1 ;;;; structures for the first intermediate representation in the
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
15 ;;; The front-end data structure (IR1) is composed of nodes and
16 ;;; continuations. The general idea is that continuations contain
17 ;;; top-down information and nodes contain bottom-up, derived
18 ;;; information. A continuation represents a place in the code, while
19 ;;; a node represents code that does something.
21 ;;; This representation is more of a flow-graph than an augmented
22 ;;; syntax tree. The evaluation order is explicitly represented in the
23 ;;; linkage by continuations, rather than being implicit in the nodes
24 ;;; which receive the the results of evaluation. This allows us to
25 ;;; decouple the flow of results from the flow of control. A
26 ;;; continuation represents both, but the continuation can represent
27 ;;; the case of a discarded result by having no DEST.
29 (def!struct (continuation
30 (:make-load-form-fun ignore-it)
31 (:constructor make-continuation (&optional dest)))
32 ;; An indication of the way that this continuation is currently used:
35 ;; A continuation for which all control-related slots have the
36 ;; default values. A continuation is unused during IR1 conversion
37 ;; until it is assigned a block, and may be also be temporarily
38 ;; unused during later manipulations of IR1. In a consistent
39 ;; state there should never be any mention of :UNUSED
40 ;; continuations. Next can have a non-null value if the next node
41 ;; has already been determined.
44 ;; A continuation that has been deleted from IR1. Any pointers into
45 ;; IR1 are cleared. There are two conditions under which a deleted
46 ;; continuation may appear in code:
47 ;; -- The CONT of the LAST node in a block may be a deleted
48 ;; continuation when the original receiver of the continuation's
49 ;; value was deleted. Note that DEST in a deleted continuation is
50 ;; null, so it is easy to know not to attempt delivering any
51 ;; values to the continuation.
52 ;; -- Unreachable code that hasn't been deleted yet may receive
53 ;; deleted continuations. All such code will be in blocks that
54 ;; have DELETE-P set. All unreachable code is deleted by control
55 ;; optimization, so the backend doesn't have to worry about this.
58 ;; The continuation that is the START of BLOCK. This is the only kind
59 ;; of continuation that can have more than one use. The BLOCK's
60 ;; START-USES is a list of all the uses.
62 ;; :DELETED-BLOCK-START
63 ;; Like :BLOCK-START, but BLOCK has been deleted. A block
64 ;; starting continuation is made into a deleted block start when
65 ;; the block is deleted, but the continuation still may have
66 ;; value semantics. Since there isn't any code left, next is
70 ;; A continuation that is the CONT of some node in BLOCK.
71 (kind :unused :type (member :unused :deleted :inside-block :block-start
72 :deleted-block-start))
73 ;; The node which receives this value, if any. In a deleted continuation,
74 ;; this is null even though the node that receives this continuation may not
76 (dest nil :type (or node null))
77 ;; If this is a NODE, then it is the node which is to be evaluated
78 ;; next. This is always null in :DELETED and :UNUSED continuations,
79 ;; and will be null in a :INSIDE-BLOCK continuation when this is the
81 (next nil :type (or node null))
82 ;; an assertion on the type of this continuation's value
83 (asserted-type *wild-type* :type ctype)
84 ;; cached type of this continuation's value. If NIL, then this must
85 ;; be recomputed: see CONTINUATION-DERIVED-TYPE.
86 (%derived-type nil :type (or ctype null))
87 ;; Node where this continuation is used, if unique. This is always
88 ;; null in :DELETED and :UNUSED continuations, and is never null in
89 ;; :INSIDE-BLOCK continuations. In a :BLOCK-START continuation, the
90 ;; Block's START-USES indicate whether NIL means no uses or more
92 (use nil :type (or node null))
93 ;; the basic block this continuation is in. This is null only in
94 ;; :DELETED and :UNUSED continuations. Note that blocks that are
95 ;; unreachable but still in the DFO may receive deleted
96 ;; continuations, so it isn't o.k. to assume that any continuation
97 ;; that you pick up out of its DEST node has a BLOCK.
98 (block nil :type (or cblock null))
99 ;; set to true when something about this continuation's value has
100 ;; changed. See REOPTIMIZE-CONTINUATION. This provides a way for IR1
101 ;; optimize to determine which operands to a node have changed. If
102 ;; the optimizer for this node type doesn't care, it can elect not
103 ;; to clear this flag.
104 (reoptimize t :type boolean)
105 ;; an indication of what we have proven about how this contination's
106 ;; type assertion is satisfied:
109 ;; No type check is necessary (proven type is a subtype of the assertion.)
112 ;; A type check is needed.
115 ;; Don't do a type check, but believe (intersect) the assertion.
116 ;; A T check can be changed to :DELETED if we somehow prove the
117 ;; check is unnecessary, or if we eliminate it through a policy
121 ;; Type check generation sets the slot to this if a check is
122 ;; called for, but it believes it has proven that the check won't
123 ;; be done for policy reasons or because a safe implementation
124 ;; will be used. In the latter case, LTN must ensure that a safe
125 ;; implementation *is* used.
128 ;; There is a compile-time type error in some use of this
129 ;; continuation. A type check should still be generated, but be
132 ;; This is computed lazily by CONTINUATION-DERIVED-TYPE, so use
133 ;; CONTINUATION-TYPE-CHECK instead of the %'ed slot accessor.
134 (%type-check t :type (member t nil :deleted :no-check :error))
135 ;; something or other that the back end annotates this continuation with
137 ;; uses of this continuation in the lexical environment. They are
138 ;; recorded so that when one continuation is substituted for another
139 ;; the environment may be updated properly.
