Language/OS - Multiplatform Resource Library/LANGUAGE OS.iso/pcl/src-16f.lha/compiler/eval-comp.lisp

Text File | 1992-12-09 | 11.4 KB | 309 lines

;;; -*- Package: C; Log: C.Log -*-
;;;
;;; **********************************************************************
;;; This code was written as part of the CMU Common Lisp project at
;;; Carnegie Mellon University, and has been placed in the public domain.
;;; If you want to use this code or any part of CMU Common Lisp, please contact
;;; Scott Fahlman or [e-mail].
;;;
(ext:file-comment
  "$Header: eval-comp.lisp,v 1.22 92/11/25 10:32:12 wlott Exp $")
;;;
;;; **********************************************************************
;;;
;;; This file represents the current state of on-going development on compiler
;;; hooks for an interpreter that takes the compiler's IR1 of a program.
;;;
;;; Written by Bill Chiles.
;;;

(in-package "C")

(proclaim '(special *constants* *free-variables* *compile-component*
            *code-vector* *next-location* *result-fixups*
            *free-functions* *source-paths* *failed-optimizations*
            *seen-blocks* *seen-functions* *list-conflicts-table*
            *continuation-number* *continuation-numbers*
            *number-continuations* *tn-id* *tn-ids* *id-tns*
            *label-ids* *label-id* *id-labels*
            *compiler-error-count*
            *compiler-warning-count* *compiler-note-count*
            *compiler-error-output* *compiler-error-bailout*
            *compiler-trace-output*
            *last-source-context* *last-original-source*
            *last-source-form* *last-format-string* *last-format-args*
            *last-message-count* *check-consistency*
            *all-components* *converting-for-interpreter*
            *source-info* *block-compile* *current-path*
            *current-component* *lexical-environment*))

(export '(compile-for-eval lambda-eval-info-frame-size
      lambda-eval-info-args-passed lambda-eval-info-entries
      lambda-eval-info-function entry-node-info-st-top
      entry-node-info-nlx-tag))


;;; COMPILE-FOR-EVAL -- Public.
;;;
;;; This translates form into the compiler's IR1 and performs environment
;;; analysis.  It is sort of a combination of NCOMPILE-FILE, SUB-COMPILE-FILE,
;;; COMPILE-TOP-LEVEL, and COMPILE-COMPONENT.
;;;
(defun compile-for-eval (form quietly)
  (with-ir1-namespace
    (let* ((*block-compile* nil)
       (*lexical-environment* (make-null-environment))
       ;;
       (*compiler-error-output*
        (if quietly
        (make-broadcast-stream)
        *error-output*))
       (*compiler-trace-output* nil)
       (*compiler-error-bailout*
        #'(lambda () (error "Fatal error, aborting evaluation.")))
       ;;
       (*current-path* nil)
       (*last-source-context* nil)
       (*last-original-source* nil)
       (*last-source-form* nil)
       (*last-format-string* nil)
       (*last-format-args* nil)
       (*last-message-count* 0)
       ;;
       (*compiler-error-count* 0)
       (*compiler-warning-count* 0)
       (*compiler-note-count* 0)
       (*source-info* (make-lisp-source-info form))
       (*converting-for-interpreter* t)
       (*gensym-counter* 0))

      (clear-stuff nil)
      (find-source-paths form 0)
      ;;
      ;; This LET comes from COMPILE-TOP-LEVEL.
      ;; The noted DOLIST is a splice from a call that COMPILE-TOP-LEVEL makes.
      (with-compilation-unit ()
    (let ((lambdas (list (ir1-top-level form '(original-source-start 0 0)
                        t))))
      (declare (list lambdas))
      (dolist (lambda lambdas)
        (let* ((component
            (block-component (node-block (lambda-bind lambda))))
           (*all-components* (list component)))
          (local-call-analyze component)))
      (multiple-value-bind (components top-components)
                   (find-initial-dfo lambdas)
        (let ((*all-components* (append components top-components)))
          (when *check-consistency*
        (check-ir1-consistency *all-components*))
          ;;
          ;; This DOLIST body comes from the beginning of
          ;; COMPILE-COMPONENT.
          (dolist (component *all-components*)
        (ir1-finalize component)
        (let ((*compile-component* component))
          (environment-analyze component))
        (annotate-component-for-eval component))
        (when *check-consistency*
          (check-ir1-consistency *all-components*))))
      (car lambdas))))))


;;;; Annotating IR1 for interpretation.

