src/format.c

   1 /* GNU m4 -- A simple macro processor
   2
   3    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2006
   4    Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19    02110-1301  USA
  20 */
  21
  22 /* printf like formatting for m4.  */
  23
  24 #include "m4.h"
  25 #include "xvasprintf.h"
  26
  27 /* Simple varargs substitute.  */
  28
  29 #define ARG_INT(argc, argv) \
  30         ((argc == 0) ? 0 : \
  31          (--argc, argv++, atoi (TOKEN_DATA_TEXT (argv[-1]))))
  32
  33 #define ARG_UINT(argc, argv) \
  34         ((argc == 0) ? 0 : \
  35          (--argc, argv++, (unsigned int) atoi (TOKEN_DATA_TEXT (argv[-1]))))
  36
  37 #define ARG_LONG(argc, argv) \
  38         ((argc == 0) ? 0 : \
  39          (--argc, argv++, atol (TOKEN_DATA_TEXT (argv[-1]))))
  40
  41 #define ARG_ULONG(argc, argv) \
  42         ((argc == 0) ? 0 : \
  43          (--argc, argv++, (unsigned long) atol (TOKEN_DATA_TEXT (argv[-1]))))
  44
  45 #define ARG_STR(argc, argv) \
  46         ((argc == 0) ? "" : \
  47          (--argc, argv++, TOKEN_DATA_TEXT (argv[-1])))
  48
  49 #define ARG_DOUBLE(argc, argv) \
  50         ((argc == 0) ? 0 : \
  51          (--argc, argv++, atof (TOKEN_DATA_TEXT (argv[-1]))))
  52 \f
  53
  54 /*------------------------------------------------------------------------.
  55 | The main formatting function.  Output is placed on the obstack OBS, the |
  56 | first argument in ARGV is the formatting string, and the rest is        |
  57 | arguments for the string.                                               |
  58 `------------------------------------------------------------------------*/
  59
  60 void
  61 format (struct obstack *obs, int argc, token_data **argv)
  62 {
  63   char *fmt;                    /* format control string */
  64   const char *fstart;           /* beginning of current format spec */
  65   int c;                        /* a simple character */
  66
  67   /* Flags.  */
  68   char flags;                   /* 1 iff treating flags */
  69
  70   /* Precision specifiers.  */
  71   int width;                    /* minimum field width */
  72   int prec;                     /* precision */
  73   char lflag;                   /* long flag */
  74   char hflag;                   /* short flag */
  75
  76   /* Buffer and stuff.  */
  77   char *str;                    /* malloc'd buffer of formatted text */
  78   enum {INT, UINT, LONG, ULONG, DOUBLE, STR} datatype;
  79
  80   fmt = ARG_STR (argc, argv);
  81   for (;;)
  82     {
  83       while ((c = *fmt++) != '%')
  84         {
  85           if (c == 0)
  86             return;
  87           obstack_1grow (obs, c);
  88         }
  89
  90       fstart = fmt - 1;
  91
  92       if (*fmt == '%')
  93         {
  94           obstack_1grow (obs, '%');
  95           fmt++;
  96           continue;
  97         }
  98
  99       /* Parse flags.  */
 100       flags = 1;
 101       do
 102         {
 103           switch (*fmt)
 104             {
 105             case '-':           /* left justification */
 106             case '+':           /* mandatory sign */
 107             case ' ':           /* space instead of positive sign */
 108             case '0':           /* zero padding */
 109             case '#':           /* alternate output */
 110               break;
 111
 112             default:
 113               flags = 0;
 114               break;
 115             }
 116         }
 117       while (flags && fmt++);
 118
 119       /* Minimum field width.  */
 120       width = -1;
 121       if (*fmt == '*')
 122         {
 123           width = ARG_INT (argc, argv);
 124           fmt++;
 125         }
 126       else if (isdigit (to_uchar (*fmt)))
 127         {
 128           do
 129             {
 130               fmt++;
 131             }
 132           while (isdigit (to_uchar (*fmt)));
 133         }
 134
 135       /* Maximum precision.  */
 136       prec = -1;
 137       if (*fmt == '.')