140 (lexenv-uses nil :type list))
142 (def!method print-object ((x continuation) stream)
143 (print-unreadable-object (x stream :type t :identity t)))
145 (defstruct (node (:constructor nil)
147 ;; the bottom-up derived type for this node. This does not take into
148 ;; consideration output type assertions on this node (actually on its CONT).
149 (derived-type *wild-type* :type ctype)
150 ;; True if this node needs to be optimized. This is set to true
151 ;; whenever something changes about the value of a continuation
152 ;; whose DEST is this node.
153 (reoptimize t :type boolean)
154 ;; the continuation which receives the value of this node. This also
155 ;; indicates what we do controlwise after evaluating this node. This
156 ;; may be null during IR1 conversion.
157 (cont nil :type (or continuation null))
158 ;; the continuation that this node is the next of. This is null
159 ;; during IR1 conversion when we haven't linked the node in yet or
160 ;; in nodes that have been deleted from the IR1 by UNLINK-NODE.
161 (prev nil :type (or continuation null))
162 ;; the lexical environment this node was converted in
163 (lexenv *lexenv* :type lexenv)
164 ;; a representation of the source code responsible for generating
167 ;; For a form introduced by compilation (does not appear in the
168 ;; original source), the path begins with a list of all the
169 ;; enclosing introduced forms. This list is from the inside out,
170 ;; with the form immediately responsible for this node at the head
173 ;; Following the introduced forms is a representation of the
174 ;; location of the enclosing original source form. This transition
175 ;; is indicated by the magic ORIGINAL-SOURCE-START marker. The first
176 ;; element of the original source is the "form number", which is the
177 ;; ordinal number of this form in a depth-first, left-to-right walk
178 ;; of the truly top-level form in which this appears.
180 ;; Following is a list of integers describing the path taken through
181 ;; the source to get to this point:
182 ;; (K L M ...) => (NTH K (NTH L (NTH M ...)))
184 ;; The last element in the list is the top-level form number, which
185 ;; is the ordinal number (in this call to the compiler) of the truly
186 ;; top-level form containing the original source.
187 (source-path *current-path* :type list)
188 ;; If this node is in a tail-recursive position, then this is set to
189 ;; T. At the end of IR1 (in environment analysis) this is computed
190 ;; for all nodes (after cleanup code has been emitted). Before then,
191 ;; a non-null value indicates that IR1 optimization has converted a
192 ;; tail local call to a direct transfer.
194 ;; If the back-end breaks tail-recursion for some reason, then it
195 ;; can null out this slot.
196 (tail-p nil :type boolean))
198 ;;; Flags that are used to indicate various things about a block, such
199 ;;; as what optimizations need to be done on it:
200 ;;; -- REOPTIMIZE is set when something interesting happens the uses of a
201 ;;; continuation whose Dest is in this block. This indicates that the
202 ;;; value-driven (forward) IR1 optimizations should be done on this block.
203 ;;; -- FLUSH-P is set when code in this block becomes potentially flushable,
204 ;;; usually due to a continuation's DEST becoming null.
205 ;;; -- TYPE-CHECK is true when the type check phase should be run on this
206 ;;; block. IR1 optimize can introduce new blocks after type check has
207 ;;; already run. We need to check these blocks, but there is no point in
208 ;;; checking blocks we have already checked.
209 ;;; -- DELETE-P is true when this block is used to indicate that this block
210 ;;; has been determined to be unreachable and should be deleted. IR1
211 ;;; phases should not attempt to examine or modify blocks with DELETE-P
212 ;;; set, since they may:
213 ;;; - be in the process of being deleted, or
214 ;;; - have no successors, or
215 ;;; - receive :DELETED continuations.
216 ;;; -- TYPE-ASSERTED, TEST-MODIFIED
217 ;;; These flags are used to indicate that something in this block
218 ;;; might be of interest to constraint propagation. TYPE-ASSERTED
219 ;;; is set when a continuation type assertion is strengthened.
220 ;;; TEST-MODIFIED is set whenever the test for the ending IF has
221 ;;; changed (may be true when there is no IF.)
222 (def-boolean-attribute block
223 reoptimize flush-p type-check delete-p type-asserted test-modified)
225 (macrolet ((frob (slot)
226 `(defmacro ,(symbolicate "BLOCK-" slot) (block)
227 `(block-attributep (block-flags ,block) ,',slot))))
233 (frob test-modified))
235 ;;; The CBLOCK structure represents a basic block. We include
236 ;;; SSET-ELEMENT so that we can have sets of blocks. Initially the
237 ;;; SSET-ELEMENT-NUMBER is null, DFO analysis numbers in reverse DFO.
238 ;;; During IR2 conversion, IR1 blocks are re-numbered in forward emit
239 ;;; order. This latter numbering also forms the basis of the block
240 ;;; numbering in the debug-info (though that is relative to the start
241 ;;; of the function.)
242 (defstruct (cblock (:include sset-element)
243 (:constructor make-block (start))
244 (:constructor make-block-key)
247 (:copier copy-block))
248 ;; a list of all the blocks that are predecessors/successors of this
249 ;; block. In well-formed IR1, most blocks will have one successor.
250 ;; The only exceptions are:
251 ;; 1. component head blocks (any number)
252 ;; 2. blocks ending in an IF (1 or 2)
253 ;; 3. blocks with DELETE-P set (zero)
254 (pred nil :type list)
255 (succ nil :type list)
256 ;; the continuation which heads this block (either a :BLOCK-START or
257 ;; :DELETED-BLOCK-START), or NIL when we haven't made the start
258 ;; continuation yet (and in the dummy component head and tail
260 (start nil :type (or continuation null))
261 ;; a list of all the nodes that have START as their CONT
262 (start-uses nil :type list)
263 ;; the last node in this block. This is NIL when we are in the
264 ;; process of building a block (and in the dummy component head and
266 (last nil :type (or node null))
267 ;; the forward and backward links in the depth-first ordering of the
268 ;; blocks. These slots are NIL at beginning/end.
