X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Feval.lisp;h=da49162b697841e4fc4ed43dc515fbd0169702a1;hb=5277a0cbf1a72243cad6808883a4847acefc8e6b;hp=900e1aba850f59a938894c6c4560a6c9eca8833d;hpb=95a6db7329b91dd90d165dd4057b9b5098d34aa2;p=sbcl.git diff --git a/src/code/eval.lisp b/src/code/eval.lisp index 900e1ab..da49162 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 +9,210 @@ ;;;; 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) + (funcall (compile (gensym "EVAL-TMPFUN-") + `(lambda () + + ;; The user can reasonably expect that the + ;; interpreter will be safe. + (declare (optimize (safety 3))) + + ;; It's also good if the interpreter doesn't + ;; spend too long thinking about each input + ;; form, since if the user'd wanted the + ;; tradeoff to favor quality of compiled code + ;; over compilation speed, he'd've explicitly + ;; asked for compilation. + (declare (optimize (compilation-speed 2))) + + ;; Other properties are relatively unimportant. + (declare (optimize (speed 1) (debug 1) (space 1))) + + ,expr)))) + +;;; Handle PROGN and implicit PROGN. +(defun eval-progn-body (progn-body) + (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 (first i)) + (return (eval (first i)))))) + +;;; Pick off a few easy cases, and the various top level EVAL-WHEN +;;; magical cases, and call %EVAL for the rest. +(defun eval (original-exp) + #!+sb-doc + "Evaluate the argument in a null lexical environment, returning the + result or results." + (declare (optimize (safety 1))) + (let ((exp (macroexpand original-exp))) + (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)))) + (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 (or (atom name) + (and (consp name) + (eq (car name) 'setf))) + (fdefinition name) + (%eval original-exp)))) + (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)))))))) + ((progn) + (eval-progn-body (rest exp))) + ((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))))) + (t + (if (and (symbolp name) + (eq (info :function :kind name) :function)) + (collect ((args)) + (dolist (arg (rest exp)) + (args (eval arg))) + (apply (symbol-function name) (args))) + (%eval original-exp)))))) + (t + exp)))) + +(defun function-lambda-expression (fun) + "Return (VALUES DEFINING-LAMBDA-EXPRESSION CLOSURE-P NAME), where + DEFINING-LAMBDA-EXPRESSION is NIL if unknown, or a suitable argument + to COMPILE otherwise, CLOSURE-P is non-NIL if the function's definition + might have been enclosed in some non-null lexical environment, and + NAME is some name (for debugging only) or NIL if there is no name." + (declare (type function fun)) + (let* ((fun (%simple-fun-self fun)) + (name (%simple-fun-name fun)) + (code (sb!di::fun-code-header fun)) + (info (sb!kernel:%code-debug-info code))) + (if info + (let ((source (first (sb!c::compiled-debug-info-source info)))) + (cond ((and (eq (sb!c::debug-source-from source) :lisp) + (eq (sb!c::debug-source-info source) fun)) + (values (second (svref (sb!c::debug-source-name source) 0)) + nil name)) + ((stringp name) + (values nil t name)) + (t + (let ((exp (fun-name-inline-expansion name))) + (if exp + (values exp nil name) + (values nil t name)))))) + (values nil t name)))) + +;;; 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))