;;; -*- mode: common-lisp; package: asdf; -*-
;;; This is asdf: Another System Definition Facility.
;;;
;;; Feedback, bug reports, and patches are all welcome:
;;; please mail to <asdf-devel@common-lisp.net>.
;;; Note first that the canonical source for asdf is presently
;;; <URL:http://common-lisp.net/project/asdf/>.
;;;
;;; If you obtained this copy from anywhere else, and you experience
;;; trouble using it, or find bugs, you may want to check at the
;;; location above for a more recent version (and for documentation
;;; and test files, if your copy came without them) before reporting
;;; bugs.  There are usually two "supported" revisions - the git HEAD
;;; is the latest development version, whereas the revision tagged
;;; RELEASE may be slightly older but is considered `stable'

;;; -- LICENSE START
;;; (This is the MIT / X Consortium license as taken from
;;;  http://www.opensource.org/licenses/mit-license.html on or about
;;;  Monday; July 13, 2009)
;;;
;;; Copyright (c) 2001-2010 Daniel Barlow and contributors
;;;
;;; Permission is hereby granted, free of charge, to any person obtaining
;;; a copy of this software and associated documentation files (the
;;; "Software"), to deal in the Software without restriction, including
;;; without limitation the rights to use, copy, modify, merge, publish,
;;; distribute, sublicense, and/or sell copies of the Software, and to
;;; permit persons to whom the Software is furnished to do so, subject to
;;; the following conditions:
;;;
;;; The above copyright notice and this permission notice shall be
;;; included in all copies or substantial portions of the Software.
;;;
;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
;;; NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
;;; LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
;;; OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
;;; WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
;;;
;;; -- LICENSE END

;;; The problem with writing a defsystem replacement is bootstrapping:
;;; we can't use defsystem to compile it.  Hence, all in one file.

#+xcvb (module ())

(cl:in-package :cl-user)

(declaim (optimize (speed 2) (debug 2) (safety 3)))

#+ecl (require 'cmp)

;;;; Create packages in a way that is compatible with hot-upgrade.
;;;; See https://bugs.launchpad.net/asdf/+bug/485687
;;;; See more at the end of the file.

(eval-when (:load-toplevel :compile-toplevel :execute)
  (labels ((rename-away (package)
             (loop :with name = (package-name package)
               :for i :from 1 :for n = (format nil "~A.~D" name i)
               :unless (find-package n) :do (rename-package package n)))
           (ensure-exists (name nicknames use)
             (let* ((previous
                     (remove-duplicates
                      (remove-if
                       #'null
                       (mapcar #'find-package (cons name nicknames)))
                      :from-end t)))
               (cond
                 (previous
                  (map () #'rename-away (cdr previous))
                  (let ((p (car previous)))
                    (rename-package p name nicknames)
                    (ensure-use p use)
                    p))
                 (t
                  (make-package name :nicknames nicknames :use use)))))
           (remove-symbol (symbol package)
             (let ((sym (find-symbol (string symbol) package)))
               (when sym
                 (unexport sym package)
                 (unintern sym package))))
           (ensure-unintern (package symbols)
             (dolist (sym symbols) (remove-symbol sym package)))
           (ensure-shadow (package symbols)
             (shadow symbols package))
           (ensure-use (package use)
             (dolist (used (reverse use))
               (do-external-symbols (sym used)
                 (unless (eq sym (find-symbol (string sym) package))
                   (remove-symbol sym package)))
               (use-package used package)))
           (ensure-export (package export)
             (let ((syms (loop :for x :in export :collect
                           (intern (string x) package))))
               (do-external-symbols (sym package)
                 (unless (member sym syms)
                   (remove-symbol sym package)))
               (dolist (sym syms)
                 (export sym package))))
           (ensure-package (name &key nicknames use unintern shadow export)
             (let ((p (ensure-exists name nicknames use)))
               (ensure-unintern p unintern)
               (ensure-shadow p shadow)
               (ensure-export p export)
               p)))
    (ensure-package
     ':asdf-utilities
     :nicknames '(#:asdf-extensions)
     :use '(#:common-lisp)
     :unintern '(#:split #:make-collector)
     :export
     '(#:absolute-pathname-p
       #:aif
       #:appendf
       #:asdf-message
       #:coerce-name
       #:directory-pathname-p
       #:ends-with
       #:ensure-directory-pathname
       #:getenv
       #:get-uid
       #:length=n-p
       #:merge-pathnames*
       #:pathname-directory-pathname
       #:pathname-sans-name+type ;; deprecated. Use pathname-directory-pathname
       #:read-file-forms
       #:remove-keys
       #:remove-keyword
       #:resolve-symlinks
       #:split-string
       #:component-name-to-pathname-components
       #:split-name-type
       #:system-registered-p
       #:truenamize
       #:while-collecting))
    (ensure-package
     ':asdf
     :use '(:common-lisp :asdf-utilities)
     :unintern '(#:*asdf-revision*)
     :export
     '(#:defsystem #:oos #:operate #:find-system #:run-shell-command
       #:system-definition-pathname #:find-component ; miscellaneous
       #:compile-system #:load-system #:test-system
       #:compile-op #:load-op #:load-source-op
       #:test-op
       #:operation                 ; operations
       #:feature                 ; sort-of operation
       #:version                 ; metaphorically sort-of an operation

       #:input-files #:output-files #:perform ; operation methods
       #:operation-done-p #:explain

       #:component #:source-file
       #:c-source-file #:cl-source-file #:java-source-file
       #:static-file
       #:doc-file
       #:html-file
       #:text-file
       #:source-file-type
       #:module                     ; components
       #:system
       #:unix-dso

       #:module-components          ; component accessors
       #:component-pathname
       #:component-relative-pathname
       #:component-name
       #:component-version
       #:component-parent
       #:component-property
       #:component-system

       #:component-depends-on

       #:system-description
       #:system-long-description
       #:system-author
       #:system-maintainer
       #:system-license
       #:system-licence
       #:system-source-file
       #:system-relative-pathname
       #:map-systems

       #:operation-on-warnings
       #:operation-on-failure

                                        ;#:*component-parent-pathname*
       #:*system-definition-search-functions*
       #:*central-registry*         ; variables
       #:*compile-file-warnings-behaviour*
       #:*compile-file-failure-behaviour*
       #:*resolve-symlinks*

       #:asdf-version

       #:operation-error #:compile-failed #:compile-warned #:compile-error
       #:error-name
       #:error-pathname
       #:missing-definition
       #:error-component #:error-operation
       #:system-definition-error
       #:missing-component
       #:missing-component-of-version
       #:missing-dependency
       #:missing-dependency-of-version
       #:circular-dependency        ; errors
       #:duplicate-names

       #:try-recompiling
       #:retry
       #:accept                     ; restarts
       #:coerce-entry-to-directory
       #:remove-entry-from-registry

       #:standard-asdf-method-combination
       #:around                     ; protocol assistants

       #:initialize-output-translations
       #:clear-output-translations
       #:ensure-output-translations
       #:apply-output-translations
       #:compile-file-pathname*

       #:*default-source-registries*
       #:initialize-source-registry
       #:compute-source-registry
       #:clear-source-registry
       #:ensure-source-registry
       #:process-source-registry))))

#+nil
(error "The author of this file habitually uses #+nil to comment out ~
        forms. But don't worry, it was unlikely to work in the New ~
        Implementation of Lisp anyway")

(in-package #:asdf)

;;;; -------------------------------------------------------------------------
;;;; User-visible parameters
;;;;
(defparameter *asdf-version*
  ;; This parameter isn't actually user-visible
  ;; -- please use the exported function ASDF:ASDF-VERSION below.
  ;; the 1+ hair is to ensure that we don't do an inadvertent find and replace
  (subseq "VERSION:1.635" (1+ (length "VERSION"))))

(defun asdf-version ()
  "Exported interface to the version of ASDF currently installed. A string.

Not officially supported:
you can compare this string with ASDF::VERSION-SATISFIES."
  *asdf-version*)

(defvar *resolve-symlinks* t
  "Determine whether or not ASDF resolves symlinks when defining systems.

Defaults to `t`.")

(defvar *compile-file-warnings-behaviour* :warn)

(defvar *compile-file-failure-behaviour* #+sbcl :error #-sbcl :warn)

(defvar *verbose-out* nil)

(defparameter +asdf-methods+
  '(perform explain output-files operation-done-p))

#+allegro
(eval-when (:compile-toplevel :execute)
  (defparameter *acl-warn-save*
                (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
                  excl:*warn-on-nested-reader-conditionals*))
  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
    (setf excl:*warn-on-nested-reader-conditionals* nil)))

;;;; -------------------------------------------------------------------------
;;;; Cleanups before hot-upgrade.
;;;; Things to do in case we're upgrading from a previous version of ASDF.
;;;; See https://bugs.launchpad.net/asdf/+bug/485687
;;;; * fmakunbound functions that once (in previous version of ASDF)
;;;;   were simple DEFUNs but now are generic functions.
;;;; * define methods on UPDATE-INSTANCE-FOR-REDEFINED-CLASS
;;;;   for each of the classes we define that has changed incompatibly.
(eval-when (:compile-toplevel :load-toplevel :execute)
  (when (and (fboundp 'system-source-file)
             (not (typep (fdefinition 'system-source-file) 'generic-function)))
    (fmakunbound 'system-source-file))
  (map () 'fmakunbound '(process-source-registry inherit-source-registry
                         process-source-registry-directive))
  #+ecl
  (when (find-class 'compile-op nil)
    (defmethod update-instance-for-redefined-class :after
        ((c compile-op) added deleted plist &key)
      (format *trace-output* "~&UI4RC:a ~S~%" (list c added deleted plist))
      (let ((system-p (getf plist 'system-p)))
        (when system-p (setf (getf (slot-value c 'flags) :system-p) system-p))))))

;;;; -------------------------------------------------------------------------
;;;; CLOS magic for asdf:around methods

(define-method-combination standard-asdf-method-combination ()
  ((around-asdf (around))
   (around (:around))
   (before (:before))
   (primary () :required t)
   (after (:after)))
  (flet ((call-methods (methods)
           (mapcar #'(lambda (method)
                       `(call-method ,method))
                   methods)))
    (let* ((form (if (or before after (rest primary))
                     `(multiple-value-prog1
                          (progn ,@(call-methods before)
                                 (call-method ,(first primary)
                                              ,(rest primary)))
                        ,@(call-methods (reverse after)))
                     `(call-method ,(first primary))))
           (standard-form (if around
                              `(call-method ,(first around)
                                            (,@(rest around)
                                               (make-method ,form)))
                              form)))
      (if around-asdf
          `(call-method ,(first around-asdf)
                        (,@(rest around-asdf) (make-method ,standard-form)))
          standard-form))))

(setf (documentation 'standard-asdf-method-combination
                     'method-combination)
      "This method combination is based on the standard method combination,
but defines a new method-qualifier, `asdf:around`.  `asdf:around`
methods will be run *around* any `:around` methods, so that the core
protocol may employ around methods and those around methods will not
be overridden by around methods added by a system developer.")

;;;; -------------------------------------------------------------------------
;;;; ASDF Interface, in terms of generic functions.

(defgeneric perform (operation component)
  (:method-combination standard-asdf-method-combination))
(defgeneric operation-done-p (operation component)
  (:method-combination standard-asdf-method-combination))
(defgeneric explain (operation component)
  (:method-combination standard-asdf-method-combination))
(defgeneric output-files (operation component)
  (:method-combination standard-asdf-method-combination))
(defgeneric input-files (operation component)
  (:method-combination standard-asdf-method-combination))

(defgeneric system-source-file (system)
  (:documentation "Return the source file in which system is defined."))

(defgeneric component-system (component)
  (:documentation "Find the top-level system containing COMPONENT"))

(defgeneric component-pathname (component)
  (:documentation "Extracts the pathname applicable for a particular component."))

(defgeneric component-relative-pathname (component)
  (:documentation "Returns a pathname for the component argument intended to be
interpreted relative to the pathname of that component's parent.
Despite the function's name, the return value may be an absolute
pathname, because an absolute pathname may be interpreted relative to
another pathname in a degenerate way."))

(defgeneric component-property (component property))

(defgeneric (setf component-property) (new-value component property))

(defgeneric version-satisfies (component version))

(defgeneric find-component (module name &optional version)
  (:documentation "Finds the component with name NAME present in the
MODULE module; if MODULE is nil, then the component is assumed to be a
system."))

(defgeneric source-file-type (component system))

(defgeneric operation-ancestor (operation)
  (:documentation
   "Recursively chase the operation's parent pointer until we get to
the head of the tree"))

(defgeneric component-visited-p (operation component)
  (:documentation "Returns the value stored by a call to
VISIT-COMPONENT, if that has been called, otherwise NIL.
This value stored will be a cons cell, the first element
of which is a computed key, so not interesting.  The
CDR wil be the DATA value stored by VISIT-COMPONENT; recover
it as \(cdr \(component-visited-p op c\)\).
  In the current form of ASDF, the DATA value retrieved is
effectively a boolean, indicating whether some operations are
to be performed in order to do OPERATION X COMPONENT.  If the
data value is NIL, the combination had been explored, but no
operations needed to be performed."))

