Adding a compile rule to mkmf.rb


I want to write an extconf.rb file for a Ruby extension. The problem
is that my source file has a suffix that is not any of the expected by
mkmf.rb: ec. The suffixes expected are:

SRC_EXT = [“c”, “cc”, “m”, “cxx”, “cpp”, “C”]

I could add the suffix:

SRC_EXT << “ec”

and even define my own COMPILE_EC rule:

COMPILE_EC = ‘$(ESQL) $(CFLAGS) -c $<’

but how can I extend create_makefile to use this rule, without
modifying mkmf.rb?

Gerardo S.
“Between individuals, as between nations, respect for the rights of
others is peace” - Don Benito Juárez


On Mar 7, 2006, at 10:04 PM, Gerardo S. Gómez Garrido wrote:

and even define my own COMPILE_EC rule:

I don’t think you can :(. I just looked at mkmf, and it looks like
the only way to make an extension for ruby as far as mkmf is
concerned with C or C++. mkmf doesn’t really look for anything
dynamically, those constants seem to be more to save typing than
anything else. :frowning: It’s too bad, it would be neat if mkmf was
extendable in this manner.


Don’t know how you could extend mkmf.rb as you describe, but you could
take the approach that SWIG offers. In the installation of SWIG,
you’ll find Makefile.swig and extconf.rb skeletons (in
/usr/share/swig/1.3.25/ruby/ for my installation).

Makefile.swig has rules for creating the SWIG wrapper (generates a C or
C++ source file wrapper using swig) and also for creating the Makefile
(using ruby,mkmf.rb, and your extconf.rb). Your extconf.rb will
typically check for your library, etc., so that it will be linked into
your extension.

[from Makefile.swig]

File : Makefile.swig

Makefile for a SWIG module. Use this file if you are

producing a Ruby extension for general use or distribution.

1. Prepare extconf.rb.

2. Modify this file as appropriate.

3. Type ‘make -f Makefile.swig’ to generate wrapper code and


4. Type ‘make’ to build your extension.

5. Type ‘make install’ to install your extension.

Perhaps you could create an appropriate Makefile.whatever and an
extconf.rb that will create your extension.

Good luck!