README

On OS/2 the build goes the same way as on Unix, e.g.,

  sh Configure
  make gp
  make bench

With the current implementation of install(), one can load the functions from
the PARI library only if the GP executable is build for dynamic linking.

By default, the build will go to an AOUT-type executables (to simplify
the logic of Configure, and enable restricted binary compatibility with
DOS/Windows).  Unfortunately, AOUT-type DLLs are very restricted; thus
the build of dynamically linked target fails.

To build with OMF-type target

  cd Oos2-ix86
  make _O=.obj _A=.lib CC_FLAVOR="-Zomf -Zcrtdll -Zstack 8192" RLLIBS=-lreadline_import DLLD_IGNORE= AR=emxomfar bench

This build constructs a working DLL.  Both -Zomf and -Zcrtdll are crucial to
have a functioning DLL (see EMX documentation for details).  -Zstack 8192
forces the same C stack size as for AOUT build (and the same - 8M - as on many
Unices, so you get fewer surprises when things work on Unix, but core on OS/2
due only to shorter C stack).  (The standard Configure adds -Zsysv-signals
option; in fact, this option is not needed - as checked with v2.3.5.)

Use of the the readline-DLL (via the readline_import.lib library) is not only
a convenience, but also statically linked readline library are often broken;
sigh...

To use the gnuplot-engine DLL gnpltdrw.DLL, one can give Configure the option
--graphic=gnuplot-dynamic,gnpltdrw (requires linking with -Zcrtdll for graphics
to work).  Add -DOLD_SET_FEEDBACK_RECTANGLE gcc option if gnpltdrw.DLL supports
mousing, but is an old build, so it won't report this capability.

Thus the build process may look like this:

  sh Configure --graphic=gnuplot-dynamic,gnpltdrw
  make gp
  cd Oos2-ix86
  make _O=.obj _A=.lib CC_FLAVOR="-Zomf -Zcrtdll -Zstack 8192 -DUSE_SET_FEEDBACK_RECTANGLE" RLLIBS=-lreadline_import DLLD_IGNORE= AR=emxomfar bench
  cd ..

The statically build PARI library is in a file named similar to libpari-2_2.a,
the library for linking with the PARI DLL is named as pari-2_2.a (or
pari-2_2.lib).

As a debugging tool, the constructed DLL reports its build options via the
standard OS/2 way:

  bldlevel FULL_NAME_OF_THE_DLL