Makefile for OpenGL with glad on Linux - linux

Question

I want to use glad in my OpenGL project but I am not quite sure how to create the Makefile for it. I downladed glad from the webservice and moved the directories from include/ (glad/ and KHR/) to /usr/include/ (Now emacs sees the library) and the glad.c file to the root of my project (which at the moment contatns only a demo source.cpp file).
I have this Makefile:
UNAME_S := $(shell uname -s)
ifeq ($(UNAME_S), Linux)
COMPILER = g++
FLAGS = -std=c++1y -pedantic -Wall
GL_FLAGS = -lGL -lglfw
endif
ifeq ($(UNAME_S), Darwin)
COMPILER = clang++
FLAGS = -std=c++1y -stdlib=libc++ -pedantic -Wall
GL_FLAGS = -lGLEW -framework OpenGL -lm
endif
FILES = $(wildcard *.cpp)
APP_NAME = opengl-app
all: main
main: $(FILES)
$(COMPILER) $(FLAGS) $(FILES) glad.c -o $(APP_NAME) $(GL_FLAGS)
.PHONY: clean run
clean:
rm opengl-app
run: opengl-app
./opengl-app
This when executed gives these errors:
/usr/bin/ld: /tmp/cc0DUjDZ.o: undefined reference to symbol 'dlclose##GLIBC_2.2.5'
/usr/lib/libdl.so.2: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Any help with the makefile will be greatly appreciated.

Answer 1

As mentioned in the comments by #G.M. glad makes use of dlopen/dlclose, methods used to load shared objects in Linux.
The Makefile should add the link flag to use libdl.so. The final result should be something like this:
UNAME_S := $(shell uname -s)
ifeq ($(UNAME_S), Linux)
COMPILER = g++
FLAGS = -std=c++1y -pedantic -Wall
GL_FLAGS = -lGL -lglfw
endif
ifeq ($(UNAME_S), Darwin)
COMPILER = clang++
FLAGS = -std=c++1y -stdlib=libc++ -pedantic -Wall
GL_FLAGS = -lGLEW -framework OpenGL -lm
GLAD_FLAGS = -ldl
endif
FILES = $(wildcard *.cpp)
APP_NAME = opengl-app
all: main
main: $(FILES)
$(COMPILER) $(FLAGS) $(FILES) glad.c -o $(APP_NAME) $(GL_FLAGS) $(GLAD_FLAGS)
.PHONY: clean run
clean:
rm opengl-app
run: opengl-app
./opengl-app