Re: [PATCH] Windows support for std::filesystem

[niXman <i dot nixman at autistici dot org>]

niXman 2017-02-12 20:28:
> Hi,
>
> Tested on i686/x86_64-MinGW-W64
>
> Please test possible regressions on posix platform.

As continuation for: 
https://gcc.gnu.org/ml/libstdc++/2017-02/msg00041.html


Regression on posix platform was fixed.

Tested on i686/x86_64-MinGW-W64 and x86_64-linux-gnu.

Index: libstdc++-v3/src/filesystem/dir.cc
===================================================================
--- libstdc++-v3/src/filesystem/dir.cc	(revision 246136)
+++ libstdc++-v3/src/filesystem/dir.cc	(working copy)
@@ -41,9 +41,10 @@
 #endif
 
 #ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
-# undef opendir
-# define opendir _wopendir
-#endif
+# include "fs-win32.h"
+#else
+# include "fs-posix.h"
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
 
 namespace fs = std::experimental::filesystem;
 
@@ -51,7 +52,7 @@
 {
   _Dir() : dirp(nullptr) { }
 
-  _Dir(DIR* dirp, const fs::path& path) : dirp(dirp), path(path) { }
+  _Dir(os_DIR_t* dirp, const fs::path& path) : dirp(dirp), path(path) { }
 
   _Dir(_Dir&& d)
   : dirp(std::exchange(d.dirp, nullptr)), path(std::move(d.path)),
@@ -60,11 +61,11 @@
 
   _Dir& operator=(_Dir&&) = delete;
 
-  ~_Dir() { if (dirp) ::closedir(dirp); }
+  ~_Dir() { if (dirp) ::os_closedir(dirp); }
 
   bool advance(std::error_code*, directory_options = directory_options::none);
 
-  DIR*			dirp;
+  os_DIR_t*			dirp;
   fs::path		path;
   directory_entry	entry;
   file_type		type = file_type::none;
@@ -87,7 +88,7 @@
     if (ec)
       ec->clear();
 
-    if (DIR* dirp = ::opendir(p.c_str()))
+    if (os_DIR_t* dirp = ::os_opendir(p.c_str()))
       return {dirp, p};
 
     const int err = errno;
@@ -105,7 +106,7 @@
   }
 
   inline fs::file_type
-  get_file_type(const ::dirent& d __attribute__((__unused__)))
+  get_file_type(const ::os_dirent_t& d __attribute__((__unused__)))
   {
 #ifdef _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE
     switch (d.d_type)
@@ -145,13 +146,14 @@
     ec->clear();
 
   int err = std::exchange(errno, 0);
-  const auto entp = readdir(dirp);
+  const auto entp = ::os_readdir(dirp);
   std::swap(errno, err);
 
   if (entp)
     {
       // skip past dot and dot-dot
-      if (!strcmp(entp->d_name, ".") || !strcmp(entp->d_name, ".."))
+      if (!std::char_traits<path::value_type>::compare(entp->d_name, _WS("."), 1) ||
+	    !std::char_traits<path::value_type>::compare(entp->d_name, _WS(".."), 2))
 	return advance(ec, options);
       entry = fs::directory_entry{path / entp->d_name};
       type = get_file_type(*entp);
@@ -239,7 +241,7 @@
                              error_code* ec)
 : _M_options(options), _M_pending(true)
 {
-  if (DIR* dirp = ::opendir(p.c_str()))
+  if (os_DIR_t* dirp = ::os_opendir(p.c_str()))
     {
       auto sp = std::make_shared<_Dir_stack>();
       sp->push(_Dir{ dirp, p });
Index: libstdc++-v3/src/filesystem/fs-posix.h
===================================================================
--- libstdc++-v3/src/filesystem/fs-posix.h	(revision 0)
+++ libstdc++-v3/src/filesystem/fs-posix.h	(working copy)
@@ -0,0 +1,49 @@
+
+// Copyright (C) 2014-2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef _GLIBCXX_EXPERIMENTAL_FS_POSIX_H
+#define _GLIBCXX_EXPERIMENTAL_FS_POSIX_H 1
+
+#define os_DIR_t DIR
+#define os_dirent_t dirent
+#define os_open open
+#define os_opendir opendir
+#define os_closedir closedir
+#define os_readdir readdir
+#define os_stat stat
+#define os_stat_t stat
+#define os_chmod chmod
+#define os_mkdir mkdir
+#define os_getcwd getcwd
+#define os_chdir chdir
+#define os_utimbuf_t utimbuf
+#define os_utime utime
+#define os_remove remove
+#define os_rename rename
+#define os_truncate truncate
+
+#define os_utime utime
+
+#define _WS(x) x
+
+#endif // _GLIBCXX_EXPERIMENTAL_FS_POSIX_H
Index: libstdc++-v3/src/filesystem/fs-win32.h
===================================================================
--- libstdc++-v3/src/filesystem/fs-win32.h	(revision 0)
+++ libstdc++-v3/src/filesystem/fs-win32.h	(working copy)
@@ -0,0 +1,64 @@
+
+// Copyright (C) 2014-2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef _GLIBCXX_EXPERIMENTAL_FS_WIN32_H
+#define _GLIBCXX_EXPERIMENTAL_FS_WIN32_H 1
+
+#define os_DIR_t _WDIR
+#define os_dirent_t _wdirent
+#define os_open _wopen
+#define os_opendir _wopendir
+#define os_closedir _wclosedir
+#define os_readdir _wreaddir
+#define os_stat _wstat
+#define os_stat_t _stat
+#define os_chmod _wchmod
+#define os_mkdir _wmkdir
+#define os_getcwd _wgetcwd
+#define os_chdir _wchdir
+#define os_utimbuf_t _utimbuf
+#define os_utime _wutime
+#define os_remove _wremove
+#define os_rename _wrename
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+inline int _wtruncate(const wchar_t *fname, _off64_t size) {
+  int fd = ::os_open(fname, _O_BINARY|_O_RDWR);
+  if (fd == -1) return fd;
+  int ret = ::ftruncate64(fd, size), err=0;
+  _get_errno(&err);
+  _close(fd);
+  _set_errno(err);
+  return ret;
+}
+
+#define os_truncate _wtruncate
+
+#define os_utime _wutime
+
+#define _WS(x) L##x
+
+#endif // _GLIBCXX_EXPERIMENTAL_FS_WIN32_H
Index: libstdc++-v3/src/filesystem/ops.cc
===================================================================
--- libstdc++-v3/src/filesystem/ops.cc	(revision 246136)
+++ libstdc++-v3/src/filesystem/ops.cc	(working copy)
@@ -56,11 +56,10 @@
 #endif
 
