[hurd] Fix unconditional use of PATH_MAX
Patch by Samuel Thibault
The GNU/Hurd system does not define an arbitrary PATH_MAX limitation, the POSIX 2001 realpath
extension can be used instead, and the size of symlinks can be determined.
Reviewed as https://reviews.llvm.org/D54677
llvm-svn: 351414
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 0e997efd53e839c6f34d470ecf89bd1c734ea94b
diff --git a/src/filesystem/operations.cpp b/src/filesystem/operations.cpp
index b410618..54a234e 100644
--- a/src/filesystem/operations.cpp
+++ b/src/filesystem/operations.cpp
@@ -543,11 +543,19 @@
ErrorHandler<path> err("canonical", ec, &orig_p, &cwd);
path p = __do_absolute(orig_p, &cwd, ec);
+#if _POSIX_VERSION >= 200112
+ std::unique_ptr<char, decltype(&::free)>
+ hold(::realpath(p.c_str(), nullptr), &::free);
+ if (hold.get() == nullptr)
+ return err.report(capture_errno());
+ return {hold.get()};
+#else
char buff[PATH_MAX + 1];
char* ret;
if ((ret = ::realpath(p.c_str(), buff)) == nullptr)
return err.report(capture_errno());
return {ret};
+#endif
}
void __copy(const path& from, const path& to, copy_options options,
@@ -1089,16 +1097,27 @@
path __read_symlink(const path& p, error_code* ec) {
ErrorHandler<path> err("read_symlink", ec, &p);
- char buff[PATH_MAX + 1];
- error_code m_ec;
- ::ssize_t ret;
- if ((ret = ::readlink(p.c_str(), buff, PATH_MAX)) == -1) {
+#ifdef PATH_MAX
+ struct NullDeleter { void operator()(void*) const {} };
+ const size_t size = PATH_MAX + 1;
+ char stack_buff[size];
+ auto buff = std::unique_ptr<char[], NullDeleter>(stack_buff);
+#else
+ StatT sb;
+ if (::lstat(p.c_str(), &sb) == -1) {
return err.report(capture_errno());
}
- _LIBCPP_ASSERT(ret <= PATH_MAX, "TODO");
+ const size_t size = sb.st_size + 1;
+ auto buff = unique_ptr<char[]>(new char[size]);
+#endif
+ ::ssize_t ret;
+ if ((ret = ::readlink(p.c_str(), buff.get(), size)) == -1)
+ return err.report(capture_errno());
_LIBCPP_ASSERT(ret > 0, "TODO");
+ if (static_cast<size_t>(ret) >= size)
+ return err.report(errc::value_too_large);
buff[ret] = 0;
- return {buff};
+ return {buff.get()};
}
bool __remove(const path& p, error_code* ec) {