spot/m4/lib-ld.m4

# lib-ld.m4 serial 9
dnl Copyright (C) 1996-2003, 2009-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

dnl Subroutines of libtool.m4,
dnl with replacements s/_*LT_PATH/AC_LIB_PROG/ and s/lt_/acl_/ to avoid
dnl collision with libtool.m4.

dnl From libtool-2.4. Sets the variable with_gnu_ld to yes or no.
AC_DEFUN([AC_LIB_PROG_LD_GNU],
[AC_CACHE_CHECK([if the linker ($LD) is GNU ld], [acl_cv_prog_gnu_ld],
[# I'd rather use --version here, but apparently some GNU lds only accept -v.
case `$LD -v 2>&1 </dev/null` in
*GNU* | *'with BFD'*)
  acl_cv_prog_gnu_ld=yes
  ;;
*)
  acl_cv_prog_gnu_ld=no
  ;;
esac])
with_gnu_ld=$acl_cv_prog_gnu_ld
])

dnl From libtool-2.4. Sets the variable LD.
AC_DEFUN([AC_LIB_PROG_LD],
[AC_REQUIRE([AC_PROG_CC])dnl
AC_REQUIRE([AC_CANONICAL_HOST])dnl

AC_ARG_WITH([gnu-ld],
    [AS_HELP_STRING([--with-gnu-ld],
        [assume the C compiler uses GNU ld [default=no]])],
    [test "$withval" = no || with_gnu_ld=yes],
    [with_gnu_ld=no])dnl

# Prepare PATH_SEPARATOR.
# The user is always right.
if test "${PATH_SEPARATOR+set}" != set; then
  # Determine PATH_SEPARATOR by trying to find /bin/sh in a PATH which
  # contains only /bin. Note that ksh looks also at the FPATH variable,
  # so we have to set that as well for the test.
  PATH_SEPARATOR=:
  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
    && { (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
           || PATH_SEPARATOR=';'
       }
fi

if test -n "$LD"; then
  AC_MSG_CHECKING([for ld])
elif test "$GCC" = yes; then
  AC_MSG_CHECKING([for ld used by $CC])
elif test "$with_gnu_ld" = yes; then
  AC_MSG_CHECKING([for GNU ld])
else
  AC_MSG_CHECKING([for non-GNU ld])
fi
if test -n "$LD"; then
  # Let the user override the test with a path.
  :
else
  AC_CACHE_VAL([acl_cv_path_LD],
  [
    acl_cv_path_LD= # Final result of this test
    ac_prog=ld # Program to search in $PATH
    if test "$GCC" = yes; then
      # Check if gcc -print-prog-name=ld gives a path.
      case $host in
        *-*-mingw*)
          # gcc leaves a trailing carriage return which upsets mingw
          acl_output=`($CC -print-prog-name=ld) 2>&5 | tr -d '\015'` ;;
        *)
          acl_output=`($CC -print-prog-name=ld) 2>&5` ;;
      esac
      case $acl_output in
        # Accept absolute paths.
        [[\\/]]* | ?:[[\\/]]*)
          re_direlt='/[[^/]][[^/]]*/\.\./'
          # Canonicalize the pathname of ld
          acl_output=`echo "$acl_output" | sed 's%\\\\%/%g'`
          while echo "$acl_output" | grep "$re_direlt" > /dev/null 2>&1; do
            acl_output=`echo $acl_output | sed "s%$re_direlt%/%"`
          done
          # Got the pathname. No search in PATH is needed.
          acl_cv_path_LD="$acl_output"
          ac_prog=
          ;;
        "")
          # If it fails, then pretend we aren't using GCC.
          ;;
        *)
          # If it is relative, then search for the first ld in PATH.
          with_gnu_ld=unknown
          ;;
      esac
    fi
    if test -n "$ac_prog"; then
      # Search for $ac_prog in $PATH.
      acl_save_ifs="$IFS"; IFS=$PATH_SEPARATOR
      for ac_dir in $PATH; do
        IFS="$acl_save_ifs"
        test -z "$ac_dir" && ac_dir=.
        if test -f "$ac_dir/$ac_prog" || test -f "$ac_dir/$ac_prog$ac_exeext"; then
          acl_cv_path_LD="$ac_dir/$ac_prog"
          # Check to see if the program is GNU ld.  I'd rather use --version,
          # but apparently some variants of GNU ld only accept -v.
          # Break only if it was the GNU/non-GNU ld that we prefer.
          case `"$acl_cv_path_LD" -v 2>&1 </dev/null` in
            *GNU* | *'with BFD'*)
              test "$with_gnu_ld" != no && break
              ;;
            *)
              test "$with_gnu_ld" != yes && break
              ;;
          esac
        fi
      done
      IFS="$acl_save_ifs"
    fi
    case $host in
      *-*-aix*)
        AC_COMPILE_IFELSE(
          [AC_LANG_SOURCE(
             [[#if defined __powerpc64__ || defined _ARCH_PPC64
                int ok;
               #else
                error fail
               #endif
             ]])],
          [# The compiler produces 64-bit code. Add option '-b64' so that the
           # linker groks 64-bit object files.
           case "$acl_cv_path_LD " in
             *" -b64 "*) ;;
             *) acl_cv_path_LD="$acl_cv_path_LD -b64" ;;
           esac
          ], [])
        ;;
      sparc64-*-netbsd*)
        AC_COMPILE_IFELSE(
          [AC_LANG_SOURCE(
             [[#if defined __sparcv9 || defined __arch64__
                int ok;
               #else
                error fail
               #endif
             ]])],
          [],
          [# The compiler produces 32-bit code. Add option '-m elf32_sparc'
           # so that the linker groks 32-bit object files.
           case "$acl_cv_path_LD " in
             *" -m elf32_sparc "*) ;;
             *) acl_cv_path_LD="$acl_cv_path_LD -m elf32_sparc" ;;
           esac
          ])
        ;;
    esac
  ])
  LD="$acl_cv_path_LD"
fi
if test -n "$LD"; then
  AC_MSG_RESULT([$LD])
else
  AC_MSG_RESULT([no])
  AC_MSG_ERROR([no acceptable ld found in \$PATH])
fi
AC_LIB_PROG_LD_GNU
])