buf.c revision 228072 
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. */
49struct Buf userdef_buf;		/**< for user #definitions triggered by cmd-line. */
50struct Buf defs_buf;		/**< for #define's autogenerated. List of strings. */
51struct Buf yydmap_buf;		/**< string buffer to hold yydmap elements */
52struct Buf m4defs_buf;          /**< m4 definitions. List of strings. */
53struct Buf top_buf;             /**< contains %top code. String buffer. */
54
55struct 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 */
71struct Buf *buf_prints (struct Buf *buf, const char *fmt, const char *s)
72{
73	char   *t;
74        size_t tsz;
75
76	t = flex_alloc (tsz = strlen (fmt) + strlen (s) + 1);
77	snprintf (t, tsz, fmt, s);
78	buf = buf_strappend (buf, t);
79	flex_free (t);
80	return buf;
81}
82
83/** Append a line directive to the string buffer.
84 * @param buf A string buffer.
85 * @param filename file name
86 * @param lineno line number
87 * @return buf
88 */
89struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
90{
91    char   *t, *fmt = "#line %d \"%s\"\n";
92    size_t tsz;
93
94    t = flex_alloc (tsz = strlen (fmt) + strlen (filename) + (int)(1 + log10(lineno>=0?lineno:-lineno)) + 1);
95    snprintf (t, tsz, fmt, lineno, filename);
96    buf = buf_strappend (buf, t);
97    flex_free (t);
98    return buf;
99}
100
101
102/** Append the contents of @a src to @a dest.
103 * @param @a dest the destination buffer
104 * @param @a dest the source buffer
105 * @return @a dest
106 */
107struct Buf *buf_concat(struct Buf* dest, const struct Buf* src)
108{
109    buf_append(dest, src->elts, src->nelts);
110    return dest;
111}
112
113
114/* Appends n characters in str to buf. */
115struct Buf *buf_strnappend (buf, str, n)
116     struct Buf *buf;
117     const char *str;
118     int n;
119{
120	buf_append (buf, str, n + 1);
121
122	/* "undo" the '\0' character that buf_append() already copied. */
123	buf->nelts--;
124
125	return buf;
126}
127
128/* Appends characters in str to buf. */
129struct Buf *buf_strappend (buf, str)
130     struct Buf *buf;
131     const char *str;
132{
133	return buf_strnappend (buf, str, strlen (str));
134}
135
136/* appends "#define str def\n" */
137struct Buf *buf_strdefine (buf, str, def)
138     struct Buf *buf;
139     const char *str;
140     const char *def;
141{
142	buf_strappend (buf, "#define ");
143	buf_strappend (buf, " ");
144	buf_strappend (buf, str);
145	buf_strappend (buf, " ");
146	buf_strappend (buf, def);
147	buf_strappend (buf, "\n");
148	return buf;
149}
150
151/** Pushes "m4_define( [[def]], [[val]])m4_dnl" to end of buffer.
152 * @param buf A buffer as a list of strings.
153 * @param def The m4 symbol to define.
154 * @param val The definition; may be NULL.
155 * @return buf
156 */
157struct Buf *buf_m4_define (struct Buf *buf, const char* def, const char* val)
158{
159    const char * fmt = "m4_define( [[%s]], [[%s]])m4_dnl\n";
160    char * str;
161    size_t strsz;
162
163    val = val?val:"";
164    str = (char*)flex_alloc(strsz = strlen(fmt) + strlen(def) + strlen(val) + 2);
165
166    snprintf(str, strsz, fmt, def, val);
167    buf_append(buf, &str, 1);
168    return buf;
169}
170
171/** Pushes "m4_undefine([[def]])m4_dnl" to end of buffer.
172 * @param buf A buffer as a list of strings.
173 * @param def The m4 symbol to undefine.
174 * @return buf
175 */
176struct Buf *buf_m4_undefine (struct Buf *buf, const char* def)
177{
178    const char * fmt = "m4_undefine( [[%s]])m4_dnl\n";
179    char * str;
180    size_t strsz;
181
182    str = (char*)flex_alloc(strsz = strlen(fmt) + strlen(def) + 2);
183
184    snprintf(str, strsz, fmt, def);
185    buf_append(buf, &str, 1);
186    return buf;
187}
188
189/* create buf with 0 elements, each of size elem_size. */
190void buf_init (buf, elem_size)
191     struct Buf *buf;
192     size_t elem_size;
193{
194	buf->elts = (void *) 0;
195	buf->nelts = 0;
196	buf->elt_size = elem_size;
197	buf->nmax = 0;
198}
199
200/* frees memory */
201void buf_destroy (buf)
202     struct Buf *buf;
203{
204	if (buf && buf->elts)
205		flex_free (buf->elts);
206	buf->elts = (void *) 0;
207}
208
209
210/* appends ptr[] to buf, grow if necessary.
211 * n_elem is number of elements in ptr[], NOT bytes.
212 * returns buf.
213 * We grow by mod(512) boundaries.
214 */
215
216struct Buf *buf_append (buf, ptr, n_elem)
217     struct Buf *buf;
218     const void *ptr;
219     int n_elem;
220{
221	int     n_alloc = 0;
222
223	if (!ptr || n_elem == 0)
224		return buf;
225
226	/* May need to alloc more. */
227	if (n_elem + buf->nelts > buf->nmax) {
228
229		/* exact amount needed... */
230		n_alloc = (n_elem + buf->nelts) * buf->elt_size;
231
232		/* ...plus some extra */
233		if (((n_alloc * buf->elt_size) % 512) != 0
234		    && buf->elt_size < 512)
235			n_alloc +=
236				(512 -
237				 ((n_alloc * buf->elt_size) % 512)) /
238				buf->elt_size;
239
240		if (!buf->elts)
241			buf->elts =
242				allocate_array (n_alloc, buf->elt_size);
243		else
244			buf->elts =
245				reallocate_array (buf->elts, n_alloc,
246						  buf->elt_size);
247
248		buf->nmax = n_alloc;
249	}
250
251	memcpy ((char *) buf->elts + buf->nelts * buf->elt_size, ptr,
252		n_elem * buf->elt_size);
253	buf->nelts += n_elem;
254
255	return buf;
256}
257
258/* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */
259