diff mbox series

PR preprocessor/94657: use $AR, not 'ar',

Message ID 20200422220538.3611122-1-slyfox@inbox.ru
State New
Headers show
Series PR preprocessor/94657: use $AR, not 'ar', | expand

Commit Message

Sergei Trofimovich April 22, 2020, 10:05 p.m. UTC
From: Sergei Trofimovich <siarheit@google.com>

On system with 'ar' and '${CHOST}-ar' the latter is preferred.
as it might not match default 'ar'.

Bug is initially reported downstream as https://bugs.gentoo.org/718004.

libcpp/ChangeLog:

	PR libcpp/94657
	* Makefile.in: use @AR@ placeholder
	* configure.ac: use AC_CHECK_TOOL to find 'ar'
	* configure: regenerate
---
 libcpp/ChangeLog    |  7 ++++
 libcpp/Makefile.in  |  2 +-
 libcpp/configure    | 94 +++++++++++++++++++++++++++++++++++++++++++++
 libcpp/configure.ac |  1 +
 4 files changed, 103 insertions(+), 1 deletion(-)

Comments

Sergei Trofimovich May 7, 2020, 7:18 a.m. UTC | #1
On Wed, 22 Apr 2020 23:05:38 +0100
Sergei Trofimovich <slyfox@inbox.ru> wrote:

> From: Sergei Trofimovich <siarheit@google.com>
> 
> On system with 'ar' and '${CHOST}-ar' the latter is preferred.
> as it might not match default 'ar'.
> 
> Bug is initially reported downstream as https://bugs.gentoo.org/718004.
> 
> libcpp/ChangeLog:
> 
> 	PR libcpp/94657
> 	* Makefile.in: use @AR@ placeholder
> 	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> 	* configure: regenerate
> ---
>  libcpp/ChangeLog    |  7 ++++
>  libcpp/Makefile.in  |  2 +-
>  libcpp/configure    | 94 +++++++++++++++++++++++++++++++++++++++++++++
>  libcpp/configure.ac |  1 +
>  4 files changed, 103 insertions(+), 1 deletion(-)
> 
> diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
> index 307cf3add94..77145768a3d 100644
> --- a/libcpp/ChangeLog
> +++ b/libcpp/ChangeLog
> @@ -1,3 +1,10 @@
> +2020-04-22  Sergei Trofimovich  <siarheit@google.com>
> +
> +	PR preprocessor/94657: use $AR, not 'ar'
> +	* Makefile.in: use @AR@ placeholder
> +	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> +	* configure: regenerate
> +
>  2020-02-14  Jakub Jelinek  <jakub@redhat.com>
>  
>  	Partially implement P1042R1: __VA_OPT__ wording clarifications
> diff --git a/libcpp/Makefile.in b/libcpp/Makefile.in
> index 8f8c8f65eb3..af7a0c6f73e 100644
> --- a/libcpp/Makefile.in
> +++ b/libcpp/Makefile.in
> @@ -25,7 +25,7 @@ srcdir = @srcdir@
>  top_builddir = .
>  VPATH = @srcdir@
>  INSTALL = @INSTALL@
> -AR = ar
> +AR = @AR@
>  ARFLAGS = cru
>  ACLOCAL = @ACLOCAL@
>  AUTOCONF = @AUTOCONF@
> diff --git a/libcpp/configure b/libcpp/configure
> index 11da199083b..a6dcf5dcb61 100755
> --- a/libcpp/configure
> +++ b/libcpp/configure
> @@ -657,6 +657,7 @@ ACLOCAL
>  EGREP
>  GREP
>  CPP
> +AR
>  RANLIB
>  ac_ct_CXX
>  CXXFLAGS
> @@ -1039,6 +1040,7 @@ do
>    | -silent | --silent | --silen | --sile | --sil)
>      silent=yes ;;
>  
> +
>    -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
>      ac_prev=sbindir ;;
>    -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
> @@ -4008,6 +4010,98 @@ else
>    RANLIB="$ac_cv_prog_RANLIB"
>  fi
>  
> +if test -n "$ac_tool_prefix"; then
> +  # Extract the first word of "${ac_tool_prefix}ar", so it can be a program name with args.
> +set dummy ${ac_tool_prefix}ar; 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}ar"
> +    $as_echo "$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
> +$as_echo "no" >&6; }
> +fi
> +
> +
> +fi
> +if test -z "$ac_cv_prog_AR"; then
> +  ac_ct_AR=$AR
> +  # Extract the first word of "ar", so it can be a program name with args.
> +set dummy ar; 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="ar"
> +    $as_echo "$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
> +$as_echo "no" >&6; }
> +fi
> +
> +  if test "x$ac_ct_AR" = x; then
> +    AR=""
> +  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=$ac_ct_AR
> +  fi
> +else
> +  AR="$ac_cv_prog_AR"
> +fi
> +
>  
>  
>  ac_ext=c
> diff --git a/libcpp/configure.ac b/libcpp/configure.ac
> index 1779562a3a7..9ccfb02aa13 100644
> --- a/libcpp/configure.ac
> +++ b/libcpp/configure.ac
> @@ -12,6 +12,7 @@ AC_PROG_INSTALL
>  AC_PROG_CC
>  AC_PROG_CXX
>  AC_PROG_RANLIB
> +AC_CHECK_TOOL(AR, ar)
>  
>  AC_USE_SYSTEM_EXTENSIONS
>  AC_SYS_LARGEFILE
> -- 
> 2.26.2
> 

