X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Feval.lisp;h=977cd3d74989fd93e92d419d6aa5a44d53291c75;hb=4ba392170e98744f0ef0b8e08a5d42b988f1d0c9;hp=900e1aba850f59a938894c6c4560a6c9eca8833d;hpb=95a6db7329b91dd90d165dd4057b9b5098d34aa2;p=sbcl.git diff --git a/src/code/eval.lisp b/src/code/eval.lisp index 900e1ab..977cd3d 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 +9,317 @@ ;;;; provided with absolutely no warranty. See the COPYING and CREDITS ;;;; files for more information. -(in-package "SB!EVAL") +(in-package "SB!IMPL") + +(defparameter *eval-calls* 0) + +(defun !eval-cold-init () + (setf *eval-calls* 0 + *evaluator-mode* :compile) + #!+sb-eval + (setf sb!eval::*eval-level* -1 + sb!eval::*eval-verbose* nil)) + +(defvar *eval-source-context* nil) + +(defvar *eval-tlf-index* nil) +(defvar *eval-source-info* nil) + +;;;; Turns EXPR into a lambda-form we can pass to COMPILE. Returns +;;;; a secondary value of T if we must call the resulting function +;;;; to evaluate EXPR -- if EXPR is already a lambda form, there's +;;;; no need. +(defun make-eval-lambda (expr) + (if (typep expr `(cons (member lambda named-lambda lambda-with-lexenv))) + (values expr nil) + (values `(lambda () + ;; why PROGN? So that attempts to eval free declarations + ;; signal errors rather than return NIL. -- CSR, 2007-05-01 + (progn ,expr)) + t))) + +;;; general case of EVAL (except in that it can't handle toplevel +;;; EVAL-WHEN magic properly): Delegate to #'COMPILE. +(defun %simple-eval (expr lexenv) + (multiple-value-bind (lambda call) (make-eval-lambda expr) + (let ((fun + ;; This tells the compiler where the lambda comes from, in case it + ;; wants to report any problems. + (let ((sb!c::*source-form-context-alist* + (acons lambda *eval-source-context* + sb!c::*source-form-context-alist*))) + (handler-bind (;; Compiler notes just clutter up the REPL: + ;; anyone caring about performance should not + ;; be using EVAL. + (compiler-note #'muffle-warning)) + (sb!c:compile-in-lexenv + nil lambda lexenv *eval-source-info* *eval-tlf-index* (not call)))))) + (declare (function fun)) + (if call + (funcall fun) + fun)))) + +;;; Handle PROGN and implicit PROGN. +(defun simple-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 + (simple-eval-in-lexenv (first i) lexenv) + (return (simple-eval-in-lexenv (first i) lexenv))))) + +(defun simple-eval-locally (exp lexenv &key vars) + (multiple-value-bind (body decls) + (parse-body (rest exp) :doc-string-allowed 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)) + ;; FIXME: VALUES declaration + (sb!c::process-decls decls + vars + nil + :lexenv lexenv + :context :eval)))) + (simple-eval-progn-body body lexenv)))) + +;;;; EVAL-ERROR +;;;; +;;;; Analogous to COMPILER-ERROR, but simpler. + +(define-condition eval-error (encapsulated-condition) + () + (:report (lambda (condition stream) + (print-object (encapsulated-condition condition) stream)))) + +(defun eval-error (condition) + (signal 'eval-error :condition condition) + (bug "Unhandled EVAL-ERROR")) + +;;; Pick off a few easy cases, and the various top level EVAL-WHEN +;;; magical cases, and call %SIMPLE-EVAL for the rest. +(defun simple-eval-in-lexenv (original-exp lexenv) + (declare (optimize (safety 1))) + ;; (aver (lexenv-simple-p lexenv)) + (incf *eval-calls*) + (sb!c:with-compiler-error-resignalling + (let ((exp (macroexpand original-exp lexenv))) + (handler-bind ((eval-error + (lambda (condition) + (error 'interpreted-program-error + :condition (encapsulated-condition condition) + :form exp)))) + (typecase exp + (symbol + (ecase (info :variable :kind exp) + ((:special :global :constant :unknown) + (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 + (sb!alien-internals:alien-value 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 (and (legal-fun-name-p name) + (not (consp (let ((sb!c:*lexenv* lexenv)) + (sb!c:lexenv-find name funs))))) + (%coerce-name-to-fun name) + ;; FIXME: This is a bit wasteful: it would be nice to call + ;; COMPILE-IN-LEXENV with the lambda-form directly, but + ;; getting consistent source context and muffling compiler notes + ;; is easier this way. + (%simple-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) + (simple-eval-in-lexenv (second args) lexenv))) + (set (first args) + (simple-eval-in-lexenv (second args) lexenv)))) + (let ((symbol (first name))) + (case (info :variable :kind symbol) + (:special) + (t (return (%simple-eval original-exp lexenv)))) + (unless (type= (info :variable :type symbol) + *universal-type*) + ;; let the compiler deal with type checking + (return (%simple-eval original-exp lexenv))))))) + ((progn) + (simple-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 + (simple-eval-progn-body body lexenv))))) + ((locally) + (simple-eval-locally exp lexenv)) + ((macrolet) + (destructuring-bind (definitions &rest body) + (rest exp) + (let ((lexenv + (let ((sb!c:*lexenv* lexenv)) + (sb!c::funcall-in-macrolet-lexenv + definitions + (lambda (&key funs) + (declare (ignore funs)) + sb!c:*lexenv*) + :eval)))) + (simple-eval-locally `(locally ,@body) lexenv)))) + ((symbol-macrolet) + (destructuring-bind (definitions &rest body) (rest exp) + (multiple-value-bind (lexenv vars) + (let ((sb!c:*lexenv* lexenv)) + (sb!c::funcall-in-symbol-macrolet-lexenv + definitions + (lambda (&key vars) + (values sb!c:*lexenv* vars)) + :eval)) + (simple-eval-locally `(locally ,@body) lexenv :vars vars)))) + ((if) + (destructuring-bind (test then &optional else) (rest exp) + (eval-in-lexenv (if (eval-in-lexenv test lexenv) + then + else) + lexenv))) + ((let let*) + (%simple-eval exp 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))) + (%simple-eval exp lexenv)))))) + (t + exp)))))) + +(defun eval-in-lexenv (exp lexenv) + #!+sb-eval + (if (eq *evaluator-mode* :compile) + (simple-eval-in-lexenv exp lexenv) + (sb!eval:eval-in-native-environment exp lexenv)) + #!-sb-eval + (simple-eval-in-lexenv exp lexenv)) + +(defun eval (original-exp) + #!+sb-doc + "Evaluate the argument in a null lexical environment, returning the + result or results." + (let ((*eval-source-context* original-exp) + (*eval-tlf-index* nil) + (*eval-source-info* nil)) + (eval-in-lexenv original-exp (make-null-lexenv)))) + +(defun eval-tlf (original-exp tlf-index &optional (lexenv (make-null-lexenv))) + (let ((*eval-source-context* original-exp) + (*eval-tlf-index* tlf-index) + (*eval-source-info* sb!c::*source-info*)) + (eval-in-lexenv original-exp lexenv))) + +;;; 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." + (declare (truly-dynamic-extent 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))