Example of compiling a C++ application and linking against providers compiled as C shared objects.

demo.cpp

/*
 * Copyright (C) 2009  Pierre-Marc Fournier
 * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; version 2.1 of
 * the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <arpa/inet.h>
#include <stdlib.h>

#define TRACEPOINT_DEFINE
#define TRACEPOINT_PROBE_DYNAMIC_LINKAGE
#include "ust_tests_demo.h"
#include "ust_tests_demo2.h"
#include "ust_tests_demo3.h"

class CPPTest
{
public:
	CPPTest() { somethingToCheckItBuilds = 42; }
	void test() { printf("Hello from CPP application!\n"); }
private:
	int somethingToCheckItBuilds;
};

int main(int argc, char **argv)
{
	int i, netint;
	long values[] = { 1, 2, 3 };
	char text[10] = "test";
	double dbl = 2.0;
	float flt = 2222.0;
	int delay = 0;

	CPPTest it_works;
	it_works.test();

	if (argc == 2)
		delay = atoi(argv[1]);

	fprintf(stderr, "Demo program starting.\n");

	sleep(delay);

	fprintf(stderr, "Tracing... ");
	tracepoint(ust_tests_demo, starting, 123);
	for (i = 0; i < 5; i++) {
		netint = htonl(i);
		tracepoint(ust_tests_demo2, loop, i, netint, values,
			   text, strlen(text), dbl, flt);
	}
	tracepoint(ust_tests_demo, done, 456);
	tracepoint(ust_tests_demo3, done, 42);
	fprintf(stderr, " done.\n");
	return 0;
}

Makefile

# Copyright (C) 2013  Jérémie Galarneau <jeremie.galarneau@efficios.com>
#
# THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
# OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
#
# Permission is hereby granted to use or copy this program for any
# purpose, provided the above notices are retained on all copies.
# Permission to modify the code and to distribute modified code is
# granted, provided the above notices are retained, and a notice that
# the code was modified is included with the above copyright notice.

# This Makefile is not using automake so that users may see how to build
# a program with tracepoint provider probes as stand-alone shared objects.

CC = gcc
LIBS = -ldl	# On Linux
#LIBS = -lc	# On BSD
LOCAL_CPPFLAGS += -I.

# Only necessary when building from the source tree and lttng-ust is not
# installed
ifdef BUILD_EXAMPLES_FROM_TREE
LOCAL_CPPFLAGS += -I../../../include/
LIBLTTNG_UST_PATH = ../../../liblttng-ust/.libs/
override LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'

# Third-party Makefiles have to define these targets to integrate with an
# automake project
EMPTY_AUTOMAKE_TARGETS = distdir install install-data install-exec uninstall \
	install-dvi install-html install-info install-ps install-pdf \
	installdirs check installcheck mostlyclean distclean maintainer-clean \
	dvi html pdf ps info tags ctags
.PHONY: $(EMPTY_AUTOMAKE_TARGETS)
$(EMPTY_AUTOMAKE_TARGETS):
endif

all: demo lttng-ust-provider-ust-tests-demo.so lttng-ust-provider-ust-tests-demo3.so

tp.o: tp.c ust_tests_demo.h
	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<

tp2.o: tp2.c ust_tests_demo2.h
	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<

lttng-ust-provider-ust-tests-demo.so: tp.o tp2.o
	$(CC) -shared -o $@ $(LDFLAGS) -llttng-ust $^

tp3.o: tp3.c ust_tests_demo3.h
	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<

lttng-ust-provider-ust-tests-demo3.so: tp3.o
	$(CC) -shared -o $@ $(LDFLAGS) -llttng-ust $^

demo.o: demo.cpp
	g++ $(CPPFLAGS) $(CFLAGS) -c -o $@ $<

demo: demo.o lttng-ust-provider-ust-tests-demo3.so
	g++ -o $@ $^ -L. $(LIBS) -Wl,-rpath=.

.PHONY: clean
clean:
	rm -f *.o *.so demo