# lib-prefix.m4 serial 17

dnl Copyright (C) 2001-2005, 2008-2020 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 From Bruno Haible.

dnl AC_LIB_PREFIX adds to the CPPFLAGS and LDFLAGS the flags that are needed

dnl to access previously installed libraries. The basic assumption is that

dnl a user will want packages to use other packages he previously installed

dnl with the same --prefix option.

dnl This macro is not needed if only AC_LIB_LINKFLAGS is used to locate

dnl libraries, but is otherwise very convenient.

AC_DEFUN([AC_LIB_PREFIX],

[

  AC_BEFORE([$0], [AC_LIB_LINKFLAGS])

  AC_REQUIRE([AC_PROG_CC])

  AC_REQUIRE([AC_CANONICAL_HOST])

  AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])

  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])

  dnl By default, look in $includedir and $libdir.

  use_additional=yes

  AC_LIB_WITH_FINAL_PREFIX([

    eval additional_includedir=\"$includedir\"

    eval additional_libdir=\"$libdir\"

  ])

  AC_ARG_WITH([lib-prefix],

[[  --with-lib-prefix[=DIR] search for libraries in DIR/include and DIR/lib

  --without-lib-prefix    don't search for libraries in includedir and libdir]],

[

    if test "X$withval" = "Xno"; then

      use_additional=no

    else

      if test "X$withval" = "X"; then

        AC_LIB_WITH_FINAL_PREFIX([

          eval additional_includedir=\"$includedir\"

          eval additional_libdir=\"$libdir\"

        ])

      else

        additional_includedir="$withval/include"

        additional_libdir="$withval/$acl_libdirstem"

      fi

    fi

])

  if test $use_additional = yes; then

    dnl Potentially add $additional_includedir to $CPPFLAGS.

    dnl But don't add it

    dnl   1. if it's the standard /usr/include,

    dnl   2. if it's already present in $CPPFLAGS,

    dnl   3. if it's /usr/local/include and we are using GCC on Linux,

    dnl   4. if it doesn't exist as a directory.

    if test "X$additional_includedir" != "X/usr/include"; then

      haveit=

      for x in $CPPFLAGS; do

        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])

        if test "X$x" = "X-I$additional_includedir"; then

          haveit=yes

          break

        fi

      done

      if test -z "$haveit"; then

        if test "X$additional_includedir" = "X/usr/local/include"; then

          if test -n "$GCC"; then

            case $host_os in

              linux* | gnu* | k*bsd*-gnu) haveit=yes;;

            esac

          fi

        fi

        if test -z "$haveit"; then

          if test -d "$additional_includedir"; then

            dnl Really add $additional_includedir to $CPPFLAGS.

            CPPFLAGS="${CPPFLAGS}${CPPFLAGS:+ }-I$additional_includedir"

          fi

        fi

      fi

    fi

    dnl Potentially add $additional_libdir to $LDFLAGS.

    dnl But don't add it

    dnl   1. if it's the standard /usr/lib,

    dnl   2. if it's already present in $LDFLAGS,

    dnl   3. if it's /usr/local/lib and we are using GCC on Linux,

    dnl   4. if it doesn't exist as a directory.

    if test "X$additional_libdir" != "X/usr/$acl_libdirstem"; then

      haveit=

      for x in $LDFLAGS; do

        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])

        if test "X$x" = "X-L$additional_libdir"; then

          haveit=yes

          break

        fi

      done

      if test -z "$haveit"; then

        if test "X$additional_libdir" = "X/usr/local/$acl_libdirstem"; then

          if test -n "$GCC"; then

            case $host_os in

              linux*) haveit=yes;;

            esac

          fi

        fi

        if test -z "$haveit"; then

          if test -d "$additional_libdir"; then

            dnl Really add $additional_libdir to $LDFLAGS.

            LDFLAGS="${LDFLAGS}${LDFLAGS:+ }-L$additional_libdir"

          fi

        fi

      fi

    fi

  fi

])

dnl AC_LIB_PREPARE_PREFIX creates variables acl_final_prefix,

dnl acl_final_exec_prefix, containing the values to which $prefix and

dnl $exec_prefix will expand at the end of the configure script.

