configure: add DOLT

Shorten build time.

On x86_64 linux build:

LIBTOOL make -j2  60,82s user 13,98s system 112% cpu 1:06,59 total
        make -j2  56,83s user 12,72s system 110% cpu 1:03,20 total
DOLT    make -j2  44,32s user 11,02s system 108% cpu 51,215 total
        make -j2  42,15s user 11,04s system 106% cpu 50,155 total
Signed-off-by: Rafaël Carré <funman@videolan.org>

configure.ac

@@ -390,6 +390,8 @@ LT_INIT([dlopen win32-dll shared disable-static])
 LT_LANG([C++])
 LT_LANG([Windows Resource])
 
+DOLT
+
 m4_undefine([AC_DEPLIBS_CHECK_METHOD])
 m4_defun([AC_DEPLIBS_CHECK_METHOD],[])
 

m4/dolt.m4

+dnl dolt, a replacement for libtool
+dnl Copyright © 2007-2010 Josh Triplett <josh@joshtriplett.org>
+dnl Copying and distribution of this file, with or without modification,
+dnl are permitted in any medium without royalty provided the copyright
+dnl notice and this notice are preserved.
+dnl
+dnl To use dolt, invoke the DOLT macro immediately after the libtool macros.
+dnl Optionally, copy this file into acinclude.m4, to avoid the need to have it
+dnl installed when running autoconf on your project.
+
+AC_DEFUN([DOLT], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+# dolt, a replacement for libtool
+# Josh Triplett <josh@freedesktop.org>
+AC_PATH_PROG(DOLT_BASH, bash)
+AC_MSG_CHECKING([if dolt supports this host])
+dolt_supported=yes
+if test x$DOLT_BASH = x; then
+    dolt_supported=no
+fi
+if test x$GCC != xyes; then
+    dolt_supported=no
+fi
+case $host in
+*-*-linux* \
+|amd64-*-freebsd*|i?86-*-freebsd*|ia64-*-freebsd*)
+    pic_options='-fPIC'
+    ;;
+i?86-apple-darwin*)
+    pic_options='-fno-common'
+    ;;
+*mingw*)
+    pic_options=''
+    ;;
+*)
+    dolt_supported=no
+    ;;
+esac
+if test x$dolt_supported = xno ; then
+    AC_MSG_RESULT([no, falling back to libtool])
+    LTCOMPILE='$(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(COMPILE)'
+    LTCXXCOMPILE='$(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CXXCOMPILE)'
+else
+    AC_MSG_RESULT([yes, replacing libtool])
+
+dnl Start writing out doltcompile.
+    cat <<__DOLTCOMPILE__EOF__ >doltcompile
+#!$DOLT_BASH
+__DOLTCOMPILE__EOF__
+    cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+args=("$[]@")
+for ((arg=0; arg<${#args@<:@@@:>@}; arg++)) ; do
+    if test x"${args@<:@$arg@:>@}" = x-o ; then
+        objarg=$((arg+1))
+        break
+    fi
+done
+if test x$objarg = x ; then
+    echo 'Error: no -o on compiler command line' 1>&2
+    exit 1
+fi
+lo="${args@<:@$objarg@:>@}"
+obj="${lo%.lo}"
+if test x"$lo" = x"$obj" ; then
+    echo "Error: libtool object file name \"$lo\" does not end in .lo" 1>&2
+    exit 1
+fi
+objbase="${obj##*/}"
+__DOLTCOMPILE__EOF__
+
+dnl Write out shared compilation code.
+    if test x$enable_shared = xyes; then
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+libobjdir="${obj%$objbase}.libs"
+if test ! -d "$libobjdir" ; then
+    mkdir_out="$(mkdir "$libobjdir" 2>&1)"
+    mkdir_ret=$?
+    if test "$mkdir_ret" -ne 0 && test ! -d "$libobjdir" ; then
+	echo "$mkdir_out" 1>&2
+        exit $mkdir_ret
+    fi
+fi
