third_party_mesa3d/acinclude.m4
Dan Nicholson d368eed9c7 autoconf: Attempt to figure out the PIC flags for the platform
This commit adds an autoconf macro, MESA_PIC_FLAGS, which sets the
PIC flags according to platform and static/shared setting. The platform
specifics are taken straight from libtool.m4 and stripped down to just
the flags and platforms we cover in Mesa. This should hopefully make it
possible to use autoconf on non-GCC platforms.

The macro is added external to configure.ac in acinclude.m4 since it's
pretty bloated.

Note to BSDers: Previously, x86 defaulted to non-PIC on FreeBSD. I
didn't carry that preference into this macro. Instead, you can just use
--disable-pic where desired.
2008-05-09 07:05:16 -07:00

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# A few convenience macros for Mesa, mostly to keep all the platform
# specifics out of configure.ac.
# MESA_PIC_FLAGS()
#
# Find out whether to build PIC code using the option --enable-pic and
# the configure enable_static/enable_shared settings. If PIC is needed,
# figure out the necessary flags for the platform and compiler.
#
# The platform checks have been shamelessly taken from libtool and
# stripped down to just what's needed for Mesa. See _LT_COMPILER_PIC in
# /usr/share/aclocal/libtool.m4 or
# http://git.savannah.gnu.org/gitweb/?p=libtool.git;a=blob;f=libltdl/m4/libtool.m4;hb=HEAD
#
AC_DEFUN([MESA_PIC_FLAGS],
[AC_REQUIRE([AC_PROG_CC])dnl
AC_ARG_VAR([PIC_FLAGS], [compiler flags for PIC code])
AC_ARG_ENABLE([pic],
[AS_HELP_STRING([--disable-pic],
[compile PIC objects @<:@default=enabled for shared builds
on supported platforms@:>@])],
[enable_pic="$enableval"
test "x$enable_pic" = x && enable_pic=auto],
[enable_pic=auto])
# disable PIC by default for static builds
if test "$enable_pic" = auto && test "$enable_static" = yes; then
enable_pic=no
fi
# if PIC hasn't been explicitly disabled, try to figure out the flags
if test "$enable_pic" != no; then
AC_MSG_CHECKING([for $CC option to produce PIC])
# allow the user's flags to override
if test "x$PIC_FLAGS" = x; then
# see if we're using GCC
if test "x$GCC" = xyes; then
case "$host_os" in
aix*|beos*|cygwin*|irix5*|irix6*|osf3*|osf4*|osf5*)
# PIC is the default for these OSes.
;;
mingw*|os2*|pw32*)
# This hack is so that the source file can tell whether
# it is being built for inclusion in a dll (and should
# export symbols for example).
PIC_FLAGS="-DDLL_EXPORT"
;;
darwin*|rhapsody*)
# PIC is the default on this platform
# Common symbols not allowed in MH_DYLIB files
PIC_FLAGS="-fno-common"
;;
hpux*)
# PIC is the default for IA64 HP-UX and 64-bit HP-UX,
# but not for PA HP-UX.
case $host_cpu in
hppa*64*|ia64*)
;;
*)
PIC_FLAGS="-fPIC"
;;
esac
;;
*)
# Everyone else on GCC uses -fPIC
PIC_FLAGS="-fPIC"
;;
esac
else # !GCC
case "$host_os" in
hpux9*|hpux10*|hpux11*)
# PIC is the default for IA64 HP-UX and 64-bit HP-UX,
# but not for PA HP-UX.
case "$host_cpu" in
hppa*64*|ia64*)
# +Z the default
;;
*)
PIC_FLAGS="+Z"
;;
esac
;;
linux*|k*bsd*-gnu)
case `basename "$CC"` in
icc*|ecc*|ifort*)
PIC_FLAGS="-KPIC"
;;
pgcc*|pgf77*|pgf90*|pgf95*)
# Portland Group compilers (*not* the Pentium gcc
# compiler, which looks to be a dead project)
PIC_FLAGS="-fpic"
;;
ccc*)
# All Alpha code is PIC.
;;
xl*)
# IBM XL C 8.0/Fortran 10.1 on PPC
PIC_FLAGS="-qpic"
;;
*)
case `$CC -V 2>&1 | sed 5q` in
*Sun\ C*|*Sun\ F*)
# Sun C 5.9 or Sun Fortran
PIC_FLAGS="-KPIC"
;;
esac
esac
;;
solaris*)
PIC_FLAGS="-KPIC"
;;
sunos4*)
PIC_FLAGS="-PIC"
;;
esac
fi # GCC
fi # PIC_FLAGS
AC_MSG_RESULT([$PIC_FLAGS])
fi
AC_SUBST([PIC_FLAGS])
])# MESA_PIC_FLAGS