1 /*	$OpenPackages$ */
2 /*	$OpenBSD: for.c,v 1.31 2007/03/20 03:50:39 tedu Exp $	*/
3 /*	$NetBSD: for.c,v 1.4 1996/11/06 17:59:05 christos Exp $ */
4 
5 /*
6  * Copyright (c) 1999 Marc Espie.
7  *
8  * Extensive code modifications for the OpenBSD project.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
23  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1992, The Regents of the University of California.
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  */
60 
61 #include <assert.h>
62 #include <ctype.h>
63 #include <stddef.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include "config.h"
68 #include "defines.h"
69 #include "buf.h"
70 #include "for.h"
71 #include "lst.h"
72 #include "error.h"
73 #include "var.h"
74 #include "lowparse.h"
75 #include "str.h"
76 #include "memory.h"
77 
78 /*
79  * For statements are of the form:
80  *
81  * .for <variable> [variable...] in <varlist>
82  * ...
83  * .endfor
84  *
85  * The trick is to look for the matching .end inside .for loops.
86  * To do that, we keep track of the nesting level of .for loops
87  * and matching .endfor statements, accumulating all statements between
88  * the initial .for loop and the matching .endfor,
89  * then we evaluate the .for loop for each variable in the varlist.
90  */
91 
92 /* State of a for loop.  */
93 struct For_ {
94     char		*text;		/* Unexpanded text		*/
95     LIST		vars;		/* List of variables		*/
96     LstNode		var;		/* Current var			*/
97     int			nvars;		/* Total number of vars		*/
98     LIST		lst;		/* List of items		*/
99     size_t		guess;		/* Estimated expansion size	*/
100     BUFFER		buf;		/* Accumulating text		*/
101     unsigned long	lineno; 	/* Line number at start of loop */
102     unsigned long	level;		/* Nesting level		*/
103     bool		freeold;
104 };
105 
106 /* ForExec(value, handle);
107  *	Expands next variable in loop sequence described by handle to value. */
108 static void ForExec(void *, void *);
109 
110 /* n = build_words_list(lst, s);
111  *	Cuts string into words, pushes words into list, in reverse order,
112  *	because Parse_FromString works as a stack.
113  *	Returns the number of words.  */
114 static unsigned long build_words_list(Lst, const char *);
115 
116 static unsigned long
build_words_list(Lst lst,const char * s)117 build_words_list(Lst lst, const char *s)
118 {
119     const char *end, *wrd;
120     unsigned long n;
121 
122     n = 0;
123     end = s;
124 
125     while ((wrd = iterate_words(&end)) != NULL) {
126 	Lst_AtFront(lst, escape_dupi(wrd, end, "\"'"));
127 	n++;
128     }
129     return n;
130 }
131 
132 For *
For_Eval(const char * line)133 For_Eval(const char *line)
134 {
135     const char	*ptr = line;
136     const char	*wrd;
137     char	*sub;
138     const char	*endVar;
139     For 	*arg;
140     unsigned long n;
141 
142     while (isspace(*ptr))
143 	ptr++;
144 
145     /* Parse loop.  */
146 
147     arg = emalloc(sizeof(*arg));
148     arg->nvars = 0;
149     Lst_Init(&arg->vars);
150 
151     for (;;) {
152 	/* Grab the variables.  */
153 	for (wrd = ptr; *ptr && !isspace(*ptr); ptr++)
154 	    continue;
155 	if (ptr - wrd == 0) {
156 	    Parse_Error(PARSE_FATAL, "Syntax error in for");
157 	    return 0;
158 	}
159 	endVar = ptr++;
160 	while (isspace(*ptr))
161 	    ptr++;
