X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-package.lisp;h=4b19fa7dbb176ace7f462046298366fd9fb277a7;hb=506af5859d361f5e9744ca9a177bf47746333df3;hp=a8a8ea7254d111cb4dda18c4344e62cd87741fac;hpb=82653abf5573c22c691e2243b70647ecdaa6aea8;p=sbcl.git diff --git a/src/code/target-package.lisp b/src/code/target-package.lisp index a8a8ea7..4b19fa7 100644 --- a/src/code/target-package.lisp +++ b/src/code/target-package.lisp @@ -8,6 +8,9 @@ ;;;; symbol. A name conflict is said to occur when there would be more ;;;; than one candidate symbol. Any time a name conflict is about to ;;;; occur, a correctable error is signaled. +;;;; +;;;; FIXME: The code contains a lot of type declarations. Are they +;;;; all really necessary? ;;;; This software is part of the SBCL system. See the README file for ;;;; more information. @@ -25,74 +28,460 @@ (!cold-init-forms (/show0 "entering !PACKAGE-COLD-INIT")) +;;;; Thread safety +;;;; +;;;; ...this could still use work, but the basic idea is: +;;;; +;;;; *PACKAGE-GRAPH-LOCK* is held via WITH-PACKAGE-GRAPH while working on +;;;; package graph, including package -> package links, and interning and +;;;; uninterning symbols. +;;;; +;;;; Hash-table lock on *PACKAGE-NAMES* is held via WITH-PACKAGE-NAMES while +;;;; frobbing name -> package associations. +;;;; +;;;; There should be no deadlocks due to ordering issues between these two, as +;;;; the latter is only held over operations guaranteed to terminate in finite +;;;; time. +;;;; +;;;; Errors may be signalled while holding on to the *PACKAGE-GRAPH-LOCK*, +;;;; which can still lead to pretty damned inconvenient situations -- but +;;;; since FIND-PACKAGE, FIND-SYMBOL from other threads isn't blocked by this, +;;;; the situation isn't *quite* hopeless. +;;;; +;;;; A better long-term solution seems to be in splitting the granularity of +;;;; the *PACKAGE-GRAPH-LOCK* down: for interning a per-package lock should be +;;;; sufficient, though interaction between parallel intern and use-package +;;;; needs to be considered with some care. + +(defvar *package-graph-lock*) +(!cold-init-forms + (setf *package-graph-lock* (sb!thread:make-mutex :name "Package Graph Lock"))) + +(defun call-with-package-graph (function) + (declare (function function)) + ;; FIXME: Since name conflicts can be signalled while holding the + ;; mutex, user code can be run leading to lock ordering problems. + (sb!thread:with-recursive-lock (*package-graph-lock*) + (funcall function))) + +;;; a map from package names to packages +(defvar *package-names*) +(declaim (type hash-table *package-names*)) +(!cold-init-forms + (setf *package-names* (make-hash-table :test 'equal :synchronized t))) + +(defmacro with-package-names ((names &key) &body body) + `(let ((,names *package-names*)) + (with-locked-system-table (,names) + ,@body))) + ;;;; PACKAGE-HASHTABLE stuff (def!method print-object ((table package-hashtable) stream) (declare (type stream stream)) (print-unreadable-object (table stream :type t) (format stream - ":SIZE ~S :FREE ~S :DELETED ~S" - (package-hashtable-size table) - (package-hashtable-free table) - (package-hashtable-deleted table)))) + ":SIZE ~S :FREE ~S :DELETED ~S" + (package-hashtable-size table) + (package-hashtable-free table) + (package-hashtable-deleted table)))) -;;; the maximum density we allow in a package hashtable -(defconstant package-rehash-threshold 0.75) +;;; the maximum load factor we allow in a package hashtable +(defconstant +package-rehash-threshold+ 0.75) + +;;; the load factor desired for a package hashtable when writing a +;;; core image +(defconstant +package-hashtable-image-load-factor+ 0.5) ;;; Make a package hashtable having a prime number of entries at least -;;; as great as (/ SIZE PACKAGE-REHASH-THRESHOLD). If RES is supplied, +;;; as great as (/ SIZE +PACKAGE-REHASH-THRESHOLD+). If RES is supplied, ;;; then it is destructively modified to produce the result. This is ;;; useful when changing the size, since there are many pointers to ;;; the hashtable. +;;; Actually, the smallest table built here has three entries. This +;;; is necessary because the double hashing step size is calculated +;;; using a division by the table size minus two. (defun make-or-remake-package-hashtable (size - &optional - (res (%make-package-hashtable))) - (do ((n (logior (truncate size package-rehash-threshold) 1) - (+ n 2))) - ((positive-primep n) - (setf (package-hashtable-table res) - (make-array n)) - (setf (package-hashtable-hash res) - (make-array n - :element-type '(unsigned-byte 8) - :initial-element 0)) - (let ((size (truncate (* n package-rehash-threshold)))) - (setf (package-hashtable-size res) size) - (setf (package-hashtable-free res) size)) - (setf (package-hashtable-deleted res) 0) - res) - (declare (type fixnum n)))) + &optional + res) + (flet ((actual-package-hashtable-size (size) + (loop for n of-type fixnum + from (logior (ceiling size +package-rehash-threshold+) 1) + by 2 + when (positive-primep n) return n))) + (let* ((n (actual-package-hashtable-size size)) + (size (truncate (* n +package-rehash-threshold+))) + (table (make-array n)) + (hash (make-array n + :element-type '(unsigned-byte 8) + :initial-element 0))) + (if res + (setf (package-hashtable-table res) table + (package-hashtable-hash res) hash + (package-hashtable-size res) size + (package-hashtable-free res) size + (package-hashtable-deleted res) 0) + (setf res (%make-package-hashtable table hash size))) + res))) + +;;; Destructively resize TABLE to have room for at least SIZE entries +;;; and rehash its existing entries. +(defun resize-package-hashtable (table size) + (let* ((vec (package-hashtable-table table)) + (hash (package-hashtable-hash table)) + (len (length vec))) + (make-or-remake-package-hashtable size table) + (dotimes (i len) + (when (> (aref hash i) 1) + (add-symbol table (svref vec i)))))) + +;;;; package locking operations, built conditionally on :sb-package-locks + +#!+sb-package-locks +(progn +(defun package-locked-p (package) + #!+sb-doc + "Returns T when PACKAGE is locked, NIL otherwise. Signals an error +if PACKAGE doesn't designate a valid package." + (package-lock (find-undeleted-package-or-lose package))) + +(defun lock-package (package) + #!+sb-doc + "Locks PACKAGE and returns T. Has no effect if PACKAGE was already +locked. Signals an error if PACKAGE is not a valid package designator" + (setf (package-lock (find-undeleted-package-or-lose package)) t)) + +(defun unlock-package (package) + #!