(defgeneric visit-component (operation component data)
  (:documentation "Record DATA as being associated with OPERATION
and COMPONENT.  This is a side-effecting function:  the association
will be recorded on the ROOT OPERATION \(OPERATION-ANCESTOR of the
OPERATION\).
  No evidence that DATA is ever interesting, beyond just being
non-NIL.  Using the data field is probably very risky; if there is
already a record for OPERATION X COMPONENT, DATA will be quietly
discarded instead of recorded."))

(defgeneric (setf visiting-component) (new-value operation component))

(defgeneric component-visiting-p (operation component))

(defgeneric component-depends-on (operation component)
  (:documentation
   "Returns a list of dependencies needed by the component to perform
    the operation.  A dependency has one of the following forms:

      (<operation> <component>*), where <operation> is a class
        designator and each <component> is a component
        designator, which means that the component depends on
        <operation> having been performed on each <component>; or

      (FEATURE <feature>), which means that the component depends
        on <feature>'s presence in *FEATURES*.

    Methods specialized on subclasses of existing component types
    should usually append the results of CALL-NEXT-METHOD to the
    list."))

(defgeneric component-self-dependencies (operation component))

(defgeneric traverse (operation component)
  (:documentation
"Generate and return a plan for performing `operation` on `component`.

The plan returned is a list of dotted-pairs. Each pair is the `cons`
of ASDF operation object and a `component` object. The pairs will be
processed in order by `operate`."))

(defgeneric output-files-using-mappings (source possible-paths path-mappings)
  (:documentation
"Use the variable \\*source-to-target-mappings\\* to find
an output path for the source. The algorithm transforms each
entry in possible-paths as follows: If there is a mapping
whose source starts with the path of possible-path, then
replace possible-path with a pathname that starts with the
target of the mapping and continues with the rest of
possible-path. If no such mapping is found, then use the
default mapping.

If \\*centralize-lisp-binaries\\* is false, then the default
mapping is to place the output in a subdirectory of the
source. The subdirectory is named using the Lisp
implementation \(see
implementation-specific-directory-name\). If
\\*centralize-lisp-binaries\\* is true, then the default
mapping is to place the output in subdirectories of
\\*default-toplevel-directory\\* where the subdirectory
structure will mirror that of the source."))


;;;; -------------------------------------------------------------------------
;;;; General Purpose Utilities

(defmacro while-collecting ((&rest collectors) &body body)
  (let ((vars (mapcar #'(lambda (x) (gensym (symbol-name x))) collectors))
        (initial-values (mapcar (constantly nil) collectors)))
    `(let ,(mapcar #'list vars initial-values)
       (flet ,(mapcar #'(lambda (c v) `(,c (x) (push x ,v))) collectors vars)
         ,@body
         (values ,@(mapcar #'(lambda (v) `(nreverse ,v)) vars))))))

(defmacro aif (test then &optional else)
  `(let ((it ,test)) (if it ,then ,else)))

(defun pathname-sans-name+type (pathname)
  "Returns a new pathname with same HOST, DEVICE, DIRECTORY as PATHNAME,
and NIL NAME and TYPE components.
Issue: doesn't override the VERSION component.

Deprecated. Use PATHNAME-DIRECTORY-PATHNAME instead."
  (make-pathname :name nil :type nil :defaults pathname))

(defun pathname-directory-pathname (pathname)
  "Returns a new pathname with same HOST, DEVICE, DIRECTORY as PATHNAME,
and NIL NAME, TYPE and VERSION components"
  (make-pathname :name nil :type nil :version nil :defaults pathname))

(defun merge-pathnames* (specified &optional (defaults *default-pathname-defaults*))
  "MERGE-PATHNAMES* is like MERGE-PATHNAMES except that if the SPECIFIED pathname
does not have an absolute directory, then the HOST and DEVICE come from the DEFAULTS."
  (let* ((specified (pathname specified))
         (defaults (pathname defaults))
         (directory (pathname-directory specified))
         (directory (if (stringp directory) `(:absolute ,directory) directory))
         (name (or (pathname-name specified) (pathname-name defaults)))
         (type (or (pathname-type specified) (pathname-type defaults)))
         (version (or (pathname-version specified) (pathname-version defaults))))
    (multiple-value-bind (host device directory)
        (ecase (first directory)
          ((nil)
           (values (pathname-host defaults)
                   (pathname-device defaults)
                   (pathname-directory defaults)))
          ((:absolute)
           (values (pathname-host specified)
                   (pathname-device specified)
                   directory))
          ((:relative)
           (values (pathname-host defaults)
                   (pathname-device defaults)
                   (append (pathname-directory defaults) (cdr directory)))))
      (make-pathname :host host :device device :directory directory
                     :name name :type type :version version))))

(define-modify-macro appendf (&rest args)
  append "Append onto list")

(defun asdf-message (format-string &rest format-args)
  (declare (dynamic-extent format-args))
  (apply #'format *verbose-out* format-string format-args))

(defun split-string (string &key max (separator '(#\Space #\Tab)))
  ;; Beware: this API function has changed in ASDF 1.628!
  ;; optional arguments became keyword arguments, and max now works from the end.
  "Split STRING in components separater by any of the characters in the sequence SEPARATOR,
return a list.
If MAX is specified, then no more than max(1,MAX) components will be returned,
starting the separation from the end, e.g. when called with arguments
 \"a.b.c.d.e\" :max 3 :separator \".\" it will return (\"a.b.c\" \"d\" \"e\")."
  (block nil
    (let ((list nil) (words 0) (end (length string)))
      (flet ((separatorp (char) (find char separator))
             (done () (return (cons (subseq string 0 end) list))))
        (loop
          :for start = (if (and max (>= words (1- max)))
                           (done)
                           (position-if #'separatorp string :end end :from-end t)) :do
          (when (null start)
            (done))
          (push (subseq string (1+ start) end) list)
          (incf words)
          (setf end start))))))

(defun split-name-type (filename)
  (destructuring-bind (name &optional type)
      (split-string filename :max 2 :separator ".")
    (if (equal name "")
        (values filename nil)
        (values name type))))

(defun component-name-to-pathname-components (s &optional force-directory)
  "Splits the path string S, returning three values:
A flag that is either :absolute or :relative, indicating
   how the rest of the values are to be interpreted.
A directory path --- a list of strings, suitable for
   use with MAKE-PATHNAME when prepended with the flag
   value.
A filename with type extension, possibly NIL in the
   case of a directory pathname.
FORCE-DIRECTORY forces S to be interpreted as a directory
pathname \(third return value will be NIL, final component
of S will be treated as part of the directory path.

The intention of this function is to support structured component names,
e.g., \(:file \"foo/bar\"\), which will be unpacked to relative
pathnames."
  (check-type s string)
  (let* ((components (split-string s :separator "/"))
         (last-comp (car (last components))))
    (multiple-value-bind (relative components)
        (if (equal (first components) "")
            (if (and (plusp (length s)) (eql (char s 0) #\/))
                (values :absolute (cdr components))
                (values :relative nil))
          (values :relative components))
      (cond
        ((equal last-comp "")
         (values relative (butlast components) nil))
        (force-directory
         (values relative components nil))
        (t
         (values relative (butlast components) last-comp))))))

(defun remove-keys (key-names args)
  (loop :for (name val) :on args :by #'cddr
    :unless (member (symbol-name name) key-names
                    :key #'symbol-name :test 'equal)
    :append (list name val)))

(defun remove-keyword (key args)
  (loop :for (k v) :on args :by #'cddr
    :unless (eq k key)
    :append (list k v)))

(defun resolve-symlinks (path)
  #-allegro (truename path)
  #+allegro (excl:pathname-resolve-symbolic-links path))

(defun getenv (x)
  #+sbcl
  (sb-ext:posix-getenv x)
  #+clozure
  (ccl::getenv x)
  #+clisp
  (ext:getenv x)
  #+cmu
  (cdr (assoc (intern x :keyword) ext:*environment-list*))
  #+lispworks
  (lispworks:environment-variable x)
  #+allegro
  (sys:getenv x)
  #+gcl
  (system:getenv x)
  #+ecl
  (si:getenv x))

(defun directory-pathname-p (pathname)
  "Does `pathname` represent a directory?

A directory-pathname is a pathname _without_ a filename. The three
ways that the filename components can be missing are for it to be `nil`,
`:unspecific` or the empty string.

Note that this does _not_ check to see that `pathname` points to an
actually-existing directory."
  (flet ((check-one (x)
           (not (null (member x '(nil :unspecific "")
                              :test 'equal)))))
    (and (check-one (pathname-name pathname))
         (check-one (pathname-type pathname)))))

(defun ensure-directory-pathname (pathspec)
  "Converts the non-wild pathname designator PATHSPEC to directory form."
  (cond
   ((stringp pathspec)
    (pathname
     (let ((lastchar (aref pathspec (1- (length pathspec)))))
       (cond ((or (eql lastchar #\;) (eql lastchar #\/)) pathspec)
             ((find #\; pathspec) ;; assume a ; means a logical pathname directory separator
              (concatenate 'string pathspec ";"))
             (t
              ;; guess it's a string that's not a logical
              ;; pathname string
              (concatenate 'string pathspec "/"))))))
   ((not (pathnamep pathspec))
    (error "Invalid pathname designator ~S" pathspec))
   ((wild-pathname-p pathspec)
    (error "Can't reliably convert wild pathnames."))
   ((directory-pathname-p pathspec)
    pathspec)
   (t
    (make-pathname :directory (append (or (pathname-directory pathspec)
                                          (list :relative))
                                      (list (file-namestring pathspec)))
                   :name nil :type nil :version nil
                   :defaults pathspec))))

(defun absolute-pathname-p (pathspec)
  (eq :absolute (car (pathname-directory (pathname pathspec)))))

(defun length=n-p (x n) ;is it that (= (length x) n) ?
  (check-type n (integer 0 *))
  (loop
    :for l = x :then (cdr l)
    :for i :downfrom n :do
    (cond
      ((zerop i) (return (null l)))
      ((not (consp l)) (return nil)))))

(defun ends-with (s suffix)
  (check-type s string)
  (check-type suffix string)
  (let ((start (- (length s) (length suffix))))
    (and (<= 0 start)
         (string-equal s suffix :start1 start))))

(defun read-file-forms (file)
  (with-open-file (in file)
    (loop :with eof = (list nil)
     :for form = (read in nil eof)
     :until (eq form eof)
     :collect form)))

#-windows
(progn
#+clisp (defun get-uid () (posix:uid))
#+sbcl (defun get-uid () (sb-unix:unix-getuid))
#+cmu (defun get-uid () (unix:unix-getuid))
#+ecl (defun get-uid () (ffi:c-inline () () :int "getuid()" :one-liner t))
#+allegro (defun get-uid () (excl.osi:getuid))
#-(or cmu sbcl clisp allegro ecl)
(defun get-uid ()
  (let ((uid-string
         (with-output-to-string (asdf::*VERBOSE-OUT*)
           (asdf:run-shell-command "id -ur"))))
    (with-input-from-string (stream uid-string)
      (read-line stream)
      (handler-case (parse-integer (read-line stream))
        (error () (error "Unable to find out user ID")))))))

(defun truenamize (p)
  "Resolve as much of a pathname as possible"
  (block nil
    (when (typep p 'logical-pathname) (return p))
    (ignore-errors (return (truename p)))
    (let ((host (pathname-host p))
          (device (pathname-device p))
          (directory (pathname-directory p)))
      (when (or (atom directory) (not (eq :absolute (car directory))))
        (return p))
      (let ((sofar (ignore-errors
                     (truename (make-pathname :host host :device device
                                              :directory '(:absolute))))))
        (unless sofar (return p))
        (loop :for component :in (cdr directory)
          :for rest :on (cdr directory)
          :for more = (ignore-errors
                        (truename
                         (merge-pathnames*
                          (make-pathname :directory `(:relative ,component))
                          sofar))) :do
          (if more
              (setf sofar more)
              (return
                (merge-pathnames*
                 (make-pathname :host nil :device nil
                                :directory `(:relative ,@rest)
                                :defaults p)
                 sofar)))
          :finally
          (return
            (merge-pathnames*
             (make-pathname :host nil :device nil
                            :directory nil
                            :defaults p)
             sofar)))))))

;;;; -------------------------------------------------------------------------
;;;; Classes, Conditions

(define-condition system-definition-error (error) ()
  ;; [this use of :report should be redundant, but unfortunately it's not.
  ;; cmucl's lisp::output-instance prefers the kernel:slot-class-print-function
  ;; over print-object; this is always conditions::%print-condition for
  ;; condition objects, which in turn does inheritance of :report options at
  ;; run-time.  fortunately, inheritance means we only need this kludge here in
  ;; order to fix all conditions that build on it.  -- rgr, 28-Jul-02.]
  #+cmu (:report print-object))

