[Bug bootstrap/49247] New: libiberty configure assumes newlib does not supply psignal

["janis at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49247

           Summary: libiberty configure assumes newlib does not supply
                    psignal
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: janis@gcc.gnu.org


A build of GCC mainline for arm-none-eabi using mainline newlib fails
with:

/scratch/janisjo/arm-eabi-fsf/src/gcc-mainline/libiberty/strsignal.c:554:1:
error: conflicting types for 'psignal'
/scratch/janisjo/arm-eabi-fsf/install/arm-none-eabi/include/signal.h:27:6:
note: previous declaration of 'psignal' was here

where the installed version comes from newlib.  The libiberty version has
an argument with "char *" and the newlib version uses "const char *" for
that argument.

The newlib version of psignal was added on 2011-05-04.

The libiberty version of psignal is not compiled if HAVE_PSIGNAL is
defined, but when building against newlib it is never defined.

libiberty/configure.ac says:

  # If we are being configured for newlib, we know which functions
  # newlib provide and which ones we will be expected to provide.

and

    # Of the functions in $checkfuncs, newlib only has strerror.

This is no longer true, as the latest newlib now has psignal as well.
It could also be the case that later versions of newlib will have other
funtions in $checkfuncs.