+sb-doc + "Unlocks PACKAGE and returns T. Has no effect if PACKAGE was already +unlocked. Signals an error if PACKAGE is not a valid package designator." + (setf (package-lock (find-undeleted-package-or-lose package)) nil) + t) + +(defun package-implemented-by-list (package) + #!+sb-doc + "Returns a list containing the implementation packages of +PACKAGE. Signals an error if PACKAGE is not a valid package designator." + (package-%implementation-packages (find-undeleted-package-or-lose package))) + +(defun package-implements-list (package) + #!+sb-doc + "Returns the packages that PACKAGE is an implementation package +of. Signals an error if PACKAGE is not a valid package designator." + (let ((package (find-undeleted-package-or-lose package))) + (loop for x in (list-all-packages) + when (member package (package-%implementation-packages x)) + collect x))) + +(defun add-implementation-package (packages-to-add + &optional (package *package*)) + #!+sb-doc + "Adds PACKAGES-TO-ADD as implementation packages of PACKAGE. Signals +an error if PACKAGE or any of the PACKAGES-TO-ADD is not a valid +package designator." + (let ((package (find-undeleted-package-or-lose package)) + (packages-to-add (package-listify packages-to-add))) + (setf (package-%implementation-packages package) + (union (package-%implementation-packages package) + (mapcar #'find-undeleted-package-or-lose packages-to-add))))) + +(defun remove-implementation-package (packages-to-remove + &optional (package *package*)) + #!+sb-doc + "Removes PACKAGES-TO-REMOVE from the implementation packages of +PACKAGE. Signals an error if PACKAGE or any of the PACKAGES-TO-REMOVE +is not a valid package designator." + (let ((package (find-undeleted-package-or-lose package)) + (packages-to-remove (package-listify packages-to-remove))) + (setf (package-%implementation-packages package) + (nset-difference + (package-%implementation-packages package) + (mapcar #'find-undeleted-package-or-lose packages-to-remove))))) + +(defmacro with-unlocked-packages ((&rest packages) &body forms) + #!+sb-doc + "Unlocks PACKAGES for the dynamic scope of the body. Signals an +error if any of PACKAGES is not a valid package designator." + (with-unique-names (unlocked-packages) + `(let (,unlocked-packages) + (unwind-protect + (progn + (dolist (p ',packages) + (when (package-locked-p p) + (push p ,unlocked-packages) + (unlock-package p))) + ,@forms) + (dolist (p ,unlocked-packages) + (when (find-package p) + (lock-package p))))))) + +(defun package-lock-violation (package &key (symbol nil symbol-p) + format-control format-arguments) + (let* ((restart :continue) + (cl-violation-p (eq package *cl-package*)) + (error-arguments + (append (list (if symbol-p + 'symbol-package-locked-error + 'package-locked-error) + :package package + :format-control format-control + :format-arguments format-arguments) + (when symbol-p (list :symbol symbol)) + (list :references + (append '((:sbcl :node "Package Locks")) + (when cl-violation-p + '((:ansi-cl :section (11 1 2 1 2))))))))) + (restart-case + (apply #'cerror "Ignore the package lock." error-arguments) + (:ignore-all () + :report "Ignore all package locks in the context of this operation." + (setf restart :ignore-all)) + (:unlock-package () + :report "Unlock the package." + (setf restart :unlock-package))) + (ecase restart + (:continue + (pushnew package *ignored-package-locks*)) + (:ignore-all + (setf *ignored-package-locks* t)) + (:unlock-package + (unlock-package package))))) + +(defun package-lock-violation-p (package &optional (symbol nil symbolp)) + ;; KLUDGE: (package-lock package) needs to be before + ;; comparison to *package*, since during cold init this gets + ;; called before *package* is bound -- but no package should + ;; be locked at that point. + (and package + (package-lock package) + ;; In package or implementation package + (not (or (eq package *package*) + (member *package* (package-%implementation-packages package)))) + ;; Runtime disabling + (not (eq t *ignored-package-locks*)) + (or (eq :invalid *ignored-package-locks*) + (not (member package *ignored-package-locks*))) + ;; declarations for symbols + (not (and symbolp (member symbol (disabled-package-locks)))))) + +(defun disabled-package-locks () + (if (boundp 'sb!c::*lexenv*) + (sb!c::lexenv-disabled-package-locks sb!c::*lexenv*) + sb!c::*disabled-package-locks*)) + +) ; progn + +;;;; more package-locking these are NOPs unless :sb-package-locks is +;;;; in target features. Cross-compiler NOPs for these are in cross-misc. + +;;; The right way to establish a package lock context is +;;; WITH-SINGLE-PACKAGE-LOCKED-ERROR, defined in early-package.lisp +;;; +;;; Must be used inside the dynamic contour established by +;;; WITH-SINGLE-PACKAGE-LOCKED-ERROR +(defun assert-package-unlocked (package &optional format-control + &rest format-arguments) + #!-sb-package-locks + (declare (ignore format-control format-arguments)) + #!+sb-package-locks + (when (package-lock-violation-p package) + (package-lock-violation package + :format-control format-control + :format-arguments format-arguments)) + package) + +;;; Must be used inside the dynamic contour established by +;;; WITH-SINGLE-PACKAGE-LOCKED-ERROR. +;;; +;;; FIXME: Maybe we should establish such contours for he toplevel +;;; and others, so that %set-fdefinition and others could just use +;;; this. +(defun assert-symbol-home-package-unlocked (name format) + #!-sb-package-locks + (declare (ignore format)) + #!+sb-package-locks + (let* ((symbol (etypecase name + (symbol name) + (list (if (and (consp (cdr name)) + (eq 'setf (first name))) + (second name) + ;; Skip lists of length 1, single conses and + ;; (class-predicate foo), etc. + ;; FIXME: MOP and package-lock + ;; interaction needs to be thought about. + (return-from + assert-symbol-home-package-unlocked + name))))) + (package (symbol-package symbol))) + (when (package-lock-violation-p package symbol) + (package-lock-violation package + :symbol symbol + :format-control format + :format-arguments (list name)))) + name) + ;;;; miscellaneous PACKAGE operations (def!method print-object ((package package) stream) (let ((name (package-%name package))) (if name - (print-unreadable-object (package stream :type t) - (prin1 name stream)) - (print-unreadable-object (package stream :type t :identity t) - (write-string "(deleted)" stream))))) + (print-unreadable-object (package stream :type t) + (prin1 name stream)) + (print-unreadable-object (package stream :type t :identity t) + (write-string "(deleted)" stream))))) ;;; ANSI says (in the definition of DELETE-PACKAGE) that these, and ;;; most other operations, are unspecified for deleted packages. We ;;; just do the easy