(define-condition formatted-system-definition-error (system-definition-error)
  ((format-control :initarg :format-control :reader format-control)
   (format-arguments :initarg :format-arguments :reader format-arguments))
  (:report (lambda (c s)
             (apply #'format s (format-control c) (format-arguments c)))))

(define-condition missing-definition (system-definition-error)
  ((name :initarg :name :reader error-name)
   (pathname :initarg :pathname :reader error-pathname))
  (:report (lambda (c s)
             (format s "~@<Definition search function returned a wrong pathname ~A ~
                           in search of a definition for system ~A.~@:>"
                     (error-pathname c) (error-name c)))))

(define-condition circular-dependency (system-definition-error)
  ((components :initarg :components :reader circular-dependency-components)))

(define-condition duplicate-names (system-definition-error)
  ((name :initarg :name :reader duplicate-names-name)))

(define-condition missing-component (system-definition-error)
  ((requires :initform "(unnamed)" :reader missing-requires :initarg :requires)
   (parent :initform nil :reader missing-parent :initarg :parent)))

(define-condition missing-component-of-version (missing-component)
  ((version :initform nil :reader missing-version :initarg :version)))

(define-condition missing-dependency (missing-component)
  ((required-by :initarg :required-by :reader missing-required-by)))

(define-condition missing-dependency-of-version (missing-dependency
                                                 missing-component-of-version)
  ())

(define-condition operation-error (error)
  ((component :reader error-component :initarg :component)
   (operation :reader error-operation :initarg :operation))
  (:report (lambda (c s)
             (format s "~@<erred while invoking ~A on ~A~@:>"
                     (error-operation c) (error-component c)))))
(define-condition compile-error (operation-error) ())
(define-condition compile-failed (compile-error) ())
(define-condition compile-warned (compile-error) ())

(defclass component ()
  ((name :accessor component-name :initarg :name :documentation
         "Component name: designator for a string composed of portable pathname characters")
   (version :accessor component-version :initarg :version)
   (in-order-to :initform nil :initarg :in-order-to
                :accessor component-in-order-to)
   ;; XXX crap name
   (do-first :initform nil :initarg :do-first
             :accessor component-do-first)
   ;; methods defined using the "inline" style inside a defsystem form:
   ;; need to store them somewhere so we can delete them when the system
   ;; is re-evaluated
   (inline-methods :accessor component-inline-methods :initform nil)
   (parent :initarg :parent :initform nil :reader component-parent)
   ;; no direct accessor for pathname, we do this as a method to allow
   ;; it to default in funky ways if not supplied
   (relative-pathname :initarg :pathname)
   (operation-times :initform (make-hash-table)
                    :accessor component-operation-times)
   ;; XXX we should provide some atomic interface for updating the
   ;; component properties
   (properties :accessor component-properties :initarg :properties
               :initform nil)))

;;;; methods: conditions

(defmethod print-object ((c missing-dependency) s)
  (format s "~@<~A, required by ~A~@:>"
          (call-next-method c nil) (missing-required-by c)))

(defun sysdef-error (format &rest arguments)
  (error 'formatted-system-definition-error :format-control
         format :format-arguments arguments))

;;;; methods: components

(defmethod print-object ((c missing-component) s)
   (format s "~@<component ~S not found~
             ~@[ in ~A~]~@:>"
          (missing-requires c)
          (when (missing-parent c)
            (component-name (missing-parent c)))))

(defmethod print-object ((c missing-component-of-version) s)
  (format s "~@<component ~S does not match version ~A~
              ~@[ in ~A~]~@:>"
           (missing-requires c)
           (missing-version c)
           (when (missing-parent c)
             (component-name (missing-parent c)))))

(defmethod component-system ((component component))
  (aif (component-parent component)
       (component-system it)
       component))

(defmethod print-object ((c component) stream)
  (print-unreadable-object (c stream :type t :identity t)
    (ignore-errors
      (prin1 (component-name c) stream))))

(defclass module (component)
  ((components :initform nil :accessor module-components :initarg :components)
   ;; what to do if we can't satisfy a dependency of one of this module's
   ;; components.  This allows a limited form of conditional processing
   (if-component-dep-fails :initform :fail
                           :accessor module-if-component-dep-fails
                           :initarg :if-component-dep-fails)
   (default-component-class :accessor module-default-component-class
     :initform 'cl-source-file :initarg :default-component-class)))

(defun component-parent-pathname (component)
  (aif (component-parent component)
       (component-pathname it)
       (truename *default-pathname-defaults*)))

(defmethod component-pathname ((component component))
  (merge-pathnames* (component-relative-pathname component)
                    (component-parent-pathname component)))

(defmethod component-property ((c component) property)
  (cdr (assoc property (slot-value c 'properties) :test #'equal)))

(defmethod (setf component-property) (new-value (c component) property)
  (let ((a (assoc property (slot-value c 'properties) :test #'equal)))
    (if a
        (setf (cdr a) new-value)
        (setf (slot-value c 'properties)
              (acons property new-value (slot-value c 'properties))))))

(defclass system (module)
  ((description :accessor system-description :initarg :description)
   (long-description
    :accessor system-long-description :initarg :long-description)
   (author :accessor system-author :initarg :author)
   (maintainer :accessor system-maintainer :initarg :maintainer)
   (licence :accessor system-licence :initarg :licence
            :accessor system-license :initarg :license)
   (source-file :reader system-source-file :initarg :source-file
                :writer %set-system-source-file)))

;;;; -------------------------------------------------------------------------
;;;; version-satisfies

(defmethod version-satisfies ((c component) version)
  (unless (and version (slot-boundp c 'version))
    (return-from version-satisfies t))
  (version-satisfies (component-version c) version))

(defmethod version-satisfies ((cver string) version)
  (let ((x (mapcar #'parse-integer
                   (split-string cver :separator ".")))
        (y (mapcar #'parse-integer
                   (split-string version :separator "."))))
    (labels ((bigger (x y)
               (cond ((not y) t)
                     ((not x) nil)
                     ((> (car x) (car y)) t)
                     ((= (car x) (car y))
                      (bigger (cdr x) (cdr y))))))
      (and (= (car x) (car y))
           (or (not (cdr y)) (bigger (cdr x) (cdr y)))))))

;;;; -------------------------------------------------------------------------
;;;; Finding systems

(defun make-defined-systems-table ()
  (make-hash-table :test 'equal))

(defvar *defined-systems* (make-defined-systems-table)
  "This is a hash table whose keys are strings, being the
names of the systems, and whose values are pairs, the first
element of which is a universal-time indicating when the
system definition was last updated, and the second element
of which is a system object.")

(defun coerce-name (name)
  (typecase name
    (component (component-name name))
    (symbol (string-downcase (symbol-name name)))
    (string name)
    (t (sysdef-error "~@<invalid component designator ~A~@:>" name))))

(defun system-registered-p (name)
  (gethash (coerce-name name) *defined-systems*))

(defun map-systems (fn)
  "Apply `fn` to each defined system.

`fn` should be a function of one argument. It will be
called with an object of type asdf:system."
  (maphash (lambda (_ datum)
             (declare (ignore _))
             (destructuring-bind (_ . def) datum
               (declare (ignore _))
               (funcall fn def)))
           *defined-systems*))

;;; for the sake of keeping things reasonably neat, we adopt a
;;; convention that functions in this list are prefixed SYSDEF-

(defparameter *system-definition-search-functions*
  '(sysdef-central-registry-search sysdef-source-registry-search))

(defun system-definition-pathname (system)
  (let ((system-name (coerce-name system)))
    (or
     (some (lambda (x) (funcall x system-name))
           *system-definition-search-functions*)
     (let ((system-pair (system-registered-p system-name)))
       (and system-pair
            (system-source-file (cdr system-pair)))))))

(defvar *central-registry* nil
"A list of 'system directory designators' ASDF uses to find systems.

A 'system directory designator' is a pathname or an expression
which evaluates to a pathname. For example:

    (setf asdf:*central-registry*
          (list '*default-pathname-defaults*
                #p\"/home/me/cl/systems/\"
                #p\"/usr/share/common-lisp/systems/\"))

This is for backward compatibilily.
Going forward, we recommend new users should be using the source-registry.
")

(defun sysdef-central-registry-search (system)
  (let ((name (coerce-name system))
        (to-remove nil)
        (to-replace nil))
    (block nil
      (unwind-protect
           (dolist (dir *central-registry*)
             (let ((defaults (eval dir)))
               (when defaults
                 (cond ((directory-pathname-p defaults)
                        (let ((file (and defaults
                                         (make-pathname
                                          :defaults defaults :version :newest
                                          :name name :type "asd" :case :local)))
                               #+(and (or win32 windows) (not :clisp))
                               (shortcut (make-pathname
                                          :defaults defaults :version :newest
                                          :name name :type "asd.lnk" :case :local)))
                          (if (and file (probe-file file))
                              (return file))
                          #+(and (or win32 windows) (not :clisp))
                          (when (probe-file shortcut)
                            (let ((target (parse-windows-shortcut shortcut)))
                              (when target
                                (return (pathname target)))))))
                       (t
                        (restart-case
                            (let* ((*print-circle* nil)
                                   (message
                                    (format nil
                                            "~@<While searching for system `~a`: `~a` evaluated ~
to `~a` which is not a directory.~@:>"
                                            system dir defaults)))
                              (error message))
                          (remove-entry-from-registry ()
                            :report "Remove entry from *central-registry* and continue"
                            (push dir to-remove))
                          (coerce-entry-to-directory ()
                            :report (lambda (s)
                                      (format s "Coerce entry to ~a, replace ~a and continue."
                                              (ensure-directory-pathname defaults) dir))
                            (push (cons dir (ensure-directory-pathname defaults)) to-replace))))))))
        ;; cleanup
        (dolist (dir to-remove)
          (setf *central-registry* (remove dir *central-registry*)))
        (dolist (pair to-replace)
          (let* ((current (car pair))
                 (new (cdr pair))
                 (position (position current *central-registry*)))
            (setf *central-registry*
                  (append (subseq *central-registry* 0 position)
                          (list new)
                          (subseq *central-registry* (1+ position))))))))))

(defun make-temporary-package ()
  (flet ((try (counter)
           (ignore-errors
             (make-package (format nil "~a~D" 'asdf counter)
                           :use '(:cl :asdf)))))
    (do* ((counter 0 (+ counter 1))
          (package (try counter) (try counter)))
         (package package))))

(defun safe-file-write-date (pathname)
           ;; if FILE-WRITE-DATE returns NIL, it's possible that the
           ;; user or some other agent has deleted an input file.  If
           ;; that's the case, well, that's not good, but as long as
           ;; the operation is otherwise considered to be done we
           ;; could continue and survive.
  (or (file-write-date pathname)
      (progn
        (warn "Missing FILE-WRITE-DATE for ~S: treating it as zero."
              pathname)
        0)))

(defun find-system (name &optional (error-p t))
  (let* ((name (coerce-name name))
         (in-memory (system-registered-p name))
         (on-disk (system-definition-pathname name)))
    (when (and on-disk
               (or (not in-memory)
                   (< (car in-memory) (safe-file-write-date on-disk))))
      (let ((package (make-temporary-package)))
        (unwind-protect
             (with-open-file (asd on-disk :if-does-not-exist nil)
               (if asd
                   (let ((*package* package))
                     (asdf-message
                      "~&~@<; ~@;loading system definition from ~A into ~A~@:>~%"
                      ;; FIXME: This wants to be (ENOUGH-NAMESTRING
                      ;; ON-DISK), but CMUCL barfs on that.
                      on-disk
                      *package*)
                     (load on-disk))
                   (error 'missing-definition :name name :pathname on-disk)))
          (delete-package package))))
    (let ((in-memory (system-registered-p name)))
      (if in-memory
          (progn (if on-disk (setf (car in-memory)
                                   (safe-file-write-date on-disk)))
                 (cdr in-memory))
          (if error-p (error 'missing-component :requires name))))))

(defun register-system (name system)
  (asdf-message "~&~@<; ~@;registering ~A as ~A~@:>~%" system name)
  (setf (gethash (coerce-name name) *defined-systems*)
        (cons (get-universal-time) system)))


;;;; -------------------------------------------------------------------------
;;;; Finding components

(defmethod find-component ((module module) name &optional version)
  (if (slot-boundp module 'components)
      (let ((m (find name (module-components module)
                     :test #'equal :key #'component-name)))
        (if (and m (version-satisfies m version)) m))))


;;; a component with no parent is a system
(defmethod find-component ((module (eql nil)) name &optional version)
  (declare (ignorable module))
  (let ((m (find-system name nil)))
    (if (and m (version-satisfies m version)) m)))

;;; component subclasses

(defclass source-file (component) ())

(defclass cl-source-file (source-file) ())
(defclass c-source-file (source-file) ())
(defclass java-source-file (source-file) ())
(defclass static-file (source-file) ())
(defclass doc-file (static-file) ())
(defclass html-file (doc-file) ())

