source4/build/m4/check_ld.m4

   1 dnl SMB Build Environment LD Checks
   2 dnl -------------------------------------------------------
   3 dnl  Copyright (C) Stefan (metze) Metzmacher 2004
   4 dnl  Copyright (C) Jelmer Vernooij 2006
   5 dnl  Released under the GNU GPL
   6 dnl -------------------------------------------------------
   7 dnl
   8
   9 AC_PATH_PROG(PROG_LD,ld)
  10 LD=${PROG_LD}
  11 AC_PROG_LD_GNU
  12 LD=""
  13
  14 AC_SUBST(BLDSHARED)
  15 AC_SUBST(LD)
  16 AC_SUBST(SYS_LDFLAGS)
  17 AC_SUBST(LDFLAGS)
  18
  19 # Assume non-shared by default and override below
  20 # these are the defaults, good for lots of systems
  21 BLDSHARED="false"
  22 LD="${CC}"
  23 PICFLAG=""
  24
  25 # allow for --with-hostld=gcc
  26 AC_ARG_WITH(hostld,[  --with-hostld=linker    choose host linker],
  27 [HOSTLD=$withval],
  28 [HOSTLD=$HOSTCC])
  29
  30 AC_MSG_CHECKING([whether to try to build shared libraries on $host_os])
  31
  32 # and these are for particular systems
  33 case "$host_os" in
  34         *linux*)
  35                 BLDSHARED="true"
  36                 SYS_LDFLAGS="-Wl,--export-dynamic"
  37                 ;;
  38         *solaris*)
  39                 BLDSHARED="true"
  40                 if test "${GCC}" = "yes"; then
  41                         if test "${ac_cv_prog_gnu_ld}" = "yes"; then
  42                                 SYS_LDFLAGS="-Wl,-E"
  43                         fi
  44                 fi
  45                 ;;
  46         *sunos*)
  47                 BLDSHARED="true"
  48                 ;;
  49         *netbsd* | *freebsd* | *dragonfly* )
  50                 BLDSHARED="true"
  51                 SYS_LDFLAGS="-Wl,--export-dynamic"
  52                 ;;
  53         *openbsd*)
  54                 BLDSHARED="true"
  55                 SYS_LDFLAGS="-Wl,-Bdynamic"
  56                 ;;
  57         *irix*)
  58                 BLDSHARED="true"
  59                 ;;
  60         *aix*)
  61                 BLDSHARED="true"
  62                 SYS_LDFLAGS="-Wl,-brtl,-bexpall,-bbigtoc"
  63                 ;;
  64         *hpux*)
  65                 # Use special PIC flags for the native HP-UX compiler.
  66                 BLDSHARED="true" # I hope this is correct
  67                 if test "$host_cpu" = "ia64"; then
  68                         SYS_LDFLAGS="-Wl,-E,+b/usr/local/lib/hpux32:/usr/lib/hpux32"
  69                 else
  70                         SYS_LDFLAGS="-Wl,-E,+b/usr/local/lib:/usr/lib"
  71                 fi
  72                 ;;
  73         *osf*)
  74                 BLDSHARED="true"
  75                 ;;
  76         *unixware*)
  77                 BLDSHARED="true"
  78                 ;;
  79         *darwin*)
  80                 BLDSHARED="true"
  81                 ;;
  82 esac
  83
  84 AC_MSG_RESULT($BLDSHARED)
  85
  86 AC_MSG_CHECKING([LD])
  87 AC_MSG_RESULT([$LD])
  88 AC_MSG_CHECKING([LDFLAGS])
  89 AC_MSG_RESULT([$LDFLAGS])
  90 AC_MSG_CHECKING([SYS_LDFLAGS])
  91 AC_MSG_RESULT([$SYS_LDFLAGS])
  92
  93 AC_SUBST(HOSTLD)
  94
  95 AC_LIBREPLACE_STLD
  96 AC_LIBREPLACE_STLD_FLAGS
  97
  98 AC_MSG_CHECKING([STLD])
  99 AC_MSG_RESULT([$STLD])
 100 AC_MSG_CHECKING([STLD_FLAGS])
 101 AC_MSG_RESULT([$STLD_FLAGS])
 102
 103 AC_LD_PICFLAG
 104 AC_LD_EXPORT_DYNAMIC
 105 AC_LD_SHLIBEXT
 106 AC_LD_SONAMEFLAG
