Proper Procedure for installing GMP on Windows/MinGW/msys/Eclipse CDT

[Clay Codner]

All,

Here is a description of what I did to get GMP running under the Eclipse
CDT with Mingw and msys. Special thanks to Gabriel Risterucci for his help
and patience.

Here is the correct procedure for setting up the current (as of 7/2/13) GNU
bignum libraries with Eclipse CDT, MinGW, and msys for C++. To get through
this, you should have used Unix or Linux before, as well as Windows, and
you should have a vague recollection of programming and compiling programs.
This is the culmination of over a week of research and hardcore
frustration, so if I messed something up note it politely or I will blow
you up with the power of my mind!

1) I assume you have already downloaded and installed Eclipse and MinGW and
have installed msys into MinGW. You must install MinGW before msys!

2) Download the tarball for the GMP libraries from gmplib.org to
${gmp_download}. I downloaded the gmp-5.1.2.tar.xz because I have never
used lzip and didn't know if it was available in msys.

3) Open up an msys window (essentially a bash shell). cd ${gmp_buid} and
tar -Jxvf ${gmp_download}/gmp-x.x.x.tar.xz

Those tar options are different from what you may find elsewhere on the
web! -Jxvf is right for xz (and I think lzip), but for gzip you use -xzvf.

4) cd gmp-x.x.x and run ./config.guess. Write down the output. You will
need it next.

5) Run ./configure --prefix=${gmp_build} --build= --enable-cxx --with-gnu-ld

Apparently if you don't explicitly tell GMP to build for your platform it
builds everything, which is bad. The cxx option builds the C++ libraries
and --with-gnu-ld allows it to work with ld. Pretty straightforward.

6) make

7) make install

EX: suppose you installed to C:/gmp. You should have gmp/include/gmp.h and
gmpxx.h. You should also have gmp/lib/libgmp.a, libgmp.la, libgmpxx.a,
libgmpxx.la. You should also have a share directory with stuff in it.

8) Set up eclipse:

   - Go to project --> properties
   - Under C/C++ build --> Environment edit the PATH variable and add
   ${gmp_build}/include;${gmp_build}/lib
   - Under C/C++ build --> settings --> tool settings --> GCC Assembler -->
   general add ${gmp_build}/include as an include path.
   - Same place but --> GCC C++ compiler --> Includes add
   ${gmp_build}/include as an include path.
   - Same place --> GCC C++ compiler --> Miscellaneous add -lgmp -lgmpxx to
   the END of the line. THE END OF THE LINE!
   - Same place --> GCC C compiler Add the same include paths and
   miscellaneous options as before.
   - Same place --> MinGW C++ linker --> Libraries Add to the "Libraries
   (-l)" both *gmp* and *gmpxx* IN THAT ORDER! Now add ${gmp_build}/lib to
   "LIbrary Search Path (-L)"
   - Under C/C++ General --> Paths & Symbols --> Incudes Tab check that you
   have ${gmp_build}/include in your include directories for Assembly, C, and
   C++. If they aren't there you may have messed up an earlier step. They
   should be auto populated by Eclipse.
   - Same place --> Libraries Tab check that you have *gmp* and *gmpxx* IN
   THAT ORDER. It should already be populated.
   - Same Place --> Library Paths Tab Check for ${gmp_build}/lib which
   should already be there.
   - Hit "Apply" and make sure you rebuild the index or the changes won't
   take. Hit OK to close out.

9) Run this short program to verify your setup:

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <gmp.h>
#include <gmpxx.h>

using namespace std;

int main ()
{
    mpz_t p;
mpz_init_set_ui (p,3);

return 0;
}

Your compile commands should look similar to this:

g++ "-IC:\gmp\include" -O0 -g3 -Wall -c -fmessage-length=0 -lgmp -lgmpxx -o
main.o "..\main.cpp" g++ "-LC:\gmp\lib" -o GMPDebug.exe main.o -lgmp -lgmpxx

Notes:

1) The order of the options is important. I don't know all of the whys, but
if the second command line (which links the program) has the -lgmp -lgmpxx
flags before the -o option, the linking will fail miserably.

2) The -l flag is a tricky one. It actually says "Go look in -L for
liblibrary.a". In this case "Go look in C:\gmp\lib for libgmp.a and
libgmpxx.a".

3) I have heard of bugs involving cout and the 64 bit version of eclipse,
so I am using the 32 bit version, where I am seeing the same bug. :-)