Merge bitcoin/bitcoin#20744: Use std::filesystem. Remove Boost Filesystem & System

07269321f3 build: remove Boost::system usage (fanquake)
b87f9c5edf build: remove boost::filesystem usage (Kiminuo)
41d7166c8a refactor: replace boost::filesystem with std::filesystem (Kiminuo)
ffc89d1f21 build: add support for std::filesystem (fanquake)

Pull request description:

  This PR replaces our Boost Filesystem usage with [`std::filesystem`](https://en.cppreference.com/w/cpp/filesystem) and includes dropping Boost System as a dependency. It includes a squashed down version of the changes from #19245.

  [A macro has been added](https://github.com/bitcoin/bitcoin/commit/7002c4ade0148c3273659208ae517b79822b289d), modelling how we check for `-latomic` to facilitate linking with `-lstdc++fs` when required. This is  ~GCC < 9.1 & ~Clang < 9.0, however not always. i.e you could be using Clang 7 on top of a GCC 9 installation (i.e Ubuntu Focal) and use `<filesystem>` without passing any additional arguments. I've tested this with GCC 8 on Bionic, Clang 7 on Focal & with Apple Clang 12.0.0 on macOS.

  Guix build:
  ```bash
  bash-5.1# find guix-build-$(git rev-parse --short=12 HEAD)/output/ -type f -print0 | env LC_ALL=C sort -z | xargs -r0 sha256sum
  c1f9b326f9be4140f00cebeae5ff8de428a2fb8ecced539fcc36c53f53bfecf4  guix-build-07269321f38e/output/aarch64-linux-gnu/SHA256SUMS.part
  b44aca3bcf5ea92a3a6c48c24d6f85576f425f59b73528d4d00c20e950cf2128  guix-build-07269321f38e/output/aarch64-linux-gnu/bitcoin-07269321f38e-aarch64-linux-gnu-debug.tar.gz
  27a5553f7bd14797293fc40c5fb131c91e98a61d5481a283f13a1d0497eb5ed8  guix-build-07269321f38e/output/aarch64-linux-gnu/bitcoin-07269321f38e-aarch64-linux-gnu.tar.gz
  99e55a88823f6095864a09c9eaa824e24d9ec527380eb394f751c7205b930f69  guix-build-07269321f38e/output/arm-linux-gnueabihf/SHA256SUMS.part
  b720b2724fa47fde584f58ed3b587f1d1183523540777fd367ab7e582605cfea  guix-build-07269321f38e/output/arm-linux-gnueabihf/bitcoin-07269321f38e-arm-linux-gnueabihf-debug.tar.gz
  c19c247f4e9e0d7f888ac8ba9de1c12d382f48fa828a685d4fe02818a18abd1f  guix-build-07269321f38e/output/arm-linux-gnueabihf/bitcoin-07269321f38e-arm-linux-gnueabihf.tar.gz
  55b49ccb38de03bb95101354a16fd8d2190abede5ccc0d9b00b40c0cd526a2f6  guix-build-07269321f38e/output/arm64-apple-darwin/SHA256SUMS.part
  baa44752470a6be9acae1c2f8fd1b9bc37afb00971787ea11fbaeddc9ab7c4aa  guix-build-07269321f38e/output/arm64-apple-darwin/bitcoin-07269321f38e-arm64-apple-darwin.tar.gz
  ad7df4d8026d5bcce1321cdccc2e1820e8a8bb7e1064ed16e20a7ea354057fd2  guix-build-07269321f38e/output/arm64-apple-darwin/bitcoin-07269321f38e-osx-unsigned.dmg
  f342066dc34a14d67c47779a2413a14633a996e8e7ddca89ae0184e23ef99efd  guix-build-07269321f38e/output/arm64-apple-darwin/bitcoin-07269321f38e-osx-unsigned.tar.gz
  f6905346a5d48f57805fb062d0247ab5007c89047070a0b3125941dd1a2b8aa6  guix-build-07269321f38e/output/dist-archive/bitcoin-07269321f38e.tar.gz
  a1f6c4b2b118dbd89770801f0bcffd2218b82df408cd227e34c40493469bb7a2  guix-build-07269321f38e/output/powerpc64-linux-gnu/SHA256SUMS.part
  ba8359426e523bf013d93579c1bedc57380214c8170a9743b64ec1a8a3bbccbf  guix-build-07269321f38e/output/powerpc64-linux-gnu/bitcoin-07269321f38e-powerpc64-linux-gnu-debug.tar.gz
  b0bb500c274a683ea28ecbc1e8f18c618a9f8acb00045f80ae43c515288402c0  guix-build-07269321f38e/output/powerpc64-linux-gnu/bitcoin-07269321f38e-powerpc64-linux-gnu.tar.gz
  38c85e9589e092cd3aa08996aa383c0ccd5c73208943389741355a6eb7f72537  guix-build-07269321f38e/output/powerpc64le-linux-gnu/SHA256SUMS.part
  50fcba7942ff48d91e84c093fda0affc17e46167fe1d5137c6e14c5c41f289d1  guix-build-07269321f38e/output/powerpc64le-linux-gnu/bitcoin-07269321f38e-powerpc64le-linux-gnu-debug.tar.gz
  fa08ef1ceca072e014faa95ffee945954b2976fa28f90926b87ab0e5f15f8ca5  guix-build-07269321f38e/output/powerpc64le-linux-gnu/bitcoin-07269321f38e-powerpc64le-linux-gnu.tar.gz
  e52dd80a9c306d6aeb544acaa1f4ed560b6b92b5184764a05026d45451aa2e94  guix-build-07269321f38e/output/riscv64-linux-gnu/SHA256SUMS.part
  864e0a16c485b4159cec3ee0a83b046f1b1c3bc821670011c5ac5cd09ddfb91f  guix-build-07269321f38e/output/riscv64-linux-gnu/bitcoin-07269321f38e-riscv64-linux-gnu-debug.tar.gz
  4a061172181322e7ad0cf06405bf74f4c8683eaba3a67ecfd46158cba7627f62  guix-build-07269321f38e/output/riscv64-linux-gnu/bitcoin-07269321f38e-riscv64-linux-gnu.tar.gz
  876d82251853205420dffe7237523fc6ee3d09f78bf74cc03dc71f548446f335  guix-build-07269321f38e/output/x86_64-apple-darwin/SHA256SUMS.part
  3f82b2e62c60eee68e7b8fc28e4792e069e3c2cd780ee2d67290ca422cdbc47c  guix-build-07269321f38e/output/x86_64-apple-darwin/bitcoin-07269321f38e-osx-unsigned.dmg
  4ccdd4c410cac9d627e54ce83ee4816608681735da3cb93c60c5eb70ca86337a  guix-build-07269321f38e/output/x86_64-apple-darwin/bitcoin-07269321f38e-osx-unsigned.tar.gz
  2179d36b2f60e28c15262d4e51f27465b5ae077f60e550345e125683ca611066  guix-build-07269321f38e/output/x86_64-apple-darwin/bitcoin-07269321f38e-osx64.tar.gz
  b377e72fe84b6a982b8d414d60c85e6319523dff50dc852a0ba907f6d850ddd0  guix-build-07269321f38e/output/x86_64-linux-gnu/SHA256SUMS.part
  8547e2f582ce05ae6a6224793b64efb2eb63f2816bf0bed5d53fcc4786274597  guix-build-07269321f38e/output/x86_64-linux-gnu/bitcoin-07269321f38e-x86_64-linux-gnu-debug.tar.gz
  83b64805aa39f31a6fa4c2ed41e029c3be084e6dea06b90fac1ebca5c95bce29  guix-build-07269321f38e/output/x86_64-linux-gnu/bitcoin-07269321f38e-x86_64-linux-gnu.tar.gz
  ```

ACKs for top commit:
  laanwj:
    Code review ACK 07269321f3
  MarcoFalke:
    Concept ACK 07269321f3 🎀
  hebasto:
    ACK 07269321f3

