| blob | 2a92b9894a4957c0cfb60931fdc1e845d1a400fe |
1 ;;;; This file contains code which does the translation of lambda
2 ;;;; forms from Lisp code to the first intermediate representation
3 ;;;; (IR1).
5 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; more information.
7 ;;;;
8 ;;;; This software is derived from the CMU CL system, which was
9 ;;;; written at Carnegie Mellon University and released into the
10 ;;;; public domain. The software is in the public domain and is
11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
12 ;;;; files for more information.
16 ;;;; LAMBDA hackery
18 ;;;; Note: Take a look at the compiler-overview.tex section on "Hairy
19 ;;;; function representation" before you seriously mess with this
20 ;;;; stuff.
22 ;;; Verify that the NAME is a legal name for a variable and return a
23 ;;; VAR structure for it, filling in info if it is globally special.
24 ;;; If it is losing, we punt with a COMPILER-ERROR. NAMES-SO-FAR is a
25 ;;; list of names which have previously been bound. If the NAME is in
26 ;;; this list, then we error out.
34 name))
38 name))
48 ;;; Make the default keyword for a &KEY arg, checking that the keyword
49 ;;; isn't already used by one of the VARS.
54 symbol)))
61 "The keyword ~S appears more than once in the lambda list."
62 key))))
63 key))
65 ;;; Parse a lambda list into a list of VAR structures, stripping off
66 ;;; any &AUX bindings. Each arg name is checked for legality, and
67 ;;; duplicate names are checked for. If an arg is globally special,
68 ;;; the var is marked as :SPECIAL instead of :LEXICAL. &KEY,
69 ;;; &OPTIONAL and &REST args are annotated with an ARG-INFO structure
70 ;;; which contains the extra information. If we hit something losing,
71 ;;; we bug out with COMPILER-ERROR. These values are returned:
72 ;;; 1. a list of the var structures for each top level argument;
73 ;;; 2. a flag indicating whether &KEY was specified;
74 ;;; 3. a flag indicating whether other &KEY args are allowed;
75 ;;; 4. a list of the &AUX variables; and
76 ;;; 5. a list of the &AUX values.
78 make-lambda-vars))
81 morep more-context more-count)
89 ;; for optionals and keywords args.
101 "The list ~S is too long to be an arg specifier."
102 spec)))))))
150 t)))
173 nil))))
188 spec))
197 ;;; This is similar to IR1-CONVERT-PROGN-BODY except that we
198 ;;; sequentially bind each AUX-VAR to the corresponding AUX-VAL before
199 ;;; converting the body. If there are no bindings, just convert the
200 ;;; body, otherwise do one binding and recurse on the rest.
201 ;;;
202 ;;; FIXME: This could and probably should be converted to use
203 ;;; SOURCE-NAME and DEBUG-NAME. But I (WHN) don't use &AUX bindings,
204 ;;; so I'm not motivated. Patches will be accepted...
206 post-binding-lexenv)
218 :post-binding-lexenv post-binding-lexenv
220 '&aux-bindings
221 aux-vars))))
227 ;;; This is similar to IR1-CONVERT-PROGN-BODY except that code to bind
228 ;;; the SPECVAR for each SVAR to the value of the variable is wrapped
229 ;;; around the body. If there are no special bindings, we just convert
230 ;;; the body, otherwise we do one special binding and recurse on the
231 ;;; rest.
232 ;;;
233 ;;; We make a cleanup and introduce it into the lexical
234 ;;; environment. If there are multiple special bindings, the cleanup
235 ;;; for the blocks will end up being the innermost one. We force NEXT
236 ;;; to start a block outside of this cleanup, causing cleanup code to
237 ;;; be emitted when the scope is exited.
245 post-binding-lexenv))
258 body aux-vars aux-vals
260 post-binding-lexenv)))))
263 ;;; Create a lambda node out of some code, returning the result. The
264 ;;; bindings are specified by the list of VAR structures VARS. We deal
265 ;;; with adding the names to the LEXENV-VARS for the conversion. The
266 ;;; result is added to the NEW-FUNCTIONALS in the *CURRENT-COMPONENT*
267 ;;; and linked to the component head and tail.
268 ;;;
269 ;;; We detect special bindings here, replacing the original VAR in the
270 ;;; lambda list with a temporary variable. We then pass a list of the
271 ;;; special vars to IR1-CONVERT-SPECIAL-BINDINGS, which actually emits
272 ;;; the special binding code.
273 ;;;
274 ;;; We ignore any ARG-INFO in the VARS, trusting that someone else is
275 ;;; dealing with &NONSENSE, except for &REST vars with DYNAMIC-EXTENT.
