Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/m4/acx_pthread.m4

Index: third_party/protobuf/m4/acx_pthread.m4
diff --git a/third_party/protobuf/m4/acx_pthread.m4 b/third_party/protobuf/m4/acx_pthread.m4
deleted file mode 100644
index 89d42c7449ef3aeef8c6c6ab96fc3e1dbc306deb..0000000000000000000000000000000000000000
--- a/third_party/protobuf/m4/acx_pthread.m4
+++ /dev/null
@@ -1,397 +0,0 @@
-# This was retrieved from
-#    http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?revision=1277&root=avahi
-# See also (perhaps for new versions?)
-#    http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?root=avahi
-#
-# We've rewritten the inconsistency check code (from avahi), to work
-# more broadly.  In particular, it no longer assumes ld accepts -zdefs.
-# This caused a restructing of the code, but the functionality has only
-# changed a little.
-
-dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
-dnl
-dnl @summary figure out how to build C programs using POSIX threads
-dnl
-dnl This macro figures out how to build C programs using POSIX threads.
-dnl It sets the PTHREAD_LIBS output variable to the threads library and
-dnl linker flags, and the PTHREAD_CFLAGS output variable to any special
-dnl C compiler flags that are needed. (The user can also force certain
-dnl compiler flags/libs to be tested by setting these environment
-dnl variables.)
-dnl
-dnl Also sets PTHREAD_CC to any special C compiler that is needed for
-dnl multi-threaded programs (defaults to the value of CC otherwise).
-dnl (This is necessary on AIX to use the special cc_r compiler alias.)
-dnl
-dnl NOTE: You are assumed to not only compile your program with these
-dnl flags, but also link it with them as well. e.g. you should link
-dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
-dnl $LIBS
-dnl
-dnl If you are only building threads programs, you may wish to use
-dnl these variables in your default LIBS, CFLAGS, and CC:
-dnl
-dnl        LIBS="$PTHREAD_LIBS $LIBS"
-dnl        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-dnl        CC="$PTHREAD_CC"
-dnl
-dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
-dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
-dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
-dnl
-dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
-dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to
-dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the
-dnl default action will define HAVE_PTHREAD.
-dnl
-dnl Please let the authors know if this macro fails on any platform, or
-dnl if you have any other suggestions or comments. This macro was based
-dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with
-dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros
-dnl posted by Alejandro Forero Cuervo to the autoconf macro repository.
-dnl We are also grateful for the helpful feedback of numerous users.
-dnl
-dnl @category InstalledPackages
-dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
-dnl @version 2006-05-29
-dnl @license GPLWithACException
-dnl 
-dnl Checks for GCC shared/pthread inconsistency based on work by
-dnl Marcin Owsiany <marcin@owsiany.pl>
-
-
-AC_DEFUN([ACX_PTHREAD], [
-AC_REQUIRE([AC_CANONICAL_HOST])
-AC_LANG_SAVE
-AC_LANG_C
-acx_pthread_ok=no
-
-# We used to check for pthread.h first, but this fails if pthread.h
-# requires special compiler flags (e.g. on True64 or Sequent).
-# It gets checked for in the link test anyway.
-
-# First of all, check if the user has set any of the PTHREAD_LIBS,
-# etcetera environment variables, and if threads linking works using
-# them:
-if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
-        save_CFLAGS="$CFLAGS"
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-        save_LIBS="$LIBS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
-        AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
-        AC_MSG_RESULT($acx_pthread_ok)
-        if test x"$acx_pthread_ok" = xno; then
-                PTHREAD_LIBS=""
-                PTHREAD_CFLAGS=""
-        fi
-        LIBS="$save_LIBS"
-        CFLAGS="$save_CFLAGS"
-fi
-
-# We must check for the threads library under a number of different
-# names; the ordering is very important because some systems
-# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
-# libraries is broken (non-POSIX).
-
-# Create a list of thread flags to try.  Items starting with a "-" are
-# C compiler flags, and other items are library names, except for "none"
-# which indicates that we try without any flags at all, and "pthread-config"
-# which is a program returning the flags for the Pth emulation library.