Tree-SHA512: 1f11614467d2013ed799f23c1c14716570f4c798f231671c731a69c7773ef32a0aa2acc69d4ac2f1f176ef6f160f56566c6bd75c9c059a0e82ab4c58d2b2a750

build-aux/m4/ax_boost_filesystem.m4

@@ -1,118 +0,0 @@
-# ===========================================================================
-#   https://www.gnu.org/software/autoconf-archive/ax_boost_filesystem.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_BOOST_FILESYSTEM
-#
-# DESCRIPTION
-#
-#   Test for Filesystem library from the Boost C++ libraries. The macro
-#   requires a preceding call to AX_BOOST_BASE. Further documentation is
-#   available at <http://randspringer.de/boost/index.html>.
-#
-#   This macro calls:
-#
-#     AC_SUBST(BOOST_FILESYSTEM_LIB)
-#
-#   And sets:
-#
-#     HAVE_BOOST_FILESYSTEM
-#
-# LICENSE
-#
-#   Copyright (c) 2009 Thomas Porschberg <thomas@randspringer.de>
-#   Copyright (c) 2009 Michael Tindal
-#   Copyright (c) 2009 Roman Rybalko <libtorrent@romanr.info>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-
-#serial 28
-
-AC_DEFUN([AX_BOOST_FILESYSTEM],
-[
-	AC_ARG_WITH([boost-filesystem],
-	AS_HELP_STRING([--with-boost-filesystem@<:@=special-lib@:>@],
-                   [use the Filesystem library from boost - it is possible to specify a certain library for the linker
-                        e.g. --with-boost-filesystem=boost_filesystem-gcc-mt ]),
-        [
-        if test "$withval" = "no"; then
-			want_boost="no"
-        elif test "$withval" = "yes"; then
-            want_boost="yes"
-            ax_boost_user_filesystem_lib=""
-        else
-		    want_boost="yes"
-		ax_boost_user_filesystem_lib="$withval"
-		fi
-        ],
-        [want_boost="yes"]
-	)
-
-	if test "x$want_boost" = "xyes"; then
-        AC_REQUIRE([AC_PROG_CC])
-		CPPFLAGS_SAVED="$CPPFLAGS"
-		CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-		export CPPFLAGS
-
-		LDFLAGS_SAVED="$LDFLAGS"
-		LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
-		export LDFLAGS
-
-		LIBS_SAVED=$LIBS
-		LIBS="$LIBS $BOOST_SYSTEM_LIB"
-		export LIBS
-
-        AC_CACHE_CHECK(whether the Boost::Filesystem library is available,
-					   ax_cv_boost_filesystem,
-        [AC_LANG_PUSH([C++])
-         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <boost/filesystem/path.hpp>]],
-                                   [[using namespace boost::filesystem;
-                                   path my_path( "foo/bar/data.txt" );
-                                   return 0;]])],
-					       ax_cv_boost_filesystem=yes, ax_cv_boost_filesystem=no)
-         AC_LANG_POP([C++])
-		])
-		if test "x$ax_cv_boost_filesystem" = "xyes"; then
-			AC_DEFINE(HAVE_BOOST_FILESYSTEM,,[define if the Boost::Filesystem library is available])
-            BOOSTLIBDIR=`echo $BOOST_LDFLAGS | sed -e 's/@<:@^\/@:>@*//'`
-            if test "x$ax_boost_user_filesystem_lib" = "x"; then
-                for libextension in `ls -r $BOOSTLIBDIR/libboost_filesystem* 2>/dev/null | sed 's,.*/lib,,' | sed 's,\..*,,'` ; do
-                     ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_FILESYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_FILESYSTEM_LIB) link_filesystem="yes"; break],
-                                 [link_filesystem="no"])
-				done
-                if test "x$link_filesystem" != "xyes"; then
-                for libextension in `ls -r $BOOSTLIBDIR/boost_filesystem* 2>/dev/null | sed 's,.*/,,' | sed -e 's,\..*,,'` ; do
-                     ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_FILESYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_FILESYSTEM_LIB) link_filesystem="yes"; break],
-                                 [link_filesystem="no"])
-				done
-		    fi
-            else
-               for ax_lib in $ax_boost_user_filesystem_lib boost_filesystem-$ax_boost_user_filesystem_lib; do
-				      AC_CHECK_LIB($ax_lib, exit,
-                                   [BOOST_FILESYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_FILESYSTEM_LIB) link_filesystem="yes"; break],
-                                   [link_filesystem="no"])
-                  done
-
-            fi
-            if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the Boost::Filesystem library!)
-            fi
-			if test "x$link_filesystem" != "xyes"; then
-				AC_MSG_ERROR(Could not link against $ax_lib !)
-			fi
-		fi
-
-		CPPFLAGS="$CPPFLAGS_SAVED"
-		LDFLAGS="$LDFLAGS_SAVED"
-		LIBS="$LIBS_SAVED"
-	fi
-])

build-aux/m4/ax_boost_system.m4

@@ -1,121 +0,0 @@
-# ===========================================================================
-#     https://www.gnu.org/software/autoconf-archive/ax_boost_system.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_BOOST_SYSTEM
-#
-# DESCRIPTION
-#
-#   Test for System library from the Boost C++ libraries. The macro requires
-#   a preceding call to AX_BOOST_BASE. Further documentation is available at
-#   <http://randspringer.de/boost/index.html>.
-#
-#   This macro calls:
-#
-#     AC_SUBST(BOOST_SYSTEM_LIB)
-#
-#   And sets:
-#
-#     HAVE_BOOST_SYSTEM
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Thomas Porschberg <thomas@randspringer.de>
-#   Copyright (c) 2008 Michael Tindal
-#   Copyright (c) 2008 Daniel Casimiro <dan.casimiro@gmail.com>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-
-#serial 20
-
-AC_DEFUN([AX_BOOST_SYSTEM],
-[
-	AC_ARG_WITH([boost-system],
-	AS_HELP_STRING([--with-boost-system@<:@=special-lib@:>@],
-                   [use the System library from boost - it is possible to specify a certain library for the linker
-                        e.g. --with-boost-system=boost_system-gcc-mt ]),
-        [
-        if test "$withval" = "no"; then
-			want_boost="no"
-        elif test "$withval" = "yes"; then
-            want_boost="yes"
-            ax_boost_user_system_lib=""
-        else
-		    want_boost="yes"
-		ax_boost_user_system_lib="$withval"
-		fi
-        ],
-        [want_boost="yes"]
-	)
-
-	if test "x$want_boost" = "xyes"; then
-        AC_REQUIRE([AC_PROG_CC])
-        AC_REQUIRE([AC_CANONICAL_BUILD])
-		CPPFLAGS_SAVED="$CPPFLAGS"
-		CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-		export CPPFLAGS
-
-		LDFLAGS_SAVED="$LDFLAGS"
-		LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
-		export LDFLAGS
-
-        AC_CACHE_CHECK(whether the Boost::System library is available,
-					   ax_cv_boost_system,
-        [AC_LANG_PUSH([C++])
-			 CXXFLAGS_SAVE=$CXXFLAGS
-			 CXXFLAGS=
-
-			 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <boost/system/error_code.hpp>]],
-				    [[boost::system::error_category *a = 0;]])],
-                   ax_cv_boost_system=yes, ax_cv_boost_system=no)
-			 CXXFLAGS=$CXXFLAGS_SAVE
-             AC_LANG_POP([C++])
-		])
-		if test "x$ax_cv_boost_system" = "xyes"; then
-			AC_SUBST(BOOST_CPPFLAGS)
-
-			AC_DEFINE(HAVE_BOOST_SYSTEM,,[define if the Boost::System library is available])
-            BOOSTLIBDIR=`echo $BOOST_LDFLAGS | sed -e 's/@<:@^\/@:>@*//'`
-
-			LDFLAGS_SAVE=$LDFLAGS
-            if test "x$ax_boost_user_system_lib" = "x"; then
-                for libextension in `ls -r $BOOSTLIBDIR/libboost_system* 2>/dev/null | sed 's,.*/lib,,' | sed 's,\..*,,'` ; do
-                     ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_SYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_SYSTEM_LIB) link_system="yes"; break],
-                                 [link_system="no"])
-				done
-                if test "x$link_system" != "xyes"; then
-                for libextension in `ls -r $BOOSTLIBDIR/boost_system* 2>/dev/null | sed 's,.*/,,' | sed -e 's,\..*,,'` ; do
-                     ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_SYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_SYSTEM_LIB) link_system="yes"; break],
-                                 [link_system="no"])
-				done
-                fi
-
-            else
-               for ax_lib in $ax_boost_user_system_lib boost_system-$ax_boost_user_system_lib; do
-				      AC_CHECK_LIB($ax_lib, exit,
-                                   [BOOST_SYSTEM_LIB="-l$ax_lib"; AC_SUBST(BOOST_SYSTEM_LIB) link_system="yes"; break],
-                                   [link_system="no"])
-                  done
-
-            fi
-            if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the Boost::System library!)
-            fi
-			if test "x$link_system" = "xno"; then
-				AC_MSG_ERROR(Could not link against $ax_lib !)
-			fi
-		fi
-
-		CPPFLAGS="$CPPFLAGS_SAVED"
-	LDFLAGS="$LDFLAGS_SAVED"
-	fi
-])