276 ;;;
277 ;;; AUX-VARS is a list of VAR structures for variables that are to be
278 ;;; sequentially bound. Each AUX-VAL is a form that is to be evaluated
279 ;;; to get the initial value for the corresponding AUX-VAR.
281 vars
282 &key
283 aux-vars
284 aux-vals
286 debug-name
288 post-binding-lexenv)
291 ;; We're about to try to put new blocks into *CURRENT-COMPONENT*.
296 :bind bind
297 :%source-name source-name
306 ;; just to check: This function should fail internal assertions if
307 ;; we didn't set up a valid debug name above.
308 ;;
309 ;; (In SBCL we try to make everything have a debug name, since we
310 ;; lack the omniscient perspective the original implementors used
311 ;; to decide which things didn't need one.)
319 ;; As far as I can see, LAMBDA-VAR-HOME should never have
320 ;; been set before. Let's make sure. -- WHN 2001-09-29
333 :lambda lambda
356 result-lvar body
358 post-binding-lexenv)))))
363 lambda))
365 ;;; Entry point CLAMBDAs have a special kind
372 entry)
374 ;;; Create the actual entry-point function for an optional entry
375 ;;; point. The lambda binds copies of each of the VARS, then calls FUN
376 ;;; with the argument VALS and the DEFAULTS. Presumably the VALS refer
377 ;;; to the VARS by name. The VALS are passed in the reverse order.
378 ;;;
379 ;;; If any of the copies of the vars are referenced more than once,
380 ;;; then we mark the corresponding var as EVER-USED to inhibit
381 ;;; "defined but not read" warnings for arguments that are only used
382 ;;; by default forms.
392 fvars))
405 arg-vars
406 ;; FIXME: Would be nice to
407 ;; share these names instead
408 ;; of consing up several
409 ;; identical ones. Oh well.
411 '&optional-processor
412 name)
417 fvars arg-vars)
418 fun))
420 ;;; This function deals with supplied-p vars in optional arguments. If
421 ;;; the there is no supplied-p arg, then we just call
422 ;;; IR1-CONVERT-HAIRY-ARGS on the remaining arguments, and generate a
423 ;;; optional entry that calls the result. If there is a supplied-p
424 ;;; var, then we add it into the default vars and throw a T into the
425 ;;; entry values. The resulting entry point function is returned.
427 entry-vars entry-vals
428 vars supplied-p-p body
429 aux-vars aux-vals
430 source-name debug-name
431 force post-binding-lexenv)
434 aux-vars aux-vals))
444 res
450 source-name debug-name
451 force post-binding-lexenv)
453 res
459 source-name debug-name
460 force post-binding-lexenv))))
462 ;; We want to delay converting the entry, but there exist
463 ;; problems: hidden references should not be established to
464 ;; lambdas of kind NIL should not have (otherwise the compiler
465 ;; might let-convert or delete them) and to variables.
468 supplied-p-p ; this entry will be of kind NIL
471 default-vars default-vals
473 name)
476 ;; DEFAULT can contain a reference to a
477 ;; to-be-optimized-away function/block/tag, so better to
478 ;; reduce code now (but we possibly lose syntax checking
479 ;; in an unreachable code).
483 default-vars default-vals
484 defaults
485 name)
486 res)))))))
488 ;;; Create the MORE-ENTRY function for the OPTIONAL-DISPATCH RES.
489 ;;; ENTRY-VARS and ENTRY-VALS describe the fixed arguments. REST is
490 ;;; the var for any &REST arg. KEYS is a list of the &KEY arg vars.
491 ;;;
492 ;;; The most interesting thing that we do is parse keywords. We create
493 ;;; a bunch of temporary variables to hold the result of the parse,
494 ;;; and then loop over the supplied arguments, setting the appropriate
495 ;;; temps for the supplied keyword. Note that it is significant that
496 ;;; we iterate over the keywords in reverse order --- this implements
497 ;;; the CL requirement that (when a keyword appears more than once)
498 ;;; the first value is used.
499 ;;;
500 ;;; If there is no supplied-p var, then we initialize the temp to the
501 ;;; default and just pass the temp into the main entry. Since
502 ;;; non-constant &KEY args are forcibly given a supplied-p var, we
503 ;;; know that the default is constant, and thus safe to evaluate out
504 ;;; of order.
505 ;;;
506 ;;; If there is a supplied-p var, then we create temps for both the
507 ;;; value and the supplied-p, and pass them into the main entry,
508 ;;; letting it worry about defaulting.
509 ;;;
510 ;;; We deal with :ALLOW-OTHER-KEYS by delaying unknown keyword errors
511 ;;; until we have scanned all the keywords.
