On 06/19/2015 11:36 AM, Paolo Bonzini wrote: > On 09/06/2015 16:22, Michael Haubenwallner wrote: >> Hi build machinery maintainers, >> >> since we always build the C++ compiler now, I fail to see the need to still >> use RAW_CXX_TARGET_EXPORTS for libvtv. >> >> The situation to expose the problem is: >> * Use a multilib-enabled x86_64-linux box. >> * Use a 64-bit (multilib-disabled) bootstrap compiler (binary image). >> $ configure --enable-multilib --with-system-zlib >> $ make bootstrap >> >> When it comes to build the 32-bit libvtv, it breaks because of using >> "CC=/build/prev-gcc/xgcc -m32" "CXX=g++ -m32", while it should use >> "CC=/build/prev-gcc/xgcc -m32" "CXX=/build/prev-gcc/xg++ -m32" instead.
Unfortunately, I've been unable to reproduce this problem for a while now, and it turns out that I also used --enable-maintainer-mode. And it happens only when some generated autotool-file is updated while it is in use - not really sure which one though, probably some configure script. But still: >> However, I'm not sure about the general question behind: >> Should it work to bootstrap the multilib-compiler using a non-multilib one? >> >> This also needs above configure flags to work around two more but minor >> issues, >> which I'm unsure about whether I can/should fix at all: >> * --enable-multilib: Without this, the "user friendly check" is breaking, >> since https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=205975 > > Why is it breaking? The OS I'm running on is a multilib-enabled x86_64 (Gentoo) Linux, and "32-bit development libraries (libc and headers)" are available. The compiler I want to bootstrap the multilib compiler with is an x86_64-only binary image (c,c++,ada), built _without_ multilib. Now this "user friendly check" tries to create a 32-bit executable using that 64-bit-only bootstrap gcc, which lacks 32-bit libgcc* - while it can create 32-bit object files though. >> * --with-system-zlib: Without this, --enable-multilib tries to build a >> 32-bit zlib with "CC=/build/32/./prev-gcc/xgcc" > > Ouch, that's a separate bug... Arguably --with-system-zlib should be > the default these days (and should have been for 10 years or so). This one I'll leave untouched. > The patch is ok. Even if the problem raises only because maintainer-mode isn't multilib-save? Thanks! /haubi/