build-aux/m4/l_filesystem.m4

@@ -0,0 +1,47 @@
+dnl Copyright (c) 2022 The Bitcoin Core developers
+dnl Distributed under the MIT software license, see the accompanying
+dnl file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# GCC 8.1 and earlier requires -lstdc++fs
+# Clang 8.0.0 (libc++) and earlier requires -lc++fs
+
+m4_define([_CHECK_FILESYSTEM_testbody], [[
+  #include <filesystem>
+
+  namespace fs = std::filesystem;
+
+  int main() {
+    (void)fs::current_path().root_name();
+    return 0;
+  }
+]])
+
+AC_DEFUN([CHECK_FILESYSTEM], [
+
+  AC_LANG_PUSH(C++)
+
+  AC_MSG_CHECKING([whether std::filesystem can be used without link library])
+
+  AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_FILESYSTEM_testbody])],[
+      AC_MSG_RESULT([yes])
+    ],[
+      AC_MSG_RESULT([no])
+      SAVED_LIBS="$LIBS"
+      LIBS="$SAVED_LIBS -lstdc++fs"
+      AC_MSG_CHECKING([whether std::filesystem needs -lstdc++fs])
+      AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_FILESYSTEM_testbody])],[
+          AC_MSG_RESULT([yes])
+        ],[
+          AC_MSG_RESULT([no])
+          AC_MSG_CHECKING([whether std::filesystem needs -lc++fs])
+          LIBS="$SAVED_LIBS -lc++fs"
+          AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_FILESYSTEM_testbody])],[
+            AC_MSG_RESULT([yes])
+        ],[
+            AC_MSG_FAILURE([cannot figure out how to use std::filesystem])
+          ])
+        ])
+    ])
+
+  AC_LANG_POP
+])

build_msvc/bitcoin_config.h.in

@@ -44,15 +44,9 @@
 /* define if the Boost library is available */
 #define HAVE_BOOST /**/
 
-/* define if the Boost::Filesystem library is available */
-#define HAVE_BOOST_FILESYSTEM /**/
-
 /* define if external signer support is enabled (requires Boost::Process) */
 #define ENABLE_EXTERNAL_SIGNER /**/
 
-/* define if the Boost::System library is available */
-#define HAVE_BOOST_SYSTEM /**/
-
 /* define if the Boost::Unit_Test_Framework library is available */
 #define HAVE_BOOST_UNIT_TEST_FRAMEWORK /**/
 

build_msvc/vcpkg.json

@@ -3,7 +3,6 @@
   "version-string": "1",
   "dependencies": [
     "berkeleydb",
-    "boost-filesystem",
     "boost-multi-index",
     "boost-process",
     "boost-signals2",

ci/test/00_setup_env_native_asan.sh

@@ -7,7 +7,7 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_asan
-export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libevent-dev bsdmainutils libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev libqrencode-dev libsqlite3-dev"
+export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libevent-dev bsdmainutils libboost-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev libqrencode-dev libsqlite3-dev"
 export DOCKER_NAME_TAG=ubuntu:22.04
 export NO_DEPENDS=1
 export GOAL="install"

ci/test/00_setup_env_native_fuzz.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export DOCKER_NAME_TAG="ubuntu:20.04"
 export CONTAINER_NAME=ci_native_fuzz
-export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libsqlite3-dev"
+export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-dev libboost-test-dev libsqlite3-dev"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false

ci/test/00_setup_env_native_fuzz_with_valgrind.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export DOCKER_NAME_TAG="ubuntu:20.04"
 export CONTAINER_NAME=ci_native_fuzz_valgrind
-export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libsqlite3-dev valgrind"
+export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-dev libboost-test-dev libsqlite3-dev valgrind"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false

ci/test/00_setup_env_native_valgrind.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export DOCKER_NAME_TAG="ubuntu:20.04"
 export CONTAINER_NAME=ci_native_valgrind
-export PACKAGES="valgrind clang llvm python3-zmq libevent-dev bsdmainutils libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev libsqlite3-dev"
+export PACKAGES="valgrind clang llvm python3-zmq libevent-dev bsdmainutils libboost-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev libsqlite3-dev"
 export USE_VALGRIND=1
 export NO_DEPENDS=1
 export TEST_RUNNER_EXTRA="--nosandbox --exclude rpc_bind,feature_bind_extra"  # Excluded for now, see https://github.com/bitcoin/bitcoin/issues/17765#issuecomment-602068547

configure.ac

@@ -83,6 +83,9 @@ AX_CXX_COMPILE_STDCXX([17], [noext], [mandatory])
 dnl Check if -latomic is required for <std::atomic>
 CHECK_ATOMIC
 
+dnl check if additional link flags are required for std::filesystem
+CHECK_FILESYSTEM
+
 dnl Unless the user specified OBJCXX, force it to be the same as CXX. This ensures
 dnl that we get the same -std flags for both.
 m4_ifdef([AC_PROG_OBJCXX],[
@@ -1404,14 +1407,12 @@ if test "$use_boost" = "yes"; then
   if test "$want_boost" = "no"; then
     AC_MSG_ERROR([only libbitcoinconsensus can be built without Boost])
   fi
-  AX_BOOST_SYSTEM
-  AX_BOOST_FILESYSTEM
 
   if test "$suppress_external_warnings" != "no"; then
     BOOST_CPPFLAGS=SUPPRESS_WARNINGS($BOOST_CPPFLAGS)
   fi
 
-  BOOST_LIBS="$BOOST_LDFLAGS $BOOST_SYSTEM_LIB $BOOST_FILESYSTEM_LIB"
+  BOOST_LIBS="$BOOST_LDFLAGS"
 fi
 
 if test "$use_external_signer" != "no"; then

contrib/valgrind.supp

@@ -118,12 +118,6 @@
    fun:__wcsnlen_sse4_1
    fun:wcsnrtombs
 }
-{
-   Suppress wcsnrtombs warning (remove after removing boost::fs)
-   Memcheck:Cond
-   ...
-   fun:_ZN5boost10filesystem6detail11unique_pathERKNS0_4pathEPNS_6system10error_codeE
-}
 {
    Suppress boost warning
    Memcheck:Leak
@@ -134,21 +128,6 @@
    fun:_ZN5boost9unit_test14unit_test_mainEPFbvEiPPc
    fun:main
 }
-{
-   Suppress boost::filesystem warning (fixed in boost 1.70: https://github.com/boostorg/filesystem/commit/bbe9d1771e5d679b3f10c42a58fc81f7e8c024a9)
-   Memcheck:Cond
-   fun:_ZN5boost10filesystem6detail28directory_iterator_incrementERNS0_18directory_iteratorEPNS_6system10error_codeE
-   ...
-   obj:*/libboost_filesystem.so.*
-}
-{
-   Suppress boost::filesystem warning (could be related: https://stackoverflow.com/questions/9830182/function-boostfilesystemcomplete-being-reported-as-possible-memory-leak-by-v)
-   Memcheck:Leak
-   match-leak-kinds: reachable
-   fun:_Znwm
-   ...
-   fun:_ZN5boost10filesystem8absoluteERKNS0_4pathES3_
-}
 {
    Suppress boost still reachable memory warning
    Memcheck:Leak

depends/packages/boost.mk

@@ -22,7 +22,7 @@ $(package)_toolset_$(host_os)=clang
 else
 $(package)_toolset_$(host_os)=gcc
 endif
-$(package)_config_libraries=filesystem,system,test
+$(package)_config_libraries=test
 $(package)_cxxflags+=-std=c++17
 $(package)_cxxflags_linux=-fPIC
 $(package)_cxxflags_freebsd=-fPIC

doc/build-unix.md

@@ -82,7 +82,7 @@ Build requirements:
 
 Now, you can either build from self-compiled [depends](/depends/README.md) or install the required dependencies:
 
-    sudo apt-get install libevent-dev libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev
+    sudo apt-get install libevent-dev libboost-dev libboost-test-dev
 