 138         {
 139           if (*(++fmt) == '*')
 140             {
 141               prec = ARG_INT (argc, argv);
 142               ++fmt;
 143             }
 144           else if (isdigit (to_uchar (*fmt)))
 145             {
 146               do
 147                 {
 148                   fmt++;
 149                 }
 150               while (isdigit (to_uchar (*fmt)));
 151             }
 152         }
 153
 154       /* Length modifiers.  */
 155       lflag = (*fmt == 'l');
 156       hflag = (*fmt == 'h');
 157       if (lflag || hflag)
 158         fmt++;
 159
 160       switch (*fmt++)
 161         {
 162
 163         case '\0':
 164           return;
 165
 166         case 'c':
 167           datatype = INT;
 168           break;
 169
 170         case 's':
 171           datatype = STR;
 172           break;
 173
 174         case 'd':
 175         case 'i':
 176           if (lflag)
 177             {
 178               datatype = LONG;
 179             }
 180           else
 181             {
 182               datatype = INT;
 183             }
 184           break;
 185
 186         case 'o':
 187         case 'x':
 188         case 'X':
 189         case 'u':
 190           if (lflag)
 191             {
 192               datatype = ULONG;
 193             }
 194           else
 195             {
 196               datatype = UINT;
 197             }
 198           break;
 199
 200         case 'e':
 201         case 'E':
 202         case 'f':
 203         case 'F':
 204         case 'g':
 205         case 'G':
 206           datatype = DOUBLE;
 207           break;
 208
 209         default:
 210           continue;
 211         }
 212
 213       c = *fmt;
 214       *fmt = '\0';
 215
 216       switch(datatype)
 217         {
 218         case INT:
 219           if (width != -1 && prec != -1)
 220             str = xasprintf (fstart, width, prec, ARG_INT(argc, argv));
 221           else if (width != -1)
 222             str = xasprintf (fstart, width, ARG_INT(argc, argv));
 223           else if (prec != -1)
 224             str = xasprintf (fstart, prec, ARG_INT(argc, argv));
 225           else
 226             str = xasprintf (fstart, ARG_INT(argc, argv));
 227           break;
 228
 229         case UINT:
 230           if (width != -1 && prec != -1)
 231             str = xasprintf (fstart, width, prec, ARG_UINT(argc, argv));
 232           else if (width != -1)
 233             str = xasprintf (fstart, width, ARG_UINT(argc, argv));
 234           else if (prec != -1)
 235             str = xasprintf (fstart, prec, ARG_UINT(argc, argv));
 236           else
 237             str = xasprintf (fstart, ARG_UINT(argc, argv));
 238           break;
 239
 240         case LONG:
 241           if (width != -1 && prec != -1)
 242             str = xasprintf (fstart, width, prec, ARG_LONG(argc, argv));
 243           else if (width != -1)
 244             str = xasprintf (fstart, width, ARG_LONG(argc, argv));
 245           else if (prec != -1)
 246             str = xasprintf (fstart, prec, ARG_LONG(argc, argv));
 247           else
 248             str = xasprintf (fstart, ARG_LONG(argc, argv));
 249           break;
 250
 251         case ULONG:
 252           if (width != -1 && prec != -1)
 253             str = xasprintf (fstart, width, prec, ARG_ULONG(argc, argv));
 254           else if (width != -1)
 255             str = xasprintf (fstart, width, ARG_ULONG(argc, argv));
 256           else if (prec != -1)
 257             str = xasprintf (fstart, prec, ARG_ULONG(argc, argv));
 258           else
 259             str = xasprintf (fstart, ARG_ULONG(argc, argv));
 260           break;
 261
 262         case DOUBLE:
 263           if (width != -1 && prec != -1)
 264             str = xasprintf (fstart, width, prec, ARG_DOUBLE(argc, argv));
 265           else if (width != -1)
 266             str = xasprintf (fstart, width, ARG_DOUBLE(argc, argv));
 267           else if (prec != -1)
 268             str = xasprintf (fstart, prec, ARG_DOUBLE(argc, argv));
 269           else
 270             str = xasprintf (fstart, ARG_DOUBLE(argc, argv));
 271           break;
 272
 273         case STR:
 274           if (width != -1 && prec != -1)
 275             str = xasprintf (fstart, width, prec, ARG_STR(argc, argv));
 276           else if (width != -1)
 277             str = xasprintf (fstart, width, ARG_STR(argc, argv));
 278           else if (prec != -1)
 279             str = xasprintf (fstart, prec, ARG_STR(argc, argv));
 280           else
 281             str = xasprintf (fstart, ARG_STR(argc, argv));
 282           break;
 283
 284         default:
 285           abort();
 286         }
 287
 288       *fmt = c;
 289
 290       /* NULL was returned on failure, such as invalid format string.  For
 291          now, just silently ignore that bad specifier.  */
 292       if (str == NULL)
 293         continue;
 294
 295       obstack_grow (obs, str, strlen (str));
 296       free (str);
 297     }
 298 }