Ping.
Sergei Trofimovich May 28, 2020, 11:15 p.m. UTC | #2
On Thu, 7 May 2020 08:18:31 +0100
Sergei Trofimovich via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:

> On Wed, 22 Apr 2020 23:05:38 +0100
> Sergei Trofimovich <slyfox@inbox.ru> wrote:
> 
> > From: Sergei Trofimovich <siarheit@google.com>
> > 
> > On system with 'ar' and '${CHOST}-ar' the latter is preferred.
> > as it might not match default 'ar'.
> > 
> > Bug is initially reported downstream as https://bugs.gentoo.org/718004.
> > 
> > libcpp/ChangeLog:
> > 
> > 	PR libcpp/94657
> > 	* Makefile.in: use @AR@ placeholder
> > 	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> > 	* configure: regenerate
> > ---
> >  libcpp/ChangeLog    |  7 ++++
> >  libcpp/Makefile.in  |  2 +-
> >  libcpp/configure    | 94 +++++++++++++++++++++++++++++++++++++++++++++
> >  libcpp/configure.ac |  1 +
> >  4 files changed, 103 insertions(+), 1 deletion(-)
> > 
> > diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
> > index 307cf3add94..77145768a3d 100644
> > --- a/libcpp/ChangeLog
> > +++ b/libcpp/ChangeLog
> > @@ -1,3 +1,10 @@
> > +2020-04-22  Sergei Trofimovich  <siarheit@google.com>
> > +
> > +	PR preprocessor/94657: use $AR, not 'ar'
> > +	* Makefile.in: use @AR@ placeholder
> > +	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> > +	* configure: regenerate
> > +
> >  2020-02-14  Jakub Jelinek  <jakub@redhat.com>
> >  
> >  	Partially implement P1042R1: __VA_OPT__ wording clarifications
> > diff --git a/libcpp/Makefile.in b/libcpp/Makefile.in
> > index 8f8c8f65eb3..af7a0c6f73e 100644
> > --- a/libcpp/Makefile.in
> > +++ b/libcpp/Makefile.in
> > @@ -25,7 +25,7 @@ srcdir = @srcdir@
> >  top_builddir = .
> >  VPATH = @srcdir@
> >  INSTALL = @INSTALL@
> > -AR = ar
> > +AR = @AR@
> >  ARFLAGS = cru
> >  ACLOCAL = @ACLOCAL@
> >  AUTOCONF = @AUTOCONF@
> > diff --git a/libcpp/configure b/libcpp/configure
> > index 11da199083b..a6dcf5dcb61 100755
> > --- a/libcpp/configure
> > +++ b/libcpp/configure
> > @@ -657,6 +657,7 @@ ACLOCAL
> >  EGREP
> >  GREP
> >  CPP
> > +AR
> >  RANLIB
> >  ac_ct_CXX
> >  CXXFLAGS
> > @@ -1039,6 +1040,7 @@ do
> >    | -silent | --silent | --silen | --sile | --sil)
> >      silent=yes ;;
> >  
> > +
> >    -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
> >      ac_prev=sbindir ;;
> >    -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
> > @@ -4008,6 +4010,98 @@ else
> >    RANLIB="$ac_cv_prog_RANLIB"
> >  fi
> >  
> > +if test -n "$ac_tool_prefix"; then
> > +  # Extract the first word of "${ac_tool_prefix}ar", so it can be a program name with args.
> > +set dummy ${ac_tool_prefix}ar; 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}ar"
> > +    $as_echo "$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
> > +$as_echo "no" >&6; }
> > +fi
> > +
> > +
> > +fi
> > +if test -z "$ac_cv_prog_AR"; then
> > +  ac_ct_AR=$AR
> > +  # Extract the first word of "ar", so it can be a program name with args.
> > +set dummy ar; 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="ar"
> > +    $as_echo "$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
> > +$as_echo "no" >&6; }
> > +fi
> > +
> > +  if test "x$ac_ct_AR" = x; then
> > +    AR=""
> > +  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=$ac_ct_AR
> > +  fi
> > +else
> > +  AR="$ac_cv_prog_AR"
> > +fi
> > +
> >  
> >  
> >  ac_ext=c
> > diff --git a/libcpp/configure.ac b/libcpp/configure.ac
> > index 1779562a3a7..9ccfb02aa13 100644
> > --- a/libcpp/configure.ac
> > +++ b/libcpp/configure.ac
> > @@ -12,6 +12,7 @@ AC_PROG_INSTALL
> >  AC_PROG_CC
> >  AC_PROG_CXX
> >  AC_PROG_RANLIB
> > +AC_CHECK_TOOL(AR, ar)
> >  
> >  AC_USE_SYSTEM_EXTENSIONS
> >  AC_SYS_LARGEFILE
> > -- 
> > 2.26.2
> >   
> 
> Ping.

