Print the executable name as part of the context. (#534)

include/benchmark/benchmark.h

@@ -1247,7 +1247,7 @@ class BenchmarkReporter {
     CPUInfo const& cpu_info;
     // The number of chars in the longest benchmark name.
     size_t name_field_width;
-
+    static const char *executable_name;
     Context();
   };
 

src/benchmark.cc

@@ -661,6 +661,7 @@ void PrintUsageAndExit() {
 
 void ParseCommandLineFlags(int* argc, char** argv) {
   using namespace benchmark;
+  BenchmarkReporter::Context::executable_name = argv[0];
   for (int i = 1; i < *argc; ++i) {
     if (ParseBoolFlag(argv[i], "benchmark_list_tests",
                       &FLAGS_benchmark_list_tests) ||

src/json_reporter.cc

@@ -77,6 +77,10 @@ bool JSONReporter::ReportContext(const Context& context) {
   std::string walltime_value = LocalDateTimeString();
   out << indent << FormatKV("date", walltime_value) << ",\n";
 
+  if (Context::executable_name) {
+    out << indent << FormatKV("executable", Context::executable_name) << ",\n";
+  }
+
   CPUInfo const& info = context.cpu_info;
   out << indent << FormatKV("num_cpus", static_cast<int64_t>(info.num_cpus))
       << ",\n";

src/reporter.cc

@@ -37,6 +37,9 @@ void BenchmarkReporter::PrintBasicContext(std::ostream *out,
 
   Out << LocalDateTimeString() << "\n";
 
+  if (context.executable_name)
+    Out << "Running " << context.executable_name << "\n";
+
   const CPUInfo &info = context.cpu_info;
   Out << "Run on (" << info.num_cpus << " X "
       << (info.cycles_per_second / 1000000.0) << " MHz CPU "
@@ -64,6 +67,9 @@ void BenchmarkReporter::PrintBasicContext(std::ostream *out,
 #endif
 }
 
+// No initializer because it's already initialized to NULL.
+const char* BenchmarkReporter::Context::executable_name;
+
 BenchmarkReporter::Context::Context() : cpu_info(CPUInfo::Get()) {}
 
 double BenchmarkReporter::Run::GetAdjustedRealTime() const {

test/reporter_output_test.cc

@@ -17,11 +17,13 @@ static int AddContextCases() {
   AddCases(TC_ConsoleErr,
            {
                {"%int[-/]%int[-/]%int %int:%int:%int$", MR_Default},
+               {"Running .*/reporter_output_test(\\.exe)?$", MR_Next},
                {"Run on \\(%int X %float MHz CPU s\\)", MR_Next},
            });
   AddCases(TC_JSONOut, {{"^\\{", MR_Default},
                         {"\"context\":", MR_Next},
                         {"\"date\": \"", MR_Next},
+                        {"\"executable\": \".*/reporter_output_test(\\.exe)?\",", MR_Next},
                         {"\"num_cpus\": %int,$", MR_Next},
                         {"\"mhz_per_cpu\": %float,$", MR_Next},
                         {"\"cpu_scaling_enabled\": ", MR_Next},