diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 6ae141b8c2070a86dffc05205430e997cbc942d4..1920444e5cd9d2aac64f9eceab5f58fd24f6dcfb 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4956,6 +4956,7 @@ dnl _GLIBCXX_USE_FCHMOD
dnl _GLIBCXX_USE_FCHMODAT
dnl _GLIBCXX_USE_SENDFILE
dnl HAVE_LINK
+dnl HAVE_LSEEK
dnl HAVE_READLINK
dnl HAVE_SYMLINK
dnl
@@ -5091,25 +5092,6 @@ dnl
if test $glibcxx_cv_fchmodat = yes; then
AC_DEFINE(_GLIBCXX_USE_FCHMODAT, 1, [Define if fchmodat is available in <sys/stat.h>.])
fi
-dnl
- AC_CACHE_CHECK([for sendfile that can copy files],
- glibcxx_cv_sendfile, [dnl
- case "${target_os}" in
- gnu* | linux* | solaris* | uclinux*)
- GCC_TRY_COMPILE_OR_LINK(
- [#include <sys/sendfile.h>],
- [sendfile(1, 2, (off_t*)0, sizeof 1);],
- [glibcxx_cv_sendfile=yes],
- [glibcxx_cv_sendfile=no])
- ;;
- *)
- glibcxx_cv_sendfile=no
- ;;
- esac
- ])
- if test $glibcxx_cv_sendfile = yes; then
- AC_DEFINE(_GLIBCXX_USE_SENDFILE, 1, [Define if sendfile is available in <sys/sendfile.h>.])
- fi
dnl
AC_CACHE_CHECK([for link],
glibcxx_cv_link, [dnl
@@ -5122,6 +5104,18 @@ dnl
if test $glibcxx_cv_link = yes; then
AC_DEFINE(HAVE_LINK, 1, [Define if link is available in <unistd.h>.])
fi
+dnl
+ AC_CACHE_CHECK([for lseek],
+ glibcxx_cv_lseek, [dnl
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <unistd.h>],
+ [lseek(1, 0, SEEK_SET);],
+ [glibcxx_cv_lseek=yes],
+ [glibcxx_cv_lseek=no])
+ ])
+ if test $glibcxx_cv_lseek = yes; then
+ AC_DEFINE(HAVE_LSEEK, 1, [Define if lseek is available in <unistd.h>.])
+ fi
dnl
AC_CACHE_CHECK([for readlink],
glibcxx_cv_readlink, [dnl
@@ -5158,6 +5152,25 @@ dnl
if test $glibcxx_cv_truncate = yes; then
AC_DEFINE(HAVE_TRUNCATE, 1, [Define if truncate is available in <unistd.h>.])
fi
+dnl
+ AC_CACHE_CHECK([for sendfile that can copy files],
+ glibcxx_cv_sendfile, [dnl
+ case "${target_os}" in
+ gnu* | linux* | solaris* | uclinux*)
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <sys/sendfile.h>],
+ [sendfile(1, 2, (off_t*)0, sizeof 1);],
+ [glibcxx_cv_sendfile=yes],
+ [glibcxx_cv_sendfile=no])
+ ;;
+ *)
+ glibcxx_cv_sendfile=no
+ ;;
+ esac
+ ])
+ if test $glibcxx_cv_sendfile = yes && test $glibcxx_cv_lseek = yes; then
+ AC_DEFINE(_GLIBCXX_USE_SENDFILE, 1, [Define if sendfile is available in <sys/sendfile.h>.])
