Build targets in make file

[thmm]

I try to create a make file for different targets.
I get the the followinfg warnings.
makefile:15: warning: overriding recipe for target 'main.o'
makefile:9: warning: ignoring old recipe for target 'main.o'
clang -c main.c
clang main.o -o main.exe
Compilation finished successfully.
How do I fix the warnings

CC=clang
RELEASE_FLAGS= -Wall -Wextra -Wshadow -Wpedantic -Werror -std=c99  -DNDEBUG -O3
DEBUG_FLAGS = -Wall -Wextra -Wshadow -Wpedantic -Werror -std=c99  -g 

release: main.o 
	$(CC) $(RELEASE_FLAGS) main.o -o main.exe
	
main.o: main.c
	$(CC) $(RELEASE_FLAGS)  -c main.c
	
debug: main.o 
	$(CC)  $(DEBUG_FLAGS)  main.o -o main.exe
	
main.o: main.c
	$(CC) $(DEBUG_FLAGS) -c main.c

	
clean:
	del *.o del output.exe del *.exp del *.lib del *.pdb
	

[salem c]

Don't you have do type make debug or make release ?

[thmm]

Yes I tried both, but get the same warnings.

make release
makefile:15: warning: overriding recipe for target 'main.o'
makefile:9: warning: ignoring old recipe for target 'main.o'
clang -Wall -Wextra -Wshadow -Wpedantic -Werror -std=c99  -DNDEBUG -O3 main.o -o main.exe

C:\Users\Vedanta Centre\Desktop\Make Demo>
make debug
makefile:15: warning: overriding recipe for target 'main.o'
makefile:9: warning: ignoring old recipe for target 'main.o'
clang  -Wall -Wextra -Wshadow -Wpedantic -Werror -std=c99  -g   main.o -o main.exe

[z05DSL3A]

I think you want something like...

CC:= clang
CCFLAGS:= -Wall -Wextra -Wshadow -Wpedantic -Werror -std=c99 

all: main.o
	$(CC) $(CCFLAGS) main.o -o main.exe

main.o: main.c
	$(CC) $(CCFLAGS)  -c main.c

.PHONY: all debug release clean

debug: CCFLAGS += -g
debug: all

release: CCFLAGS += -DNDEBUG -O3
release: all

clean:
	del *.o del output.exe del *.exp del *.lib del *.pdb

[dutch]

I came up with something similar but using implicit rules. The only problem is that you need to remember to make clean before you make release (or just make) or make debug since it considers either one to already be built since the output files have the same name.

CC := clang
CFLAGS := -std=c99 -Wall -Wextra -Wpedantic -Wshadow -Werror
RELEASE_FLAGS := -DNDEBUG -O3
DEBUG_FLAGS := -g 

.PHONY: release debug clean

release: CFLAGS += $(RELEASE_FLAGS)
release: main.exe

debug: CFLAGS += $(DEBUG_FLAGS)
debug: main.exe

clean:
	-rm -f *.o main.exe

Shouldn't -Wshadow be enabled by -Wpedantic? I'm not sure so I left it in.
I also used rm instead of del, which I know nothing about since I use linux.

[thmm]

@Grey Wolf,
thanks, it's working.

@dutch,
it doesn't work.

make clean
del *.o main.exe
Could Not Find *.o

C:\Users\Vedanta Centre\Desktop\Make Demo>
make release
make: *** No rule to make target 'main.exe', needed by 'release'.  Stop.

make debug
make: *** No rule to make target 'main.exe', needed by 'debug'.  Stop.

C:\Users\Vedanta Centre\Desktop\Make Demo>

[dutch]

I guess you need an explicit rule on windows for main.exe.

CC := clang
CFLAGS := -std=c99 -Wall -Wextra -Wpedantic -Wshadow -Werror
RELEASE_FLAGS := -DNDEBUG -O3
DEBUG_FLAGS := -g 

.PHONY: release debug clean

release: CFLAGS += $(RELEASE_FLAGS)
release: main.exe

debug: CFLAGS += $(DEBUG_FLAGS)
debug: main.exe

main.exe: main.o
	$(CC) $(CFLAGS) -o $@ $<

clean:
	rm -f *.o main.exe

And remember that you can just say make to build the first target (release, in this case, since targets starting with a dot don't count).

A variable for main.exe might be a good idea:

CC := clang
CFLAGS := -std=c99 -Wall -Wextra -Wpedantic -Wshadow -Werror
RELEASE_FLAGS := -DNDEBUG -O3
DEBUG_FLAGS := -g 
src := main.exe
obj := $(src:.exe=.o)

.PHONY: release debug clean

release: CFLAGS += $(RELEASE_FLAGS)
release: $(src)

debug: CFLAGS += $(DEBUG_FLAGS)
debug: $(src)

$(src): $(obj)
	$(CC) $(CFLAGS) -o $@ $<

clean:
	rm -f $(obj) $(src)

[thmm]

Thanks @dutch,
it's working now.