(defmethod source-file-type ((component module) (s module)) :directory)
(defmethod source-file-type ((c cl-source-file) (s module)) "lisp")
(defmethod source-file-type ((c c-source-file) (s module)) "c")
(defmethod source-file-type ((c java-source-file) (s module)) "java")
(defmethod source-file-type ((c html-file) (s module)) "html")
(defmethod source-file-type ((c static-file) (s module)) nil)

(defun merge-component-name-type (name &key type defaults)
  ;; The defaults are required notably because they provide the default host
  ;; to the below make-pathname, which may crucially matter to people using
  ;; merge-pathnames with non-default hosts,  e.g. for logical-pathnames.
  ;; NOTE that the host and device slots will be taken from the defaults,
  ;; but that should only matter if you either (a) use absolute pathnames, or
  ;; (b) later merge relative pathnames with CL:MERGE-PATHNAMES instead of
  ;; ASDF:MERGE-PATHNAMES*
  (etypecase name
    (pathname
     name)
    (symbol
     (merge-component-name-type (string-downcase name) :type type :defaults defaults))
    (string
     (multiple-value-bind (relative path filename)
         (component-name-to-pathname-components name (eq type :directory))
       (multiple-value-bind (name type)
           (cond
             ((or (eq type :directory) (null filename))
              (values nil nil))
             (type
              (values filename type))
             (t
              (split-name-type filename)))
         (let* ((defaults (pathname (or defaults *default-pathname-defaults*)))
                (host (pathname-host defaults))
                (device (pathname-device defaults)))
           (make-pathname :directory `(,relative ,@path)
                          :name name :type type
                          :host host :device device)))))))

(defmethod component-relative-pathname ((component component))
  (merge-component-name-type
   (or (slot-value component 'relative-pathname)
       (component-name component))
   :type (source-file-type component (component-system component))
   :defaults (let ((parent (component-parent component)))
               (and parent (component-pathname parent)))))


;;;; -------------------------------------------------------------------------
;;;; Operations

;;; one of these is instantiated whenever #'operate is called

(defclass operation ()
  (
   ;; what is the TYPE of this slot?  seems like it should be boolean,
   ;; but TRAVERSE checks to see if it's a list of component names...
   ;; [2010/02/07:rpg]
   (forced :initform nil :initarg :force :accessor operation-forced)
   (original-initargs :initform nil :initarg :original-initargs
                      :accessor operation-original-initargs)
   (visited-nodes :initform nil :accessor operation-visited-nodes)
   (visiting-nodes :initform nil :accessor operation-visiting-nodes)
   (parent :initform nil :initarg :parent :accessor operation-parent)))

(defmethod print-object ((o operation) stream)
  (print-unreadable-object (o stream :type t :identity t)
    (ignore-errors
      (prin1 (operation-original-initargs o) stream))))

(defmethod shared-initialize :after ((operation operation) slot-names
                                     &key force
                                     &allow-other-keys)
  (declare (ignorable operation slot-names force))
  ;; empty method to disable initarg validity checking
  )

(defun node-for (o c)
  (cons (class-name (class-of o)) c))

(defmethod operation-ancestor ((operation operation))
  (aif (operation-parent operation)
       (operation-ancestor it)
       operation))


(defun make-sub-operation (c o dep-c dep-o)
  "C is a component, O is an operation, DEP-C is another
component, and DEP-O, confusingly enough, is an operation
class specifier, not an operation."
  (let* ((args (copy-list (operation-original-initargs o)))
         (force-p (getf args :force)))
    ;; note explicit comparison with T: any other non-NIL force value
    ;; (e.g. :recursive) will pass through
    (cond ((and (null (component-parent c))
                (null (component-parent dep-c))
                (not (eql c dep-c)))
           (when (eql force-p t)
             (setf (getf args :force) nil))
           (apply #'make-instance dep-o
                  :parent o
                  :original-initargs args args))
          ((subtypep (type-of o) dep-o)
           o)
          (t
           (apply #'make-instance dep-o
                  :parent o :original-initargs args args)))))


(defmethod visit-component ((o operation) (c component) data)
  (unless (component-visited-p o c)
    (push (cons (node-for o c) data)
          (operation-visited-nodes (operation-ancestor o)))))

(defmethod component-visited-p ((o operation) (c component))
  (assoc (node-for o c)
         (operation-visited-nodes (operation-ancestor o))
         :test 'equal))

(defmethod (setf visiting-component) (new-value operation component)
  ;; MCL complains about unused lexical variables
  (declare (ignorable new-value operation component)))

(defmethod (setf visiting-component) (new-value (o operation) (c component))
  (let ((node (node-for o c))
        (a (operation-ancestor o)))
    (if new-value
        (pushnew node (operation-visiting-nodes a) :test 'equal)
        (setf (operation-visiting-nodes a)
              (remove node  (operation-visiting-nodes a) :test 'equal)))))

(defmethod component-visiting-p ((o operation) (c component))
  (let ((node (node-for o c)))
    (member node (operation-visiting-nodes (operation-ancestor o))
            :test 'equal)))

(defmethod component-depends-on ((op-spec symbol) (c component))
  (component-depends-on (make-instance op-spec) c))

(defmethod component-depends-on ((o operation) (c component))
  (cdr (assoc (class-name (class-of o))
              (component-in-order-to c))))

(defmethod component-self-dependencies ((o operation) (c component))
  (let ((all-deps (component-depends-on o c)))
    (remove-if-not (lambda (x)
                     (member (component-name c) (cdr x) :test #'string=))
                   all-deps)))

(defmethod input-files ((operation operation) (c component))
  (let ((parent (component-parent c))
        (self-deps (component-self-dependencies operation c)))
    (if self-deps
        (mapcan (lambda (dep)
                  (destructuring-bind (op name) dep
                    (output-files (make-instance op)
                                  (find-component parent name))))
                self-deps)
        ;; no previous operations needed?  I guess we work with the
        ;; original source file, then
        (list (component-pathname c)))))

(defmethod input-files ((operation operation) (c module)) nil)

(defmethod operation-done-p ((o operation) (c component))
  (let ((out-files (output-files o c))
        (in-files (input-files o c))
        (op-time (gethash (type-of o) (component-operation-times c))))
    (flet ((earliest-out ()
             (reduce #'min (mapcar #'safe-file-write-date out-files)))
           (latest-in ()
             (reduce #'max (mapcar #'safe-file-write-date in-files))))
      (cond
        ((and (not in-files) (not out-files))
         ;; arbitrary decision: an operation that uses nothing to
         ;; produce nothing probably isn't doing much.
         ;; e.g. operations on systems, modules that have no immediate action,
         ;; but are only meaningful through traversed dependencies
         t)
        ((not out-files)
         ;; an operation without output-files is probably meant
         ;; for its side-effects in the current image,
         ;; assumed to be idem-potent,
         ;; e.g. LOAD-OP or LOAD-SOURCE-OP of some CL-SOURCE-FILE.
         (and op-time
              (>= op-time (latest-in))))
        ((not in-files)
         ;; an operation without output-files and no input-files
         ;; is probably meant for its side-effects on the file-system,
         ;; assumed to have to be done everytime.
         ;; (I don't think there is any such case in ASDF unless extended)
         nil)
        (t
         ;; an operation with both input and output files is assumed
         ;; as computing the latter from the former,
         ;; assumed to have been done if the latter are all older
         ;; than the former.
         ;; e.g. COMPILE-OP of some CL-SOURCE-FILE.
         (and
          (every #'probe-file in-files)
          (every #'probe-file out-files)
          (and (> (earliest-out) (latest-in)))))))))


;;; So you look at this code and think "why isn't it a bunch of
;;; methods".  And the answer is, because standard method combination
;;; runs :before methods most->least-specific, which is back to front
;;; for our purposes.

(defvar *forcing* nil
  "This dynamically-bound variable is used to force operations in
recursive calls to traverse.")

(defmethod traverse ((operation operation) (c component))
  (let ((forced nil))                   ;return value -- everyone side-effects onto this
    (labels ((%do-one-dep (required-op required-c required-v)
               ;; returns a partial plan that results from performing required-op
               ;; on required-c, possibly with a required-vERSION
               (let* ((dep-c (or (find-component
                                  (component-parent c)
                                  ;; XXX tacky.  really we should build the
                                  ;; in-order-to slot with canonicalized
                                  ;; names instead of coercing this late
                                  (coerce-name required-c) required-v)
                                 (if required-v
                                     (error 'missing-dependency-of-version
                                            :required-by c
                                            :version required-v
                                            :requires required-c)
                                     (error 'missing-dependency
                                            :required-by c
                                            :requires required-c))))
                      (op (make-sub-operation c operation dep-c required-op)))
                 (traverse op dep-c)))
             (do-one-dep (required-op required-c required-v)
               ;; this function is a thin, error-handling wrapper around
               ;; %do-one-dep.  Returns a partial plan per that function.
               (loop
                 (restart-case
                     (return (%do-one-dep required-op required-c required-v))
                   (retry ()
                     :report (lambda (s)
                               (format s "~@<Retry loading component ~S.~@:>"
                                       required-c))
                     :test
                     (lambda (c)
#|
                        (print (list :c1 c (typep c 'missing-dependency)))
                        (when (typep c 'missing-dependency)
                          (print (list :c2 (missing-requires c) required-c
                                       (equalp (missing-requires c)
                                               required-c))))
|#
                       (or (null c)
                           (and (typep c 'missing-dependency)
                                (equalp (missing-requires c)
                                        required-c))))))))
             (do-dep (op dep)
               ;; type of arguments uncertain:  op seems to at least potentially be a
               ;; symbol, rather than an operation
               ;; dep is either a list of component names (?) or (we hope) a single
               ;; component name.
               ;; handle a single dependency, returns nothing of interest --- side-
               ;; effects onto the FORCED variable, which is scoped over TRAVERSE
               (cond ((eq op 'feature)
                      (or (member (car dep) *features*)
                          (error 'missing-dependency
                                 :required-by c
                                 :requires (car dep))))
                     (t
                      (dolist (d dep)
                        ;; structured dependencies --- this parses keywords
                        ;; the keywords could be broken out and cleanly (extensibly)
                        ;; processed by EQL methods, but for the pervasive side-effecting
                        ;; onto FORCED
                        (cond ((consp d)
                               (cond ((string-equal
                                       (symbol-name (first d))
                                       "VERSION")
                                      (appendf
                                       forced
                                       (do-one-dep op (second d) (third d))))
                                     ;; this particular subform is not documented, indeed
                                     ;; clashes with the documentation, since it assumes a
                                     ;; third component
                                     ((and (string-equal
                                            (symbol-name (first d))
                                            "FEATURE")
                                           (find (second d) *features*
                                                 :test 'string-equal))
                                      (appendf
                                       forced
                                       (do-one-dep op (second d) (third d))))
                                     (t
                                      (error "Bad dependency ~a.  Dependencies must be (:version <version>), (:feature <feature> [version]), or a name" d))))
                              (t
                               (appendf forced (do-one-dep op d nil)))))))))
      (aif (component-visited-p operation c)
           (return-from traverse
             (if (cdr it) (list (cons 'pruned-op c)) nil)))
      ;; dependencies
      (if (component-visiting-p operation c)
          (error 'circular-dependency :components (list c)))
      (setf (visiting-component operation c) t)
      (unwind-protect
          (progn
            ;; first we check and do all the dependencies for the
            ;; module.  Operations planned in this loop will show up
            ;; in the contents of the FORCED variable, and are consumed
            ;; downstream (watch out for the shadowing FORCED variable
            ;; around the DOLIST below!)
            (let ((*forcing* nil))
              ;; upstream dependencies are never forced to happen just because
              ;; the things that depend on them are....
              (loop :for (required-op . deps) :in
                                              (component-depends-on operation c)
                    :do (do-dep required-op deps)))
            ;; constituent bits
            (let ((module-ops
                   (when (typep c 'module)
                     (let ((at-least-one nil)
                           (forced nil)
                           ;; this is set based on the results of the
                           ;; dependencies and whether we are in the
                           ;; context of a *forcing* call...
                           (must-operate (or *forcing*
                                             ;; inter-system dependencies do NOT trigger
                                             ;; building components
                                             (and
                                              (not (typep c 'system))
                                              forced)))
                           (error nil))
                       (dolist (kid (module-components c))
                           (handler-case
                               (let ((*forcing* must-operate))
                                 (appendf forced (traverse operation kid)))
                             (missing-dependency (condition)
                               (when (eq (module-if-component-dep-fails c)
                                       :fail)
                                   (error condition))
                               (setf error condition))
                             (:no-error (c)
                               (declare (ignore c))
                               (setf at-least-one t))))
                       (when (and (eq (module-if-component-dep-fails c)
                                      :try-next)
                                  (not at-least-one))
                         (error error))
                       forced))))
              ;; now the thing itself
              ;; the test here is a bit oddly written.  FORCED here doesn't
              ;; mean that this operation is forced on this component, but that
              ;; something upstream of this component has been forced.
              (when (or forced module-ops
                        *forcing*
                        (not (operation-done-p operation c))
                        (let ((f (operation-forced
                                  (operation-ancestor operation))))
                          ;; does anyone fully understand the following condition?
                          ;; if so, please add a comment to explain it...
                          (and f (or (not (consp f))
                                     (member (component-name
                                              (operation-ancestor operation))
                                             (mapcar #'coerce-name f)
                                             ;; this was string=, but for the benefit
                                             ;; of mlisp, we use string-equal for this
                                             ;; purpose.
                                             :test #'string-equal)))))
                (let ((do-first (cdr (assoc (class-name (class-of operation))
                                            (component-do-first c)))))
                  (loop :for (required-op . deps) :in do-first
                        :do (do-dep required-op deps)))
                (setf forced (append (delete 'pruned-op forced :key #'car)
                                     (delete 'pruned-op module-ops :key #'car)
                                     (list (cons operation c)))))))
        (setf (visiting-component operation c) nil))
      (visit-component operation c (and forced t))
      forced)))


