FreeBSD system iconv- errors during linking

[ghost]

Thanks for reporting your bug here! The following template will help with
giving as much information as possible so that it's easier to diagnose and
fix.

Upfront Information

Please provide the following information by running the command and providing
the output.

• Fvwm3 version (run: fvwm3 --version)

Does not apply as build fails.

fvwm source updated as of ...

commit ebe9655 (HEAD -> refs/heads/master, refs/remotes/origin/master, refs/remotes/origin/HEAD)
Author: Thomas Adam [email protected]
Date: Mar.2021.0316-2305 +0000

• Linux distribution or BSD name/version

  FreeBSD 12-STABLE (stable/12-n232872-af0cea80104)

• Platform (run: uname -sp)

  FreeBSD amd64

Expected Behaviour

Build would actually succeed with system iconv on FreeBSD 12.

Actual Behaviour

configure warns that it finds both system iconv and externally in libiconv ...

...
configure: WARNING: *** Both system iconv and libiconv found: use libiconv
configure: WARNING: *** Use --with-iconv-library=no to use the system iconv
...

A build succeeds with externally installed libiconv. But fails when trying to build
as suggested above during link time due to obviously missing symbols in system
iconv(3) ...

...
CCLD fvwm3
ld: error: undefined symbol: libiconv_open

referenced by Ficonv.c:236
Ficonv.o:(convert_charsets) in archive ../libs/libfvwm3.a
...
ld: error: undefined symbol: libiconv
referenced by Ficonv.c:278
Ficonv.o:(convert_charsets) in archive ../libs/libfvwm3.a
...
ld: error: undefined symbol: libiconv_close
referenced by Ficonv.c:340
Ficonv.o:(convert_charsets) in archive ../libs/libfvwm3.a
...
cc: error: linker command failed with exit code 1 (use -v to see invocation)
gmake[2]: *** [Makefile:572: fvwm3] Error 1
...

... symbols actually available (from manual page of iconv(3)) are ...

LIBRARY
Standard C Library (libc, -lc)

SYNOPSIS
#include <iconv.h>

    iconv_t
    iconv_open(const char *dstname, const char *srcname);

    int
    iconv_open_into(const char *dstname, const char *srcname,
        iconv_allocation_t *ptr);

    int
    iconv_close(iconv_t cd);

    size_t
    iconv(iconv_t cd, char ** restrict src, size_t * restrict srcleft,
        char ** restrict dst, size_t * restrict dstleft);

    size_t
    __iconv(iconv_t cd, char ** restrict src, size_t * restrict srcleft,
        char ** restrict dst, size_t * restrict dstleft, uint32_t flags,
        size_t * invalids);

...

Either adjust linking for FreeBSD iconv.

Or, insist only on external libiconv and do not suggest how to use system iconv on FreeBSD 12.

Steps to Reproduce

How can the problem be reproduced? For this, the following is helpful:

On recent FreeBSD 12, see build fail with system iconv as suggested by configure with "--with-iconv-library=no" option.

Extra Information

Attached is the configure+build log.
make-fvwm3.2021-0321.freebsd-iconv-fail.txt

[ThomasAdam]

Hi @Parv

Thanks. I cannot reproduce this problem at all. Is there any other steps I need to do to reproduce this?

[ghost]

(Where are my manners?)
Hi @ThomasAdam,

I have added a cut down configure+make script which reliably fails. I am sorry for not providing this initially.

make-fvwm3-freebsd-iconv.sh.txt

[ThomasAdam]

Thanks, @Parv

I see what's happening here. I'm going to switch fvwm3 to use gettext which will also sort out the iconv handling, as the AM_ICONV macro in configure.ac can be used (thus removing the same broken logic we currently use).

It'll take me a little bit of time, but for now you can at least build fvwm3 using libiconv. After this change, you'll be able to use both system and libiconv, and I'm keen to keep supporting both as well.

[ghost]

Thank you @ThomasAdam for looking into this. I will keep any eye on the issue to report back on successful build with system iconv.