269 (next nil :type (or null cblock))
270 (prev nil :type (or null cblock))
271 ;; This block's attributes: see above.
272 (flags (block-attributes reoptimize flush-p type-check type-asserted
275 ;; Some sets used by constraint propagation.
280 ;; the component this block is in, or NIL temporarily during IR1
281 ;; conversion and in deleted blocks
282 (component *current-component* :type (or component null))
283 ;; a flag used by various graph-walking code to determine whether
284 ;; this block has been processed already or what. We make this
285 ;; initially NIL so that FIND-INITIAL-DFO doesn't have to scan the
286 ;; entire initial component just to clear the flags.
288 ;; Some kind of info used by the back end.
290 ;; If true, then constraints that hold in this block and its
291 ;; successors by merit of being tested by its IF predecessor.
292 (test-constraint nil :type (or sset null)))
293 (def!method print-object ((cblock cblock) stream)
294 (print-unreadable-object (cblock stream :type t :identity t)
295 (format stream ":START c~D" (cont-num (block-start cblock)))))
297 ;;; The Block-Annotation structure is shared (via :INCLUDE) by
298 ;;; different block-info annotation structures so that code
299 ;;; (specifically control analysis) can be shared.
300 (defstruct (block-annotation (:constructor nil)
302 ;; The IR1 block that this block is in the INFO for.
303 (block (required-argument) :type cblock)
304 ;; the next and previous block in emission order (not DFO). This
305 ;; determines which block we drop though to, and also used to chain
306 ;; together overflow blocks that result from splitting of IR2 blocks
307 ;; in lifetime analysis.
308 (next nil :type (or block-annotation null))
309 (prev nil :type (or block-annotation null)))
311 ;;; The Component structure provides a handle on a connected piece of
312 ;;; the flow graph. Most of the passes in the compiler operate on
313 ;;; components rather than on the entire flow graph.
314 (defstruct (component (:copier nil))
315 ;; The kind of component:
318 ;; An ordinary component, containing non-top-level code.
321 ;; A component containing only load-time code.
323 ;; :Complex-Top-Level
324 ;; A component containing both top-level and run-time code.
327 ;; The result of initial IR1 conversion, on which component
328 ;; analysis has not been done.
331 ;; Debris left over from component analysis.
332 (kind nil :type (member nil :top-level :complex-top-level :initial :deleted))
333 ;; The blocks that are the dummy head and tail of the DFO.
334 ;; Entry/exit points have these blocks as their
335 ;; predecessors/successors. Null temporarily. The start and return
336 ;; from each non-deleted function is linked to the component head
337 ;; and tail. Until environment analysis links NLX entry stubs to the
338 ;; component head, every successor of the head is a function start
339 ;; (i.e. begins with a Bind node.)
340 (head nil :type (or null cblock))
341 (tail nil :type (or null cblock))
342 ;; A list of the CLambda structures for all functions in this
343 ;; component. Optional-Dispatches are represented only by their XEP
344 ;; and other associated lambdas. This doesn't contain any deleted or
346 (lambdas () :type list)
347 ;; A list of Functional structures for functions that are newly
348 ;; converted, and haven't been local-call analyzed yet. Initially
349 ;; functions are not in the Lambdas list. LOCAL-CALL-ANALYZE moves
350 ;; them there (possibly as LETs, or implicitly as XEPs if an
351 ;; OPTIONAL-DISPATCH.) Between runs of LOCAL-CALL-ANALYZE there may
352 ;; be some debris of converted or even deleted functions in this
354 (new-functions () :type list)
355 ;; If true, then there is stuff in this component that could benefit
356 ;; from further IR1 optimization.
357 (reoptimize t :type boolean)
358 ;; If true, then the control flow in this component was messed up by
359 ;; IR1 optimizations. The DFO should be recomputed.
360 (reanalyze nil :type boolean)
361 ;; String that is some sort of name for the code in this component.
362 (name "<unknown>" :type simple-string)
363 ;; Some kind of info used by the back end.
365 ;; The Source-Info structure describing where this component was
367 (source-info *source-info* :type source-info)
368 ;; Count of the number of inline expansions we have done while
369 ;; compiling this component, to detect infinite or exponential
371 (inline-expansions 0 :type index)
372 ;; A hashtable from combination nodes to things describing how an
373 ;; optimization of the node failed. The value is an alist (Transform
374 ;; . Args), where Transform is the structure describing the
375 ;; transform that failed, and Args is either a list of format
376 ;; arguments for the note, or the FUNCTION-TYPE that would have
377 ;; enabled the transformation but failed to match.
378 (failed-optimizations (make-hash-table :test 'eq) :type hash-table)
379 ;; Similar to NEW-FUNCTIONS, but is used when a function has already
380 ;; been analyzed, but new references have been added by inline
381 ;; expansion. Unlike NEW-FUNCTIONS, this is not disjoint from
382 ;; COMPONENT-LAMBDAS.
383 (reanalyze-functions nil :type list))
384 (defprinter (component)
386 (reanalyze :test reanalyze))
388 ;;; The CLEANUP structure represents some dynamic binding action.
389 ;;; Blocks are annotated with the current cleanup so that dynamic
390 ;;; bindings can be removed when control is transferred out of the
391 ;;; binding environment. We arrange for changes in dynamic bindings to
392 ;;; happen at block boundaries, so that cleanup code may easily be
393 ;;; inserted. The "mess-up" action is explicitly represented by a
394 ;;; funny function call or Entry node.
396 ;;; We guarantee that cleanups only need to be done at block boundaries
397 ;;; by requiring that the exit continuations initially head their
398 ;;; blocks, and then by not merging blocks when there is a cleanup
400 (defstruct (cleanup (:copier nil))
401 ;; The kind of thing that has to be cleaned up.
