1 /* $OpenBSD: for.c,v 1.48 2023/09/04 11:35:11 espie Exp $ */
2 /* $NetBSD: for.c,v 1.4 1996/11/06 17:59:05 christos Exp $ */
3
4 /*
5 * Copyright (c) 1999 Marc Espie.
6 *
7 * Extensive code modifications for the OpenBSD project.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD
22 * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 /*
32 * Copyright (c) 1992, The Regents of the University of California.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 * 3. Neither the name of the University nor the names of its contributors
44 * may be used to endorse or promote products derived from this software
45 * without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57 * SUCH DAMAGE.
58 */
59
60 #include <assert.h>
61 #include <ctype.h>
62 #include <stddef.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include "defines.h"
67 #include "buf.h"
68 #include "for.h"
69 #include "lst.h"
70 #include "error.h"
71 #include "var.h"
72 #include "lowparse.h"
73 #include "str.h"
74 #include "memory.h"
75
76 /*
77 * For statements are of the form:
78 *
79 * .for <variable> [variable...] in <varlist>
80 * ...
81 * .endfor
82 *
83 * The trick is to look for the matching .end inside .for loops.
84 * To do that, we keep track of the nesting level of .for loops
85 * and matching .endfor statements, accumulating all statements between
86 * the initial .for loop and the matching .endfor,
87 * then we evaluate the .for loop for each variable in the varlist.
88 */
89
90 /* State of a for loop. */
91 struct For_ {
92 char *text; /* Unexpanded text */
93 LIST vars; /* List of variables */
94 LstNode var; /* Current var */
95 int nvars; /* Total number of vars */
96 LIST lst; /* List of items */
97 size_t guess; /* Estimated expansion size */
98 BUFFER buf; /* Accumulating text */
99 unsigned long lineno; /* Line number at start of loop */
100 unsigned long level; /* Nesting level */
101 bool freeold;
102 };
103
104 /* ForExec(value, handle);
105 * Expands next variable in loop sequence described by handle to value. */
106 static void ForExec(void *, void *);
107
108 /* n = build_words_list(lst, s);
109 * Cuts string into words, pushes words into list, in reverse order,
110 * because Parse_FromString works as a stack.
111 * Returns the number of words. */
112 static unsigned long build_words_list(Lst, const char *);
113
114 static unsigned long
build_words_list(Lst lst,const char * s)115 build_words_list(Lst lst, const char *s)
116 {
117 const char *end, *wrd;
118 unsigned long n;
119
120 n = 0;
121 end = s;
122
123 while ((wrd = iterate_words(&end)) != NULL) {
124 Lst_AtFront(lst, escape_dupi(wrd, end, "\"'"));
125 n++;
126 }
127 return n;
128 }
129
130 For *
For_Eval(const char * line)131 For_Eval(const char *line)
132 {
133 const char *ptr = line;
134 const char *wrd;
135 char *sub;
136 const char *endVar;
137 For *arg;
138 unsigned long n;
139
140 while (ISSPACE(*ptr))
141 ptr++;
142
143 /* Parse loop. */
144
145 arg = emalloc(sizeof(*arg));
146 arg->nvars = 0;
147 Lst_Init(&arg->vars);
148
149 for (;;) {
150 /* Grab the variables. */
151 for (wrd = ptr; *ptr && !ISSPACE(*ptr); ptr++)
152 continue;
153 if (ptr - wrd == 0) {
154 Parse_Error(PARSE_FATAL, "Syntax error in for");
155 return 0;
156 }
157 endVar = ptr;
158 if (*ptr) {
159 ptr++;
160 while (ISSPACE(*ptr))
