No reference to glib functions

December 1, 2021

everyone.
I’m working on ubuntu, developing this application using the glib resources, I wrote a makefile like this:

INCLUDES= -I ./headers
FLAGS= -g

PKGCONFIGCFLAGS= `pkg-config --cflags qmi-glib` `pkg-config --cflags gio-2.0` `pkg-config --cflags gobject-2.0` `pkg-config --cflags glib-2.0` `pkg-config --cflags gmodule-no-export-2.0` `pkg-config --cflags gmodule-2.0`

PKGCONFIGLIBS= `pkg-config --libs qmi-glib` `pkg-config --libs gio-2.0` `pkg-config --libs glib-2.0` `pkg-config --libs gobject-2.0` `pkg-config --libs gmodule-no-export-2.0` `pkg-config --libs gmodule-2.0`

CC=gcc

OBJECTS=./build/qmi_test.o

all: ${OBJECTS}
  $(CC) ${FLAGS} ${INCLUDES} ./sources/main.c ${OBJECTS} -o ./bin/main
./build/qmi_test.o:./sources/qmi_test.c
  $(CC) ${FLAGS} ${INCLUDES}  ${PKGCONFIGCFLAGS} ./sources/qmi_test.c ${PKGCONFIGLIBS} -lm -o ./build/qmi_test.o

As you may notice, I inserted every glib related resource I found because I keep receiving this in return:

/usr/bin/ld: ./build/qmi_test.o: in function `g_autoptr_cleanup_generic_gfree':
/usr/include/glib-2.0/glib/glib-autocleanups.h:28: undefined reference to `g_free'
/usr/bin/ld: ./build/qmi_test.o: in function `qmi_test1':
/home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:24: undefined reference to `g_file_new_for_path'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:25: undefined reference to `g_main_loop_new'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:26: undefined reference to `g_cancellable_new'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:29: undefined reference to `g_main_loop_run'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:31: undefined reference to `g_object_unref'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:32: undefined reference to `g_main_loop_unref'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:33: undefined reference to `g_object_unref'
/usr/bin/ld: ./build/qmi_test.o: in function `Device_Create_Start':
/home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:42: undefined reference to `g_file_get_path'
/usr/bin/ld: /home/myUser/Documents/quectel_eg25-g/./sources/qmi_test.c:45: undefined reference to `qmi_device_new'
collect2: error: ld returned 1 exit status
make: *** [Makefile:13: all] Error 1

I read in that the order of ellements when calling gcc does matter. But I’m trying to follow the order of elements as shown here:
glib compiling

Any help or recommendation is welcome.

>Solution :

You need to add the library flags (PKGCONFIGLIBS) to the link step and not the compile step:

all: ${OBJECTS}
  $(CC) ${FLAGS} ${INCLUDES} -lm ./sources/main.c ${OBJECTS} ${PKGCONFIGLIBS} -lm -o ./bin/main
./build/qmi_test.o:./sources/qmi_test.c
  $(CC) ${FLAGS} ${INCLUDES}  ${PKGCONFIGCFLAGS} ./sources/qmi_test.c  -o ./build/qmi_test.o