402 (kind (required-argument)
403 :type (member :special-bind :catch :unwind-protect :block :tagbody))
404 ;; The node that messes things up. This is the last node in the
405 ;; non-messed-up environment. Null only temporarily. This could be
406 ;; deleted due to unreachability.
407 (mess-up nil :type (or node null))
408 ;; A list of all the NLX-Info structures whose NLX-Info-Cleanup is
409 ;; this cleanup. This is filled in by environment analysis.
410 (nlx-info nil :type list))
411 (defprinter (cleanup)
414 (nlx-info :test nlx-info))
416 ;;; The ENVIRONMENT structure represents the result of environment analysis.
417 (defstruct (environment (:copier nil))
418 ;; the function that allocates this environment
419 (function (required-argument) :type clambda)
420 ;; a list of all the lambdas that allocate variables in this environment
421 (lambdas nil :type list)
422 ;; a list of all the lambda-vars and NLX-Infos needed from enclosing
423 ;; environments by code in this environment
424 (closure nil :type list)
425 ;; a list of NLX-Info structures describing all the non-local exits
426 ;; into this environment
427 (nlx-info nil :type list)
428 ;; some kind of info used by the back end
430 (defprinter (environment)
432 (closure :test closure)
433 (nlx-info :test nlx-info))
435 ;;; The TAIL-SET structure is used to accumulate information about
436 ;;; tail-recursive local calls. The "tail set" is effectively the
437 ;;; transitive closure of the "is called tail-recursively by"
440 ;;; All functions in the same tail set share the same TAIL-SET
441 ;;; structure. Initially each function has its own TAIL-SET, but when
442 ;;; IR1-OPTIMIZE-RETURN notices a tail local call, it joins the tail
443 ;;; sets of the called function and the calling function.
445 ;;; The tail set is somewhat approximate, because it is too early to
446 ;;; be sure which calls will be TR. Any call that *might* end up TR
447 ;;; causes tail-set merging.
448 (defstruct (tail-set (:copier nil))
449 ;; a list of all the lambdas in this tail set
450 (functions nil :type list)
451 ;; our current best guess of the type returned by these functions.
452 ;; This is the union across all the functions of the return node's
453 ;; RESULT-TYPE. excluding local calls.
454 (type *wild-type* :type ctype)
455 ;; some info used by the back end
457 (defprinter (tail-set)
462 ;;; The NLX-Info structure is used to collect various information
463 ;;; about non-local exits. This is effectively an annotation on the
464 ;;; CONTINUATION, although it is accessed by searching in the
465 ;;; ENVIRONMENT-NLX-INFO.
466 (def!struct (nlx-info (:make-load-form-fun ignore-it))
467 ;; the cleanup associated with this exit. In a catch or
468 ;; unwind-protect, this is the :CATCH or :UNWIND-PROTECT cleanup,
469 ;; and not the cleanup for the escape block. The CLEANUP-KIND of
470 ;; this thus provides a good indication of what kind of exit is
472 (cleanup (required-argument) :type cleanup)
473 ;; the continuation exited to (the CONT of the EXIT nodes). If this
474 ;; exit is from an escape function (CATCH or UNWIND-PROTECT), then
475 ;; environment analysis deletes the escape function and instead has
476 ;; the %NLX-ENTRY use this continuation.
478 ;; This slot is primarily an indication of where this exit delivers
479 ;; its values to (if any), but it is also used as a sort of name to
480 ;; allow us to find the NLX-Info that corresponds to a given exit.
481 ;; For this purpose, the Entry must also be used to disambiguate,
482 ;; since exits to different places may deliver their result to the
483 ;; same continuation.
484 (continuation (required-argument) :type continuation)
485 ;; the entry stub inserted by environment analysis. This is a block
486 ;; containing a call to the %NLX-Entry funny function that has the
487 ;; original exit destination as its successor. Null only
489 (target nil :type (or cblock null))
490 ;; some kind of info used by the back end
492 (defprinter (nlx-info)
499 ;;; Variables, constants and functions are all represented by LEAF
500 ;;; structures. A reference to a LEAF is indicated by a REF node. This
501 ;;; allows us to easily substitute one for the other without actually
502 ;;; hacking the flow graph.
503 (def!struct (leaf (:make-load-form-fun ignore-it)
505 ;; some name for this leaf. The exact significance of the name
506 ;; depends on what kind of leaf it is. In a LAMBDA-VAR or
507 ;; GLOBAL-VAR, this is the symbol name of the variable. In a
508 ;; functional that is from a DEFUN, this is the defined name. In
509 ;; other functionals, this is a descriptive string.
511 ;; the type which values of this leaf must have
512 (type *universal-type* :type ctype)
513 ;; where the TYPE information came from:
514 ;; :DECLARED, from a declaration.
515 ;; :ASSUMED, from uses of the object.
516 ;; :DEFINED, from examination of the definition.
517 ;; FIXME: This should be a named type. (LEAF-WHERE-FROM? Or
518 ;; perhaps just WHERE-FROM, since it's not just used in LEAF,
519 ;; but also in various DEFINE-INFO-TYPEs in globaldb.lisp,
520 ;; and very likely elsewhere too.)
521 (where-from :assumed :type (member :declared :assumed :defined))
522 ;; list of the REF nodes for this leaf
524 ;; true if there was ever a REF or SET node for this leaf. This may
525 ;; be true when REFS and SETS are null, since code can be deleted.
526 (ever-used nil :type boolean)
527 ;; some kind of info used by the back end
530 ;;; The CONSTANT structure is used to represent known constant values.