 SQLite is required for the descriptor wallet:
 

src/addrdb.cpp

@@ -9,6 +9,7 @@
 #include <chainparams.h>
 #include <clientversion.h>
 #include <cstdint>
+#include <fs.h>
 #include <hash.h>
 #include <logging/timer.h>
 #include <netbase.h>

src/bench/bench.cpp

@@ -8,6 +8,7 @@
 #include <test/util/setup_common.h>
 
 #include <chrono>
+#include <fstream>
 #include <functional>
 #include <iostream>
 #include <map>
@@ -29,7 +30,7 @@ void GenerateTemplateResults(const std::vector<ankerl::nanobench::Result>& bench
         // nothing to write, bail out
         return;
     }
-    fsbridge::ofstream fout{fs::PathFromString(filename)};
+    std::ofstream fout{fs::PathFromString(filename)};
     if (fout.is_open()) {
         ankerl::nanobench::render(tpl, benchmarkResults, fout);
     } else {

src/fs.cpp

@@ -37,7 +37,7 @@ FILE *fopen(const fs::path& p, const char *mode)
 fs::path AbsPathJoin(const fs::path& base, const fs::path& path)
 {
     assert(base.is_absolute());
-    return fs::absolute(path, base);
+    return path.empty() ? base : fs::path(base / path);
 }
 
 #ifndef WIN32
@@ -153,118 +153,4 @@ std::string get_filesystem_error_message(const fs::filesystem_error& e)
 #endif
 }
 
-#ifdef WIN32
-#ifdef __GLIBCXX__
-
-// reference: https://github.com/gcc-mirror/gcc/blob/gcc-7_3_0-release/libstdc%2B%2B-v3/include/std/fstream#L270
-#if defined(__GNUC__) && !defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wswitch"
-#endif
-static std::string openmodeToStr(std::ios_base::openmode mode)
-{
-    switch (mode & ~std::ios_base::ate) {
-    case std::ios_base::out:
-    case std::ios_base::out | std::ios_base::trunc:
-        return "w";
-    case std::ios_base::out | std::ios_base::app:
-    case std::ios_base::app:
-        return "a";
-    case std::ios_base::in:
-        return "r";
-    case std::ios_base::in | std::ios_base::out:
-        return "r+";
-    case std::ios_base::in | std::ios_base::out | std::ios_base::trunc:
-        return "w+";
-    case std::ios_base::in | std::ios_base::out | std::ios_base::app:
-    case std::ios_base::in | std::ios_base::app:
-        return "a+";
-    case std::ios_base::out | std::ios_base::binary:
-    case std::ios_base::out | std::ios_base::trunc | std::ios_base::binary:
-        return "wb";
-    case std::ios_base::out | std::ios_base::app | std::ios_base::binary:
-    case std::ios_base::app | std::ios_base::binary:
-        return "ab";
-    case std::ios_base::in | std::ios_base::binary:
-        return "rb";
-    case std::ios_base::in | std::ios_base::out | std::ios_base::binary:
-        return "r+b";
-    case std::ios_base::in | std::ios_base::out | std::ios_base::trunc | std::ios_base::binary:
-        return "w+b";
-    case std::ios_base::in | std::ios_base::out | std::ios_base::app | std::ios_base::binary:
-    case std::ios_base::in | std::ios_base::app | std::ios_base::binary:
-        return "a+b";
-    default:
-        return std::string();
-    }
-}
-#if defined(__GNUC__) && !defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
-void ifstream::open(const fs::path& p, std::ios_base::openmode mode)
-{
-    close();
-    mode |= std::ios_base::in;
-    m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
-    if (m_file == nullptr) {
-        return;
-    }
-    m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode);
-    rdbuf(&m_filebuf);
-    if (mode & std::ios_base::ate) {
-        seekg(0, std::ios_base::end);
-    }
-}
-
-void ifstream::close()
-{
-    if (m_file != nullptr) {
-        m_filebuf.close();
-        fclose(m_file);
-    }
-    m_file = nullptr;
-}
-
-void ofstream::open(const fs::path& p, std::ios_base::openmode mode)
-{
-    close();
-    mode |= std::ios_base::out;
-    m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
-    if (m_file == nullptr) {
-        return;
-    }
-    m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode);
-    rdbuf(&m_filebuf);
-    if (mode & std::ios_base::ate) {
-        seekp(0, std::ios_base::end);
-    }
-}
-
-void ofstream::close()
-{
-    if (m_file != nullptr) {
-        m_filebuf.close();
-        fclose(m_file);
-    }
-    m_file = nullptr;
-}
-#else // __GLIBCXX__
-
-#if BOOST_VERSION >= 107700
-static_assert(sizeof(*BOOST_FILESYSTEM_C_STR(boost::filesystem::path())) == sizeof(wchar_t),
-#else
-static_assert(sizeof(*boost::filesystem::path().BOOST_FILESYSTEM_C_STR) == sizeof(wchar_t),
-#endif // BOOST_VERSION >= 107700
-    "Warning: This build is using boost::filesystem ofstream and ifstream "
-    "implementations which will fail to open paths containing multibyte "
-    "characters. You should delete this static_assert to ignore this warning, "
-    "or switch to a different C++ standard library like the Microsoft C++ "
-    "Standard Library (where boost uses non-standard extensions to construct "
-    "stream objects with wide filenames), or the GNU libstdc++ library (where "
-    "a more complicated workaround has been implemented above).");
-
-#endif // __GLIBCXX__
-#endif // WIN32
-
 } // fsbridge

src/fs.h

@@ -5,46 +5,42 @@
 #ifndef BITCOIN_FS_H
 #define BITCOIN_FS_H
 
-#include <stdio.h>
-#include <string>
-#if defined WIN32 && defined __GLIBCXX__
-#include <ext/stdio_filebuf.h>
-#endif
-
-#include <boost/filesystem.hpp>
-#include <boost/filesystem/fstream.hpp>
 #include <tinyformat.h>
 
+#include <cstdio>
+#include <filesystem>
+#include <iomanip>
+#include <ios>
+#include <ostream>
+#include <string>
+#include <utility>
+
 /** Filesystem operations and types */
 namespace fs {
 
-using namespace boost::filesystem;
+using namespace std::filesystem;
 
 /**
- * Path class wrapper to prepare application code for transition from
+ * Path class wrapper to block calls to the fs::path(std::string) implicit
- * boost::filesystem library to std::filesystem implementation. The main
+ * constructor and the fs::path::string() method, which have unsafe and
- * purpose of the class is to define fs::path::u8string() and fs::u8path()
+ * unpredictable behavior on Windows (see implementation note in
- * functions not present in boost. It also blocks calls to the
+ * \ref PathToString for details)
- * fs::path(std::string) implicit constructor and the fs::path::string()
- * method, which worked well in the boost::filesystem implementation, but have
- * unsafe and unpredictable behavior on Windows in the std::filesystem
- * implementation (see implementation note in \ref PathToString for details).
  */
-class path : public boost::filesystem::path
+class path : public std::filesystem::path
 {
 public:
-    using boost::filesystem::path::path;
+    using std::filesystem::path::path;
 
     // Allow path objects arguments for compatibility.
-    path(boost::filesystem::path path) : boost::filesystem::path::path(std::move(path)) {}
+    path(std::filesystem::path path) : std::filesystem::path::path(std::move(path)) {}
-    path& operator=(boost::filesystem::path path) { boost::filesystem::path::operator=(std::move(path)); return *this; }
+    path& operator=(std::filesystem::path path) { std::filesystem::path::operator=(std::move(path)); return *this; }
-    path& operator/=(boost::filesystem::path path) { boost::filesystem::path::operator/=(std::move(path)); return *this; }
+    path& operator/=(std::filesystem::path path) { std::filesystem::path::operator/=(std::move(path)); return *this; }
 
     // Allow literal string arguments, which are safe as long as the literals are ASCII.
-    path(const char* c) : boost::filesystem::path(c) {}
+    path(const char* c) : std::filesystem::path(c) {}
-    path& operator=(const char* c) { boost::filesystem::path::operator=(c); return *this; }
+    path& operator=(const char* c) { std::filesystem::path::operator=(c); return *this; }
-    path& operator/=(const char* c) { boost::filesystem::path::operator/=(c); return *this; }
+    path& operator/=(const char* c) { std::filesystem::path::operator/=(c); return *this; }
-    path& append(const char* c) { boost::filesystem::path::append(c); return *this; }
+    path& append(const char* c) { std::filesystem::path::append(c); return *this; }
 
     // Disallow std::string arguments to avoid locale-dependent decoding on windows.
     path(std::string) = delete;
@@ -55,52 +51,48 @@ public:
     // Disallow std::string conversion method to avoid locale-dependent encoding on windows.
     std::string string() const = delete;
 
