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;;; -*- 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 slisp-group@cs.cmu.edu.
;;;
(ext:file-comment
"$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/compiler/ir1util.lisp,v 1.57 1992/08/03 12:32:11 ram Exp $")
;;; **********************************************************************
;;;
;;; This file contains random utilities used for manipulating the IR1
;;; representation.
;;;
;;; Written by Rob MacLachlan
;;;
(in-package "C")
(export '(*compiler-notification-function*))
(in-package "EXTENSIONS")
(export '(*error-print-level* *error-print-length* *error-print-lines*
def-source-context *undefined-warning-limit*
*enclosing-source-cutoff*))
(in-package "C")
;;; Node-Enclosing-Cleanup -- Interface
;;; Return the innermost cleanup enclosing Node, or NIL if there is none in
;;; its function. If Node has no cleanup, but is in a let, then we must still
;;; check the environment that the call is in.
(defun node-enclosing-cleanup (node)
(declare (type node node))
(do ((lexenv (node-lexenv node)
(lambda-call-lexenv (lexenv-lambda lexenv))))
((null lexenv) nil)
(let ((cup (lexenv-cleanup lexenv)))
(when cup (return cup)))))
;;; Insert-Cleanup-Code -- Interface
;;;
;;; Convert the Form in a block inserted between Block1 and Block2 as an
;;; implicit MV-Prog1. The inserted block is returned. Node is used for IR1
;;; context when converting the form. Note that the block is not assigned a
;;; number, and is linked into the DFO at the beginning. We indicate that we
;;; have trashed the DFO by setting Component-Reanalyze. If Cleanup is
;;; supplied, then convert with that cleanup.
(defun insert-cleanup-code (block1 block2 node form &optional cleanup)
(declare (type cblock block1 block2) (type node node)
(type (or cleanup null) cleanup))
(setf (component-reanalyze (block-component block1)) t)
(with-ir1-environment node
(let* ((start (make-continuation))
(block (continuation-starts-block start))
(cont (make-continuation))
(*lexical-environment*
(if cleanup
(make-lexenv :cleanup cleanup)
*lexical-environment*)))
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(change-block-successor block1 block2 block)
(link-blocks block block2)
(ir1-convert start cont form)
(setf (block-last block) (continuation-use cont))
block)))
;;;; Continuation use hacking:
;;; Find-Uses -- Interface
;;;
;;; Return a list of all the nodes which use Cont.
;;;
(proclaim '(function find-uses (continuation) list))
(defun find-uses (cont)
(ecase (continuation-kind cont)
((:block-start :deleted-block-start)
(block-start-uses (continuation-block cont)))
(:inside-block (list (continuation-use cont)))
(:unused nil)))
;;; Delete-Continuation-Use -- Interface
;;;
;;; Update continuation use information so that Node is no longer a use of
;;; its Cont. If the old continuation doesn't start its block, then we don't
;;; update the Block-Start-Uses, since it will be deleted when we are done.
;;;
;;; Note: if you call this function, you may have to do a
;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something has
;;; changed.
;;;
(proclaim '(function delete-continuation-use (node) void))
(defun delete-continuation-use (node)
(let* ((cont (node-cont node))
(block (continuation-block cont)))
(ecase (continuation-kind cont)
(:deleted)
((:block-start :deleted-block-start)
(let ((uses (delete node (block-start-uses block))))
(setf (block-start-uses block) uses)
(setf (continuation-use cont)
(if (cdr uses) nil (car uses)))))
(:inside-block
(setf (continuation-kind cont) :unused)
(setf (continuation-block cont) nil)
(setf (continuation-use cont) nil)
(setf (continuation-next cont) nil)))
(setf (node-cont node) nil)))
;;; Add-Continuation-Use -- Interface
;;;
;;; Update continuation use information so that Node uses Cont. If Cont is
;;; :Unused, then we set its block to Node's Node-Block (which must be set.)
;;;
;;; Note: if you call this function, you may have to do a
;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something has
;;; changed.
;;;
(proclaim '(function add-continuation-use (node continuation) void))
(defun add-continuation-use (node cont)
(assert (not (node-cont node)))
(let ((block (continuation-block cont)))
(ecase (continuation-kind cont)
(:deleted)
(:unused
(assert (not block))
(let ((block (node-block node)))
(assert block)
(setf (continuation-block cont) block))
(setf (continuation-kind cont) :inside-block)
(setf (continuation-use cont) node))
((:block-start :deleted-block-start)
(let ((uses (cons node (block-start-uses block))))
(setf (block-start-uses block) uses)
(setf (continuation-use cont)
(if (cdr uses) nil (car uses)))))))
(setf (node-cont node) cont))
;;; Immediately-Used-P -- Interface
;;;
;;; Return true if Cont is the Node-Cont for Node and Cont is transferred to
;;; immediately after the evaluation of Node.
;;;
(defun immediately-used-p (cont node)
(declare (type continuation cont) (type node node))
(and (eq (node-cont node) cont)
(not (eq (continuation-kind cont) :deleted))
(let ((cblock (continuation-block cont))
(nblock (node-block node)))
(or (eq cblock nblock)
(let ((succ (block-succ nblock)))
(and (= (length succ) 1)
(eq (first succ) cblock)))))))
;;;; Continuation substitution:
;;; Substitute-Continuation -- Interface
;;;
;;; In Old's Dest, replace Old with New. New's Dest must initially be NIL.
;;; When we are done, we call Flush-Dest on Old to clear its Dest and to note
;;; potential optimization opportunities.
;;;
(defun substitute-continuation (new old)
(declare (type continuation old new))
(assert (not (continuation-dest new)))
(let ((dest (continuation-dest old)))
(etypecase dest
((or ref bind))
(cif (setf (if-test dest) new))
(cset (setf (set-value dest) new))
(creturn (setf (return-result dest) new))
(exit (setf (exit-value dest) new))
(basic-combination
(if (eq old (basic-combination-fun dest))
(setf (basic-combination-fun dest) new)
(setf (basic-combination-args dest)
(nsubst new old (basic-combination-args dest))))))
(flush-dest old)
(setf (continuation-dest new) dest))
(undefined-value))
;;; Ensure-Block-Start -- Interface
;;;
;;; Ensure that Cont is the start of a block (or deleted) so that the use
;;; set can be freely manipulated.
;;; -- If the continuation is :Unused or is :Inside-Block and the Cont of Last
;;; in its block, then we make it the start of a new deleted block.
;;; -- If the continuation is :Inside-Block inside a block, then we split the
;;; block using Node-Ends-Block, which makes the continuation be a
;;; :Block-Start.
