ExternalLibs-GMP

© 2016,2022 John Abbott, Anna M. Bigatti
GNU Free Documentation License, Version 1.2

CoCoALib Documentation Index

User documentation

GMP is an essential external library for CoCoALib: a sufficiently recent version of GMP (5.1.0 or later) must be present to permit compilation of CoCoALib. The CoCoALib classes BigInt and BigRat are simply wrappers for the underlying GMP types.

At the moment CoCoALib does not require the C++ interface to GMP, however if you wish to combine CoCoALib with the external library Normaliz then the C++ interface to GMP must also be present.

Examples

Installing the GMP library

It is common for Linux computers to have the GMP library already installed; the CoCoALib configure script will check for this, and will give an error message if it cannot be found.

In the unlikely event that GMP was not found by the CoCoALib configure script, we recommend using your computer's package manager to install a package having a name something like libgmp3-dev (or libgmpxx-devel or libgmp-devel). You should pick the version "for developers" as that is what CoCoALib needs.

Download and compile GMP

If you cannot install the GMP library using your package manager, you can try compiling it yourself! If you have little or no experience compiling software, ask someone who has experience to help you. It is not hard, but experience helps a lot!

To build the GMP library yourself, you must first download the sources from

**GMP** website

Note that CoCoALib expects GMP release 5.1.0 or later.

You must then decide whether to make a "personal" installation or a "system-wide" installation. To make a system-wide installation your account must have "administrator privileges"; in case of doubt, make a personal installation. 

  ## Commands for a ***system-wide*** installation
  tar xzf gmp-6.2.1.tar.gz
  cd gmp-6.2.1
  ./configure  --enable-cxx
  make
  sudo make install
  ## Maybe run the ldconfig command to register the shared library.
  ## You can now delete gmp-6.2.1.tar.gz and the directory gmp-6.2.1

To make a personal installation you must decide where GMP should be installed. We suggest something like $HOME/MySoftware (if you choose somewhere else, change the lines below accordingly). 

  ## Commands for a ***personal*** installation
  mkdir "$HOME/MySoftware"
  ./configure  --enable-cxx  --disable-shared  --prefix="$HOME/MySoftware"
  make
  make install
  ## You can now delete gmp-6.2.1.tar.gz and the directory gmp-6.2.1

Telling CoCoALib where GMP is

If you compiled GMP and did a system-wide installation then the CoCoALib configure script should find it automatically.

If you compiled GMP and made a personal installation then you must tell the CoCoALib configure script where to find GMP by using the option --with-libgmp. Here is an example: 

  cd CoCoALib-0.99  # go into the CoCoALib directory
  ./configure  --with-libgmp="$HOME/MySoftware/lib/libgmp.a"

FOOTNOTE System-wide installation on a GNU/Linux computer is possible only if your user account has the relevant permissions. You can check whether your account has permission by running sudo -v. This will ask for your password, and give an error if your account does not have permission.

Maintainer documentation

A future version of CoCoALib may use the C++ interface to GMP, but that it not imminent.

Bugs, shortcomings and other ideas

Strictly the parts of CoCoALib which compute with small finite fields do not need the GMP library; nevertheless we chose not to permit compilation without GMP.

I found the following website useful: 

  http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html

Main changes

2022

2016