This file is indexed.

/usr/share/common-lisp/source/regex/gen.lisp is in cl-regex 1-4.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
;;; -*- Mode: LISP; Syntax: COMMON-LISP; Package: REGEX; Base: 10 -*-

(in-package :REGEX)

;;;
;;; Pass 5 - Generate list of CPS instructions
;;;
; Generate a flattened list of instructions, with continuation
; targets, and (init) and (success) in the proper places...

(defun gen-instr-list (tree)
  (let* ((*instrs*)
	 (*next-instr* 0))
    (declare (special *instrs* *next-instr*))
    (let* ((success-instr (alloc-instr))
           (start-instr (emit-instr tree success-instr)))
      (add-instr success-instr '(success t))
      (values start-instr 
              (sort *instrs* #'< :key #'first)))))

(defun add-instr (statenum instr)
  (declare (special *instrs*))
  (push (cons statenum instr) *instrs*)
  statenum)

(defun alloc-instr ()
  (declare (special *next-instr*))
  (let ((instr *next-instr*))
    (incf *next-instr*)
    instr))



; similar to old compile-state-machine
(defun emit-instr (node next)
  (cond
   ((null node) next)
   ((eq (first node) 'char)
    (add-instr (alloc-instr) `(char ,(second node) ,next)))
   ((eq (first node) 'string)
    (add-instr (alloc-instr) `(string ,(second node) ,next)))
   ((classseq-node-p node)
    (add-instr (alloc-instr) `(classseq ,(classseq-node-seq node) ,next)))
   ((backmatch-node-p node)
    (add-instr (alloc-instr) `(backmatch ,(backmatch-node-regnum node) ,next)))
   ((seq-node-p node)
    (emit-sequence (seq-node-children node) next))
   ;; kleene-nodes have been optimized to specialized instructions
   ((eq (first node) 'str-greedy-kleene)
    (add-instr (alloc-instr)
               `(str-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'char-greedy-kleene)
    (add-instr (alloc-instr)
               `(char-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'not-char-greedy-kleene)
    (add-instr (alloc-instr)
               `(not-char-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'cclass-2-greedy-kleene)
    (add-instr (alloc-instr)
               `(cclass-2-greedy-kleene ,(second node) ,(third node) ,next)))
   ((eq (first node) 'not-cclass-2-greedy-kleene)
    (add-instr (alloc-instr)
               `(not-cclass-2-greedy-kleene ,(second node) ,(third node) ,next)))
   ((eq (first node) 'cclass-greedy-kleene)
    (add-instr (alloc-instr) `(cclass-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'not-cclass-greedy-kleene)
    (add-instr (alloc-instr) `(not-cclass-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'specclass-greedy-kleene)
    (add-instr (alloc-instr) `(specclass-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'not-specclass-greedy-kleene)
    (add-instr (alloc-instr) `(not-specclass-greedy-kleene ,(second node) ,next)))
   ((eq (first node) 'greedy-kleene-no-termcheck)
    (emit-greedy-kleene-no-termcheck (second node) next))
   ((eq (first node) 'greedy-kleene-simple-termcheck)
    (emit-greedy-kleene-simple-termcheck (second node) next))
   ((eq (first node) 'greedy-kleene-full-termcheck)
    (emit-greedy-kleene-full-termcheck (second node) next))
   ((eq (first node) 'ngkleene-no-termcheck)
    (emit-ngkleene-no-termcheck (second node) next))
   ((eq (first node) 'ngkleene-simple-termcheck)
    (emit-ngkleene-simple-termcheck (second node) next))
   ((eq (first node) 'ngkleene-full-termcheck)
    (emit-ngkleene-full-termcheck (second node) next))
   ;; pkleene-nodes are long since converted to opt and kleene nodes
   ;; optional nodes are long since converted to alt nodes
   ;; range-nodes are long since gone...
   ((alt-node-p node)
    (emit-alt (alt-node-children node) next))
   ((casealt-node-p node)
    (emit-casealt (casealt-node-children node) next))
   ((start-anchor-node-p node)
    (add-instr (alloc-instr) `(startanchor ,next)))
   ((end-anchor-node-p node)
    (add-instr (alloc-instr) `(endanchor ,next)))
   ;; register-nodes are long since gone, converted to regstart/regend
   ((eq (first node) 'right-rstart)
    (add-instr (alloc-instr)
               `(right-rstart ,(second node) ,next)))
   ((eq (first node) 'left-rstart)
    (add-instr (alloc-instr)
               `(left-rstart ,(second node) ,next)))
   ((regend-node-p node)
    (add-instr (alloc-instr) `(rend ,(regend-node-regnum node) ,next)))
   ;; charclass-nodes are long since converted to specialized instr nodes
   ((eq (first node) 'cclass-2)
    (add-instr (alloc-instr)
               `(cclass-2 ,(second node) ,(third node) ,next)))
   ((eq (first node) 'cclass)
    (add-instr (alloc-instr)
               `(cclass ,(second node) ,next)))
   ((eq (first node) 'not-char)
    (add-instr (alloc-instr)
               `(not-char ,(second node) ,next)))
   ((eq (first node) 'not-cclass-2)
    (add-instr (alloc-instr)
               `(not-cclass-2 ,(second node) ,(third node) ,next)))
   ((eq (first node) 'not-cclass)
    (add-instr (alloc-instr) `(not-cclass ,(second node) ,next)))
   ;; specclass-nodes are long since gone, converted to specialized instr nodes
   ((eq (first node) 'specclass)
    (add-instr (alloc-instr) `(specclass ,(second node) ,next)))
   ((eq (first node) 'not-specclass)
    (add-instr (alloc-instr) `(not-specclass ,(second node) ,next)))
   ((any-node-p node)
    (add-instr (alloc-instr) `(any ,next)))
   ((startword-node-p node)
    (add-instr (alloc-instr) `(startword ,next)))
   ((endword-node-p node)
    (add-instr (alloc-instr) `(endword ,next)))
   ((lookahead-node-p node)
    (emit-lookahead (second node) next))
   ((nlookahead-node-p node)
    (emit-nlookahead (second node) next))
   ((hook-node-p node)
    (add-instr (alloc-instr)
               `(hook ,(hook-node-function node) ,next)))
   ((success-node-p node)
    (add-instr (alloc-instr)
               `(success ,(success-node-rc node) ,next)))
   (t ;; once we're done, this should throw the :invalid-parse-tree tag
      (throw 'regex-parse-error
             (list "codegen: Unhandled intermediate node ~S" node)))))