(defmethod perform ((operation operation) (c source-file))
  (sysdef-error
   "~@<required method PERFORM not implemented ~
    for operation ~A, component ~A~@:>"
   (class-of operation) (class-of c)))

(defmethod perform ((operation operation) (c module))
  nil)

(defmethod explain ((operation operation) (component component))
  (asdf-message "~&;;; ~A on ~A~%" operation component))

;;;; -------------------------------------------------------------------------
;;;; compile-op

(defclass compile-op (operation)
  ((proclamations :initarg :proclamations :accessor compile-op-proclamations :initform nil)
   (on-warnings :initarg :on-warnings :accessor operation-on-warnings
                :initform *compile-file-warnings-behaviour*)
   (on-failure :initarg :on-failure :accessor operation-on-failure
               :initform *compile-file-failure-behaviour*)
   (flags :initarg :flags :accessor compile-op-flags
          :initform #-ecl nil #+ecl '(:system-p t))))

(defmethod perform :before ((operation compile-op) (c source-file))
  (map nil #'ensure-directories-exist (output-files operation c)))

#+ecl
(defmethod perform :after ((o compile-op) (c cl-source-file))
  ;; Note how we use OUTPUT-FILES to find the binary locations
  ;; This allows the user to override the names.
  (let* ((input (output-files o c))
         (output (compile-file-pathname (first input) :type :fasl)))
    (c:build-fasl output :lisp-files (remove "fas" input :key #'pathname-type :test #'string=))))

(defmethod perform :after ((operation operation) (c component))
  (setf (gethash (type-of operation) (component-operation-times c))
        (get-universal-time)))

;;; perform is required to check output-files to find out where to put
;;; its answers, in case it has been overridden for site policy
(defmethod perform ((operation compile-op) (c cl-source-file))
  #-:broken-fasl-loader
  (let ((source-file (component-pathname c))
        (output-file (car (output-files operation c))))
    (multiple-value-bind (output warnings-p failure-p)
        (apply #'compile-file source-file :output-file output-file
               (compile-op-flags operation))
      (when warnings-p
        (case (operation-on-warnings operation)
          (:warn (warn
                  "~@<COMPILE-FILE warned while performing ~A on ~A.~@:>"
                  operation c))
          (:error (error 'compile-warned :component c :operation operation))
          (:ignore nil)))
      (when failure-p
        (case (operation-on-failure operation)
          (:warn (warn
                  "~@<COMPILE-FILE failed while performing ~A on ~A.~@:>"
                  operation c))
          (:error (error 'compile-failed :component c :operation operation))
          (:ignore nil)))
      (unless output
        (error 'compile-error :component c :operation operation)))))

(defmethod output-files ((operation compile-op) (c cl-source-file))
  #-:broken-fasl-loader
  (list #-ecl (compile-file-pathname (component-pathname c))
        #+ecl (compile-file-pathname (component-pathname c) :type :object)
        #+ecl (compile-file-pathname (component-pathname c) :type :fasl))
  #+:broken-fasl-loader (list (component-pathname c)))

(defmethod perform ((operation compile-op) (c static-file))
  nil)

(defmethod output-files ((operation compile-op) (c static-file))
  nil)

(defmethod input-files ((op compile-op) (c static-file))
  nil)


;;;; -------------------------------------------------------------------------
;;;; load-op

(defclass basic-load-op (operation) ())

(defclass load-op (basic-load-op) ())

(defmethod perform ((o load-op) (c cl-source-file))
  #-ecl (mapcar #'load (input-files o c))
  #+ecl (loop :for i :in (input-files o c)
          :unless (string= (pathname-type i) "fas")
          :collect (let ((output (compile-file-pathname i)))
                     (load output))))

(defmethod perform around ((o load-op) (c cl-source-file))
  (let ((state :initial))
    (loop :until (or (eq state :success)
                     (eq state :failure)) :do
         (case state
           (:recompiled
            (setf state :failure)
            (call-next-method)
            (setf state :success))
           (:failed-load
            (setf state :recompiled)
            (perform (make-instance 'asdf:compile-op) c))
           (t
            (with-simple-restart
                (try-recompiling "Recompile ~a and try loading it again"
                                  (component-name c))
              (setf state :failed-load)
              (call-next-method)
              (setf state :success)))))))

(defmethod perform around ((o compile-op) (c cl-source-file))
  (let ((state :initial))
    (loop :until (or (eq state :success)
                     (eq state :failure)) :do
         (case state
           (:recompiled
            (setf state :failure)
            (call-next-method)
            (setf state :success))
           (:failed-compile
            (setf state :recompiled)
            (perform (make-instance 'asdf:compile-op) c))
           (t
            (with-simple-restart
                (try-recompiling "Try recompiling ~a"
                                  (component-name c))
              (setf state :failed-compile)
              (call-next-method)
              (setf state :success)))))))

(defmethod perform ((operation load-op) (c static-file))
  nil)

(defmethod operation-done-p ((operation load-op) (c static-file))
  t)

(defmethod output-files ((o operation) (c component))
  nil)

(defmethod component-depends-on ((operation load-op) (c component))
  (cons (list 'compile-op (component-name c))
        (call-next-method)))

;;;; -------------------------------------------------------------------------
;;;; load-source-op

(defclass load-source-op (basic-load-op) ())

(defmethod perform ((o load-source-op) (c cl-source-file))
  (let ((source (component-pathname c)))
    (setf (component-property c 'last-loaded-as-source)
          (and (load source)
               (get-universal-time)))))

(defmethod perform ((operation load-source-op) (c static-file))
  nil)

(defmethod output-files ((operation load-source-op) (c component))
  nil)

;;; FIXME: we simply copy load-op's dependencies.  this is Just Not Right.
(defmethod component-depends-on ((o load-source-op) (c component))
  (let ((what-would-load-op-do (cdr (assoc 'load-op
                                           (component-in-order-to c)))))
    (mapcar (lambda (dep)
              (if (eq (car dep) 'load-op)
                  (cons 'load-source-op (cdr dep))
                  dep))
            what-would-load-op-do)))

(defmethod operation-done-p ((o load-source-op) (c source-file))
  (if (or (not (component-property c 'last-loaded-as-source))
          (> (safe-file-write-date (component-pathname c))
             (component-property c 'last-loaded-as-source)))
      nil t))


;;;; -------------------------------------------------------------------------
;;;; test-op

(defclass test-op (operation) ())

(defmethod perform ((operation test-op) (c component))
  nil)

(defmethod operation-done-p ((operation test-op) (c system))
  "Testing a system is _never_ done."
  nil)

(defmethod component-depends-on :around ((o test-op) (c system))
  (cons `(load-op ,(component-name c)) (call-next-method)))


;;;; -------------------------------------------------------------------------
;;;; Invoking Operations

(defun operate (operation-class system &rest args &key (verbose t) version force
                &allow-other-keys)
  (declare (ignore force))
  (let* ((*package* *package*)
         (*readtable* *readtable*)
         (op (apply #'make-instance operation-class
                    :original-initargs args
                    args))
         (*verbose-out* (if verbose *standard-output* (make-broadcast-stream)))
         (system (if (typep system 'component) system (find-system system))))
    (unless (version-satisfies system version)
      (error 'missing-component-of-version :requires system :version version))
    (let ((steps (traverse op system)))
      (with-compilation-unit ()
        (loop :for (op . component) :in steps :do
          (loop
            (restart-case
                (progn (perform op component)
                       (return))
              (retry ()
                :report
                (lambda (s)
                  (format s "~@<Retry performing ~S on ~S.~@:>"
                          op component)))
              (accept ()
                :report
                (lambda (s)
                  (format s "~@<Continue, treating ~S on ~S as ~
                                   having been successful.~@:>"
                          op component))
                (setf (gethash (type-of op)
                               (component-operation-times component))
                      (get-universal-time))
                (return)))))))
    op))

(defun oos (operation-class system &rest args &key force (verbose t) version
            &allow-other-keys)
  (declare (ignore force verbose version))
  (apply #'operate operation-class system args))

(let ((operate-docstring
  "Operate does three things:

1. It creates an instance of `operation-class` using any keyword parameters
as initargs.
2. It finds the  asdf-system specified by `system` (possibly loading
it from disk).
3. It then calls `traverse` with the operation and system as arguments

The traverse operation is wrapped in `with-compilation-unit` and error
handling code. If a `version` argument is supplied, then operate also
ensures that the system found satisfies it using the `version-satisfies`
method.

Note that dependencies may cause the operation to invoke other
operations on the system or its components: the new operations will be
created with the same initargs as the original one.
"))
  (setf (documentation 'oos 'function)
        (format nil
                "Short for _operate on system_ and an alias for the OPERATE function. ~&~&~a"
                operate-docstring))
  (setf (documentation 'operate 'function)
        operate-docstring))

(defun load-system (system &rest args &key force (verbose t) version
                    &allow-other-keys)
  "Shorthand for `(operate 'asdf:load-op system)`. See OPERATE for
details."
  (declare (ignore force verbose version))
  (apply #'operate 'load-op system args))

(defun compile-system (system &rest args &key force (verbose t) version
                       &allow-other-keys)
  "Shorthand for `(operate 'asdf:compile-op system)`. See OPERATE
for details."
  (declare (ignore force verbose version))
  (apply #'operate 'compile-op system args))

(defun test-system (system &rest args &key force (verbose t) version
                    &allow-other-keys)
  "Shorthand for `(operate 'asdf:test-op system)`. See OPERATE for
details."
  (declare (ignore force verbose version))
  (apply #'operate 'test-op system args))

;;;; -------------------------------------------------------------------------
;;;; Defsystem

(defun determine-system-pathname (pathname pathname-supplied-p)
  ;; called from the defsystem macro.
  ;; the pathname of a system is either
  ;; 1. the one supplied,
  ;; 2. derived from the *load-truename* (see below), or
  ;; 3. taken from *default-pathname-defaults*
  ;;
  ;; if using *load-truename*, then we also deal with whether or not
  ;; to resolve symbolic links. If not resolving symlinks, then we use
  ;; *load-pathname* instead of *load-truename* since in some
  ;; implementations, the latter has *already resolved it.
  (or (and pathname-supplied-p pathname)
      (when *load-pathname*
        (pathname-directory-pathname
         (if *resolve-symlinks*
             (resolve-symlinks *load-truename*)
             *load-pathname*)))
      *default-pathname-defaults*))

(defmacro defsystem (name &body options)
  (destructuring-bind (&key (pathname nil pathname-arg-p) (class 'system)
                            &allow-other-keys)
      options
    (let ((component-options (remove-keyword :class options)))
      `(progn
         ;; system must be registered before we parse the body, otherwise
         ;; we recur when trying to find an existing system of the same name
         ;; to reuse options (e.g. pathname) from
         (let ((s (system-registered-p ',name)))
           (cond ((and s (eq (type-of (cdr s)) ',class))
                  (setf (car s) (get-universal-time)))
                 (s
                  (change-class (cdr s) ',class))
                 (t
                  (register-system (quote ,name)
                                   (make-instance ',class :name ',name))))
           (%set-system-source-file *load-truename*
                                    (cdr (system-registered-p ',name))))
         (parse-component-form
          nil (apply
               #'list
               :module (coerce-name ',name)
               :pathname
               ,(determine-system-pathname pathname pathname-arg-p)
               ',component-options))))))


(defun class-for-type (parent type)
  (let* ((extra-symbols (list (find-symbol (symbol-name type) *package*)
                              (find-symbol (symbol-name type)
                                           (load-time-value
                                            (package-name :asdf)))))
         (class (dolist (symbol (if (keywordp type)
                                    extra-symbols
                                    (cons type extra-symbols)))
                  (when (and symbol
                             (find-class symbol nil)
                             (subtypep symbol 'component))
                    (return (find-class symbol))))))
    (or class
        (and (eq type :file)
             (or (module-default-component-class parent)
                 (find-class 'cl-source-file)))
        (sysdef-error "~@<don't recognize component type ~A~@:>" type))))