 #ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
-# undef utime
-# define utime _wutime
-# undef chmod
-# define chmod _wchmod
-#endif
+# include "fs-win32.h"
+#else
+# include "fs-posix.h"
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
 
 namespace fs = std::experimental::filesystem;
 
@@ -88,11 +87,7 @@
 
 namespace
 {
-#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
-  inline bool is_dot(wchar_t c) { return c == L'.'; }
-#else
-  inline bool is_dot(char c) { return c == '.'; }
-#endif
+  inline bool is_dot(fs::path::value_type c) { return c == _WS('.'); }
 
   inline bool is_dot(const fs::path& path)
   {
@@ -111,7 +106,7 @@
     void operator()(void* p) const { ::free(p); }
   };
 
-  using char_ptr = std::unique_ptr<char[], free_as_in_malloc>;
+  using char_ptr = std::unique_ptr<fs::path::value_type[], free_as_in_malloc>;
 }
 
 fs::path
@@ -250,7 +245,7 @@
 #ifdef _GLIBCXX_HAVE_SYS_STAT_H
 namespace
 {
-  typedef struct ::stat stat_type;
+  typedef struct ::os_stat_t stat_type;
 
   inline fs::file_type
   make_file_type(const stat_type& st) noexcept
@@ -267,10 +262,12 @@
       return file_type::block;
     else if (S_ISFIFO(st.st_mode))
       return file_type::fifo;
+#ifndef _GLIBCXX_FILESYSTEM_IS_WINDOWS
     else if (S_ISLNK(st.st_mode))
       return file_type::symlink;
     else if (S_ISSOCK(st.st_mode))
       return file_type::socket;
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
 #endif
     return file_type::unknown;
 
@@ -323,7 +320,7 @@
 
     if (to_st == nullptr)
       {
-	if (::stat(to.c_str(), &st1))
+	if (::os_stat(to.c_str(), &st1))
 	  {
 	    int err = errno;
 	    if (!is_not_found_errno(err))
@@ -345,7 +342,7 @@
 
     if (from_st == nullptr)
       {
-	if (::stat(from.c_str(), &st2))
+	if (::os_stat(from.c_str(), &st2))
 	  {
 	    ec.assign(errno, std::generic_category());
 	    return false;
@@ -410,7 +407,7 @@
       int fd;
     };
 
