refactor: replace boost::filesystem with std::filesystem

Warning: Replacing fs::system_complete calls with fs::absolute calls
in this commit may cause minor changes in behaviour because fs::absolute
no longer strips trailing slashes; however these changes are believed to
be safe.

Co-authored-by: Russell Yanofsky <russ@yanofsky.org>
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>

src/test/fs_tests.cpp

@@ -9,6 +9,10 @@
 
 #include <boost/test/unit_test.hpp>
 
+#include <fstream>
+#include <ios>
+#include <string>
+
 BOOST_FIXTURE_TEST_SUITE(fs_tests, BasicTestingSetup)
 
 BOOST_AUTO_TEST_CASE(fsbridge_pathtostring)
@@ -45,37 +49,37 @@ BOOST_AUTO_TEST_CASE(fsbridge_fstream)
     fs::path tmpfile1 = tmpfolder / "fs_tests_₿_🏃";
     fs::path tmpfile2 = tmpfolder / "fs_tests_₿_🏃";
     {
-        fsbridge::ofstream file(tmpfile1);
+        std::ofstream file{tmpfile1};
         file << "bitcoin";
     }
     {
-        fsbridge::ifstream file(tmpfile2);
+        std::ifstream file{tmpfile2};
         std::string input_buffer;
         file >> input_buffer;
         BOOST_CHECK_EQUAL(input_buffer, "bitcoin");
     }
     {
-        fsbridge::ifstream file(tmpfile1, std::ios_base::in | std::ios_base::ate);
+        std::ifstream file{tmpfile1, std::ios_base::in | std::ios_base::ate};
         std::string input_buffer;
         file >> input_buffer;
         BOOST_CHECK_EQUAL(input_buffer, "");
     }
     {
-        fsbridge::ofstream file(tmpfile2, std::ios_base::out | std::ios_base::app);
+        std::ofstream file{tmpfile2, std::ios_base::out | std::ios_base::app};
         file << "tests";
     }
     {
-        fsbridge::ifstream file(tmpfile1);
+        std::ifstream file{tmpfile1};
         std::string input_buffer;
         file >> input_buffer;
         BOOST_CHECK_EQUAL(input_buffer, "bitcointests");
     }
     {
-        fsbridge::ofstream file(tmpfile2, std::ios_base::out | std::ios_base::trunc);
+        std::ofstream file{tmpfile2, std::ios_base::out | std::ios_base::trunc};
         file << "bitcoin";
     }
     {
-        fsbridge::ifstream file(tmpfile1);
+        std::ifstream file{tmpfile1};
         std::string input_buffer;
         file >> input_buffer;
         BOOST_CHECK_EQUAL(input_buffer, "bitcoin");

src/test/fuzz/fuzz.cpp

@@ -4,6 +4,7 @@
 
 #include <test/fuzz/fuzz.h>
 
+#include <fs.h>
 #include <netaddress.h>
 #include <netbase.h>
 #include <test/util/setup_common.h>
@@ -12,9 +13,12 @@
 
 #include <cstdint>
 #include <exception>
+#include <fstream>
 #include <functional>
+#include <map>
 #include <memory>
 #include <string>
+#include <tuple>
 #include <unistd.h>
 #include <vector>
 
@@ -80,7 +84,7 @@ void initialize()
     }
     if (const char* out_path = std::getenv("WRITE_ALL_FUZZ_TARGETS_AND_ABORT")) {
         std::cout << "Writing all fuzz target names to '" << out_path << "'." << std::endl;
-        fsbridge::ofstream out_stream{out_path, std::ios::binary};
+        std::ofstream out_stream{out_path, std::ios::binary};
         for (const auto& t : FuzzTargets()) {
             if (std::get<2>(t.second)) continue;
             out_stream << t.first << std::endl;

src/test/fuzz/utxo_snapshot.cpp

@@ -4,6 +4,7 @@
 
 #include <chainparams.h>
 #include <consensus/validation.h>
+#include <fs.h>
 #include <node/utxo_snapshot.h>
 #include <test/fuzz/FuzzedDataProvider.h>
 #include <test/fuzz/fuzz.h>

src/test/script_tests.cpp

@@ -24,7 +24,8 @@
 #include <script/bitcoinconsensus.h>
 #endif
 
-#include <stdint.h>
+#include <cstdint>
+#include <fstream>
 #include <string>
 #include <vector>
 
@@ -1727,7 +1728,7 @@ BOOST_AUTO_TEST_CASE(script_assets_test)
     bool exists = fs::exists(path);
     BOOST_WARN_MESSAGE(exists, "File $DIR_UNIT_TEST_DATA/script_assets_test.json not found, skipping script_assets_test");
     if (!exists) return;
-    fs::ifstream file(path);
+    std::ifstream file{path};
     BOOST_CHECK(file.is_open());
     file.seekg(0, std::ios::end);
     size_t length = file.tellg();

src/test/settings_tests.cpp

@@ -4,6 +4,7 @@
 
 #include <util/settings.h>
 
+#include <fs.h>
 #include <test/util/setup_common.h>
 #include <test/util/str.h>
 
@@ -13,6 +14,11 @@
 #include <util/strencodings.h>
 #include <util/string.h>
 #include <util/system.h>
+
+#include <fstream>
+#include <map>
+#include <string>
+#include <system_error>
 #include <vector>
 
 inline bool operator==(const util::SettingsValue& a, const util::SettingsValue& b)
@@ -36,7 +42,7 @@ inline std::ostream& operator<<(std::ostream& os, const std::pair<std::string, u
 
 inline void WriteText(const fs::path& path, const std::string& text)
 {
-    fsbridge::ofstream file;
+    std::ofstream file;
     file.open(path);
     file << text;
 }

src/test/streams_tests.cpp

@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <fs.h>
 #include <streams.h>
 #include <test/util/setup_common.h>
 

src/test/util_tests.cpp

@@ -5,6 +5,7 @@
 #include <util/system.h>
 
 #include <clientversion.h>
+#include <fs.h>
 #include <hash.h> // For Hash()
 #include <key.h>  // For CKey
 #include <sync.h>
@@ -70,9 +71,12 @@ BOOST_AUTO_TEST_CASE(util_datadir)
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
 
+#ifndef WIN32
+    // Windows does not consider "datadir/.//" to be a valid directory path.
     args.ForceSetArg("-datadir", fs::PathToString(dd_norm) + "/.//");
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(util_check)