Add benchsimulate command

Adds a new command, `benchsimulate`, that starts benchmarking
UpdateLogic() function.

src/openrct2/cmdline/BenchUpdate.cpp

@@ -0,0 +1,119 @@
+/*****************************************************************************
+ * Copyright (c) 2014-2020 OpenRCT2 developers
+ *
+ * For a complete list of all authors, please refer to contributors.md
+ * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
+ *
+ * OpenRCT2 is licensed under the GNU General Public License version 3.
+ *****************************************************************************/
+
+#include "CommandLine.hpp"
+
+#ifdef USE_BENCHMARK
+
+#    include "../Context.h"
+#    include "../GameState.h"
+#    include "../OpenRCT2.h"
+#    include "../platform/platform.h"
+
+#    include <benchmark/benchmark.h>
+#    include <cstdint>
+#    include <iterator>
+#    include <vector>
+
+using namespace OpenRCT2;
+
+static void BM_update(benchmark::State& state, const std::string& filename)
+{
+    std::unique_ptr<IContext> context(CreateContext());
+    if (context->Initialise())
+    {
+        if (!filename.empty() && !context->LoadParkFromFile(filename))
+        {
+            state.SkipWithError("Failed to load file!");
+        }
+
+        for (auto _ : state)
+        {
+            context->GetGameState()->UpdateLogic();
+        }
+        state.SetItemsProcessed(state.iterations());
+    }
+    else
+    {
+        state.SkipWithError("Context initialization failed.");
+    }
+}
+
+static int cmdline_for_bench_sprite_sort(int argc, const char** argv)
+{
+    // Add a baseline test on an empty park
+    benchmark::RegisterBenchmark("baseline", BM_update, std::string{});
+
+    // Google benchmark does stuff to argv. It doesn't modify the pointees,
+    // but it wants to reorder the pointers, so present a copy of them.
+    std::vector<char*> argv_for_benchmark;
+
+    // argv[0] is expected to contain the binary name. It's only for logging purposes, don't bother.
+    argv_for_benchmark.push_back(nullptr);
+
+    // Extract file names from argument list. If there is no such file, consider it benchmark option.
+    for (int i = 0; i < argc; i++)
+    {
+        if (platform_file_exists(argv[i]))
+        {
+            // Register benchmark for sv6 if valid
+            benchmark::RegisterBenchmark(argv[i], BM_update, argv[i]);
+        }
+        else
+        {
+            argv_for_benchmark.push_back((char*)argv[i]);
+        }
+    }
+    // Update argc with all the changes made
+    argc = (int)argv_for_benchmark.size();
+    ::benchmark::Initialize(&argc, &argv_for_benchmark[0]);
+    if (::benchmark::ReportUnrecognizedArguments(argc, &argv_for_benchmark[0]))
+        return -1;
+
+    core_init();
+    gOpenRCT2Headless = true;
+
+    ::benchmark::RunSpecifiedBenchmarks();
+    return 0;
+}
+
+static exitcode_t HandleBenchUpdate(CommandLineArgEnumerator* argEnumerator)
+{
+    const char** argv = (const char**)argEnumerator->GetArguments() + argEnumerator->GetIndex();
+    int32_t argc = argEnumerator->GetCount() - argEnumerator->GetIndex();
+    int32_t result = cmdline_for_bench_sprite_sort(argc, argv);
+    if (result < 0)
+    {
+        return EXITCODE_FAIL;
+    }
+    return EXITCODE_OK;
+}
+
+#else
+static exitcode_t HandleBenchUpdate(CommandLineArgEnumerator* argEnumerator)
+{
+    log_error("Sorry, Google benchmark not enabled in this build");
+    return EXITCODE_FAIL;
+}
+#endif // USE_BENCHMARK
+
+const CommandLineCommand CommandLine::BenchUpdateCommands[]{
+#ifdef USE_BENCHMARK
+    DefineCommand(
+        "",
+        "<file>... [--benchmark_list_tests={true|false}] [--benchmark_filter=<regex>] [--benchmark_min_time=<min_time>] "
+        "[--benchmark_repetitions=<num_repetitions>] [--benchmark_report_aggregates_only={true|false}] "
+        "[--benchmark_format=<console|json|csv>] [--benchmark_out=<filename>] [--benchmark_out_format=<json|console|csv>] "
+        "[--benchmark_color={auto|true|false}] [--benchmark_counters_tabular={true|false}] [--v=<verbosity>]",
+        nullptr, HandleBenchUpdate),
+    CommandTableEnd
+#else
+    DefineCommand("", "*** SORRY NOT ENABLED IN THIS BUILD ***", nullptr, HandleBenchUpdate), CommandTableEnd
+#endif // USE_BENCHMARK
+};

src/openrct2/cmdline/CommandLine.hpp

@@ -118,6 +118,7 @@ namespace CommandLine
     extern const CommandLineCommand SpriteCommands[];
     extern const CommandLineCommand BenchGfxCommands[];
     extern const CommandLineCommand BenchSpriteSortCommands[];
+    extern const CommandLineCommand BenchUpdateCommands[];
     extern const CommandLineCommand SimulateCommands[];
 
     extern const CommandLineExample RootExamples[];

src/openrct2/cmdline/RootCommands.cpp

@@ -140,6 +140,7 @@ const CommandLineCommand CommandLine::RootCommands[]
     DefineSubCommand("sprite",          CommandLine::SpriteCommands           ),
     DefineSubCommand("benchgfx",        CommandLine::BenchGfxCommands         ),
     DefineSubCommand("benchspritesort", CommandLine::BenchSpriteSortCommands  ),
+    DefineSubCommand("benchsimulate",   CommandLine::BenchUpdateCommands      ),
     DefineSubCommand("simulate",        CommandLine::SimulateCommands         ),
     CommandTableEnd
 };