(defun emit-sequence (children next)
  (cond ((null children) next)
        (t (emit-instr (first children)
                       (emit-sequence (rest children) next)))))

(defun emit-lookahead (child-node next)
  (let* ((childsuccess-instr-num (alloc-instr))
         (child-instr-num (emit-instr child-node childsuccess-instr-num)))
    (add-instr childsuccess-instr-num '(success t))
    (add-instr (alloc-instr)
               `(lookahead ,child-instr-num ,next)) ))

(defun emit-nlookahead (child-node next)
  (let* ((childsuccess-instr-num (alloc-instr))
         (child-instr-num (emit-instr child-node childsuccess-instr-num)))
    (add-instr childsuccess-instr-num '(success t))
    (add-instr (alloc-instr)
               `(nlookahead ,child-instr-num ,next)) ))

(defun emit-greedy-kleene-no-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-no-termcheck ,body-instr-num ,next))))

(defun emit-greedy-kleene-simple-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-simple-termcheck-1 ,body-instr-num ,next))))

(defun emit-greedy-kleene-full-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-full-termcheck ,body-instr-num ,next))))

(defun emit-ngkleene-no-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-no-termcheck ,next ,body-instr-num))))

(defun emit-ngkleene-simple-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-simple-termcheck-2 ,next ,body-instr-num))))

(defun emit-ngkleene-full-termcheck (child-node next)
  (let* ((loop-instr-num (alloc-instr))
         (body-instr-num (emit-instr child-node loop-instr-num)))
    (add-instr loop-instr-num
               `(alt-2-full-termcheck ,next ,body-instr-num))))

(defun emit-alt (child-nodes next)
  (let* ((alt-instr-num (alloc-instr))
         (child-instr-nums (mapcar (lambda (child-node)
                                     (emit-instr child-node next))
                                   child-nodes))
         (num-children (length child-nodes)))
    (cond ((< num-children 2)
           (error "Too few child nodes for alt ~S" child-nodes))
          ((= (length child-nodes) 2)
           (add-instr alt-instr-num
                      `(alt-2-no-termcheck ,@child-instr-nums)))
          (t (add-instr alt-instr-num
                        `(alt-no-termcheck ,child-instr-nums))))))

;; The arms may be replicated many times, so we need to be careful to re-use
;; them when necessary
(defun emit-casealt (child-nodes next)
  (let* ((alt-instr-num (alloc-instr))
         (arm-reuse-cache (make-hash-table :test 'equalp))
         (child-instr-branches
          (mapcar (lambda (arm)
                    (let* ((guard (first arm))
                           (consequent-node (second arm))
                           (prev-lbl (gethash consequent-node arm-reuse-cache)))
                      (if prev-lbl
                          (list guard prev-lbl)
                        (list guard (setf (gethash consequent-node arm-reuse-cache)
                                          (emit-instr consequent-node next))))))
                  child-nodes))
         (num-children (length child-nodes)))
    (cond ((< num-children 2)
           (error "Too few child nodes for alt ~S" child-nodes))
          (t
           (add-instr alt-instr-num
                      `(casealt ,child-instr-branches))))))