wimboot/wimboot-2.7.3/src/ipxe/vsprintf.c

   1 /*
   2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  */
  19
  20 FILE_LICENCE ( GPL2_OR_LATER );
  21
  22 #include <stddef.h>
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #include <wchar.h>
  27 #include <ipxe/vsprintf.h>
  28
  29 /** @file */
  30
  31 #define CHAR_LEN        0       /**< "hh" length modifier */
  32 #define SHORT_LEN       1       /**< "h" length modifier */
  33 #define INT_LEN         2       /**< no length modifier */
  34 #define LONG_LEN        3       /**< "l" length modifier */
  35 #define LONGLONG_LEN    4       /**< "ll" length modifier */
  36 #define SIZE_T_LEN      5       /**< "z" length modifier */
  37
  38 static uint8_t type_sizes[] = {
  39         [CHAR_LEN]      = sizeof ( char ),
  40         [SHORT_LEN]     = sizeof ( short ),
  41         [INT_LEN]       = sizeof ( int ),
  42         [LONG_LEN]      = sizeof ( long ),
  43         [LONGLONG_LEN]  = sizeof ( long long ),
  44         [SIZE_T_LEN]    = sizeof ( size_t ),
  45 };
  46
  47 /**
  48  * Use lower-case for hexadecimal digits
  49  *
  50  * Note that this value is set to 0x20 since that makes for very
  51  * efficient calculations.  (Bitwise-ORing with @c LCASE converts to a
  52  * lower-case character, for example.)
  53  */
  54 #define LCASE 0x20
  55
  56 /**
  57  * Use "alternate form"
  58  *
  59  * For hexadecimal numbers, this means to add a "0x" or "0X" prefix to
  60  * the number.
  61  */
  62 #define ALT_FORM 0x02
  63
  64 /**
  65  * Use zero padding
  66  *
  67  * Note that this value is set to 0x10 since that allows the pad
  68  * character to be calculated as @c 0x20|(flags&ZPAD)
  69  */
  70 #define ZPAD 0x10
  71
  72 /**
  73  * Format a hexadecimal number
  74  *
  75  * @v end               End of buffer to contain number
  76  * @v num               Number to format
  77  * @v width             Minimum field width
  78  * @v flags             Format flags
  79  * @ret ptr             End of buffer
  80  *
  81  * Fills a buffer in reverse order with a formatted hexadecimal
  82  * number.  The number will be zero-padded to the specified width.
  83  * Lower-case and "alternate form" (i.e. "0x" prefix) flags may be
  84  * set.
  85  *
  86  * There must be enough space in the buffer to contain the largest
  87  * number that this function can format.
  88  */
  89 static char * format_hex ( char *end, unsigned long long num, int width,
  90                            int flags ) {
  91         char *ptr = end;
  92         int case_mod = ( flags & LCASE );
  93         int pad = ( ( flags & ZPAD ) | ' ' );
  94
  95         /* Generate the number */
  96         do {
  97                 *(--ptr) = "0123456789ABCDEF"[ num & 0xf ] | case_mod;
  98                 num >>= 4;
  99         } while ( num );
 100
 101         /* Pad to width */
 102         while ( ( end - ptr ) < width )
 103                 *(--ptr) = pad;
 104
 105         /* Add "0x" or "0X" if alternate form specified */
 106         if ( flags & ALT_FORM ) {
 107                 *(--ptr) = 'X' | case_mod;
 108                 *(--ptr) = '0';
 109         }
 110
 111         return ptr;
 112 }
 113
 114 /**
 115  * Format a decimal number
 116  *
 117  * @v end               End of buffer to contain number
 118  * @v num               Number to format
 119  * @v width             Minimum field width
 120  * @v flags             Format flags
 121  * @ret ptr             End of buffer
 122  *
 123  * Fills a buffer in reverse order with a formatted decimal number.
 124  * The number will be space-padded to the specified width.
 125  *
 126  * There must be enough space in the buffer to contain the largest
 127  * number that this function can format.