-    CloseFD in = { ::open(from.c_str(), O_RDONLY) };
+    CloseFD in = { ::os_open(from.c_str(), O_RDONLY) };
     if (in.fd == -1)
       {
 	ec.assign(errno, std::generic_category());
@@ -421,7 +418,7 @@
       oflag |= O_TRUNC;
     else
       oflag |= O_EXCL;
-    CloseFD out = { ::open(to.c_str(), oflag, S_IWUSR) };
+    CloseFD out = { ::os_open(to.c_str(), oflag, S_IWUSR) };
     if (out.fd == -1)
       {
 	if (errno == EEXIST && is_set(option, opts::skip_existing))
@@ -436,7 +433,7 @@
 #elif defined _GLIBCXX_USE_FCHMODAT
     if (::fchmodat(AT_FDCWD, to.c_str(), from_st->st_mode, 0))
 #else
-    if (::chmod(to.c_str(), from_st->st_mode))
+    if (::os_chmod(to.c_str(), from_st->st_mode))
 #endif
       {
 	ec.assign(errno, std::generic_category());
@@ -502,16 +499,24 @@
   stat_type from_st, to_st;
   // _GLIBCXX_RESOLVE_LIB_DEFECTS
   // 2681. filesystem::copy() cannot copy symlinks
+#ifndef _GLIBCXX_FILESYSTEM_IS_WINDOWS
   if (use_lstat || copy_symlinks
       ? ::lstat(from.c_str(), &from_st)
       : ::stat(from.c_str(), &from_st))
+#else
+  if (::os_stat(from.c_str(), &from_st))
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
     {
       ec.assign(errno, std::generic_category());
       return;
     }
+#ifndef _GLIBCXX_FILESYSTEM_IS_WINDOWS
   if (use_lstat
       ? ::lstat(to.c_str(), &to_st)
       : ::stat(to.c_str(), &to_st))
+#else
+  if (::os_stat(to.c_str(), &to_st))
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
     {
       if (!is_not_found_errno(errno))
 	{
@@ -696,8 +701,12 @@
   {
     bool created = false;
 #ifdef _GLIBCXX_HAVE_SYS_STAT_H
+#ifndef _GLIBCXX_FILESYSTEM_IS_WINDOWS
     ::mode_t mode = static_cast<std::underlying_type_t<fs::perms>>(perm);
-    if (::mkdir(p.c_str(), mode))
+    if (::os_mkdir(p.c_str(), mode))
+#else
+    if (::os_mkdir(p.c_str()))
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
       {
 	const int err = errno;
 	if (err != EEXIST || !is_directory(p))
@@ -752,7 +761,7 @@
 {
 #ifdef _GLIBCXX_HAVE_SYS_STAT_H
   stat_type st;
-  if (::stat(attributes.c_str(), &st))
+  if (::os_stat(attributes.c_str(), &st))
     {
       ec.assign(errno, std::generic_category());
       return false;
@@ -801,7 +810,7 @@
 fs::create_hard_link(const path& to, const path& new_hard_link,
 		     error_code& ec) noexcept
 {
-#ifdef _GLIBCXX_HAVE_UNISTD_H
+#if !defined(_GLIBCXX_FILESYSTEM_IS_WINDOWS) && defined(_GLIBCXX_HAVE_UNISTD_H)
   if (::link(to.c_str(), new_hard_link.c_str()))
     ec.assign(errno, std::generic_category());
   else
@@ -825,7 +834,7 @@
 fs::create_symlink(const path& to, const path& new_symlink,
 		   error_code& ec) noexcept
 {
-#ifdef _GLIBCXX_HAVE_UNISTD_H
+#if !defined(_GLIBCXX_FILESYSTEM_IS_WINDOWS) && defined(_GLIBCXX_HAVE_UNISTD_H)
   if (::symlink(to.c_str(), new_symlink.c_str()))
     ec.assign(errno, std::generic_category());
   else
@@ -851,8 +860,8 @@
 {
   path p;
 #ifdef _GLIBCXX_HAVE_UNISTD_H
-#ifdef __GLIBC__
-  if (char_ptr cwd = char_ptr{::getcwd(nullptr, 0)})
+#if defined(__GLIBC__) || defined(_GLIBCXX_FILESYSTEM_IS_WINDOWS)
+  if (char_ptr cwd = char_ptr{::os_getcwd(nullptr, 0)})
     {
       p.assign(cwd.get());
       ec.clear();
@@ -910,7 +919,7 @@
 fs::current_path(const path& p, error_code& ec) noexcept
 {
 #ifdef _GLIBCXX_HAVE_UNISTD_H
-  if (::chdir(p.c_str()))
+  if (::os_chdir(p.c_str()))
     ec.assign(errno, std::generic_category());
   else
     ec.clear();
@@ -937,7 +946,7 @@
   int err = 0;
   file_status s1, s2;
   stat_type st1, st2;
-  if (::stat(p1.c_str(), &st1) == 0)
+  if (::os_stat(p1.c_str(), &st1) == 0)
     s1 = make_file_status(st1);
   else if (is_not_found_errno(errno))
     s1.type(file_type::not_found);
@@ -944,7 +953,7 @@
   else
     err = errno;
 