(defun maybe-add-tree (tree op1 op2 c)
  "Add the node C at /OP1/OP2 in TREE, unless it's there already.
Returns the new tree (which probably shares structure with the old one)"
  (let ((first-op-tree (assoc op1 tree)))
    (if first-op-tree
        (progn
          (aif (assoc op2 (cdr first-op-tree))
               (if (find c (cdr it))
                   nil
                   (setf (cdr it) (cons c (cdr it))))
               (setf (cdr first-op-tree)
                     (acons op2 (list c) (cdr first-op-tree))))
          tree)
        (acons op1 (list (list op2 c)) tree))))

(defun union-of-dependencies (&rest deps)
  (let ((new-tree nil))
    (dolist (dep deps)
      (dolist (op-tree dep)
        (dolist (op  (cdr op-tree))
          (dolist (c (cdr op))
            (setf new-tree
                  (maybe-add-tree new-tree (car op-tree) (car op) c))))))
    new-tree))


(defvar *serial-depends-on*)

(defun sysdef-error-component (msg type name value)
  (sysdef-error (concatenate 'string msg
                             "~&The value specified for ~(~A~) ~A is ~W")
                type name value))

(defun check-component-input (type name weakly-depends-on
                              depends-on components in-order-to)
  "A partial test of the values of a component."
  (unless (listp depends-on)
    (sysdef-error-component ":depends-on must be a list."
                            type name depends-on))
  (unless (listp weakly-depends-on)
    (sysdef-error-component ":weakly-depends-on must be a list."
                            type name weakly-depends-on))
  (unless (listp components)
    (sysdef-error-component ":components must be NIL or a list of components."
                            type name components))
  (unless (and (listp in-order-to) (listp (car in-order-to)))
    (sysdef-error-component ":in-order-to must be NIL or a list of components."
                            type name in-order-to)))

(defun %remove-component-inline-methods (component)
  (dolist (name +asdf-methods+)
    (map ()
         ;; this is inefficient as most of the stored
         ;; methods will not be for this particular gf n
         ;; But this is hardly performance-critical
         (lambda (m)
           (remove-method (symbol-function name) m))
         (component-inline-methods component)))
  ;; clear methods, then add the new ones
  (setf (component-inline-methods component) nil))

(defun %define-component-inline-methods (ret rest)
  (dolist (name +asdf-methods+)
    (let ((keyword (intern (symbol-name name) :keyword)))
      (loop :for data = rest :then (cddr data)
        :for key = (first data)
        :for value = (second data)
        :while data
        :when (eq key keyword) :do
        (destructuring-bind (op qual (o c) &body body) value
          (pushnew
           (eval `(defmethod ,name ,qual ((,o ,op) (,c (eql ,ret)))
                             ,@body))
           (component-inline-methods ret)))))))

(defun %refresh-component-inline-methods (component rest)
  (%remove-component-inline-methods component)
  (%define-component-inline-methods component rest))

(defun parse-component-form (parent options)

  (destructuring-bind
        (type name &rest rest &key
              ;; the following list of keywords is reproduced below in the
              ;; remove-keys form.  important to keep them in sync
              components pathname default-component-class
              perform explain output-files operation-done-p
              weakly-depends-on
              depends-on serial in-order-to
              ;; list ends
              &allow-other-keys) options
    (declare (ignorable perform explain output-files operation-done-p))
    (check-component-input type name weakly-depends-on depends-on components in-order-to)

    (when (and parent
               (find-component parent name)
               ;; ignore the same object when rereading the defsystem
               (not
                (typep (find-component parent name)
                       (class-for-type parent type))))
      (error 'duplicate-names :name name))

    (let* ((other-args (remove-keys
                        '(components pathname default-component-class
                          perform explain output-files operation-done-p
                          weakly-depends-on
                          depends-on serial in-order-to)
                        rest))
           (ret
            (or (find-component parent name)
                (make-instance (class-for-type parent type)))))
      (when weakly-depends-on
        (setf depends-on (append depends-on (remove-if (complement #'find-system) weakly-depends-on))))
      (when (boundp '*serial-depends-on*)
        (setf depends-on
              (concatenate 'list *serial-depends-on* depends-on)))
      (apply #'reinitialize-instance ret
             :name (coerce-name name)
             :pathname pathname
             :parent parent
             other-args)
      (when (typep ret 'module)
        (setf (module-default-component-class ret)
              (or default-component-class
                  (and (typep parent 'module)
                       (module-default-component-class parent))))
        (let ((*serial-depends-on* nil))
          (setf (module-components ret)
                (loop :for c-form :in components
                  :for c = (parse-component-form ret c-form)
                  :collect c
                  :if serial
                  :do (push (component-name c) *serial-depends-on*))))

        ;; check for duplicate names
        (let ((name-hash (make-hash-table :test #'equal)))
          (loop :for c in (module-components ret) :do
            (if (gethash (component-name c)
                         name-hash)
                (error 'duplicate-names
                       :name (component-name c))
                (setf (gethash (component-name c)
                               name-hash)
                      t)))))

      (setf (component-in-order-to ret)
            (union-of-dependencies
             in-order-to
             `((compile-op (compile-op ,@depends-on))
               (load-op (load-op ,@depends-on))))
            (component-do-first ret) `((compile-op (load-op ,@depends-on))))

      (%refresh-component-inline-methods ret rest)

      ret)))

;;;; ---------------------------------------------------------------------------
;;;; run-shell-command
;;;;
;;;; run-shell-command functions for other lisp implementations will be
;;;; gratefully accepted, if they do the same thing.
;;;; If the docstring is ambiguous, send a bug report.
;;;;
;;;; We probably should move this functionality to its own system and deprecate
;;;; use of it from the asdf package. However, this would break unspecified
;;;; existing software, so until a clear alternative exists, we can't deprecate
;;;; it, and even after it's been deprecated, we will support it for a few
;;;; years so everyone has time to migrate away from it. -- fare 2009-12-01

(defun run-shell-command (control-string &rest args)
  "Interpolate `args` into `control-string` as if by `format`, and
synchronously execute the result using a Bourne-compatible shell, with
output to `*verbose-out*`.  Returns the shell's exit code."
  (let ((command (apply #'format nil control-string args)))
    (asdf-message "; $ ~A~%" command)
    #+sbcl
    (sb-ext:process-exit-code
     (apply #'sb-ext:run-program
            #+win32 "sh" #-win32 "/bin/sh"
            (list  "-c" command)
            :input nil :output *verbose-out*
            #+win32 '(:search t) #-win32 nil))

    #+(or cmu scl)
    (ext:process-exit-code
     (ext:run-program
      "/bin/sh"
      (list  "-c" command)
      :input nil :output *verbose-out*))

    #+allegro
    ;; will this fail if command has embedded quotes - it seems to work
    (multiple-value-bind (stdout stderr exit-code)
        (excl.osi:command-output
         (format nil "~a -c \"~a\""
                 #+mswindows "sh" #-mswindows "/bin/sh" command)
         :input nil :whole nil
         #+mswindows :show-window #+mswindows :hide)
      (format *verbose-out* "~{~&; ~a~%~}~%" stderr)
      (format *verbose-out* "~{~&; ~a~%~}~%" stdout)
      exit-code)

    #+lispworks
    (system:call-system-showing-output
     command
     :shell-type "/bin/sh"
     :show-cmd nil
     :prefix ""
     :output-stream *verbose-out*)

    #+clisp                     ;XXX not exactly *verbose-out*, I know
    (ext:run-shell-command  command :output :terminal :wait t)

    #+openmcl
    (nth-value 1
               (ccl:external-process-status
                (ccl:run-program "/bin/sh" (list "-c" command)
                                 :input nil :output *verbose-out*
                                 :wait t)))

    #+ecl ;; courtesy of Juan Jose Garcia Ripoll
    (si:system command)

    #-(or openmcl clisp lispworks allegro scl cmu sbcl ecl)
    (error "RUN-SHELL-COMMAND not implemented for this Lisp")
    ))

;;;; ---------------------------------------------------------------------------
;;;; system-relative-pathname

(defmethod system-source-file ((system-name t))
  (system-source-file (find-system system-name)))

(defun system-source-directory (system-name)
  (make-pathname :name nil
                 :type nil
                 :defaults (system-source-file system-name)))

(defun relativize-directory (directory)
  (if (eq (car directory) :absolute)
      (cons :relative (cdr directory))
      directory))

(defun relativize-pathname-directory (pathspec)
  (let ((p (pathname pathspec)))
    (make-pathname
     :directory (relativize-directory (pathname-directory p))
     :defaults p)))

(defun system-relative-pathname (system pathname &key name type)
  (let ((directory (pathname-directory pathname)))
    (merge-pathnames*
     (make-pathname :name (or name (pathname-name pathname))
                    :type (or type (pathname-type pathname))
                    :directory (relativize-directory directory))
     (system-source-directory system))))


;;; ---------------------------------------------------------------------------
;;; implementation-identifier
;;;
;;; produce a string to identify current implementation.
;;; Initially stolen from SLIME's SWANK, hacked since.

(defparameter *implementation-features*
  '(:allegro :lispworks :sbcl :clozure :digitool :cmu :clisp
    :corman :cormanlisp :armedbear :gcl :ecl :scl))

(defparameter *os-features*
  '((:windows :mswindows :win32 :mingw32)
    (:solaris :sunos)
    :macosx :darwin :apple
    :freebsd :netbsd :openbsd :bsd
    :linux :unix))

(defparameter *architecture-features*
  '((:x86-64 :amd64 :x86_64 :x8664-target)
    (:x86 :i686 :i586 :pentium3 :i486 :i386 :pc386 :iapx386 :x8632-target :pentium4)
    :hppa64 :hppa :ppc64 (:ppc32 :ppc :powerpc) :sparc64 :sparc))

(defun lisp-version-string ()
  (let ((s (lisp-implementation-version)))
    (declare (ignorable s))
    #+(or scl sbcl ecl armedbear cormanlisp mcl) s
    #+cmu (substitute #\- #\/ s)
    #+clozure (format nil "~d.~d~@[-~d~]"
                      ccl::*openmcl-major-version*
                      ccl::*openmcl-minor-version*
                      #+ppc64-target 64
                      #-ppc64-target nil)
    #+lispworks (format nil "~A~@[~A~]" s
                        (when (member :lispworks-64bit *features*) "-64bit"))
    #+allegro (format nil
                      "~A~A~A~A"
                      excl::*common-lisp-version-number*
                      ;; ANSI vs MoDeRn - thanks to Robert Goldman and Charley Cox
                      (if (eq excl:*current-case-mode*
                              :case-sensitive-lower) "M" "A")
                      ;; Note if not using International ACL
                      ;; see http://www.franz.com/support/documentation/8.1/doc/operators/excl/ics-target-case.htm
                      (excl:ics-target-case
                       (:-ics "8")
                       (:+ics ""))
                      (if (member :64bit *features*) "-64bit" ""))
    #+(or clisp gcl) (subseq s 0 (position #\space s))
    #+digitool (subseq s 8)))

(defun first-feature (features)
  (labels
      ((fp (thing)
         (etypecase thing
           (symbol
            (let ((feature (find thing *features*)))
              (when feature (return-from fp feature))))
           ;; allows features to be lists of which the first
           ;; member is the "main name", the rest being aliases
           (cons
            (dolist (subf thing)
              (when (find subf *features*) (return-from fp (first thing))))))
         nil))
    (loop :for f :in features
      :when (fp f) :return :it)))

(defun implementation-type ()
  (first-feature *implementation-features*))

(defun implementation-identifier ()
  (labels
      ((maybe-warn (value fstring &rest args)
         (cond (value)
               (t (apply #'warn fstring args)
                  "unknown"))))
    (let ((lisp (maybe-warn (implementation-type)
                            "No implementation feature found in ~a."
                            *implementation-features*))
          (os   (maybe-warn (first-feature *os-features*)
                            "No os feature found in ~a." *os-features*))
          (arch (maybe-warn (first-feature *architecture-features*)
                            "No architecture feature found in ~a."
                            *architecture-features*))
          (version (maybe-warn (lisp-version-string)
                               "Don't know how to get Lisp ~
                                          implementation version.")))
      (substitute-if
       #\_ (lambda (x) (find x " /:\\(){}[]$#`'\""))
       (format nil "~(~@{~a~^-~}~)" lisp version os arch)))))



;;; ---------------------------------------------------------------------------
;;; Generic support for configuration files
(defun user-configuration-directory ()
  (merge-pathnames* #p".config/" (user-homedir-pathname)))
(defun system-configuration-directory ()
  #p"/etc/")

(defun configuration-inheritance-directive-p (x)
  (let ((kw '(:inherit-configuration :ignore-inherited-configuration)))
    (or (member x kw)
        (and (length=n-p x 1) (member (car x) kw)))))

(defun validate-configuration-form (form tag directive-validator
                                    &optional (description tag))
  (unless (and (consp form) (eq (car form) tag))
    (error "Error: Form doesn't specify ~A ~S~%" description form))
  (loop :with inherit = 0
    :for directive :in (cdr form) :do
    (if (configuration-inheritance-directive-p directive)
        (incf inherit)
        (funcall directive-validator directive))
    :finally
    (unless (= inherit 1)
      (error "One and only one of ~S or ~S is required"
             :inherit-configuration :ignore-inherited-configuration)))
  form)

(defun validate-configuration-file (file validator description)
  (let ((forms (read-file-forms file)))
    (unless (length=n-p forms 1)
      (error "One and only one form allowed for ~A. Got: ~S~%" description forms))
    (funcall validator (car forms))))

(defun validate-configuration-directory (directory tag validator)
  (let ((files (sort (ignore-errors
                       (directory (make-pathname :name :wild :type :wild :defaults directory)
                                  #+sbcl :resolve-symlinks #+sbcl nil))
                     #'string< :key #'namestring)))
    `(,tag
      ,@(loop :for file :in files :append
          (mapcar validator (read-file-forms file)))
      :inherit-configuration)))


;;; ---------------------------------------------------------------------------
;;; asdf-output-translations
;;;
;;; this code is heavily inspired from
;;; asdf-binary-translations, common-lisp-controller and cl-launch.
;;; ---------------------------------------------------------------------------

(defvar *output-translations* ()
  "Either NIL (for uninitialized), or a list of one element,
said element itself being a sorted list of mappings.
Each mapping is a pair of a source pathname and destination pathname,
and the order is by decreasing length of namestring of the source pathname.")