-
-acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
-
-# The ordering *is* (sometimes) important.  Some notes on the
-# individual items follow:
-
-# pthreads: AIX (must check this before -lpthread)
-# none: in case threads are in libc; should be tried before -Kthread and
-#       other compiler flags to prevent continual compiler warnings
-# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
-# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
-# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
-# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
-# -pthreads: Solaris/gcc
-# -mthreads: Mingw32/gcc, Lynx/gcc
-# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
-#      doesn't hurt to check since this sometimes defines pthreads too;
-#      also defines -D_REENTRANT)
-#      ... -mt is also the pthreads flag for HP/aCC
-# pthread: Linux, etcetera
-# --thread-safe: KAI C++
-# pthread-config: use pthread-config program (for GNU Pth library)
-
-case "${host_cpu}-${host_os}" in
-        *solaris*)
-
-        # On Solaris (at least, for some versions), libc contains stubbed
-        # (non-functional) versions of the pthreads routines, so link-based
-        # tests will erroneously succeed.  (We need to link with -pthreads/-mt/
-        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
-        # a function called by this macro, so we could check for that, but
-        # who knows whether they'll stub that too in a future libc.)  So,
-        # we'll just look for -pthreads and -lpthread first:
-
-        acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
-        ;;
-esac
-
-if test x"$acx_pthread_ok" = xno; then
-for flag in $acx_pthread_flags; do
-
-        case $flag in
-                none)
-                AC_MSG_CHECKING([whether pthreads work without any flags])
-                ;;
-
-                -*)
-                AC_MSG_CHECKING([whether pthreads work with $flag])
-                PTHREAD_CFLAGS="$flag"
-                ;;
-
-		pthread-config)
-		AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
-		if test x"$acx_pthread_config" = xno; then continue; fi
-		PTHREAD_CFLAGS="`pthread-config --cflags`"
-		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
-		;;
-
-                *)
-                AC_MSG_CHECKING([for the pthreads library -l$flag])
-                PTHREAD_LIBS="-l$flag"
-                ;;
-        esac
-
-        save_LIBS="$LIBS"
-        save_CFLAGS="$CFLAGS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-
-        # Check for various functions.  We must include pthread.h,
-        # since some functions may be macros.  (On the Sequent, we
-        # need a special flag -Kthread to make this header compile.)
-        # We check for pthread_join because it is in -lpthread on IRIX
-        # while pthread_create is in libc.  We check for pthread_attr_init
-        # due to DEC craziness with -lpthreads.  We check for
-        # pthread_cleanup_push because it is one of the few pthread
-        # functions on Solaris that doesn't have a non-functional libc stub.
-        # We try pthread_create on general principles.
-        AC_TRY_LINK([#include <pthread.h>],
-                    [pthread_t th; pthread_join(th, 0);
-                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
-                     pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-                    [acx_pthread_ok=yes])
-
-        LIBS="$save_LIBS"
-        CFLAGS="$save_CFLAGS"
-
-        AC_MSG_RESULT($acx_pthread_ok)
-        if test "x$acx_pthread_ok" = xyes; then
-                break;
-        fi
-
-        PTHREAD_LIBS=""
-        PTHREAD_CFLAGS=""
-done
-fi
-
-# Various other checks:
-if test "x$acx_pthread_ok" = xyes; then
-        save_LIBS="$LIBS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-        save_CFLAGS="$CFLAGS"
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-
-        # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
-	AC_MSG_CHECKING([for joinable pthread attribute])
-	attr_name=unknown
-	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
-	    AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
-                        [attr_name=$attr; break])
-	done
-        AC_MSG_RESULT($attr_name)
-        if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
-            AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
-                               [Define to necessary symbol if this constant
-                                uses a non-standard name on your system.])
-        fi
-
-        AC_MSG_CHECKING([if more special flags are required for pthreads])
-        flag=no
-        case "${host_cpu}-${host_os}" in
-            *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
-            *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
-        esac
-        AC_MSG_RESULT(${flag})
-        if test "x$flag" != xno; then
-            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
-        fi
-
-        LIBS="$save_LIBS"
-        CFLAGS="$save_CFLAGS"
-        # More AIX lossage: must compile with xlc_r or cc_r
-	if test x"$GCC" != xyes; then
-          AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
-        else
-          PTHREAD_CC=$CC
-	fi
-
-	# The next part tries to detect GCC inconsistency with -shared on some
-	# architectures and systems. The problem is that in certain
-	# configurations, when -shared is specified, GCC "forgets" to
-	# internally use various flags which are still necessary.
-	
-	#
-	# Prepare the flags
-	#
-	save_CFLAGS="$CFLAGS"
-	save_LIBS="$LIBS"
-	save_CC="$CC"
-	
-	# Try with the flags determined by the earlier checks.
-	#
-	# -Wl,-z,defs forces link-time symbol resolution, so that the
-	# linking checks with -shared actually have any value
-	#
-	# FIXME: -fPIC is required for -shared on many architectures,
-	# so we specify it here, but the right way would probably be to
-	# properly detect whether it is actually required.
-	CFLAGS="-shared -fPIC -Wl,-z,defs $CFLAGS $PTHREAD_CFLAGS"
-	LIBS="$PTHREAD_LIBS $LIBS"
-	CC="$PTHREAD_CC"
-	
-	# In order not to create several levels of indentation, we test
-	# the value of "$done" until we find the cure or run out of ideas.
-	done="no"
-	
-	# First, make sure the CFLAGS we added are actually accepted by our
-	# compiler.  If not (and OS X's ld, for instance, does not accept -z),
-	# then we can't do this test.
