xref: /freebsd/contrib/flex/src/buf.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /* flex - tool to generate fast lexical analyzers */
2 
3 /*  Copyright (c) 1990 The Regents of the University of California. */
4 /*  All rights reserved. */
5 
6 /*  This code is derived from software contributed to Berkeley by */
7 /*  Vern Paxson. */
8 
9 /*  The United States Government has rights in this work pursuant */
10 /*  to contract no. DE-AC03-76SF00098 between the United States */
11 /*  Department of Energy and the University of California. */
12 
13 /*  This file is part of flex. */
14 
15 /*  Redistribution and use in source and binary forms, with or without */
16 /*  modification, are permitted provided that the following conditions */
17 /*  are met: */
18 
19 /*  1. Redistributions of source code must retain the above copyright */
20 /*     notice, this list of conditions and the following disclaimer. */
21 /*  2. Redistributions in binary form must reproduce the above copyright */
22 /*     notice, this list of conditions and the following disclaimer in the */
23 /*     documentation and/or other materials provided with the distribution. */
24 
25 /*  Neither the name of the University nor the names of its contributors */
26 /*  may be used to endorse or promote products derived from this software */
27 /*  without specific prior written permission. */
28 
29 /*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
30 /*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
31 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
32 /*  PURPOSE. */
33 
34 #include "flexdef.h"
35 
36 /* Take note: The buffer object is sometimes used as a String buffer (one
37  * continuous string), and sometimes used as a list of strings, usually line by
38  * line.
39  *
40  * The type is specified in buf_init by the elt_size. If the elt_size is
41  * sizeof(char), then the buffer should be treated as string buffer. If the
42  * elt_size is sizeof(char*), then the buffer should be treated as a list of
43  * strings.
44  *
45  * Certain functions are only appropriate for one type or the other.
46  */
47 
48 /* global buffers. */
49 struct Buf userdef_buf;		/**< for user #definitions triggered by cmd-line. */
50 struct Buf defs_buf;		/**< for #define's autogenerated. List of strings. */
51 struct Buf yydmap_buf;		/**< string buffer to hold yydmap elements */
52 struct Buf m4defs_buf;          /**< m4 definitions. List of strings. */
53 struct Buf top_buf;             /**< contains %top code. String buffer. */
54 
55 struct Buf *buf_print_strings(struct Buf * buf, FILE* out)
56 {
57     int i;
58 
59     if(!buf || !out)
60         return buf;
61 
62     for (i=0; i < buf->nelts; i++){
63         const char * s = ((char**)buf->elts)[i];
64         if(s)
65             fprintf(out, "%s", s);
66     }
67     return buf;
68 }
69 
70 /* Append a "%s" formatted string to a string buffer */
71 struct Buf *buf_prints (struct Buf *buf, const char *fmt, const char *s)
72 {
73 	char   *t;
74         size_t tsz;
75 
76 	tsz = strlen(fmt) + strlen(s) + 1;
77 	t = malloc(tsz);
78 	if (!t)
79 	    flexfatal (_("Allocation of buffer to print string failed"));
80 	snprintf (t, tsz, fmt, s);
81 	buf = buf_strappend (buf, t);
82 	free(t);
83 	return buf;
84 }
85 
86 /** Append a line directive to the string buffer.
87  * @param buf A string buffer.
88  * @param filename file name
89  * @param lineno line number
90  * @return buf
91  */
92 struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
93 {
94     char *dst, *t;
95     const char *src;
96     size_t tsz;
97 
98     if (gen_line_dirs)
99 	return buf;
100 
101     tsz = strlen("#line \"\"\n")                +   /* constant parts */
102                2 * strlen (filename)            +   /* filename with possibly all backslashes escaped */
103                NUMCHARLINES                     +   /* line number */
104                1;                                   /* NUL */
105     t = malloc(tsz);
106     if (!t)
107       flexfatal (_("Allocation of buffer for line directive failed"));
108     for (dst = t + snprintf (t, tsz, "#line %d \"", lineno), src = filename; *src; *dst++ = *src++)
109       if (*src == '\\')   /* escape backslashes */
110         *dst++ = '\\';
111     *dst++ = '"';
112     *dst++ = '\n';
113     *dst   = '\0';
114     buf = buf_strappend (buf, t);
115     free(t);
116     return buf;
117 }
118 
119 
120 /** Append the contents of @a src to @a dest.
