Index: llvm/include/llvm/Support/FileSystem.h
===================================================================
--- llvm/include/llvm/Support/FileSystem.h
+++ llvm/include/llvm/Support/FileSystem.h
@@ -464,6 +464,32 @@
return !equivalent(A, B, result) && result;
}
+/// @brief Is the file mounted on a local filesystem?
+///
+/// @param path Input path.
+/// @param result Set to true if \a path is on fixed media such as a hard disk,
+/// false if it is not.
+/// @returns errc::success if result has been successfully set, otherwise a
+/// platform specific error_code.
+std::error_code is_local(const Twine &path, bool &result);
+
+/// @brief Version of is_local accepting an open file descriptor.
+std::error_code is_local(int FD, bool &result);
+
+/// @brief Simpler version of is_local for clients that don't need to
+/// differentiate between an error and false.
+inline bool is_local(const Twine &Path) {
+ bool Result;
+ return !is_local(Path, Result) && Result;
+}
+
+/// @brief Simpler version of is_local accepting an open file descriptor for
+/// clients that don't need to differentiate between an error and false.
+inline bool is_local(int FD) {
+ bool Result;
+ return !is_local(FD, Result) && Result;
+}
+
/// @brief Does status represent a directory?
///
/// @param status A file_status previously returned from status.
Index: llvm/lib/Support/MemoryBuffer.cpp
===================================================================
--- llvm/lib/Support/MemoryBuffer.cpp
+++ llvm/lib/Support/MemoryBuffer.cpp
@@ -297,6 +297,12 @@
if (MapSize < 4 * 4096 || MapSize < (unsigned)PageSize)
return false;
+ // Don't use mmap on files which are not on locally mounted file systems, as
+ // this can lead to instability if the filesystem is unmounted or a network
+ // connection is interrupted.
+ if (!sys::fs::is_local(FD))
+ return false;
+
if (!RequiresNullTerminator)
return true;
Index: llvm/lib/Support/Unix/Path.inc
===================================================================
--- llvm/lib/Support/Unix/Path.inc
+++ llvm/lib/Support/Unix/Path.inc
@@ -65,12 +65,14 @@
#endif
#include <sys/types.h>
-#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__ANDROID__)
+#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && \
+ !defined(__ANDROID__)
#include <sys/statvfs.h>
#define STATVFS statvfs
+#define FSTATVFS fstatvfs
#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
#else
-#ifdef __OpenBSD__
+#if defined(__OpenBSD__) || defined(__FreeBSD__)
#include <sys/param.h>
#include <sys/mount.h>
#elif defined(__ANDROID__)
@@ -79,9 +81,15 @@
#include <sys/mount.h>
#endif
#define STATVFS statfs
+#define FSTATVFS fstatfs
#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
#endif
+#if defined(__NetBSD__)
+#define STATVFS_F_FLAG(vfs) (vfs).f_flag
+#else
+#define STATVFS_F_FLAG(vfs) (vfs).f_flags
+#endif
using namespace llvm;
@@ -335,6 +343,39 @@
return std::error_code();
}
+static bool is_local_impl(struct STATVFS &Vfs) {
+#if defined(__linux__)
+ constexpr uint32_t CIFS_MAGIC_NUMBER = 0xFF534D42;
+ switch ((uint32_t)Vfs.f_type) {
+ case NFS_SUPER_MAGIC:
+ case SMB_SUPER_MAGIC:
+ case CIFS_MAGIC_NUMBER:
+ return false;
+ default:
+ return true;
+ }
+#else
+ return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
+#endif
+}
+
+std::error_code is_local(const Twine &Path, bool &Result) {
+ struct STATVFS Vfs;
+ if (::STATVFS(Path.str().c_str(), &Vfs))
+ return std::error_code(errno, std::generic_category());
+
+ Result = is_local_impl(Vfs);
+ return std::error_code();
+}
+
+std::error_code is_local(int FD, bool &Result) {
+ struct STATVFS Vfs;
+ if (::FSTATVFS(FD, &Vfs))
+ return std::error_code(errno, std::generic_category());
+
+ return is_local_impl(Vfs, Result);
+}
+
std::error_code rename(const Twine &from, const Twine &to) {
// Get arguments.
SmallString<128> from_storage;
@@ -491,6 +532,23 @@
int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
+#if defined(__APPLE__)
+//----------------------------------------------------------------------
+// Newer versions of MacOSX have a flag that will allow us to read from
+// binaries whose code signature is invalid without crashing by using
+// the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media
+// is mapped we can avoid crashing and return zeroes to any pages we try
+// to read if the media becomes unavailable by using the
+// MAP_RESILIENT_MEDIA flag.
