X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcode%2Feval.lisp;h=f8ef5b0bccab8ff03939912a23e9156f7c977eeb;hb=5d6eb238f2d59e6df825cb03aefe2976a130c6ec;hp=879125c71dde4cc9b008e19a86076459d6fead73;hpb=cea4896b2482b7b2b429c1631d774b4cfbc0efba;p=sbcl.git diff --git a/src/code/eval.lisp b/src/code/eval.lisp index 879125c..f8ef5b0 100644 --- a/src/code/eval.lisp +++ b/src/code/eval.lisp @@ -1,3 +1,5 @@ +;;;; EVAL and friends + ;;;; This software is part of the SBCL system. See the README file for ;;;; more information. ;;;; @@ -7,9 +9,235 @@ ;;;; provided with absolutely no warranty. See the COPYING and CREDITS ;;;; files for more information. -(in-package "SB!EVAL") +(in-package "SB!IMPL") + +;;; general case of EVAL (except in that it can't handle toplevel +;;; EVAL-WHEN magic properly): Delegate to #'COMPILE. +(defun %eval (expr lexenv) + (funcall (sb!c:compile-in-lexenv + (gensym "EVAL-TMPFUN-") + `(lambda () + ,expr) + lexenv))) + +;;; Handle PROGN and implicit PROGN. +(defun eval-progn-body (progn-body lexenv) + (unless (list-with-length-p progn-body) + (let ((*print-circle* t)) + (error 'simple-program-error + :format-control + "~@" + :format-arguments (list progn-body)))) + ;; Note: + ;; * We can't just use (MAP NIL #'EVAL PROGN-BODY) here, because we + ;; need to take care to return all the values of the final EVAL. + ;; * It's left as an exercise to the reader to verify that this + ;; gives the right result when PROGN-BODY is NIL, because + ;; (FIRST NIL) = (REST NIL) = NIL. + (do* ((i progn-body rest-i) + (rest-i (rest i) (rest i))) + (nil) + (if rest-i ; if not last element of list + (eval-in-lexenv (first i) lexenv) + (return (eval-in-lexenv (first i) lexenv))))) + +(defun eval (original-exp) + #!+sb-doc + "Evaluate the argument in a null lexical environment, returning the + result or results." + (eval-in-lexenv original-exp (make-null-lexenv))) + +;;; Pick off a few easy cases, and the various top level EVAL-WHEN +;;; magical cases, and call %EVAL for the rest. +(defun eval-in-lexenv (original-exp lexenv) + (declare (optimize (safety 1))) + ;; (aver (lexenv-simple-p lexenv)) + (let ((exp (macroexpand original-exp lexenv))) + (typecase exp + (symbol + (ecase (info :variable :kind exp) + (:constant + (values (info :variable :constant-value exp))) + ((:special :global) + (symbol-value exp)) + ;; FIXME: This special case here is a symptom of non-ANSI + ;; weirdness in SBCL's ALIEN implementation, which could + ;; cause problems for e.g. code walkers. It'd probably be + ;; good to ANSIfy it by making alien variable accessors into + ;; ordinary forms, e.g. (SB-UNIX:ENV) and (SETF SB-UNIX:ENV), + ;; instead of magical symbols, e.g. plain SB-UNIX:ENV. Then + ;; if the old magical-symbol syntax is to be retained for + ;; compatibility, it can be implemented with + ;; DEFINE-SYMBOL-MACRO, keeping the code walkers happy. + (:alien + (%eval original-exp lexenv)))) + (list + (let ((name (first exp)) + (n-args (1- (length exp)))) + (case name + ((function) + (unless (= n-args 1) + (error "wrong number of args to FUNCTION:~% ~S" exp)) + (let ((name (second exp))) + (if (and (or (atom name) + (and (consp name) + (eq (car name) 'setf))) + (not (consp (let ((sb!c:*lexenv* lexenv)) + (sb!c:lexenv-find name funs))))) + (fdefinition name) + (%eval original-exp lexenv)))) + ((quote) + (unless (= n-args 1) + (error "wrong number of args to QUOTE:~% ~S" exp)) + (second exp)) + (setq + (unless (evenp n-args) + (error "odd number of args to SETQ:~% ~S" exp)) + (unless (zerop n-args) + (do ((name (cdr exp) (cddr name))) + ((null name) + (do ((args (cdr exp) (cddr args))) + ((null (cddr args)) + ;; We duplicate the call to SET so that the + ;; correct value gets returned. + (set (first args) (eval (second args)))) + (set (first args) (eval (second args))))) + (let ((symbol (first name))) + (case (info :variable :kind symbol) + ;; FIXME: I took out the *TOPLEVEL-AUTO-DECLARE* + ;; test here, and removed the *TOPLEVEL-AUTO-DECLARE* + ;; variable; the code should now act as though that + ;; variable is NIL. This should be tested.. + (:special) + (t (return (%eval original-exp lexenv)))))))) + ((progn) + (eval-progn-body (rest exp) lexenv)) + ((eval-when) + ;; FIXME: DESTRUCTURING-BIND returns ARG-COUNT-ERROR + ;; instead of PROGRAM-ERROR when there's something wrong + ;; with the syntax here (e.g. missing SITUATIONS). This + ;; could be fixed by hand-crafting clauses to catch and + ;; report each