Maurice Leclaire wrote: > Hi, > > I am new to LFS. During chapter 5 GCC pass 2 I stumbled across the > following issue: > > Building with the instructions from the book just worked, but I thought > instead of specifying all programs on the command line, configuring > binutils pass 2 and gcc pass 2 with > > --target=$LFS_TGT --host=$LFS_TGT --build=$([...]/config.guess) > > could be a good idea as gcc pass 1 is a cross compiler. Indeed, this did > the expected changes in the Makefile, but ... > GCC (more precisely libstdc++-v3) failed to compile.
We have just released LFS-7.3 and will wait until gcc-4.8 to address building with g++. At that time, the fixes to the .texi files should already be incorporated. > This shows that libstdc++-v3 needs a C++ compiler, which obviously > cannot be found in this case. I assume that when using the book > instructions the C++ compiler of the host system is used, but wouldn't > that defeat the goal of leaving the host system? > > I actually wanted to use these configure switches (maybe this is just > personal preference) and ensure that no host compiler is used at this > point. After I already solved this, I found the following thread on a > related topic. > http://thread.gmane.org/gmane.linux.lfs.devel/13574 > It explains two possible ways of building GCC with C++. Because both > methods have a few drawbacks, I thought of posting my solution, too. > > This solution involves a bit more compile time, but I think it is a > fairly clean way of leaving the host system behind. > > 1. Binutils pass 1, GCC pass 1, Linux headers and Glibc are built as > instructed in the book. > > 2. A second cross GCC is built this time with C++ enabled, linking > already against the new Glibc. > > 3. Binutils and GCC are built both with the --target,--host,--build > configure switches (obsoleting the environment variables and > --disable-bootstrap). > > This worked quite well for me until the end of chapter 6 (all I did up > to now). > > Just wanted to let you know of this possible (probably harmless) > contamination of the toolchain through the C++ compiler of the host. Your changes are probably fine as building inside a chroot will isolate everything from the host to what is in /tools. -- Bruce -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
