/* doc/configuration (in Emacs -*-outline-*- format). */ Copyright 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of the GNU MP Library. The GNU MP Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU MP Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU MP Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * Adding a new file ** Adding a top-level file i) Add it to libgmp_la_SOURCES in Makefile.am. ii) If libmp.la needs it (usually doesn't), then add it to libmp_la_SOURCES too. ** Adding a subdirectory file For instance for mpz, i) Add file.c to libmpz_la_SOURCES in mpz/Makefile.am. ii) Add mpz/file$U.lo to MPZ_OBJECTS in the top-level Makefile.am iii) If for some reason libmp.la needs it (usually doesn't) then add mpz/file$U.lo to libmp_la_DEPENDENCIES in the top-level Makefile.am too. The same applies to mpf, mpq, scanf and printf. ** Adding an mpn file The way we build libmpn (in the `mpn' subdirectory) is quite special. Currently only mpn/mp_bases.c is truely generic and included in every configuration. All other files are linked at build time into the mpn build directory from one of the CPU specific sub-directories, or from the mpn/generic directory. There are four types of mpn source files. .asm Assembly code preprocessed with m4 .S Assembly code preprocessed with cpp .s Assembly code not preprocessed at all .c C code There are two types of .asm files. i) ``Normal'' files containing one function, though possibly with more than one entry point. ii) Multi-function files that generate one of a set of functions according to build options. To add a new implementation of an existing function, i) Put it in the appropriate CPU-specific mpn subdirectory, it'll be detected and used. ii) Any entrypoints tested by HAVE_NATIVE_func in other code must have PROLOGUE(func) for configure to grep. This is normal for .asm or .S files, but for .c files a dummy comment like the following will be needed. /* PROLOGUE(func) */ To add a new implementation using a multi-function file, in addition do the following, i) Use a MULFUNC_PROLOGUE(func1 func2 ...) in the .asm, declaring all the functions implemented, including carry-in variants. If there's a separate PROLOGUE(func) for each possible function (but this is usually not the case), then MULFUNC_PROLOGUE isn't necessary. To add a new style of multi-function file, in addition do the following, i) Add to the GMP_MULFUNC_CHOICES "case" statement in configure.in which lists each multi-function filename and what function files it can provide. To add a completely new mpn function file, do the following, i) Ensure the filename is a valid C identifier, due to the -DOPERATION_$* used to support multi-function files. This means "-" can't be used (but "_" can). ii) Add it to configure.in under one of the following a) `gmp_mpn_functions' if it exists for every target. This means there must be a C version in mpn/generic. (Eg. mul_1) b) `gmp_mpn_functions_optional' if it's a standard function, but doesn't need to exist for every target. Code wanting to use this will test HAVE_NATIVE_func to see if it's available. (Eg. copyi) c) `extra_functions' for some targets, if it's a special function that only ever needs to exist for certain targets. Code wanting to use it can test either HAVE_NATIVE_func or HAVE_HOST_CPU_foo, as desired. iii) If HAVE_NATIVE_func is going to be used, then add a #undef to the AH_VERBATIM([HAVE_NATIVE] block in configure.in. iv) Add file.c to nodist_libdummy_la_SOURCES in mpn/Makefile.am (in order to get an ansi2knr rule). If the file is only in assembler then this step is unnecessary, but do it anyway so as not to forget if later a .c version is added. v) If the function can be provided by a multi-function file, then add to the "case" statement in configure.in which lists each multi-function filename and what function files it can provide. ** Adding a test program i) Tests to be run early in the testing can be added to the main "tests" sub-directory. ii) Tests for mpn, mpz, mpq and mpf can be added under the corresponding tests subdirectory. iii) Generic tests for late in the testing can be added to "tests/misc". printf and scanf tests currently live there too. iv) Random number function tests can be added to "tests/rand". That directory has some development-time programs too. v) C++ test programs can be added to "tests/cxx". A line like the following must be added for each, since by default automake looks for a .c file. t_foo_SOURCES = t-foo.cc In all cases the name of the program should be added to