Split stlkos into library + executable REPL, and we'd have embedded STklos

[jpellegrini]

Hi @egallesio !

I was trying to do what I mentioned in the subject. stklos.c is very small, and a simple C program embedding STklos couldbe even smaller, since it wouldn't need to process command line options.

But I found a problem:
Currnetly it seems that the STklos build process doesn't use libtool. If I change src/Makefile.am to build libstklos and add LT_INIT to configure.ac, the configure script stops detecting the OS (???):

SUMMARY
*******
               System:  -
              OS nick:  _
              OS type: 
      Install prefix :  /usr/local
           C compiler:  gcc
    Compilation flags:  -g -O2
               Loader:  /usr/bin/ld -m elf_x86_64
       Thread support:  pthreads
     Case sensitivity:  true (by default)
Control fx parameters:  yes
System libraries used:  libffi libpcre libgmp libgc
   Compiled libraries: 

And then (of course) compilation fails, because it depends on those variables.

I tried to understand how configure.ac detects the operating system, and I really don't get it: as far as I understand, the "OS" variable is not available, except on Windows (is that correct). But it is used in configure.ac:

BUILD_OS=$os-$version
BUILD_ARCH=`uname -m`
OS_NAME=$OS
case $OS in
   LINUX) ...

The only variables related to operating systems that I thought would come from autotools would be $host_os and $build_os, which people ten do recommend using as follows:

AC_CANONICAL_HOST

build_linux=no
build_windows=no
build_mac=no

case "${host_os}" in
    linux*)
        build_linux=yes
        ;;
    cygwin*|mingw*)
        build_windows=yes
        ;;
    darwin*)
        build_mac=yes
        ;;
    *)
        AC_MSG_ERROR(["$host_os is not supported"])
        ;;
esac

AM_CONDITIONAL([LINUX], [test "$build_linux" = "yes"])
AM_CONDITIONAL([WINDOWS], [test "$build_windows" = "yes"])
AM_CONDITIONAL([OSX], [test "$build_mac" = "yes"])

But I'm really no autotools expert.

How's the status of supported platforms today, and how can we make configure.ac better?
It would be really nice to have a libstklos separate from the binary.

[jpellegrini]

Ah, I see - utils/shlib-options sets those variables! I put LT_INIT after utils/shlib-options is used, and it seems to work. I'll keep working on this, maybe we'll have embedded STklos soon.

[jpellegrini]

@egallesio I got it working!

But there's one small problem: the new STklos would install include files that could conflict with others in the system, like

/usr/include/socket.h
/usr/include/extraconf.h

and we should probably offer some other header files from src to the user.

I think we should either:

• Put all needed definitions for embedded programming in stklos.h (but it may get too large), or
• Give some of those files different names

What do you think?

I'll make a PR so you can see what I've been doing.

[jpellegrini]

See PR #263