gcc won't compile SDL C Program (undefined reference to SDL functions)

Question

I recently moved to linux and i\'m having an issue with compiling SDL C programs using gcc.

The command i\'m using:

gcc `sdl-config --cflags --libs`          


        

Answer 1

Thanks a lot for the advices ! This helped me to solve an old mystery about SDL symbols never found under Linux :-) As wroten in the comments, the order of gcc line is essential. The makefile was not well written and this was causing the breakage you mentionned.

As summary, use : gcc ( flags ) -o name ( include et linking options)

Last but not least, under x86_64, use gdb64, instead of gdb ( was the next headhache ;-)

As example, a little Makefile I wrote myself (ok, not that good, but works)

# Makefile pour le contrôle du robot Arduino 
# Controle Robot
# Sauf mention contraire, tout est place sous Licence GPL V2
# Historique : 
# Etienne HAMON / création du makefile initial (d'après cours IFT1), Novembre 2014
#
# Corrections du Makefile : Eric Bachard décembre 2014 

CC = gcc
C_STANDARD = -std=c99
INCLUDE_DIR = inc -I/usr/include/SDL
SOURCES_DIR = sources
BUILD_DIR = build
APPLICATION_NAME = Controle
FILENAME = ${BUILD_DIR}/${APPLICATION_NAME}
CFLAGS = -Wall -ansi ${C_STANDARD}
LDFLAGS = -lSDL $(sdl-config --static-libs) -lm
DEBUG_SUFFIX = _debug
CFLAGS_DEBUG = -v -gdwarf-2 -DDEBUG
OBJS = ${SOURCES_DIR}/*.c

all : ${FILENAME} ${FILENAME}${DEBUG_SUFFIX}

${FILENAME}: ${OBJS}
    ${CC} ${CFLAGS} -o $@  $^ -I${INCLUDE_DIR} ${LDFLAGS} 

${FILENAME}${DEBUG_SUFFIX}: ${OBJS}
    ${CC} ${CFLAGS} ${CFLAGS_DEBUG} -o $@ $^ -I${INCLUDE_DIR} ${LDFLAGS} 

clean:
    ${RM} *.o ${FILENAME} ${FILENAME}${DEBUG_SUFFIX}
    ${RM} -rf ${BUILD_DIR}/*.dSYM