build: detect the right `ar` tool

autotools/ar-lib

+#! /bin/sh
+# Wrapper for Microsoft lib.exe
+
+me=ar-lib
+scriptversion=2012-03-01.08; # UTC
+
+# Copyright (C) 2010-2014 Free Software Foundation, Inc.
+# Written by Peter Rosin <peda@lysator.liu.se>.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+
+# func_error message
+func_error ()
+{
+  echo "$me: $1" 1>&2
+  exit 1
+}
+
+file_conv=
+
+# func_file_conv build_file
+# Convert a $build file to $host form and store it in $file
+# Currently only supports Windows hosts.
+func_file_conv ()
+{
+  file=$1
+  case $file in
+    / | /[!/]*) # absolute file, and not a UNC file
+      if test -z "$file_conv"; then
+        # lazily determine how to convert abs files
+        case `uname -s` in
+          MINGW*)
+            file_conv=mingw
+            ;;
+          CYGWIN*)
+            file_conv=cygwin
+            ;;
+          *)
+            file_conv=wine
+            ;;
+        esac
+      fi
+      case $file_conv in
+        mingw)
+          file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
+          ;;
+        cygwin)
+          file=`cygpath -m "$file" || echo "$file"`
+          ;;
+        wine)
+          file=`winepath -w "$file" || echo "$file"`
+          ;;
+      esac
+      ;;
+  esac
+}
+
+# func_at_file at_file operation archive
+# Iterate over all members in AT_FILE performing OPERATION on ARCHIVE
+# for each of them.
+# When interpreting the content of the @FILE, do NOT use func_file_conv,
+# since the user would need to supply preconverted file names to
+# binutils ar, at least for MinGW.
+func_at_file ()
+{
+  operation=$2
+  archive=$3
+  at_file_contents=`cat "$1"`
+  eval set x "$at_file_contents"
+  shift
+
+  for member
+  do
+    $AR -NOLOGO $operation:"$member" "$archive" || exit $?
+  done
+}
+
+case $1 in
+  '')
+     func_error "no command.  Try '$0 --help' for more information."
+     ;;
+  -h | --h*)
+    cat <<EOF
+Usage: $me [--help] [--version] PROGRAM ACTION ARCHIVE [MEMBER...]
+
+Members may be specified in a file named with @FILE.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "$me, version $scriptversion"
+    exit $?
+    ;;
+esac
+
+if test $# -lt 3; then
+  func_error "you must specify a program, an action and an archive"
+fi
+
+AR=$1
+shift
+while :
+do
+  if test $# -lt 2; then
+    func_error "you must specify a program, an action and an archive"
+  fi
+  case $1 in
+    -lib | -LIB \
+    | -ltcg | -LTCG \
+    | -machine* | -MACHINE* \
+    | -subsystem* | -SUBSYSTEM* \
+    | -verbose | -VERBOSE \
+    | -wx* | -WX* )
+      AR="$AR $1"
+      shift
+      ;;
+    *)
+      action=$1
+      shift
+      break
+      ;;
+  esac
+done
+orig_archive=$1
+shift
+func_file_conv "$orig_archive"
+archive=$file
+
+# strip leading dash in $action
+action=${action#-}
+
+delete=
+extract=
+list=
+quick=
+replace=
+index=
+create=
+
+while test -n "$action"
+do
+  case $action in
+    d*) delete=yes  ;;
+    x*) extract=yes ;;
+    t*) list=yes    ;;
+    q*) quick=yes   ;;
+    r*) replace=yes ;;
+    s*) index=yes   ;;
+    S*)             ;; # the index is always updated implicitly
+    c*) create=yes  ;;
+    u*)             ;; # TODO: don't ignore the update modifier
+    v*)             ;; # TODO: don't ignore the verbose modifier
+    *)
+      func_error "unknown action specified"
+      ;;
+  esac
+  action=${action#?}
+done
+
+case $delete$extract$list$quick$replace,$index in
+  yes,* | ,yes)
+    ;;
+  yesyes*)
+    func_error "more than one action specified"
+    ;;
+  *)
+    func_error "no action specified"
+    ;;
+esac
+
+if test -n "$delete"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  for member
+  do
+    case $1 in
+      @*)
+        func_at_file "${1#@}" -REMOVE "$archive"
+        ;;
+      *)
+        func_file_conv "$1"
+        $AR -NOLOGO -REMOVE:"$file" "$archive" || exit $?
+        ;;
+    esac
+  done
+
+elif test -n "$extract"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  if test $# -gt 0; then
+    for member
+    do
+      case $1 in
+        @*)
+          func_at_file "${1#@}" -EXTRACT "$archive"
+          ;;
+        *)
+          func_file_conv "$1"
+          $AR -NOLOGO -EXTRACT:"$file" "$archive" || exit $?
+          ;;
+      esac
+    done
+  else
+    $AR -NOLOGO -LIST "$archive" | sed -e 's/\\/\\\\/g' | while read member
+    do
+      $AR -NOLOGO -EXTRACT:"$member" "$archive" || exit $?
+    done
+  fi
+
+elif test -n "$quick$replace"; then
+  if test ! -f "$orig_archive"; then
+    if test -z "$create"; then
+      echo "$me: creating $orig_archive"
+    fi
+    orig_archive=
+  else
+    orig_archive=$archive
+  fi
+
+  for member
+  do
+    case $1 in
+    @*)
+      func_file_conv "${1#@}"
+      set x "$@" "@$file"
+      ;;
+    *)
+      func_file_conv "$1"
+      set x "$@" "$file"
+      ;;
+    esac
+    shift
+    shift
+  done
+
+  if test -n "$orig_archive"; then
+    $AR -NOLOGO -OUT:"$archive" "$orig_archive" "$@" || exit $?
+  else
+    $AR -NOLOGO -OUT:"$archive" "$@" || exit $?
+  fi
+
+elif test -n "$list"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  $AR -NOLOGO -LIST "$archive" || exit $?
+fi