1 ;;;; the representation of a lexical environment
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
14 #!-sb-fluid (declaim (inline internal-make-lexenv)) ; only called in one place
16 ;;; The LEXENV represents the lexical environment used for IR1 conversion.
17 ;;; (This is also what shows up as an ENVIRONMENT value in macroexpansion.)
18 #!-sb-fluid (declaim (inline internal-make-lexenv)) ; only called in one place
20 (:constructor make-null-lexenv ())
21 (:constructor make-null-interactive-lexenv
22 (&aux (policy (list '(safety . 3)
23 '(compilation-speed . 2)
27 '(inhibit-warnings . 1)))))
28 (:constructor internal-make-lexenv
29 (funs vars blocks tags type-restrictions
30 lambda cleanup policy)))
31 ;; an alist of (NAME . WHAT), where WHAT is either a FUNCTIONAL (a
32 ;; local function), a DEFINED-FUN, representing an
33 ;; INLINE/NOTINLINE declaration, or a list (MACRO . <function>) (a
34 ;; local macro, with the specifier expander). Note that NAME may be
35 ;; a (SETF <name>) list, not necessarily a single symbol.
37 ;; an alist translating variable names to LEAF structures. A special
38 ;; binding is indicated by a :SPECIAL GLOBAL-VAR leaf. Each special
39 ;; binding within the code gets a distinct leaf structure, as does
40 ;; the current "global" value on entry to the code compiled.
41 ;; (locally (special ...)) is handled by adding the most recent
42 ;; special binding to the front of the list.
44 ;; If the CDR is (MACRO . <exp>), then <exp> is the expansion of a
47 ;; BLOCKS and TAGS are alists from block and go-tag names to 2-lists
48 ;; of the form (<entry> <continuation>), where <continuation> is the
49 ;; continuation to exit to, and <entry> is the corresponding ENTRY node.
50 (blocks nil :type list)
52 ;; an alist (THING . CTYPE) which is used to keep track of
53 ;; "pervasive" type declarations. When THING is a leaf, this is for
54 ;; type declarations that pertain to the type in a syntactic extent
55 ;; which does not correspond to a binding of the affected name. When
56 ;; THING is a continuation, this is used to track the innermost THE
58 (type-restrictions nil :type list)
59 ;; the lexically enclosing lambda, if any
61 ;; FIXME: This should be :TYPE (OR CLAMBDA NULL), but it was too hard
62 ;; to get CLAMBDA defined in time for the cross-compiler.
64 ;; the lexically enclosing cleanup, or NIL if none enclosing within Lambda
66 ;; the current OPTIMIZE policy
67 (policy *policy* :type policy))
69 ;;; support for the idiom (in MACROEXPAND and elsewhere) that NIL is
70 ;;; to be taken as a null lexical environment
71 (defun coerce-to-lexenv (x)
73 (null (make-null-lexenv))
76 ;;; Is it safe to just grab the lambda expression LAMBDA in isolation,
77 ;;; ignoring the LEXENV?
79 ;;; Note: The corresponding CMU CL code did something hairier so that
80 ;;; it could save inline definitions of DEFUNs in nontrivial lexical
81 ;;; environments. If it's ever important to try to do that, take a
82 ;;; look at the old CMU CL #'INLINE-SYNTACTIC-CLOSURE.
83 (defun lambda-independent-of-lexenv-p (lambda lexenv)
84 (declare (type list lambda) (type lexenv lexenv))
85 (aver (eql (first lambda) 'lambda)) ; basic sanity check
86 ;; This is a trivial implementation that just makes sure that LEXENV
87 ;; doesn't have anything interesting in it. A more sophisticated
88 ;; implementation could skip things in LEXENV which aren't captured
89 ;; by LAMBDA, but this implementation doesn't try.
90 (and (null (lexenv-blocks lexenv))
91 (null (lexenv-tags lexenv))
92 (null (lexenv-vars lexenv))
93 (null (lexenv-funs lexenv))))