thing and signal errors in that case. (macrolet ((def (ext real) - `(defun ,ext (x) (,real (find-undeleted-package-or-lose x))))) + `(defun ,ext (package-designator) + (,real (find-undeleted-package-or-lose package-designator))))) (def package-nicknames package-%nicknames) (def package-use-list package-%use-list) (def package-used-by-list package-%used-by-list) (def package-shadowing-symbols package-%shadowing-symbols)) +(defun package-local-nicknames (package-designator) + "Returns an alist of \(local-nickname . actual-package) describing the +nicknames local to the designated package. + +When in the designated package, calls to FIND-PACKAGE with the any of the +local-nicknames will return the corresponding actual-package instead. This +also affects all implied calls to FIND-PACKAGE, including those performed by +the reader. + +When printing a package prefix for a symbol with a package local nickname, the +local nickname is used instead of the real name in order to preserve +print-read consistency. + +See also: ADD-PACKAGE-LOCAL-NICKNAME, PACKAGE-LOCALLY-NICKNAMED-BY-LIST, +REMOVE-PACKAGE-LOCAL-NICKNAME, and the DEFPACKAGE option :LOCAL-NICKNAMES. + +Experimental: interface subject to change." + (copy-tree + (package-%local-nicknames + (find-undeleted-package-or-lose package-designator)))) + +(defun package-locally-nicknamed-by-list (package-designator) + "Returns a list of packages which have a local nickname for the designated +package. + +See also: ADD-PACKAGE-LOCAL-NICKNAME, PACKAGE-LOCAL-NICKNAMES, +REMOVE-PACKAGE-LOCAL-NICKNAME, and the DEFPACKAGE option :LOCAL-NICKNAMES. + +Experimental: interface subject to change." + (copy-list + (package-%locally-nicknamed-by + (find-undeleted-package-or-lose package-designator)))) + +(defun add-package-local-nickname (local-nickname actual-package + &optional (package-designator (sane-package))) + "Adds LOCAL-NICKNAME for ACTUAL-PACKAGE in the designated package, defaulting +to current package. LOCAL-NICKNAME must be a string designator, and +ACTUAL-PACKAGE must be a package designator. + +Returns the designated package. + +Signals a continuable error if LOCAL-NICKNAME is already a package local +nickname for a different package, or if LOCAL-NICKNAME is one of \"CL\", +\"COMMON-LISP\", or, \"KEYWORD\", or if LOCAL-NICKNAME is a global name or +nickname for the package to which the nickname would be added. + +When in the designated package, calls to FIND-PACKAGE with the LOCAL-NICKNAME +will return the package the designated ACTUAL-PACKAGE instead. This also +affects all implied calls to FIND-PACKAGE, including those performed by the +reader. + +When printing a package prefix for a symbol with a package local nickname, +local nickname is used instead of the real name in order to preserve +print-read consistency. + +See also: PACKAGE-LOCAL-NICKNAMES, PACKAGE-LOCALLY-NICKNAMED-BY-LIST, +REMOVE-PACKAGE-LOCAL-NICKNAME, and the DEFPACKAGE option :LOCAL-NICKNAMES. + +Experimental: interface subject to change." + (let* ((nick (string local-nickname)) + (actual (find-package-using-package actual-package nil)) + (package (find-undeleted-package-or-lose package-designator)) + (existing (package-%local-nicknames package)) + (cell (assoc nick existing :test #'string=))) + (unless (package-name actual) + (error "Cannot add ~A as local nickname for a deleted package: ~S" + nick actual)) + (with-single-package-locked-error + (:package package "adding ~A as a local nickname for ~A" + nick actual)) + (when (member nick '("CL" "COMMON-LISP" "KEYWORD") :test #'string=) + (cerror "Continue, use it as local nickname anyways." + "Attempt to use ~A as a package local nickname (for ~A)." + nick (package-name actual))) + (when (string= nick (package-name package)) + (cerror "Continue, use it as a local nickname anyways." + "Attempt to use ~A as a package local nickname (for ~A) in ~ + package named globally ~A." + nick (package-name actual) nick)) + (when (member nick (package-nicknames package) :test #'string=) + (cerror "Continue, use it as a local nickname anyways." + "Attempt to use ~A as a package local nickname (for ~A) in ~ + package nicknamed globally ~A." + nick (package-name actual) nick)) + (when (and cell (neq actual (cdr cell))) + (restart-case + (error "~@" + nick actual package (cdr cell)) + (keep-old () + :report (lambda (s) + (format s "Keep ~A as local nicname for ~A." + nick (cdr cell)))) + (change-nick () + :report (lambda (s) + (format s "Use ~A as local nickname for ~A instead." + nick actual)) + (let ((old (cdr cell))) + (with-package-graph () + (setf (package-%locally-nicknamed-by old) + (delete package (package-%locally-nicknamed-by old))) + (push package (package-%locally-nicknamed-by actual)) + (setf (cdr cell) actual))))) + (return-from add-package-local-nickname package)) + (unless cell + (with-package-graph () + (push (cons nick actual) (package-%local-nicknames package)) + (push package (package-%locally-nicknamed-by actual)))) + package)) + +(defun remove-package-local-nickname (old-nickname + &optional (package-designator (sane-package))) + "If the designated package had OLD-NICKNAME as a local nickname for +another package, it is removed. Returns true if the nickname existed and was +removed, and NIL otherwise. + +See also: ADD-PACKAGE-LOCAL-NICKNAME, PACKAGE-LOCAL-NICKNAMES, +PACKAGE-LOCALLY-NICKNAMED-BY-LIST, and the DEFPACKAGE option :LOCAL-NICKNAMES. + +Experimental: interface subject to change." + (let* ((nick (string old-nickname)) + (package (find-undeleted-package-or-lose package-designator)) + (existing (package-%local-nicknames package)) + (cell (assoc nick existing :test #'string=))) + (when cell + (with-single-package-locked-error + (:package package "removing local nickname ~A for ~A" + nick (cdr cell))) + (with-package-graph () + (let ((old (cdr cell))) + (setf (package-%local-nicknames package) (delete cell existing)) + (setf (package-%locally-nicknamed-by old) + (delete package (package-%locally-nicknamed-by old))))) + t))) + (defun %package-hashtable-symbol-count (table) (let ((size (the fixnum - (- (the fixnum (package-hashtable-size table)) - (the fixnum - (package-hashtable-deleted table)))))) - (declare (fixnum size)) + (- (package-hashtable-size table) + (package-hashtable-deleted table))))) (the fixnum - (- size - (the fixnum - (package-hashtable-free table)))))) + (- size (package-hashtable-free table))))) (defun package-internal-symbol-count (package) (%package-hashtable-symbol-count (package-internal-symbols package))) @@ -100,17 +489,11 @@ (defun package-external-symbol-count (package) (%package-hashtable-symbol-count (package-external-symbols package))) -(defvar *package* (error "*PACKAGE* should be initialized in cold load!") +(defvar *package* (error "*PACKAGE* should be initialized in cold load!") #!