c++ - building program with make and automatic dependencies -

i have written simple c++ program, , first time want compile , link using makefile. challenge want make makefile, lists dependencies itself. following this tutorial. program consist of main.cpp, ext1.cpp , ext1.h. following tutorial, have following makefile

vpath    = src include  cppflags = -o include  cc = gcc  sources  = main.cpp \        ext1.cpp    -include $(subst .c,.d,$(sources))    %.d: %.c     $(cc) -m $(cppflags) $< > $@.$$$$;                      \     sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@;     \     rm -f $@.$$$$ 

when run message: make: *** no targets specified , no makefile found. stop. not clear me missing in case?

you trying @ once.

step 1. first makefile should build executable without attempting automatic dependency detection.

vpath = include src cppflags += -iinclude cc = gcc  exec: main.o ext1.o     $(cc) $^ -o $@  %.o: %.cc     $(cc) -c $(cppflags) $< -o $@  main.o ext1.o: ext1.h 

step 2. once works perfectly, can put header dependencies in separate files:

makefile:

vpath = include src cppflags += -iinclude cc = gcc  exec: main.o ext1.o     $(cc) $^ -o $@  %.o: %.cc     $(cc) -c $(cppflags) $< -o $@  -include *.d 

main.d:

main.o : ext1.h 

ext1.d:

ext1.o: ext1.h 

step 3. once that works perfectly, can generate dependency files automatically:

vpath = include src cppflags += -iinclude cc = gcc  exec: main.o ext1.o     $(cc) $^ -o $@  %.o: %.cc     $(cc) -c -mmd $(cppflags) $< -o $@  -include *.d