diff --git a/configure.ac b/configure.ac index fc59904f358..746e953ddf9 100644 --- a/configure.ac +++ b/configure.ac @@ -89,9 +89,10 @@ AC_LANG_POP(C++) AC_CHECK_FUNCS([statvfs pipe2 close_range]) -# Check for lutimes, optionally used for changing the mtime of -# symlinks. -AC_CHECK_FUNCS([lutimes]) +# Check for lutimes and utimensat, optionally used for changing the +# mtime of symlinks. +AC_CHECK_DECLS([AT_SYMLINK_NOFOLLOW], [], [], [[#include ]]) +AC_CHECK_FUNCS([lutimes utimensat]) # Check whether the store optimiser can optimise symlinks. diff --git a/src/libutil/file-system.cc b/src/libutil/file-system.cc index 224b78b23d5..fd51d7d3cbd 100644 --- a/src/libutil/file-system.cc +++ b/src/libutil/file-system.cc @@ -630,7 +630,28 @@ void setWriteTime( time_t modificationTime, std::optional optIsSymlink) { -#ifndef _WIN32 +#ifdef _WIN32 + // FIXME use `fs::last_write_time`. + // + // Would be nice to use std::filesystem unconditionally, but + // doesn't support access time just modification time. + // + // System clock vs File clock issues also make that annoying. + warn("Changing file times is not yet implemented on Windows, path is '%s'", path); +#elif HAVE_UTIMENSAT && HAVE_DECL_AT_SYMLINK_NOFOLLOW + struct timespec times[2] = { + { + .tv_sec = accessedTime, + .tv_nsec = 0, + }, + { + .tv_sec = modificationTime, + .tv_nsec = 0, + }, + }; + if (utimensat(AT_FDCWD, path.c_str(), times, AT_SYMLINK_NOFOLLOW) == -1) + throw SysError("changing modification time of '%s' (using `utimensat`)", path); +#else struct timeval times[2] = { { .tv_sec = accessedTime, @@ -641,42 +662,21 @@ void setWriteTime( .tv_usec = 0, }, }; -#endif - - auto nonSymlink = [&]{ - bool isSymlink = optIsSymlink - ? *optIsSymlink - : fs::is_symlink(path); - - if (!isSymlink) { -#ifdef _WIN32 - // FIXME use `fs::last_write_time`. - // - // Would be nice to use std::filesystem unconditionally, but - // doesn't support access time just modification time. - // - // System clock vs File clock issues also make that annoying. - warn("Changing file times is not yet implemented on Windows, path is '%s'", path); +#if HAVE_LUTIMES + if (lutimes(path.c_str(), times) == -1) + throw SysError("changing modification time of '%s'", path); #else - if (utimes(path.c_str(), times) == -1) { - - throw SysError("changing modification time of '%s' (not a symlink)", path); - } -#endif - } else { - throw Error("Cannot modification time of symlink '%s'", path); - } - }; + bool isSymlink = optIsSymlink + ? *optIsSymlink + : fs::is_symlink(path); -#if HAVE_LUTIMES - if (lutimes(path.c_str(), times) == -1) { - if (errno == ENOSYS) - nonSymlink(); - else - throw SysError("changing modification time of '%s'", path); + if (!isSymlink) { + if (utimes(path.c_str(), times) == -1) + throw SysError("changing modification time of '%s' (not a symlink)", path); + } else { + throw Error("Cannot modification time of symlink '%s'", path); } -#else - nonSymlink(); +#endif #endif } diff --git a/src/libutil/meson.build b/src/libutil/meson.build index 57b741a50a4..08413783d04 100644 --- a/src/libutil/meson.build +++ b/src/libutil/meson.build @@ -42,6 +42,8 @@ check_funcs = [ # Optionally used to try to close more file descriptors (e.g. before # forking) on Unix. 'sysconf', + # Optionally used for changing the mtime of files and symlinks. + 'utimensat', ] foreach funcspec : check_funcs define_name = 'HAVE_' + funcspec.underscorify().to_upper() @@ -49,6 +51,8 @@ foreach funcspec : check_funcs configdata.set(define_name, define_value) endforeach +configdata.set('HAVE_DECL_AT_SYMLINK_NOFOLLOW', cxx.has_header_symbol('fcntl.h', 'AT_SYMLINK_NOFOLLOW').to_int()) + subdir('build-utils-meson/threads') # Check if -latomic is needed