;;;
(defun ensure-block-start (cont)
(declare (type continuation cont))
(let ((kind (continuation-kind cont)))
(ecase kind
((:deleted :block-start :deleted-block-start))
((:unused :inside-block)
(let ((block (continuation-block cont)))
(cond ((or (eq kind :unused)
(eq (node-cont (block-last block)) cont))
(setf (continuation-block cont)
(make-block-key :start cont :component nil
:start-uses (find-uses cont)))
(setf (continuation-kind cont) :deleted-block-start))
(t
(node-ends-block (continuation-use cont))))))))
(undefined-value))
;;; Substitute-Continuation-Uses -- Interface
;;;
;;; Replace all uses of Old with uses of New, where New has an arbitary
;;; number of uses. If New will end up with more than one use, then we must
;;; arrange for it to start a block if it doesn't already.
;;;
(defun substitute-continuation-uses (new old)
(declare (type continuation old new))
(unless (and (eq (continuation-kind new) :unused)
(eq (continuation-kind old) :inside-block))
(ensure-block-start new))
(do-uses (node old)
(delete-continuation-use node)
(add-continuation-use node new))
(reoptimize-continuation new)
(undefined-value))
;;;; Misc shortand functions:
;;; NODE-HOME-LAMBDA -- Interface
;;;
;;; Return the home (i.e. enclosing non-let) lambda for Node. Since the
;;; LEXENV-LAMBDA may be deleted, we must chain up the LAMBDA-CALL-LEXENV
;;; thread until we find a lambda that isn't deleted, and then return its home.
;;;
(declaim (maybe-inline node-home-lambda))
(defun node-home-lambda (node)
(declare (type node node))
(do ((fun (lexenv-lambda (node-lexenv node))
(lexenv-lambda (lambda-call-lexenv fun))))
((not (eq (functional-kind fun) :deleted))
(lambda-home fun))
(when (eq (lambda-home fun) fun)
(return fun))))
;;; NODE-xxx -- Interface
(declaim (inline node-block node-tlf-number))
(declaim (maybe-inline node-environment))
(defun node-block (node)
(declare (type node node))
(the cblock (continuation-block (node-prev node))))
;;;
(defun node-environment (node)
(declare (type node node) (inline node-home-lambda))
(the environment (lambda-environment (node-home-lambda node))))
;;; BLOCK-xxx-CLEANUP -- Interface
;;;
;;; Return the enclosing cleanup for environment of the first or last node
;;; in Block.
;;;
(defun block-start-cleanup (block)
(declare (type cblock block))
(node-enclosing-cleanup (continuation-next (block-start block))))
;;;
(defun block-end-cleanup (block)
(declare (type cblock block))
(node-enclosing-cleanup (block-last block)))
;;; BLOCK-HOME-LAMBDA -- Interface
;;;
;;; Return the non-let lambda that holds Block's code.
;;;
(defun block-home-lambda (block)
(declare (type cblock block) (inline node-home-lambda))
(node-home-lambda (block-last block)))
;;; BLOCK-ENVIRONMENT -- Interface
;;;
;;; Return the IR1 environment for Block.
;;;
(defun block-environment (block)
(declare (type cblock block) (inline node-home-lambda))
(lambda-environment (node-home-lambda (block-last block))))
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;;; SOURCE-PATH-TLF-NUMBER -- Interface
;;;
;;; Return the Top Level Form number of path, i.e. the ordinal number of
;;; its orignal source's top-level form in its compilation unit.
;;;
(defun source-path-tlf-number (path)
(declare (list path))
(car (last path)))
;;; SOURCE-PATH-ORIGINAL-SOURCE -- Interface
;;;
;;; Return the (reversed) list for the path in the orignal source (with the
;;; TLF number last.)
;;;
(defun source-path-original-source (path)
(declare (list path))
(cddr (member 'original-source-start path)))
;;; SOURCE-PATH-FORM-NUMBER -- Interface
;;;
;;; Return the Form Number of Path's orignal source inside the Top Level
;;; Form that contains it. This is determined by the order that we walk the
;;; subforms of the top level source form.
;;;
(defun source-path-form-number (path)
(declare (list path))
(cadr (member 'original-source-start path)))
;;; SOURCE-PATH-FORMS -- Interface
;;;
;;; Return a list of all the enclosing forms not in the original source that
;;; converted to get to this form, with the immediate source for node at the
;;; start of the list.
;;;
(defun source-path-forms (path)
(subseq path 0 (position 'original-source-start path)))
;;; NODE-SOURCE-FORM -- Interface
;;;
;;; Return the innermost source form for Node.
;;;
(defun node-source-form (node)
(declare (type node node))
(let* ((path (node-source-path node))
(forms (source-path-forms path)))
(if forms
(first forms)
(values (find-original-source path)))))
;;; CONTINUATION-SOURCE-FORM -- Interface
;;;
;;; Return NODE-SOURCE-FORM, T if continuation has a single use, otherwise
;;; NIL, NIL.
;;;
(defun continuation-source (cont)
(let ((use (continuation-use cont)))
(if use
(values (node-source-form use) t)
(values nil nil))))
;;; MAKE-LEXENV -- Interface
;;;
;;; Return a new LEXENV just like Default except for the specified slot
;;; values. Values for the alist slots are NCONC'ed to the beginning of the
;;; current value, rather than replacing it entirely.
;;;
(defun make-lexenv (&key (default *lexical-environment*)
functions variables blocks tags type-restrictions
(lambda (lexenv-lambda default))
(cleanup (lexenv-cleanup default))
(cookie (lexenv-cookie default))
(interface-cookie (lexenv-interface-cookie default)))
(macrolet ((frob (var slot)
`(let ((old (,slot default)))
(if ,var
(nconc ,var old)
old))))
(internal-make-lexenv
(frob functions lexenv-functions)
(frob variables lexenv-variables)
(frob blocks lexenv-blocks)
(frob tags lexenv-tags)
(frob type-restrictions lexenv-type-restrictions)
(frob inlines lexenv-inlines)
lambda cleanup cookie interface-cookie
(frob options lexenv-options))))
;;; MAKE-INTERFACE-COOKIE -- Interface
;;;
;;; Return a cookie that defaults any unsupplied optimize qualities in the
;;; Interface-Cookie with the corresponding ones from the Cookie.
;;;
(defun make-interface-cookie (lexenv)
(declare (type lexenv lexenv))
(let ((icookie (lexenv-interface-cookie lexenv))
(cookie (lexenv-cookie lexenv)))
(make-cookie
:speed (or (cookie-speed icookie) (cookie-speed cookie))
:space (or (cookie-space icookie) (cookie-space cookie))
:safety (or (cookie-safety icookie) (cookie-safety cookie))
:cspeed (or (cookie-cspeed icookie) (cookie-cspeed cookie))
:brevity (or (cookie-brevity icookie) (cookie-brevity cookie))
:debug (or (cookie-debug icookie) (cookie-debug cookie)))))
;;; Link-Blocks -- Interface
;;; Join Block1 and Block2.
(declare (type cblock block1 block2))
(assert (not (member block2 (block-succ block1))))
(push block2 (block-succ block1))
(push block1 (block-pred block2))
(undefined-value))
;;; UNLINK-BLOCKS -- Interface
;;;
;;; Like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If this leaves a
;;; successor with a single predecessor that ends in an IF, then set
;;; BLOCK-TEST-MODIFIED so that any test constraint will now be able to be
;;; propagated to the successor.
