gcc                       -lpthread -lm -g      -o calculPi.exe approx.o producteur.o sequentialApproximation.o main.o
approx.o: In function `init':
/home/moons/Etudes/ProgConc/CalculPi/approx.c:14: undefined reference to `indice_prod'
/home/moons/Etudes/ProgConc/CalculPi/approx.c:15: undefined reference to `indice_cons'
/home/moons/Etudes/ProgConc/CalculPi/approx.c:16: undefined reference to `production'
collect2: ld returned 1 exit status
make: *** [calculPi.exe] Erreur 1