Make an effort at automatically determining the Python include dir

Ignore-this: 9a23e3f1b51804aab62d6cf3222840a0

darcs-hash:20111120043015-0344a-37614883556edbcf451effdc289b310c0a77b50a.gz

burgled-batteries.asd

@@ -17,7 +17,8 @@
 (in-package #:burgled-batteries-system)
 
 (defsystem "burgled-batteries"
-    :depends-on (#:cffi #:alexandria #:parse-declarations-1.0 #:trivial-garbage)
+    :depends-on (#:cffi #:alexandria #:parse-declarations-1.0 #:trivial-garbage
+                        #-burgled-batteries.guess-not-grovel #:cl-fad)
     :name "burgled-batteries"
     :author (:original "Dmitri Hrapof <hrapof@common-lisp.ru>"
              :current "pinterface <pix@kepibu.org>")
@@ -33,17 +34,19 @@ preference for guessing by evaluating the following form before telling ASDF to
 load this system:
   (push :burgled-batteries.guess-not-grovel *features*)
 
-If you /would/ like to use the groveller, you may need to edit the .ASD file to
-configure the directory where Python header files are located.  (My apologies: I
-hope for this to be both more easily configurable, and less necessary, in the
-future.)
+If you /would/ like to use the groveller, B-B will attempt to determine the
+location of Python's C header files, and will prompt you to specify the
+appropriate directory if one cannot be found.  To grovel against a specific
+copy of Python's header files, you may need to edit
+  (defparameter *cpython-include-dir* ...)
+in #p\"grovel-include-dir.lisp\".
 "
     :serial t
     :components
     ((:file "packages")
      #-burgled-batteries.guess-not-grovel (:file "grovel-bitfields")
-     ;; FIXME: auto-detect location of Python include directory (or at least make it configurable)
-     #-burgled-batteries.guess-not-grovel (grovel-file "grovel" :cc-flags ("-I/usr/include/python2.6"))
+     #-burgled-batteries.guess-not-grovel (:file "grovel-include-dir")
+     #-burgled-batteries.guess-not-grovel (grovel-file "grovel")
      #+burgled-batteries.guess-not-grovel (:file "grovel-guess")
      (:file "cffi-output-args")
      (:file "ffi-definers")

grovel-include-dir.lisp

@@ -0,0 +1,28 @@
+(in-package #:cpython)
+
+(defun read-path ()
+  (format *query-io* "Enter directory containing Python's C header files: ")
+  (cl:list (read-line *query-io*)))
+
+(defun query-error (format-string &rest args)
+  (restart-case (apply #'error format-string args)
+    (use-value (v)
+      :report "Specify directory containing CPython's header files"
+      :interactive read-path
+      v)))
+
+(defun query-user-for-include-dir ()
+  (loop :for path := (query-error "Unable to determine Python include directory.")
+               :then (query-error "Path ~s does not appear to exist." path)
+        :when (cl-fad:directory-exists-p path) :return it))
+
+(defparameter *cpython-include-dir*
+  (or (loop :for minor :from 7 :downto 4
+            :when (or (cl-fad:directory-exists-p (format nil "/usr/include/python2.~d" minor))
+                      (cl-fad:directory-exists-p (format nil "/usr/local/include/python2.~d" minor)))
+              :return it)
+      ;; This allows us to avoid querying the user during a recompile, while
+      ;; still allowing for a change in Python version
+      (when (boundp '*cpython-include-dir*)
+        (cl-fad:directory-exists-p *cpython-include-dir*))
+      (query-user-for-include-dir)))

grovel.lisp

@@ -1,5 +1,7 @@
 (in-package #:python.cffi)
 
+(cc-flags #.(format nil "-I~A" *cpython-include-dir*))
+
 (include "Python.h")
 (include "structmember.h") ; needed for member type flags