Re: safer way to use gnulib

[Ben Abbott]

On Mar 15, 2010, at 5:10 PM, John W. Eaton wrote:

> On 20-Feb-2010, Jaroslav Hajek wrote:
> 
> | On Sat, Feb 20, 2010 at 8:49 PM, John W. Eaton <address@hidden> wrote:
> | > On 20-Feb-2010, John W. Eaton wrote:
> | >
> | > | On 20-Feb-2010, Jaroslav Hajek wrote:
> | > |
> | > | | What do you think? It seems that in the current state of affairs
> | > | | gnulib actually makes Octave less portable than before.
> | > |
> | > | Please see the following thread on the gnulib mailing list:
> | > |
> | > |   http://lists.gnu.org/archive/html/bug-gnulib/2010-02/msg00113.html
> | > |
> | > | The last method proposed in that thread would allow us to use gnulib
> | > | without having to modify Octave, and it would avoid the problems we
> | > | have with the rpl_ definitions.
> | >
> | > Looking at the thread in the archive, I realize that it may be a bit
> | > confusing to know precisely which messages I'm talking about here.
> | > The "last method proposed" is here:
> | >
> | >  http://lists.gnu.org/archive/html/bug-gnulib/2010-02/msg00142.html
> | >
> | > and Bruno Haible's response is here:
> | >
> | >  http://lists.gnu.org/archive/html/bug-gnulib/2010-02/msg00143.html
> | >
> | > jwe
> | >
> | 
> | It looks good. I don't think why enclosing #include inside namespace
> | should not work. #include directives are handled by the preprocessor.
> | The only problem might be with other #defines used by the system
> | library, but we can hardly do anything about that.
> 
> Bruno Haible has checked in his c++defs module to the gnulib archive
> and I checked in the following change to make Octave use the new
> scheme of referencing gnulib replacement functions in C++ as
> gnulib::FCN.
> 
>  http://hg.savannah.gnu.org/hgweb/octave/rev/479cc8a0a846
> 
> These changes should avoid the problems with gnulib defining rpl_*
> functions.  If you had trouble with these definitions in the past,
> please try updating (including your gnulib sources), removing your
> local fixes for the problems, and rebuilding.
> 
> Bruno's changes did not go as far as putting the system headers inside
> a namespace, so we do have to prefix all replacement functions with
> the namespace tag.  But we also get some help if we are using GCC.
> Calls to functions that might be replaced generate warnings of the
> form
> 
>  lex.cc:3659: warning: call to 'fprintf' declared with attribute warning: The 
> symbol ::fprintf refers to the system function. Use gnulib::fprintf instead.
> 
> Since these warnings for lex.cc and oct-parse.cc occur in generated
> code that (I think) does not have problems with the redefinitions, I
> chose to avoid the warnings there by undefining GNULIB_NAMESPACE after
> config.h is included.
> 
> Please let me know if you see any further problems related to the
> gnulib symbol definitions.
> 
> jwe

I'm not sure this is related, but with my tip as ...

$ hg tip
changeset:   10412:d2ac9433cd09
tag:         tip
user:        John W. Eaton <address@hidden>
date:        Mon Mar 15 16:56:14 2010 -0400
summary:     append AM_CPPFLAGS to libcruft_la_CPPFLAGS

... compiling octave fails with the error below.

/bin/sh ../libtool  --tag=CXX   --mode=compile g++-4.2 -DHAVE_CONFIG_H -I. -I.. 
           -I/sw/lib/flex/include -I/sw/include -O0 -g -m32 
-I/sw/include/freetype2 -I/sw/include/qhull -I/usr/include -I../libgnu 
-I../libgnu -I../libcruft/misc -I/sw/lib/flex/include -I/sw/include -O0 -g -m32 
-I/sw/include/freetype2 -I/sw/include/qhull -I/usr/include -I/sw/include -O0 -g 
-m32 -D_THREAD_SAFE -D_REENTRANT  -DHAVE_CONFIG_H -mieee-fp -I/sw/include 
-I/sw/include/freetype2 -I/sw/include -I/usr/X11/include   -Wall -W -Wshadow 
-Wold-style-cast -Wformat -I/sw/include -O0 -g -m32 -D_THREAD_SAFE -D_REENTRANT 
-D_THREAD_SAFE -pthread -I/sw/include -O0 -g -m32 -D_THREAD_SAFE -D_REENTRANT 
-MT liboctave_la-ODES.lo -MD -MP -MF .deps/liboctave_la-ODES.Tpo -c -o 
liboctave_la-ODES.lo `test -f 'ODES.cc' || echo './'`ODES.cc
libtool: compile:  g++-4.2 -DHAVE_CONFIG_H -I. -I.. -I/sw/lib/flex/include 
-I/sw/include -O0 -g -m32 -I/sw/include/freetype2 -I/sw/include/qhull 
-I/usr/include -I../libgnu -I../libgnu -I../libcruft/misc 
-I/sw/lib/flex/include -I/sw/include -O0 -g -m32 -I/sw/include/freetype2 
-I/sw/include/qhull -I/usr/include -I/sw/include -O0 -g -m32 -D_THREAD_SAFE 
-D_REENTRANT -DHAVE_CONFIG_H -mieee-fp -I/sw/include -I/sw/include/freetype2 
-I/sw/include -I/usr/X11/include -Wall -W -Wshadow -Wold-style-cast -Wformat 
-I/sw/include -O0 -g -m32 -D_THREAD_SAFE -D_REENTRANT -D_THREAD_SAFE -pthread 
-I/sw/include -O0 -g -m32 -D_THREAD_SAFE -D_REENTRANT -MT liboctave_la-ODES.lo 
-MD -MP -MF .deps/liboctave_la-ODES.Tpo -c ODES.cc  -fno-common -DPIC -o 
.libs/liboctave_la-ODES.o
In file included from /usr/include/sys/time.h:197,
                 from ../libgnu/sys/time.h:40,
                 from ../libgnu/sys/select.h:51,
                 from /usr/include/unistd.h:519,
                 from ../libgnu/unistd.h:29,
                 from 
/usr/include/c++/4.2.1/i686-apple-darwin10/bits/os_defines.h:61,
                 from 
/usr/include/c++/4.2.1/i686-apple-darwin10/bits/c++config.h:41,
                 from /usr/include/c++/4.2.1/cstddef:50,
                 from Array.h:30,
                 from MArray.h:28,
                 from dMatrix.h:27,
                 from ODESFunc.h:26,
                 from ODES.h:26,
                 from ODES.cc:27:
../libgnu/stdlib.h:737: error: previous declaration of ‘int _gl_warn_on_use’ 
with ‘C++’ linkage
../libgnu/time.h:350: error: conflicts with new declaration with ‘C’ linkage

Ben