Autotools not linking GLFW properly

Question

I'm trying to set up a project using autotools. I'm going to need the executable to be linked against GLFW, but I can't get it to work.

configure.ac:

AC_INIT([Test], [0.1], [test@example.com])
AM_INIT_AUTOMAKE([-Wall -Werror foreign])
AC_PROG_CXX
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_FILES([
                 Makefile
                 src/Makefile
                 ])
AC_OUTPUT
PKG_CHECK_MODULES([glfw3],[glfw3])

Makefile.am:

SUBDIRS = src

src/Makefile.am:

bin_PROGRAMS = testapp
testapp_SOURCES = main.cpp
testapp_CFLAGS = ${glfw3_CFLAGS}
testapp_LDADD = ${glfw3_LIBS}

When I run ./configure, everything works out just fine. glfw3 is found as expexted. However, when I try to compile the code using make, it appears that the executable isn't linked properly.

make  all-recursive
make[1]: Entering directory '/home/dennis/Utveckling/testapp'
Making all in src
make[2]: Entering directory '/home/dennis/Utveckling/testapp/src'
g++ -DHAVE_CONFIG_H -I. -I..     -g -O2 -MT main.o -MD -MP -MF .deps/main.Tpo -c -o main.o main.cpp
mv -f .deps/main.Tpo .deps/main.Po
g++  -g -O2   -o testapp main.o  
main.o: In function `main':
/home/dennis/Utveckling/testapp/src/main.cpp:6: undefined reference to `glfwInit'
/home/dennis/Utveckling/testapp/src/main.cpp:7: undefined reference to `glfwCreateWindow'
/home/dennis/Utveckling/testapp/src/main.cpp:8: undefined reference to `glfwMakeContextCurrent'
/home/dennis/Utveckling/testapp/src/main.cpp:12: undefined reference to `glClear'
/home/dennis/Utveckling/testapp/src/main.cpp:13: undefined reference to `glfwSwapBuffers'
/home/dennis/Utveckling/testapp/src/main.cpp:14: undefined reference to `glfwPollEvents'
/home/dennis/Utveckling/testapp/src/main.cpp:10: undefined reference to `glfwWindowShouldClose'
collect2: error: ld returned 1 exit status
Makefile:333: recipe for target 'testapp' failed
make[2]: *** [testapp] Error 1
make[2]: Leaving directory '/home/dennis/Utveckling/testapp/src'
Makefile:353: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/dennis/Utveckling/testapp'
Makefile:294: recipe for target 'all' failed
make: *** [all] Error 2

What am I doing wrong? The code is a copy and paste from http://www.glfw.org/documentation.html

Answer 1

You should move PKG_CHECK_MODULE before AC_OUTPUT . The configure.ac is executed top-down, so you're subsituting the values into your Makefile.in before you calculate it.

Also a note out of style, in Makefile.am you should use $() form rather than ${} .