(declare (type cblock block1 block2))
(assert (member block2 (block-succ block1)))
(setf (block-succ block1)
(delete block2 (block-succ block1)))
(let ((new-pred (delete block1 (block-pred block2))))
(setf (block-pred block2) new-pred)
(when (and new-pred (null (rest new-pred)))
(let ((pred-block (first new-pred)))
(when (if-p (block-last pred-block))
(setf (block-test-modified pred-block) t)))))
(undefined-value))
;;; Change-Block-Successor -- Internal
;;;
;;; Swing the succ/pred link between Block and Old to be between Block and
;;; New. If Block ends in an IF, then we have to fix up the
;;; consequent/alternative blocks to point to New. We also set
;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to the new
;;; successor.
;;;
(defun change-block-successor (block old new)
(declare (type cblock new old block))
(unlink-blocks block old)
(setf (component-reanalyze (block-component block)) t)
(unless (member new (block-succ block))
(link-blocks block new))
(let ((last (block-last block)))
(when (if-p last)
(setf (block-test-modified block) t)
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(macrolet ((frob (slot)
`(when (eq (,slot last) old)
(setf (,slot last) new))))
(frob if-consequent)
(frob if-alternative))))
(undefined-value))
;;; Remove-From-DFO -- Interface
;;;
;;; Unlink a block from the next/prev chain. We also null out the
;;; Component.
;;;
(proclaim '(function remove-from-dfo (cblock) void))
(defun remove-from-dfo (block)
(let ((next (block-next block))
(prev (block-prev block)))
(setf (block-component block) nil)
(setf (block-next prev) next)
(setf (block-prev next) prev)))
;;; Add-To-DFO -- Interface
;;;
;;; Add Block to the next/prev chain following After. We also set the
;;; Component to be the same as for After.
;;;
(defun add-to-dfo (block after)
(declare (type cblock block after))
(let ((next (block-next after))
(comp (block-component after)))
(assert (not (eq (component-kind comp) :deleted)))
(setf (block-component block) comp)
(setf (block-next after) block)
(setf (block-prev block) after)
(setf (block-next block) next)
(setf (block-prev next) block))
(undefined-value))
;;; Clear-Flags -- Interface
;;;
;;; Set the Flag for all the blocks in Component to NIL, except for the head
;;; and tail which are set to T.
;;;
(proclaim '(function clear-flags (component) void))
(defun clear-flags (component)
(let ((head (component-head component))
(tail (component-tail component)))
(setf (block-flag head) t)
(setf (block-flag tail) t)
(do-blocks (block component)
(setf (block-flag block) nil))))
;;; Make-Empty-Component -- Interface
;;;
;;; Make a component with no blocks in it. The Block-Flag is initially true
;;; in the head and tail blocks.
;;;
(proclaim '(function make-empty-component () component))
(defun make-empty-component ()
(let* ((head (make-block-key :start nil :component nil))
(tail (make-block-key :start nil :component nil))
(res (make-component :head head :tail tail)))
(setf (block-flag head) t)
(setf (block-flag tail) t)
(setf (block-component head) res)
(setf (block-component tail) res)
(setf (block-next head) tail)
(setf (block-prev tail) head)
res))
;;; Node-Ends-Block -- Interface
;;;
;;; Makes Node the Last node in its block, splitting the block if necessary.
;;; The new block is added to the DFO immediately following Node's block.
;;;
(defun node-ends-block (node)
(declare (type node node))
(let* ((block (node-block node))
(start (node-cont node))
(last (block-last block))
(last-cont (node-cont last)))
(unless (eq last node)
(assert (and (eq (continuation-kind start) :inside-block)
(not (block-delete-p block))))
(let* ((succ (block-succ block))
(new-block
(make-block-key :start start
:component (block-component block)
:start-uses (list (continuation-use start))
:succ succ :last last)))
(setf (continuation-kind start) :block-start)
(dolist (b succ)
(setf (block-pred b)
(cons new-block (remove block (block-pred b)))))
(setf (block-succ block) ())
(setf (block-last block) node)
(link-blocks block new-block)
(add-to-dfo new-block block)
(setf (component-reanalyze (block-component block)) t)
(do ((cont start (node-cont (continuation-next cont))))
((eq cont last-cont)
(when (eq (continuation-kind last-cont) :inside-block)
(setf (continuation-block last-cont) new-block)))
(setf (continuation-block cont) new-block))
(setf (block-type-asserted block) t)
(setf (block-test-modified block) t))))
(undefined-value))
;;;; Deleting stuff:
;;; Delete-Lambda-Var -- Internal
;;;
;;; Deal with deleting the last (read) reference to a lambda-var. We
;;; iterate over all local calls flushing the corresponding argument, allowing
;;; the computation of the argument to be deleted. We also mark the let for
;;; reoptimization, since it may be that we have deleted the last variable.
;;;
;;; The lambda-var may still have some sets, but this doesn't cause too much
;;; difficulty, since we can efficiently implement write-only variables. We
;;; iterate over the sets, marking their blocks for dead code flushing, since
;;; we can delete sets whose value is unused.
;;;
(defun delete-lambda-var (leaf)
(declare (type lambda-var leaf))
(let* ((fun (lambda-var-home leaf))
(n (position leaf (lambda-vars fun))))
(dolist (ref (leaf-refs fun))
(let* ((cont (node-cont ref))
(dest (continuation-dest cont)))
(when (and (combination-p dest)
(eq (basic-combination-fun dest) cont)
(eq (basic-combination-kind dest) :local))
(let* ((args (basic-combination-args dest))
(arg (elt args n)))
(reoptimize-continuation arg)
(flush-dest arg)
(setf (elt args n) nil))))))
(dolist (set (lambda-var-sets leaf))
(setf (block-flush-p (node-block set)) t))
(undefined-value))
;;; REOPTIMIZE-LAMBDA-VAR -- Internal
;;;
;;; Note that something interesting has happened to Var. We only deal with
;;; LET variables, marking the corresponding initial value arg as needing to be
;;; reoptimized.
;;;
(defun reoptimize-lambda-var (var)
(declare (type lambda-var var))
(let ((fun (lambda-var-home var)))
(when (and (eq (functional-kind fun) :let)
(leaf-refs var))
(reoptimize-continuation
(elt (basic-combination-args
(continuation-dest
(node-cont
(first (leaf-refs fun)))))
(position var (lambda-vars fun))))))
(undefined-value))
;;; DELETE-FUNCTIONAL -- Interface
;;;
;;; This function deletes functions that have no references. This need only
;;; be called on functions that never had any references, since otherwise
;;; DELETE-REF will handle the deletion.
;;;
(defun delete-functional (fun)
(assert (and (null (leaf-refs fun))
(not (functional-entry-function fun))))
(etypecase fun
(optional-dispatch (delete-optional-dispatch fun))
(clambda (delete-lambda fun)))
(undefined-value))
;;; MAYBE-REMOVE-FREE-FUNCTION -- Interface
;;;
;;; This function is called when we let convert a function or blow away an
;;; XEP, or otherwise do something that should prevent any new references to
;;; Fun (or its optional-dispatch) from being created.
