Use posix_fallocate instead of ftruncate.
This makes sure that space is actually available. With this change
running lld on a full file system causes it to exit with
failed to open foo: No space left on device
instead of crashing with a sigbus.
llvm-svn: 276017
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 84aafcb..ea439c6 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -329,8 +329,17 @@
}
std::error_code resize_file(int FD, uint64_t Size) {
+#if defined(HAVE_POSIX_FALLOCATE)
+ // If we have posix_fallocate use it. Unlike ftruncate it always allocates
+ // space, so we get an error if the disk is full.
+ if (int Err = ::posix_fallocate(FD, 0, Size))
+ return std::error_code(Err, std::generic_category());
+#else
+ // Use ftruncate as a fallback. It may or may not allocate space. At least on
+ // OS X with HFS+ it does.
if (::ftruncate(FD, Size) == -1)
return std::error_code(errno, std::generic_category());
+#endif
return std::error_code();
}