-    // Define UTF-8 string conversion method not present in boost::filesystem but present in std::filesystem.
+    // Required for path overloads in <fstream>.
-    std::string u8string() const { return boost::filesystem::path::string(); }
+    // See https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=96e0367ead5d8dcac3bec2865582e76e2fbab190
+    path& make_preferred() { std::filesystem::path::make_preferred(); return *this; }
+    path filename() const { return std::filesystem::path::filename(); }
 };
 
-// Define UTF-8 string conversion function not present in boost::filesystem but present in std::filesystem.
+// Disallow implicit std::string conversion for absolute to avoid
-static inline path u8path(const std::string& string)
-{
-    return boost::filesystem::path(string);
-}
-
-// Disallow implicit std::string conversion for system_complete to avoid
 // locale-dependent encoding on windows.
-static inline path system_complete(const path& p)
+static inline path absolute(const path& p)
 {
-    return boost::filesystem::system_complete(p);
+    return std::filesystem::absolute(p);
 }
 
 // Disallow implicit std::string conversion for exists to avoid
 // locale-dependent encoding on windows.
 static inline bool exists(const path& p)
 {
-    return boost::filesystem::exists(p);
+    return std::filesystem::exists(p);
 }
 
 // Allow explicit quoted stream I/O.
 static inline auto quoted(const std::string& s)
 {
-    return boost::io::quoted(s, '&');
+    return std::quoted(s, '"', '&');
 }
 
 // Allow safe path append operations.
 static inline path operator+(path p1, path p2)
 {
-    p1 += static_cast<boost::filesystem::path&&>(p2);
+    p1 += std::move(p2);
     return p1;
 }
 
 // Disallow implicit std::string conversion for copy_file
 // to avoid locale-dependent encoding on Windows.
-static inline void copy_file(const path& from, const path& to, copy_option options)
+static inline bool copy_file(const path& from, const path& to, copy_options options)
 {
-    boost::filesystem::copy_file(from, to, options);
+    return std::filesystem::copy_file(from, to, options);
 }
 
 /**
- * Convert path object to byte string. On POSIX, paths natively are byte
+ * Convert path object to a byte string. On POSIX, paths natively are byte
  * strings, so this is trivial. On Windows, paths natively are Unicode, so an
  * encoding step is necessary. The inverse of \ref PathToString is \ref
  * PathFromString. The strings returned and parsed by these functions can be
@@ -112,7 +104,7 @@ static inline void copy_file(const path& from, const path& to, copy_option optio
  * appropriate to use in applications requiring UTF-8, where
  * fs::path::u8string() and fs::u8path() methods should be used instead. Other
  * applications could require still different encodings. For example, JSON, XML,
- * or URI applications might prefer to use higher level escapes (\uXXXX or
+ * or URI applications might prefer to use higher-level escapes (\uXXXX or
  * &XXXX; or %XX) instead of multibyte encoding. Rust, Python, Java applications
  * may require encoding paths with their respective UTF-8 derivatives WTF-8,
  * PEP-383, and CESU-8 (see https://en.wikipedia.org/wiki/UTF-8#Derivatives).
@@ -133,7 +125,7 @@ static inline std::string PathToString(const path& path)
     return path.u8string();
 #else
     static_assert(std::is_same<path::string_type, std::string>::value, "PathToString not implemented on this platform");
-    return path.boost::filesystem::path::string();
+    return path.std::filesystem::path::string();
 #endif
 }
 
@@ -145,7 +137,7 @@ static inline path PathFromString(const std::string& string)
 #ifdef WIN32
     return u8path(string);
 #else
-    return boost::filesystem::path(string);
+    return std::filesystem::path(string);
 #endif
 }
 } // namespace fs
@@ -186,60 +178,12 @@ namespace fsbridge {
     };
 
     std::string get_filesystem_error_message(const fs::filesystem_error& e);
-
-    // GNU libstdc++ specific workaround for opening UTF-8 paths on Windows.
-    //
-    // On Windows, it is only possible to reliably access multibyte file paths through
-    // `wchar_t` APIs, not `char` APIs. But because the C++ standard doesn't
-    // require ifstream/ofstream `wchar_t` constructors, and the GNU library doesn't
-    // provide them (in contrast to the Microsoft C++ library, see
-    // https://stackoverflow.com/questions/821873/how-to-open-an-stdfstream-ofstream-or-ifstream-with-a-unicode-filename/822032#822032),
-    // Boost is forced to fall back to `char` constructors which may not work properly.
-    //
-    // Work around this issue by creating stream objects with `_wfopen` in
-    // combination with `__gnu_cxx::stdio_filebuf`. This workaround can be removed
-    // with an upgrade to C++17, where streams can be constructed directly from
-    // `std::filesystem::path` objects.
-
-#if defined WIN32 && defined __GLIBCXX__
-    class ifstream : public std::istream
-    {
-    public:
-        ifstream() = default;
-        explicit ifstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in) { open(p, mode); }
-        ~ifstream() { close(); }
-        void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in);
-        bool is_open() { return m_filebuf.is_open(); }
-        void close();
-
-    private:
-        __gnu_cxx::stdio_filebuf<char> m_filebuf;
-        FILE* m_file = nullptr;
-    };
-    class ofstream : public std::ostream
-    {
-    public:
-        ofstream() = default;
-        explicit ofstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out) { open(p, mode); }
-        ~ofstream() { close(); }
-        void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out);
-        bool is_open() { return m_filebuf.is_open(); }
-        void close();
-
-    private:
-        __gnu_cxx::stdio_filebuf<char> m_filebuf;
-        FILE* m_file = nullptr;
-    };
-#else  // !(WIN32 && __GLIBCXX__)
-    typedef fs::ifstream ifstream;
-    typedef fs::ofstream ofstream;
-#endif // WIN32 && __GLIBCXX__
 };
 
 // Disallow path operator<< formatting in tinyformat to avoid locale-dependent
 // encoding on windows.
 namespace tinyformat {
-template<> inline void formatValue(std::ostream&, const char*, const char*, int, const boost::filesystem::path&) = delete;
+template<> inline void formatValue(std::ostream&, const char*, const char*, int, const std::filesystem::path&) = delete;
 template<> inline void formatValue(std::ostream&, const char*, const char*, int, const fs::path&) = delete;
 } // namespace tinyformat
 

src/init.cpp

@@ -72,10 +72,13 @@
 #include <validationinterface.h>
 #include <walletinitinterface.h>
 
+#include <condition_variable>
+#include <cstdint>
+#include <cstdio>
+#include <fstream>
 #include <functional>
 #include <set>
-#include <stdint.h>
+#include <string>
-#include <stdio.h>
 #include <thread>
 #include <vector>
 
@@ -137,7 +140,7 @@ static fs::path GetPidFile(const ArgsManager& args)
 
 [[nodiscard]] static bool CreatePidFile(const ArgsManager& args)
 {
-    fsbridge::ofstream file{GetPidFile(args)};
+    std::ofstream file{GetPidFile(args)};
     if (file) {
 #ifdef WIN32
         tfm::format(file, "%d\n", GetCurrentProcessId());

src/logging.cpp

@@ -3,6 +3,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <fs.h>
 #include <logging.h>
 #include <util/threadnames.h>
 #include <util/string.h>

src/logging.h

@@ -13,6 +13,7 @@
 
 #include <atomic>
 #include <cstdint>
+#include <functional>
 #include <list>
 #include <mutex>
 #include <string>

src/net.cpp

@@ -16,6 +16,7 @@
 #include <compat.h>
 #include <consensus/consensus.h>
 #include <crypto/sha256.h>
+#include <fs.h>
 #include <i2p.h>
 #include <net_permissions.h>
 #include <netaddress.h>

src/qt/guiutil.cpp

@@ -12,6 +12,7 @@
 
 #include <base58.h>
 #include <chainparams.h>
+#include <fs.h>
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <policy/policy.h>
@@ -66,6 +67,10 @@
 
 #include <cassert>
 #include <chrono>
+#include <exception>
+#include <fstream>
+#include <string>
+#include <vector>
 
 #if defined(Q_OS_MAC)
 
@@ -426,7 +431,7 @@ bool openBitcoinConf()
     fs::path pathConfig = GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME));
 
