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author | 2020-08-26 22:10:35 +0300 | |
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committer | 2020-12-15 18:23:10 -0500 | |
commit | f684355e0292b8e24a0870ecfda126fb15c9eb93 (patch) | |
tree | bf4e61fda7aff9dcdd58c06072c9dc3747702cb7 | |
parent | Don't reject calls to MinGW's unusual _setjmp declaration. (diff) | |
download | llvm-project-f684355e0292b8e24a0870ecfda126fb15c9eb93.tar.gz llvm-project-f684355e0292b8e24a0870ecfda126fb15c9eb93.tar.bz2 llvm-project-f684355e0292b8e24a0870ecfda126fb15c9eb93.zip |
[Support][Windows] Fix incorrect GetFinalPathNameByHandleW() return value check in realPathFromHandle()
`GetFinalPathNameByHandleW(,,N,)` returns:
- `< N` on success (this value does not include the size of the terminating null character)
- `>= N` if buffer is too small (this value includes the size of the terminating null character)
So, when `N == Buffer.capacity() - 1`, we need to resize buffer if return value is > `Buffer.capacity() - 2`.
Also, we can set `N` to `Buffer.capacity()`.
Thus, without this patch `realPathFromHandle()` returns unfilled buffer when length of the final path of the file is equal to `Buffer.capacity()` or `Buffer.capacity() - 1`.
Reviewed By: andrewng, amccarth
Differential Revision: https://reviews.llvm.org/D86564
(cherry picked from commit ceffd6993c350b57f43cec3b6371b159fc4a3149)
-rw-r--r-- | llvm/lib/Support/Windows/Path.inc | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc index e352beb77616..365ab01c0a16 100644 --- a/llvm/lib/Support/Windows/Path.inc +++ b/llvm/lib/Support/Windows/Path.inc @@ -19,7 +19,6 @@ #include "llvm/Support/ConvertUTF.h" #include "llvm/Support/WindowsError.h" #include <fcntl.h> -#include <io.h> #include <sys/stat.h> #include <sys/types.h> @@ -352,13 +351,13 @@ std::error_code is_local(const Twine &path, bool &result) { static std::error_code realPathFromHandle(HANDLE H, SmallVectorImpl<wchar_t> &Buffer) { DWORD CountChars = ::GetFinalPathNameByHandleW( - H, Buffer.begin(), Buffer.capacity() - 1, FILE_NAME_NORMALIZED); - if (CountChars > Buffer.capacity()) { + H, Buffer.begin(), Buffer.capacity(), FILE_NAME_NORMALIZED); + if (CountChars && CountChars >= Buffer.capacity()) { // The buffer wasn't big enough, try again. In this case the return value // *does* indicate the size of the null terminator. Buffer.reserve(CountChars); CountChars = ::GetFinalPathNameByHandleW( - H, Buffer.data(), Buffer.capacity() - 1, FILE_NAME_NORMALIZED); + H, Buffer.begin(), Buffer.capacity(), FILE_NAME_NORMALIZED); } if (CountChars == 0) return mapWindowsError(GetLastError()); |