;;;
(defun maybe-remove-free-function (fun)
(declare (type functional fun))
(let* ((fun (etypecase fun
(clambda (or (lambda-optional-dispatch fun) fun))
(optional-dispatch fun)))
(entry (gethash (leaf-name fun) *free-functions*)))
(when (eq entry fun)
(remhash (leaf-name fun) *free-functions*)))
(undefined-value))
;;; Delete-Lambda -- Internal
;;;
;;; Deal with deleting the last reference to a lambda. Since there is only
;;; one way into a lambda, deleting the last reference to a lambda ensures that
;;; there is no way to reach any of the code in it. So we just set the
;;; Functional-Kind for Fun and its Lets to :Deleted, causing IR1 optimization
;;; to delete blocks in that lambda.
;;;
;;; If the function isn't a Let, we unlink the function head and tail from
;;; the component head and tail to indicate that the code is unreachable. We
;;; also delete the function from Component-Lambdas (it won't be there before
;;; local call analysis, but no matter.) If the lambda was never referenced,
;;; we give a note.
;;;
;;; If the lambda is an XEP, then we null out the Entry-Function in its
;;; Entry-Function so that people will know that it is not an entry point
;;; anymore.
;;;
(defun delete-lambda (leaf)
(declare (type clambda leaf))
(let ((kind (functional-kind leaf))
(bind (lambda-bind leaf)))
(assert (not (member kind '(:deleted :optional :top-level))))
(setf (functional-kind leaf) :deleted)
(setf (lambda-bind leaf) nil)
(setf (lambda-bind let) nil)
(if (member kind '(:let :mv-let :assignment))
(let ((home (lambda-home leaf)))
(setf (lambda-lets home) (delete leaf (lambda-lets home))))
(let* ((bind-block (node-block bind))
(component (block-component bind-block))
(return (lambda-return leaf)))
(assert (null (leaf-refs leaf)))
(unless (leaf-ever-used leaf)
(let ((*compiler-error-context* bind))
(compiler-note "Deleting unused function~:[.~;~:*~% ~S~]"
(leaf-name leaf))))
(unlink-blocks (component-head component) bind-block)
(when return
(unlink-blocks (node-block return) (component-tail component)))
(setf (component-reanalyze component) t)
(let ((tails (lambda-tail-set leaf)))
(setf (tail-set-functions tails)
(delete leaf (tail-set-functions tails)))
(setf (lambda-tail-set leaf) nil))
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(setf (component-lambdas component)
(delete leaf (component-lambdas component)))))
(when (eq kind :external)
(let ((fun (functional-entry-function leaf)))
(setf (functional-entry-function fun) nil)
(when (optional-dispatch-p fun)
(delete-optional-dispatch fun)))))
(undefined-value))
;;; Delete-Optional-Dispatch -- Internal
;;;
;;; Deal with deleting the last reference to an Optional-Dispatch. We have
;;; to be a bit more careful than with lambdas, since Delete-Ref is used both
;;; before and after local call analysis. Afterward, all references to
;;; still-existing optional-dispatches have been moved to the XEP, leaving it
;;; with no references at all. So we look at the XEP to see if an
;;; optional-dispatch is still really being used. But before local call
;;; analysis, there are no XEPs, and all references are direct.
;;;
;;; When we do delete the optional-dispatch, we grovel all of its
;;; entry-points, making them be normal lambdas, and then deleting the ones
;;; with no references. This deletes any e-p lambdas that were either never
;;; referenced, or couldn't be deleted when the last deference was deleted (due
;;; to their :Optional kind.)
;;;
;;; Note that the last optional ep may alias the main entry, so when we process
;;; the main entry, its kind may have been changed to NIL or even converted to
;;; a let.
;;;
(defun delete-optional-dispatch (leaf)
(declare (type optional-dispatch leaf))
(maybe-remove-free-function leaf)
(let ((entry (functional-entry-function leaf)))
(unless (and entry (leaf-refs entry))
(assert (or (not entry) (eq (functional-kind entry) :deleted)))
(setf (functional-kind leaf) :deleted)
(flet ((frob (fun)
(unless (eq (functional-kind fun) :deleted)
(assert (eq (functional-kind fun) :optional))
(setf (functional-kind fun) nil)
(let ((refs (leaf-refs fun)))
(cond ((null refs)
(delete-lambda fun))
((null (rest refs))
(or (maybe-let-convert fun)
(maybe-convert-to-assignment fun)))
(t
(maybe-convert-to-assignment fun)))))))
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(dolist (ep (optional-dispatch-entry-points leaf))
(frob ep))
(when (optional-dispatch-more-entry leaf)
(frob (optional-dispatch-more-entry leaf)))
(let ((main (optional-dispatch-main-entry leaf)))
(when (eq (functional-kind main) :optional)
(frob main))))))
(undefined-value))
;;; Delete-Ref -- Interface
;;;
;;; Do stuff to delete the semantic attachments of a Ref node. When this
;;; leaves zero or one reference, we do a type dispatch off of the leaf to
;;; determine if a special action is appropriate.
;;;
(defun delete-ref (ref)
(declare (type ref ref))
(let* ((leaf (ref-leaf ref))
(refs (delete ref (leaf-refs leaf))))
(setf (leaf-refs leaf) refs)
(cond ((null refs)
(typecase leaf
(lambda-var (delete-lambda-var leaf))
(clambda
(ecase (functional-kind leaf)
((nil :let :mv-let :assignment :escape :cleanup)
(assert (not (functional-entry-function leaf)))
(delete-lambda leaf))
(delete-lambda leaf))
((:deleted :optional))))
(optional-dispatch
(unless (eq (functional-kind leaf) :deleted)
(delete-optional-dispatch leaf)))))
((null (rest refs))
(typecase leaf
(clambda (or (maybe-let-convert leaf)
(maybe-convert-to-assignment leaf)))
(lambda-var (reoptimize-lambda-var leaf))))
(t
(typecase leaf
(clambda (maybe-convert-to-assignment leaf))))))
(undefined-value))
;;; Delete-Return -- Interface
;;;
;;; Do stuff to indicate that the return node Node is being deleted. We set
;;; the RETURN to NIL.
;;;
(defun delete-return (node)
(declare (type creturn node))
(let ((fun (return-lambda node)))
(assert (lambda-return fun))
(setf (lambda-return fun) nil))
(undefined-value))
;;; NOTE-UNREFERENCED-VARS -- Interface
;;;
;;; If any of the Vars in fun were never referenced and was not declared
;;; IGNORE, then complain.
;;;
(defun note-unreferenced-vars (fun)
(declare (type clambda fun))
(dolist (var (lambda-vars fun))
(unless (or (leaf-ever-used var)
(lambda-var-ignorep var))
(let ((*compiler-error-context* (lambda-bind fun)))
(unless (policy *compiler-error-context* (= brevity 3))
(compiler-warning "Variable ~S defined but never used."