     /* Create the file */
-    fsbridge::ofstream configFile(pathConfig, std::ios_base::app);
+    std::ofstream configFile{pathConfig, std::ios_base::app};
 
     if (!configFile.good())
         return false;
@@ -586,7 +591,7 @@ fs::path static GetAutostartFilePath()
 
 bool GetStartOnSystemStartup()
 {
-    fsbridge::ifstream optionFile(GetAutostartFilePath());
+    std::ifstream optionFile{GetAutostartFilePath()};
     if (!optionFile.good())
         return false;
     // Scan through file for "Hidden=true":
@@ -617,7 +622,7 @@ bool SetStartOnSystemStartup(bool fAutoStart)
 
         fs::create_directories(GetAutostartDir());
 
-        fsbridge::ofstream optionFile(GetAutostartFilePath(), std::ios_base::out | std::ios_base::trunc);
+        std::ofstream optionFile{GetAutostartFilePath(), std::ios_base::out | std::ios_base::trunc};
         if (!optionFile.good())
             return false;
         std::string chain = gArgs.GetChainName();

src/qt/psbtoperationsdialog.cpp

@@ -5,6 +5,7 @@
 #include <qt/psbtoperationsdialog.h>
 
 #include <core_io.h>
+#include <fs.h>
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <node/psbt.h>
@@ -15,7 +16,9 @@
 #include <qt/optionsmodel.h>
 #include <util/strencodings.h>
 
+#include <fstream>
 #include <iostream>
+#include <string>
 
 using node::AnalyzePSBT;
 using node::DEFAULT_MAX_RAW_TX_FEE_RATE;
@@ -158,7 +161,7 @@ void PSBTOperationsDialog::saveTransaction() {
     if (filename.isEmpty()) {
         return;
     }
-    fsbridge::ofstream out{filename.toLocal8Bit().data(), fsbridge::ofstream::out | fsbridge::ofstream::binary};
+    std::ofstream out{filename.toLocal8Bit().data(), std::ofstream::out | std::ofstream::binary};
     out << ssTx.str();
     out.close();
     showStatus(tr("PSBT saved to disk."), StatusLevel::INFO);

src/qt/sendcoinsdialog.cpp

@@ -29,7 +29,10 @@
 #include <wallet/fees.h>
 #include <wallet/wallet.h>
 
+#include <array>
 #include <chrono>
+#include <fstream>
+#include <memory>
 
 #include <QFontMetrics>
 #include <QScrollBar>
@@ -509,7 +512,7 @@ void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
             if (filename.isEmpty()) {
                 return;
             }
-            fsbridge::ofstream out{filename.toLocal8Bit().data(), fsbridge::ofstream::out | fsbridge::ofstream::binary};
+            std::ofstream out{filename.toLocal8Bit().data(), std::ofstream::out | std::ofstream::binary};
             out << ssTx.str();
             out.close();
             Q_EMIT message(tr("PSBT saved"), "PSBT saved to disk", CClientUIInterface::MSG_INFORMATION);

src/qt/walletframe.cpp

@@ -4,6 +4,7 @@
 
 #include <qt/walletframe.h>
 
+#include <fs.h>
 #include <node/ui_interface.h>
 #include <psbt.h>
 #include <qt/guiutil.h>
@@ -14,6 +15,8 @@
 #include <util/system.h>
 
 #include <cassert>
+#include <fstream>
+#include <string>
 
 #include <QApplication>
 #include <QClipboard>
@@ -210,7 +213,7 @@ void WalletFrame::gotoLoadPSBT(bool from_clipboard)
             Q_EMIT message(tr("Error"), tr("PSBT file must be smaller than 100 MiB"), CClientUIInterface::MSG_ERROR);
             return;
         }
-        fsbridge::ifstream in{filename.toLocal8Bit().data(), std::ios::binary};
+        std::ifstream in{filename.toLocal8Bit().data(), std::ios::binary};
         data = std::string(std::istreambuf_iterator<char>{in}, {});
     }
 

src/rpc/request.cpp

@@ -12,6 +12,11 @@
 #include <util/system.h>
 #include <util/strencodings.h>
 
+#include <fstream>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
 /**
  * JSON-RPC protocol.  Bitcoin speaks version 1.0 for maximum compatibility,
  * but uses JSON-RPC 1.1/2.0 standards for parts of the 1.0 standard that were
@@ -83,7 +88,7 @@ bool GenerateAuthCookie(std::string *cookie_out)
     /** the umask determines what permissions are used to create this file -
      * these are set to 077 in init.cpp unless overridden with -sysperms.
      */
-    fsbridge::ofstream file;
+    std::ofstream file;
     fs::path filepath_tmp = GetAuthCookieFile(true);
     file.open(filepath_tmp);
     if (!file.is_open()) {
@@ -107,7 +112,7 @@ bool GenerateAuthCookie(std::string *cookie_out)
 
 bool GetAuthCookie(std::string *cookie_out)
 {
-    fsbridge::ifstream file;
+    std::ifstream file;
     std::string cookie;
     fs::path filepath = GetAuthCookieFile();
     file.open(filepath);

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)

src/util/asmap.cpp

@@ -6,6 +6,7 @@
 
 #include <clientversion.h>
 #include <crypto/common.h>
+#include <fs.h>
 #include <logging.h>
 #include <streams.h>
 

src/util/settings.cpp

@@ -2,11 +2,17 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <fs.h>
 #include <util/settings.h>
 
 #include <tinyformat.h>
 #include <univalue.h>
 
+#include <fstream>
+#include <map>
+#include <string>
+#include <vector>
+
 namespace util {
 namespace {
 
@@ -63,7 +69,7 @@ bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& va
     // Ok for file to not exist
     if (!fs::exists(path)) return true;
 
-    fsbridge::ifstream file;
+    std::ifstream file;
     file.open(path);
     if (!file.is_open()) {
       errors.emplace_back(strprintf("%s. Please check permissions.", fs::PathToString(path)));
@@ -106,7 +112,7 @@ bool WriteSettings(const fs::path& path,
     for (const auto& value : values) {
         out.__pushKV(value.first, value.second);
     }
-    fsbridge::ofstream file;
+    std::ofstream file;
     file.open(path);
     if (file.fail()) {
         errors.emplace_back(strprintf("Error: Unable to open settings file %s for writing", fs::PathToString(path)));

src/util/syscall_sandbox.cpp

@@ -595,6 +595,7 @@ public:
         allowed_syscalls.insert(__NR_readlink);        // read value of a symbolic link
         allowed_syscalls.insert(__NR_rename);          // change the name or location of a file
         allowed_syscalls.insert(__NR_rmdir);           // delete a directory
+        allowed_syscalls.insert(__NR_sendfile);        // transfer data between file descriptors
         allowed_syscalls.insert(__NR_stat);            // get file status
         allowed_syscalls.insert(__NR_statfs);          // get filesystem statistics
         allowed_syscalls.insert(__NR_statx);           // get file status (extended)

src/util/system.cpp

@@ -10,6 +10,7 @@
 #endif // ENABLE_EXTERNAL_SIGNER
 
 #include <chainparamsbase.h>
+#include <fs.h>
 #include <sync.h>
 #include <util/check.h>
 #include <util/getuniquepath.h>
@@ -66,10 +67,15 @@
 #endif
 
 #include <boost/algorithm/string/replace.hpp>
+#include <univalue.h>
+
+#include <fstream>
+#include <map>
+#include <memory>
 #include <optional>
+#include <string>
 #include <thread>
 #include <typeinfo>
-#include <univalue.h>
 
 // Application startup time (used for uptime calculation)
 const int64_t nStartupTime = GetTime();
@@ -146,7 +152,7 @@ bool CheckDiskSpace(const fs::path& dir, uint64_t additional_bytes)
 }
 
 std::streampos GetFileSize(const char* path, std::streamsize max) {
-    fsbridge::ifstream file{path, std::ios::binary};
+    std::ifstream file{path, std::ios::binary};
     file.ignore(max);
     return file.gcount();
 }
@@ -243,7 +249,7 @@ namespace {
 fs::path StripRedundantLastElementsOfPath(const fs::path& path)
 {
     auto result = path;
-    while (fs::PathToString(result.filename()) == ".") {
+    while (result.filename().empty() || fs::PathToString(result.filename()) == ".") {
         result = result.parent_path();
     }
 
@@ -403,7 +409,7 @@ const fs::path& ArgsManager::GetBlocksDirPath() const
     if (!path.empty()) return path;
 
     if (IsArgSet("-blocksdir")) {
-        path = fs::system_complete(fs::PathFromString(GetArg("-blocksdir", "")));
+        path = fs::absolute(fs::PathFromString(GetArg("-blocksdir", "")));
         if (!fs::is_directory(path)) {
             path = "";
             return path;
@@ -415,7 +421,6 @@ const fs::path& ArgsManager::GetBlocksDirPath() const
     path /= fs::PathFromString(BaseParams().DataDir());
     path /= "blocks";
     fs::create_directories(path);
-    path = StripRedundantLastElementsOfPath(path);
     return path;
 }
 
