build: detect the right ar tool

Use automake's AM_PROG_AR helper instead of the default of hardcoding
`ar` all the time.  When cross-compiling, this can often be the wrong
one to use.

BUG=google-breakpad:519
R=ted.mielczarek@gmail.com

Review URL: https://codereview.chromium.org/1435813002 .

Makefile.in

@@ -278,7 +278,6 @@ am__installdirs = "$(DESTDIR)$(libdir)" "$(DESTDIR)$(bindir)" \
 	"$(DESTDIR)$(includegbcdir)" "$(DESTDIR)$(includelssdir)" \
 	"$(DESTDIR)$(includepdir)"
 LIBRARIES = $(lib_LIBRARIES) $(noinst_LIBRARIES)
-AR = ar
 ARFLAGS = cru
 AM_V_AR = $(am__v_AR_@AM_V@)
 am__v_AR_ = $(am__v_AR_@AM_DEFAULT_V@)
@@ -1880,7 +1879,7 @@ TEST_LOG_COMPILE = $(TEST_LOG_COMPILER) $(AM_TEST_LOG_FLAGS) \
 	$(TEST_LOG_FLAGS)
 am__DIST_COMMON = $(srcdir)/Makefile.in \
 	$(srcdir)/breakpad-client.pc.in $(srcdir)/breakpad.pc.in \
-	$(top_srcdir)/autotools/compile \
+	$(top_srcdir)/autotools/ar-lib $(top_srcdir)/autotools/compile \
 	$(top_srcdir)/autotools/config.guess \
 	$(top_srcdir)/autotools/config.sub \
 	$(top_srcdir)/autotools/depcomp \
@@ -1888,9 +1887,9 @@ am__DIST_COMMON = $(srcdir)/Makefile.in \
 	$(top_srcdir)/autotools/missing \
 	$(top_srcdir)/autotools/test-driver \
 	$(top_srcdir)/src/config.h.in AUTHORS ChangeLog INSTALL NEWS \
-	autotools/compile autotools/config.guess autotools/config.sub \
+	autotools/ar-lib autotools/compile autotools/config.guess \
-	autotools/depcomp autotools/install-sh autotools/ltmain.sh \
+	autotools/config.sub autotools/depcomp autotools/install-sh \
-	autotools/missing
+	autotools/ltmain.sh autotools/missing
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
@@ -1911,6 +1910,7 @@ distcleancheck_listfiles = find . -type f -print
 ACLOCAL = @ACLOCAL@
 AMTAR = @AMTAR@
 AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
+AR = @AR@
 AUTOCONF = @AUTOCONF@
 AUTOHEADER = @AUTOHEADER@
 AUTOMAKE = @AUTOMAKE@
@@ -1968,6 +1968,7 @@ abs_builddir = @abs_builddir@
 abs_srcdir = @abs_srcdir@
 abs_top_builddir = @abs_top_builddir@
 abs_top_srcdir = @abs_top_srcdir@
+ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_CXX = @ac_ct_CXX@
 am__include = @am__include@

aclocal.m4

@@ -56,6 +56,66 @@ m4_ifndef([AC_AUTOCONF_VERSION],
   [m4_copy([m4_PACKAGE_VERSION], [AC_AUTOCONF_VERSION])])dnl
 _AM_AUTOCONF_VERSION(m4_defn([AC_AUTOCONF_VERSION]))])
 
+# Copyright (C) 2011-2014 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# AM_PROG_AR([ACT-IF-FAIL])
+# -------------------------
+# Try to determine the archiver interface, and trigger the ar-lib wrapper
+# if it is needed.  If the detection of archiver interface fails, run
+# ACT-IF-FAIL (default is to abort configure with a proper error message).
+AC_DEFUN([AM_PROG_AR],
+[AC_BEFORE([$0], [LT_INIT])dnl
+AC_BEFORE([$0], [AC_PROG_LIBTOOL])dnl
+AC_REQUIRE([AM_AUX_DIR_EXPAND])dnl
+AC_REQUIRE_AUX_FILE([ar-lib])dnl
+AC_CHECK_TOOLS([AR], [ar lib "link -lib"], [false])
+: ${AR=ar}
+
+AC_CACHE_CHECK([the archiver ($AR) interface], [am_cv_ar_interface],
+  [AC_LANG_PUSH([C])
+   am_cv_ar_interface=ar
+   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[int some_variable = 0;]])],
+     [am_ar_try='$AR cru libconftest.a conftest.$ac_objext >&AS_MESSAGE_LOG_FD'
+      AC_TRY_EVAL([am_ar_try])
+      if test "$ac_status" -eq 0; then
+        am_cv_ar_interface=ar
+      else
+        am_ar_try='$AR -NOLOGO -OUT:conftest.lib conftest.$ac_objext >&AS_MESSAGE_LOG_FD'
+        AC_TRY_EVAL([am_ar_try])
+        if test "$ac_status" -eq 0; then
+          am_cv_ar_interface=lib
+        else
+          am_cv_ar_interface=unknown
+        fi
+      fi
+      rm -f conftest.lib libconftest.a
+     ])
+   AC_LANG_POP([C])])
+
+case $am_cv_ar_interface in
+ar)
+  ;;
+lib)
+  # Microsoft lib, so override with the ar-lib wrapper script.
+  # FIXME: It is wrong to rewrite AR.
+  # But if we don't then we get into trouble of one sort or another.
+  # A longer-term fix would be to have automake use am__AR in this case,
+  # and then we could set am__AR="$am_aux_dir/ar-lib \$(AR)" or something
+  # similar.
+  AR="$am_aux_dir/ar-lib $AR"
+  ;;
+unknown)
+  m4_default([$1],
+             [AC_MSG_ERROR([could not determine $AR interface])])
+  ;;
+esac
+AC_SUBST([AR])dnl
+])
+
 # Figure out how to run the assembler.                      -*- Autoconf -*-
 
