Modify the cross-compiling shell script to configure GCC for building GCC with C++ support when building its second (i.e., final) version.

Compiling a most-trivial C++ program used to work with GCC 4.2 and 4.3 (and the resulting binaries would also work), but linking fails with GCC SVN trunk:

$ $TARGET-g++ -Wall a.cc -lpthread
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__multf3'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__fixunstfsi'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__subtf3'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__divtf3'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__copysigntf3'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__addtf3'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__lttf2'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__floatsitf'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__netf2'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__floatunsitf'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__eqtf2'
/home/thomas/tmp/gnu-0/lib/gcc/i586-pc-gnu/4.4.0/../../../../i586-pc-gnu/lib/libgcc_s.so: undefined reference to `__fabstf2'
collect2: ld returned 1 exit status

Whether this defect report also applies to a natively-build GCC from SVN trunk has not yet been checked.

Thomas Schwinge suspects the problem to be a configuration issue of a GCC helper library, whose configuration setup has changed after GCC 4.3.

The need for -lpthread is another story. See the Debian glibc patches repository for details.

For GCC trunk:

Debian package has patches (for 4.3). Some have been forwarded upstream. (And have been ignored.) Thomas Schwinge is working on getting them integrated.

• [meta-bug] bootstrap bugs for *-gnu*

• build system: gcc_cv_libc_provides_ssp and NATIVE_SYSTEM_HEADER_DIR

• -fstack-protector shouldn't use TLS in freestanding mode

• Tool chain configuration: GNU/* sharing stuff with GNU/Linux

Additionally:

• Configure fragments that have *linux* cases might/should often contain those for us (and GNU/k*BSD) as well.

  • libgcc/configure.ac might need to be aligned for us to the *linux* cases. As well as at the end of libgcc/config.host. Check.

    checking whether decimal floating point is supported... no
    checking whether fixed-point is supported... no
    

  • libgomp/configure.tgt

• libmudflap.

• C++.