 128  */
 129 static char * format_decimal ( char *end, signed long num, int width,
 130                                int flags ) {
 131         char *ptr = end;
 132         int negative = 0;
 133         int zpad = ( flags & ZPAD );
 134         int pad = ( zpad | ' ' );
 135
 136         /* Generate the number */
 137         if ( num < 0 ) {
 138                 negative = 1;
 139                 num = -num;
 140         }
 141         do {
 142                 *(--ptr) = '0' + ( num % 10 );
 143                 num /= 10;
 144         } while ( num );
 145
 146         /* Add "-" if necessary */
 147         if ( negative && ( ! zpad ) )
 148                 *(--ptr) = '-';
 149
 150         /* Pad to width */
 151         while ( ( end - ptr ) < width )
 152                 *(--ptr) = pad;
 153
 154         /* Add "-" if necessary */
 155         if ( negative && zpad )
 156                 *ptr = '-';
 157
 158         return ptr;
 159 }
 160
 161 /**
 162  * Print character via a printf context
 163  *
 164  * @v ctx               Context
 165  * @v c                 Character
 166  *
 167  * Call's the printf_context::handler() method and increments
 168  * printf_context::len.
 169  */
 170 static inline void cputchar ( struct printf_context *ctx, unsigned int c ) {
 171         ctx->handler ( ctx, c );
 172         ++ctx->len;
 173 }
 174
 175 /**
 176  * Write a formatted string to a printf context
 177  *
 178  * @v ctx               Context
 179  * @v fmt               Format string
 180  * @v args              Arguments corresponding to the format string
 181  * @ret len             Length of formatted string
 182  */
 183 size_t vcprintf ( struct printf_context *ctx, const char *fmt, va_list args ) {
 184         int flags;
 185         int width;
 186         uint8_t *length;
 187         char *ptr;
 188         char tmp_buf[32]; /* 32 is enough for all numerical formats.
 189                            * Insane width fields could overflow this buffer. */
 190         wchar_t *wptr;
 191
 192         /* Initialise context */
 193         ctx->len = 0;
 194
 195         for ( ; *fmt ; fmt++ ) {
 196                 /* Pass through ordinary characters */
 197                 if ( *fmt != '%' ) {
 198                         cputchar ( ctx, *fmt );
 199                         continue;
 200                 }
 201                 fmt++;
 202                 /* Process flag characters */
 203                 flags = 0;
 204                 for ( ; ; fmt++ ) {
 205                         if ( *fmt == '#' ) {
 206                                 flags |= ALT_FORM;
 207                         } else if ( *fmt == '0' ) {
 208                                 flags |= ZPAD;
 209                         } else {
 210                                 /* End of flag characters */
 211                                 break;
 212                         }
 213                 }
 214                 /* Process field width */
 215                 width = 0;
 216                 for ( ; ; fmt++ ) {
 217                         if ( ( ( unsigned ) ( *fmt - '0' ) ) < 10 ) {
 218                                 width = ( width * 10 ) + ( *fmt - '0' );
 219                         } else {
 220                                 break;
 221                         }
 222                 }
 223                 /* We don't do floating point */
 224                 /* Process length modifier */
 225                 length = &type_sizes[INT_LEN];
 226                 for ( ; ; fmt++ ) {
 227                         if ( *fmt == 'h' ) {
 228                                 length--;
 229                         } else if ( *fmt == 'l' ) {
 230                                 length++;
 231                         } else if ( *fmt == 'z' ) {
 232                                 length = &type_sizes[SIZE_T_LEN];
 233                         } else {
 234                                 break;
 235                         }
 236                 }
 237                 /* Process conversion specifier */
 238                 ptr = tmp_buf + sizeof ( tmp_buf ) - 1;
 239                 *ptr = '\0';
 240                 wptr = NULL;
 241                 if ( *fmt == 'c' ) {
 242                         if ( length < &type_sizes[LONG_LEN] ) {
 243                                 cputchar ( ctx, va_arg ( args, unsigned int ) );
 244                         } else {
