Re: Will autoconf work with -Werror=implicit-int and -Werror=implicit-function-declaration ?

* Zack Weinberg:

> Paul Eggert made some changes back in May that attempt to address this:
> commits 028526149ee804617a302ccef22cc6adbda681b0 and
> 33c26d2700f927432c756ccf7a4fc89403d35b95.  Do you have a minimized
> test case for the problem (both the original problem and any remaining
> issues you're aware of are useful to me)?

The latest installment of this issue is here:

  configure.ac: Define _DEFAULT_SOURCE along with _XOPEN_SOURCE
  <https://github.com/samtools/htslib/pull/1711>

I wasn't aware of this change from
33c26d2700f927432c756ccf7a4fc89403d35b95 ("Fix port of AC_FUNC_MMAP"),
or maybe I just forgot about it:

+#ifndef getpagesize
+# ifdef _SC_PAGESIZE
+#  define getpagesize() sysconf (_SC_PAGESIZE)
+# elif defined _SC_PAGE_SIZE
+#  define getpagesize() sysconf (_SC_PAGE_SIZE)
+# elif HAVE_GETPAGESIZE
+int getpagesize ();
+# else

This should indeed isolate this test from the outcome of the getpagesize
check because it now prefers sysconf.

I can't test this with htslib unfortunately because I'm not able to
build autoconf from sources for some reason.

Thanks,
Florian