xref: /netbsd/external/bsd/flex/dist/src/buf.c (revision b806bde9)
1 /*	$NetBSD: buf.c,v 1.3 2017/01/02 17:45:27 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 #include "flexdef.h"
36 __RCSID("$NetBSD: buf.c,v 1.3 2017/01/02 17:45:27 christos Exp $");
37 
38 
39 /* Take note: The buffer object is sometimes used as a String buffer (one
40  * continuous string), and sometimes used as a list of strings, usually line by
41  * line.
42  *
43  * The type is specified in buf_init by the elt_size. If the elt_size is
44  * sizeof(char), then the buffer should be treated as string buffer. If the
45  * elt_size is sizeof(char*), then the buffer should be treated as a list of
46  * strings.
47  *
48  * Certain functions are only appropriate for one type or the other.
49  */
50 
51 /* global buffers. */
52 struct Buf userdef_buf;		/**< for user #definitions triggered by cmd-line. */
53 struct Buf defs_buf;		/**< for #define's autogenerated. List of strings. */
54 struct Buf yydmap_buf;		/**< string buffer to hold yydmap elements */
55 struct Buf m4defs_buf;          /**< m4 definitions. List of strings. */
56 struct Buf top_buf;             /**< contains %top code. String buffer. */
57 
buf_print_strings(struct Buf * buf,FILE * out)58 struct Buf *buf_print_strings(struct Buf * buf, FILE* out)
59 {
60     int i;
61 
62     if(!buf || !out)
63         return buf;
64 
65     for (i=0; i < buf->nelts; i++){
66         const char * s = ((char**)buf->elts)[i];
67         if(s)
68             fprintf(out, "%s", s);
69     }
70     return buf;
71 }
72 
73 /* Append a "%s" formatted string to a string buffer */
buf_prints(struct Buf * buf,const char * fmt,const char * s)74 struct Buf *buf_prints (struct Buf *buf, const char *fmt, const char *s)
75 {
76 	char   *t;
77         size_t tsz;
78 
79 	tsz = strlen(fmt) + strlen(s) + 1;
80 	t = malloc(tsz);
81 	if (!t)
82 	    flexfatal (_("Allocation of buffer to print string failed"));
83 	snprintf (t, tsz, fmt, s);
84 	buf = buf_strappend (buf, t);
85 	free(t);
86 	return buf;
87 }
88 
89 /** Append a line directive to the string buffer.
90  * @param buf A string buffer.
91  * @param filename file name
92  * @param lineno line number
93  * @return buf
94  */
buf_linedir(struct Buf * buf,const char * filename,int lineno)95 struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
96 {
97     char *dst, *t;
98     const char *src;
99     size_t tsz;
100 
101     if (gen_line_dirs)
102 	return buf;
103 
104     tsz = strlen("#line \"\"\n")                +   /* constant parts */
105                2 * strlen (filename)            +   /* filename with possibly all backslashes escaped */
106                (size_t) (1 + ceil (log10 (abs (lineno)))) +   /* line number */
107                1;                                   /* NUL */
108     t = malloc(tsz);
109     if (!t)
110       flexfatal (_("Allocation of buffer for line directive failed"));
111     for (dst = t + snprintf (t, tsz, "#line %d \"", lineno), src = filename; *src; *dst++ = *src++)
112       if (*src == '\\')   /* escape backslashes */
113         *dst++ = '\\';
114     *dst++ = '"';
115     *dst++ = '\n';
116     *dst   = '\0';
117     buf = buf_strappend (buf, t);
118     free(t);
119     return buf;
120 }
121 
122 
123 /** Append the contents of @a src to @a dest.