(defvar *user-cache* '(:home ".cache" "common-lisp" :implementation))
(defvar *system-cache* '(:root "var" "cache" "common-lisp" :uid :implementation))

(defun output-translations ()
  (car *output-translations*))

(defun (setf output-translations) (x)
  (setf *output-translations*
        (list
         (stable-sort (copy-list x) #'>
                      :key (lambda (x) (length (pathname-directory (car x))))))))

(defun output-translations-initialized-p ()
  (and *output-translations* t))

(defun clear-output-translations ()
  "Undoes any initialization of the output translations.
You might want to call that before you dump an image that would be resumed
with a different configuration, so the configuration would be re-read then."
  (setf *output-translations* '())
  (values))

(defparameter *wild-path*
  (make-pathname :directory '(:relative :wild-inferiors)
                 :name :wild :type :wild :version nil))

(defparameter *wild-asd*
  (make-pathname :directory '(:relative :wild-inferiors)
                 :name :wild :type "asd" :version nil))

(defun wilden (path)
  (merge-pathnames* *wild-path* path))

(defun resolve-absolute-location-component (x wildenp)
  (let* ((r
          (etypecase x
            (pathname x)
            (string (ensure-directory-pathname x))
            ((eql :home) (user-homedir-pathname))
            ((eql :user-cache) (resolve-location *user-cache* nil))
            ((eql :system-cache) (resolve-location *system-cache* nil))
            ((eql :current-directory) (truenamize *default-pathname-defaults*))
            ((eql :root) (make-pathname :directory '(:absolute)))))
         (s (if (and wildenp (not (pathnamep x)))
                (wilden r)
                r)))
    (unless (absolute-pathname-p s)
      (error "Not an absolute pathname ~S" s))
    s))

(defun resolve-relative-location-component (super x &optional wildenp)
  (let* ((r (etypecase x
              (pathname x)
              (string x)
              ((eql :current-directory)
               (relativize-pathname-directory
                (truenamize *default-pathname-defaults*)))
              ((eql :implementation) (implementation-identifier))
              ((eql :implementation-type) (string-downcase (implementation-type)))
              ((eql :uid) (princ-to-string (get-uid)))))
         (d (if (pathnamep x) r (ensure-directory-pathname r)))
         (s (if (and wildenp (not (pathnamep x)))
                (wilden d)
                d)))
    (when (and (absolute-pathname-p s) (not (pathname-match-p s (wilden super))))
      (error "pathname ~S is not relative to ~S" s super))
    (merge-pathnames* s super)))

(defun resolve-location (x &optional wildenp)
  (if (atom x)
      (resolve-absolute-location-component x wildenp)
      (loop :with path = (resolve-absolute-location-component (car x) nil)
        :for (component . morep) :on (cdr x)
        :do (setf path (resolve-relative-location-component
                        path component (and wildenp (not morep))))
        :finally (return path))))

(defun location-designator-p (x)
  (flet ((componentp (c) (typep c '(or string pathname keyword))))
    (or (componentp x) (and (consp x) (every #'componentp x)))))

(defun validate-output-translations-directive (directive)
  (unless
      (or (member directive '(:inherit-configuration
                              :ignore-inherited-configuration
                              :enable-user-cache :disable-cache))
          (and (consp directive)
               (or (and (length=n-p directive 2)
                        (or (and (eq (first directive) :include)
                                 (typep (second directive) '(or string pathname null)))
                            (and (location-designator-p (first directive))
                                 (or (location-designator-p (second directive))
                                     (null (second directive))))))
                   (and (length=n-p directive 1)
                        (location-designator-p (first directive))))))
    (error "Invalid directive ~S~%" directive))
  directive)

(defun validate-output-translations-form (form)
  (validate-configuration-form
   form
   :output-translations
   'validate-output-translations-directive
   "output translations"))

(defun validate-output-translations-file (file)
  (validate-configuration-file
   file 'validate-output-translations-form "output translations"))

(defun validate-output-translations-directory (directory)
  (validate-configuration-directory
   directory :output-translations 'validate-output-translations-directive))

(defun parse-output-translations-string (string)
  (cond
    ((or (null string) (equal string ""))
     '(:output-translations :inherit-configuration))
    ((not (stringp string))
     (error "environment string isn't: ~S" string))
    ((find (char string 0) "\"(")
     (validate-output-translations-form (read-from-string string)))
    (t
     (loop
      :with inherit = nil
      :with directives = ()
      :with start = 0
      :with end = (length string)
      :with source = nil
      :for i = (or (position #\: string :start start) end) :do
      (let ((s (subseq string start i)))
        (cond
          (source
           (push (list source (if (equal "" s) nil s)) directives)
           (setf source nil))
          ((equal "" s)
           (when inherit
             (error "only one inherited configuration allowed: ~S" string))
           (setf inherit t)
           (push :inherit-configuration directives))
          (t
           (setf source s)))
        (setf start (1+ i))
        (when (>= start end)
          (when source
            (error "Uneven number of components in source to destination mapping ~S" string))
          (unless inherit
            (push :ignore-inherited-configuration directives))
          (return `(:output-translations ,@(nreverse directives)))))))))

(defparameter *default-output-translations*
  '(implementation-output-translations
    user-output-translations-pathname
    user-output-translations-directory-pathname
    system-output-translations-pathname
    system-output-translations-directory-pathname))

(defparameter *implementation-output-translations*
  `(:output-translations
    ;; Some implementations have precompiled ASDF systems,
    ;; so we must disable translations for implementation paths.
    #+sbcl (,(getenv "SBCL_HOME") ())
    #+ecl (,(translate-logical-pathname "SYS:**;*.*") ()) ; only needed if LPNs are resolved manually.
    #+clozure (,(wilden (ccl::ccl-directory)) ()) ; not needed: no precompiled ASDF system
    ;; All-import, here is where we want user stuff to be:
    :inherit-configuration
    ;; If we want to enable the user cache by default, here would be the place:
    :enable-user-cache))

(defun implementation-output-translations ()
  *implementation-output-translations*)

(defparameter *output-translations-file* #p"common-lisp/asdf-output-translations.conf")
(defparameter *output-translations-directory* #p"common-lisp/asdf-output-translations.conf.d/")

(defun user-output-translations-pathname ()
  (merge-pathnames* *output-translations-file* (user-configuration-directory)))
(defun system-output-translations-pathname ()
  (merge-pathnames* *output-translations-file* (system-configuration-directory)))
(defun user-output-translations-directory-pathname ()
  (merge-pathnames* *output-translations-directory* (user-configuration-directory)))
(defun system-output-translations-directory-pathname ()
  (merge-pathnames* *output-translations-directory* (system-configuration-directory)))
(defun environment-output-translations ()
  (getenv "ASDF_OUTPUT_TRANSLATIONS"))

(defgeneric process-output-translations (spec &key inherit collect))
(defmethod process-output-translations ((x symbol) &key
                                        (inherit *default-output-translations*)
                                        collect)
  (process-output-translations (funcall x) :inherit inherit :collect collect))
(defmethod process-output-translations ((pathname pathname) &key
                                        (inherit *default-output-translations*)
                                        collect)
  (cond
    ((directory-pathname-p pathname)
     (process-output-translations (validate-output-translations-directory pathname)
                                  :inherit inherit :collect collect))
    ((probe-file pathname)
     (process-output-translations (validate-output-translations-file pathname)
                                  :inherit inherit :collect collect))
    (t
     (inherit-output-translations inherit :collect collect))))
(defmethod process-output-translations ((string string) &key
                                        (inherit *default-output-translations*)
                                        collect)
  (process-output-translations (parse-output-translations-string string)
                               :inherit inherit :collect collect))
(defmethod process-output-translations ((x null) &key
                                    (inherit *default-output-translations*)
                                    collect)
  (declare (ignorable x))
  (inherit-output-translations inherit :collect collect))
(defmethod process-output-translations ((form cons) &key
                                        (inherit *default-output-translations*)
                                        collect)
  (dolist (directive (cdr (validate-output-translations-form form)))
    (process-output-translations-directive directive :inherit inherit :collect collect)))

(defun inherit-output-translations (inherit &key collect)
  (when inherit
    (process-output-translations (first inherit) :collect collect :inherit (rest inherit))))

(defun process-output-translations-directive (directive &key inherit collect)
  (if (atom directive)
      (ecase directive
        ((:enable-user-cache)
         (process-output-translations-directive '(:root :user-cache) :collect collect))
        ((:disable-cache)
         (process-output-translations-directive '(:root :root) :collect collect))
        ((:inherit-configuration)
         (inherit-output-translations inherit :collect collect))
        ((:ignore-inherited-configuration)
         nil))
      (let ((src (first directive))
            (dst (second directive)))
        (if (eq src :include)
            (when dst
              (process-output-translations (pathname dst) :inherit nil :collect collect))
            (let* ((trusrc (truenamize (resolve-location src t)))
                   (trudst (if dst (resolve-location dst t) trusrc)))
              (funcall collect (list trusrc trudst)))))))

(defun compute-output-translations
    (&optional (translations *default-output-translations*))
  "read the configuration, return it"
  (while-collecting (c)
    (inherit-output-translations translations :collect #'c)))

(defun initialize-output-translations
    (&optional (translations *default-output-translations*))
  "read the configuration, initialize the internal configuration variable,
return the configuration"
  (setf (output-translations) (compute-output-translations translations)))

;; checks an initial variable to see whether the state is initialized
;; or cleared. In the former case, return current configuration; in
;; the latter, initialize.  ASDF will call this function at the start
;; of (asdf:find-system).
(defun ensure-output-translations ()
  (if (output-translations-initialized-p)
      (output-translations)
      (initialize-output-translations)))

(defun apply-output-translations (path)
  (etypecase path
    (logical-pathname
     path)
    ((or pathname string)
     (ensure-output-translations)
     (setf path (truenamize path))
     (loop :for (source destination) :in (car *output-translations*)
       :when (pathname-match-p path source)
       :return (translate-pathname path source destination)
       :finally (return path)))))

(defmethod output-files :around ((op operation) (c component))
  "Method to rewrite output files to fasl-root"
  (mapcar #'apply-output-translations (call-next-method)))

(defun compile-file-pathname* (input-file &rest keys)
  (apply-output-translations
   (apply #'compile-file-pathname
          (truenamize (make-pathname :type "lisp" :defaults input-file))
          keys)))

;;;; -----------------------------------------------------------------
;;;; Windows shortcut support.  Based on:
;;;;
;;;; Jesse Hager: The Windows Shortcut File Format.
;;;; http://www.wotsit.org/list.asp?fc=13

(defparameter *link-initial-dword* 76)
(defparameter *link-guid* #(1 20 2 0 0 0 0 0 192 0 0 0 0 0 0 70))

(defun read-null-terminated-string (s)
  (with-output-to-string (out)
    (loop :for code = (read-byte s)
      :until (zerop code)
      :do (write-char (code-char code) out))))

(defun read-little-endian (s &optional (bytes 4))
  (loop
    :for i :from 0 :below bytes
    :sum (ash (read-byte s) (* 8 i))))

(defun parse-file-location-info (s)
  (let ((start (file-position s))
        (total-length (read-little-endian s))
        (end-of-header (read-little-endian s))
        (fli-flags (read-little-endian s))
        (local-volume-offset (read-little-endian s))
        (local-offset (read-little-endian s))
        (network-volume-offset (read-little-endian s))
        (remaining-offset (read-little-endian s)))
    (declare (ignore total-length end-of-header local-volume-offset))
    (unless (zerop fli-flags)
      (cond
        ((logbitp 0 fli-flags)
          (file-position s (+ start local-offset)))
        ((logbitp 1 fli-flags)
          (file-position s (+ start
                              network-volume-offset
                              #x14))))
      (concatenate 'string
        (read-null-terminated-string s)
        (progn
          (file-position s (+ start remaining-offset))
          (read-null-terminated-string s))))))

