Add BOOST_LOG and BOOST_LOG_SETUP.

Based on a contribution from Bernd Prager <bernd at prager.ws>.

THANKS

@@ -8,6 +8,7 @@ Alexandre Rostovtsev
 Anthony Mallet
 Aurimas Černius
 Bastien Nocera
+Bernd Prager
 Daniel Herring
 Giles Hall
 Hubert Figuière

build-aux/boost.m4

@@ -588,6 +588,29 @@ BOOST_DEFUN([Lambda],
 [BOOST_FIND_HEADER([boost/lambda/lambda.hpp])])
 
 
+# BOOST_LOG([PREFERRED-RT-OPT])
+# -----------------------------
+# Look for Boost.Log For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Log],
+[BOOST_FIND_LIB([log], [$1],
+    [boost/log/core/core.hpp],
+    [boost::log::attribute a; a.get_value();])
+])# BOOST_LOG
+
+
+# BOOST_LOG_SETUP([PREFERRED-RT-OPT])
+# -----------------------------------
+# Look for Boost.Log For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Log_Setup],
+[AC_REQUIRE([BOOST_LOG])dnl
+BOOST_FIND_LIB([log_setup], [$1],
+    [boost/log/utility/init/from_settings.hpp],
+    [boost::log::basic_settings<char> bs; bs.empty();])
+])# BOOST_LOG_SETUP
+
+
 # BOOST_MATH()
 # ------------
 # Look for Boost.Math

tests/testsuite.at

@@ -286,6 +286,8 @@ AT_CHECK_MACRO_CROSS([BOOST_FILESYSTEM], [lib])
 AT_CHECK_MACRO([BOOST_GRAPH], [lib])
 AT_CHECK_MACRO([BOOST_IOSTREAMS], [lib])
 AT_CHECK_MACRO([BOOST_IOSTREAMS (static)], [lib], [BOOST_IOSTREAMS([s])])
+AT_CHECK_MACRO([BOOST_LOG], [lib])
+AT_CHECK_MACRO([BOOST_LOG_SETUP], [lib])
 AT_CHECK_MACRO([BOOST_PROGRAM_OPTIONS], [lib])
 AT_CHECK_MACRO([BOOST_PYTHON], [lib])
 AT_CHECK_MACRO([BOOST_PYTHON (static)], [lib], [BOOST_PYTHON([s])])