+ fi
dnl
AC_CACHE_CHECK([for fdopendir],
glibcxx_cv_fdopendir, [dnl
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index 5a95853cbbe43228e88fa32a007ab65a08ac3fa3..99ce682670e919769eeb14c1664c23e6f8af93d6 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -254,6 +254,9 @@
/* Define to 1 if you have the `logl' function. */
#undef HAVE_LOGL
+/* Define if lseek is available in <unistd.h>. */
+#undef HAVE_LSEEK
+
/* Define to 1 if you have the <machine/endian.h> header file. */
#undef HAVE_MACHINE_ENDIAN_H
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 70d169cf64bcda2e9b261b3f36a053650a2d5f0f..50a7c30665b938476e3c12c9731f52aec617b79a 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -71005,29 +71005,27 @@ $as_echo "$glibcxx_cv_fchmodat" >&6; }
$as_echo "#define _GLIBCXX_USE_FCHMODAT 1" >>confdefs.h
fi
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for sendfile that can copy files" >&5
-$as_echo_n "checking for sendfile that can copy files... " >&6; }
-if ${glibcxx_cv_sendfile+:} false; then :
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for link" >&5
+$as_echo_n "checking for link... " >&6; }
+if ${glibcxx_cv_link+:} false; then :
$as_echo_n "(cached) " >&6
else
- case "${target_os}" in
- gnu* | linux* | solaris* | uclinux*)
- if test x$gcc_no_link = xyes; then
+ if test x$gcc_no_link = xyes; then
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
-#include <sys/sendfile.h>
+#include <unistd.h>
int
main ()
{
-sendfile(1, 2, (off_t*)0, sizeof 1);
+link("", "");
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
- glibcxx_cv_sendfile=yes
+ glibcxx_cv_link=yes
else
- glibcxx_cv_sendfile=no
+ glibcxx_cv_link=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
else
@@ -71036,40 +71034,35 @@ else
fi
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
-#include <sys/sendfile.h>
+#include <unistd.h>
int
main ()
{
-sendfile(1, 2, (off_t*)0, sizeof 1);
+link("", "");
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_link "$LINENO"; then :
- glibcxx_cv_sendfile=yes
+ glibcxx_cv_link=yes
else
- glibcxx_cv_sendfile=no
+ glibcxx_cv_link=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
fi
- ;;
- *)
- glibcxx_cv_sendfile=no
- ;;
- esac
fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_sendfile" >&5
-$as_echo "$glibcxx_cv_sendfile" >&6; }
- if test $glibcxx_cv_sendfile = yes; then
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_link" >&5
+$as_echo "$glibcxx_cv_link" >&6; }
+ if test $glibcxx_cv_link = yes; then
-$as_echo "#define _GLIBCXX_USE_SENDFILE 1" >>confdefs.h
+$as_echo "#define HAVE_LINK 1" >>confdefs.h
fi
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for link" >&5
-$as_echo_n "checking for link... " >&6; }
-if ${glibcxx_cv_link+:} false; then :
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for lseek" >&5
+$as_echo_n "checking for lseek... " >&6; }
+if ${glibcxx_cv_lseek+:} false; then :
$as_echo_n "(cached) " >&6
else
if test x$gcc_no_link = xyes; then
@@ -71079,15 +71072,15 @@ else
int
main ()
{
-link("", "");
+lseek(1, 0, SEEK_SET);
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
- glibcxx_cv_link=yes
+ glibcxx_cv_lseek=yes
else
- glibcxx_cv_link=no
+ glibcxx_cv_lseek=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
else
@@ -71100,26 +71093,26 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
int
main ()
{
-link("", "");
+lseek(1, 0, SEEK_SET);
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_link "$LINENO"; then :
- glibcxx_cv_link=yes
+ glibcxx_cv_lseek=yes
else
- glibcxx_cv_link=no
+ glibcxx_cv_lseek=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
fi
fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_link" >&5
-$as_echo "$glibcxx_cv_link" >&6; }
- if test $glibcxx_cv_link = yes; then
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_lseek" >&5
+$as_echo "$glibcxx_cv_lseek" >&6; }
+ if test $glibcxx_cv_lseek = yes; then
-$as_echo "#define HAVE_LINK 1" >>confdefs.h
+$as_echo "#define HAVE_LSEEK 1" >>confdefs.h
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for readlink" >&5
@@ -71286,6 +71279,68 @@ $as_echo "$glibcxx_cv_truncate" >&6; }
$as_echo "#define HAVE_TRUNCATE 1" >>confdefs.h
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for sendfile that can copy files" >&5