531 ;;; If NAME is not null, then it is the name of the named constant
532 ;;; which this leaf corresponds to, otherwise this is an anonymous
534 (def!struct (constant (:include leaf))
535 ;; the value of the constant
537 (defprinter (constant)
541 ;;; The BASIC-VAR structure represents information common to all
542 ;;; variables which don't correspond to known local functions.
543 (def!struct (basic-var (:include leaf) (:constructor nil))
544 ;; Lists of the set nodes for this variable.
545 (sets () :type list))
547 ;;; The GLOBAL-VAR structure represents a value hung off of the symbol
548 ;;; NAME. We use a :CONSTANT VAR when we know that the thing is a
549 ;;; constant, but don't know what the value is at compile time.
550 (def!struct (global-var (:include basic-var))
551 ;; kind of variable described
552 (kind (required-argument)
553 :type (member :special :global-function :constant :global)))
554 (defprinter (global-var)
556 (type :test (not (eq type *universal-type*)))
557 (where-from :test (not (eq where-from :assumed)))
560 ;;; The SLOT-ACCESSOR structure represents slot accessor functions. It
561 ;;; is a subtype of GLOBAL-VAR to make it look more like a normal
563 (def!struct (slot-accessor (:include global-var
564 (where-from :defined)
565 (kind :global-function)))
566 ;; The description of the structure that this is an accessor for.
567 (for (required-argument) :type sb!xc:class)
568 ;; The slot description of the slot.
569 (slot (required-argument)))
570 (defprinter (slot-accessor)
575 ;;; The DEFINED-FUNCTION structure represents functions that are
576 ;;; defined in the same compilation block, or that have inline
577 ;;; expansions, or have a non-NIL INLINEP value. Whenever we change
578 ;;; the INLINEP state (i.e. an inline proclamation) we copy the
579 ;;; structure so that former INLINEP values are preserved.
580 (def!struct (defined-function (:include global-var
581 (where-from :defined)
582 (kind :global-function)))
583 ;; The values of INLINEP and INLINE-EXPANSION initialized from the
584 ;; global environment.
585 (inlinep nil :type inlinep)
586 (inline-expansion nil :type (or cons null))
587 ;; The block-local definition of this function (either because it
588 ;; was semi-inline, or because it was defined in this block.) If
589 ;; this function is not an entry point, then this may be deleted or
590 ;; let-converted. Null if we haven't converted the expansion yet.
591 (functional nil :type (or functional null)))
592 (defprinter (defined-function)
595 (functional :test functional))
599 ;;; We default the WHERE-FROM and TYPE slots to :DEFINED and FUNCTION.
600 ;;; We don't normally manipulate function types for defined functions,
601 ;;; but if someone wants to know, an approximation is there.
602 (def!struct (functional (:include leaf
603 (where-from :defined)
604 (type (specifier-type 'function))))
605 ;; Some information about how this function is used. These values are
609 ;; an ordinary function, callable using local call
612 ;; a lambda that is used in only one local call, and has in
613 ;; effect been substituted directly inline. The return node is
614 ;; deleted, and the result is computed with the actual result
615 ;; continuation for the call.
618 ;; Similar to :LET, but the call is an MV-CALL.
621 ;; similar to a LET, but can have other than one call as long as
622 ;; there is at most one non-tail call.
625 ;; a lambda that is an entry-point for an optional-dispatch.
626 ;; Similar to NIL, but requires greater caution, since local call
627 ;; analysis may create new references to this function. Also, the
628 ;; function cannot be deleted even if it has *no* references. The
629 ;; Optional-Dispatch is in the LAMDBA-OPTIONAL-DISPATCH.
632 ;; an external entry point lambda. The function it is an entry
633 ;; for is in the Entry-Function.
636 ;; a top-level lambda, holding a compiled top-level form.
637 ;; Compiled very much like NIL, but provides an indication of
638 ;; top-level context. A top-level lambda should have *no*
639 ;; references. Its Entry-Function is a self-pointer.
642 ;; After a component is compiled, we clobber any top-level code
643 ;; references to its non-closure XEPs with dummy FUNCTIONAL
644 ;; structures having this kind. This prevents the retained
645 ;; top-level code from holding onto the IR for the code it
650 ;; special functions used internally by CATCH and UNWIND-PROTECT.
651 ;; These are pretty much like a normal function (NIL), but are
652 ;; treated specially by local call analysis and stuff. Neither
653 ;; kind should ever be given an XEP even though they appear as
654 ;; args to funny functions. An :ESCAPE function is never actually
655 ;; called, and thus doesn't need to have code generated for it.
658 ;; This function has been found to be uncallable, and has been
659 ;; marked for deletion.
660 (kind nil :type (member nil :optional :deleted :external :top-level :escape
661 :cleanup :let :mv-let :assignment
663 ;; In a normal function, this is the external entry point (XEP)
664 ;; lambda for this function, if any. Each function that is used
665 ;; other than in a local call has an XEP, and all of the
666 ;; non-local-call references are replaced with references to the
669 ;; In an XEP lambda (indicated by the :External kind), this is the
670 ;; function that the XEP is an entry-point for. The body contains
671 ;; local calls to all the actual entry points in the function. In a
672 ;; :Top-Level lambda (which is its own XEP) this is a self-pointer.
674 ;; With all other kinds, this is null.
675 (entry-function nil :type (or functional null))
676 ;; the value of any inline/notinline declaration for a local function
677 (inlinep nil :type inlinep)
678 ;; If we have a lambda that can be used as in inline expansion for
679 ;; this function, then this is it. If there is no source-level
680 ;; lambda corresponding to this function then this is Null (but then
681 ;; INLINEP will always be NIL as well.)
