nsz Git - cparser/blob - format_check.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <ctype.h>
  21 #include <wctype.h>
  22
  23 #include "format_check.h"
  24 #include "symbol_t.h"
  25 #include "ast_t.h"
  26 #include "diagnostic.h"
  27 #include "types.h"
  28 #include "type_t.h"
  29 #include "warning.h"
  30 #include "lang_features.h"
  31
  32 typedef enum format_flag_t {
  33         FMT_FLAG_NONE  = 0,
  34         FMT_FLAG_HASH  = 1U << 0,
  35         FMT_FLAG_ZERO  = 1U << 1,
  36         FMT_FLAG_MINUS = 1U << 2,
  37         FMT_FLAG_SPACE = 1U << 3,
  38         FMT_FLAG_PLUS  = 1U << 4,
  39         FMT_FLAG_TICK  = 1U << 5
  40 } format_flag_t;
  41
  42 typedef unsigned format_flags_t;
  43
  44 typedef enum format_length_modifier_t {
  45         FMT_MOD_NONE,
  46         FMT_MOD_L,
  47         FMT_MOD_hh,
  48         FMT_MOD_h,
  49         FMT_MOD_l,
  50         FMT_MOD_ll,
  51         FMT_MOD_j,
  52         FMT_MOD_t,
  53         FMT_MOD_z,
  54         FMT_MOD_q,
  55         /* only in microsoft mode */
  56         FMT_MOD_w,
  57         FMT_MOD_I,
  58         FMT_MOD_I32,
  59         FMT_MOD_I64
  60 } format_length_modifier_t;
  61
  62 static const char* get_length_modifier_name(const format_length_modifier_t mod)
  63 {
  64         static const char* const names[] = {
  65                 [FMT_MOD_NONE] = "",
  66                 [FMT_MOD_L]    = "L",
  67                 [FMT_MOD_hh]   = "hh",
  68                 [FMT_MOD_h]    = "h",
  69                 [FMT_MOD_l]    = "l",
  70                 [FMT_MOD_ll]   = "ll",
  71                 [FMT_MOD_j]    = "j",
  72                 [FMT_MOD_t]    = "t",
  73                 [FMT_MOD_z]    = "z",
  74                 [FMT_MOD_q]    = "q",
  75                 /* only in microsoft mode */
  76                 [FMT_MOD_w]    = "w",
  77                 [FMT_MOD_I]    = "I",
  78                 [FMT_MOD_I32]  = "I32",
  79                 [FMT_MOD_I64]  = "I64"
  80         };
  81         assert(mod < sizeof(names) / sizeof(*names));
  82         return names[mod];
  83 }
  84
  85 static void warn_invalid_length_modifier(const source_position_t *pos,
  86                                          const format_length_modifier_t mod,
  87                                          const wchar_rep_t conversion)
  88 {
  89         warningf(pos,
  90                 "invalid length modifier '%s' for conversion specifier '%%%c'",
  91                 get_length_modifier_name(mod), conversion
  92         );
  93 }
  94
  95 typedef struct vchar_t vchar_t;
  96 struct vchar_t {
  97         const void *string;   /**< the string */
  98         size_t     position;  /**< current position */
  99         size_t     size;      /**< size of the string */
 100
 101         /** return the first character of the string and setthe position to 0. */
 102         unsigned (*first)(vchar_t *self);
 103         /** return the next character of the string */
 104         unsigned (*next)(vchar_t *self);
 105         /** return non_zero if the given character is a digit */
 106         int (*is_digit)(unsigned vchar);
 107 };
 108
 109 static unsigned string_first(vchar_t *self) {
 110         self->position = 0;
 111         const string_t *string = self->string;
 112         return string->begin[0];
 113 }
 114
 115 static unsigned string_next(vchar_t *self) {
 116         ++self->position;
 117         const string_t *string = self->string;
 118         return string->begin[self->position];
 119 }
 120
 121 static int string_isdigit(unsigned vchar) {
 122         return isdigit(vchar);
 123 }
 124
 125 static unsigned wstring_first(vchar_t *self) {
 126         self->position = 0;
 127         const wide_string_t *wstring = self->string;
 128         return wstring->begin[0];
 129 }
 130
 131 static unsigned wstring_next(vchar_t *self) {
 132         ++self->position;
 133         const wide_string_t *wstring = self->string;
 134         return wstring->begin[self->position];
 135 }
 136
 137 static int wstring_isdigit(unsigned vchar) {
 138         return iswdigit(vchar);
 139 }
 140
 141 static bool atend(vchar_t *self) {
 142         return self->position + 1 == self->size;
 143 }
 144
 145 /**
 146  * Check printf-style format.