121  * @param @a dest the destination buffer
122  * @param @a dest the source buffer
123  * @return @a dest
124  */
125 struct Buf *buf_concat(struct Buf* dest, const struct Buf* src)
126 {
127     buf_append(dest, src->elts, src->nelts);
128     return dest;
129 }
130 
131 
132 /* Appends n characters in str to buf. */
133 struct Buf *buf_strnappend (struct Buf *buf, const char *str, int n)
134 {
135 	buf_append (buf, str, n + 1);
136 
137 	/* "undo" the '\0' character that buf_append() already copied. */
138 	buf->nelts--;
139 
140 	return buf;
141 }
142 
143 /* Appends characters in str to buf. */
144 struct Buf *buf_strappend (struct Buf *buf, const char *str)
145 {
146 	return buf_strnappend (buf, str, (int) strlen (str));
147 }
148 
149 /* appends "#define str def\n" */
150 struct Buf *buf_strdefine (struct Buf *buf, const char *str, const char *def)
151 {
152 	buf_strappend (buf, "#define ");
153 	buf_strappend (buf, " ");
154 	buf_strappend (buf, str);
155 	buf_strappend (buf, " ");
156 	buf_strappend (buf, def);
157 	buf_strappend (buf, "\n");
158 	return buf;
159 }
160 
161 /** Pushes "m4_define( [[def]], [[val]])m4_dnl" to end of buffer.
162  * @param buf A buffer as a list of strings.
163  * @param def The m4 symbol to define.
164  * @param val The definition; may be NULL.
165  * @return buf
166  */
167 struct Buf *buf_m4_define (struct Buf *buf, const char* def, const char* val)
168 {
169     const char * fmt = "m4_define( [[%s]], [[[[%s]]]])m4_dnl\n";
170     char * str;
171     size_t strsz;
172 
173     val = val?val:"";
174     strsz = strlen(fmt) + strlen(def) + strlen(val) + 2;
175     str = malloc(strsz);
176     if (!str)
177         flexfatal (_("Allocation of buffer for m4 def failed"));
178 
179     snprintf(str, strsz, fmt, def, val);
180     buf_append(buf, &str, 1);
181     return buf;
182 }
183 
184 /** Pushes "m4_undefine([[def]])m4_dnl" to end of buffer.
185  * @param buf A buffer as a list of strings.
186  * @param def The m4 symbol to undefine.
187  * @return buf
188  */
189 struct Buf *buf_m4_undefine (struct Buf *buf, const char* def)
190 {
191     const char * fmt = "m4_undefine( [[%s]])m4_dnl\n";
192     char * str;
193     size_t strsz;
194 
195     strsz = strlen(fmt) + strlen(def) + 2;
196     str = malloc(strsz);
197     if (!str)
198         flexfatal (_("Allocation of buffer for m4 undef failed"));
199 
200     snprintf(str, strsz, fmt, def);
201     buf_append(buf, &str, 1);
202     return buf;
203 }
204 
205 /* create buf with 0 elements, each of size elem_size. */
206 void buf_init (struct Buf *buf, size_t elem_size)
207 {
208 	buf->elts = NULL;
209 	buf->nelts = 0;
210 	buf->elt_size = elem_size;
211 	buf->nmax = 0;
212 }
213 
214 /* frees memory */
215 void buf_destroy (struct Buf *buf)
216 {
217 	if (buf) {
218 		free(buf->elts);
219 		buf->elts = NULL;
220 	}
221 }
222 
223 
224 /* appends ptr[] to buf, grow if necessary.
225  * n_elem is number of elements in ptr[], NOT bytes.
226  * returns buf.
227  * We grow by mod(512) boundaries.
228  */
229 
230 struct Buf *buf_append (struct Buf *buf, const void *ptr, int n_elem)
231 {
232 	int     n_alloc = 0;
233 
234 	if (!ptr || n_elem == 0)
235 		return buf;
236 
237 	/* May need to alloc more. */
238 	if (n_elem + buf->nelts > buf->nmax) {
239 
240 		/* exact count needed... */
241 		n_alloc = n_elem + buf->nelts;
242 
243 		/* ...plus some extra */
244 		if ((((size_t) n_alloc * buf->elt_size) % 512) != 0
245 		    && buf->elt_size < 512)
246 			n_alloc += (int)
247 				((512 -
248 				 (((size_t) n_alloc * buf->elt_size) % 512)) /
249 				buf->elt_size);
250 
251 		if (!buf->elts)
252 			buf->elts =
253 				allocate_array ((int) n_alloc, buf->elt_size);
254 		else
255 			buf->elts =
256 				reallocate_array (buf->elts, (int) n_alloc,
257 						  buf->elt_size);
258 
259 		buf->nmax = n_alloc;
260 	}
261 
262 	memcpy ((char *) buf->elts + (size_t) buf->nelts * buf->elt_size, ptr,
263 		(size_t) n_elem * buf->elt_size);
264 	buf->nelts += n_elem;
265 
266 	return buf;
267 }
268 
269 /* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */
270