+sb-doc "the current package") ;;; FIXME: should be declared of type PACKAGE, with no NIL init form, ;;; after I get around to cleaning up DOCUMENTATION -;;; a map from package names to packages -(defvar *package-names*) -(declaim (type hash-table *package-names*)) -(!cold-init-forms - (setf *package-names* (make-hash-table :test 'equal))) - ;;; This magical variable is T during initialization so that ;;; USE-PACKAGE's of packages that don't yet exist quietly win. Such ;;; packages are thrown onto the list *DEFERRED-USE-PACKAGES* so that @@ -127,20 +510,65 @@ (!cold-init-forms (setf *!deferred-use-packages* nil)) -;;; FIXME: I rewrote this. Test it and the stuff that calls it. +(define-condition bootstrap-package-not-found (condition) + ((name :initarg :name :reader bootstrap-package-name))) +(defun debootstrap-package (&optional condition) + (invoke-restart + (find-restart-or-control-error 'debootstrap-package condition))) + (defun find-package (package-designator) + "If PACKAGE-DESIGNATOR is a package, it is returned. Otherwise PACKAGE-DESIGNATOR +must be a string designator, in which case the package it names is located and returned. + +As an SBCL extension, the current package may effect the way a package name is +resolved: if the current package has local nicknames specified, package names +matching those are resolved to the packages associated with them instead. + +Example: + + (defpackage :a) + (defpackage :example (:use :cl) (:local-nicknames (:x :a))) + (let ((*package* (find-package :example))) + (find-package :x)) => # + +See also: ADD-PACKAGE-LOCAL-NICKNAME, PACKAGE-LOCAL-NICKNAMES, +REMOVE-PACKAGE-LOCAL-NICKNAME, and the DEFPACKAGE option :LOCAL-NICKNAMES." + (find-package-using-package package-designator + (when (boundp '*package*) + *package*))) + +;;; This is undocumented and unexported for now, but the idea is that by +;;; making this a generic function then packages with custom package classes +;;; could hook into this to provide their own resolution. +(defun find-package-using-package (package-designator base) (flet ((find-package-from-string (string) - (declare (type string string)) - (values (gethash string *package-names*)))) - (declare (inline find-package-from-string)) + (declare (type string string)) + (let* ((nicknames (when base + (package-%local-nicknames base))) + (nicknamed (when nicknames + (cdr (assoc string nicknames :test #'string=)))) + (packageoid (or nicknamed (gethash string *package-names*)))) + (when (and (null packageoid) + (not *in-package-init*) ; KLUDGE + (let ((mismatch (mismatch "SB!" string))) + (and mismatch (= mismatch 3)))) + (restart-case + (signal 'bootstrap-package-not-found :name string) + (debootstrap-package () + (return-from find-package-using-package + (if (string= string "SB!XC") + (find-package "COMMON-LISP") + (find-package + (substitute #\- #\! string :count 1))))))) + packageoid))) (typecase package-designator (package package-designator) (symbol (find-package-from-string (symbol-name package-designator))) (string (find-package-from-string package-designator)) (character (find-package-from-string (string package-designator))) (t (error 'type-error - :datum package-designator - :expected-type '(or character package string symbol)))))) + :datum package-designator + :expected-type '(or character package string symbol)))))) ;;; Return a list of packages given a package designator or list of ;;; package designators, or die trying. @@ -151,7 +579,7 @@ ;;; Make a package name into a simple-string. (defun package-namify (n) - (stringify-name n "package")) + (stringify-package-designator n)) ;;; ANSI specifies (in the definition of DELETE-PACKAGE) that PACKAGE-NAME ;;; returns NIL (not an error) for a deleted package, so this is a special @@ -166,178 +594,199 @@ ;;; must be between 2 and 255. (defmacro entry-hash (length sxhash) `(the fixnum - (+ (the fixnum - (rem (the fixnum - (logxor ,length - ,sxhash - (the fixnum (ash ,sxhash -8)) - (the fixnum (ash ,sxhash -16)) - (the fixnum (ash ,sxhash -19)))) - 254)) - 2))) + (+ (the fixnum + (rem (the fixnum + (logxor ,length + ,sxhash + (the fixnum (ash ,sxhash -8)) + (the fixnum (ash ,sxhash -16)) + (the fixnum (ash ,sxhash -19)))) + 254)) + 2))) ;;; FIXME: should be wrapped in EVAL-WHEN (COMPILE EXECUTE) ;;; Add a symbol to a package hashtable. The symbol is assumed ;;; not to be present. (defun add-symbol (table symbol) + (when (zerop (package-hashtable-free table)) + ;; The hashtable is full. Resize it to be able to hold twice the + ;; amount of symbols than it currently contains. The actual new size + ;; can be smaller than twice the current size if the table contained + ;; deleted entries. + (resize-package-hashtable table + (* (- (package-hashtable-size table) + (package-hashtable-deleted table)) + 2))) (let* ((vec (package-hashtable-table table)) - (hash (package-hashtable-hash table)) - (len (length vec)) - (sxhash (%sxhash-simple-string (symbol-name symbol))) - (h2 (the fixnum (1+ (the fixnum (rem sxhash - (the fixnum (- len 2)))))))) - (declare (simple-vector vec) - (type (simple-array (unsigned-byte 8)) hash) - (fixnum len sxhash h2)) - (cond ((zerop (the fixnum (package-hashtable-free table))) - (make-or-remake-package-hashtable (* (package-hashtable-size table) - 2) - table) - (add-symbol table symbol) - (dotimes (i len) - (declare (fixnum i)) - (when (> (the fixnum (aref hash i)) 1) - (add-symbol table (svref vec i))))) - (t - (do ((i (rem sxhash len) (rem (+ i h2) len))) - ((< (the fixnum (aref hash i)) 2) - (if (zerop (the fixnum (aref hash i))) - (decf (the fixnum (package-hashtable-free table))) - (decf (the fixnum (package-hashtable-deleted table)))) - (setf (svref vec i) symbol) - (setf (aref hash i) - (entry-hash (length (the simple-string - (symbol-name symbol))) - sxhash))) - (declare (fixnum i))))))) - -;;; Find where the symbol named String is stored in Table. Index-Var -;;; is bound to the index, or NIL if it is not present. Symbol-Var -;;; is bound to the symbol. Length and Hash are the length and sxhash -;;; of String. Entry-Hash is the entry-hash of the string and length. + (hash (package-hashtable-hash table)) + (len (length vec)) + (sxhash (%sxhash-simple-string (symbol-name symbol))) + (h2 (1+ (rem sxhash (- len 2))))) + (declare (fixnum sxhash h2)) + (do ((i (rem sxhash len) (rem (+ i h2) len))) + ((< (the fixnum (aref