Link libcrash conditionally.

Makefile

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # Makefile for metrics utilities -- library, client and daemon
 #
 
 CCONFIG = $(shell $(PKG_CONFIG) --cflags dbus-1 glib-2.0 dbus-glib-1)
 LDCONFIG = $(shell $(PKG_CONFIG) --libs dbus-1 glib-2.0 gthread-2.0 dbus-glib-1)
 
 CXXFLAGS += -Wall -Werror -fPIC -fno-exceptions $(CCONFIG)
 
 CLIENT = metrics_client
 DAEMON = metrics_daemon
 DAEMON_TEST = metrics_daemon_test
 LIB = libmetrics.a
 SHAREDLIB = libmetrics.so
 LIB_TEST = metrics_library_test
 COUNTER_TEST = counter_test
 
+LCRASH ?= -lcrash
+
 TESTCOUNTER_OBJS = \
         counter.o \
         counter_test.o
 CLIENT_OBJS = \
         metrics_client.o
 DAEMON_OBJS = \
         counter.o \
         metrics_daemon.o \
         metrics_daemon_main.o
 TESTDAEMON_OBJS = \
@@ skipping 15 matching lines @@
 
 tests: $(COUNTER_TEST) $(DAEMON_TEST) $(LIB_TEST)
 
 $(CLIENT): $(CLIENT_OBJS) $(SHAREDLIB)
         $(CXX) $(LDFLAGS) $^ -o $@
 
 $(COUNTER_TEST): $(TESTCOUNTER_OBJS)
         $(CXX) -o $@ $^ $(TESTCOUNTER_LIBS)
 
 $(DAEMON): $(DAEMON_OBJS) $(SHAREDLIB)
-        $(CXX) -o $@ $^ $(DAEMON_LDFLAGS) -lcrash
+        $(CXX) -o $@ $^ $(DAEMON_LDFLAGS) $(LCRASH)
 
 $(DAEMON_TEST): $(TESTDAEMON_OBJS)
         $(CXX) -o $@ $^ $(DAEMON_LDFLAGS) $(TESTDAEMON_LIBS)
 
 $(LIB): $(LIB_OBJS)
         $(AR) rcs $@ $^
 
 $(SHAREDLIB): $(LIB_OBJS)
         $(CXX) $(LDFLAGS) -shared $^ -o $@
 
 $(LIB_TEST): $(TESTLIB_OBJS) $(SHAREDLIB)
         $(CXX) -o $@ $^ $(LDFLAGS) $(TESTLIB_LIBS)
 
 %.o: %.cc
         $(CXX) $(CXXFLAGS) -c $< -o $@
 
 clean:
         rm -f $(CLIENT) $(DAEMON) $(LIB) $(SHAREDLIB) *.o
         rm -f $(COUNTER_TEST) $(DAEMON_TEST) $(LIB_TEST)