Boostrapping Ada and D support within LFS 12.2

In the LFS book, GCC is only built with C and C++ support.

There are many additional languages that can be built. Two of them, Ada (GCC gnat) and D (GCC gdc), require the GCC compiler used to build them already have Ada and D support.

The host distribution I used to build LFS 12.2 (LFS 11.3) has them, added by me previously, but the stripped down GCC used to build the LFS tools that then builds LFS is not built with Ada and D support, so GCC with Ada and D support has to be bootstrapped after building LFS 12.2.

So...to get Ada and D into my LFS 12.2/YJL Environment:

Step One: Build Ada enabled GCC 12.2 in LFS 11.3

In LFS 11.3, I used the Ada and D capable GCC 12.3.0 to compile an Ada and D capable GCC 14.2.0. This was done using the script build-pre-bootstrap.sh (in this git) within my LFS 11.3 system.

The GCC 14.2.0 the script built in LFS 11.3 has an install target of /opt/gcc-prebootstrap and was only built with support for c,c++,d, and ada.

Once built, the directory /opt/gcc-preboostrap was packed into a tarball to be unpacked in the same location in the LFS 12.2 environment.

Note that (other than glibc) GCC only has three library dependencies outside of GCC itself:

• MPFR (libmpfr.so.6 in LFS 12.2)
• GMP (libgmp.so.10, libgmpxx.so.4 in LFS 12.2)
• MPC (libmpc.so.3 in LFS 12.2)

Since those are the same ABI versions in LFS 11.3, I did not need to worry about copying the the LFS 11.3 versions into /opt/gcc-preboostrap/lib.

The tarball was unpacked into LFS 12.2 for Step Two. The file /etc/ld.so.conf.d/gcc-prebootstrap.conf was created containing:

/opt/gcc-preboostrap/lib

I then ran ldconfig as root so the linker knew where the libraries are.

To test that it working in LFS 12.2, I added /opt/gcc-prebootstrap/bin to my $PATH and compiled the hello.adb program:

gnatmake hello.adb

The program compiled without a segfault and ran without a segfault so I knew I was probably good to go.

Step Two: Build Ada and D enabled GCC 14.2.0 in LFS 12.2

Theoretically this step could be skipped and I could have built the system GCC without this step but I would rather be safe.

Using the /opt/gcc-preboostrap build of GCC 14.2.0 as the compiler, I did an identical build within LFS 12.2 but using /opt/gcc-bootstrap as the install prefix. This was done with the script build-bootstrap.sh (in this git) within my LFS 12.2 system.

In this case, since I was building the compiler that would then build the system compiler, I did run the test suite after it finished (and it takes a long time).

There were a few unexpected errors but when building GCC there always are. The tests that had unexpected errors are shown below:

                === libphobos Summary ===

# of expected passes            412
# of unexpected failures        3

...

                === libphobos Summary ===

# of expected passes            389
# of unexpected failures        1

...

                === gcc Summary ===

# of expected passes            88026
# of unexpected failures        2
# of expected failures          776
# of unsupported tests          1611

...

                === g++ Summary ===

# of expected passes            15870
# of unexpected failures        2
# of expected failures          32
# of unsupported tests          209

Summaries from the log file without unexpected failures are not shown. I was very happy with the test results.

Once built and installed, I did make a tarball of /opt/gcc-bootstrap just in case I screw the system up and need to re-install LFS 12.2, I can then use that tarball to go straight to Step Three.

The /opt/gcc-prebootstrap directory was then deleted and the /etc/ld.so.conf.d/gcc-prebootstrap.conf file was renamed to /etc/ld.so.conf.d/gcc-bootstrap.conf with the path in it updated to point to /opt/gcc-preboostrap/lib, of course re-running ldconfig afterwards.

The system is now ready to build the Ada and D capable GCC as the system GCC with an install prefix of /usr.

Step Three: Build Ada and D enabled GCC 14.2.0 with /usr prefix

Step three replaced the original LFS build of GCC with a build that supports Ada and D, using the GCC built in Step Two. This was done using the script CH08.27-gcc-modified.sh (in this git) within my LFS 12.2 system.

The build used the same build options as the LFS Chapter 8 build of GCC except with the following configure options removed:

--enable-languages=c,c++ \
--disable-bootstrap      \
--enable-host-pie        \

and the following configure options added:

--enable-linker-build-id \
--enable-languages=c,c++,ada,d

The --disable-bootstrap option was removed because despite bootstrap builds taking a much longer time, it is generally recommended. BLFS also removes that configure option so GCC does an internal bootstrap.

The --enable-host-pie option was removed because it causes a build failure when compiling many of the languages beyong c and c++, including Ada. BLFS also does not use that configure option.

The --enable-linker-build-id option was added because RPM will need it to make debug packages.

As with Step Two, there were very few errors in the make -k check log and the errors that were there were the same. The build is a good build.

Phase Two of THE-PLAN.md is complete. /opt/gcc-bootstrap was deleted and the /etc/ld.so.conf.d/gcc-bootstrap.conf file was removed.

Future GCC Build

During ‘Phase Four’ of THE-PLAN.md (RPM Bootstrap), GCC will be rebuilt as RPM packages. During that rebuild, support for all the other languages GCC supports will also be built.