AC_DEFUN([AC_LIB_PREPARE_PREFIX],

[

  dnl Unfortunately, prefix and exec_prefix get only finally determined

  dnl at the end of configure.

  if test "X$prefix" = "XNONE"; then

    acl_final_prefix="$ac_default_prefix"

  else

    acl_final_prefix="$prefix"

  fi

  if test "X$exec_prefix" = "XNONE"; then

    acl_final_exec_prefix='${prefix}'

  else

    acl_final_exec_prefix="$exec_prefix"

  fi

  acl_save_prefix="$prefix"

  prefix="$acl_final_prefix"

  eval acl_final_exec_prefix=\"$acl_final_exec_prefix\"

  prefix="$acl_save_prefix"

])

dnl AC_LIB_WITH_FINAL_PREFIX([statement]) evaluates statement, with the

dnl variables prefix and exec_prefix bound to the values they will have

dnl at the end of the configure script.

AC_DEFUN([AC_LIB_WITH_FINAL_PREFIX],

[

  acl_save_prefix="$prefix"

  prefix="$acl_final_prefix"

  acl_save_exec_prefix="$exec_prefix"

  exec_prefix="$acl_final_exec_prefix"

  $1

  exec_prefix="$acl_save_exec_prefix"

  prefix="$acl_save_prefix"

])

dnl AC_LIB_PREPARE_MULTILIB creates

dnl - a function acl_is_expected_elfclass, that tests whether standard input

dn;   has a 32-bit or 64-bit ELF header, depending on the host CPU ABI,

dnl - 3 variables acl_libdirstem, acl_libdirstem2, acl_libdirstem3, containing

dnl   the basename of the libdir to try in turn, either "lib" or "lib64" or

dnl   "lib/64" or "lib32" or "lib/sparcv9" or "lib/amd64" or similar.

AC_DEFUN([AC_LIB_PREPARE_MULTILIB],

[

  dnl There is no formal standard regarding lib, lib32, and lib64.

  dnl On most glibc systems, the current practice is that on a system supporting

  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under

  dnl $prefix/lib64 and 32-bit libraries go under $prefix/lib. However, on

  dnl Arch Linux based distributions, it's the opposite: 32-bit libraries go

  dnl under $prefix/lib32 and 64-bit libraries go under $prefix/lib.

  dnl We determine the compiler's default mode by looking at the compiler's

  dnl library search path. If at least one of its elements ends in /lib64 or

  dnl points to a directory whose absolute pathname ends in /lib64, we use that

  dnl for 64-bit ABIs. Similarly for 32-bit ABIs. Otherwise we use the default,

  dnl namely "lib".

  dnl On Solaris systems, the current practice is that on a system supporting

  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under

  dnl $prefix/lib/64 (which is a symlink to either $prefix/lib/sparcv9 or

  dnl $prefix/lib/amd64) and 32-bit libraries go under $prefix/lib.

  AC_REQUIRE([AC_CANONICAL_HOST])

  AC_REQUIRE([gl_HOST_CPU_C_ABI_32BIT])

  AC_CACHE_CHECK([for ELF binary format], [gl_cv_elf],

    [AC_EGREP_CPP([Extensible Linking Format],

       [#ifdef __ELF__

        Extensible Linking Format

        #endif

       ],

       [gl_cv_elf=yes],

       [gl_cv_elf=no])

     ])

  if test $gl_cv_elf; then

    # Extract the ELF class of a file (5th byte) in decimal.

    # Cf. https://en.wikipedia.org/wiki/Executable_and_Linkable_Format#File_header

    if od -A x < /dev/null >/dev/null 2>/dev/null; then

      # Use POSIX od.

      func_elfclass ()

      {

        od -A n -t d1 -j 4 -N 1

      }

    else

      # Use BSD hexdump.

      func_elfclass ()

      {

        dd bs=1 count=1 skip=4 2>/dev/null | hexdump -e '1/1 "%3d "'

        echo

      }

    fi

changequote(,)dnl

    case $HOST_CPU_C_ABI_32BIT in

      yes)

        # 32-bit ABI.

        acl_is_expected_elfclass ()

        {

          test "`func_elfclass | sed -e 's/[ 	]//g'`" = 1

        }

        ;;

      no)

        # 64-bit ABI.

        acl_is_expected_elfclass ()

        {

          test "`func_elfclass | sed -e 's/[ 	]//g'`" = 2

        }

        ;;

      *)

        # Unknown.

        acl_is_expected_elfclass ()

        {

          :

        }

        ;;

    esac

changequote([,])dnl

  else

    acl_is_expected_elfclass ()

    {

      :

    }

  fi

  dnl Allow the user to override the result by setting acl_cv_libdirstems.

