Question

I have a C project that has the following structure

Main/
  Makefile.am
  bin/
  src/
     Makefile.am
     main.c
     SomeLibrarySource/
         SomeFuncs.c
         SomeFuncs.h

The main.c contains the main function that uses functions defined in the SomeFuncs.{h/c} files.

I want to use autotools for this project. I read a couple of resources on autotools. But, I was only able to manage using autotools for a single level project where all source, object and other files reside in the same directory.

Then I got some links that talked about using autotools for deep projects like this one and then I got confused.

Right now I have two Makefile.am as follows

Makefile.am

SUBDIRS=src

src/Makefile.am

mainprgdir=../
mainprg_PROGRAMS=main
main_SOURCES=main.c

I am pretty sure that these files should not be as I have them now 😛

How do I use autotools for the above project structure? (At least what should be there in those Makefile.am(s) and where should I place them.

EDIT:
One more thing! At the end I would like to have the object files created in the bin directory.

Thanks

Answer 1

There are two main approaches. If the functions in SomeLibrarySource are used only by main, then there’s no need to build a separate library and you can simply specify the source files in src/Makefile.am

main_SOURCES = main.c SomeLibrarySource/SomeFuncs.c

However, if you actually want to use the functions in other code in your tree, you do not want to compile SomeFuncs.c multiple times but should use a convenience library.

# Assigning main_SOURCES is redundant
main_SOURCES = main.c
main_LDADD = SomeLibrarySource/libSomeFuncs.a
noinst_LIBRARIES = SomeLibrarySource/libSomeFuncs.a
AM_CPPFLAGS = -I$(srcdir)/SomeLibrarySource

(You’ll need AC_PROG_RANLIB in configure.ac to use convenience libraries.)
If the source file is named SomeFuncs.c, automake will not need Makefile.am to specify SomeLibrarySource_libSomeFuncs_a_SOURCES, but if the name of the source code file does not match the name specified in noinst_LIBRARIES, SomeLibrarySource_libSomeFuncs_a_SOURCES should be set to the list of files used to build the library. Note that you do not need to specify main_SOURCES, since main.c is the default value if left unspecified (but it’s not a bad idea to be explicit.) (In all of this, I am not comfortable use CamlCase names, but the system I’m using uses a case insensitive file system (biggest mistake apple ever made) and the examples I give here are working for me. YMMV)

You could of course do a recursive make, or build the library as a separate project and install it. (I like the final option. Libraries with useful features should exist on their own.)