682 (inline-expansion nil :type list)
683 ;; the lexical environment that the inline-expansion should be converted in
684 (lexenv *lexenv* :type lexenv)
685 ;; the original function or macro lambda list, or :UNSPECIFIED if
686 ;; this is a compiler created function
687 (arg-documentation nil :type (or list (member :unspecified)))
688 ;; various rare miscellaneous info that drives code generation & stuff
689 (plist () :type list))
690 (defprinter (functional)
693 ;;; The CLAMBDA only deals with required lexical arguments. Special,
694 ;;; optional, keyword and rest arguments are handled by transforming
695 ;;; into simpler stuff.
696 (def!struct (clambda (:include functional)
698 (:predicate lambda-p)
699 (:constructor make-lambda)
700 (:copier copy-lambda))
701 ;; List of lambda-var descriptors for args.
702 (vars nil :type list)
703 ;; If this function was ever a :OPTIONAL function (an entry-point
704 ;; for an optional-dispatch), then this is that optional-dispatch.
705 ;; The optional dispatch will be :DELETED if this function is no
707 (optional-dispatch nil :type (or optional-dispatch null))
708 ;; The Bind node for this Lambda. This node marks the beginning of
709 ;; the lambda, and serves to explicitly represent the lambda binding
710 ;; semantics within the flow graph representation. Null in deleted
711 ;; functions, and also in LETs where we deleted the call & bind
712 ;; (because there are no variables left), but have not yet actually
713 ;; deleted the lambda yet.
714 (bind nil :type (or bind null))
715 ;; The Return node for this Lambda, or NIL if it has been deleted.
716 ;; This marks the end of the lambda, receiving the result of the
717 ;; body. In a let, the return node is deleted, and the body delivers
718 ;; the value to the actual continuation. The return may also be
719 ;; deleted if it is unreachable.
720 (return nil :type (or creturn null))
721 ;; If this is a let, then the Lambda whose Lets list we are in,
722 ;; otherwise this is a self-pointer.
723 (home nil :type (or clambda null))
724 ;; A list of all the all the lambdas that have been let-substituted
725 ;; in this lambda. This is only non-null in lambdas that aren't
728 ;; A list of all the Entry nodes in this function and its lets. Null
730 (entries () :type list)
731 ;; A list of all the functions directly called from this function
732 ;; (or one of its lets) using a non-let local call. May include
733 ;; deleted functions because nobody bothers to clear them out.
734 (calls () :type list)
735 ;; The Tail-Set that this lambda is in. Null during creation and in
737 (tail-set nil :type (or tail-set null))
738 ;; The structure which represents the environment that this
739 ;; Function's variables are allocated in. This is filled in by
740 ;; environment analysis. In a let, this is EQ to our home's
742 (environment nil :type (or environment null))
743 ;; In a LET, this is the NODE-LEXENV of the combination node. We
744 ;; retain it so that if the let is deleted (due to a lack of vars),
745 ;; we will still have caller's lexenv to figure out which cleanup is
747 (call-lexenv nil :type (or lexenv null)))
748 (defprinter (clambda :conc-name lambda-)
750 (type :test (not (eq type *universal-type*)))
751 (where-from :test (not (eq where-from :assumed)))
752 (vars :prin1 (mapcar #'leaf-name vars)))
754 ;;; The OPTIONAL-DISPATCH leaf is used to represent hairy lambdas. It
755 ;;; is a FUNCTIONAL, like LAMBDA. Each legal number of arguments has a
756 ;;; function which is called when that number of arguments is passed.
757 ;;; The function is called with all the arguments actually passed. If
758 ;;; additional arguments are legal, then the LEXPR style MORE-ENTRY
759 ;;; handles them. The value returned by the function is the value
760 ;;; which results from calling the OPTIONAL-DISPATCH.
762 ;;; The theory is that each entry-point function calls the next entry
763 ;;; point tail-recursively, passing all the arguments passed in and
764 ;;; the default for the argument the entry point is for. The last
765 ;;; entry point calls the real body of the function. In the presence
766 ;;; of supplied-p args and other hair, things are more complicated. In
767 ;;; general, there is a distinct internal function that takes the
768 ;;; supplied-p args as parameters. The preceding entry point calls
769 ;;; this function with NIL filled in for the supplied-p args, while
770 ;;; the current entry point calls it with T in the supplied-p
773 ;;; Note that it is easy to turn a call with a known number of
774 ;;; arguments into a direct call to the appropriate entry-point
775 ;;; function, so functions that are compiled together can avoid doing
777 (def!struct (optional-dispatch (:include functional))
778 ;; the original parsed argument list, for anyone who cares
779 (arglist nil :type list)
780 ;; true if &ALLOW-OTHER-KEYS was supplied
781 (allowp nil :type boolean)
782 ;; true if &KEY was specified (which doesn't necessarily mean that
783 ;; there are any &KEY arguments..)
784 (keyp nil :type boolean)
785 ;; the number of required arguments. This is the smallest legal
786 ;; number of arguments.
787 (min-args 0 :type unsigned-byte)
788 ;; the total number of required and optional arguments. Args at
789 ;; positions >= to this are &REST, &KEY or illegal args.
790 (max-args 0 :type unsigned-byte)
791 ;; list of the LAMBDAs which are the entry points for non-rest,
792 ;; non-key calls. The entry for MIN-ARGS is first, MIN-ARGS+1
793 ;; second, ... MAX-ARGS last. The last entry-point always calls the
794 ;; main entry; in simple cases it may be the main entry.
795 (entry-points nil :type list)
796 ;; An entry point which takes MAX-ARGS fixed arguments followed by
797 ;; an argument context pointer and an argument count. This entry
798 ;; point deals with listifying rest args and parsing keywords. This
799 ;; is null when extra arguments aren't legal.