  AC_CACHE_CHECK([for the common suffixes of directories in the library search path],

    [acl_cv_libdirstems],

    [dnl Try 'lib' first, because that's the default for libdir in GNU, see

     dnl <https://www.gnu.org/prep/standards/html_node/Directory-Variables.html>.

     acl_libdirstem=lib

     acl_libdirstem2=

     acl_libdirstem3=

     case "$host_os" in

       solaris*)

         dnl See Solaris 10 Software Developer Collection > Solaris 64-bit Developer's Guide > The Development Environment

         dnl <https://docs.oracle.com/cd/E19253-01/816-5138/dev-env/index.html>.

         dnl "Portable Makefiles should refer to any library directories using the 64 symbolic link."

         dnl But we want to recognize the sparcv9 or amd64 subdirectory also if the

         dnl symlink is missing, so we set acl_libdirstem2 too.

         if test $HOST_CPU_C_ABI_32BIT = no; then

           acl_libdirstem2=lib/64

           case "$host_cpu" in

             sparc*)        acl_libdirstem3=lib/sparcv9 ;;

             i*86 | x86_64) acl_libdirstem3=lib/amd64 ;;

           esac

         fi

         ;;

       *)

         dnl If $CC generates code for a 32-bit ABI, the libraries are

         dnl surely under $prefix/lib or $prefix/lib32, not $prefix/lib64.

         dnl Similarly, if $CC generates code for a 64-bit ABI, the libraries

         dnl are surely under $prefix/lib or $prefix/lib64, not $prefix/lib32.

         dnl Find the compiler's search path. However, non-system compilers

         dnl sometimes have odd library search paths. But we can't simply invoke

         dnl '/usr/bin/gcc -print-search-dirs' because that would not take into

         dnl account the -m32/-m31 or -m64 options from the $CC or $CFLAGS.

         searchpath=`(LC_ALL=C $CC $CPPFLAGS $CFLAGS -print-search-dirs) 2>/dev/null \

                     | sed -n -e 's,^libraries: ,,p' | sed -e 's,^=,,'`

         if test $HOST_CPU_C_ABI_32BIT != no; then

           # 32-bit or unknown ABI.

           if test -d /usr/lib32; then

             acl_libdirstem2=lib32

           fi

         fi

         if test $HOST_CPU_C_ABI_32BIT != yes; then

           # 64-bit or unknown ABI.

           if test -d /usr/lib64; then

             acl_libdirstem3=lib64

           fi

         fi

         if test -n "$searchpath"; then

           acl_save_IFS="${IFS= 	}"; IFS=":"

           for searchdir in $searchpath; do

             if test -d "$searchdir"; then

               case "$searchdir" in

                 */lib32/ | */lib32 ) acl_libdirstem2=lib32 ;;

                 */lib64/ | */lib64 ) acl_libdirstem3=lib64 ;;

                 */../ | */.. )

                   # Better ignore directories of this form. They are misleading.

                   ;;

                 *) searchdir=`cd "$searchdir" && pwd`

                    case "$searchdir" in

                      */lib32 ) acl_libdirstem2=lib32 ;;

                      */lib64 ) acl_libdirstem3=lib64 ;;

                    esac ;;

               esac

             fi

           done

           IFS="$acl_save_IFS"

           if test $HOST_CPU_C_ABI_32BIT = yes; then

             # 32-bit ABI.

             acl_libdirstem3=

           fi

           if test $HOST_CPU_C_ABI_32BIT = no; then

             # 64-bit ABI.

             acl_libdirstem2=

           fi

         fi

         ;;

     esac

     test -n "$acl_libdirstem2" || acl_libdirstem2="$acl_libdirstem"

     test -n "$acl_libdirstem3" || acl_libdirstem3="$acl_libdirstem"

     acl_cv_libdirstems="$acl_libdirstem,$acl_libdirstem2,$acl_libdirstem3"

    ])

  dnl Decompose acl_cv_libdirstems into acl_libdirstem, acl_libdirstem2, and

  dnl acl_libdirstem3.

changequote(,)dnl

  acl_libdirstem=`echo "$acl_cv_libdirstems" | sed -e 's/,.*//'`

  acl_libdirstem2=`echo "$acl_cv_libdirstems" | sed -e 's/^[^,]*,//' -e 's/,.*//'`

  acl_libdirstem3=`echo "$acl_cv_libdirstems" | sed -e 's/^[^,]*,[^,]*,//' -e 's/,.*//'`

changequote([,])dnl

])