Re: How do I add missing stdc functions to libstdc++-v3?
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On 2012-03-12, at 9:19 PM, Jonathan Wakely wrote: > On 13 March 2012 00:14, Vaugha Brewchuk wrote: >> I have done a bit more experimenting and have made small progress. I tried linking abi_check manually while adding an object including strdup(). As a result, my original error message changed from: >> >> /bin/ld: Undefined symbols: >> access(char const*, int) >> ___gxx_personality_sj0 >> ___cxa_call_unexpected >> strxfrm(char*, char const*, unsigned long) >> strdup(char*) >> write(int, void const*, unsigned long) >> _strdup >> >> to: >> >> /bin/ld: Undefined symbols: >> access(char const*, int) >> ___gxx_personality_sj0 >> ___cxa_call_unexpected >> strxfrm(char*, char const*, unsigned long) >> strdup(char*) >> write(int, void const*, unsigned long) >> >> So the actual linker error relating to missing "_strdup" disappeared, but the error with "strdup(char*)" remained. I then edited my system headers to add the missing definitions for access(), strxfrm(), strdup() and write() and rebuilt gcc-3.2.3 from scratch (it takes around 20 hours on a 68040!). Subsequent manual linking of abi_check only complained about two missing symbols: >> >> /bin/ld: Undefined symbols: >> ___gxx_personality_sj0 >> ___cxa_call_unexpected >> >> Could someone please indicate to me at what point in gcc configuration (or build) the system headers are scanned for presence or absence of functions? Where do I tweak the gcc source to be able to define these missing functions without the need for editing my system headers? I tried to search the sources and the build directories, but was not successful in finding anything obviously related. >> >> Finally, how and where are the missing two symbols "___gxx_personality_sj0" and "___cxa_call_unexpected" normally generated? And again, where in the code do I need to start looking to define a workaround? > > They should be defined by gcc itself, in libsupc++.so, you shouldn't > have to do anything. > > How are you linking abi_check? What exact command? > > I think the problem is how you're linking, not missing features of the OS. You were absolutely correct regarding the linking phase. I am using the exact same command as the Makefile with the all-target-libstdc++-v3 target: /Storage2/gcc-3.2.3-bld/gcc/g++ -shared-libgcc -B/Storage2/gcc-3.2.3-bld/gcc/ -nostdinc++ -B/usr/local/m68k-next-nextstep3/bin/ -B/usr/local/m68k-next-nextstep3/lib/ -isystem /usr/local/m68k-next-nextstep3/include -g -O2 -o abi_check abi_check.o -L/Storage2/gcc-3.2.3-bld/m68k-next-nextstep3/libstdc++-v3/src -L/Storage2/gcc-3.2.3-bld/m68k-next-nextstep3/libstdc++-v3/src/.libs -lm With verbose output enabled, the command produces the following output: Reading specs from /Storage2/gcc-3.2.3-bld/gcc/specs Configured with: ../gcc-3.2.3/configure --prefix=/usr/local --enable-languages=c,objc,c++,f77 --disable-shared --disable-threads --enable-cpp --enable-obsolete m68k-next-nextstep3 Thread model: single gcc version 3.2.3 /Storage2/gcc-3.2.3-bld/gcc/collect2 -o abi_check -lcrt0.o -L/Storage2/gcc-3.2.3-bld/m68k-next-nextstep3/libstdc++-v3/src -L/Storage2/gcc-3.2.3-bld/m68k-next-nextstep3/libstdc++-v3/src/.libs -L/Storage2/gcc-3.2.3-bld/gcc -L/usr/local/lib/gcc-lib/m68k-next-nextstep3/3.2.3 -L/usr/local/lib/gcc-lib/m68k-next-nextstep3/3.2.3/../../.. abi_check.o -lstdc++ -lm -lgcc -lsys_s -lgcc /bin/ld: Undefined symbols: access(char const*, int) ___gxx_personality_sj0 strdup(char const*) ___cxa_call_unexpected _strdup strxfrm(char*, char const*, unsigned long) collect2: ld returned 1 exit status Following your suggestions and looking at the above output, it is obvious that there is no -lsupc++ command passed-on to collect2. I manually added -lsupc++ to the above command and both of the missing symbols have been imported by the linker! I am now one step closer to getting abi_check linked - thank you! Now the question is why does g++ not try to link with libsupc++.a? I will dig through the configuration, but as always any pointers would be very much appreciated. And of course I still get this even with all the symbols resolved by the linker: /bin/ld: Undefined symbols: access(char const*, int) strdup(char const*) strxfrm(char*, char const*, unsigned long) collect2: ld returned 1 exit status Thank you once again!