 147  */
 148 static void check_format_arguments(const call_argument_t *arg, unsigned idx_fmt,
 149                 unsigned idx_param)
 150 {
 151         /* find format arg */
 152         unsigned idx = 0;
 153         for (; idx < idx_fmt; ++idx)
 154                 arg = arg->next;
 155
 156         const expression_t *fmt_expr = arg->expression;
 157         if (fmt_expr->kind == EXPR_UNARY_CAST_IMPLICIT) {
 158                 fmt_expr = fmt_expr->unary.value;
 159         }
 160
 161         vchar_t vchar;
 162         if (fmt_expr->kind == EXPR_WIDE_STRING_LITERAL) {
 163                 vchar.string   = &fmt_expr->wide_string.value;
 164                 vchar.size     = fmt_expr->wide_string.value.size;
 165                 vchar.first    = wstring_first;
 166                 vchar.next     = wstring_next;
 167                 vchar.is_digit = wstring_isdigit;
 168         } else if (fmt_expr->kind == EXPR_STRING_LITERAL) {
 169                 vchar.string   = &fmt_expr->string.value;
 170                 vchar.size     = fmt_expr->string.value.size;
 171                 vchar.first    = string_first;
 172                 vchar.next     = string_next;
 173                 vchar.is_digit = string_isdigit;
 174         } else {
 175                 return;
 176         }
 177         /* find the real args */
 178         for(; idx < idx_param; ++idx)
 179                 arg = arg->next;
 180
 181         const source_position_t *pos = &fmt_expr->base.source_position;
 182         unsigned fmt     = vchar.first(&vchar);
 183         unsigned num_fmt = 0;
 184         for (; fmt != '\0'; fmt = vchar.next(&vchar)) {
 185                 if (fmt != '%')
 186                         continue;
 187                 fmt = vchar.next(&vchar);
 188
 189                 if (fmt == '%')
 190                         continue;
 191
 192                 ++num_fmt;
 193
 194                 format_flags_t fmt_flags = FMT_FLAG_NONE;
 195                 if (fmt == '0') {
 196                         fmt = vchar.next(&vchar);
 197                         fmt_flags |= FMT_FLAG_ZERO;
 198                 }
 199
 200                 /* argument selector or minimum field width */
 201                 if (vchar.is_digit(fmt)) {
 202                         do {
 203                                 fmt = vchar.next(&vchar);
 204                         } while (vchar.is_digit(fmt));
 205
 206                         /* digit string was ... */
 207                         if (fmt == '$') {
 208                                 /* ... argument selector */
 209                                 fmt_flags = FMT_FLAG_NONE; /* reset possibly set 0-flag */
 210                                 /* TODO implement */
 211                                 return;
 212                         }
 213                         /* ... minimum field width */
 214                 } else {
 215                         /* flags */
 216                         for (;;) {
 217                                 format_flags_t flag;
 218                                 switch (fmt) {
 219                                         case '#':  flag = FMT_FLAG_HASH;  break;
 220                                         case '0':  flag = FMT_FLAG_ZERO;  break;
 221                                         case '-':  flag = FMT_FLAG_MINUS; break;
 222                                         case '\'': flag = FMT_FLAG_TICK;  break;
 223
 224                                         case ' ':
 225                                                 if (fmt_flags & FMT_FLAG_PLUS) {
 226                                                         warningf(pos, "' ' is overridden by prior '+' in conversion specification %u", num_fmt);
 227                                                 }
 228                                                 flag = FMT_FLAG_SPACE;
 229                                                 break;
 230
 231                                         case '+':
 232                                                 if (fmt_flags & FMT_FLAG_SPACE) {
 233                                                         warningf(pos, "'+' overrides prior ' ' in conversion specification %u", num_fmt);
 234                                                 }
 235                                                 flag = FMT_FLAG_PLUS;
 236                                                 break;
 237
 238                                         default: goto break_fmt_flags;
 239                                 }
 240                                 if (fmt_flags & flag) {
 241                                         warningf(pos, "repeated flag '%c' in conversion specification %u", (char)fmt, num_fmt);
 242                                 }
 243                                 fmt_flags |= flag;
 244                                 fmt = vchar.next(&vchar);
 245                         }
 246 break_fmt_flags:
 247
 248                         /* minimum field width */
 249                         if (fmt == '*') {
 250                                 fmt = vchar.next(&vchar);
 251                                 if (arg == NULL) {
 252                                         warningf(pos, "missing argument for '*' field width in conversion specification %u", num_fmt);
 253                                         return;
 254                                 }
 255                                 const type_t *const arg_type = arg->expression->base.type;
 256                                 if (arg_type != type_int) {
 257                                         warningf(pos, "argument for '*' field width in conversion specification %u is not an 'int', but an '%T'", num_fmt, arg_type);
 258                                 }
 259                                 arg = arg->next;
 260                         } else {
 261                                 while (vchar.is_digit(fmt)) {
 262                                         fmt = vchar.next(&vchar);