check_PROGRAMS in the Makefile.am. TESTS is equal to check_PROGRAMS, so all those programs get run. "tests/devel" has a number of programs which are only for development purposes and are not for use in "make check". These should be listed in EXTRA_PROGRAMS to get Makefile rules created, but they're never built or run unless an explicit "make someprog" is used. ** Macos directory The macos/configure script will automatically pick up additions to gmp_mpn_functions, MPZ_OBJECTS, etc, but currently test programs need to be added to Makefile.in manually. When modifying the top-level configure.in ensure that it doesn't upset the macos/configure script heuristics. Unfortunately there's no way to test this stuff without getting an actual MacOS 9 system. * Adding a new CPU In general it's policy to use proper names for each CPU type supported. If two CPUs are quite similar and perhaps don't have any actual differences in GMP then they're still given separate names, for example alphaev67 and alphaev68. Canonical names: i) Decide the canonical CPU names GMP will accept. ii) Add these to the config.sub wrapper if configfsf.sub doesn't already accept them. iii) Document the names in gmp.texi. Aliases (optional): i) Any aliases can be added to the config.sub wrapper, unless configfsf.sub already does the right thing with them. ii) Leave configure.in and everywhere else using only the canonical names. Aliases shouldn't appear anywhere except config.sub. iii) Document in gmp.texi, if desired. Usually this isn't a good idea, better encourage users to know just the canonical names. Configure: i) Add patterns to configure.in for the new CPU names. Include the following (see configure.in for the variables to set up), a) ABI choices (if any). b) Compiler choices. c) mpn path for CPU specific code. d) Good default CFLAGS for each likely compiler. d) Any special tests necessary on the compiler or assembler capabilities. ii) M4 macros to be shared by asm files in a CPU family are by convention in a foo-defs.m4 like mpn/x86/x86-defs.m4. They're likely to use settings from config.m4 generated by configure. Fat binaries: i) In configure.in, add CPU specific directory(s) to fat_path. ii) In mpn//fat.c, identify the CPU at runtime and use suitable CPUVEC_SETUP_subdir macros to select the function pointers for it. iii) For the x86s, add to the "$tmp_prefix" setups in configure.in which abbreviates subdirectory names to fit an 8.3 filesystem. (No need to restrict to 8.3, just ensure uniqueness when truncated.) * The configure system ** Installing tools The current versions of automake, autoconf and libtool in use can be checked in the ChangeLog. Look for "Update to ...". Patches may have been applied, look for "Regenerate ...". The GMP build system is in places somewhat dependent on the internals of the build tools. Obviously that's avoided as much as possible, but where it can't it creates a problem when upgrading or attempting to use different tools versions. ** Updating gmp The following files need to be updated when going to a new version of the build tools. Unfortunately the tools generally don't identify when an out-of-date version is present. aclocal.m4 is updated by running "aclocal". (Only needed for a new automake or libtool.) INSTALL.autoconf can be copied from INSTALL in autoconf. ltmain.sh comes from libtool. Remove it and run "libtoolize --copy", or just copy the file by hand. ansi2knr.c, ansi2knr.1, install-sh and doc/mdate-sh come from automake and can be updated by copying or by removing and running "automake --add-missing --copy". texinfo.tex can be updated from ftp.gnu.org. Check it still works with "make gmp.dvi", "make gmp.ps" and "make gmp.pdf". configfsf.guess and configfsf.sub can be updated from ftp.gnu.org (or from the "config" cvs module at subversions.gnu.org). The gmp config.guess and config.sub wrappers are supposed to make such an update fairly painless. depcomp from automake is not needed because configure.in specifies automake with "no-dependencies". ** How it works During development: Input files Tool Output files --------------------------------------------------------- aclocal $prefix/share/aclocal*/*.m4 ----------------> aclocal.m4 configure.in \ autoconf aclocal.m4 / -----------------------------> configure */Makefile.am \ automake configure.in | ----------------------------> Makefile.in aclocal.m4 / configure.in \ autoheader aclocal.m4 / -----------------------------> config.in At build time: Input files Tool Output files -------------------------------------------- */Makefile.in \ configure / */Makefile config.in | -------------> | config.h gmp-h.in | | config.m4 mp-h.in / | gmp.h | mp.h \ fat.h (fat binary build only) When configured with --enable-maintainer-mode the Makefiles include rules to re-run the necessary tools if the input files are changed. This can end up running a lot more things than are really necessary. If a build tree is in too much of a mess for those rules to work properly then a bootstrap can be done from the source directory with aclocal autoconf automake autoheader The autom4te.cache directory is created by autoconf to save some work in subsequent automake or autoheader runs. It's recreated automatically if removed, it doesn't get distributed. ** C++ configuration It's intended that the contents of libgmp.la won't vary according to whether --enable-cxx is selected. This means that if C++ shared libraries don't work properly then a shared+static with --disable-cxx can be done for the C parts, then a static-only with --enable-cxx to get libgmpxx. libgmpxx.la uses some internals from libgmp.la, in order to share code between C and C++. It's intended that libgmpxx can only be expected to work with libgmp from the same version of GMP. If some of the shared internals change their interface, then it's proposed to rename them, for instance __gmp_doprint2 or the like, so as to provoke link errors rather than mysterious failures from a mismatch. * Development setups ** General --disable-shared will make builds go much faster, though of course shared or shared+static should be tested too. --enable-mpbsd grabs various bits of mpz, which might need to be adjusted if things in those routines are changed. Building mpbsd all the time doesn't cost much. --prefix to a dummy directory followed by "make install" will show what's installed. "make check" acts on the libgmp just built, and will ignore any other /usr/lib/libgmp, or at least it should do. Libtool does various hairy things to ensure it hits the just-built library. ** Long long limb testing On systems where gcc supports long long, but a limb is normally just a long, the following can be used to force long long for testing purposes. It will probably run quite slowly. ./configure --host=none ABI=longlong ** Function argument conversions When using gcc, configuring with something like ./configure CFLAGS="-g -Wall -Wconversion -Wno-sign-compare" can show where function parameters are being converted due to having function prototypes available, which won't happen in a K&R compiler. Doing this in combination with the long long limb setups above is good. Conversions between int and long aren't warned about by gcc when they're the same size, which is unfortunate because casts should be used in such cases, for the benefit of K&R compilers with int!=long and where the difference matters in function calls. ** K&R support Function definitions must be in the GNU stylized form to work. See the ansi2knr.1 man page (included in the GMP sources). __GMP_PROTO is used for function prototypes, other ANSI / K&R differences are conditionalized in various places. Proper testing of the K&R support requires a compiler which gives an error for ANSI-isms. Configuring with --host=none is a good idea, to test all the generic C code. When using an ANSI compiler, the ansi2knr setups can be partially tested with ./configure am_cv_prog_cc_stdc=no ac_cv_prog_cc_stdc=no This will test the use of $U and the like in the makefiles, but not much else. Forcing the cache variables can be used with a compiler like HP C which is K&R by default but to which configure normally adds ANSI mode flags. This then should be a good full K&R test. * Other Notes ** Compatibility compat.c is the home of functions retained for binary compatibility, but now done by other means (like a macro). struct __mpz_struct etc - this must be retained for C++ compatibility. C++ applications defining functions taking mpz_t etc parameters will get this in the mangled name because C++ "sees though" the typedef mpz_t to the underlying struct. Incidentally, this probably means for C++ that our mp.h is not compatible with an original BSD mp.h, since we use struct __mpz_struct for MINT in ours. Maybe we could change to whatever the original did, but it seems unlikely anyone would be using C++ with mp.h. __gmpn - note that glibc defines some __mpn symbols, old versions of some mpn routines, which it uses for floating point printfs. Local variables: mode: outline fill-column: 70 End: /* eof doc/configuration */