 # Copyright (C) 2001-2014 Free Software Foundation, Inc.

autotools/ar-lib

@@ -0,0 +1,270 @@
+#! /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

configure

@@ -674,6 +674,8 @@ CPPFLAGS
 LDFLAGS
 CFLAGS
 CC
+ac_ct_AR
+AR
 MAINT
 MAINTAINER_MODE_FALSE
 MAINTAINER_MODE_TRUE
@@ -4041,6 +4043,178 @@ else
 fi
 
 
+
+if test -n "$ac_tool_prefix"; then
+  for ac_prog in ar lib "link -lib"
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_AR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$AR"; then
+  ac_cv_prog_AR="$AR" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_AR="$ac_tool_prefix$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+AR=$ac_cv_prog_AR
+if test -n "$AR"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $AR" >&5
+$as_echo "$AR" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+    test -n "$AR" && break
+  done
+fi
+if test -z "$AR"; then
+  ac_ct_AR=$AR
+  for ac_prog in ar lib "link -lib"
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_AR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_AR"; then
+  ac_cv_prog_ac_ct_AR="$ac_ct_AR" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_AR="$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_AR=$ac_cv_prog_ac_ct_AR
+if test -n "$ac_ct_AR"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_AR" >&5
+$as_echo "$ac_ct_AR" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$ac_ct_AR" && break
+done
+
+  if test "x$ac_ct_AR" = x; then
+    AR="false"
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    AR=$ac_ct_AR
+  fi
+fi
+
+: ${AR=ar}
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking the archiver ($AR) interface" >&5
+$as_echo_n "checking the archiver ($AR) interface... " >&6; }
+if ${am_cv_ar_interface+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+   am_cv_ar_interface=ar
+   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+int some_variable = 0;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  am_ar_try='$AR cru libconftest.a conftest.$ac_objext >&5'
+      { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$am_ar_try\""; } >&5
+  (eval $am_ar_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+      if test "$ac_status" -eq 0; then
+        am_cv_ar_interface=ar
+      else
+        am_ar_try='$AR -NOLOGO -OUT:conftest.lib conftest.$ac_objext >&5'
+        { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$am_ar_try\""; } >&5
+  (eval $am_ar_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+        if test "$ac_status" -eq 0; then
+          am_cv_ar_interface=lib
+        else
+          am_cv_ar_interface=unknown
+        fi
+      fi
+      rm -f conftest.lib libconftest.a
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+   ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $am_cv_ar_interface" >&5
+$as_echo "$am_cv_ar_interface" >&6; }
+
+case $am_cv_ar_interface in
+ar)
+  ;;
+lib)
+  # Microsoft lib, so override with the ar-lib wrapper script.
+  # FIXME: It is wrong to rewrite AR.
+  # But if we don't then we get into trouble of one sort or another.
+  # A longer-term fix would be to have automake use am__AR in this case,
+  # and then we could set am__AR="$am_aux_dir/ar-lib \$(AR)" or something
+  # similar.
+  AR="$am_aux_dir/ar-lib $AR"
+  ;;
+unknown)
+  as_fn_error $? "could not determine $AR interface" "$LINENO" 5
+  ;;
+esac
+
 # By default we simply use the C compiler to build assembly code.
 
 test "${CCAS+set}" = set || CCAS=$CC
@@ -5545,7 +5719,6 @@ fi
 
 
 
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for grep that handles long lines and -e" >&5
 $as_echo_n "checking for grep that handles long lines and -e... " >&6; }
 if ${ac_cv_path_GREP+:} false; then :

configure.ac

@@ -41,6 +41,7 @@ AM_INIT_AUTOMAKE(subdir-objects tar-ustar 1.11.1)
 AM_CONFIG_HEADER(src/config.h)
 AM_MAINTAINER_MODE
 
+AM_PROG_AR
 AM_PROG_AS
 AC_PROG_CC
 AM_PROG_CC_C_O