Re: Fw: [PATCH newlib 0/1] sys/signal.h needs sys/_intsup.h

[C Howland <cc1964t@gmail.com>]

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> *From:* Newlib <newlib-bounces+craig.howland=caci.com@sourceware.org> on
> behalf of Joel Sherrill <joel@rtems.org>
> *Sent:* Wednesday, August 25, 2021 3:12 PM
> *To:* newlib@sourceware.org <newlib@sourceware.org>
> *Subject:* [PATCH newlib 0/1] sys/signal.h needs sys/_intsup.h
>
>
>
> Hi
>
> The recent addition of the sig2str block of code for definitions and
> prototypes resulted in the following one line program not compiling
> for RTEMS targets:
>
> #include <sys/signal.h>
>
> Turned out that __STDINT_EXP used to conditionalize the definition
> of SIG2STR_MAX isn't defined unless <sys/_intsup.h> is included.
> I guess the test code got lucky.
>
> It's a simple patch that needed more background and investigation
> than code.
>
> Is it safe to assume that including each POSIX and Standard C Library file
> independently should compile? If so, I will file a ticket to at least at
> those to the RTEMS compile only tests like the ones we have that check
> a method can be used per the specific includes in the POSIX specification.
>
>      While I would think that #include on any "top level" include file
would have to compile on its own, sys/signal.h does not fall under that
umbrella.  That is, I don't think any valid use would call for
#include <sys/signal.h>
rather than
#include <signal.h>
So I think the real question is whether the latter works.
     By "top level" include I mean one that is intended to be directly
included by a user program, as opposed to indirectly included through
another include (as one would expect sys/signal.h to be nested to
<signal.h>).
     I'm not saying it is not a good idea that it can compile standalone,
but that I don't think it should be viewed as a requirement for every file
under include, especially most of them under sys.  There are some under sys
that are called to be directly included by user programs, specifically
sys/types.h, but the vast majority are not, intended to be nested from
other system includes.  So making test cases to specifically test for this
does not actually seem to be a good general idea for all include files, but
maybe only a subset.
     Aside from that general-approach thinking, something seems very
strange here.  sys/signal.h does include stdint.h and stdint.h does include
sys/_intsup.h.  So something about your test case failing seems like it has
to be wrong.  (I am not set up to compile with the current version, so I
can't easily check it.)
                 Craig

> Sorry this slipped through.
>
> --joel
>
> Joel Sherrill (1):
>   sys/signal.h: <sys/_intsup.h> is needed for __STDINT_EXP
>
>  newlib/libc/include/sys/signal.h | 4 ++++
>  1 file changed, 4 insertions(+)
>
> --
> 2.24.4
>
>
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