Corinna Vinschen wrote:
On Feb 23 19:14, Christian Franke wrote:
Experiments with damaged USB flash drives and ddrescue revealed that the
current mapping of these Win32 errors to the fallback EACCES could be
improved.
BTW: I wonder why EACCES was selected as the fallback. Source code control
forensics suggest that this was decided in the last millennium. A related
comment from CGF added August 2000 persists until today :-)
/* FIXME: what's so special about EACCESS? */
This goes back until 1997 in pre-CVS times. There's a ChangeLog entry
Wed Oct 29 22:43:57 1997 Geoffrey Noer <n...@cygnus.com>
[...]
* syscalls.cc (seterrno): on failure, set EACCES instead of EPERM
which is better for the unknown error case
So the default was EPERM at first and has been changed to EACCES
because it "is better for the unknown error case".
I'm open to ideas for an improved error mapping.
I have no better suggestion for a default errno. Adding a cygwin
specific one (like ENMFILE, ENOSHARE and ECASECLASH added 2000-2001) is
possibly not desired.
Some thoughts about minor improvements of the errmap.h file:
- Add error number to each /* ERROR_... */ comment, e.g. /* 2:
ERROR_FILE_NOT_FOUND */.
- Update /* NUMBER */ comments using current MinGW-w64's winerror.h
(~850 changes).
- Max errno is 143, so data type size could be reduced from int to
uint8_t aka unsigned char. Could even add a compile time check by using
C++11's braced initializers which do not allow narrowing conversions.
- Remove trailing entries which only map to 0.
- Append a static_assert which checks whether array size matches the
last mapped error number.
I could provide separate patches if desired.
Thanks,
Christian