800 (more-entry nil :type (or clambda null))
801 ;; The main entry-point into the function, which takes all arguments
802 ;; including keywords as fixed arguments. The format of the
803 ;; arguments must be determined by examining the arglist. This may
804 ;; be used by callers that supply at least Max-Args arguments and
805 ;; know what they are doing.
806 (main-entry nil :type (or clambda null)))
807 (defprinter (optional-dispatch)
809 (type :test (not (eq type *universal-type*)))
810 (where-from :test (not (eq where-from :assumed)))
816 (entry-points :test entry-points)
817 (more-entry :test more-entry)
820 ;;; The ARG-INFO structure allows us to tack various information onto
821 ;;; LAMBDA-VARs during IR1 conversion. If we use one of these things,
822 ;;; then the var will have to be massaged a bit before it is simple
825 ;; true if this arg is to be specially bound
826 (specialp nil :type boolean)
827 ;; the kind of argument being described. Required args only have arg
828 ;; info structures if they are special.
829 (kind (required-argument) :type (member :required :optional :keyword :rest
830 :more-context :more-count))
831 ;; If true, this is the VAR for SUPPLIED-P variable of a keyword or
832 ;; optional arg. This is true for keywords with non-constant
833 ;; defaults even when there is no user-specified supplied-p var.
834 (supplied-p nil :type (or lambda-var null))
835 ;; the default for a keyword or optional, represented as the
836 ;; original Lisp code. This is set to NIL in &KEY arguments that are
837 ;; defaulted using the SUPPLIED-P arg.
838 (default nil :type t)
839 ;; the actual key for a &KEY argument. Note that in ANSI CL this is not
840 ;; necessarily a keyword: (DEFUN FOO (&KEY ((BAR BAR))) ..).
841 (key nil :type symbol))
842 (defprinter (arg-info)
843 (specialp :test specialp)
845 (supplied-p :test supplied-p)
846 (default :test default)
849 ;;; The LAMBDA-VAR structure represents a lexical lambda variable.
850 ;;; This structure is also used during IR1 conversion to describe
851 ;;; lambda arguments which may ultimately turn out not to be simple
854 ;;; LAMBDA-VARs with no REFs are considered to be deleted; environment
855 ;;; analysis isn't done on these variables, so the back end must check
856 ;;; for and ignore unreferenced variables. Note that a deleted
857 ;;; lambda-var may have sets; in this case the back end is still
858 ;;; responsible for propagating the Set-Value to the set's Cont.
859 (def!struct (lambda-var (:include basic-var))
860 ;; true if this variable has been declared IGNORE
861 (ignorep nil :type boolean)
862 ;; the CLAMBDA that this var belongs to. This may be null when we are
863 ;; building a lambda during IR1 conversion.
864 (home nil :type (or null clambda))
865 ;; This is set by environment analysis if it chooses an indirect
866 ;; (value cell) representation for this variable because it is both
867 ;; set and closed over.
868 (indirect nil :type boolean)
869 ;; The following two slots are only meaningful during IR1 conversion
870 ;; of hairy lambda vars:
872 ;; The ARG-INFO structure which holds information obtained from
874 (arg-info nil :type (or arg-info null))
875 ;; if true, the GLOBAL-VAR structure for the special variable which
876 ;; is to be bound to the value of this argument
877 (specvar nil :type (or global-var null))
878 ;; Set of the CONSTRAINTs on this variable. Used by constraint
879 ;; propagation. This is left null by the lambda pre-pass if it
880 ;; determine that this is a set closure variable, and is thus not a
881 ;; good subject for flow analysis.
882 (constraints nil :type (or sset null)))
883 (defprinter (lambda-var)
885 (type :test (not (eq type *universal-type*)))
886 (where-from :test (not (eq where-from :assumed)))
887 (ignorep :test ignorep)
888 (arg-info :test arg-info)
889 (specvar :test specvar))
891 ;;;; basic node types
893 ;;; A REF represents a reference to a LEAF. REF-REOPTIMIZE is
894 ;;; initially (and forever) NIL, since REFs don't receive any values
895 ;;; and don't have any IR1 optimizer.
896 (defstruct (ref (:include node (:reoptimize nil))
897 (:constructor make-ref (derived-type leaf))
899 ;; The leaf referenced.
900 (leaf nil :type leaf))
904 ;;; Naturally, the IF node always appears at the end of a block.
905 ;;; NODE-CONT is a dummy continuation, and is there only to keep
907 (defstruct (cif (:include node)
910 (:constructor make-if)
912 ;; CONTINUATION for the predicate
913 (test (required-argument) :type continuation)
914 ;; the blocks that we execute next in true and false case,
915 ;; respectively (may be the same)
916 (consequent (required-argument) :type cblock)
917 (alternative (required-argument) :type cblock))
918 (defprinter (cif :conc-name if-)
919 (test :prin1 (continuation-use test))
923 (defstruct (cset (:include node
924 (derived-type *universal-type*))
927 (:constructor make-set)
929 ;; descriptor for the variable set
930 (var (required-argument) :type basic-var)
931 ;; continuation for the value form
932 (value (required-argument) :type continuation))
933 (defprinter (cset :conc-name set-)
935 (value :prin1 (continuation-use value)))
937 ;;; The BASIC-COMBINATION structure is used to represent both normal
938 ;;; and multiple value combinations. In a local function call, this
939 ;;; node appears at the end of its block and the body of the called
940 ;;; function appears as the successor. The NODE-CONT remains the
941 ;;; continuation which receives the value of the call.
942 (defstruct (basic-combination (:include node)
945 ;; continuation for the function
946 (fun (required-argument) :type continuation)
947 ;; list of CONTINUATIONs for the args. In a local call, an argument
948 ;; continuation may be replaced with NIL to indicate that the
949 ;; corresponding variable is unreferenced, and thus no argument
950 ;; value need be passed.
