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Guard uses of lutimes, for portability

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This commit is contained in:
Brian McKenna 2022-09-15 05:56:57 +00:00 • committed by John Ericson
parent 05580a373f
commit 5be44d235a
4 changed files with 90 additions and 50 deletions
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78
src/libutil/file-system.cc
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@ -557,29 +557,69 @@ void replaceSymlink(const Path & target, const Path & link)
}
}
#ifndef _WIN32
static void setWriteTime(const fs::path & p, const struct stat & st)
void setWriteTime(
const std::filesystem::path & path,
time_t accessedTime,
time_t modificationTime,
std::optional<bool> optIsSymlink)
{
struct timeval times[2];
times[0] = {
.tv_sec = st.st_atime,
.tv_usec = 0,
#ifndef _WIN32
struct timeval times[2] = {
{
.tv_sec = accessedTime,
.tv_usec = 0,
},
{
.tv_sec = modificationTime,
.tv_usec = 0,
},
};
times[1] = {
.tv_sec = st.st_mtime,
.tv_usec = 0,
};
if (lutimes(p.c_str(), times) != 0)
throw SysError("changing modification time of '%s'", p);
}
#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);
#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);
}
};
#if HAVE_LUTIMES
if (lutimes(path.c_str(), times) == -1) {
if (errno == ENOSYS)
nonSymlink();
else
throw SysError("changing modification time of '%s'", path);
}
#else
nonSymlink();
#endif
}
void setWriteTime(const fs::path & path, const struct stat & st)
{
setWriteTime(path, st.st_atime, st.st_mtime, S_ISLNK(st.st_mode));
}
void copyFile(const fs::path & from, const fs::path & to, bool andDelete)
{
#ifndef _WIN32
// TODO: Rewrite the `is_*` to use `symlink_status()`
auto statOfFrom = lstat(from.c_str());
#endif
auto fromStatus = fs::symlink_status(from);
// Mark the directory as writable so that we can delete its children
@ -599,9 +639,7 @@ void copyFile(const fs::path & from, const fs::path & to, bool andDelete)
throw Error("file '%s' has an unsupported type", from);
}
#ifndef _WIN32
setWriteTime(to, statOfFrom);
#endif
setWriteTime(to, lstat(from.string().c_str()));
if (andDelete) {
if (!fs::is_symlink(fromStatus))
fs::permissions(from, fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow);