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Re: [PATCH 3/3] posix: New Linux posix_spawn{p} implementation
- From: Paul Eggert <eggert at cs dot ucla dot edu>
- To: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, libc-alpha at sourceware dot org
- Date: Sat, 27 Feb 2016 19:24:18 -0800
- Subject: Re: [PATCH 3/3] posix: New Linux posix_spawn{p} implementation
- Authentication-results: sourceware.org; auth=none
- References: <1456495001-5298-1-git-send-email-adhemerval dot zanella at linaro dot org> <1456495001-5298-4-git-send-email-adhemerval dot zanella at linaro dot org> <56D0B319 dot 3060005 at cs dot ucla dot edu> <56D0D129 dot 2070201 at linaro dot org>
Adhemerval Zanella wrote:
I see using const on complex expression might help compiler
get logic errors (where the variable is set to a different value)
In that case, you should also put "register" in your local declarations too,
right? Something like this:
register const int prot = PROT_READ | PROT_WRITE;
That way, you are also guarded against errors where later code mistakenly
attempts to take the address of 'prot'.
You may think I'm joking, but I have worked with programmers who believe in this
sort of thing, and I have experience with (non-GNU) code using this style. The
problem with this approach is that the attributes get in the way of reading the
code. Attributes like 'const' can make sense for globals, but for local
variables the hassle of maintaining them typically outweighs the meager benefits
of having them. That's certainly the case for this example, anyway.