(leaf-name var)))
(setf (leaf-ever-used var) t))))
(undefined-value))
;;; Flush-Dest -- Interface
;;;
;;; This function is called by people who delete nodes; it provides a way to
;;; indicate that the value of a continuation is no longer used. We null out
;;; the Continuation-Dest, set Flush-P in the blocks containing uses of Cont
;;; and set Component-Reoptimize. If the Prev of the use is deleted, then we
;;; blow off reoptimization.
;;;
;;; If the continuation is :Deleted, then we don't do anything, since all
;;; semantics have already been flushed. :Deleted-Block-Start start
;;; continuations are treated just like :Block-Start; it is possible that the
;;; continuation may be given a new dest (e.g. by SUBSTITUTE-CONTINUATION), so
;;; we don't want to delete it.
;;;
(defun flush-dest (cont)
(declare (type continuation cont))
(unless (eq (continuation-kind cont) :deleted)
(assert (continuation-dest cont))
(setf (continuation-dest cont) nil)
(do-uses (use cont)
(let ((prev (node-prev use)))
(unless (eq (continuation-kind prev) :deleted)
(let ((block (continuation-block prev)))
(setf (component-reoptimize (block-component block)) t)
(setf (block-attributep (block-flags block) flush-p type-asserted)
t))))))
(setf (continuation-%type-check cont) nil)
(undefined-value))
;;; MARK-FOR-DELETION -- Internal
;;;
;;; Do a graph walk backward from Block, marking all predecessor blocks with
;;; the DELETE-P flag.
;;;
(defun mark-for-deletion (block)
(declare (type cblock block))
(unless (block-delete-p block)
(setf (block-delete-p block) t)
(setf (component-reanalyze (block-component block)) t)
(dolist (pred (block-pred block))
(mark-for-deletion pred)))
(undefined-value))
;;; DELETE-CONTINUATION -- Interface
;;;
;;; Delete Cont, eliminating both control and value semantics. We set
;;; FLUSH-P and COMPONENT-REOPTIMIZE similarly to in FLUSH-DEST. Here we must
;;; get the component from the use block, since the continuation may be a
;;; :DELETED-BLOCK-START.
;;;
;;; If Cont has DEST, then it must be the case that the DEST is unreachable,
;;; since we can't compute the value desired. In this case, we call
;;; MARK-FOR-DELETION to cause the DEST block and its predecessors to tell
;;; people to ignore them, and to cause them to be deleted eventually.
;;;
(defun delete-continuation (cont)
(declare (type continuation cont))
(assert (not (eq (continuation-kind cont) :deleted)))
(do-uses (use cont)
(let ((prev (node-prev use)))
(unless (eq (continuation-kind prev) :deleted)
(let ((block (continuation-block prev)))
(setf (block-attributep (block-flags block) flush-p type-asserted) t)
(setf (component-reoptimize (block-component block)) t)))))
(let ((dest (continuation-dest cont)))
(when dest
(let ((prev (node-prev dest)))
(when (and prev
(not (eq (continuation-kind prev) :deleted)))
(let ((block (continuation-block prev)))
(unless (block-delete-p block)
(mark-for-deletion block)))))))
(setf (continuation-kind cont) :deleted)
(setf (continuation-dest cont) nil)
(setf (continuation-next cont) nil)
(setf (continuation-asserted-type cont) *empty-type*)
(setf (continuation-%derived-type cont) *empty-type*)
(setf (continuation-use cont) nil)
(setf (continuation-block cont) nil)
(setf (continuation-reoptimize cont) nil)
(setf (continuation-%type-check cont) nil)
(setf (continuation-info cont) nil)
(undefined-value))
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(defvar *deletion-ignored-objects* '(t nil))
;;; PRESENT-IN-FORM -- Internal
;;;
;;; Return true if we can find Obj in Form, NIL otherwise. We bound our
;;; recursion so that we don't get lost in circular structures. We ignore the
;;; car of forms if they are a symbol (to prevent confusing function
;;; referencess with variables), and we also ignore anything inside ' or #'.
;;;
(defun present-in-form (obj form depth)
(declare (type (integer 0 20) depth))
(cond ((= depth 20) nil)
((eq obj form) t)
((atom form) nil)
(t
(let ((first (car form))
(depth (1+ depth)))
(if (member first '(quote function))
nil
(or (and (not (symbolp first))
(present-in-form obj first depth))
(do ((l (cdr form) (cdr l))
(n 0 (1+ n)))
((or (atom l) (> n 100))
nil)
(declare (fixnum n))
(when (present-in-form obj (car l) depth)
(return t)))))))))
;;; NOTE-BLOCK-DELETION -- Internal
;;;
;;; This function is called on a block immediately before we delete it. We
;;; check to see if any of the code about to die appeared in the original
;;; source, and emit a note if so.
;;;
;;; If the block was in a lambda is now deleted, then we ignore the whole
;;; block, since this case is picked off in DELETE-LAMBDA. We also ignore the
;;; deletion of CRETURN nodes, since it is somewhat reasonable for a function
;;; to not return, and there is a different note for that case anyway.
;;;
;;; If the actual source is an atom, then we use a bunch of heuristics to
;;; guess whether this reference really appeared in the original source:
;;; -- If a symbol, it must be interned and not a keyword.
;;; -- It must not be an easily introduced constant (T or NIL, a fixnum or a
;;; character.)
;;; -- The atom must be "present" in the original source form, and present in
;;; all intervening actual source forms.
;;;
(defun note-block-deletion (block)
(let ((home (block-home-lambda block)))
(unless (eq (functional-kind home) :deleted)
(do-nodes (node cont block)
(let* ((path (node-source-path node))
(first (first path)))
(when (or (eq first 'original-source-start)
(and (atom first)
(or (not (symbolp first))
(let ((pkg (symbol-package first)))
(and pkg
(not (eq pkg (symbol-package :end))))))
(not (member first *deletion-ignored-objects*))
(not (typep first '(or fixnum character)))
(every #'(lambda (x)
(present-in-form first x 0))
(source-path-forms path))
(present-in-form first (find-original-source path)
0)))
(unless (return-p node)
(let ((*compiler-error-context* node))
(compiler-note "Deleting unreachable code.")))
(return))))))
(undefined-value))
;;; Delete-Block -- Interface
;;;
;;; This function does what is necessary to eliminate the code in it from
;;; the IR1 representation. This involves unlinking it from its predecessors
;;; and successors and deleting various node-specific semantic information.
;;;
;;; We mark the Start as has having no next and remove the last node from
;;; its Cont's uses. We also flush the DEST for all continuations whose values
;;; are received by nodes in the block.
;;;
(defun delete-block (block)
(declare (type cblock block))
(assert (block-component block) () "Block is already deleted.")