hash i)) 2) + (if (zerop (the fixnum (aref hash i))) + (decf (package-hashtable-free table)) + (decf (package-hashtable-deleted table))) + (setf (svref vec i) symbol) + (setf (aref hash i) + (entry-hash (length (symbol-name symbol)) + sxhash))) + (declare (fixnum i))))) + +;;; Resize the package hashtables of all packages so that their load +;;; factor is +PACKAGE-HASHTABLE-IMAGE-LOAD-FACTOR+. Called from +;;; SAVE-LISP-AND-DIE to optimize space usage in the image. +(defun tune-hashtable-sizes-of-all-packages () + (flet ((tune-table-size (table) + (resize-package-hashtable + table + (round (* (/ +package-rehash-threshold+ + +package-hashtable-image-load-factor+) + (- (package-hashtable-size table) + (package-hashtable-free table) + (package-hashtable-deleted table))))))) + (dolist (package (list-all-packages)) + (tune-table-size (package-internal-symbols package)) + (tune-table-size (package-external-symbols package))))) + +;;; Find where the symbol named STRING is stored in TABLE. INDEX-VAR +;;; is bound to the index, or NIL if it is not present. SYMBOL-VAR +;;; is bound to the symbol. LENGTH and HASH are the length and sxhash +;;; of STRING. ENTRY-HASH is the entry-hash of the string and length. (defmacro with-symbol ((index-var symbol-var table string length sxhash - entry-hash) - &body forms) + entry-hash) + &body forms) (let ((vec (gensym)) (hash (gensym)) (len (gensym)) (h2 (gensym)) - (name (gensym)) (name-len (gensym)) (ehash (gensym))) + (name (gensym)) (name-len (gensym)) (ehash (gensym))) `(let* ((,vec (package-hashtable-table ,table)) - (,hash (package-hashtable-hash ,table)) - (,len (length ,vec)) - (,h2 (1+ (the index (rem (the index ,sxhash) - (the index (- ,len 2))))))) - (declare (type (simple-array (unsigned-byte 8) (*)) ,hash) - (simple-vector ,vec) - (type index ,len ,h2)) - (prog ((,index-var (rem (the index ,sxhash) ,len)) - ,symbol-var ,ehash) - (declare (type (or index null) ,index-var)) - LOOP - (setq ,ehash (aref ,hash ,index-var)) - (cond ((eql ,ehash ,entry-hash) - (setq ,symbol-var (svref ,vec ,index-var)) - (let* ((,name (symbol-name ,symbol-var)) - (,name-len (length ,name))) - (declare (simple-string ,name) - (type index ,name-len)) - (when (and (= ,name-len ,length) - (string= ,string ,name - :end1 ,length - :end2 ,name-len)) - (go DOIT)))) - ((zerop ,ehash) - (setq ,index-var nil) - (go DOIT))) - (setq ,index-var (+ ,index-var ,h2)) - (when (>= ,index-var ,len) - (setq ,index-var (- ,index-var ,len))) - (go LOOP) - DOIT - (return (progn ,@forms)))))) + (,hash (package-hashtable-hash ,table)) + (,len (length ,vec)) + (,h2 (1+ (the index (rem (the hash ,sxhash) + (the index (- ,len 2))))))) + (declare (type index ,len ,h2)) + (prog ((,index-var (rem (the hash ,sxhash) ,len)) + ,symbol-var ,ehash) + (declare (type (or index null) ,index-var)) + LOOP + (setq ,ehash (aref ,hash ,index-var)) + (cond ((eql ,ehash ,entry-hash) + (setq ,symbol-var (svref ,vec ,index-var)) + (let* ((,name (symbol-name ,symbol-var)) + (,name-len (length ,name))) + (declare (type index ,name-len)) + (when (and (= ,name-len ,length) + (string= ,string ,name + :end1 ,length + :end2 ,name-len)) + (go DOIT)))) + ((zerop ,ehash) + (setq ,index-var nil) + (go DOIT))) + (setq ,index-var (+ ,index-var ,h2)) + (when (>= ,index-var ,len) + (setq ,index-var (- ,index-var ,len))) + (go LOOP) + DOIT + (return (progn ,@forms)))))) ;;; Delete the entry for STRING in TABLE. The entry must exist. (defun nuke-symbol (table string) (declare (simple-string string)) (let* ((length (length string)) - (hash (%sxhash-simple-string string)) - (ehash (entry-hash length hash))) - (declare (type index length hash)) + (hash (%sxhash-simple-string string)) + (ehash (entry-hash length hash))) + (declare (type index length) + (type hash hash)) (with-symbol (index symbol table string length hash ehash) (setf (aref (package-hashtable-hash table) index) 1) (setf (aref (package-hashtable-table table) index) nil) - (incf (package-hashtable-deleted table))))) + (incf (package-hashtable-deleted table)))) + ;; If the table is less than one quarter full, halve its size and + ;; rehash the entries. + (let* ((size (package-hashtable-size table)) + (deleted (package-hashtable-deleted table)) + (used (- size + (package-hashtable-free table) + deleted))) + (declare (type fixnum size deleted used)) + (when (< used (truncate size 4)) + (resize-package-hashtable table (* used 2))))) -;;; Enter any new NICKNAMES for PACKAGE into *PACKAGE-NAMES*. -;;; If there is a conflict then give the user a chance to do -;;; something about it. -(defun enter-new-nicknames (package nicknames) +;;; Enter any new NICKNAMES for PACKAGE into *PACKAGE-NAMES*. If there is a +;;; conflict then give the user a chance to do something about it. Caller is +;;; responsible for having acquired the mutex via WITH-PACKAGES. +(defun %enter-new-nicknames (package nicknames) (declare (type list nicknames)) (dolist (n nicknames) (let* ((n (package-namify n)) - (found (gethash n *package-names*))) - (cond ((not found) - (setf (gethash n *package-names*) package) - (push n (package-%nicknames package))) - ((eq found package)) - ((string= (the string (package-%name found)) n) - ;; FIXME: This and the next error needn't have restarts. - (with-simple-restart (continue "Ignore this nickname.") - (error 'simple-package-error - :package package - :format-control "~S is a package name, so it cannot be a nickname for ~S." - :format-arguments (list n (package-%name package))))) - (t - (with-simple-restart (continue "Redefine this nickname.") - (error 'simple-package-error - :package package - :format-control "~S is already a nickname for ~S." - :format-arguments (list n (package-%name found)))) - (setf (gethash n *package-names*) package) - (push n (package-%nicknames package))))))) + (found (with-package-names (names) + (or (gethash n names) + (progn + (setf (gethash n names) package) + (push n (package-%nicknames package)) + package))))) + (cond ((eq found package)) + ((string= (the string (package-%name found)) n) + (cerror "Ignore this nickname." + 'simple-package-error + :package package + :format-control "~S is a package name, so it cannot be a nickname for ~S." + :format-arguments (list n (package-%name package)))) + (t + (cerror "Leave this nickname alone." + 'simple-package-error + :package package + :format-control "~S is already a nickname for ~S." + :format-arguments (list n (package-%name found)))))))) (defun make-package (name &key - (use '#.*default-package-use-list*) - nicknames - (internal-symbols 10) - (external-symbols 10)) + (use '#.