@ class Fixture : public internal::Benchmark {
  protected:
   virtual void BenchmarkCase(State&) = 0;
 };
-
 }  // namespace benchmark
 
 // ------------------------------------------------------
diff --git a/src/benchmark.cc b/src/benchmark.cc
index 3c06c85e..d9158432 100644
--- a/src/benchmark.cc
+++ b/src/benchmark.cc
@@ -538,24 +538,29 @@ void AddCustomContext(const std::string& key, const std::string& value) {
 
 namespace internal {
 
+void (*HelperPrintf)();
+
 void PrintUsageAndExit() {
-  fprintf(stdout,
-          "benchmark"
-          " [--benchmark_list_tests={true|false}]\n"
-          "          [--benchmark_filter=<regex>]\n"
-          "          [--benchmark_min_time=<min_time>]\n"
-          "          [--benchmark_repetitions=<num_repetitions>]\n"
-          "          [--benchmark_enable_random_interleaving={true|false}]\n"
-          "          [--benchmark_report_aggregates_only={true|false}]\n"
-          "          [--benchmark_display_aggregates_only={true|false}]\n"
-          "          [--benchmark_format=<console|json|csv>]\n"
-          "          [--benchmark_out=<filename>]\n"
-          "          [--benchmark_out_format=<json|console|csv>]\n"
-          "          [--benchmark_color={auto|true|false}]\n"
-          "          [--benchmark_counters_tabular={true|false}]\n"
-          "          [--benchmark_perf_counters=<counter>,...]\n"
-          "          [--benchmark_context=<key>=<value>,...]\n"
-          "          [--v=<verbosity>]\n");
+  if (HelperPrintf) {
+    HelperPrintf();
+  } else {
+    fprintf(stdout,
+            "benchmark"
+            " [--benchmark_list_tests={true|false}]\n"
+            "          [--benchmark_filter=<regex>]\n"
+            "          [--benchmark_min_time=<min_time>]\n"
+            "          [--benchmark_repetitions=<num_repetitions>]\n"
+            "          [--benchmark_enable_random_interleaving={true|false}]\n"
+            "          [--benchmark_report_aggregates_only={true|false}]\n"
+            "          [--benchmark_display_aggregates_only={true|false}]\n"
+            "          [--benchmark_format=<console|json|csv>]\n"
+            "          [--benchmark_out=<filename>]\n"
+            "          [--benchmark_out_format=<json|console|csv>]\n"
+            "          [--benchmark_color={auto|true|false}]\n"
+            "          [--benchmark_counters_tabular={true|false}]\n"
+            "          [--benchmark_context=<key>=<value>,...]\n"
+            "          [--v=<verbosity>]\n");
+  }
   exit(0);
 }
 
@@ -618,9 +623,10 @@ int InitializeStreams() {
 
 }  // end namespace internal
 
-void Initialize(int* argc, char** argv) {
+void Initialize(int* argc, char** argv, void (*HelperPrintf)()) {
   internal::ParseCommandLineFlags(argc, argv);
   internal::LogLevel() = FLAGS_v;
+  internal::HelperPrintf = HelperPrintf;
 }
 
 void Shutdown() { delete internal::global_context; }