+$as_echo_n "checking for sendfile that can copy files... " >&6; }
+if ${glibcxx_cv_sendfile+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ case "${target_os}" in
+ gnu* | linux* | solaris* | uclinux*)
+ if test x$gcc_no_link = xyes; then
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <sys/sendfile.h>
+int
+main ()
+{
+sendfile(1, 2, (off_t*)0, sizeof 1);
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ glibcxx_cv_sendfile=yes
+else
+ glibcxx_cv_sendfile=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+ if test x$gcc_no_link = xyes; then
+ as_fn_error $? "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <sys/sendfile.h>
+int
+main ()
+{
+sendfile(1, 2, (off_t*)0, sizeof 1);
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_sendfile=yes
+else
+ glibcxx_cv_sendfile=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+fi
+ ;;
+ *)
+ glibcxx_cv_sendfile=no
+ ;;
+ esac
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_sendfile" >&5
+$as_echo "$glibcxx_cv_sendfile" >&6; }
+ if test $glibcxx_cv_sendfile = yes && test $glibcxx_cv_lseek = yes; then
+
+$as_echo "#define _GLIBCXX_USE_SENDFILE 1" >>confdefs.h
+
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for fdopendir" >&5
$as_echo_n "checking for fdopendir... " >&6; }
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index c95511b5c959d7fcd474a24bb0b598b13917b8b6..364443882089cea9d870a2ed8d8fb570dbeebfd7 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -51,6 +51,7 @@
# include <ext/stdio_filebuf.h>
# ifdef _GLIBCXX_USE_SENDFILE
# include <sys/sendfile.h> // sendfile
+# include <unistd.h> // lseek
# endif
#endif
@@ -358,6 +359,34 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
}
#ifdef NEED_DO_COPY_FILE
+#if defined _GLIBCXX_USE_SENDFILE && ! defined _GLIBCXX_FILESYSTEM_IS_WINDOWS
+ bool
+ copy_file_sendfile(int fd_in, int fd_out, size_t length) noexcept
+ {
+ // a zero-length file is either empty, or not copyable by this syscall
+ // return early to avoid the syscall cost
+ if (length == 0)
+ {
+ errno = EINVAL;
+ return false;
+ }
+ size_t bytes_left = length;
+ off_t offset = 0;
+ ssize_t bytes_copied;
+ do
+ {
+ bytes_copied = ::sendfile(fd_out, fd_in, &offset, bytes_left);
+ bytes_left -= bytes_copied;
+ }
+ while (bytes_left > 0 && bytes_copied > 0);
+ if (bytes_copied < 0)
+ {
+ ::lseek(fd_out, 0, SEEK_SET);
+ return false;
+ }
+ return true;
+ }
+#endif
bool
do_copy_file(const char_type* from, const char_type* to,
std::filesystem::copy_options_existing_file options,
@@ -498,16 +527,22 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
return false;
}
- size_t count = from_st->st_size;
+ bool has_copied = false;
+
#if defined _GLIBCXX_USE_SENDFILE && ! defined _GLIBCXX_FILESYSTEM_IS_WINDOWS
- off_t offset = 0;
- ssize_t n = ::sendfile(out.fd, in.fd, &offset, count);
- if (n < 0 && errno != ENOSYS && errno != EINVAL)
+ if (!has_copied)
+ has_copied = copy_file_sendfile(in.fd, out.fd, from_st->st_size);
+ if (!has_copied)
{
- ec.assign(errno, std::generic_category());
- return false;
+ if (errno != ENOSYS && errno != EINVAL)
+ {
+ ec.assign(errno, std::generic_category());
+ return false;
+ }
}
- if ((size_t)n == count)
+#endif
+
+ if (has_copied)
{
if (!out.close() || !in.close())
{
@@ -517,9 +552,6 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
ec.clear();
return true;
}
- else if (n > 0)
- count -= n;
-#endif // _GLIBCXX_USE_SENDFILE
using std::ios;
__gnu_cxx::stdio_filebuf<char> sbin(in.fd, ios::in|ios::binary);
@@ -530,29 +562,12 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
if (sbout.is_open())
out.fd = -1;
-#ifdef _GLIBCXX_USE_SENDFILE
- if (n != 0)
- {
- if (n < 0)
- n = 0;
-
- const auto p1 = sbin.pubseekoff(n, ios::beg, ios::in);
- const auto p2 = sbout.pubseekoff(n, ios::beg, ios::out);
-
- const std::streampos errpos(std::streamoff(-1));
- if (p1 == errpos || p2 == errpos)
- {
- ec = std::make_error_code(std::errc::io_error);
- return false;
- }
- }
-#endif
-
- if (count && !(std::ostream(&sbout) << &sbin))
+ if (from_st->st_size && !(std::ostream(&sbout) << &sbin))
{
ec = std::make_error_code(std::errc::io_error);
return false;
}
+
if (!sbout.close() || !sbin.close())
{
ec.assign(errno, std::generic_category());