-	if test x"$done" = xno; then
-	   AC_MSG_CHECKING([whether to check for GCC pthread/shared inconsistencies])
-	   AC_TRY_LINK(,, , [done=yes])
-	
-	   if test "x$done" = xyes ; then
-	      AC_MSG_RESULT([no])
-	   else
-	      AC_MSG_RESULT([yes])
-	   fi
-	fi
-	
-	if test x"$done" = xno; then
-	   AC_MSG_CHECKING([whether -pthread is sufficient with -shared])
-	   AC_TRY_LINK([#include <pthread.h>],
-	      [pthread_t th; pthread_join(th, 0);
-	      pthread_attr_init(0); pthread_cleanup_push(0, 0);
-	      pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-	      [done=yes])
-	   
-	   if test "x$done" = xyes; then
-	      AC_MSG_RESULT([yes])
-	   else
-	      AC_MSG_RESULT([no])
-	   fi
-	fi
-	
-	#
-	# Linux gcc on some architectures such as mips/mipsel forgets
-	# about -lpthread
-	#
-	if test x"$done" = xno; then
-	   AC_MSG_CHECKING([whether -lpthread fixes that])
-	   LIBS="-lpthread $PTHREAD_LIBS $save_LIBS"
-	   AC_TRY_LINK([#include <pthread.h>],
-	      [pthread_t th; pthread_join(th, 0);
-	      pthread_attr_init(0); pthread_cleanup_push(0, 0);
-	      pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-	      [done=yes])
-	
-	   if test "x$done" = xyes; then
-	      AC_MSG_RESULT([yes])
-	      PTHREAD_LIBS="-lpthread $PTHREAD_LIBS"
-	   else
-	      AC_MSG_RESULT([no])
-	   fi
-	fi
-	#
-	# FreeBSD 4.10 gcc forgets to use -lc_r instead of -lc
-	#
-	if test x"$done" = xno; then
-	   AC_MSG_CHECKING([whether -lc_r fixes that])
-	   LIBS="-lc_r $PTHREAD_LIBS $save_LIBS"
-	   AC_TRY_LINK([#include <pthread.h>],
-	       [pthread_t th; pthread_join(th, 0);
-	        pthread_attr_init(0); pthread_cleanup_push(0, 0);
-	        pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-	       [done=yes])
-	
-	   if test "x$done" = xyes; then
-	      AC_MSG_RESULT([yes])
-	      PTHREAD_LIBS="-lc_r $PTHREAD_LIBS"
-	   else
-	      AC_MSG_RESULT([no])
-	   fi
-	fi
-	if test x"$done" = xno; then
-	   # OK, we have run out of ideas
-	   AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries])
-	
-	   # so it's not safe to assume that we may use pthreads
-	   acx_pthread_ok=no
-	fi
-	
-	AC_MSG_CHECKING([whether what we have so far is sufficient with -nostdlib])
-	CFLAGS="-nostdlib $CFLAGS"
-	# we need c with nostdlib
-	LIBS="$LIBS -lc"
-	AC_TRY_LINK([#include <pthread.h>],
-	      [pthread_t th; pthread_join(th, 0);
-	       pthread_attr_init(0); pthread_cleanup_push(0, 0);
-	       pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-	      [done=yes],[done=no])
-
-	if test "x$done" = xyes; then
-	   AC_MSG_RESULT([yes])
-	else
-	   AC_MSG_RESULT([no])
-	fi
-	
-	if test x"$done" = xno; then
-	   AC_MSG_CHECKING([whether -lpthread saves the day])
-	   LIBS="-lpthread $LIBS"
-	   AC_TRY_LINK([#include <pthread.h>],
-	      [pthread_t th; pthread_join(th, 0);
-	       pthread_attr_init(0); pthread_cleanup_push(0, 0);
-	       pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
-	      [done=yes],[done=no])
-
-	   if test "x$done" = xyes; then
-	      AC_MSG_RESULT([yes])
-	      PTHREAD_LIBS="$PTHREAD_LIBS -lpthread"
-	   else
-	      AC_MSG_RESULT([no])
-	      AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries and -nostdlib])
-	   fi
-	fi
-
-	CFLAGS="$save_CFLAGS"
-	LIBS="$save_LIBS"
-	CC="$save_CC"
-else
-        PTHREAD_CC="$CC"
-fi
-
-AC_SUBST(PTHREAD_LIBS)
-AC_SUBST(PTHREAD_CFLAGS)
-AC_SUBST(PTHREAD_CC)
-
-# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
-if test x"$acx_pthread_ok" = xyes; then
-        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
-        :
-else
-        acx_pthread_ok=no
-        $2
-fi
-AC_LANG_RESTORE
-])dnl ACX_PTHREAD