Makefile problem when adding dependencies

[zahid990170]

Hi,

I am a beginner in writing makefiles. I am having some problem compiling an application using Makefile.

I have two directories, that are at the same level.
1: TEST, in which resides the application that I have written,
2: PROJECT_DIRECTORY, is an existing project with a nested directory structure.

my Makefile resides in TEST.

my application needs to access some functions defined in a file called M_Example.h. M_Example.c and M_Example.h both reside in

PROJECT_DIRECTORY/some_dir_1/some_dir_2/some_dir_3/some_dir_4

Now, independently of TEST, I can compile PROJECT_DIRECTORY successfully and the compilation process generates .o files and .a files. My understanding is that these are the libraries at each level and could be used as such in the Makefile. For example, after compilation, I have

 M_Example.o

at the location

PROJECT_DIRECTORY/some_dir_1/some_dir_2/some_dir_3/some_dir_4

So, here is how my makefile looks

APP_PATH=./
INCLUDE_PATH=./
PROJECT_CORE_PATH=../PROJECT_DIRECTORY/some_dir_1/some_dir_2/some_dir_3/some_dir_4

PROJECT_INCLUDE_PATH = $(PROJECT_CORE_PATH)

WARNINGS = -Wall

APP_SOURCES=$(wildcard $(APP_PATH)/*.c)
APP_HEADERS=$(wildcard $(APP_PATH)/*.h)
PROJECT_LIBS=$(wildcard $(PROJECT_CORE_PATH)/*.o)
PROJECT_HEADERS=$(wildcard $(PROJECT_CORE_PATH)/*.h)

vpath %.c $(APP_SOURCES)
vpath %.h $(APP_HEADERS) $(PROJECT_HEADERS)
vpath %.o $(PROJECT_LIBS)


all : hello

hello : my_string_help.o 

my_string_help.o : my_string_help.c $(APP_HEADERS) $(PROJECT_HEADERS) $(PROJECT_LIBS)
	gcc -c my_string_help.c 

clean:
	rm -f my_string_help.o hello

This is very basic file, my_string_help.c resides in folder TEST, and uses a function from PROJECT_DIRECTORY. I just need to make sure that it can link without errors, but I get the following error when I run "make".


gcc -c my_string_help.c
my_string_help.c:2:22: error: M_Example.h: No such file or directory
make: *** [my_string_help.o] Error 1

thanks,

[Salem]

Random tutorial.
Makefile Tutorial

Setting vpath only enables the makefile to determine the location of dependencies.

You also need to typically set CFLAGS with appropriate -I paths to also tell the compiler where to find header files.

[zahid990170]

thanks Salem, that helped.
the problem is solved.