*default-package-use-list*) + nicknames + (internal-symbols 10) + (external-symbols 10)) #!+sb-doc #.(format nil - "Make a new package having the specified NAME, NICKNAMES, and - USE list. :INTERNAL-SYMBOLS and :EXTERNAL-SYMBOLS are - estimates for the number of internal and external symbols which - will ultimately be present in the package. The default value of - USE is implementation-dependent, and in this implementation - it is ~S." - *default-package-use-list*) - - ;; Check for package name conflicts in name and nicknames, then - ;; make the package. - (when (find-package name) - ;; ANSI specifies that this error is correctable. - (cerror "Leave existing package alone." - "A package named ~S already exists" name)) - (let* ((name (package-namify name)) - (package (internal-make-package - :%name name - :internal-symbols (make-or-remake-package-hashtable - internal-symbols) - :external-symbols (make-or-remake-package-hashtable - external-symbols)))) - - ;; Do a USE-PACKAGE for each thing in the USE list so that checking for - ;; conflicting exports among used packages is done. - (if *in-package-init* - (push (list use package) *!deferred-use-packages*) - (use-package use package)) - - ;; FIXME: ENTER-NEW-NICKNAMES can fail (ERROR) if nicknames are illegal, - ;; which would leave us with possibly-bad side effects from the earlier - ;; USE-PACKAGE (e.g. this package on the used-by lists of other packages, - ;; but not in *PACKAGE-NAMES*, and possibly import side effects too?). - ;; Perhaps this can be solved by just moving ENTER-NEW-NICKNAMES before - ;; USE-PACKAGE, but I need to check what kinds of errors can be caused by - ;; USE-PACKAGE, too. - (enter-new-nicknames package nicknames) - (setf (gethash name *package-names*) package))) + "Make a new package having the specified NAME, NICKNAMES, and USE +list. :INTERNAL-SYMBOLS and :EXTERNAL-SYMBOLS are estimates for the number of +internal and external symbols which will ultimately be present in the package. +The default value of USE is implementation-dependent, and in this +implementation it is ~S." *default-package-use-list*) + (prog (clobber) + :restart + (when (find-package name) + ;; ANSI specifies that this error is correctable. + (cerror "Clobber existing package." + "A package named ~S already exists" name) + (setf clobber t)) + (with-package-graph () + ;; Check for race, signal the error outside the lock. + (when (and (not clobber) (find-package name)) + (go :restart)) + (let* ((name (package-namify name)) + (package (internal-make-package + :%name name + :internal-symbols (make-or-remake-package-hashtable + internal-symbols) + :external-symbols (make-or-remake-package-hashtable + external-symbols)))) + + ;; Do a USE-PACKAGE for each thing in the USE list so that checking for + ;; conflicting exports among used packages is done. + (if *in-package-init* + (push (list use package) *!deferred-use-packages*) + (use-package use package)) + + ;; FIXME: ENTER-NEW-NICKNAMES can fail (ERROR) if nicknames are illegal, + ;; which would leave us with possibly-bad side effects from the earlier + ;; USE-PACKAGE (e.g. this package on the used-by lists of other packages, + ;; but not in *PACKAGE-NAMES*, and possibly import side effects too?). + ;; Perhaps this can be solved by just moving ENTER-NEW-NICKNAMES before + ;; USE-PACKAGE, but I need to check what kinds of errors can be caused by + ;; USE-PACKAGE, too. + (%enter-new-nicknames package nicknames) + (return (setf (gethash name *package-names*) package)))) + (bug "never"))) ;;; Change the name if we can, blast any old nicknames and then ;;; add in any new ones. @@ -348,103 +797,147 @@ ;;; the package name if NAME is the same package that's referred to by PACKAGE. ;;; If it's a *different* package, we should probably signal an error. ;;; (perhaps (ERROR 'ANSI-WEIRDNESS ..):-) -(defun rename-package (package name &optional (nicknames ())) +(defun rename-package (package-designator name &optional (nicknames ())) #!+sb-doc "Changes the name and nicknames for a package." - (let* ((package (find-undeleted-package-or-lose package)) - (name (string name)) - (found (find-package name))) - (unless (or (not found) (eq found package)) - (error "A package named ~S already exists." name)) - (remhash (package-%name package) *package-names*) - (dolist (n (package-%nicknames package)) - (remhash n *package-names*)) - (setf (package-%name package) name) - (setf (gethash name *package-names*) package) - (setf (package-%nicknames package) ()) - (enter-new-nicknames package nicknames) + (let ((package nil)) + (tagbody :restart + (setq package (find-undeleted-package-or-lose package-designator)) + (let* ((name (package-namify name)) + (found (find-package name)) + (nicks (mapcar #'string nicknames))) + (unless (or (not found) (eq found package)) + (error 'simple-package-error + :package name + :format-control "A package named ~S already exists." + :format-arguments (list name))) + (with-single-package-locked-error () + (unless (and (string= name (package-name package)) + (null (set-difference nicks (package-nicknames package) + :test #'string=))) + (assert-package-unlocked package "rename as ~A~@[ with nickname~P ~ + ~{~A~^, ~}~]" + name (length nicks) nicks)) + (with-package-names (names) + ;; Check for race conditions now that we have the lock. + (unless (eq package (find-package package-designator)) + (go :restart)) + ;; Do the renaming. + (remhash (package-%name package) names) + (dolist (n (package-%nicknames package)) + (remhash n names)) + (setf (package-%name package) name + (gethash name names) package + (package-%nicknames package) ())) + (%enter-new-nicknames package nicknames)))) package)) -(defun delete-package (package-or-name) +(defun delete-package (package-designator) #!