124  * @param @a dest the destination buffer
125  * @param @a dest the source buffer
126  * @return @a dest
127  */
buf_concat(struct Buf * dest,const struct Buf * src)128 struct Buf *buf_concat(struct Buf* dest, const struct Buf* src)
129 {
130     buf_append(dest, src->elts, src->nelts);
131     return dest;
132 }
133 
134 
135 /* Appends n characters in str to buf. */
buf_strnappend(struct Buf * buf,const char * str,int n)136 struct Buf *buf_strnappend (struct Buf *buf, const char *str, int n)
137 {
138 	buf_append (buf, str, n + 1);
139 
140 	/* "undo" the '\0' character that buf_append() already copied. */
141 	buf->nelts--;
142 
143 	return buf;
144 }
145 
146 /* Appends characters in str to buf. */
buf_strappend(struct Buf * buf,const char * str)147 struct Buf *buf_strappend (struct Buf *buf, const char *str)
148 {
149 	return buf_strnappend (buf, str, (int) strlen (str));
150 }
151 
152 /* appends "#define str def\n" */
buf_strdefine(struct Buf * buf,const char * str,const char * def)153 struct Buf *buf_strdefine (struct Buf *buf, const char *str, const char *def)
154 {
155 	buf_strappend (buf, "#define ");
156 	buf_strappend (buf, " ");
157 	buf_strappend (buf, str);
158 	buf_strappend (buf, " ");
159 	buf_strappend (buf, def);
160 	buf_strappend (buf, "\n");
161 	return buf;
162 }
163 
164 /** Pushes "m4_define( [[def]], [[val]])m4_dnl" to end of buffer.
165  * @param buf A buffer as a list of strings.
166  * @param def The m4 symbol to define.
167  * @param val The definition; may be NULL.
168  * @return buf
169  */
buf_m4_define(struct Buf * buf,const char * def,const char * val)170 struct Buf *buf_m4_define (struct Buf *buf, const char* def, const char* val)
171 {
172     const char * fmt = "m4_define( [[%s]], [[[[%s]]]])m4_dnl\n";
173     char * str;
174     size_t strsz;
175 
176     val = val?val:"";
177     strsz = strlen(fmt) + strlen(def) + strlen(val) + 2;
178     str = malloc(strsz);
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  */
buf_m4_undefine(struct Buf * buf,const char * def)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     strsz = strlen(fmt) + strlen(def) + 2;
199     str = malloc(strsz);
200     if (!str)
201         flexfatal (_("Allocation of buffer for m4 undef failed"));
202 
203     snprintf(str, strsz, fmt, def);
204     buf_append(buf, &str, 1);
205     return buf;
206 }
207 
208 /* create buf with 0 elements, each of size elem_size. */
buf_init(struct Buf * buf,size_t elem_size)209 void buf_init (struct Buf *buf, size_t elem_size)
210 {
211 	buf->elts = NULL;
212 	buf->nelts = 0;
213 	buf->elt_size = elem_size;
214 	buf->nmax = 0;
215 }
216 
217 /* frees memory */
buf_destroy(struct Buf * buf)218 void buf_destroy (struct Buf *buf)
219 {
220 	if (buf) {
221 		free(buf->elts);
222 		buf->elts = NULL;
223 	}
224 }
225 
226 
227 /* appends ptr[] to buf, grow if necessary.
228  * n_elem is number of elements in ptr[], NOT bytes.
229  * returns buf.
230  * We grow by mod(512) boundaries.
231  */
232 
buf_append(struct Buf * buf,const void * ptr,int n_elem)233 struct Buf *buf_append (struct Buf *buf, const void *ptr, int n_elem)
234 {
235 	int     n_alloc = 0;
236 
237 	if (!ptr || n_elem == 0)
238 		return buf;
239 
240 	/* May need to alloc more. */
241 	if (n_elem + buf->nelts > buf->nmax) {
242 
243 		/* exact count needed... */
244 		n_alloc = n_elem + buf->nelts;
245 
246 		/* ...plus some extra */
247 		if ((((size_t) n_alloc * buf->elt_size) % 512) != 0
248 		    && buf->elt_size < 512)
249 			n_alloc += (int)
250 				((512 -
251 				 (((size_t) n_alloc * buf->elt_size) % 512)) /
252 				buf->elt_size);
253 
254 		if (!buf->elts)
255 			buf->elts =
256 				allocate_array ((int) n_alloc, buf->elt_size);
257 		else
258 			buf->elts =
259 				reallocate_array (buf->elts, (int) n_alloc,
260 						  buf->elt_size);
261 
262 		buf->nmax = n_alloc;
263 	}
264 
265 	memcpy ((char *) buf->elts + (size_t) buf->nelts * buf->elt_size, ptr,
266 		(size_t) n_elem * buf->elt_size);
267 	buf->nelts += n_elem;
268 
269 	return buf;
270 }
271 
272 /* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */
273