On #gcc Tobias pointed out that similar patch was merged a few days ago:
    https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=731c4ce0e93065fb70db5faa2bd6c9c6bad56738
    https://gcc.gnu.org/pipermail/gcc-patches/2020-May/546337.html

This patch is obsolete.
Jeff Law Nov. 13, 2020, 6:45 p.m. UTC | #3
On 4/22/20 4:05 PM, Sergei Trofimovich wrote:
> From: Sergei Trofimovich <siarheit@google.com>
>
> On system with 'ar' and '${CHOST}-ar' the latter is preferred.
> as it might not match default 'ar'.
>
> Bug is initially reported downstream as https://bugs.gentoo.org/718004.
>
> libcpp/ChangeLog:
>
> 	PR libcpp/94657
> 	* Makefile.in: use @AR@ placeholder
> 	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> 	* configure: regenerate

This was subsumed by David Edelsohn's patch to libcpp and libdecnumber
which does effectively the same thing.

jeff
Sergei Trofimovich Nov. 13, 2020, 7:41 p.m. UTC | #4
On Fri, 13 Nov 2020 11:45:56 -0700
Jeff Law <law@redhat.com> wrote:

> 
> On 4/22/20 4:05 PM, Sergei Trofimovich wrote:
> > From: Sergei Trofimovich <siarheit@google.com>
> >
> > On system with 'ar' and '${CHOST}-ar' the latter is preferred.
> > as it might not match default 'ar'.
> >
> > Bug is initially reported downstream as https://bugs.gentoo.org/718004.
> >
> > libcpp/ChangeLog:
> >
> > 	PR libcpp/94657
> > 	* Makefile.in: use @AR@ placeholder
> > 	* configure.ac: use AC_CHECK_TOOL to find 'ar'
> > 	* configure: regenerate
> 
> This was subsumed by David Edelsohn's patch to libcpp and libdecnumber
> which does effectively the same thing.

Agreed. It was also mentioned in
  https://gcc.gnu.org/pipermail/gcc-patches/2020-May/546756.html
Probably should not have changed the topic to be mre visible.
diff mbox series

Patch

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 307cf3add94..77145768a3d 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,10 @@ 
+2020-04-22  Sergei Trofimovich  <siarheit@google.com>
+
+	PR preprocessor/94657: use $AR, not 'ar'
+	* Makefile.in: use @AR@ placeholder
+	* configure.ac: use AC_CHECK_TOOL to find 'ar'
+	* configure: regenerate
+
 2020-02-14  Jakub Jelinek  <jakub@redhat.com>
 
 	Partially implement P1042R1: __VA_OPT__ wording clarifications
diff --git a/libcpp/Makefile.in b/libcpp/Makefile.in
index 8f8c8f65eb3..af7a0c6f73e 100644
--- a/libcpp/Makefile.in
+++ b/libcpp/Makefile.in
@@ -25,7 +25,7 @@  srcdir = @srcdir@
 top_builddir = .
 VPATH = @srcdir@
 INSTALL = @INSTALL@
-AR = ar
+AR = @AR@
 ARFLAGS = cru
 ACLOCAL = @ACLOCAL@
 AUTOCONF = @AUTOCONF@
diff --git a/libcpp/configure b/libcpp/configure
index 11da199083b..a6dcf5dcb61 100755
--- a/libcpp/configure
+++ b/libcpp/configure
@@ -657,6 +657,7 @@  ACLOCAL
 EGREP
 GREP
 CPP
+AR
 RANLIB
 ac_ct_CXX
 CXXFLAGS
@@ -1039,6 +1040,7 @@  do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -4008,6 +4010,98 @@  else
   RANLIB="$ac_cv_prog_RANLIB"
 fi
 
+if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}ar", so it can be a program name with args.
+set dummy ${ac_tool_prefix}ar; 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}ar"
+    $as_echo "$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
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_prog_AR"; then
+  ac_ct_AR=$AR
+  # Extract the first word of "ar", so it can be a program name with args.
+set dummy ar; 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="ar"
+    $as_echo "$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
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_ct_AR" = x; then
+    AR=""
+  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=$ac_ct_AR
+  fi
+else
+  AR="$ac_cv_prog_AR"
+fi
+
 
 
 ac_ext=c
diff --git a/libcpp/configure.ac b/libcpp/configure.ac
index 1779562a3a7..9ccfb02aa13 100644
--- a/libcpp/configure.ac
+++ b/libcpp/configure.ac
@@ -12,6 +12,7 @@  AC_PROG_INSTALL
 AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_RANLIB
+AC_CHECK_TOOL(AR, ar)
 
 AC_USE_SYSTEM_EXTENSIONS
 AC_SYS_LARGEFILE