How can i include header files from another directory using Makefile?

Question

Consider this as my directory structure:

- Main_Dir    
         - Dir1
         |      - Dir2
         |      |     - A.h
         |      |     - B.h
         |      - Dir3
         |            - C.c
         - Makefile

My requirement is that, i have to only use #include <Dir2/Ah> and #include <Dir2/Bh> in the C.c file to include those header files(but not #include <Dir1/Dir2/Ah> and #include <Dir1/Dir2/Bh> ) using Makefile (means that Header files Path can be included in Makefile). Is it Possible to include those headers like that using Makefile ? If anyone Knows on how to do it using Makefile or any suggestions to do it without changing the Directory structure Please let me know.

Answer 1

In your Makefile, it is common to do something like this:

CXXFLAGS += --std=c++17 -I..

and later:

foo.o: foo.cpp
     g++ ${CXXFLAGS} foo.cpp -o foo.o

You can have as many -I arguments as you need.