 245                                 wchar_t wc;
 246                                 size_t len;
 247
 248                                 wc = va_arg ( args, wint_t );
 249                                 len = wcrtomb ( tmp_buf, wc, NULL );
 250                                 tmp_buf[len] = '\0';
 251                                 ptr = tmp_buf;
 252                         }
 253                 } else if ( *fmt == 's' ) {
 254                         if ( length < &type_sizes[LONG_LEN] ) {
 255                                 ptr = va_arg ( args, char * );
 256                         } else {
 257                                 wptr = va_arg ( args, wchar_t * );
 258                         }
 259                         if ( ( ptr == NULL ) && ( wptr == NULL ) )
 260                                 ptr = "<NULL>";
 261                 } else if ( *fmt == 'p' ) {
 262                         intptr_t ptrval;
 263
 264                         ptrval = ( intptr_t ) va_arg ( args, void * );
 265                         ptr = format_hex ( ptr, ptrval, width,
 266                                            ( ALT_FORM | LCASE ) );
 267                 } else if ( ( *fmt & ~0x20 ) == 'X' ) {
 268                         unsigned long long hex;
 269
 270                         flags |= ( *fmt & 0x20 ); /* LCASE */
 271                         if ( *length >= sizeof ( unsigned long long ) ) {
 272                                 hex = va_arg ( args, unsigned long long );
 273                         } else if ( *length >= sizeof ( unsigned long ) ) {
 274                                 hex = va_arg ( args, unsigned long );
 275                         } else {
 276                                 hex = va_arg ( args, unsigned int );
 277                         }
 278                         ptr = format_hex ( ptr, hex, width, flags );
 279                 } else if ( ( *fmt == 'd' ) || ( *fmt == 'i' ) ){
 280                         signed long decimal;
 281
 282                         if ( *length >= sizeof ( signed long ) ) {
 283                                 decimal = va_arg ( args, signed long );
 284                         } else {
 285                                 decimal = va_arg ( args, signed int );
 286                         }
 287                         ptr = format_decimal ( ptr, decimal, width, flags );
 288                 } else {
 289                         *(--ptr) = *fmt;
 290                 }
 291                 /* Write out conversion result */
 292                 if ( wptr == NULL ) {
 293                         for ( ; *ptr ; ptr++ ) {
 294                                 cputchar ( ctx, *ptr );
 295                         }
 296                 } else {
 297                         for ( ; *wptr ; wptr++ ) {
 298                                 size_t len = wcrtomb ( tmp_buf, *wptr, NULL );
 299                                 for ( ptr = tmp_buf ; len-- ; ptr++ ) {
 300                                         cputchar ( ctx, *ptr );
 301                                 }
 302                         }
 303                 }
 304         }
 305
 306         return ctx->len;
 307 }
 308
 309 /** Context used by vsnprintf() and friends */
 310 struct sputc_context {
 311         struct printf_context ctx;
 312         /** Buffer for formatted string (used by printf_sputc()) */
 313         char *buf;
 314         /** Buffer length (used by printf_sputc()) */
 315         size_t max_len;
 316 };
 317
 318 /**
 319  * Write character to buffer
 320  *
 321  * @v ctx               Context
 322  * @v c                 Character
 323  */
 324 static void printf_sputc ( struct printf_context *ctx, unsigned int c ) {
 325         struct sputc_context * sctx =
 326                 container_of ( ctx, struct sputc_context, ctx );
 327
 328         if ( ctx->len < sctx->max_len )
 329                 sctx->buf[ctx->len] = c;
 330 }
 331
 332 /**
 333  * Write a formatted string to a buffer
 334  *
 335  * @v buf               Buffer into which to write the string
 336  * @v size              Size of buffer
 337  * @v fmt               Format string
 338  * @v args              Arguments corresponding to the format string
 339  * @ret len             Length of formatted string
 340  *
 341  * If the buffer is too small to contain the string, the returned
 342  * length is the length that would have been written had enough space
 343  * been available.