619 ;;; This is called by IR1-CONVERT-HAIRY-ARGS when we run into a &REST
620 ;;; or &KEY arg. The arguments are similar to that function, but we
621 ;;; split off any &REST arg and pass it in separately. REST is the
622 ;;; &REST arg var, or NIL if there is no &REST arg. KEYS is a list of
623 ;;; the &KEY argument vars.
624 ;;;
625 ;;; When there are &KEY arguments, we introduce temporary gensym
626 ;;; variables to hold the values while keyword defaulting is in
627 ;;; progress to get the required sequential binding semantics.
628 ;;;
629 ;;; This gets interesting mainly when there are &KEY arguments with
630 ;;; supplied-p vars or non-constant defaults. In either case, pass in
631 ;;; a supplied-p var. If the default is non-constant, we introduce an
632 ;;; IF in the main entry that tests the supplied-p var and decides
633 ;;; whether to evaluate the default or not. In this case, the real
634 ;;; incoming value is NIL, so we must union NULL with the declared
635 ;;; type when computing the type for the main entry's argument.
637 rest more-context more-count keys supplied-p-p
638 body aux-vars aux-vals
639 source-name debug-name post-binding-lexenv)
642 aux-vars aux-vals))
662 "~A-DEFAULTING-TEMP"
694 :post-binding-lexenv post-binding-lexenv
701 name)
707 last-entry)
708 res)
710 last-entry)))
712 ;;; This function generates the entry point functions for the
713 ;;; OPTIONAL-DISPATCH RES. We accomplish this by recursion on the list
714 ;;; of arguments, analyzing the arglist on the way down and generating
715 ;;; entry points on the way up.
716 ;;;
717 ;;; DEFAULT-VARS is a reversed list of all the argument vars processed
718 ;;; so far, including supplied-p vars. DEFAULT-VALS is a list of the
719 ;;; names of the DEFAULT-VARS.
720 ;;;
721 ;;; ENTRY-VARS is a reversed list of processed argument vars,
722 ;;; excluding supplied-p vars. ENTRY-VALS is a list things that can be
723 ;;; evaluated to get the values for all the vars from the ENTRY-VARS.
724 ;;; It has the var name for each required or optional arg, and has T
725 ;;; for each supplied-p arg.
726 ;;;
727 ;;; VARS is a list of the LAMBDA-VAR structures for arguments that
728 ;;; haven't been processed yet. SUPPLIED-P-P is true if a supplied-p
729 ;;; argument has already been processed; only in this case are the
730 ;;; DEFAULT-XXX and ENTRY-XXX different.
731 ;;;
732 ;;; The result at each point is a lambda which should be called by the
733 ;;; above level to default the remaining arguments and evaluate the
734 ;;; body. We cause the body to be evaluated by converting it and
735 ;;; returning it as the result when the recursion bottoms out.
736 ;;;
737 ;;; Each level in the recursion also adds its entry point function to
738 ;;; the result OPTIONAL-DISPATCH. For most arguments, the defaulting
739 ;;; function and the entry point function will be the same, but when
740 ;;; SUPPLIED-P args are present they may be different.
741 ;;;
742 ;;; When we run into a &REST or &KEY arg, we punt out to
743 ;;; IR1-CONVERT-MORE, which finishes for us in this case.
745 entry-vars entry-vals
746 vars supplied-p-p body aux-vars
747 aux-vals
748 source-name debug-name
749 force post-binding-lexenv)
752 aux-vars aux-vals))
755 ;; Handle &KEY with no keys...
757 entry-vars entry-vals
758 nil nil nil vars supplied-p-p body aux-vars
759 aux-vals source-name debug-name
760 post-binding-lexenv)
764 :aux-vars aux-vars
765 :aux-vals aux-vals
766 :post-binding-lexenv post-binding-lexenv
774 name)
775 res)
776 fun)
778 fun)))
785 source-name debug-name
786 nil post-binding-lexenv)))
792 (:optional
794 res default-vars default-vals
795 entry-vars entry-vals vars supplied-p-p body
796 aux-vars aux-vals
797 source-name debug-name
798 force post-binding-lexenv)))
799 ;; See GENERATE-OPTIONAL-DEFAULT-ENTRY.