162 	/* End of variable list ? */
163 	if (endVar - wrd == 2 && wrd[0] == 'i' && wrd[1] == 'n')
164 	    break;
165 	Lst_AtEnd(&arg->vars, Str_dupi(wrd, endVar));
166 	arg->nvars++;
167     }
168     if (arg->nvars == 0) {
169 	Parse_Error(PARSE_FATAL, "Missing variable in for");
170 	return 0;
171     }
172 
173     /* Make a list with the remaining words.  */
174     sub = Var_Subst(ptr, NULL, false);
175     if (DEBUG(FOR)) {
176     	LstNode ln;
177 	(void)fprintf(stderr, "For: Iterator ");
178 	for (ln = Lst_First(&arg->vars); ln != NULL; ln = Lst_Adv(ln))
179 		(void)fprintf(stderr, "%s ", (char *)Lst_Datum(ln));
180 	(void)fprintf(stderr, "List %s\n", sub);
181     }
182 
183     Lst_Init(&arg->lst);
184     n = build_words_list(&arg->lst, sub);
185     free(sub);
186     if (arg->nvars != 1 && n % arg->nvars != 0) {
187 	Parse_Error(PARSE_FATAL, "Wrong number of items in for loop");
188     	return 0;
189     }
190     arg->lineno = Parse_Getlineno();
191     arg->level = 1;
192     Buf_Init(&arg->buf, 0);
193 
194     return arg;
195 }
196 
197 
198 bool
For_Accumulate(For * arg,const char * line)199 For_Accumulate(For *arg, const char *line)
200 {
201     const char	    *ptr = line;
202 
203     assert(arg->level > 0);
204 
205     if (*ptr == '.') {
206 
207 	for (ptr++; isspace(*ptr); ptr++)
208 	    continue;
209 
210 	if (strncmp(ptr, "endfor", 6) == 0 &&
211 	    (isspace(ptr[6]) || !ptr[6])) {
212 	    if (DEBUG(FOR))
213 		(void)fprintf(stderr, "For: end for %lu\n", arg->level);
214 	    /* If matching endfor, don't add line to buffer.  */
215 	    if (--arg->level == 0)
216 		return false;
217 	}
218 	else if (strncmp(ptr, "for", 3) == 0 &&
219 		 isspace(ptr[3])) {
220 	    arg->level++;
221 	    if (DEBUG(FOR))
222 		(void)fprintf(stderr, "For: new loop %lu\n", arg->level);
223 	}
224     }
225     Buf_AddString(&arg->buf, line);
226     Buf_AddChar(&arg->buf, '\n');
227     return true;
228 }
229 
230 
231 #define GUESS_EXPANSION 32
232 static void
ForExec(void * valuep,void * argp)233 ForExec(void *valuep, void *argp)
234 {
235     char *value = (char *)valuep;
236     For *arg = (For *)argp;
237     BUFFER buf;
238 
239     /* Parse_FromString pushes stuff back, so we need to go over vars in
240        reverse.  */
241     if (arg->var == NULL) {
242     	arg->var = Lst_Last(&arg->vars);
243 	arg->text = Buf_Retrieve(&arg->buf);
244 	arg->freeold = false;
245     }
246 
247     if (DEBUG(FOR))
248 	(void)fprintf(stderr, "--- %s = %s\n", (char *)Lst_Datum(arg->var),
249 	    value);
250     Buf_Init(&buf, arg->guess);
251     Var_SubstVar(&buf, arg->text, Lst_Datum(arg->var), value);
252     if (arg->freeold)
253     	free(arg->text);
254     arg->text = Buf_Retrieve(&buf);
255     arg->freeold = true;
256     arg->var = Lst_Rev(arg->var);
257     if (arg->var == NULL)
258 	Parse_FromString(arg->text, arg->lineno);
259 }
260 
261 
262 void
For_Run(For * arg)263 For_Run(For *arg)
264 {
265     arg->text = Buf_Retrieve(&arg->buf);
266     arg->guess = Buf_Size(&arg->buf) + GUESS_EXPANSION;
267 
268     arg->var = NULL;
269     Lst_ForEach(&arg->lst, ForExec, arg);
270     Buf_Destroy(&arg->buf);
271     Lst_Destroy(&arg->vars, (SimpleProc)free);
272     Lst_Destroy(&arg->lst, (SimpleProc)free);
273     free(arg);
274 }
275