xref: /minix3/external/bsd/flex/dist/buf.c (revision 0b98e8aad89f2bd4ba80b523d73cf29e9dd82ce1)
1 /*	$NetBSD: buf.c,v 1.2 2013/04/06 14:27:52 christos Exp $	*/
2 
3 /* flex - tool to generate fast lexical analyzers */
4 
5 /*  Copyright (c) 1990 The Regents of the University of California. */
6 /*  All rights reserved. */
7 
8 /*  This code is derived from software contributed to Berkeley by */
9 /*  Vern Paxson. */
10 
11 /*  The United States Government has rights in this work pursuant */
12 /*  to contract no. DE-AC03-76SF00098 between the United States */
13 /*  Department of Energy and the University of California. */
14 
15 /*  This file is part of flex. */
16 
17 /*  Redistribution and use in source and binary forms, with or without */
18 /*  modification, are permitted provided that the following conditions */
19 /*  are met: */
20 
21 /*  1. Redistributions of source code must retain the above copyright */
22 /*     notice, this list of conditions and the following disclaimer. */
23 /*  2. Redistributions in binary form must reproduce the above copyright */
24 /*     notice, this list of conditions and the following disclaimer in the */
25 /*     documentation and/or other materials provided with the distribution. */
26 
27 /*  Neither the name of the University nor the names of its contributors */
28 /*  may be used to endorse or promote products derived from this software */
29 /*  without specific prior written permission. */
30 
31 /*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
32 /*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
33 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
34 /*  PURPOSE. */
35 
36 #include "flexdef.h"
37 
38 /* Take note: The buffer object is sometimes used as a String buffer (one
39  * continuous string), and sometimes used as a list of strings, usually line by
40  * line.
41  *
42  * The type is specified in buf_init by the elt_size. If the elt_size is
43  * sizeof(char), then the buffer should be treated as string buffer. If the
44  * elt_size is sizeof(char*), then the buffer should be treated as a list of
45  * strings.
46  *
47  * Certain functions are only appropriate for one type or the other.
48  */
49 
50 /* global buffers. */
51 struct Buf userdef_buf;		/**< for user #definitions triggered by cmd-line. */
52 struct Buf defs_buf;		/**< for #define's autogenerated. List of strings. */
53 struct Buf yydmap_buf;		/**< string buffer to hold yydmap elements */
54 struct Buf m4defs_buf;          /**< m4 definitions. List of strings. */
55 struct Buf top_buf;             /**< contains %top code. String buffer. */
56 
57 struct Buf *buf_print_strings(struct Buf * buf, FILE* out)
58 {
59     int i;
60 
61     if(!buf || !out)
62         return buf;
63 
64     for (i=0; i < buf->nelts; i++){
65         const char * s = ((char**)buf->elts)[i];
66         if(s)
67             fprintf(out, "%s", s);
68     }
69     return buf;
70 }
71 
72 /* Append a "%s" formatted string to a string buffer */
73 struct Buf *buf_prints (struct Buf *buf, const char *fmt, const char *s)
74 {
75 	char   *t;
76         size_t tsz;
77 
78 	t = flex_alloc (tsz = strlen (fmt) + strlen (s) + 1);
79 	if (!t)
80 	    flexfatal (_("Allocation of buffer to print string failed"));
81 	snprintf (t, tsz, fmt, s);
82 	buf = buf_strappend (buf, t);
83 	flex_free (t);
84 	return buf;
85 }
86 
87 /** Append a line directive to the string buffer.
88  * @param buf A string buffer.
89  * @param filename file name
90  * @param lineno line number
91  * @return buf
92  */
93 struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
94 {
95     char *dst, *t;
96     const char *src;
97 
98     t = flex_alloc (strlen ("#line \"\"\n")          +   /* constant parts */
99                     2 * strlen (filename)            +   /* filename with possibly all backslashes escaped */
100                     (int) (1 + log10 (abs (lineno))) +   /* line number */
101                     1);                                  /* NUL */
102     if (!t)
103       flexfatal (_("Allocation of buffer for line directive failed"));
104     for (dst = t + sprintf (t, "#line %d \"", lineno), src = filename; *src; *dst++ = *src++)
105       if (*src == '\\')   /* escape backslashes */
106         *dst++ = '\\';
107     *dst++ = '"';
108     *dst++ = '\n';
109     *dst   = '\0';
110     buf = buf_strappend (buf, t);
111     flex_free (t);
112     return buf;
113 }
114 
115 
116 /** Append the contents of @a src to @a dest.
