[1991] moved boost-related config to a separate m4

in order to keep the main configure.ac more concise, and so that we can
eventually introduce more fine-grained configuration (e.g., skipping some
checks for DNS/DHCP-only build)

At the moment, this is just a cleanup, and doesn't change the behavior itself.

configure.ac

@@ -838,57 +838,14 @@ LIBS=$LIBS_SAVED
 #
 # Configure Boost header path
 #
-# If explicitly specified, use it.
-AC_ARG_WITH([boost-include],
-  AC_HELP_STRING([--with-boost-include=PATH],
-    [specify exact directory for Boost headers]),
-    [boost_include_path="$withval"])
-# If not specified, try some common paths.
-if test -z "$with_boost_include"; then
-	boostdirs="/usr/local /usr/pkg /opt /opt/local"
-	for d in $boostdirs
-	do
-		if test -f $d/include/boost/shared_ptr.hpp; then
-			boost_include_path=$d/include
-			break
-		fi
-	done
-fi
-CPPFLAGS_SAVES="$CPPFLAGS"
-if test "${boost_include_path}" ; then
-	BOOST_INCLUDES="-I${boost_include_path}"
-	CPPFLAGS="$CPPFLAGS $BOOST_INCLUDES"
+AX_BOOST_FOR_BIND10
+# Boost offset_ptr is required in one library and not optional right now, so
+# we unconditionally fail here if it doesn't work.
+if test "$BOOST_OFFSET_PTR_FAILURE" == "yes"; then
+    AC_MSG_ERROR([Failed to compile a required header file.  Try upgrading Boost to 1.44 or higher (when using clang++) or specifying --without-werror.  See the ChangeLog entry for Trac no. 2147 for more details.])
 fi
-AC_CHECK_HEADERS([boost/shared_ptr.hpp boost/foreach.hpp boost/interprocess/sync/interprocess_upgradable_mutex.hpp boost/date_time/posix_time/posix_time_types.hpp boost/bind.hpp boost/function.hpp],,
-  AC_MSG_ERROR([Missing required header files.]))
-
-# Detect whether Boost tries to use threads by default, and, if not,
-# make it sure explicitly.  In some systems the automatic detection
-# may depend on preceding header files, and if inconsistency happens
-# it could lead to a critical disruption.
-AC_MSG_CHECKING([whether Boost tries to use threads])
-AC_TRY_COMPILE([
-#include <boost/config.hpp>
-#ifdef BOOST_HAS_THREADS
-#error "boost will use threads"
-#endif],,
-[AC_MSG_RESULT(no)
- CPPFLAGS_BOOST_THREADCONF="-DBOOST_DISABLE_THREADS=1"],
-[AC_MSG_RESULT(yes)])
-
-# Boost offset_ptr is required in one library (not optional right now), and
-# it's known it doesn't compile on some platforms, depending on boost version,
-# its local configuration, and compiler.
-AC_MSG_CHECKING([Boost offset_ptr compiles])
-AC_TRY_COMPILE([
-#include <boost/interprocess/offset_ptr.hpp>
-],,
-[AC_MSG_RESULT(yes)],
-[AC_MSG_RESULT(no)
- AC_MSG_ERROR([Failed to compile a required header file.  Try upgrading Boost to 1.44 or higher (when using clang++) or specifying --without-werror.  See the ChangeLog entry for Trac no. 2147 for more details.])])
 
 CPPFLAGS="$CPPFLAGS_SAVES $CPPFLAGS_BOOST_THREADCONF"
-AC_SUBST(BOOST_INCLUDES)
 
 # I can't get some of the #include <asio.hpp> right without this
 # TODO: find the real cause of asio/boost wanting pthreads

m4macros/ax_boost_for_bind10.m4

@@ -0,0 +1,88 @@
+dnl @synopsis AX_BOOST_FOR_BIND10
+dnl
+dnl Test for the Boost C++ header files intended to be used within BIND 10
+dnl
+dnl If no path to the installed boost header files is given via the
+dnl --with-boost-include option,  the macro searchs under
+dnl /usr/local /usr/pkg /opt /opt/local directories.
+dnl If it cannot detect any workable path for Boost, this macro treats it
+dnl as a fatal error (so it cannot be called if the availability of Boost
+dnl is optional).
+dnl
+dnl This macro also tries to identify some known portability issues, and
+dnl sets corresponding variables so the caller can react to (or ignore,
+dnl depending on other configuration) specific issues appropriately.
+dnl
+dnl This macro calls:
+dnl
+dnl   AC_SUBST(BOOST_INCLUDES)
+dnl
+dnl And possibly sets:
+dnl   CPPFLAGS_BOOST_THREADCONF should be added to CPPFLAGS by caller
+dnl   BOOST_OFFSET_PTR_WOULDFAIL set to yes if offset_ptr would cause build
+dnl                              error; otherwise set to no
+dnl
+
+AC_DEFUN([AX_BOOST_FOR_BIND10], [
+AC_LANG_SAVE
+AC_LANG([C++])
+
+#
+# Configure Boost header path
+#
+# If explicitly specified, use it.
+AC_ARG_WITH([boost-include],
+  AC_HELP_STRING([--with-boost-include=PATH],
+    [specify exact directory for Boost headers]),
+    [boost_include_path="$withval"])
+# If not specified, try some common paths.
+if test -z "$with_boost_include"; then
+	boostdirs="/usr/local /usr/pkg /opt /opt/local"
+	for d in $boostdirs
+	do
+		if test -f $d/include/boost/shared_ptr.hpp; then
+			boost_include_path=$d/include
+			break
+		fi
+	done
+fi
+
+# Check the path with some specific headers.
+CPPFLAGS_SAVED="$CPPFLAGS"
+if test "${boost_include_path}" ; then
+	BOOST_INCLUDES="-I${boost_include_path}"
+	CPPFLAGS="$CPPFLAGS $BOOST_INCLUDES"
+fi
+AC_CHECK_HEADERS([boost/shared_ptr.hpp boost/foreach.hpp boost/interprocess/sync/interprocess_upgradable_mutex.hpp boost/date_time/posix_time/posix_time_types.hpp boost/bind.hpp boost/function.hpp],,
+  AC_MSG_ERROR([Missing required header files.]))
+
+# Detect whether Boost tries to use threads by default, and, if not,
+# make it sure explicitly.  In some systems the automatic detection
+# may depend on preceding header files, and if inconsistency happens
+# it could lead to a critical disruption.
+AC_MSG_CHECKING([whether Boost tries to use threads])
+AC_TRY_COMPILE([
+#include <boost/config.hpp>
+#ifdef BOOST_HAS_THREADS
+#error "boost will use threads"
+#endif],,
+[AC_MSG_RESULT(no)
+ CPPFLAGS_BOOST_THREADCONF="-DBOOST_DISABLE_THREADS=1"],
+[AC_MSG_RESULT(yes)])
+
+# Boost offset_ptr is known to not compile on some platforms, depending on
+# boost version, its local configuration, and compiler.  Detect it.
+AC_MSG_CHECKING([Boost offset_ptr compiles])
+AC_TRY_COMPILE([
+#include <boost/interprocess/offset_ptr.hpp>
+],,
+[AC_MSG_RESULT(yes)
+ BOOST_OFFSET_PTR_WOULDFAIL=no],
+[AC_MSG_RESULT(no)
+ BOOST_OFFSET_PTR_WOULDFAIL=yes])
+
+AC_SUBST(BOOST_INCLUDES)
+
+CPPFLAGS="$CPPFLAGS_SAVED"
+AC_LANG_RESTORE
+])dnl AX_BOOST_FOR_BIND10