-  if (::stat(p2.c_str(), &st2) == 0)
+  if (::os_stat(p2.c_str(), &st2) == 0)
     s2 = make_file_status(st2);
   else if (is_not_found_errno(errno))
     s2.type(file_type::not_found);
@@ -994,7 +1003,7 @@
     {
 #ifdef _GLIBCXX_HAVE_SYS_STAT_H
       stat_type st;
-      if (::stat(p.c_str(), &st))
+      if (::os_stat(p.c_str(), &st))
 	{
 	  ec.assign(errno, std::generic_category());
 	  return deflt;
@@ -1044,8 +1053,14 @@
 std::uintmax_t
 fs::hard_link_count(const path& p, error_code& ec) noexcept
 {
+#ifndef _GLIBCXX_FILESYSTEM_IS_WINDOWS
   return do_stat(p, ec, std::mem_fn(&stat::st_nlink),
 		 static_cast<uintmax_t>(-1));
+#else
+  ec = std::make_error_code(std::errc::not_supported);
+
+  return static_cast<uintmax_t>(-1);
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
 }
 
 bool
@@ -1120,11 +1135,11 @@
   else
     ec.clear();
 #elif _GLIBCXX_HAVE_UTIME_H
-  ::utimbuf times;
+  ::os_utimbuf_t times;
   times.modtime = s.count();
   times.actime = do_stat(p, ec, [](const auto& st) { return st.st_atime; },
 			 times.modtime);
-  if (::utime(p.c_str(), &times))
+  if (::os_utime(p.c_str(), &times))
     ec.assign(errno, std::generic_category());
   else
     ec.clear();
@@ -1177,7 +1192,7 @@
 #else
   if (nofollow && is_symlink(st))
     ec = std::make_error_code(std::errc::operation_not_supported);
-  else if (::chmod(p.c_str(), static_cast<mode_t>(prms)))
+  else if (::os_chmod(p.c_str(), static_cast<mode_t>(prms)))
     err = errno;
 #endif
 
@@ -1199,7 +1214,7 @@
 
 fs::path fs::read_symlink(const path& p, error_code& ec)
 {
-#ifdef _GLIBCXX_HAVE_SYS_STAT_H
+#if !defined(_GLIBCXX_FILESYSTEM_IS_WINDOWS) && defined(_GLIBCXX_HAVE_SYS_STAT_H)
   stat_type st;
   if (::lstat(p.c_str(), &st))
     {
@@ -1237,7 +1252,7 @@
 {
   if (exists(symlink_status(p, ec)))
     {
-      if (::remove(p.c_str()) == 0)
+      if (::os_remove(p.c_str()) == 0)
 	{
 	  ec.clear();
 	  return true;
@@ -1284,7 +1299,7 @@
 void
 fs::rename(const path& from, const path& to, error_code& ec) noexcept
 {
-  if (::rename(from.c_str(), to.c_str()))
+  if (::os_rename(from.c_str(), to.c_str()))
     ec.assign(errno, std::generic_category());
   else
     ec.clear();
@@ -1305,7 +1320,7 @@
 #ifdef _GLIBCXX_HAVE_UNISTD_H
   if (size > static_cast<uintmax_t>(std::numeric_limits<off_t>::max()))
     ec.assign(EINVAL, std::generic_category());
-  else if (::truncate(p.c_str(), size))
+  else if (::os_truncate(p.c_str(), size))
     ec.assign(errno, std::generic_category());
   else
     ec.clear();
@@ -1358,7 +1373,7 @@
 {
   file_status status;
   stat_type st;
-  if (::stat(p.c_str(), &st))
+  if (::os_stat(p.c_str(), &st))
     {
       int err = errno;
       ec.assign(err, std::generic_category());
@@ -1376,11 +1391,13 @@
     }
   return status;
 }
+#endif // _GLIBCXX_FILESYSTEM_IS_WINDOWS
 
 fs::file_status
 fs::symlink_status(const fs::path& p, std::error_code& ec) noexcept
 {
   file_status status;
+#if !defined(_GLIBCXX_FILESYSTEM_IS_WINDOWS) && defined(_GLIBCXX_HAVE_SYS_STAT_H)
   stat_type st;
   if (::lstat(p.c_str(), &st))
     {
@@ -1394,9 +1411,11 @@
       status = make_file_status(st);
       ec.clear();
     }
+#else
+  ec = std::make_error_code(std::errc::not_supported);
+#endif
   return status;
 }
-#endif
 
 fs::file_status
 fs::status(const fs::path& p)
Index: libstdc++-v3/src/filesystem/path.cc
===================================================================
--- libstdc++-v3/src/filesystem/path.cc	(revision 246136)
+++ libstdc++-v3/src/filesystem/path.cc	(working copy)
@@ -296,7 +296,7 @@
 std::pair<const path::string_type*, std::size_t>
 path::_M_find_extension() const
 {
-  const std::string* s = nullptr;
+  const path::string_type* s = nullptr;
 
   if (_M_type != _Type::_Multi)
     s = &_M_pathname;