source: trunk/libs/newlib/src/config/picflag.m4 @ 523

# _GCC_PICFLAG(FLAG, DISPATCH)
# ----------------------------
# Store PIC flag corresponding to DISPATCH triplet in FLAG.
# Explit use of -fpic in CFLAGS corresponding to FLAG overrides default.
AC_DEFUN([_GCC_PICFLAG], [

case "${$2}" in
    # PIC is the default on some targets or must not be used.
    *-*-darwin*)
        # For darwin, common symbols are not allowed in MH_DYLIB files
        case "${CFLAGS}" in
          # If we are using a compiler supporting mdynamic-no-pic
          # and the option has been tested as safe to add, then cancel
          # it here, since the code generated is incompatible with shared
          # libs.
          *-mdynamic-no-pic*) $1='-fno-common -mno-dynamic-no-pic' ;;
          *) $1=-fno-common ;;
        esac
        ;;
    alpha*-dec-osf5*)
        # PIC is the default.
        ;;
    hppa*64*-*-hpux*)
        # PIC is the default for 64-bit PA HP-UX.
        ;;
    i[[34567]]86-*-cygwin* | x86_64-*-cygwin*)
        ;;
    i[[34567]]86-*-mingw* | x86_64-*-mingw*)
        ;;
    i[[34567]]86-*-nto-qnx*)
        # QNX uses GNU C++, but need to define -shared option too, otherwise
        # it will coredump.
        $1='-fPIC -shared'
        ;;
    i[[34567]]86-pc-msdosdjgpp*)
        # DJGPP does not support shared libraries at all.
        ;;
    ia64*-*-hpux*)
        # On IA64 HP-UX, PIC is the default but the pic flag
        # sets the default TLS model and affects inlining.
        $1=-fPIC
        ;;
    mips-sgi-irix6*)
        # PIC is the default.
        ;;
    rs6000-ibm-aix* | powerpc-ibm-aix*)
        # All AIX code is PIC.
        ;;

    # Some targets support both -fPIC and -fpic, but prefer the latter.
    # FIXME: Why?
    i[[34567]]86-*-* | x86_64-*-*)
        $1=-fpic
        ;;
    # FIXME: Override -fPIC default in libgcc only? 
    sh-*-linux* | sh[[2346lbe]]*-*-linux*)
        $1=-fpic
        ;;
    # FIXME: Simplify to sh*-*-netbsd*?
    sh-*-netbsdelf* | shl*-*-netbsdelf*)
        $1=-fpic
        ;;
    # Default to -fPIC unless specified otherwise.
    *)
        $1=-fPIC
        ;;
esac

# If the user explicitly uses -fpic/-fPIC, keep that.
case "${m4_bpatsubsts($1, PICFLAG, CFLAGS)}" in
    *-fpic*)
        $1=-fpic
        ;;
    *-fPIC*)
        $1=-fPIC
        ;;
esac
])

# GCC_PICFLAG
# -----------
# Store host PIC flag in PICFLAG.
AC_DEFUN([GCC_PICFLAG], [
  AC_REQUIRE([AC_CANONICAL_HOST])
  _GCC_PICFLAG([PICFLAG], [host])])

# GCC_PICFLAG_FOR_TARGET
# ----------------------
# Store target PIC flag in PICFLAG_FOR_TARGET.
AC_DEFUN([GCC_PICFLAG_FOR_TARGET], [
  AC_REQUIRE([AC_CANONICAL_TARGET])
  _GCC_PICFLAG([PICFLAG_FOR_TARGET], [target])])