 263                                 }
 264                         }
 265                 }
 266
 267                 /* precision */
 268                 if (fmt == '.') {
 269                         fmt = vchar.next(&vchar);
 270                         if (fmt == '*') {
 271                                 fmt = vchar.next(&vchar);
 272                                 if (arg == NULL) {
 273                                         warningf(pos, "missing argument for '*' precision in conversion specification %u", num_fmt);
 274                                         return;
 275                                 }
 276                                 const type_t *const arg_type = arg->expression->base.type;
 277                                 if (arg_type != type_int) {
 278                                         warningf(pos, "argument for '*' precision in conversion specification %u is not an 'int', but an '%T'", num_fmt, arg_type);
 279                                 }
 280                                 arg = arg->next;
 281                         } else {
 282                                 /* digit string may be omitted */
 283                                 while (vchar.is_digit(fmt)) {
 284                                         fmt = vchar.next(&vchar);
 285                                 }
 286                         }
 287                 }
 288
 289                 /* length modifier */
 290                 format_length_modifier_t fmt_mod;
 291                 switch (fmt) {
 292                         case 'h':
 293                                 fmt = vchar.next(&vchar);
 294                                 if (fmt == 'h') {
 295                                         fmt = vchar.next(&vchar);
 296                                         fmt_mod = FMT_MOD_hh;
 297                                 } else {
 298                                         fmt_mod = FMT_MOD_h;
 299                                 }
 300                                 break;
 301
 302                         case 'l':
 303                                 fmt = vchar.next(&vchar);
 304                                 if (fmt == 'l') {
 305                                         fmt = vchar.next(&vchar);
 306                                         fmt_mod = FMT_MOD_ll;
 307                                 } else {
 308                                         fmt_mod = FMT_MOD_l;
 309                                 }
 310                                 break;
 311
 312                         case 'L': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_L;    break;
 313                         case 'j': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_j;    break;
 314                         case 't': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_t;    break;
 315                         case 'z': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_z;    break;
 316                         case 'q': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_q;    break;
 317                         /* microsoft mode */
 318                         case 'w':
 319                                 if (c_mode & _MS) {
 320                                         fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_w;
 321                                 } else {
 322                                         fmt_mod = FMT_MOD_NONE;
 323                                 }
 324                                 break;
 325                         case 'I':
 326                                 if (c_mode & _MS) {
 327                                         fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_I;
 328                                         if (fmt == '3') {
 329                                                 fmt = vchar.next(&vchar);
 330                                                 if (fmt == '2') {
 331                                                         fmt = vchar.next(&vchar);
 332                                                         fmt_mod = FMT_MOD_I32;
 333                                                 } else {
 334                                                         /* rewind */
 335                                                         --vchar.position;
 336                                                 }
 337                                         } else if (fmt == '6') {
 338                                                 fmt = vchar.next(&vchar);
 339                                                 if (fmt == '4') {
 340                                                         fmt = vchar.next(&vchar);
 341                                                         fmt_mod = FMT_MOD_I64;
 342                                                 } else {
 343                                                         /* rewind */
 344                                                         --vchar.position;
 345                                                 }
 346                                         }
 347                                 } else {
 348                                         fmt_mod = FMT_MOD_NONE;
 349                                 }
 350                                 break;
 351                         default:
 352                                 fmt_mod = FMT_MOD_NONE;
 353                                 break;
 354                 }
 355
 356                 if (fmt == '\0') {
 357                         warningf(pos, "dangling %% in format string");
 358                         break;
 359                 }
 360
 361                 type_t            *expected_type;
 362                 type_qualifiers_t  expected_qual = TYPE_QUALIFIER_NONE;
 363                 format_flags_t     allowed_flags;
 364                 switch (fmt) {
 365                         case 'd':
 366                         case 'i':
 367                                 switch (fmt_mod) {