161 ptr++;
162 }
163 /* End of variable list ? */
164 if (endVar - wrd == 2 && wrd[0] == 'i' && wrd[1] == 'n')
165 break;
166 Lst_AtEnd(&arg->vars, Var_NewLoopVar(wrd, endVar));
167 arg->nvars++;
168 }
169 if (arg->nvars == 0) {
170 Parse_Error(PARSE_FATAL, "Missing variable in for");
171 return 0;
172 }
173
174 /* Make a list with the remaining words. */
175 sub = Var_Subst(ptr, NULL, false);
176 if (DEBUG(FOR)) {
177 LstNode ln;
178 (void)fprintf(stderr, "For: Iterator ");
179 for (ln = Lst_First(&arg->vars); ln != NULL; ln = Lst_Adv(ln))
180 (void)fprintf(stderr, "%s ",
181 Var_LoopVarName(Lst_Datum(ln)));
182 (void)fprintf(stderr, "List %s\n", sub);
183 }
184
185 Lst_Init(&arg->lst);
186 n = build_words_list(&arg->lst, sub);
187 free(sub);
188 if (arg->nvars != 1 && n % arg->nvars != 0) {
189 LstNode ln;
190
191 Parse_Error(PARSE_FATAL, "Wrong number of items in for loop");
192 (void)fprintf(stderr, "%lu items for %d variables:",
193 n, arg->nvars);
194 for (ln = Lst_First(&arg->lst); ln != NULL; ln = Lst_Adv(ln)) {
195 char *p = Lst_Datum(ln);
196
197 (void)fprintf(stderr, " %s", p);
198 }
199 (void)fprintf(stderr, "\n");
200 return 0;
201 }
202 arg->lineno = Parse_Getlineno();
203 arg->level = 1;
204 Buf_Init(&arg->buf, 0);
205
206 return arg;
207 }
208
209
210 bool
For_Accumulate(For * arg,const char * line)211 For_Accumulate(For *arg, const char *line)
212 {
213 const char *ptr = line;
214
215 assert(arg->level > 0);
216
217 if (*ptr == '.') {
218
219 for (ptr++; ISSPACE(*ptr); ptr++)
220 continue;
221
222 if (strncmp(ptr, "endfor", 6) == 0 &&
223 (ISSPACE(ptr[6]) || !ptr[6])) {
224 if (DEBUG(FOR))
225 (void)fprintf(stderr, "For: end for %lu\n",
226 arg->level);
227 /* If matching endfor, don't add line to buffer. */
228 if (--arg->level == 0)
229 return false;
230 }
231 else if (strncmp(ptr, "for", 3) == 0 &&
232 ISSPACE(ptr[3])) {
233 arg->level++;
234 if (DEBUG(FOR))
235 (void)fprintf(stderr, "For: new loop %lu\n",
236 arg->level);
237 }
238 }
239 Buf_AddString(&arg->buf, line);
240 Buf_AddChar(&arg->buf, '\n');
241 return true;
242 }
243
244
245 #define GUESS_EXPANSION 32
246 static void
ForExec(void * valuep,void * argp)247 ForExec(void *valuep, void *argp)
248 {
249 char *value = valuep;
250 For *arg = argp;
251 BUFFER buf;
252
253 /* Parse_FromString pushes stuff back, so we need to go over vars in
254 reverse. */
255 if (arg->var == NULL) {
256 arg->var = Lst_Last(&arg->vars);
257 arg->text = Buf_Retrieve(&arg->buf);
258 arg->freeold = false;
259 }
260
261 if (DEBUG(FOR))
262 (void)fprintf(stderr, "--- %s = %s\n",
263 Var_LoopVarName(Lst_Datum(arg->var)), value);
264 Buf_Init(&buf, arg->guess);
265 Var_SubstVar(&buf, arg->text, Lst_Datum(arg->var), value);
266 if (arg->freeold)
267 free(arg->text);
268 arg->text = Buf_Retrieve(&buf);
269 arg->freeold = true;
270 arg->var = Lst_Rev(arg->var);
271 if (arg->var == NULL)
272 Parse_FromString(arg->text, arg->lineno);
273 }
274
275
276 void
For_Run(For * arg)277 For_Run(For *arg)
278 {
279 arg->text = Buf_Retrieve(&arg->buf);
280 arg->guess = Buf_Size(&arg->buf) + GUESS_EXPANSION;
281
282 arg->var = NULL;
283 Lst_ForEach(&arg->lst, ForExec, arg);
284 Buf_Destroy(&arg->buf);
285 Lst_Destroy(&arg->vars, (SimpleProc)Var_DeleteLoopVar);
286 Lst_Destroy(&arg->lst, (SimpleProc)free);
287 free(arg);
288 }
289