(defstruct (lambda-eval-info (:print-function print-lambda-eval-info)
                 (:constructor make-lambda-eval-info
                       (frame-size args-passed entries)))
  frame-size        ;Number of stack locations needed to hold locals.
  args-passed        ;Number of referenced arguments passed to lambda.
  entries        ;A-list mapping entry nodes to stack locations.
  (function nil))    ;A function object corresponding to this lambda.

(defun print-lambda-eval-info (obj str n)
  (declare (ignore n obj))
  (format str "#<Lambda-eval-info>"))

(defstruct (entry-node-info (:print-function print-entry-node-info)
                (:constructor make-entry-node-info
                      (st-top nlx-tag)))
  st-top    ;Stack top when we encounter the entry node.
  nlx-tag)    ;Tag to which to throw to get back entry node's context.

(defun print-entry-node-info (obj str n)
  (declare (ignore n obj))
  (format str "#<Entry-node-info>"))


;;; Some compiler funny functions have definitions, so the interpreter can
;;; call them.  These require special action to coordinate the interpreter,
;;; system call stack, and the environment.  The annotation prepass marks the
;;; references to these as :unused, so the interpreter doesn't try to fetch
;;; function's through these undefined symbols.
;;;
(defconstant undefined-funny-funs
  '(%special-bind %special-unbind %more-arg-context %unknown-values %catch
    %unwind-protect %catch-breakup %unwind-protect-breakup %lexical-exit-breakup
    %continue-unwind %nlx-entry))

;;; Some kinds of functions are only passed as arguments to funny functions,
;;; and are never actually evaluated at run time.
;;;
(defconstant non-closed-function-kinds '(:cleanup :escape))

;;; ANNOTATE-COMPONENT-FOR-EVAL -- Internal.
;;;
;;; This annotates continuations, lambda-vars, and lambdas.  For each
;;; continuation, we cache how its destination uses its value.  This only buys
;;; efficiency when the code executes more than once, but the overhead of this
;;; part of the prepass for code executed only once should be negligible.
;;;
;;; As a special case to aid interpreting local function calls, we sometimes
;;; note the continuation as :unused.  This occurs when there is a local call,
;;; and there is no actual function object to call; we mark the continuation as
;;; :unused since there is nothing to push on the interpreter's stack.
;;; Normally we would see a reference to a function that we would push on the
;;; stack to later pop and apply to the arguments on the stack.  To determine
;;; when we have a local call with no real function object, we look at the node
;;; to see if it is a reference with a destination that is a :local combination
;;; whose function is the reference node's continuation.
;;;
;;; After checking for virtual local calls, we check for funny functions the
;;; compiler refers to for calling to note certain operations.  These functions
;;; are undefined, and if the interpreter tried to reference the function cells
;;; of these symbols, it would get an error.  We mark the continuations
;;; delivering the values of these references as :unused, so the reference
;;; never takes place.
;;;
;;; For each lambda-var, including a lambda's vars and its let's vars, we note
;;; the stack offset used to access and store that variable.  Then we note the
;;; lambda with the total number of variables, so we know how big its stack
;;; frame is.  Also in the lambda's info is the number of its arguments that it
;;; actually references; the interpreter never pushes or pops an unreferenced
;;; argument, so we can't just use LENGTH on LAMBDA-VARS to know how many args
;;; the caller passed.
;;;
;;; For each entry node in a lambda, we associate in the lambda-eval-info the
;;; entry node with a stack offset.  Evaluation code stores the frame pointer
;;; in this slot upon processing the entry node to aid stack cleanup and
;;; correct frame manipulation when processing exit nodes.
;;;
(defun annotate-component-for-eval (component)
  (do-blocks (b component)
    (do-nodes (node cont b)
      (let* ((dest (continuation-dest cont))
         (refp (typep node 'ref))
         (leaf (if refp (ref-leaf node))))
    (setf (continuation-info cont)
          (cond ((and refp dest (typep dest 'basic-combination)
              (eq (basic-combination-kind dest) :local)
              (eq (basic-combination-fun dest) cont))
             :unused)
            ((and leaf (typep leaf 'global-var)
              (eq (global-var-kind leaf) :global-function)
              (member (c::global-var-name leaf) undefined-funny-funs
                  :test #'eq))
             :unused)
            ((and leaf (typep leaf 'clambda)
              (member (functional-kind leaf)
                  non-closed-function-kinds))
             (assert (not (eq (functional-kind leaf) :escape)))
             :unused)
            (t
             (typecase dest
               ;; Change locations in eval.lisp that think :return could
               ;; occur.
               ((or mv-combination creturn exit) :multiple)
               (null :unused)
               (t :single))))))))
  (dolist (lambda (component-lambdas component))
    (let ((locals-count 0)
      (args-passed-count 0))
      (dolist (var (lambda-vars lambda))
    (setf (leaf-info var) locals-count)
    (incf locals-count)
    (when (leaf-refs var) (incf args-passed-count)))
      (dolist (let (lambda-lets lambda))
    (dolist (var (lambda-vars let))
      (setf (leaf-info var) locals-count)
      (incf locals-count)))
      (let ((entries nil))
    (dolist (e (lambda-entries lambda))
      (ecase (process-entry-node-p e)
        (:blow-it-off)
        (:local-lexical-exit
         (push (cons e (make-entry-node-info locals-count nil))
           entries)
         (incf locals-count))
        (:non-local-lexical-exit
         (push (cons e
             (make-entry-node-info locals-count (incf locals-count)))
           entries)
         (incf locals-count))))
    (setf (lambda-info lambda)
          (make-lambda-eval-info locals-count args-passed-count
                     entries))))))