 344  */
 345 int vsnprintf ( char *buf, size_t size, const char *fmt, va_list args ) {
 346         struct sputc_context sctx;
 347         size_t len;
 348         size_t end;
 349
 350         /* Hand off to vcprintf */
 351         sctx.ctx.handler = printf_sputc;
 352         sctx.buf = buf;
 353         sctx.max_len = size;
 354         len = vcprintf ( &sctx.ctx, fmt, args );
 355
 356         /* Add trailing NUL */
 357         if ( size ) {
 358                 end = size - 1;
 359                 if ( len < end )
 360                         end = len;
 361                 buf[end] = '\0';
 362         }
 363
 364         return len;
 365 }
 366
 367 /**
 368  * Write a formatted string to a buffer
 369  *
 370  * @v buf               Buffer into which to write the string
 371  * @v size              Size of buffer
 372  * @v fmt               Format string
 373  * @v ...               Arguments corresponding to the format string
 374  * @ret len             Length of formatted string
 375  */
 376 int snprintf ( char *buf, size_t size, const char *fmt, ... ) {
 377         va_list args;
 378         int i;
 379
 380         va_start ( args, fmt );
 381         i = vsnprintf ( buf, size, fmt, args );
 382         va_end ( args );
 383         return i;
 384 }
 385
 386 /**
 387  * Version of vsnprintf() that accepts a signed buffer size
 388  *
 389  * @v buf               Buffer into which to write the string
 390  * @v size              Size of buffer
 391  * @v fmt               Format string
 392  * @v args              Arguments corresponding to the format string
 393  * @ret len             Length of formatted string
 394  */
 395 int vssnprintf ( char *buf, ssize_t ssize, const char *fmt, va_list args ) {
 396
 397         /* Treat negative buffer size as zero buffer size */
 398         if ( ssize < 0 )
 399                 ssize = 0;
 400
 401         /* Hand off to vsnprintf */
 402         return vsnprintf ( buf, ssize, fmt, args );
 403 }
 404
 405 /**
 406  * Version of vsnprintf() that accepts a signed buffer size
 407  *
 408  * @v buf               Buffer into which to write the string
 409  * @v size              Size of buffer
 410  * @v fmt               Format string
 411  * @v ...               Arguments corresponding to the format string
 412  * @ret len             Length of formatted string
 413  */
 414 int ssnprintf ( char *buf, ssize_t ssize, const char *fmt, ... ) {
 415         va_list args;
 416         int len;
 417
 418         /* Hand off to vssnprintf */
 419         va_start ( args, fmt );
 420         len = vssnprintf ( buf, ssize, fmt, args );
 421         va_end ( args );
 422         return len;
 423 }
 424
 425 /**
 426  * Write character to console
 427  *
 428  * @v ctx               Context
 429  * @v c                 Character
 430  */
 431 static void printf_putchar ( struct printf_context *ctx __unused,
 432                              unsigned int c ) {
 433         putchar ( c );
 434 }
 435
 436 /**
 437  * Write a formatted string to the console
 438  *
 439  * @v fmt               Format string
 440  * @v args              Arguments corresponding to the format string
 441  * @ret len             Length of formatted string
 442  */
 443 int vprintf ( const char *fmt, va_list args ) {
 444         struct printf_context ctx;
 445
 446         /* Hand off to vcprintf */
 447         ctx.handler = printf_putchar;
 448         return vcprintf ( &ctx, fmt, args );
 449 }
 450
 451 /**
 452  * Write a formatted string to the console.
 453  *
 454  * @v fmt               Format string
 455  * @v ...               Arguments corresponding to the format string
 456  * @ret len             Length of formatted string
 457  */
 458 int printf ( const char *fmt, ... ) {
 459         va_list args;
 460         int i;
 461
 462         va_start ( args, fmt );
 463         i = vprintf ( fmt, args );
 464         va_end ( args );
 465         return i;
 466 }