+//----------------------------------------------------------------------
+#if defined(MAP_RESILIENT_CODESIGN)
+ flags |= MAP_RESILIENT_CODESIGN;
+#endif
+#if defined(MAP_RESILIENT_MEDIA)
+ flags |= MAP_RESILIENT_MEDIA;
+#endif
+#endif // #if defined (__APPLE__)
+
Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
if (Mapping == MAP_FAILED)
return std::error_code(errno, std::generic_category());
Index: llvm/lib/Support/Windows/Path.inc
===================================================================
--- llvm/lib/Support/Windows/Path.inc
+++ llvm/lib/Support/Windows/Path.inc
@@ -277,6 +277,80 @@
return std::error_code();
}
+static std::error_code is_local_internal(SmallVectorImpl<wchar_t> &Path,
+ bool &Result) {
+ SmallVector<wchar_t, 128> VolumePath;
+ size_t Len = 128;
+ while (true) {
+ VolumePath.resize(Len);
+ BOOL Success =
+ ::GetVolumePathNameW(Path.data(), VolumePath.data(), VolumePath.size());
+
+ if (Success)
+ break;
+
+ DWORD Err = ::GetLastError();
+ if (Err != ERROR_INSUFFICIENT_BUFFER)
+ return mapWindowsError(Err);
+
+ Len *= 2;
+ }
+ // If the output buffer has exactly enough space for the path name, but not
+ // the null terminator, it will leave the output unterminated. Push a null
+ // terminator onto the end to ensure that this never happens.
+ VolumePath.push_back(L'\0');
+ VolumePath.set_size(wcslen(VolumePath.data()));
+ const wchar_t *P = VolumePath.data();
+
+ UINT Type = ::GetDriveTypeW(P);
+ switch (Type) {
+ case DRIVE_FIXED:
+ Result = true;
+ return std::error_code();
+ case DRIVE_REMOTE:
+ case DRIVE_CDROM:
+ case DRIVE_RAMDISK:
+ case DRIVE_REMOVABLE:
+ Result = false;
+ return std::error_code();
+ default:
+ return make_error_code(errc::no_such_file_or_directory);
+ }
+ llvm_unreachable("Unreachable!");
+}
+
+std::error_code is_local(const Twine &path, bool &result) {
+ if (!llvm::sys::fs::exists(path) || !llvm::sys::path::has_root_path(path))
+ return make_error_code(errc::no_such_file_or_directory);
+
+ SmallString<128> Storage;
+ StringRef P = path.toStringRef(Storage);
+
+ // Convert to utf-16.
+ SmallVector<wchar_t, 128> WidePath;
+ if (std::error_code ec = widenPath(P, WidePath))
+ return ec;
+ return is_local_internal(WidePath, result);
+}
+
+std::error_code is_local(int FD, bool &Result) {
+ SmallVector<wchar_t, 128> FinalPath;
+ HANDLE Handle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
+
+ size_t Len = 128;
+ do {
+ FinalPath.reserve(Len);
+ Len = ::GetFinalPathNameByHandleW(Handle, FinalPath.data(),
+ FinalPath.capacity() - 1, VOLUME_NAME_NT);
+ if (Len == 0)
+ return mapWindowsError(::GetLastError());
+ } while (Len > FinalPath.capacity());
+
+ FinalPath.set_size(Len);
+
+ return is_local_internal(FinalPath, Result);
+}
+
std::error_code rename(const Twine &from, const Twine &to) {
// Convert to utf-16.
SmallVector<wchar_t, 128> wide_from;
Index: llvm/unittests/Support/Path.cpp
===================================================================
--- llvm/unittests/Support/Path.cpp
+++ llvm/unittests/Support/Path.cpp
@@ -1136,6 +1136,28 @@
::close(FileDescriptor);
}
+TEST_F(FileSystemTest, is_local) {
+ SmallString<128> CurrentPath;
+ ASSERT_NO_ERROR(fs::current_path(CurrentPath));
+
+ bool Result;
+ ASSERT_NO_ERROR(fs::is_local(CurrentPath, Result));
+ EXPECT_TRUE(Result);
+ EXPECT_TRUE(fs::is_local(CurrentPath));
+
+ int FD;
+ SmallString<64> TempPath;
+ ASSERT_NO_ERROR(fs::createTemporaryFile("prefix", "temp", FD, TempPath));
+ FileRemover Cleanup(TempPath);
+
+ // Make sure it exists.
+ ASSERT_TRUE(sys::fs::exists(Twine(TempPath)));
+
+ ASSERT_NO_ERROR(fs::is_local(FD, Result));
+ EXPECT_TRUE(Result);
+ EXPECT_TRUE(fs::is_local(FD));
+}
+
TEST_F(FileSystemTest, set_current_path) {
SmallString<128> path;