Re: [Sablevm-developer] building out-of-the-box on non-Linux platform

[Patrick C. <er...@ps...>]

Also sprach Grzegorz B. Prokopski zu "17.01.2004 11:08" Anno Domini:
> W liście z sob, 17-01-2004, godz. 04:17, David Bélanger pisze: 
> 
>>Hi,
>>
>>I think it would be great if SableVM could be built out-of-the-box on
>>all platforms including the non-Linuxian FreeBSD and OS X.  It will
>>simplify my life as I want to build and test on these platforms.
>>Currently source code is not an issue, it is more a configure/Makefile
>>isssue.
>>
>>src/libsablevm/Makefile.am has some line like:
>>libsablevm_la_LIBADD = -lpthread -lm -lffi -lltdl -lrt
>>
>>FreeBSD does not like -lpthread.
>>OS X does not like -lrt.
>>
>>This is because functionnality is located elsewhere and there are
>>no such libXX.so file...  (Actually, on OS X, there is a single
>>libSystem that includes implementation of libc, libm, libpthread and
>>probably others.  libc etc. are only symlinks to libSystem.  But there
>>are no librt symlinks in the default installation)
>>
>>A long time ago, I had:
>>if REQ_LPTHREAD
>>REQ_LIBS = -lpthread -lm -lffi -lltdl -lrt
>>else
>>REQ_LIBS = -lc_r -lm -lffi -lltdl -lrt
>>endif
>>libsablevm_la_LIBADD = ${REQ_LIBS}
>>
>>where REQ_LPTHREAD was set in ./configure.ac.
>>
>>This was ok for FreeBSD but will become more complex with -lrt on/off.
>>Note: I tried first with simpler things but automake/conf tools didn't
>>like it.  There are some restriction of what the right hand side arg
>>of libsablevm_la_LIBADD can be for the autoconf/make tools, don't
>>remember which one.
> 
> 
> svn diff -r 1204:HEAD \
>  svn://svn.sablevm.org/developers/mlord/sandbox/sablevm-staging |less
> 
> will show you what was changed for cygwin port (not yet merged)
> It also didn't like -lrt (only Solaris requires it apparently)
> but it wasn't solved nicely.
> 
> But if we take a look at these parts:
> 
> +++ configure.ac        (revision 1385)
> +dnl defining macro (platform_win32) only for Cygwin or Mingw
> +AC_MSG_CHECKING([for some Win32 platform])
> +
> +case "$host" in
> +  *-*-mingw*|*-*-cygwin*)
> +    platform_win32=yes
> +    ;;
> +  *)
> +    platform_win32=no
> +    ;;
> +esac
> +AC_MSG_RESULT([$platform_win32])
> +AM_CONDITIONAL(PLATFORM_WIN32, test "$platform_win32" = "yes")
> +
> +++ src/libsablevm/Makefile.am  (revision 1385)
> +if PLATFORM_WIN32
> +no_undefined = -no-undefined
> +endif
> +
> [...]
> +libsablevm_la_LDFLAGS = -version-info @LIBRARY_VERSION@ $(no_undefined)
> 
> One could add detection of other platforms in configure.ac and
> accordignly add in makefiles ex. 
> +if PLATFORM_SOLARIS
> +lrt=-lrt
> +endif
> and so on...
> 
> But I don't think I like this stuff, first because it'd require us to
> create PLATOFORM_* defines for maaaany platforms, second - this config
> info (what to link with or not) looks like global stuff, so why would
> it reside in one Makefile.am and not in the other one(s)? We should
> save ourselves coding and do maximum of it in one place (configure),
> while minimizing changes in other places (Makefiles).
> 
> Ideally, I think we'd have in configure.ac sth. like:
> +AC_MSG_CHECKING([if we need -no-undefined])
> +
> +case "$host" in
> +  *-*-mingw*|*-*-cygwin*)
> +    no_undefined=-no-undefined
> +    AC_MSG_RESULT([yes])
> +    ;;
> +  *)
> +    AC_MSG_RESULT([no])
> +    ;;
> +esac
> 
> +AC_MSG_CHECKING([if we need -lrt])
> +
> +case "$host" in
> +  *solaris*)
> +    lrt=-lrt
> +    AC_MSG_RESULT([yes])
> +    ;;
> +  *)
> +    AC_MSG_RESULT([no])
> +    ;;
> +esac
> 
> +AC_MSG_CHECKING([if we need -lpthread])
> +
> +case "$host" in
> +  *freebsd*)
> +    AC_MSG_RESULT([no])
> +    ;;
> +  *)
> +    lpthread=-lpthread
> +    AC_MSG_RESULT([yes])
> +    ;;
> +esac
> 
> (system id strings, besides cygwin/mingw should probably be narowed)
> 
> and then use @no_undefined@, @lrt@ and @lpthread@ in Makefiles - where
> needed. They either would contain respective params or be empty.

That's exactly what you should do in configure! For that reason, there
are more macros provided by autoconf that only "AC_MSG_*". Your last
case for example could be simpliefied to a simple one-liner using
AC_CHECK_LIB! Have a look at the autoconf info pages for a complete
overview. A call of autoscan in your sources could also be helpful (have
a look at the generated configure.scan template). On Debian, there
exists a package named autobook with a quiet complete html documentation
about auto*. Last but not least, three pointers:

http://seul.org/docs/autotut/
http://www.amath.washington.edu/~lf/tutorials/autoconf/
http://nis-www.lanl.gov/~rosalia/mydocs/autoconf_tutorial_toc.html

Hope this help!

CU
-- 
Patrick Cernko | mailto:er...@er... | http://www.errror.de
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