117  * @param @a dest the destination buffer
118  * @param @a dest the source buffer
119  * @return @a dest
120  */
121 struct Buf *buf_concat(struct Buf* dest, const struct Buf* src)
122 {
123     buf_append(dest, src->elts, src->nelts);
124     return dest;
125 }
126 
127 
128 /* Appends n characters in str to buf. */
129 struct Buf *buf_strnappend (buf, str, n)
130      struct Buf *buf;
131      const char *str;
132      int n;
133 {
134 	buf_append (buf, str, n + 1);
135 
136 	/* "undo" the '\0' character that buf_append() already copied. */
137 	buf->nelts--;
138 
139 	return buf;
140 }
141 
142 /* Appends characters in str to buf. */
143 struct Buf *buf_strappend (buf, str)
144      struct Buf *buf;
145      const char *str;
146 {
147 	return buf_strnappend (buf, str, strlen (str));
148 }
149 
150 /* appends "#define str def\n" */
151 struct Buf *buf_strdefine (buf, str, def)
152      struct Buf *buf;
153      const char *str;
154      const char *def;
155 {
156 	buf_strappend (buf, "#define ");
157 	buf_strappend (buf, " ");
158 	buf_strappend (buf, str);
159 	buf_strappend (buf, " ");
160 	buf_strappend (buf, def);
161 	buf_strappend (buf, "\n");
162 	return buf;
163 }
164 
165 /** Pushes "m4_define( [[def]], [[val]])m4_dnl" to end of buffer.
166  * @param buf A buffer as a list of strings.
167  * @param def The m4 symbol to define.
168  * @param val The definition; may be NULL.
169  * @return buf
170  */
171 struct Buf *buf_m4_define (struct Buf *buf, const char* def, const char* val)
172 {
173     const char * fmt = "m4_define( [[%s]], [[%s]])m4_dnl\n";
174     char * str;
175     size_t strsz;
176 
177     val = val?val:"";
178     str = (char*)flex_alloc(strsz = strlen(fmt) + strlen(def) + strlen(val) + 2);
179     if (!str)
180         flexfatal (_("Allocation of buffer for m4 def failed"));
181 
182     snprintf(str, strsz, fmt, def, val);
183     buf_append(buf, &str, 1);
184     return buf;
185 }
186 
187 /** Pushes "m4_undefine([[def]])m4_dnl" to end of buffer.
188  * @param buf A buffer as a list of strings.
189  * @param def The m4 symbol to undefine.
190  * @return buf
191  */
192 struct Buf *buf_m4_undefine (struct Buf *buf, const char* def)
193 {
194     const char * fmt = "m4_undefine( [[%s]])m4_dnl\n";
195     char * str;
196     size_t strsz;
197 
198     str = (char*)flex_alloc(strsz = strlen(fmt) + strlen(def) + 2);
199     if (!str)
200         flexfatal (_("Allocation of buffer for m4 undef failed"));
201 
202     snprintf(str, strsz, fmt, def);
203     buf_append(buf, &str, 1);
204     return buf;
205 }
206 
207 /* create buf with 0 elements, each of size elem_size. */
208 void buf_init (buf, elem_size)
209      struct Buf *buf;
210      size_t elem_size;
211 {
212 	buf->elts = (void *) 0;
213 	buf->nelts = 0;
214 	buf->elt_size = elem_size;
215 	buf->nmax = 0;
216 }
217 
218 /* frees memory */
219 void buf_destroy (buf)
220      struct Buf *buf;
221 {
222 	if (buf && buf->elts)
223 		flex_free (buf->elts);
224 	buf->elts = (void *) 0;
225 }
226 
227 
228 /* appends ptr[] to buf, grow if necessary.
229  * n_elem is number of elements in ptr[], NOT bytes.
230  * returns buf.
231  * We grow by mod(512) boundaries.
232  */
233 
234 struct Buf *buf_append (buf, ptr, n_elem)
235      struct Buf *buf;
236      const void *ptr;
237      int n_elem;
238 {
239 	int     n_alloc = 0;
240 
241 	if (!ptr || n_elem == 0)
242 		return buf;
243 
244 	/* May need to alloc more. */
245 	if (n_elem + buf->nelts > buf->nmax) {
246 
247 		/* exact amount needed... */
248 		n_alloc = (n_elem + buf->nelts) * buf->elt_size;
249 
250 		/* ...plus some extra */
251 		if (((n_alloc * buf->elt_size) % 512) != 0
252 		    && buf->elt_size < 512)
253 			n_alloc +=
254 				(512 -
255 				 ((n_alloc * buf->elt_size) % 512)) /
256 				buf->elt_size;
257 
258 		if (!buf->elts)
259 			buf->elts =
260 				allocate_array (n_alloc, buf->elt_size);
261 		else
262 			buf->elts =
263 				reallocate_array (buf->elts, n_alloc,
264 						  buf->elt_size);
265 
266 		buf->nmax = n_alloc;
267 	}
268 
269 	memcpy ((char *) buf->elts + buf->nelts * buf->elt_size, ptr,
270 		n_elem * buf->elt_size);
271 	buf->nelts += n_elem;
272 
273 	return buf;
274 }
275 
276 /* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */
277