possibility, but it would probably be + ;; cleaner to write a new macro + ;; DESTRUCTURING-BIND-PROGRAM-SYNTAX which does + ;; DESTRUCTURING-BIND and promotes any mismatch to + ;; PROGRAM-ERROR, then to use it here and in (probably + ;; dozens of) other places where the same problem arises. + (destructuring-bind (eval-when situations &rest body) exp + (declare (ignore eval-when)) + (multiple-value-bind (ct lt e) + (sb!c:parse-eval-when-situations situations) + ;; CLHS 3.8 - Special Operator EVAL-WHEN: The use of + ;; the situation :EXECUTE (or EVAL) controls whether + ;; evaluation occurs for other EVAL-WHEN forms; that + ;; is, those that are not top level forms, or those in + ;; code processed by EVAL or COMPILE. If the :EXECUTE + ;; situation is specified in such a form, then the + ;; body forms are processed as an implicit PROGN; + ;; otherwise, the EVAL-WHEN form returns NIL. + (declare (ignore ct lt)) + (when e + (eval-progn-body body lexenv))))) + ((locally) + (multiple-value-bind (body decls) (parse-body (rest exp) nil) + (let ((lexenv + ;; KLUDGE: Uh, yeah. I'm not anticipating + ;; winning any prizes for this code, which was + ;; written on a "let's get it to work" basis. + ;; These seem to be the variables that need + ;; bindings for PROCESS-DECLS to work + ;; (*FREE-FUNS* and *FREE-VARS* so that + ;; references to free functions and variables in + ;; the declarations can be noted; + ;; *UNDEFINED-WARNINGS* so that warnings about + ;; undefined things can be accumulated [and then + ;; thrown away, as it happens]). -- CSR, 2002-10-24 + (let ((sb!c:*lexenv* lexenv) + (sb!c::*free-funs* (make-hash-table :test 'equal)) + (sb!c::*free-vars* (make-hash-table :test 'eq)) + (sb!c::*undefined-warnings* nil)) + (sb!c::process-decls decls + nil nil + (sb!c::make-continuation) + lexenv)))) + (eval-progn-body body lexenv)))) + ((macrolet) + (destructuring-bind (definitions &rest body) + (rest exp) + ;; FIXME: shared code with FUNCALL-IN-FOOMACROLET-LEXENV + (declare (type list definitions)) + (unless (= (length definitions) + (length (remove-duplicates definitions :key #'first))) + (style-warn "duplicate definitions in ~S" definitions)) + (let ((lexenv + (sb!c::make-lexenv + :default lexenv + :funs (mapcar + (sb!c::macrolet-definitionize-fun + :eval + ;; I'm not sure that this is the correct + ;; LEXENV to be compiling local macros + ;; in... + lexenv) + definitions)))) + (eval-in-lexenv `(locally ,@body) lexenv)))) + ((symbol-macrolet) + (destructuring-bind (definitions &rest body) + (rest exp) + ;; FIXME: shared code with FUNCALL-IN-FOOMACROLET-LEXENV + (declare (type list definitions)) + (unless (= (length definitions) + (length (remove-duplicates definitions :key #'first))) + (style-warn "duplicate definitions in ~S" definitions)) + (let ((lexenv + (sb!c::make-lexenv + :default lexenv + :vars (mapcar + (sb!c::symbol-macrolet-definitionize-fun + :eval) + definitions)))) + (eval-in-lexenv `(locally ,@body) lexenv)))) + (t + (if (and (symbolp name) + (eq (info :function :kind name) :function)) + (collect ((args)) + (dolist (arg (rest exp)) + (args (eval-in-lexenv arg lexenv))) + (apply (symbol-function name) (args))) + (%eval exp lexenv)))))) + (t + exp)))) + +;;; miscellaneous full function definitions of things which are +;;; ordinarily handled magically by the compiler + +(defun apply (function arg &rest arguments) + #!+sb-doc + "Apply FUNCTION to a list of arguments produced by evaluating ARGUMENTS in + the manner of LIST*. That is, a list is made of the values of all but the + last argument, appended to the value of the last argument, which must be a + list." + (cond ((atom arguments) + (apply function arg)) + ((atom (cdr arguments)) + (apply function (cons arg (car arguments)))) + (t (do* ((a1 arguments a2) + (a2 (cdr arguments) (cdr a2))) + ((atom (cdr a2)) + (rplacd a1 (car a2)) + (apply function (cons arg arguments))))))) + +(defun funcall (function &rest arguments) + #!+sb-doc + "Call FUNCTION with the given ARGUMENTS." + (apply function arguments)) + +(defun values (&rest values) + #!+sb-doc + "Return all arguments, in order, as values." + (values-list values)) -;;; This flag is used by EVAL-WHEN to keep track of when code has already been -;;; evaluated so that it can avoid multiple evaluation of nested EVAL-WHEN -;;; (COMPILE)s. -(defvar *already-evaled-this* nil) +(defun values-list (list) + #!+sb-doc + "Return all of the elements of LIST, in order, as values." + (values-list list))