On 03 Jan 2007 10:07:57 -0800, Ian Lance Taylor <[EMAIL PROTECTED]> wrote:
Adam Sulmicki <[EMAIL PROTECTED]> writes:> In spirit making OSS better, I took the extra effor to report > findings back to both lists. In reward I got flamed on both list. You got flamed on the gcc list? I don't see any flames there. All I told you was to use the gcc-help mailing list, which was correct. We have different mailing lists for a reason. Sending e-mail to the wrong list simply wastes people's time. I also did my best to answer your question. In your original message you didn't mention that there was an mcount variable in your program, so it's not surprising that I wasn't able to identify the problem. > * Rename mcount in mplayer/libmenu/menu.c to something else. > > * document mcount in gcc man page > > * gcc prints warning. > > * do nothing. > > I can immagine that gcc developers might have intentionally left > mcount() visible to user space so that user can replace gcc's mcount() > with their own implementation. gcc does not provide the function which in this case is called mcount(). That function comes from the C library. The C library used on GNU/Linux systems, glibc, actually provides the function _mcount, with a weak alias named mcount. So this seems to be a bug in gcc: it should be calling _mcount. In fact, by default, gcc for the i386 targets will call _mcount. gcc for i386 GNU/Linux targets was changed to call mcount instead of _mcount with this patch: Thu Mar 30 06:20:36 1995 H.J. Lu ([EMAIL PROTECTED]) * configure (i[345]86-*-linux*): Set xmake_file=x-linux, tm_file=i386/linux.h, and don't set extra_parts. (i[345]86-*-linux*aout*): New configuration. (i[345]86-*-linuxelf): Deleted. * config/linux{,-aout}.h, config/x-linux, config/xm-linux.h: New files. * config/i386/linux-aout.h: New file. * config/i386/linux.h: Extensive modifications to use ELF format as default. (LIB_SPEC): Don't use libc_p.a for -p. don't use libg.a unless for -ggdb. (LINUX_DEFAULT_ELF): Defined. * config/i386/linuxelf.h,config/i386/x-linux: Files deleted. * config/i386/xm-linux.h: Just include xm-i386.h and xm-linux.h. I believe that was during the time H.J. was maintaining a separate branch of glibc for GNU/Linux systems. Presumably his version provided mcount but not _mcount. I haven't tried to investigate further. In any case clearly gcc for i386 GNU/Linux systems today should call _mcount rather than mcount. I will make that change.
I remember someone wanting to provide his own mcount(). Presumably, mcount() is weak in libc to cover such a use case ? -- #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";