(note-block-deletion block)
(setf (block-delete-p block) t)
(let* ((last (block-last block))
(cont (node-cont last)))
(delete-continuation-use last)
(if (eq (continuation-kind cont) :unused)
(delete-continuation cont)
(reoptimize-continuation cont)))
(dolist (b (block-pred block))
(unlink-blocks b block))
(dolist (b (block-succ block))
(unlink-blocks block b))
(do-nodes (node cont block)
(typecase node
(ref (delete-ref node))
(cif
(flush-dest (if-test node)))
;;
;; The next two cases serve to maintain the invariant that a LET always
;; has a well-formed COMBINATION, REF and BIND. We delete the lambda
;; whenever we delete any of these, but we must be careful that this LET
;; has not already been partially deleted.
(when (and (eq (basic-combination-kind node) :local)
;; Guards COMBINATION-LAMBDA agains the REF being deleted.
(continuation-use (basic-combination-fun node)))
(let ((fun (combination-lambda node)))
;; If our REF was the 2'nd to last ref, and has been deleted, then
;; Fun may be a LET for some other combination.
(when (and (member (functional-kind fun) '(:let :mv-let))
(eq (let-combination fun) node))
(delete-lambda fun))))
(flush-dest (basic-combination-fun node))
(dolist (arg (basic-combination-args node))
(when arg (flush-dest arg))))
(bind
(let ((lambda (bind-lambda node)))
(unless (eq (functional-kind lambda) :deleted)
(assert (member (functional-kind lambda)
'(:let :mv-let :assignment)))
(delete-lambda lambda))))
(let ((value (exit-value node))
(entry (exit-entry node)))
(flush-dest value))
(when entry
(setf (entry-exits entry)
(delete node (entry-exits entry))))))
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(creturn
(flush-dest (return-result node))
(delete-return node))
(cset
(flush-dest (set-value node))
(let ((var (set-var node)))
(setf (basic-var-sets var)
(delete node (basic-var-sets var))))))
(delete-continuation (node-prev node)))
(remove-from-dfo block)
(undefined-value))
;;; Unlink-Node -- Interface
;;;
;;; Delete a node from a block, deleting the block if there are no nodes
;;; left. We remove the node from the uses of its CONT, but we don't deal with
;;; cleaning up any type-specific semantic attachments. If the CONT is :UNUSED
;;; after deleting this use, then we delete CONT. (Note :UNUSED is not the
;;; same as no uses. A continuation will only become :UNUSED if it was
;;; :INSIDE-BLOCK before.)
;;;
;;; If the node is the last node, there must be exactly one successor. We
;;; link all of our precedessors to the successor and unlink the block. In
;;; this case, we return T, otherwise NIL. If no nodes are left, and the block
;;; is a successor of itself, then we replace the only node with a degenerate
;;; exit node. This provides a way to represent the bodyless infinite loop,
;;; given the prohibition on empty blocks in IR1.
;;;
(defun unlink-node (node)
(declare (type node node))
(let* ((cont (node-cont node))
(next (continuation-next cont))
(prev (node-prev node))
(block (continuation-block prev))
(prev-kind (continuation-kind prev))
(last (block-last block)))
(unless (eq (continuation-kind cont) :deleted)
(delete-continuation-use node)
(when (eq (continuation-kind cont) :unused)
(assert (not (continuation-dest cont)))
(delete-continuation cont)))
(setf (block-type-asserted block) t)
(setf (block-test-modified block) t)
(cond ((or (eq prev-kind :inside-block)
(and (eq prev-kind :block-start)
(not (eq node last))))
(cond ((eq node last)
(setf (block-last block) (continuation-use prev))
(setf (continuation-next prev) nil))
(t
(setf (continuation-next prev) next)
(setf (node-prev next) prev)))
(setf (node-prev node) nil)
nil)
(t
(assert (eq prev-kind :block-start))
(assert (eq node last))
(let* ((succ (block-succ block))
(next (first succ)))
(assert (and succ (null (cdr succ))))
(cond
((member block succ)
(with-ir1-environment node
(let ((exit (make-exit))
(dummy (make-continuation)))
(setf (continuation-next prev) nil)
(prev-link exit prev)
(add-continuation-use exit dummy)
(setf (block-last block) exit)))
(setf (node-prev node) nil)
nil)
(t
(assert (eq (block-start-cleanup block)
(block-end-cleanup block)))
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(unlink-blocks block next)
(dolist (pred (block-pred block))
(change-block-successor pred block next))
(remove-from-dfo block)
(cond ((continuation-dest prev)
(setf (continuation-next prev) nil)
(setf (continuation-kind prev) :deleted-block-start))
(t
(delete-continuation prev)))
(setf (node-prev node) nil)
t)))))))
;;; NODE-DELETED -- Interface
;;;
;;; Return true if NODE has been deleted, false if it is still a valid part
;;; of IR1.
;;;
(defun node-deleted (node)
(declare (type node node))
(let ((prev (node-prev node)))
(not (and prev
(not (eq (continuation-kind prev) :deleted))
(let ((block (continuation-block prev)))
(and (block-component block)
(not (block-delete-p block))))))))
;;; DELETE-COMPONENT -- Interface
;;;
;;; Delete all the blocks and functions in Component. We scan first marking
;;; the blocks as delete-p to prevent weird stuff from being triggered by
;;; deletion.
;;;
(defun delete-component (component)
(declare (type component component))
(assert (null (component-new-functions component)))
(setf (component-kind component) :deleted)
(do-blocks (block component)
(setf (block-delete-p block) t))
(dolist (fun (component-lambdas component))
(setf (functional-kind fun) nil)
(setf (leaf-refs fun) nil)
(delete-lambda fun))
(do-blocks (block component)
(delete-block block))
(undefined-value))
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;;; EXTRACT-FUNCTION-ARGS -- interface
;;;
;;; Convert code of the form (foo ... (fun ...) ...) to (foo ... ... ...).
;;; In other words, replace the function combination fun by it's arguments.
;;; If there are any problems with doing this, use GIVE-UP to blow out of
;;; whatever transform called this. Note, as the number of arguments changes,
;;; the transform must be prepared to return a lambda with a new lambda-list
;;; with the correct number of arguments.
;;;
(defun extract-function-args (cont fun num-args)
"If CONT is a call to FUN with NUM-ARGS args, change those arguments
to feed directly to the continuation-dest of CONT, which must be
a combination."
(declare (type continuation cont)
(type symbol fun)
(type index num-args))
(let ((outside (continuation-dest cont))
(inside (continuation-use cont)))
(assert (combination-p outside))
(unless (combination-p inside)
(give-up))
(let ((inside-fun (combination-fun inside)))
(unless (eq (continuation-function-name inside-fun) fun)
(give-up))
(let ((inside-args (combination-args inside)))
(unless (= (length inside-args) num-args)
(give-up))
(let* ((outside-args (combination-args outside))
(arg-position (position cont outside-args))
(before-args (subseq outside-args 0 arg-position))
(after-args (subseq outside-args (1+ arg-position))))
(dolist (arg inside-args)
(setf (continuation-dest arg) outside))
(setf (combination-args inside) nil)
(setf (combination-args outside)
(append before-args inside-args after-args))
(change-ref-leaf (continuation-use inside-fun)
(find-free-function 'list "???"))
