$NetBSD: README,v 1.8 2018/06/01 21:46:18 mrg Exp $
GMP in NetBSD. We need GMP for GCC >= 4.2.
Building GMP without configure - how to port GMP build to a new platform.
The GMP build doesn't map very well to normal make. The ./configure phase
creates a bunch of symlinks and weeds out the sources lists, and there are
files with the same name in different subdirectories linked into the same
final product. All of these issues need to be dealt with.
There are a few steps to this:
- run ./configure, save the output. you can use the makefile
"Makefile.netbsd-gmp" in this directory to run this with the
right options, etc. run it with nbmake-$MACHINE.
- create src/external/gpl3/gmp/lib/libgmp/arch/${MACHINE_ARCH} dir,
and copy these files into it:
config.h
config.m4
gmp-mparam.h
gmp.h
some of these files might have src/obj references. in particular
fix GMP_MPARAM_H_SUGGEST to start from ./mpn/... and make sure
we #define __GMP_CC to just "gcc", and make sure that
CONFIG_TOP_SRCDIR is not defined in config.m4
the "Makefile.netbsd-gmp" has a "copy-files" target that performs
these tasks.
- parse the ./configure output and note all created symlinks
for mpn. these need to be converted into a new Makefile.inc.
there is a script in this subdir build-gmp-Makefile.inc.awk
that can be used to do this. it should just work to generate
the first section of Makefile.inc if fed the entire configure
output.
assembler files generally want -DOPERATION_${foo} defined for
each way they are compiled or pre-processed. the pre-processor
used is m4 to parse, and we and create .s files from the .asm
files that we then we feed into $CC.
this part needs to be automated, but requires that the first
part's ./configure output be stored for it. this is not done.
it would be good to convert the Makefile.inc into a pair of
files -- srcs.mk generated from build-gmp-Makefile.inc.awk, and
the remaining static part of the Makefile.inc left with the
include of srcs.mk.
The amd64 port is a good reference to compare.
This is still a work in progress and methods used to build may be
changed at any time.
mrg@netbsd.org
- 2017/08/22
d1429afe98