(defun parse-windows-shortcut (pathname)
  (with-open-file (s pathname :element-type '(unsigned-byte 8))
    (handler-case
        (when (and (= (read-little-endian s) *link-initial-dword*)
                   (let ((header (make-array (length *link-guid*))))
                     (read-sequence header s)
                     (equalp header *link-guid*)))
          (let ((flags (read-little-endian s)))
            (file-position s 76)        ;skip rest of header
            (when (logbitp 0 flags)
              ;; skip shell item id list
              (let ((length (read-little-endian s 2)))
                (file-position s (+ length (file-position s)))))
            (cond
              ((logbitp 1 flags)
                (parse-file-location-info s))
              (t
                (when (logbitp 2 flags)
                  ;; skip description string
                  (let ((length (read-little-endian s 2)))
                    (file-position s (+ length (file-position s)))))
                (when (logbitp 3 flags)
                  ;; finally, our pathname
                  (let* ((length (read-little-endian s 2))
                         (buffer (make-array length)))
                    (read-sequence buffer s)
                    (map 'string #'code-char buffer)))))))
      (end-of-file ()
        nil))))

;;;; -----------------------------------------------------------------
;;;; Source Registry Configuration, by Francois-Rene Rideau
;;;; See README.source-registry and https://bugs.launchpad.net/asdf/+bug/485918

;; Using ack 1.2 exclusions
(defvar *default-exclusions*
  '(".bzr" ".cdv" "~.dep" "~.dot" "~.nib" "~.plst"
    ".git" ".hg" ".pc" ".svn" "CVS" "RCS" "SCCS" "_darcs"
    "_sgbak" "autom4te.cache" "cover_db" "_build"))

(defvar *source-registry* ()
  "Either NIL (for uninitialized), or a list of one element,
said element itself being a list of directory pathnames where to look for .asd files")

(defun source-registry ()
  (car *source-registry*))

(defun (setf source-registry) (x)
  (setf *source-registry* (list x)))

(defun source-registry-initialized-p ()
  (and *source-registry* t))

(defun clear-source-registry ()
  "Undoes any initialization of the source registry.
You might want to call that before you dump an image that would be resumed
with a different configuration, so the configuration would be re-read then."
  (setf *source-registry* '())
  (values))

(defun sysdef-source-registry-search (system)
  (ensure-source-registry)
  (let ((name (coerce-name system)))
    (block nil
      (dolist (dir (source-registry))
        (let ((defaults (eval dir)))
          (when defaults
            (cond ((directory-pathname-p defaults)
                   (let ((file (and defaults
                                    (make-pathname
                                     :defaults defaults :version :newest
                                     :name name :type "asd" :case :local)))
                         #+(and (or win32 windows) (not :clisp))
                         (shortcut (make-pathname
                                    :defaults defaults :version :newest
                                    :name name :type "asd.lnk" :case :local)))
                     (when (and file (probe-file file))
                       (return file))
                     #+(and (or win32 windows) (not :clisp))
                     (when (probe-file shortcut)
                       (let ((target (parse-windows-shortcut shortcut)))
                         (when target
                           (return (pathname target))))))))))))))

(defun validate-source-registry-directive (directive)
  (unless
      (or (member directive '(:default-registry (:default-registry)) :test 'equal)
          (destructuring-bind (kw &rest rest) directive
            (case kw
              ((:include :directory :tree)
               (and (length=n-p rest 1)
                    (typep (car rest) '(or pathname string null))))
              ((:exclude)
               (every #'stringp rest))
              (null rest))))
    (error "Invalid directive ~S~%" directive))
  directive)

(defun validate-source-registry-form (form)
  (validate-configuration-form
   form :source-registry 'validate-source-registry-directive "a source registry"))

(defun validate-source-registry-file (file)
  (validate-configuration-file
   file 'validate-source-registry-form "a source registry"))

(defun validate-source-registry-directory (directory)
  (validate-configuration-directory
   directory :source-registry 'validate-source-registry-directive))

(defun parse-source-registry-string (string)
  (cond
    ((or (null string) (equal string ""))
     '(:source-registry :inherit-configuration))
    ((not (stringp string))
     (error "environment string isn't: ~S" string))
    ((eql (char string 0) "\"(")
     (validate-source-registry-form (read-from-string string)))
    (t
     (loop
      :with inherit = nil
      :with directives = ()
      :with start = 0
      :with end = (length string)
      :for i = (or (position #\: string :start start) end) :do
      (let ((s (subseq string start i)))
        (cond
         ((equal "" s) ; empty element: inherit
          (when inherit
            (error "only one inherited configuration allowed: ~S" string))
          (setf inherit t)
          (push ':inherit-configuration directives))
         ((ends-with s "//")
          (push `(:tree ,(subseq s 0 (1- (length s)))) directives))
         (t
          (push `(:directory ,s) directives)))
         (setf start (1+ i))
         (when (>= start end)
           (unless inherit
             (push '(:ignore-inherited-configuration) directives))
           (return `(:source-registry ,@(nreverse directives)))))))))

(defun register-asd-directory (directory &key recurse exclude collect)
  (if (not recurse)
      (funcall collect (ensure-directory-pathname directory))
      (let* ((files (ignore-errors
                      (directory (merge-pathnames* *wild-asd* directory)
                                 #+sbcl #+sbcl :resolve-symlinks nil
                                 #+clisp #+clisp :circle t)))
             (dirs (remove-duplicates (mapcar #'pathname-directory-pathname files)
                                      :test #'equal)))
        (loop
          :for dir :in dirs
          :unless (loop :for x :in exclude
                    :thereis (find x (pathname-directory dir) :test #'equal))
          :do (funcall collect dir)))))

(defparameter *default-source-registries*
  '(environment-source-registry
    user-source-registry
    user-source-registry-directory
    system-source-registry
    system-source-registry-directory))

(defparameter *source-registry-file* #p"common-lisp/source-registry.conf")
(defparameter *source-registry-directory* #p"common-lisp/source-registry.conf.d/")

(defun wrapping-source-registry ()
  `(:source-registry
    #+sbcl (:tree ,(getenv "SBCL_HOME"))
   :inherit-configuration))
(defun default-source-registry ()
  `(:source-registry
    #+sbcl (:directory ,(merge-pathnames* ".sbcl/systems/" (user-homedir-pathname)))
    (:directory ,(truenamize (directory-namestring *default-pathname-defaults*)))
    (:directory ,(merge-pathnames* ".local/share/common-lisp/systems/" (user-homedir-pathname)))
    (:tree ,(merge-pathnames* ".local/share/common-lisp/source/" (user-homedir-pathname)))
    (:directory "/usr/local/share/common-lisp/systems/")
    (:tree "/usr/local/share/common-lisp/source/")
    (:directory "/usr/local/share/common-lisp/systems/")
    (:tree "/usr/local/share/common-lisp/source/")
    (:directory "/usr/share/common-lisp/systems/")
    (:tree "/usr/share/common-lisp/source/")
    :inherit-configuration))
(defun user-source-registry ()
  (merge-pathnames* *source-registry-file* (user-configuration-directory)))
(defun system-source-registry ()
  (merge-pathnames* *source-registry-file* (system-configuration-directory)))
(defun user-source-registry-directory ()
  (merge-pathnames* *source-registry-directory* (user-configuration-directory)))
(defun system-source-registry-directory ()
  (merge-pathnames* *source-registry-directory* (system-configuration-directory)))
(defun environment-source-registry ()
  (getenv "CL_SOURCE_REGISTRY"))

(defgeneric process-source-registry (spec &key inherit register))
(defmethod process-source-registry ((x symbol) &key inherit register)
  (process-source-registry (funcall x) :inherit inherit :register register))
(defmethod process-source-registry ((pathname pathname) &key inherit register)
  (cond
    ((directory-pathname-p pathname)
     (process-source-registry (validate-source-registry-directory pathname)
                              :inherit inherit :register register))
    ((probe-file pathname)
     (process-source-registry (validate-source-registry-file pathname)
                              :inherit inherit :register register))
    (t
     (inherit-source-registry inherit :register register))))
(defmethod process-source-registry ((string string) &key inherit register)
  (process-source-registry (parse-source-registry-string string)
                           :inherit inherit :register register))
(defmethod process-source-registry ((x null) &key inherit register)
  (declare (ignorable x))
  (inherit-source-registry inherit :register register))
(defmethod process-source-registry ((form cons) &key inherit register)
  (let ((*default-exclusions* *default-exclusions*))
    (dolist (directive (cdr (validate-source-registry-form form)))
      (process-source-registry-directive directive :inherit inherit :register register))))

(defun inherit-source-registry (inherit &key register)
  (when inherit
    (process-source-registry (first inherit) :register register :inherit (rest inherit))))

(defun process-source-registry-directive (directive &key inherit register)
  (destructuring-bind (kw &rest rest) (if (consp directive) directive (list directive))
    (ecase kw
      ((:include)
       (destructuring-bind (pathname) rest
         (process-source-registry (pathname pathname) :inherit nil :register register)))
      ((:directory)
       (destructuring-bind (pathname) rest
         (when pathname
           (funcall register (pathname pathname)))))
      ((:tree)
       (destructuring-bind (pathname) rest
         (when pathname
           (funcall register (pathname pathname) :recurse t :exclude *default-exclusions*))))
      ((:exclude)
       (setf *default-exclusions* rest))
      ((:default-registry)
       (inherit-source-registry '(default-source-registry) :register register))
      ((:inherit-configuration)
       (inherit-source-registry inherit :register register))
      ((:ignore-inherited-configuration)
       nil))))

(defun flatten-source-registry (registries)
  (while-collecting (collect)
    (inherit-source-registry
     registries
     :register (lambda (directory &key recurse exclude)
                 (collect (list directory :recurse recurse :exclude exclude))))))

;; Will read the configuration and initialize all internal variables,
;; and return the new configuration.
(defun compute-source-registry (&optional parameter)
  (let* ((flattened
          (flatten-source-registry
           `(wrapping-source-registry
             ,parameter
             ,@*default-source-registries*
             default-source-registry)))
         (simplified
          (remove-duplicates flattened :test 'equal :from-end nil))
         (processed
          (while-collecting (collect)
            (dolist (entry simplified)
              (destructuring-bind (directory &key recurse exclude) entry
                (register-asd-directory
                 directory
                 :recurse recurse :exclude exclude :collect #'collect))))))
    processed))

(defun initialize-source-registry (&optional parameter)
  (setf (source-registry) (compute-source-registry parameter)))

;; checks an initial variable to see whether the state is initialized
;; or cleared. In the former case, return current configuration; in
;; the latter, initialize.  ASDF will call this function at the start
;; of (asdf:find-system).
(defun ensure-source-registry ()
  (if (source-registry-initialized-p)
      (source-registry)
      (initialize-source-registry)))

;;;; -----------------------------------------------------------------
;;;; SBCL hook into REQUIRE
;;;;
#+sbcl
(progn
  (defun module-provide-asdf (name)
    (handler-bind ((style-warning #'muffle-warning))
      (let* ((*verbose-out* (make-broadcast-stream))
             (system (asdf:find-system name nil)))
        (when system
          (asdf:operate 'asdf:load-op name)
          t))))
  (pushnew 'module-provide-asdf sb-ext:*module-provider-functions*))

;;;; -------------------------------------------------------------------------
;;;; Cleanups after hot-upgrade.
;;;; Things to do in case we're upgrading from a previous version of ASDF.
;;;; See https://bugs.launchpad.net/asdf/+bug/485687
;;;;
;;;; TODO: debug why it's not enough to upgrade from ECL <= 9.11.1
(eval-when (:compile-toplevel :load-toplevel :execute)
  #+ecl ;; Support upgrade from before ECL went to 1.369
  (when (fboundp 'compile-op-system-p)
    (defmethod compile-op-system-p ((op compile-op))
      (getf :system-p (compile-op-flags op)))
    (defmethod initialize-instance :after ((op compile-op)
                                           &rest initargs
                                           &key system-p &allow-other-keys)
      (declare (ignorable initargs))
      (when system-p (appendf (compile-op-flags op) (list :system-p system-p))))))

;;;; -----------------------------------------------------------------
;;;; Done!
(when *load-verbose*
  (asdf-message ";; ASDF, version ~a" (asdf-version)))

#+allegro
(eval-when (:compile-toplevel :execute)
  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
    (setf excl:*warn-on-nested-reader-conditionals* *acl-warn-save*)))

(pushnew :asdf *features*)
;; this is a release candidate for ASDF 2.0
(pushnew :asdf2 *features*)

(provide :asdf)

;;; Local Variables:
;;; mode: lisp
;;; End: