Makefile questions

[Stewbond]

Trying makefiles for the first time (used to VS). I have a few questions:

1. All files (src, include [for entry points], bin and intermediate) are in the same directory. How can I specify paths for each one?

2. Is there a way to automatically make header dependencies for .o targets?
If I add #include "dictionary.hpp" in synthesizer.hpp, do I have to go back and change my makefile?

3. I've been reading about implicit rules here: http://www.gnu.org/software/make/manual/make.html#Implicit-Rules. I like the -Wall option, how do I include that in an implicit rule so that I can replace

synthesizer.o : synthesizer.cpp synthesizer.hpp
	$(CC) $(CFLAGS) synthesizer.cpp

with

synthesizer.o : synthesizer.hpp

This is my current makefile:

CC = g++
CFLAGS = -c -Wall
objects = synthesizer.o \
          dictionary.o \
          vtest.o

.DEFAULT : all

all : vtest

vtest : $(objects) 
	$(CC) $(objects) -o vtest

synthesizer.o : synthesizer.cpp synthesizer.hpp
	$(CC) $(CFLAGS) synthesizer.cpp

dictionary.o : dictionary.cpp dictionary.hpp
	$(CC) $(CFLAGS) dictionary.cpp

vtest.o : vtest.cpp dictionary.hpp
	$(CC) $(CFLAGS) vtest.cpp

.PHONY : clean
clean:
	-rm vtest *.o

[ne555]

http://users.softlab.ece.ntua.gr/~ttsiod/makefile.html

> How can I specify paths for each one?
For headers, use the INCLUDEFLAGS, by instance -Iheader
note how it has different directories for binary, object files, dependencies, in debug and release configuration.

> Is there a way to automatically make header dependencies for .o targets?
The header dependencies are generated by invoking g++ with the -MM -MP flags

> I like the -Wall option, how do I include that in an implicit rule
CFLAGS are flags for compiling C code
CXXFLAGS are flags for compiling C++ code

[Stewbond]

Ah, so CFLAGS is actually a reserved keyword in make that is implicitly added to the compiler options?

I'm trying to find the INCLUDEFLAGS for the object files, but $man g++ is massive!

I found -MM in there. That looks perfect for what you mentioned.

[Stewbond]

Hmm after adding -MM, the build seems to fail. Before it failed, figured out how to get the output directory in there though. (make is still built from the src folder though).
Here is the makefile/Output

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

# objects objects = synthesizer.o \ dictionary.o \ vtest.o # paths (to integrate) #SRC = src OUT = ../bin #INC = src #INT = int # compile options CXX = g++ CXXFLAGS = -c -Wall -MM .DEFAULT : all all : vtest vtest : $(objects) $(CXX) $(objects) -o $(OUT)/vtest # intermediate files synthesizer.o : synthesizer.cpp $(CXX) $(CXXFLAGS) synthesizer.cpp dictionary.o : dictionary.cpp $(CXX) $(CXXFLAGS) dictionary.cpp vtest.o : vtest.cpp $(CXX) $(CXXFLAGS) vtest.cpp #cleanup .PHONY : clean clean: -rm $(OUT)/vtest *.o

stew@Romulus ~/SVN/vsynth/trunk/src $ make g++ -c -Wall -MM synthesizer.cpp synthesizer.o: synthesizer.cpp synthesizer.hpp vsynth.hpp dictionary.hpp g++ -c -Wall -MM dictionary.cpp dictionary.o: dictionary.cpp dictionary.hpp vsynth.hpp g++ -c -Wall -MM vtest.cpp vtest.o: vtest.cpp dictionary.hpp vsynth.hpp g++ synthesizer.o dictionary.o vtest.o -o ../bin/vtest g++: error: synthesizer.o: No such file or directory g++: error: dictionary.o: No such file or directory g++: error: vtest.o: No such file or directory g++: fatal error: no input files compilation terminated. make: *** [vtest] Error 4

And the output:

[ne555]

> I'm trying to find the INCLUDEFLAGS for the object files
That's just the name given in the example.
CPPFLAGS are the flags for the preprocessor.


> Hmm after adding -MM, the build seems to fail
-MM would not build, it generates dependencies.

$ g++ -c -Wall -MM  synthesizer.cpp
synthesizer.o: synthesizer.cpp synthesizer.hpp vsynth.hpp dictionary.hpp

The idea is to put those dependencies in your makefile
By instance, sending that output to a file and then include it from your makefile.

Take a look at the link

[Stewbond]

That link actually really helped. I've got it working now with proper dependencies and intermediate directories. A lot of the syntax I'm still confused about, but I think I can worry about specific lines when I need to change them.

Thanks,