@@ -430,7 +435,7 @@ const fs::path& ArgsManager::GetDataDir(bool net_specific) const
 
     std::string datadir = GetArg("-datadir", "");
     if (!datadir.empty()) {
-        path = fs::system_complete(fs::PathFromString(datadir));
+        path = fs::absolute(StripRedundantLastElementsOfPath(fs::PathFromString(datadir)));
         if (!fs::is_directory(path)) {
             path = "";
             return path;
@@ -808,7 +813,7 @@ fs::path GetDefaultDataDir()
 bool CheckDataDirOption()
 {
     std::string datadir = gArgs.GetArg("-datadir", "");
-    return datadir.empty() || fs::is_directory(fs::system_complete(fs::PathFromString(datadir)));
+    return datadir.empty() || fs::is_directory(fs::absolute(fs::PathFromString(datadir)));
 }
 
 fs::path GetConfigFile(const std::string& confPath)
@@ -898,7 +903,7 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
     }
 
     const std::string confPath = GetArg("-conf", BITCOIN_CONF_FILENAME);
-    fsbridge::ifstream stream(GetConfigFile(confPath));
+    std::ifstream stream{GetConfigFile(confPath)};
 
     // not ok to have a config file specified that cannot be opened
     if (IsArgSet("-conf") && !stream.good()) {
@@ -945,7 +950,7 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
             const size_t default_includes = add_includes({});
 
             for (const std::string& conf_file_name : conf_file_names) {
-                fsbridge::ifstream conf_file_stream(GetConfigFile(conf_file_name));
+                std::ifstream conf_file_stream{GetConfigFile(conf_file_name)};
                 if (conf_file_stream.good()) {
                     if (!ReadConfigStream(conf_file_stream, conf_file_name, error, ignore_invalid_keys)) {
                         return false;
@@ -1069,7 +1074,7 @@ bool RenameOver(fs::path src, fs::path dest)
 }
 
 /**
- * Ignores exceptions thrown by Boost's create_directories if the requested directory exists.
+ * Ignores exceptions thrown by create_directories if the requested directory exists.
  * Specifically handles case where path p exists, but it wasn't possible for the user to
  * write to the parent directory.
  */
@@ -1312,16 +1317,6 @@ void SetupEnvironment()
     // Set the default input/output charset is utf-8
     SetConsoleCP(CP_UTF8);
     SetConsoleOutputCP(CP_UTF8);
-#endif
-    // The path locale is lazy initialized and to avoid deinitialization errors
-    // in multithreading environments, it is set explicitly by the main thread.
-    // A dummy locale is used to extract the internal default locale, used by
-    // fs::path, which is then used to explicitly imbue the path.
-    std::locale loc = fs::path::imbue(std::locale::classic());
-#ifndef WIN32
-    fs::path::imbue(loc);
-#else
-    fs::path::imbue(std::locale(loc, new std::codecvt_utf8_utf16<wchar_t>()));
 #endif
 }
 

src/wallet/bdb.cpp

@@ -3,6 +3,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <fs.h>
 #include <wallet/bdb.h>
 #include <wallet/db.h>
 
@@ -620,12 +621,12 @@ bool BerkeleyDatabase::Backup(const std::string& strDest) const
                     pathDest /= fs::PathFromString(strFile);
 
                 try {
-                    if (fs::equivalent(pathSrc, pathDest)) {
+                    if (fs::exists(pathDest) && fs::equivalent(pathSrc, pathDest)) {
                         LogPrintf("cannot backup to wallet source file %s\n", fs::PathToString(pathDest));
                         return false;
                     }
 
-                    fs::copy_file(pathSrc, pathDest, fs::copy_option::overwrite_if_exists);
+                    fs::copy_file(pathSrc, pathDest, fs::copy_options::overwrite_existing);
                     LogPrintf("copied %s to %s\n", strFile, fs::PathToString(pathDest));
                     return true;
                 } catch (const fs::filesystem_error& e) {

src/wallet/db.cpp

@@ -8,18 +8,22 @@
 #include <logging.h>
 #include <wallet/db.h>
 
+#include <exception>
+#include <fstream>
 #include <string>
+#include <system_error>
+#include <vector>
 
 namespace wallet {
 std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
 {
     std::vector<fs::path> paths;
-    boost::system::error_code ec;
+    std::error_code ec;
 
     for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
         if (ec) {
             if (fs::is_directory(*it)) {
-                it.no_push();
+                it.disable_recursion_pending();
                 LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), fs::PathToString(it->path()));
             } else {
                 LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(it->path()));
@@ -30,11 +34,11 @@ std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
         try {
             const fs::path path{it->path().lexically_relative(wallet_dir)};
 
-            if (it->status().type() == fs::directory_file &&
+            if (it->status().type() == fs::file_type::directory &&
                 (IsBDBFile(BDBDataFile(it->path())) || IsSQLiteFile(SQLiteDataFile(it->path())))) {
                 // Found a directory which contains wallet.dat btree file, add it as a wallet.
                 paths.emplace_back(path);
-            } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBDBFile(it->path())) {
+            } else if (it.depth() == 0 && it->symlink_status().type() == fs::file_type::regular && IsBDBFile(it->path())) {
                 if (it->path().filename() == "wallet.dat") {
                     // Found top-level wallet.dat btree file, add top level directory ""
                     // as a wallet.
@@ -49,7 +53,7 @@ std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
             }
         } catch (const std::exception& e) {
             LogPrintf("%s: Error scanning %s: %s\n", __func__, fs::PathToString(it->path()), e.what());
-            it.no_push();
+            it.disable_recursion_pending();
         }
     }
 
@@ -81,12 +85,12 @@ bool IsBDBFile(const fs::path& path)
 
     // A Berkeley DB Btree file has at least 4K.
     // This check also prevents opening lock files.
-    boost::system::error_code ec;
+    std::error_code ec;
     auto size = fs::file_size(path, ec);
     if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));
     if (size < 4096) return false;
 
-    fsbridge::ifstream file(path, std::ios::binary);
+    std::ifstream file{path, std::ios::binary};
     if (!file.is_open()) return false;
 
     file.seekg(12, std::ios::beg); // Magic bytes start at offset 12
@@ -105,12 +109,12 @@ bool IsSQLiteFile(const fs::path& path)
     if (!fs::exists(path)) return false;
 
     // A SQLite Database file is at least 512 bytes.
-    boost::system::error_code ec;
+    std::error_code ec;
     auto size = fs::file_size(path, ec);
     if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));
     if (size < 512) return false;
 
-    fsbridge::ifstream file(path, std::ios::binary);
+    std::ifstream file{path, std::ios::binary};
     if (!file.is_open()) return false;
 
     // Magic is at beginning and is 16 bytes long

src/wallet/dump.cpp

@@ -4,9 +4,17 @@
 
 #include <wallet/dump.h>
 
+#include <fs.h>
 #include <util/translation.h>
 #include <wallet/wallet.h>
 
+#include <algorithm>
+#include <fstream>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
 namespace wallet {
 static const std::string DUMP_MAGIC = "BITCOIN_CORE_WALLET_DUMP";
 uint32_t DUMP_VERSION = 1;
@@ -26,7 +34,7 @@ bool DumpWallet(CWallet& wallet, bilingual_str& error)
         error = strprintf(_("File %s already exists. If you are sure this is what you want, move it out of the way first."), fs::PathToString(path));
         return false;
     }
-    fsbridge::ofstream dump_file;
+    std::ofstream dump_file;
     dump_file.open(path);
     if (dump_file.fail()) {
         error = strprintf(_("Unable to open %s for writing"), fs::PathToString(path));
@@ -121,7 +129,7 @@ bool CreateFromDump(const std::string& name, const fs::path& wallet_path, biling
         error = strprintf(_("Dump file %s does not exist."), fs::PathToString(dump_path));
         return false;
     }
-    fsbridge::ifstream dump_file(dump_path);
+    std::ifstream dump_file{dump_path};
 
