> From: "Yen-Ju Chen" <[EMAIL PROTECTED]>
> Date: Tue, 10 Sep 2002 17:55:15 -0400
>
>
> Which version of GCC are you using ? I use 3.0.4.
I still have 2.95.3:
[pascal@thalassa]$ g++ --version
2.95.3
> How can you compile .c using g++ and .m using gcc
> in the same GNUmakefile ?
Actually, when specifying CC=g++ in GNUmakefile, the makefile system
of GNUstep will use g++ to compile everything, both .c and .m files.
> If I use CC=gcc++ at the beginning,
> it will complain that g++ unrecognize option '-MP'
> and cc1obj invalide option '-fconstant-string-class=NSConstantString'
> Here is what I have:
>
> g++ main.m -c \
> -MMD -MP -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1 ...
> -o shared_objc/ix86/freebsd/gnu-gnu-gnu/main.o
> ...
>
> So I use CC=gcc to get the .o file first.
> Then use CC=g++ again, I got the error in previous message...
>
> So weird... need to look into it....
The fact is, when you want to link C++ code with C (or Objective-C)
code, you have to take care of the name mangling done by the C++
compiler. One way to do it is to use only a C++ compiler, therefore
you only generate mangled names (for C and C++ objects) and there's no
linking problem. Another option is to use extern "C"{ ... } in C/C++
code. See attached files.
> Yen-Ju
>
> >From: Pascal Bourguignon <[EMAIL PROTECTED]>
> >Reply-To: <[EMAIL PROTECTED]>
> >To: [EMAIL PROTECTED]
> >CC: [EMAIL PROTECTED]
> >Subject: Re: Link to C++ library
> >Date: Tue, 10 Sep 2002 23:28:28 +0200 (CEST)
> >
> > > From: "Yen-Ju Chen" <[EMAIL PROTECTED]>
> > > Date: Tue, 10 Sep 2002 16:55:52 -0400
> > >
> > >
> > > Thanx a lot. It helps.
> > > But can I directly link Objective-C to C++ throught
> > > the C interface which the C++ library offers ?
> > >
> > > After apply the CC=g++, the error message becomes
> > >
> > > .../libgnustep-base.so: undefined reference to '__objc_msg_forward'
> > > .../libgnustep-base.so: undefined reference to '__objc_msg_thread_add'
> > > .../libgnustep-base.so: undefined reference to
> >'__objc_msg_thread_remove'
> > >
> > > Or do I need to write a C library as the bridge between Objective-C
> >and
> > > C++ ?
> >
> >You seem to be missing the Objective-C runtime. I still use a GNUstep
> >some months old, but it's makefiles automatically cite -lobjc on the
> >link line. I have something like:
> >
> > g++ -rdynamic \
> > -o MyApp.app/ix86/linux-gnu/gnu-gnu-gnu/MyApp \
> > shared_obj/ix86/linux-gnu/gnu-gnu-gnu/MyObjects.o ... \
> > -L/home/pascal/GNUstep/Libraries/ix86/linux-gnu/gnu-gnu-gnu \
> > -L/home/pascal/GNUstep/Libraries/ix86/linux-gnu \
> > -L/local/gnustep/Local/Libraries/ix86/linux-gnu/gnu-gnu-gnu \
> > -L/local/gnustep/Local/Libraries/ix86/linux-gnu \
> > -L/local/gnustep/Network/Libraries/ix86/linux-gnu/gnu-gnu-gnu \
> > -L/local/gnustep/Network/Libraries/ix86/linux-gnu \
> > -L/local/gnustep/System/Libraries/ix86/linux-gnu/gnu-gnu-gnu \
> > -L/local/gnustep/System/Libraries/ix86/linux-gnu \
> > -L/local/gnustep/System/Libraries/ix86/linux-gnu \
> > -lgnustep-gui -lgnustep-base -lobjc \
> > -lz -lcallback -lavcall -lxml2 -lz -lm -lgmp -lpthread -ldl -lm \
> > $(MyApp_OTHER_LIBRARIES)
> >
> >
> > > Thanx again.
> > >
> > > Yen-Ju
> > >
> > > >From: Pascal Bourguignon <[EMAIL PROTECTED]>
> > > >Date: Tue, 10 Sep 2002 22:38:13 +0200 (CEST)
> > > > > From: "Yen-Ju Chen" <[EMAIL PROTECTED]>
> > > > > Date: Tue, 10 Sep 2002 15:52:52 -0400
> > > > >
> > > > > I try to use the id3lib (http://www.id3lib.org), which is a
> > > > > C++ library, but offer the C interface. But I met a problem
> > > > > about linking between id3lib and standard C++ library. Is it
> > > > > possible to use such C++ library with C interface in GNUstep ?