+sb-doc - "Delete the package-or-name from the package system data structures." - (let ((package (if (packagep package-or-name) - package-or-name - (find-package package-or-name)))) - (cond ((not package) - ;; This continuable error is required by ANSI. - (with-simple-restart (continue "Return NIL") - (error 'simple-package-error - :package package-or-name - :format-control "There is no package named ~S." - :format-arguments (list package-or-name)))) - ((not (package-name package)) ; already deleted - nil) - (t - (let ((use-list (package-used-by-list package))) - (when use-list - ;; This continuable error is specified by ANSI. - (with-simple-restart - (continue "Remove dependency in other packages.") - (error 'simple-package-error - :package package - :format-control - "Package ~S is used by package(s):~% ~S" - :format-arguments - (list (package-name package) - (mapcar #'package-name use-list)))) - (dolist (p use-list) - (unuse-package package p)))) - (dolist (used (package-use-list package)) - (unuse-package used package)) - (do-symbols (sym package) - (unintern sym package)) - (remhash (package-name package) *package-names*) - (dolist (nick (package-nicknames package)) - (remhash nick *package-names*)) - (setf (package-%name package) nil - ;; Setting PACKAGE-%NAME to NIL is required in order to - ;; make PACKAGE-NAME return NIL for a deleted package as - ;; ANSI requires. Setting the other slots to NIL - ;; and blowing away the PACKAGE-HASHTABLES is just done - ;; for tidiness and to help the GC. - (package-%nicknames package) nil - (package-%use-list package) nil - (package-tables package) nil - (package-%shadowing-symbols package) nil - (package-internal-symbols package) - (make-or-remake-package-hashtable 0) - (package-external-symbols package) - (make-or-remake-package-hashtable 0)) - t)))) + "Delete the package designated by PACKAGE-DESIGNATOR from the package + system data structures." + (tagbody :restart + (let ((package (find-package package-designator))) + (cond ((not package) + ;; This continuable error is required by ANSI. + (cerror + "Return ~S." + (make-condition + 'simple-package-error + :package package-designator + :format-control "There is no package named ~S." + :format-arguments (list package-designator)) + (return-from delete-package nil))) + ((not (package-name package)) ; already deleted + (return-from delete-package nil)) + (t + (with-single-package-locked-error + (:package package "deleting package ~A" package) + (let ((use-list (package-used-by-list package))) + (when use-list + ;; This continuable error is specified by ANSI. + (cerror + "Remove dependency in other packages." + (make-condition + 'simple-package-error + :package package + :format-control + "~@" + :format-arguments (list (package-name package) + (length use-list) + (mapcar #'package-name use-list)))) + (dolist (p use-list) + (unuse-package package p)))) + (dolist (p (package-implements-list package)) + (remove-implementation-package package p)) + (with-package-graph () + ;; Check for races, restart if necessary. + (let ((package2 (find-package package-designator))) + (when (or (neq package package2) (package-used-by-list package2)) + (go :restart))) + (dolist (used (package-use-list package)) + (unuse-package used package)) + (dolist (namer (package-%locally-nicknamed-by package)) + (setf (package-%local-nicknames namer) + (delete package (package-%local-nicknames namer) :key #'cdr))) + (setf (package-%locally-nicknamed-by package) nil) + (dolist (cell (package-%local-nicknames package)) + (let ((actual (cdr cell))) + (setf (package-%locally-nicknamed-by actual) + (delete package (package-%locally-nicknamed-by actual))))) + (setf (package-%local-nicknames package) nil) + (do-symbols (sym package) + (unintern sym package)) + (with-package-names (names) + (remhash (package-name package) names) + (dolist (nick (package-nicknames package)) + (remhash nick names)) + (setf (package-%name package) nil + ;; Setting PACKAGE-%NAME to NIL is required in order to + ;; make PACKAGE-NAME return NIL for a deleted package as + ;; ANSI requires. Setting the other slots to NIL + ;; and blowing away the PACKAGE-HASHTABLES is just done + ;; for tidiness and to help the GC. + (package-%nicknames package) nil)) + (setf (package-%use-list package) nil + (package-tables package) nil + (package-%shadowing-symbols package) nil + (package-internal-symbols package) + (make-or-remake-package-hashtable 0) + (package-external-symbols package) + (make-or-remake-package-hashtable 0))) + (return-from delete-package t))))))) (defun list-all-packages () #!+sb-doc "Return a list of all existing packages." (let ((res ())) - (maphash (lambda (k v) - (declare (ignore k)) - (pushnew v res)) - *package-names*) + (with-package-names (names) + (maphash (lambda (k v) + (declare (ignore k)) + (pushnew v res)) + names)) res)) (defun intern (name &optional (package (sane-package))) #!+sb-doc - "Return a symbol having the specified name, creating it if necessary." + "Return a symbol in PACKAGE having the specified NAME, creating it + if necessary." ;; We just simple-stringify the name and call INTERN*, where the real ;; logic is. (let ((name (if (simple-string-p name) - name - (coerce name 'simple-string)))) + name + (coerce name 'simple-string))) + (package (find-undeleted-package-or-lose package))) (declare (simple-string name)) - (intern* name - (length name) - (find-undeleted-package-or-lose package)))) + (intern* name + (length name) + package))) (defun find-symbol (name &optional (package (sane-package))) #!+sb-doc - "Return the symbol named String in Package. If such a symbol is found - then the second value is :internal, :external or :inherited to indicate + "Return the symbol named STRING in PACKAGE. If such a symbol is found + then the second value is :INTERNAL, :EXTERNAL or :INHERITED to indicate how the symbol is accessible. If no symbol is found then both values are NIL." ;; We just simple-stringify the name and call FIND-SYMBOL*, where the @@ -452,124 +945,286 @@ (let ((name (if (simple-string-p name) name (coerce name 'simple-string)))) (declare (simple-string name)) (find-symbol* name - (length name) - (find-undeleted-package-or-lose package)))) + (length name) + (find-undeleted-package-or-lose package)))) ;;; If the symbol named by the first LENGTH characters of NAME doesn't exist, ;;; then create it, special-casing the keyword package. -(defun intern* (name length package) +(defun intern* (name length package &key no-copy) (declare (simple-string name)) (multiple-value-bind (symbol where) (find-symbol* name length package) - (if where - (values symbol where) - (let ((symbol (make-symbol (subseq name 0 length)))) - (%set-symbol-package symbol package) - (cond ((eq package *keyword-package*) - (add-symbol (package-external-symbols package) symbol) - (%set-symbol-value symbol symbol)) - (t - (add-symbol (package-internal-symbols package) symbol))) - (values symbol nil))))) + (cond (where + (values symbol where)) + (t + ;; Let's try again with a lock: the common case has the + ;; symbol already interned, handled by the first leg of the + ;; COND, but in case another thread is interning in + ;; parallel we need to check after grabbing the lock. + (with-package-graph () + (setf (values symbol where) (find-symbol* name length package)) + (if where + (values symbol where) + (let ((symbol-name (cond (no-copy + (aver (= (length