GCC: Undefined reference (Makefile issue) - c

Question

Trying to compile these files with gcc under Makefile rules. Running gcc / make on cygwin.
Here's the makefile:
CC = gcc
CFLAGS = -g -O2 -Wall -std=c99
OBJECTS = simulation.o element.o
simulation.exe : $(OBJECTS)
$(CC) $(CFLAGS) -o simulation.exe $(OBJECTS)
simulation.o : file_priorite.o element.o
$(CC) $(CFLAGS) -c simulation.c
file_priorite.o: file_priorite.h element.o
$(CC) $(CFLAGS) -c file_priorite.c
element.o : element.h
$(CC) $(CFLAGS) -c element.c
clean:
rm -f *.o simulation.exe
And getting these errors:
CLEAN SUCCESSFUL (total time: 52ms)
gcc -g -O2 -Wall -std=c99 -c element.c
gcc -g -O2 -Wall -std=c99 -c simulation.c
gcc -g -O2 -Wall -std=c99 -o simulation.exe simulation.o element.o
simulation.o: In function `main':
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:11: undefined reference to `construire'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:11:(.text.startup+0x17): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `construire'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:20: undefined reference to `ajouter_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:20:(.text.startup+0x69): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `ajouter_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:23: undefined reference to `consommer_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:23:(.text.startup+0x76): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `consommer_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:23: undefined reference to `consommer_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:23:(.text.startup+0x86): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `consommer_element'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:25: undefined reference to `obtenir_taille'
/cygdrive/d/Dropbox/UQAM AUTOMNE 2014/INF7330/lab10/lab10/simulation.c:25:(.text.startup+0x96): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `obtenir_taille'
collect2: error: ld returned 1 exit status
Makefile:6: recipe for target 'simulation.exe' failed
make: *** [simulation.exe] Error 1
The problematic functions are all implemented in file_priorite.c.
Any idea?

Answer 1

You need to have
OBJECTS = simulation.o element.o file_priorite.o

Answer 2

Notice that your build log doesn't include file_priorite in any form - that means you're not building/linking against it. Add file_priorite.o to your OBJECTS line.