;;; PROCESS-ENTRY-NODE-P -- Internal.
;;;
(defun process-entry-node-p (entry)
  (let ((entry-cleanup (entry-cleanup entry)))
    (dolist (nlx (environment-nlx-info (node-environment entry))
         :local-lexical-exit)
      (let ((cleanup (nlx-info-cleanup nlx)))
    (when (eq entry-cleanup cleanup)
      (ecase (cleanup-kind cleanup)
        ((:block :tagbody)
         (return :non-local-lexical-exit))
        ((:catch :unwind-protect)
         (return :blow-it-off))))))))


;;; Sometime consider annotations to exclude processign of exit nodes when
;;; we want to do a tail-p thing.
;;;


;;;; Defining funny functions for interpreter.

#|
%listify-rest-args %more-arg %verify-argument-count %argument-count-error
%odd-keyword-arguments-error %unknown-keyword-argument-error
|#

(defun %verify-argument-count (supplied-args defined-args)
  (unless (= supplied-args defined-args)
    (error "Wrong argument count, wanted ~D and got ~D."
       defined-args supplied-args)))

;;; Use (SETF SYMBOL-FUNCTION) insetad of DEFUN so that the compiler
;;; doesn't try to compile the hidden %THROW MV-CALL in the throw below as
;;; a local recursive call.
;;;
(setf (symbol-function '%throw)
      #'(lambda (tag &rest args)
      (throw tag (values-list args))))

(defun %more-arg (args index)
  (nth index args))

(defun %listify-rest-args (ptr count)
  (declare (ignore count))
  ptr)

(defun %argument-count-error (args-passed-count)
  (error "Wrong number of arguments passed -- ~S." args-passed-count))

(defun %odd-keyword-arguments-error ()
  (error "Function called with odd number of keyword arguments."))

(defun %unknown-keyword-argument-error (keyword)
  (error "Unknown keyword argument -- ~S." keyword))

(defun %progv (vars vals fun)
  (progv vars vals
    (funcall fun)))

(defun %cleanup-point ())

(defun value-cell-ref (x) (value-cell-ref x))