In a normal GCC build the top-level Makefile automatically sets the
CXX=xgcc. And without it the "checking for sin in -lm" probe will fail,
and then GCC will believe the math functions (for example acosf) are not
available and fail to build std.gcm (added since GCC 16) with about a
dozen lines of error messages, which would likely disconcert the user if
spotted.
They are really harmful. In Binutils pass 2, libstdc++.la caused the
building system to use host /usr/lib/libstdc++.so for gprofng. We now
has disabled gprofng for pass 2, but the similar issue also exists in
GCC pass 2. In a normal LFS build, the building system silently uses
/usr/lib/libstdc++.so (I guess it does not blow up simply because some
blind luck); in a real cross build (x86 -> ARM for example) the build
will fail.
Remove the .la files to fix this issue. Instead of only modifying
clfs-ng, it makes more sense to apply the change for trunk: though
the build does not fail, using host library is still a contamination.
This is the issue preventing us from cross-compiling libstdc++ in
Chapter 6. By fixing this issue we can remove a seperate pass 2 for
libstdc++ and simplify the instruction.
The upstream fix will be released in 11.3 and 12.0, so we can remove the
first sed upgrading gcc next time.
Thanks to Ken Moffat for identifying the proplem and the fix.
Fixed Ncurses and Perl build with GCC 5. Thanks to Ken Moffat and
Douglas R. Reno for providing the patches.
Updated to GCC-5.1.0. Imported changes from systemd version.
git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@10903 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
Fix typo in Chapter 5, libstdc++.
Removed obsolete reference to acinstall in automake section.
Removed obsolete reference to sbu home page in Chapter 4.
Update installed programs for gdbm.
git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@10556 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
