I'm using ASDF to build an open source implementation of Google's protocol

buffer data serialization library.  The code is here:

  http://github.com/brown/protobuf

I've defined a new component type that allows developers to include protobuf

message definition files in their Lisp ASDF files:

  (defclass protobuf-source-file (cl-source-file)

    ((relative-proto-pathname ... )

     (search-path ... )

    (:documentation "A protocol buffer definition file."))

When used like this in a system definition:

  :components ((:protobuf-source-file "foo"))

executing the ASDF:LOAD-OP operation causes the file called foo.proto to be

translated into foo.lisp by a C++ program, and then compiled into foo.fasl

and loaded.

Note that foo.lisp is created in the same directory as the system

definition, but I would prefer it to be created in the same directory as

foo.fasl, which for me is in a subdirectory of ~/.cache/common-lisp.

What's the easiest way to accomplish this?

I initially tried overriding INPUT-FILES when applied to CL-SOURCE-FILE

instances, but ASDF::PERFORM is defined like this:

  (defmethod perform ((operation compile-op) (c cl-source-file))

    (let ((source-file (component-pathname c)) ... ) ... )

Since it calls COMPONENT-PATHNAME to find Lisp source, it will always look

in the system definition directory.

bob