Re: [Lzip-bug] S_ISVTX is undefined without _XOPEN_SOURCE

[Antonio Diaz Diaz]

Hello,

Charlie Lin wrote:
> The patch adds _XOPEN_SOURCE=500
> Explaination: on glibc, S_ISVTX is only visible if the aformentioned
> macro is defined.
>
> Compiler: gcc 7.2.1
> CFLAGS=-Wall -Wextra -Werror -Wpedantic -fno-builtin -std=c99

This is true, but I expect that any user requesting a particular version 
of the standard (in this case C99) would also specify the XOPEN level 
(as in -D_XOPEN_SOURCE=500). At least this is how I test clzip.

I would prefer to not define _XOPEN_SOURCE in the source to prevent 
interferences with other compiler options. For example, a conflict may 
happen[1] if I apply the patch and the user specifies 
'-D_POSIX_C_SOURCE=200809L'.

[1] 
http://pubs.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html
"Therefore, if _XOPEN_SOURCE is set equal to 600 and _POSIX_C_SOURCE is 
set equal to 200112L, the behavior is the same as if only _XOPEN_SOURCE 
is defined and set equal to 600. However, should _POSIX_C_SOURCE be set 
to a value greater than 200112L, the behavior is unspecified."


Best regards,
Antonio.