svn commit: r254273 - in head: . include lib lib/libc/iconv lib/libiconv_compat lib/libkiconv share/mk sys/sys tools/build/mk

[Dimitry Andric]

On Aug 13, 2013, at 09:15, Peter Wemm <peter at FreeBSD.org> wrote:
> Author: peter
> Date: Tue Aug 13 07:15:01 2013
> New Revision: 254273
> URL: http://svnweb.freebsd.org/changeset/base/254273
> 
> Log:
>  The iconv in libc did two things - implement the standard APIs, the GNU
>  extensions and also tried to be link time compatible with ports libiconv.
>  This splits that functionality and enables the parts that shouldn't
>  interfere with the port by default.
> 
>  WITH_ICONV (now on by default) - adds iconv.h, iconv_open(3) etc.
>  WITH_LIBICONV_COMPAT (off by default) adds the libiconv_open etc API, linker
>  symbols and even a stub libiconv.so.3 that are good enough to be able
>  to 'pkg delete -f libiconv' on a running system and reasonably expect it
>  to work.
> 
>  I have tortured many machines over the last few days to try and reduce
>  the possibilities of foot-shooting as much as I can.  I've successfully
>  recompiled to enable and disable the libiconv_compat modes, ports that use
>  libiconv alongside system iconv etc.  If you don't enable the
>  WITH_LIBICONV_COMPAT switch, they don't share symbol space.
> 
>  This is an extension of behavior on other system.  iconv(3) is a standard
>  libc interface and libiconv port expects to be able to run alongside it on
>  systems that have it.

Unfortunately I expect this will break many ports, when the libiconv
port is installed.  A simple example is the following:

  #include <iconv.h>

  int main(void)
  {
    iconv_t ic = iconv_open("UTF-8", "ISO-8859-1");
    iconv_close(ic);
    return 0;
  }

If you compile this on a system after r254273 with -I/usr/local/include,
and the libiconv port installed, it will result in:

  $ cc -I/usr/local/include iconv-test.c -o iconv-test
  /tmp/iconv-test-I1ltw1.o: In function `main':
  iconv-test.c:(.text+0x21): undefined reference to `libiconv_open'
  iconv-test.c:(.text+0x2f): undefined reference to `libiconv_close'
  cc: error: linker command failed with exit code 1 (use -v to see invocation)

This is because libiconv's iconv.h does:

  #define iconv_open libiconv_open
  ...
  #define iconv_close libiconv_close

and so on for most of its functions.

-Dimitry