804 ep entry-vars entry-vals nil
806 ep)
807 res)
809 ep))
811 ep))
812 (:rest
814 entry-vars entry-vals
816 aux-vars aux-vals
817 source-name debug-name
818 post-binding-lexenv))
819 (:more-context
821 entry-vars entry-vals
823 body aux-vars aux-vals
824 source-name debug-name
825 post-binding-lexenv))
826 (:keyword
828 entry-vars entry-vals
829 nil nil nil vars supplied-p-p body aux-vars
830 aux-vals source-name debug-name
831 post-binding-lexenv)))))))
833 ;;; This function deals with the case where we have to make an
834 ;;; OPTIONAL-DISPATCH to represent a LAMBDA. We cons up the result and
835 ;;; call IR1-CONVERT-HAIRY-ARGS to do the work. When it is done, we
836 ;;; figure out the MIN-ARGS and MAX-ARGS.
838 &key
839 post-binding-lexenv
845 :allowp allowp
846 :keyp keyp
847 :%source-name source-name
848 :%debug-name debug-name
856 source-name debug-name nil post-binding-lexenv)
861 res))
863 ;;; Convert a LAMBDA form into a LAMBDA leaf or an OPTIONAL-DISPATCH leaf.
865 debug-name)
869 form))
872 'lambda
874 form))
877 "The lambda expression has a missing or non-list lambda list:~% ~S"
878 form))
890 ;; Using MAKE-SYMBOL would lead
891 ;; to recursive disaster.
894 forms))
896 forms
900 allow-other-keys
901 aux-vars aux-vals
902 :post-binding-lexenv post-binding-lexenv
903 :source-name source-name
906 :aux-vars aux-vars
907 :aux-vals aux-vals
908 :post-binding-lexenv post-binding-lexenv
909 :source-name source-name
913 res))))
915 ;;; helper for LAMBDA-like things, to massage them into a form
916 ;;; suitable for IR1-CONVERT-LAMBDA.
918 &key
920 debug-name)
924 :source-name source-name
929 :source-name source-name
944 res defined-fun-res))
945 res)
949 :source-name source-name
951 \f
952 ;;;; defining global functions
954 ;;; Convert FUN as a lambda in the null environment, but use the
955 ;;; current compilation policy. Note that FUN may be a
956 ;;; LAMBDA-WITH-LEXENV, so we may have to augment the environment to
957 ;;; reflect the state at the definition site.
959 &key
961 debug-name
962 system-lambda)
974 macros)
978 :source-name source-name
981 ;;; Get a DEFINED-FUN object for a function we are about to define. If
982 ;;; the function has been forward referenced, then substitute for the
983 ;;; previous references.
992 :%source-name name
998 ;; If *FREE-FUNS* has a previously converted definition
999 ;; for this name, then blow it away and try again.
1005 ;;; Check a new global function definition for consistency with
1006 ;;; previous declaration or definition, and assert argument/result
1007 ;;; types if appropriate. This assertion is suppressed by the
1008 ;;; EXPLICIT-CHECK attribute, which is specified on functions that
1009 ;;; check their argument types as a consequence of type dispatching.
1010 ;;; This avoids redundant checks such as NUMBERP on the args to +, etc.
1016 fun type
1017 ;; KLUDGE: Common Lisp is such a dynamic language that in general
1018 ;; all we can do here in general is issue a STYLE-WARNING. It
1019 ;; would be nice to issue a full WARNING in the special case of
1020 ;; of type mismatches within a compilation unit (as in section
1021 ;; 3.2.2.3 of the spec) but at least as of sbcl-0.6.11, we don't
1022 ;; keep track of whether the mismatched data came from the same
1023 ;; compilation unit, so we can't do that. -- WHN 2001-02-11
1028 :really-assert
1032 explicit-check))))
1034 "previous declaration"
1037 ;;; Used for global inline expansion. Earlier something like this was
1038 ;;; used by %DEFUN too. FIXME: And now it's probably worth rethinking
1039 ;;; whether this function is a good idea at all.
1041 ;; Unless a :INLINE function, we temporarily clobber the inline
1042 ;; expansion. This prevents recursive inline expansion of
1043 ;; opportunistic pseudo-inlines.
1047 :source-name name
1048 ;; prevent instrumentation of
1049 ;; known function expansions
1054 ;; substitute for any old references
1061 fun))
1063 ;;; the even-at-compile-time part of DEFUN
1064 ;;;
1065 ;;; The INLINE-EXPANSION is a LAMBDA-WITH-LEXENV, or NIL if there is
1066 ;;; no inline expansion.
1070 ;; better be in the compiler
1083 lambda-with-lexenv)
1086 lambda-with-lexenv)))
1090 ;; old CMU CL comment:
1091 ;; If there is a type from a previous definition, blast it,
1092 ;; since it is obsolete.
1096 ;; FIXME: If this is a block compilation thing, shouldn't
1097 ;; we be setting the type to the full derived type for the
1098 ;; definition, instead of this most general function type?
1103 \f
1104 ;;; Entry point utilities
1106 ;;; Return a function for the Nth entry point.