+pic_object="$libobjdir/$objbase.o"
+args@<:@$objarg@:>@="$pic_object"
+__DOLTCOMPILE__EOF__
+    cat <<__DOLTCOMPILE__EOF__ >>doltcompile
+"\${args@<:@@@:>@}" $pic_options -DPIC || exit \$?
+__DOLTCOMPILE__EOF__
+    fi
+
+dnl Write out static compilation code.
+dnl Avoid duplicate compiler output if also building shared objects.
+    if test x$enable_static = xyes; then
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+non_pic_object="$obj.o"
+args@<:@$objarg@:>@="$non_pic_object"
+__DOLTCOMPILE__EOF__
+        if test x$enable_shared = xyes; then
+            cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+"${args@<:@@@:>@}" >/dev/null 2>&1 || exit $?
+__DOLTCOMPILE__EOF__
+        else
+            cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+"${args@<:@@@:>@}" || exit $?
+__DOLTCOMPILE__EOF__
+        fi
+    fi
+
+dnl Write out the code to write the .lo file.
+dnl The second line of the .lo file must match "^# Generated by .*libtool"
+    cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+{
+echo "# $lo - a libtool object file"
+echo "# Generated by doltcompile, not libtool"
+__DOLTCOMPILE__EOF__
+
+    if test x$enable_shared = xyes; then
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+echo "pic_object='.libs/${objbase}.o'"
+__DOLTCOMPILE__EOF__
+    else
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+echo pic_object=none
+__DOLTCOMPILE__EOF__
+    fi
+
+    if test x$enable_static = xyes; then
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+echo "non_pic_object='${objbase}.o'"
+__DOLTCOMPILE__EOF__
+    else
+        cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+echo non_pic_object=none
+__DOLTCOMPILE__EOF__
+    fi
+
+    cat <<'__DOLTCOMPILE__EOF__' >>doltcompile
+} > "$lo"
+__DOLTCOMPILE__EOF__
+
+dnl Done writing out doltcompile; substitute it for libtool compilation.
+    chmod +x doltcompile
+    LTCOMPILE='$(top_builddir)/doltcompile $(COMPILE)'
+    LTCXXCOMPILE='$(top_builddir)/doltcompile $(CXXCOMPILE)'
+
+dnl automake ignores LTCOMPILE and LTCXXCOMPILE when it has separate CFLAGS for
+dnl a target, so write out a libtool wrapper to handle that case.
+dnl Note that doltlibtool does not handle inferred tags or option arguments
+dnl without '=', because automake does not use them.
+    cat <<__DOLTLIBTOOL__EOF__ > doltlibtool
+#!$DOLT_BASH
+__DOLTLIBTOOL__EOF__
+    cat <<'__DOLTLIBTOOL__EOF__' >>doltlibtool
+top_builddir_slash="${0%%doltlibtool}"
+: ${top_builddir_slash:=./}
+args=()
+modeok=false
+tagok=false
+for arg in "$[]@"; do
+    case "$arg" in
+        --mode=compile) modeok=true ;;
+        --tag=CC|--tag=CXX) tagok=true ;;
+        --silent|--quiet) ;;
+        *) args@<:@${#args[@]}@:>@="$arg" ;;
+    esac
+done
+if $modeok && $tagok ; then
+    . ${top_builddir_slash}doltcompile "${args@<:@@@:>@}"
+else
+    exec ${top_builddir_slash}libtool "$[]@"
+fi
+__DOLTLIBTOOL__EOF__
+
+dnl Done writing out doltlibtool; substitute it for libtool.
+    chmod +x doltlibtool
+    LIBTOOL='$(top_builddir)/doltlibtool'
+fi
+AC_SUBST(LTCOMPILE)
+AC_SUBST(LTCXXCOMPILE)
+# end dolt
+])