12:01 p.m.
The more I look at this patch, the less I like it. I would summarise
why I think it's wrong here, but it's better if you look at the
message I posted on the gnulib mailing list here first:
http://lists.gnu.org/archive/html/bug-gnulib/2009-11/msg00434.html
Directly accessing errno on Windows is wrong: you won't see the true
reasons for an error by doing that. However depending on what the
call is and whether it was replaced by gnulib, the alternatives are a
lot more complicated.
This patch series attempts to Do The Right Thing with gnulib code as
it stands at the moment (assuming my understanding of gnulib error
handling is correct -- see above link).
I feel however that it's probably better to change gnulib error
handling to be more rational.
There's also an additional complication I discovered: MinGW error
values are often wrong. So that's a MinGW bug to take to the nice
upstream folks on the MinGW project.
Rich.
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12:03 p.m.
New subject: [PATCH 1/9] daemon error handling: Formalize access to errno.
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12:03 p.m.
New subject: [PATCH 2/9] daemon error handling: Remove direct access to errno.
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12:03 p.m.
New subject: [PATCH 3/9] daemon error handling: readdir code
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12:03 p.m.
New subject: [PATCH 4/9] daemon error handling: fix is_dir and is_file calls for Windows.
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12:04 p.m.
New subject: [PATCH 5/9] daemon error handling: fix case_sensitive_path for Windows.
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12:04 p.m.
New subject: [PATCH 6/9] daemon error handling: clear errors before all functions
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12:05 p.m.
New subject: [PATCH 7/9] daemon error handling: recursive_mkdir shouldn't need to set errno.
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New subject: [PATCH 8/9] daemon error handling: Change CHROOT_* macros handling of errno.
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12:05 p.m.
New subject: [PATCH 9/9] daemon error handling: gnulib calls need separate error handling.
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12:14 p.m.
On Fri, Nov 27, 2009 at 06:01:56PM +0000, Richard W.M. Jones wrote:
The more I look at this patch, the less I like it.
But I think some patches in this set do make sense to apply anyway:
[PATCH 1/9] daemon error handling: Formalize access to errno.
- I think the idea of formalizing access to errno, and in particular
not having code that saves and restores errno, is a good one.
[PATCH 5/9] daemon error handling: fix case_sensitive_path for Windows.
- This is really a separate issue and I think we should just apply
this one.
[PATCH 6/9] daemon error handling: clear errors before all functions
- Clearing errno before invoking stub functions seems like a
reasonable change to me. It can avoid incorrect error messages in
cases where error handling paths that aren't tested very much are
wrong, for virtually no cost.
[PATCH 7/9] daemon error handling: recursive_mkdir shouldn't need to
set errno.
- This one is basically a cleanup, it avoids setting errno in order to
communicate an error to the local caller, and I think we should
apply it.
[PATCH 8/9] daemon error handling: Change CHROOT_* macros handling of
errno.
- Chroot handling in general needs fixing for Win32, but I didn't like
the way the macros save and restore errno, and so I think this
change makes sense on its own.
Rich.
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Richard W.M. Jones