Makefile issue with compiling a C++ program
- by Steve
I recently got MySQL compiled and working on Cygwin, and got a simple test example from online to verify that it worked. The test example compiled and ran successfully.
However, when incorporating MySQL in a hobby project of mine it isn't compiling which I believe is due to how the Makefile is setup, I have no experience with Makefiles and after reading tutorials about them, I have a better grasp but still can't get it working correctly.
When I try and compile my hobby project I recieve errors such as:
Obj/Database.o:Database.cpp:(.text+0x492): undefined reference to `_mysql_insert_id'
Obj/Database.o:Database.cpp:(.text+0x4c1): undefined reference to `_mysql_affected_rows'
collect2: ld returned 1 exit status
make[1]: *** [build] Error 1
make: *** [all] Error 2
Here is my Makefile, it worked with compiling and building the source before I attempted to put in MySQL support into the project. The LIBMYSQL paths are correct, verified by 'mysql_config'.
COMPILER = g++
WARNING1 = -Wall -Werror -Wformat-security -Winline -Wshadow -Wpointer-arith
WARNING2 = -Wcast-align -Wcast-qual -Wredundant-decls
LIBMYSQL = -I/usr/local/include/mysql -L/usr/local/lib/mysql -lmysqlclient
DEBUGGER = -g3
OPTIMISE = -O
C_FLAGS = $(OPTIMISE) $(DEBUGGER) $(WARNING1) $(WARNING2) -export-dynamic $(LIBMYSQL)
L_FLAGS = -lz -lm -lpthread -lcrypt $(LIBMYSQL)
OBJ_DIR = Obj/
SRC_DIR = Source/
MUD_EXE = project
MUD_DIR = TestP/
LOG_DIR = $(MUD_DIR)Files/Logs/
ECHOCMD = echo -e
L_GREEN = \e[1;32m
L_WHITE = \e[1;37m
L_BLUE = \e[1;34m
L_RED = \e[1;31m
L_NRM = \e[0;00m
DATE = `date +%d-%m-%Y`
FILES = $(wildcard $(SRC_DIR)*.cpp)
C_FILES = $(sort $(FILES))
O_FILES = $(patsubst $(SRC_DIR)%.cpp, $(OBJ_DIR)%.o, $(C_FILES))
all:
@$(ECHOCMD) " Compiling $(L_RED)$(MUD_EXE)$(L_NRM).";
@$(MAKE) -s build
build: $(O_FILES)
@rm -f $(MUD_EXE)
$(COMPILER) -o $(MUD_EXE) $(L_FLAGS) $(O_FILES)
@echo " Finished Compiling $(MUD_EXE).";
@chmod g+w $(MUD_EXE)
@chmod a+x $(MUD_EXE)
@chmod g+w $(O_FILES)
$(OBJ_DIR)%.o: $(SRC_DIR)%.cpp
@echo " Compiling $@";
$(COMPILER) -c $(C_FLAGS) $< -o $@
.cpp.o:
$(COMPILER) -c $(C_FLAGS) $<
clean:
@echo " Complete compile on $(MUD_EXE).";
@rm -f $(OBJ_DIR)*.o $(MUD_EXE)
@$(MAKE) -s build
I like the functionality of the Makefile, instead of spitting out all the arguments etc, it just spits out the "Compiling [Filename]" etc.
If I add -c to the L_FLAGS then it compiles (I think) but instead spits out stuff like:
g++: Obj/Database.o: linker input file unused because linking not done
After a full day of trying and research on google, I'm no closer to solving my problem, so I come to you guys to see if you can explain to me why all this is happening and if possible, steps to solve.
Regards,
Steve