> > > >
> > > >I do link routinely C++ libraries into GNUstep / Objective-C
> > > >applications without any problem, passing thru a C interface.
> > > >
> > > >Here is an example of GNUmakefile I used lately. The only notable
> > > >thing is the use of the g++ compiler (CC=g++) to compile the
> > > >MyCppLibCalls.c file, which contains only simple C functions each
> > > >sending a message to a C++ object from libMyCppLib.a, which is a
> > > >library of C++ objects.
--
__Pascal_Bourguignon__ http://www.informatimago.com/
----------------------------------------------------------------------
The name is Baud,...... James Baud.
#ifndef stuff_h
#define stuff_h
#ifdef __cplusplus
extern "C" {
#endif
extern void* f_stuff_new(void);
extern int f_stuff_message(void* obj,int a);
#ifdef __cplusplus
}
#endif
#endif
#ifndef stuff_hpp
#define stuff_hpp
class Stuff
{
public:
int x;
int message(int a);
};
#endif
#include <stdio.h>
#include "stuff.h++"
#include "stuff.h"
int Stuff::message(int a)
{
x=a;
return(x+1);
}
void* f_stuff_new(void)
{
return(new Stuff);
}
int f_stuff_message(void* obj,int a)
{
return(((Stuff*)obj)->message(a));
}
#ifdef STANDALONE
int main(void)
{
Stuff* stuff=new Stuff;
printf("first =%d\n",stuff->message(1));
printf("second=%d\n",f_stuff_message((void*)stuff,2));
return(0);
}
#endif
#include "stuff.h"
int main(void)
{
void* stuff=f_stuff_new();
printf("third =%d\n",f_stuff_message(stuff,3));
return(0);
}
all:test-c++ test-objc
test:all
nm test-c++
nm test-objc
./test-c++
./test-objc
test-c++:stuff.c++ stuff.h++ stuff.h
g++ -DSTANDALONE -o test-c++ stuff.c++
stuff.o:stuff.c++ stuff.h++ stuff.h
g++ -c -o stuff.o stuff.c++
main.o:main.m stuff.h
gcc -c -o main.o main.m
test-objc:stuff.o main.o
nm stuff.o
nm main.o
gcc -o test-objc stuff.o main.o
cd /home/pascal/tmp/
make test
g++ -DSTANDALONE -o test-c++ stuff.c++
g++ -c -o stuff.o stuff.c++
gcc -c -o main.o main.m
nm stuff.o
00000000 ? __FRAME_BEGIN__
U __builtin_new
00000050 T f_stuff_message
00000020 T f_stuff_new
00000000 t gcc2_compiled.
00000000 T message__5Stuffi
nm main.o
00000000 d _OBJC_SELECTOR_TABLE
U f_stuff_message
U f_stuff_new
00000000 t gcc2_compiled.
00000000 T main
U printf
gcc -o test-objc stuff.o main.o
nm test-c++
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w __register_frame_info
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nm test-objc
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08050694 ? _GLOBAL_OFFSET_TABLE_
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08050528 ? __EXCEPTION_TABLE__
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0804a6f0 T __cp_pop_exception
0804a680 T __cp_push_exception
0804a610 T __cplus_type_matcher
w __cxa_finalize@@GLIBC_2.1.3
0804e964 D __data_start
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08049c70 T __get_eh_table_language
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w __gmon_start__
0804e97c d __gthread_active_ptr
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0804c470 T __is_pointer__FPv
U __libc_start_main@@GLIBC_2.0
0804cf20 W __ne__C9type_infoRC9type_info
08050818 B __new_handler
0804ce60 W __nw__FUiPv
0804b6e0 T __register_frame
0804b660 T __register_frame_info
0804b720 T __register_frame_info_table
0804b7a0 T __register_frame_table
0804a390 T __rethrow
0804c600 T __rtti_array
0804c500 T __rtti_attr
0804bcc0 T __rtti_class
0804c540 T __rtti_func
0804c5c0 T __rtti_ptmd
0804c580 T __rtti_ptmf
0804c4c0 T __rtti_ptr
0804bd10 T __rtti_si
0804bd60 T __rtti_user
08049b00 T __sjpopnthrow
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0804a570 T __start_cp_handler
080496c0 T __terminate
0804e980 D __terminate_func
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0804d6a0 W __tf16__ptmd_type_info
0804d620 W __tf16__ptmf_type_info
