Re: Missing -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 in pkg-config files in Clang + LLVM environment?

[Sam James]

> On 9 Sep 2022, at 01:02, Sam James <sam@gentoo.org> wrote:
> [snip]
> 
>>> This is on a musl + Clang system (details below for how
>>> to reproduce).
>> 
>> none of the systems that I develop on have musl.
>> (you're free to submit a patch, if you use musl).
>> 
> 
> Thanks, I'll take a look.

So, if I just do e.g.
```
--- a/Ada95/aclocal.m4
+++ b/Ada95/aclocal.m4
@@ -5056,6 +5056,9 @@ case "$host_os" in
        cf_xopen_source="-D_SGI_SOURCE"
        cf_XOPEN_SOURCE=
        ;;
+(linux*musl*)
+       CF_TRY_XOPEN_SOURCE
+       ;;
 (linux*|uclinux*|gnu*|mint*|k*bsd*-gnu|cygwin)
        CF_GNU_SOURCE($cf_XOPEN_SOURCE)
        ;;
```

It's insufficient because it thinks we don't need to set it.

Apparently this is because when building a test program
with
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
This ends up enabling XOPEN_SOURCE (some header
is defining it, I guess).

Is there a reason those headers are used for the tiny test
programs?

If I drop them from the include like so, all is well,
and configure adds XOPEN_SOURCE appropriately:

```
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -8377,9 +8377,6 @@ dnl can define it successfully.
 AC_DEFUN([CF_TRY_XOPEN_SOURCE],[
 AC_CACHE_CHECK(if we should define _XOPEN_SOURCE,cf_cv_xopen_source,[
        AC_TRY_COMPILE([
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
 ],[
 #ifndef _XOPEN_SOURCE
 make an error
@@ -8388,9 +8385,6 @@ make an error
        [cf_save="$CPPFLAGS"
         CF_APPEND_TEXT(CPPFLAGS,-D_XOPEN_SOURCE=$cf_XOPEN_SOURCE)
         AC_TRY_COMPILE([
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
 ],[
 #ifdef _XOPEN_SOURCE
 make an error
@@ -9915,6 +9909,9 @@ case "$host_os" in
        cf_xopen_source="-D_SGI_SOURCE"
        cf_XOPEN_SOURCE=
        ;;
+(linux*musl*)
+       CF_TRY_XOPEN_SOURCE
+       ;;
 (linux*|uclinux*|gnu*|mint*|k*bsd*-gnu|cygwin)
        CF_GNU_SOURCE($cf_XOPEN_SOURCE)
        ;;
```


> 
> Best,
> sam

signature.asc
Description: Message signed with OpenPGP