name) length)) + name) + (t + ;; This so that SUBSEQ is inlined, + ;; because we need it fixed for cold init. + (string-dispatch + ((simple-array base-char (*)) + (simple-array character (*))) + name + (declare (optimize speed)) + (subseq name 0 length)))))) + (with-single-package-locked-error + (:package package "interning ~A" symbol-name) + (let ((symbol (make-symbol symbol-name))) + (%set-symbol-package symbol package) + (cond + ((eq package *keyword-package*) + (%set-symbol-value symbol symbol) + (add-symbol (package-external-symbols package) symbol)) + (t + (add-symbol (package-internal-symbols package) symbol))) + (values symbol nil)))))))))) ;;; Check internal and external symbols, then scan down the list -;;; of hashtables for inherited symbols. When an inherited symbol -;;; is found pull that table to the beginning of the list. +;;; of hashtables for inherited symbols. (defun find-symbol* (string length package) (declare (simple-string string) - (type index length)) + (type index length)) (let* ((hash (%sxhash-simple-substring string length)) - (ehash (entry-hash length hash))) - (declare (type index hash ehash)) + (ehash (entry-hash length hash))) + (declare (type hash hash ehash)) (with-symbol (found symbol (package-internal-symbols package) - string length hash ehash) + string length hash ehash) (when found - (return-from find-symbol* (values symbol :internal)))) + (return-from find-symbol* (values symbol :internal)))) (with-symbol (found symbol (package-external-symbols package) - string length hash ehash) + string length hash ehash) (when found - (return-from find-symbol* (values symbol :external)))) + (return-from find-symbol* (values symbol :external)))) (let ((head (package-tables package))) (do ((prev head table) - (table (cdr head) (cdr table))) - ((null table) (values nil nil)) - (with-symbol (found symbol (car table) string length hash ehash) - (when found - (unless (eq prev head) - (shiftf (cdr prev) (cdr table) (cdr head) table)) - (return-from find-symbol* (values symbol :inherited)))))))) - -;;; Similar to Find-Symbol, but only looks for an external symbol. + (table (cdr head) (cdr table))) + ((null table) (values nil nil)) + (with-symbol (found symbol (car table) string length hash ehash) + (when found + ;; At this point we used to move the table to the + ;; beginning of the list, probably on the theory that we'd + ;; soon be looking up further items there. Unfortunately + ;; that was very much non-thread safe. Since the failure + ;; mode was nasty (corruption of the package in a way + ;; which would make symbol lookups loop infinitely) and it + ;; would be triggered just by doing reads to a resource + ;; that users can't do their own locking on, that code has + ;; been removed. If we ever add locking to packages, + ;; resurrecting that code might make sense, even though it + ;; didn't seem to have much of an performance effect in + ;; normal use. + ;; + ;; -- JES, 2006-09-13 + (return-from find-symbol* (values symbol :inherited)))))))) + +;;; Similar to FIND-SYMBOL, but only looks for an external symbol. ;;; This is used for fast name-conflict checking in this file and symbol ;;; printing in the printer. (defun find-external-symbol (string package) (declare (simple-string string)) (let* ((length (length string)) - (hash (%sxhash-simple-string string)) - (ehash (entry-hash length hash))) - (declare (type index length hash)) + (hash (%sxhash-simple-string string)) + (ehash (entry-hash length hash))) + (declare (type index length) + (type hash hash)) (with-symbol (found symbol (package-external-symbols package) - string length hash ehash) + string length hash ehash) (values symbol found)))) +(defun print-symbol-with-prefix (stream symbol colon at) + #!+sb-doc + "For use with ~/: Write SYMBOL to STREAM as if it is not accessible from + the current package." + (declare (ignore colon at)) + ;; Only keywords should be accessible from the keyword package, and + ;; keywords are always printed with colons, so this guarantees that the + ;; symbol will not be printed without a prefix. + (let ((*package* *keyword-package*)) + (write symbol :stream stream :escape t))) + +(define-condition name-conflict (reference-condition package-error) + ((function :initarg :function :reader name-conflict-function) + (datum :initarg :datum :reader name-conflict-datum) + (symbols :initarg :symbols :reader name-conflict-symbols)) + (:default-initargs :references (list '(:ansi-cl :section (11 1 1 2 5)))) + (:report + (lambda (c s) + (format s "~@<~S ~S causes name-conflicts in ~S between the ~ + following symbols:~2I~@:_~ + ~{~/sb-impl::print-symbol-with-prefix/~^, ~}~:@>" + (name-conflict-function c) + (name-conflict-datum c) + (package-error-package c) + (name-conflict-symbols c))))) + +(defun name-conflict (package function datum &rest symbols) + (flet ((importp (c) + (declare (ignore c)) + (eq 'import function)) + (use-or-export-p (c) + (declare (ignore c)) + (or (eq 'use-package function) + (eq 'export function))) + (old-symbol () + (car (remove datum symbols)))) + (let ((pname (package-name package))) + (restart-case + (error 'name-conflict :package package :symbols symbols + :function function :datum datum) + ;; USE-PACKAGE and EXPORT + (keep-old () + :report (lambda (s) + (ecase function + (export + (format s "Keep ~S accessible in ~A (shadowing ~S)." + (old-symbol) pname datum)) + (use-package + (format s "Keep symbols already accessible ~A (shadowing others)." + pname)))) + :test use-or-export-p + (dolist (s (remove-duplicates symbols :test #'string=)) + (shadow (symbol-name s) package))) + (take-new () + :report (lambda (s) + (ecase function + (export + (format s "Make ~S accessible in ~A (uninterning ~S)." + datum pname (old-symbol))) + (use-package + (format s "Make newly exposed symbols accessible in ~A, ~ + uninterning old ones." + pname)))) + :test use-or-export-p + (dolist (s symbols) + (when (eq s (find-symbol (symbol-name s) package)) + (unintern s package)))) + ;; IMPORT + (shadowing-import-it () + :report (lambda (s) + (format s "Shadowing-import ~S, uninterning ~S." + datum (old-symbol))) + :test importp + (shadowing-import datum package)) + (dont-import-it () + :report (lambda (s) + (format s "Don't import ~S, keeping ~S." + datum + (car (remove datum symbols)))) + :test importp) + ;; General case. This is exposed via SB-EXT. + (resolve-conflict (chosen-symbol) + :report "Resolve conflict." + :interactive + (lambda () + (let* ((len (length symbols)) + (nlen (length (write-to-string len :base 10))) + (*print-pretty* t)) + (format *query-io* "~&~@