On Sat, Jul 18, 2009 at 1:58 PM, Ramsay Jones<ramsay@xxxxxxxxxxxxxxxxxxx> wrote:
>
> These sparse warnings are caused by broken new-lib headers,
> which sometimes result in NULL being defined as 0, and at
> other times defined as ((void *)0).
>
> In essence, the only header which works correctly (by defining
> NULL as ((void *)0)) is stddef.h. The stdio.h and time.h headers
> also work, almost by accident, by indirectly including stddef.h.
> The other standard headers which are required to define the NULL
> macro, namely locale.h, stdlib.h, string.h and wchar.h, all
> define the macro as the 0 token. (This is a slightly simplified
> description of the problem).
>
> In order to suppress these warnings, include the stddef.h header
> at the start of ptrlist.c.
>
> Signed-off-by: Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxx>
> ---
>
> Hi Chris,
>
> $ cat -n null-test.sh
> 1 #!/bin/bash
> 2
> 3 # The C99 standard says that the following headers define NULL:
> 4 # locale.h (7.11), stddef.h (7.17), stdio.h (7.19.1),
> 5 # stdlib.h (7.20), string.h (7.21.1), time.h (7.23.1),
> 6 # wchar.h (7.24.1).
> 7
> 8 for i in locale.h stddef.h stdio.h stdlib.h string.h time.h wchar.h
> 9 do
> 10 printf "%10s: " $i
> 11 printf "#include<%s>\nchar *xyz_ptr = NULL;\n" $i >t.c
> 12 cgcc -E t.c | grep xyz_ptr
> 13 done
> 14 rm t.c
> 15
> $ ./null-test.sh
That is what I get in FC11:
locale.h: char *xyz_ptr = ((void *)0);
stddef.h: char *xyz_ptr = ((void *)0);
stdio.h: char *xyz_ptr = ((void *)0);
stdlib.h: char *xyz_ptr = ((void *)0);
string.h: char *xyz_ptr = ((void *)0);
time.h: char *xyz_ptr = ((void *)0);
wchar.h: char *xyz_ptr = ((void *)0);
Which system has this problem?
Chris
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