Link dylib library - xcode

Question

I'm trying to link a dylib to my makefile on Mac, but Clang gives this message:
Undefined symbols for architecture x86_64:
"_zbesj_wrap", referenced from:
sp_bessel::besselJ(double, std::__1::complex<double>) in besselJ.o
"_zbesy_wrap", referenced from:
sp_bessel::besselJ(double, std::__1::complex<double>) in besselJ.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I installed the library in /usr/lib, where I can see libcomplex_bessel.0.6.0.dylib and libcomplex_bessel.dylib.
This is my makefile:
OBJS = main.o besselJ.o
CC = c++
CFLAGS = -std=c++11 -stdlib=libc++
LIBS = -L/usr/lib -lcomplex_bessel
PROGRAM_NAME = test
all: $(PROGRAM_NAME)
$(PROGRAM_NAME): $(OBJS)
$(CC) $(CFLAGS) $(OBJS) -o $#
main.o: main.cpp
$(CC) $(CFLAGS) -c $< -o $#
besselJ.o: besselJ.cpp
$(CC) $(CFLAGS) -c $< -o $# $(LIBS)
After reading other questions, I tried different combinations for -L and -l but nothing worked. Sorry but it's my first time with external libraries...
I changed my makefile to this:
OBJS = main.o besselJ.o
CC = c++
CFLAGS = -std=c++11 -stdlib=libc++
LIBS = -L/usr/lib -lcomplex_bessel
PROGRAM_NAME = test
all: $(PROGRAM_NAME)
$(PROGRAM_NAME): $(OBJS)
$(CC) $(CFLAGS) $(OBJS) -o $# $(LIBS)
main.o: main.cpp
$(CC) $(CFLAGS) -c $< -o $#
besselJ.o: besselJ.cpp
$(CC) $(CFLAGS) -c $< -o $#
but I still have problems, I get this message:
c++ -std=c++11 -stdlib=libc++ main.o besselJ.o -o test -L/usr/lib -lcomplex_bessel
ld: library not found for -lcomplex_bessel
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [test] Error 1
Ok, I think I solved it using xcode-select --install: other users had the same problem with libraries after updating it.

Answer 1

You need to pass libs to linker, not to the compiler:
OBJS = main.o besselJ.o
CC = c++
CFLAGS = -std=c++11 -stdlib=libc++
LIBS = -L/usr/lib -lcomplex_bessel
PROGRAM_NAME = test
all: $(PROGRAM_NAME)
$(PROGRAM_NAME): $(OBJS)
$(CC) $(OBJS) -o $# $(LIBS)
main.o: main.cpp
$(CC) $(CFLAGS) -c $< -o $#
besselJ.o: besselJ.cpp
$(CC) $(CFLAGS) -c $< -o $#