 107 AC_LIBREPLACE_SHLD
 108 AC_LIBREPLACE_SHLD_FLAGS
 109 AC_LIBREPLACE_MDLD
 110 AC_LIBREPLACE_MDLD_FLAGS
 111 AC_LIBREPLACE_RUNTIME_LIB_PATH_VAR
 112
 113 #######################################################
 114 # test whether building a shared library actually works
 115 if test $BLDSHARED = true; then
 116
 117         AC_MSG_CHECKING([SHLD])
 118         AC_MSG_RESULT([$SHLD])
 119         AC_MSG_CHECKING([SHLD_FLAGS])
 120         AC_MSG_RESULT([$SHLD_FLAGS])
 121
 122         AC_MSG_CHECKING([MDLD])
 123         AC_MSG_RESULT([$MDLD])
 124         AC_MSG_CHECKING([MDLD_FLAGS])
 125         AC_MSG_RESULT([$MDLD_FLAGS])
 126
 127         AC_MSG_CHECKING([SHLIBEXT])
 128         AC_MSG_RESULT([$SHLIBEXT])
 129         AC_MSG_CHECKING([SONAMEFLAG])
 130         AC_MSG_RESULT([$SONAMEFLAG])
 131
 132         AC_MSG_CHECKING([PICFLAG])
 133         AC_MSG_RESULT([$PICFLAG])
 134
 135         AC_CACHE_CHECK([whether building shared libraries actually works],
 136                        [ac_cv_shlib_works],[
 137                         ac_cv_shlib_works=no
 138                         # try building a trivial shared library
 139                         # TODO: also test SONAMEFLAG
 140                         ${CC} ${CFLAGS} ${PICFLAG} -c ${srcdir-.}/../tests/shlib.c -o shlib.o &&
 141                                 ${SHLD} ${SHLD_FLAGS} -o shlib.${SHLIBEXT} shlib.o &&
 142                                 ac_cv_shlib_works=yes
 143                         rm -f shlib.${SHLIBEXT} shlib.o
 144         ])
 145         AC_CACHE_CHECK([whether building shared modules actually works],
 146                        [ac_cv_shmod_works],[
 147                         ac_cv_shmod_works=no
 148                         # try building a trivial shared library
 149                         ${CC} ${CFLAGS} ${PICFLAG} -c ${srcdir-.}/../tests/shlib.c -o shlib.o &&
 150                                 ${MDLD} ${MDLD_FLAGS} -o shlib.${SHLIBEXT} shlib.o &&
 151                                 ac_cv_shmod_works=yes
 152                         rm -f shlib.${SHLIBEXT} shlib.o
 153         ])
 154         if test $ac_cv_shlib_works = no; then
 155                 AC_MSG_ERROR(unable to build shared libraries)
 156         fi
 157         if test $ac_cv_shmod_works = no; then
 158                 AC_MSG_ERROR(unable to build shared modules)
 159         fi
 160 fi
 161
 162 AC_DEFINE_UNQUOTED(SHLIBEXT, "$SHLIBEXT", [Shared library extension])
 163
 164 AC_MSG_CHECKING([if we can link using the selected flags])
 165 AC_TRY_RUN([#include "${srcdir-.}/../tests/trivial.c"],
 166             AC_MSG_RESULT(yes),
 167             AC_MSG_ERROR([we cannot link with the selected cc and ld flags. Aborting configure]),
 168             AC_MSG_WARN([cannot run when cross-compiling]))
 169
 170
 171 USESHARED=false
 172 AC_SUBST(USESHARED)
 173
 174 AC_ARG_ENABLE(dso,
 175 [  --enable-dso                   Enable using shared libraries internally (experimental)],
 176 [],[enable_dso=no])
 177
 178 if test x"$enable_dso" = x"yes" -a x"$BLDSHARED" != x"true"; then
 179         AC_MSG_ERROR([--enable-dso: no support for shared libraries])
 180 fi
 181
 182 if test x"$enable_dso" != x"no"; then
 183         USESHARED=$BLDSHARED
 184 fi
 185
 186 AC_MSG_CHECKING([if binaries will use shared libraries])
 187 AC_MSG_RESULT([$USESHARED])