     // Compute the checksum
     CHashWriter hasher(0, 0);

src/wallet/dump.h

@@ -7,6 +7,9 @@
 
 #include <fs.h>
 
+#include <string>
+#include <vector>
+
 struct bilingual_str;
 
 namespace wallet {

src/wallet/load.cpp

@@ -19,6 +19,8 @@
 
 #include <univalue.h>
 
+#include <system_error>
+
 namespace wallet {
 bool VerifyWallets(WalletContext& context)
 {
@@ -27,9 +29,9 @@ bool VerifyWallets(WalletContext& context)
 
     if (args.IsArgSet("-walletdir")) {
         fs::path wallet_dir = fs::PathFromString(args.GetArg("-walletdir", ""));
-        boost::system::error_code error;
+        std::error_code error;
         // The canonical path cleans the path, preventing >1 Berkeley environment instances for the same directory
-        fs::path canonical_wallet_dir = fs::canonical(wallet_dir, error).remove_trailing_separator();
+        fs::path canonical_wallet_dir = fs::canonical(wallet_dir, error);
         if (error || !fs::exists(wallet_dir)) {
             chain.initError(strprintf(_("Specified -walletdir \"%s\" does not exist"), fs::PathToString(wallet_dir)));
             return false;

src/wallet/rpc/backup.cpp

@@ -5,6 +5,7 @@
 #include <chain.h>
 #include <clientversion.h>
 #include <core_io.h>
+#include <fs.h>
 #include <interfaces/chain.h>
 #include <key_io.h>
 #include <merkleblock.h>
@@ -20,8 +21,10 @@
 #include <wallet/rpc/util.h>
 #include <wallet/wallet.h>
 
-#include <stdint.h>
+#include <cstdint>
+#include <fstream>
 #include <tuple>
+#include <string>
 
 #include <boost/algorithm/string.hpp>
 
@@ -521,7 +524,7 @@ RPCHelpMan importwallet()
 
         EnsureWalletIsUnlocked(*pwallet);
 
-        fsbridge::ifstream file;
+        std::ifstream file;
         file.open(fs::u8path(request.params[0].get_str()), std::ios::in | std::ios::ate);
         if (!file.is_open()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");
@@ -729,7 +732,7 @@ RPCHelpMan dumpwallet()
         throw JSONRPCError(RPC_INVALID_PARAMETER, filepath.u8string() + " already exists. If you are sure this is what you want, move it out of the way first");
     }
 
-    fsbridge::ofstream file;
+    std::ofstream file;
     file.open(filepath);
     if (!file.is_open())
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");

src/wallet/test/db_tests.cpp

@@ -2,14 +2,15 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <memory>
-
 #include <boost/test/unit_test.hpp>
 
 #include <fs.h>
 #include <test/util/setup_common.h>
 #include <wallet/bdb.h>
 
+#include <fstream>
+#include <memory>
+#include <string>
 
 namespace wallet {
 BOOST_FIXTURE_TEST_SUITE(db_tests, BasicTestingSetup)
@@ -26,7 +27,7 @@ BOOST_AUTO_TEST_CASE(getwalletenv_file)
     std::string test_name = "test_name.dat";
     const fs::path datadir = gArgs.GetDataDirNet();
     fs::path file_path = datadir / test_name;
-    fs::ofstream f(file_path);
+    std::ofstream f{file_path};
     f.close();
 
     std::string filename;

src/wallet/test/init_test_fixture.cpp

@@ -7,6 +7,9 @@
 #include <util/check.h>
 #include <util/system.h>
 
+#include <fstream>
+#include <string>
+
 #include <wallet/test/init_test_fixture.h>
 
 namespace wallet {
@@ -24,8 +27,8 @@ InitWalletDirTestingSetup::InitWalletDirTestingSetup(const std::string& chainNam
     m_walletdir_path_cases["custom"] = m_datadir / "my_wallets";
     m_walletdir_path_cases["nonexistent"] = m_datadir / "path_does_not_exist";
     m_walletdir_path_cases["file"] = m_datadir / "not_a_directory.dat";
-    m_walletdir_path_cases["trailing"] = m_datadir / "wallets" / sep;
+    m_walletdir_path_cases["trailing"] = m_datadir / ("wallets" + sep);
-    m_walletdir_path_cases["trailing2"] = m_datadir / "wallets" / sep / sep;
+    m_walletdir_path_cases["trailing2"] = m_datadir / ("wallets" + sep + sep);
 
     fs::current_path(m_datadir);
     m_walletdir_path_cases["relative"] = "wallets";
@@ -33,7 +36,7 @@ InitWalletDirTestingSetup::InitWalletDirTestingSetup(const std::string& chainNam
     fs::create_directories(m_walletdir_path_cases["default"]);
     fs::create_directories(m_walletdir_path_cases["custom"]);
     fs::create_directories(m_walletdir_path_cases["relative"]);
-    fs::ofstream f(m_walletdir_path_cases["file"]);
+    std::ofstream f{m_walletdir_path_cases["file"]};
     f.close();
 }
 

src/wallet/test/init_tests.cpp

@@ -73,6 +73,8 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_no_trailing)
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
 
+#ifndef WIN32
+// Windows does not consider "datadir/wallets//" to be a valid directory path.
 BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_no_trailing2)
 {
     SetWalletDir(m_walletdir_path_cases["trailing2"]);
@@ -82,6 +84,7 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_no_trailing2)
     fs::path expected_path = fs::canonical(m_walletdir_path_cases["default"]);
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
+#endif
 
 BOOST_AUTO_TEST_SUITE_END()
 } // namespace wallet

src/wallet/wallet.cpp

@@ -378,7 +378,7 @@ std::shared_ptr<CWallet> RestoreWallet(WalletContext& context, const fs::path& b
     }
 
     auto wallet_file = wallet_path / "wallet.dat";
-    fs::copy_file(backup_file, wallet_file, fs::copy_option::fail_if_exists);
+    fs::copy_file(backup_file, wallet_file, fs::copy_options::none);
 
     auto wallet = LoadWallet(context, wallet_name, load_on_start, options, status, error, warnings);
 
@@ -2651,9 +2651,9 @@ std::unique_ptr<WalletDatabase> MakeWalletDatabase(const std::string& name, cons
     // 4. For backwards compatibility, the name of a data file in -walletdir.
     const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(name));
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
-    if (!(path_type == fs::file_not_found || path_type == fs::directory_file ||
+    if (!(path_type == fs::file_type::not_found || path_type == fs::file_type::directory ||
-          (path_type == fs::symlink_file && fs::is_directory(wallet_path)) ||
+          (path_type == fs::file_type::symlink && fs::is_directory(wallet_path)) ||
-          (path_type == fs::regular_file && fs::PathFromString(name).filename() == fs::PathFromString(name)))) {
+          (path_type == fs::file_type::regular && fs::PathFromString(name).filename() == fs::PathFromString(name)))) {
         error_string = Untranslated(strprintf(
               "Invalid -wallet path '%s'. -wallet path should point to a directory where wallet.dat and "
               "database/log.?????????? files can be stored, a location where such a directory could be created, "

src/wallet/walletdb.cpp

@@ -1105,7 +1105,7 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
 {
     bool exists;
     try {
-        exists = fs::symlink_status(path).type() != fs::file_not_found;
+        exists = fs::symlink_status(path).type() != fs::file_type::not_found;
     } catch (const fs::filesystem_error& e) {
         error = Untranslated(strprintf("Failed to access database path '%s': %s", fs::PathToString(path), fsbridge::get_filesystem_error_message(e)));
         status = DatabaseStatus::FAILED_BAD_PATH;

test/functional/wallet_multiwallet.py

@@ -11,6 +11,7 @@ from threading import Thread
 import os
 import shutil
 import stat
+import sys
 import time
 
 from test_framework.authproxy import JSONRPCException
@@ -141,7 +142,7 @@ class MultiWalletTest(BitcoinTestFramework):
 
         # should raise rpc error if wallet path can't be created
         err_code = -4 if self.options.descriptors else -1
-        assert_raises_rpc_error(err_code, "boost::filesystem::create_director", self.nodes[0].createwallet, "w8/bad")
+        assert_raises_rpc_error(err_code, "filesystem error:" if sys.platform != 'win32' else "create_directories:", self.nodes[0].createwallet, "w8/bad")
 
         # check that all requested wallets were created
         self.stop_node(0)

test/lint/lint-includes.sh

@@ -54,8 +54,6 @@ EXPECTED_BOOST_INCLUDES=(
     boost/algorithm/string/replace.hpp
     boost/algorithm/string/split.hpp
     boost/date_time/posix_time/posix_time.hpp
-    boost/filesystem.hpp
-    boost/filesystem/fstream.hpp
     boost/multi_index/hashed_index.hpp
     boost/multi_index/ordered_index.hpp
     boost/multi_index/sequenced_index.hpp