951 (args nil :type list)
952 ;; the kind of function call being made. :LOCAL means that this is a
953 ;; local call to a function in the same component, and that argument
954 ;; syntax checking has been done, etc. Calls to known global
955 ;; functions are represented by storing the FUNCTION-INFO for the
956 ;; function in this slot. :FULL is a call to an (as yet) unknown
957 ;; function. :ERROR is like :FULL, but means that we have discovered
958 ;; that the call contains an error, and should not be reconsidered
960 (kind :full :type (or (member :local :full :error) function-info))
961 ;; some kind of information attached to this node by the back end
964 ;;; The COMBINATION node represents all normal function calls,
965 ;;; including FUNCALL. This is distinct from BASIC-COMBINATION so that
966 ;;; an MV-COMBINATION isn't COMBINATION-P.
967 (defstruct (combination (:include basic-combination)
968 (:constructor make-combination (fun))
970 (defprinter (combination)
971 (fun :prin1 (continuation-use fun))
972 (args :prin1 (mapcar (lambda (x)
978 ;;; An MV-COMBINATION is to MULTIPLE-VALUE-CALL as a COMBINATION is to
979 ;;; FUNCALL. This is used to implement all the multiple-value
981 (defstruct (mv-combination (:include basic-combination)
982 (:constructor make-mv-combination (fun))
984 (defprinter (mv-combination)
985 (fun :prin1 (continuation-use fun))
986 (args :prin1 (mapcar #'continuation-use args)))
988 ;;; The BIND node marks the beginning of a lambda body and represents
989 ;;; the creation and initialization of the variables.
990 (defstruct (bind (:include node)
992 ;; the lambda we are binding variables for. Null when we are
993 ;; creating the LAMBDA during IR1 translation.
994 (lambda nil :type (or clambda null)))
998 ;;; The RETURN node marks the end of a lambda body. It collects the
999 ;;; return values and represents the control transfer on return. This
1000 ;;; is also where we stick information used for TAIL-SET type
1002 (defstruct (creturn (:include node)
1003 (:conc-name return-)
1004 (:predicate return-p)
1005 (:constructor make-return)
1006 (:copier copy-return))
1007 ;; the lambda we are returning from. Null temporarily during
1009 (lambda nil :type (or clambda null))
1010 ;; the continuation which yields the value of the lambda
1011 (result (required-argument) :type continuation)
1012 ;; the union of the node-derived-type of all uses of the result
1013 ;; other than by a local call, intersected with the result's
1014 ;; asserted-type. If there are no non-call uses, this is
1016 (result-type *wild-type* :type ctype))
1017 (defprinter (creturn :conc-name return-)
1021 ;;;; non-local exit support
1023 ;;;; In IR1, we insert special nodes to mark potentially non-local
1026 ;;; The ENTRY node serves to mark the start of the dynamic extent of a
1027 ;;; lexical exit. It is the mess-up node for the corresponding :Entry
1029 (defstruct (entry (:include node)
1031 ;; All of the Exit nodes for potential non-local exits to this point.
1032 (exits nil :type list)
1033 ;; The cleanup for this entry. NULL only temporarily.
1034 (cleanup nil :type (or cleanup null)))
1035 (defprinter (entry))
1037 ;;; The EXIT node marks the place at which exit code would be emitted,
1038 ;;; if necessary. This is interposed between the uses of the exit
1039 ;;; continuation and the exit continuation's DEST. Instead of using
1040 ;;; the returned value being delivered directly to the exit
1041 ;;; continuation, it is delivered to our VALUE continuation. The
1042 ;;; original exit continuation is the exit node's CONT.
1043 (defstruct (exit (:include node)
1045 ;; The Entry node that this is an exit for. If null, this is a
1046 ;; degenerate exit. A degenerate exit is used to "fill" an empty
1047 ;; block (which isn't allowed in IR1.) In a degenerate exit, Value
1048 ;; is always also null.
1049 (entry nil :type (or entry null))
1050 ;; The continuation yeilding the value we are to exit with. If NIL,
1051 ;; then no value is desired (as in GO).
1052 (value nil :type (or continuation null)))
1055 (value :test value))
1057 ;;;; miscellaneous IR1 structures
1059 (defstruct (undefined-warning
1060 #-no-ansi-print-object
1061 (:print-object (lambda (x s)
1062 (print-unreadable-object (x s :type t)
1063 (prin1 (undefined-warning-name x) s))))
1065 ;; the name of the unknown thing
1066 (name nil :type (or symbol list))
1067 ;; the kind of reference to NAME
1068 (kind (required-argument) :type (member :function :type :variable))
1069 ;; the number of times this thing was used
1070 (count 0 :type unsigned-byte)
1071 ;; a list of COMPILER-ERROR-CONTEXT structures describing places
1072 ;; where this thing was used. Note that we only record the first
1073 ;; *UNDEFINED-WARNING-LIMIT* calls.
1074 (warnings () :type list))
1076 ;;; a helper for the POLICY macro, defined late here so that the
1077 ;;; various type tests can be inlined
1078 (declaim (ftype (function ((or list lexenv node functional)) list)
1080 (defun %coerce-to-policy (thing)
1081 (let ((result (etypecase thing
1083 (lexenv (lexenv-policy thing))
1084 (node (lexenv-policy (node-lexenv thing)))
1085 (functional (lexenv-policy (functional-lexenv thing))))))
1086 ;; Test the first element of the list as a rudimentary sanity
1087 ;; that it really does look like a valid policy.
1088 (aver (or (null result) (policy-quality-name-p (caar result))))
1092 ;;;; Freeze some structure types to speed type testing.
1095 (declaim (freeze-type node leaf lexenv continuation cblock component cleanup
1096 environment tail-set nlx-info))