0804d100 W __tf16__user_type_info
0804d720 W __tf17__array_type_info
0804d300 W __tf17__class_type_info
0804d520 W __tf19__builtin_type_info
0804d420 W __tf19__pointer_type_info
0804cf50 W __tf8bad_cast
0804cdf0 W __tf9bad_alloc
0804cc20 W __tf9exception
0804cea0 W __tf9type_info
0804cb90 T __tfSc
0804cb40 T __tfUc
0804ca00 T __tfUi
0804ca50 T __tfUl
0804caf0 T __tfUs
0804caa0 T __tfUx
0804c820 T __tfb
0804c870 T __tfc
0804c960 T __tfd
0804c9b0 T __tff
0804c780 T __tfi
0804c730 T __tfl
0804c910 T __tfr
0804c7d0 T __tfs
0804c690 T __tfv
0804c8c0 T __tfw
0804c6e0 T __tfx
0804a2d0 T __throw
0804a9b0 T __throw_bad_cast
0804aa50 T __throw_bad_typeid
080496f0 T __throw_type_match
0804bfd0 T __throw_type_match_rtti
080508c4 B __ti10bad_typeid
080508a4 B __ti13bad_exception
080508f0 B __ti14__si_type_info
08050914 B __ti16__attr_type_info
08050908 B __ti16__func_type_info
08050944 B __ti16__ptmd_type_info
08050920 B __ti16__ptmf_type_info
080508e4 B __ti16__user_type_info
0805092c B __ti17__array_type_info
080508fc B __ti17__class_type_info
08050950 B __ti19__builtin_type_info
08050938 B __ti19__pointer_type_info
080508d0 B __ti8bad_cast
080508b8 B __ti9bad_alloc
080508b0 B __ti9exception
080508dc B __ti9type_info
0805089c B __tiSc
08050894 B __tiUc
08050874 B __tiUi
0805087c B __tiUl
0805088c B __tiUs
08050884 B __tiUx
08050844 B __tib
0805084c B __tic
08050864 B __tid
0805086c B __tif
08050834 B __tii
0805082c B __til
0805085c B __tir
0805083c B __tis
0805081c B __tiv
08050854 B __tiw
08050824 B __tix
0804a7a0 T __uncatch_exception
0804e98c d __unexpected_func
08049f40 T __unwinding_cleanup
0804ce80 W __vn__FUiPv
0804ea24 V __vt_10bad_typeid
0804e9ac V __vt_13bad_exception
0804e9fc V __vt_14__si_type_info
0804eaac V __vt_16__attr_type_info
0804ea8c V __vt_16__func_type_info
0804ea6c V __vt_16__ptmd_type_info
0804ea7c V __vt_16__ptmf_type_info
0804ea10 V __vt_16__user_type_info
0804ea5c V __vt_17__array_type_info
0804e9e8 V __vt_17__class_type_info
0804ea9c V __vt_19__builtin_type_info
0804eabc V __vt_19__pointer_type_info
0804ea38 V __vt_8bad_cast
0804e9d4 V __vt_9bad_alloc
0804e9c0 V __vt_9exception
0804ea4c V __vt_9type_info
080507dc A _edata
0805095c A _end
0804d770 ? _fini
0804d7a0 R _fp_hw
08049250 ? _init
08049390 T _start
U abort@@GLIBC_2.0
0804aea0 t add_fdes
0804bf90 T before__C9type_infoRC9type_info
080493b4 t call_gmon_start
0804e970 d completed.4
08049e60 t copy_reg
0804ae70 t count_fdes
0804e964 W data_start
0804bde0 T dcast__C14__si_type_infoRC9type_infoiPvPC9type_infoT3
0804bda0 T dcast__C16__user_type_infoRC9type_infoiPvPC9type_infoT3
0804be40 T dcast__C17__class_type_infoRC9type_infoiPvPC9type_infoT3
0804abb0 t decode_sleb128
0804ab60 t decode_uleb128
080507f4 b eh.127
08049790 t eh_context_free
08049880 t eh_context_initialize
08050810 b eh_context_key
08049950 t eh_context_specific
080498f0 t eh_context_static
08049830 t eh_threads_initialize
0804ac80 t end_fde_sort
0804b270 t execute_cfa_insn
0804b110 t extract_cie_info
080494e0 T f_stuff_message
080494b0 T f_stuff_new
0804ac00 t fde_merge
0804ba50 t fde_split
08049d20 t find_exception_handler
0804b050 t find_fde
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0804e9ac d force_to_data
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08049450 t frame_dummy
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U free@@GLIBC_2.0
080493b4 t gcc2_compiled.
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w pthread_key_create
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w pthread_mutex_trylock
w pthread_mutex_unlock@@GLIBC_2.0
w pthread_once
w pthread_setspecific
0804bb60 T set_new_handler__FPFv_v
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./test-c++
first =2
second=3
./test-objc
third =4
Compilation finished at Wed Sep 11 01:20:27