(setf (combination-kind inside) :full)
(setf (node-derived-type inside) *wild-type*)
(flush-dest cont)
(setf (continuation-asserted-type cont) *wild-type*)
(undefined-value))))))
;;;; Leaf hackery:
;;; Change-Ref-Leaf -- Interface
;;;
;;; Change the Leaf that a Ref refers to.
;;;
(defun change-ref-leaf (ref leaf)
(declare (type ref ref) (type leaf leaf))
(unless (eq (ref-leaf ref) leaf)
(push ref (leaf-refs leaf))
(delete-ref ref)
(setf (ref-leaf ref) leaf)
(let ((ltype (leaf-type leaf)))
(if (function-type-p ltype)
(setf (node-derived-type ref) ltype)
(derive-node-type ref ltype)))
(reoptimize-continuation (node-cont ref)))
(undefined-value))
;;; Substitute-Leaf -- Interface
;;;
;;; Change all Refs for Old-Leaf to New-Leaf.
;;;
(defun substitute-leaf (new-leaf old-leaf)
(declare (type leaf new-leaf old-leaf))
(dolist (ref (leaf-refs old-leaf))
(change-ref-leaf ref new-leaf))
(undefined-value))
;;; SUBSTITUTE-LEAF-IF -- Interface
;;;
;;; Like SUBSITIUTE-LEAF, only there is a predicate on the Ref to tell
;;; whether to substitute.
;;;
(defun substitute-leaf-if (test new-leaf old-leaf)
(declare (type leaf new-leaf old-leaf) (type function test))
(dolist (ref (leaf-refs old-leaf))
(when (funcall test ref)
(change-ref-leaf ref new-leaf)))
(undefined-value))
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;;; Find-Constant -- Interface
;;;
;;; Return a Leaf which represents the specified constant object. If the
;;; object is not in *constants*, then we create a new constant Leaf and
;;; enter it.
;;;
(defun find-constant (object)
(or (gethash object *constants*)
(setf (gethash object *constants*)
(make-constant :value object :name nil
:type (ctype-of object)
:where-from :defined))))
;;;; Find-NLX-Info -- Interface
;;;
;;; If there is a non-local exit noted in Entry's environment that exits to
;;; Cont in that entry, then return it, otherwise return NIL.
;;;
(defun find-nlx-info (entry cont)
(declare (type entry entry) (type continuation cont))
(let ((entry-cleanup (entry-cleanup entry)))
(dolist (nlx (environment-nlx-info (node-environment entry)) nil)
(eq (nlx-info-cleanup nlx) entry-cleanup))
(return nlx)))))
;;;; Functional hackery:
;;; Main-Entry -- Interface
;;;
;;; If Functional is a Lambda, just return it; if it is an
;;; optional-dispatch, return the main-entry.
;;;
(proclaim '(function main-entry (functional) clambda))
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(defun main-entry (functional)
(if (lambda-p functional)
functional
(optional-dispatch-main-entry functional)))
;;; Looks-Like-An-MV-Bind -- Interface
;;;
;;; Returns true if Functional is a thing that can be treated like MV-Bind
;;; when it appears in an MV-Call. All fixed arguments must be optional with
;;; null default and no supplied-p. There must be a rest arg with no
;;; references.
;;;
(proclaim '(function looks-like-an-mv-bind (functional) boolean))
(defun looks-like-an-mv-bind (functional)
(and (optional-dispatch-p functional)
(do ((arg (optional-dispatch-arglist functional) (cdr arg)))
((null arg) nil)
(let ((info (lambda-var-arg-info (car arg))))
(unless info (return nil))
(case (arg-info-kind info)
(:optional
(when (or (arg-info-supplied-p info) (arg-info-default info))
(return nil)))
(:rest
(return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
(t
(return nil)))))))
;;; External-Entry-Point-P -- Interface
;;;
;;; Return true if function is an XEP. This is true of normal XEPs
;;; (:External kind) and top-level lambdas (:Top-Level kind.)
;;;
(defun external-entry-point-p (fun)
(declare (type functional fun))
(not (null (member (functional-kind fun) '(:external :top-level)))))
;;; Continuation-Function-Name -- Interface
;;;
;;; If Cont's only use is a non-notinline global function reference, then
;;; return the referenced symbol, otherwise NIL. If Notinline-OK is true, then
;;; we don't care if the ref is notinline.
(defun continuation-function-name (cont &optional notinline-ok)
(declare (type continuation cont))
(let ((use (continuation-use cont)))
(if (and (ref-p use)
(or (not (eq (ref-inlinep use) :notinline))
notinline-ok))
(let ((leaf (ref-leaf use)))
(if (and (global-var-p leaf)
(eq (global-var-kind leaf) :global-function))
(leaf-name leaf)
nil))
nil)))
;;; LET-COMBINATION -- Interface
;;;
;;; Return the COMBINATION node that is the call to the let Fun.
;;;
(defun let-combination (fun)
(declare (type clambda fun))
(assert (member (functional-kind fun) '(:let :mv-let)))
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(continuation-dest (node-cont (first (leaf-refs fun)))))
;;; LET-VAR-INITIAL-VALUE -- Interface
;;;
;;; Return the initial value continuation for a let variable or NIL if none.
;;;
(defun let-var-initial-value (var)
(declare (type lambda-var var))
(let ((fun (lambda-var-home var)))
(elt (combination-args (let-combination fun))
(position var (lambda-vars fun)))))
;;; COMBINATION-LAMBDA -- Interface
;;;
;;; Return the LAMBDA that is called by the local Call.
;;;
(defun combination-lambda (call)
(declare (type basic-combination call))
(assert (eq (basic-combination-kind call) :local))
(ref-leaf (continuation-use (basic-combination-fun call))))
;;;; Compiler error context determination:
(proclaim '(special *current-path*))
;;; We bind print level and length when printing out messages so that we don't
;;; dump huge amounts of garbage.
;;;
(proclaim '(type (or unsigned-byte null) *error-print-level*
*error-print-length* *error-print-lines*))
(defvar *error-print-level* 3
"The value for *Print-Level* when printing compiler error messages.")
(defvar *error-print-length* 5
"The value for *Print-Length* when printing compiler error messages.")
(defvar *error-print-lines* 5
"The value for *Print-Lines* when printing compiler error messages.")
(defvar *enclosing-source-cutoff* 1
"The maximum number of enclosing non-original source forms (i.e. from
macroexpansion) that we print in full. For additional enclosing forms, we
print only the CAR.")
(proclaim '(type unsigned-byte *enclosing-source-cutoff*))
;;; We separate the determination of compiler error contexts from the actual
;;; signalling of those errors by objectifying the error context. This allows
;;; postponement of the determination of how (and if) to signal the error.
