contrib/flex/buf.c

   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 \f
  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         t = flex_alloc (tsz = strlen (fmt) + strlen (s) + 1);
  77         if (!t)
  78             flexfatal (_("Allocation of buffer to print string failed"));
  79         snprintf (t, tsz, fmt, s);
  80         buf = buf_strappend (buf, t);
  81         flex_free (t);
  82         return buf;
  83 }
  84
  85 /** Append a line directive to the string buffer.
  86  * @param buf A string buffer.
  87  * @param filename file name
  88  * @param lineno line number
  89  * @return buf
  90  */
  91 struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
  92 {
  93     char *dst, *src, *t;
  94     char *dupe;
  95
  96     dupe = flex_alloc (strlen(filename) + 1);
  97     strncpy(dupe, filename, strlen(filename));
  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 = dupe; *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: */