bench: Represents paths with fs::path instead of std::string

Also uses fs::path quoting in bench printed strings and fixes a
misleading error message.

Originally suggested bitcoin/bitcoin#20744 (comment)

Co-authored-by: Hennadii Stepanov <[email protected]>

Author: ryanofsky

src/bench/bench.cpp

@@ -24,20 +24,19 @@ const std::function<std::vector<const char*>()> G_TEST_COMMAND_LINE_ARGUMENTS{};
 
 namespace {
 
-void GenerateTemplateResults(const std::vector<ankerl::nanobench::Result>& benchmarkResults, const std::string& filename, const char* tpl)
+void GenerateTemplateResults(const std::vector<ankerl::nanobench::Result>& benchmarkResults, const fs::path& file, const char* tpl)
 {
-    if (benchmarkResults.empty() || filename.empty()) {
+    if (benchmarkResults.empty() || file.empty()) {
         // nothing to write, bail out
         return;
     }
-    std::ofstream fout{fs::PathFromString(filename)};
+    std::ofstream fout{file};
     if (fout.is_open()) {
         ankerl::nanobench::render(tpl, benchmarkResults, fout);
+        std::cout << "Created " << file << std::endl;
     } else {
-        std::cout << "Could write to file '" << filename << "'" << std::endl;
+        std::cout << "Could not write to file " << file << std::endl;
     }
-
-    std::cout << "Created '" << filename << "'" << std::endl;
 }
 
 } // namespace

src/bench/bench.h

@@ -5,6 +5,7 @@
 #ifndef BITCOIN_BENCH_BENCH_H
 #define BITCOIN_BENCH_BENCH_H
 
+#include <fs.h>
 #include <util/macros.h>
 
 #include <chrono>
@@ -44,8 +45,8 @@ struct Args {
     bool is_list_only;
     std::chrono::milliseconds min_time;
     std::vector<double> asymptote;
-    std::string output_csv;
-    std::string output_json;
+    fs::path output_csv;
+    fs::path output_json;
     std::string regex_filter;
 };
 

src/bench/bench_bitcoin.cpp

@@ -6,6 +6,7 @@
 
 #include <clientversion.h>
 #include <crypto/sha256.h>
+#include <fs.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 
@@ -108,8 +109,8 @@ int main(int argc, char** argv)
     args.asymptote = parseAsymptote(argsman.GetArg("-asymptote", ""));
     args.is_list_only = argsman.GetBoolArg("-list", false);
     args.min_time = std::chrono::milliseconds(argsman.GetIntArg("-min_time", DEFAULT_MIN_TIME_MS));
-    args.output_csv = argsman.GetArg("-output_csv", "");
-    args.output_json = argsman.GetArg("-output_json", "");
+    args.output_csv = fs::PathFromString(argsman.GetArg("-output_csv", ""));
+    args.output_json = fs::PathFromString(argsman.GetArg("-output_json", ""));
     args.regex_filter = argsman.GetArg("-filter", DEFAULT_BENCH_FILTER);
 
     benchmark::BenchRunner::RunAll(args);