;;; We take care not to reference any of the IR1 so that pending potential
;;; error messages won't prevent the IR1 from being GC'd. To this end, we
;;; convert source forms to strings so that source forms that contain IR1
;;; references (e.g. %DEFUN) don't hold onto the IR.
;;;
(defstruct (compiler-error-context
(:print-function
(lambda (s stream d)
(declare (ignore s d))
(format stream "#<Compiler-Error-Context>"))))
;;
;; A list of the stringified CARs of the enclosing non-original source forms
;; exceeding the *enclosing-source-cutoff*.
(enclosing-source nil :type list)
;; A list of stringified enclosing non-original source forms.
(source nil :type list)
;; The stringified form in the original source that expanded into Source.
(original-source (required-argument) :type simple-string)
;; A list of prefixes of "interesting" forms that enclose original-source.
(context nil :type list)
;;
;; The FILE-INFO-NAME for the relevant FILE-INFO.
(file-name (required-argument)
:type (or simple-string (member :lisp :stream)))
;;
;; The file position at which the top-level form starts, if applicable.
(file-position nil :type (or index null))
;;
;; The original source part of the source path.
(original-source-path nil :type list))
;;; If true, this is the node which is used as context in compiler warning
;;; messages.
;;;
(proclaim '(type (or null compiler-error-context node)
*compiler-error-context*))
(defvar *compiler-error-context* nil)
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;;; Hashtable mapping macro names to source context parsers. Each parser
;;; function returns the source-context list for that form.
;;;
(defvar *source-context-methods* (make-hash-table))
;;; DEF-SOURCE-CONTEXT -- Public
;;;
(defmacro def-source-context (name ll &body body)
"DEF-SOURCE-CONTEXT Name Lambda-List Form*
This macro defines how to extract an abbreviated source context from the
Named form when it appears in the compiler input. Lambda-List is a DEFMACRO
style lambda-list used to parse the arguments. The Body should return a
list of subforms suitable for a \"~{~S ~}\" format string."
(let ((n-whole (gensym)))
`(setf (gethash ',name *source-context-methods*)
#'(lambda (,n-whole)
(destructuring-bind ,ll ,n-whole ,@body)))))
(def-source-context defstruct (name-or-options &rest slots)
(declare (ignore slots))
`(defstruct ,(if (consp name-or-options)
(car name-or-options)
name-or-options)))
(def-source-context function (thing)
(if (and (consp thing) (eq (first thing) 'lambda) (consp (rest thing)))
`(lambda ,(second thing))
`(function ,thing)))
#+pcl
(def-source-context pcl::defmethod (name &rest stuff)
(let ((arg-pos (position-if #'listp stuff)))
(if arg-pos
`(pcl::defmethod ,name ,@(subseq stuff 0 arg-pos)
,@(nth-value 2 (pcl::parse-specialized-lambda-list
(elt stuff arg-pos))))
;;; SOURCE-FORM-CONTEXT -- Internal
;;;
;;; Return the first two elements of Form if Form is a list. Take the car
;;; of the second form if appropriate.
;;;
(defun source-form-context (form)
(cond ((atom form) nil)
((>= (length form) 2)
(funcall (gethash (first form) *source-context-methods*
#'(lambda (x)
(declare (ignore x))
(list (first form) (second form))))
(rest form)))
;;; Find-Original-Source -- Internal
;;;
;;; Given a source path, return the original source form and a description
;;; of the interesting aspects of the context in which it appeared. The
;;; context is a list of lists, one sublist per context form. The sublist is a
;;; list of some of the initial subforms of the context form.
;;;
;;; For now, we use the first two subforms of each interesting form. A form is
;;; interesting if the first element is a symbol beginning with "DEF" and it is
;;; not the source form. If there is no DEF-mumble, then we use the outermost
;;; containing form. If the second subform is a list, then in some cases we
;;; return the car of that form rather than the whole form (i.e. don't show
;;; defstruct options, etc.)
;;;
(defun find-original-source (path)
(declare (list path))
(let* ((rpath (reverse (source-path-original-source path)))
(tlf (first rpath))
(root (find-source-root tlf *source-info*)))
(collect ((context))
(let ((form root)
(current (rest rpath)))
(loop
(when (atom form)
(assert (null current))
(return))
(let ((head (first form)))
(when (symbolp head)
(let ((name (symbol-name head)))
(when (and (>= (length name) 3) (string= name "DEF" :end1 3))
(context (source-form-context form))))))
(when (null current) (return))
(setq form (nth (pop current) form)))
(cond ((context)
(values form (context)))
((and path root)
(let ((c (source-form-context root)))
(values form (if c (list c) nil))))
(t
(values '(unable to locate source)
'((some strange place)))))))))
;;; STRINGIFY-FORM -- Internal
;;;
;;; Convert a source form to a string, formatted suitably for use in
;;; compiler warnings.
;;;
(defun stringify-form (form &optional (pretty t))
(let ((*print-level* (or *error-print-level* *print-level*))
(*print-length* (or *error-print-length* *print-length*))
(*print-lines* (or *error-print-lines* *print-lines*))
(*print-pretty* pretty))
(if pretty
(format nil " ~S~%" form)
(prin1-to-string form))))
;;; FIND-ERROR-CONTEXT -- Interface
;;;
;;; Return a COMPILER-ERROR-CONTEXT structure describing the current error
;;; context, or NIL if we can't figure anything out. Args is a list of things
;;; that are going to be printed out in the error message, and can thus be
;;; blown off when they appear in the source context.
(defun find-error-context (args)
(let ((context *compiler-error-context*))
(if (compiler-error-context-p context)
context
(let ((path (or *current-path*
(if context
(node-source-path context)
nil))))
(when (and *source-info* path)
(multiple-value-bind (form src-context)
(find-original-source path)
(collect ((full nil cons)
(short nil cons))
(let ((forms (source-path-forms path))
(n 0))
(dolist (src (if (member (first forms) args)
(rest forms)
forms))
(if (>= n *enclosing-source-cutoff*)
(short (stringify-form (if (consp src)
(car src)
src)
nil))
(full (stringify-form src)))
(incf n)))
(let* ((tlf (source-path-tlf-number path))
(file (find-file-info tlf *source-info*)))
(make-compiler-error-context
:enclosing-source (short)
:source (full)
:original-source (stringify-form form)
:context src-context
:file-name (file-info-name file)
:file-position
(multiple-value-bind (ignore pos)
(find-source-root tlf *source-info*)
(declare (ignore ignore))
pos)
:original-source-path
(source-path-original-source path))))))))))
;;;; Printing error messages:
;;; A function that is called to unwind out of Compiler-Error.
;;;
(proclaim '(type (function () nil) *compiler-error-bailout*))
(defvar *compiler-error-bailout*
#'(lambda () (error "Compiler-Error with no bailout.")))
;;; The stream that compiler error output is directed to.
;;;
(defvar *compiler-error-output* (make-synonym-stream '*error-output*))
(proclaim '(type stream *compiler-error-output*))
;;; We save the context information that we printed out most recently so that
;;; we don't print it out redundantly.
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