 368                                         case FMT_MOD_NONE: expected_type = type_int;       break;
 369                                         case FMT_MOD_hh:   expected_type = type_int;       break; /* TODO promoted signed char */
 370                                         case FMT_MOD_h:    expected_type = type_int;       break; /* TODO promoted short */
 371                                         case FMT_MOD_l:    expected_type = type_long;      break;
 372                                         case FMT_MOD_ll:   expected_type = type_long_long; break;
 373                                         case FMT_MOD_j:    expected_type = type_intmax_t;  break;
 374                                         case FMT_MOD_z:    expected_type = type_ssize_t;   break;
 375                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t; break;
 376                                         case FMT_MOD_I:    expected_type = type_ptrdiff_t; break;
 377                                         case FMT_MOD_I32:  expected_type = type_int32;     break;
 378                                         case FMT_MOD_I64:  expected_type = type_int64;     break;
 379
 380                                         default:
 381                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 382                                                 goto next_arg;
 383                                 }
 384                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_ZERO;
 385                                 break;
 386
 387                         case 'o':
 388                         case 'X':
 389                         case 'x':
 390                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 391                                 goto eval_fmt_mod_unsigned;
 392                                 break;
 393
 394                         case 'u':
 395                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_ZERO;
 396 eval_fmt_mod_unsigned:
 397                                 switch (fmt_mod) {
 398                                         case FMT_MOD_NONE: expected_type = type_unsigned_int;       break;
 399                                         case FMT_MOD_hh:   expected_type = type_int;                break; /* TODO promoted unsigned char */
 400                                         case FMT_MOD_h:    expected_type = type_int;                break; /* TODO promoted unsigned short */
 401                                         case FMT_MOD_l:    expected_type = type_unsigned_long;      break;
 402                                         case FMT_MOD_ll:   expected_type = type_unsigned_long_long; break;
 403                                         case FMT_MOD_j:    expected_type = type_uintmax_t;          break;
 404                                         case FMT_MOD_z:    expected_type = type_size_t;             break;
 405                                         case FMT_MOD_t:    expected_type = type_uptrdiff_t;         break;
 406                                         case FMT_MOD_I:    expected_type = type_size_t;             break;
 407                                         case FMT_MOD_I32:  expected_type = type_unsigned_int32;     break;
 408                                         case FMT_MOD_I64:  expected_type = type_unsigned_int64;     break;
 409
 410                                         default:
 411                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 412                                                 goto next_arg;
 413                                 }
 414                                 break;
 415
 416                         case 'A':
 417                         case 'a':
 418                         case 'E':
 419                         case 'e':
 420                         case 'F':
 421                         case 'f':
 422                         case 'G':
 423                         case 'g':
 424                                 switch (fmt_mod) {
 425                                         case FMT_MOD_l:    /* l modifier is ignored */
 426                                         case FMT_MOD_NONE: expected_type = type_double;      break;
 427                                         case FMT_MOD_L:    expected_type = type_long_double; break;
 428
 429                                         default:
 430                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 431                                                 goto next_arg;
 432                                 }
 433                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 434                                 break;
 435
 436                         case 'C':
 437                                 if (fmt_mod != FMT_MOD_NONE) {
 438                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 439                                         goto next_arg;
 440                                 }
 441                                 expected_type = type_wchar_t;
 442                                 allowed_flags = FMT_FLAG_NONE;
 443                                 break;
 444
 445                         case 'c':
 446                                 expected_type = type_int;
 447                                 switch (fmt_mod) {
 448                                         case FMT_MOD_NONE: expected_type = type_int;     break; /* TODO promoted char */
 449                                         case FMT_MOD_l:    expected_type = type_wint_t;  break;
 450                                         case FMT_MOD_w:    expected_type = type_wchar_t; break;
 451
 452                                         default:
 453                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 454                                                 goto next_arg;
 455                                 }
 456                                 allowed_flags = FMT_FLAG_NONE;
 457                                 break;
 458
 459                         case 'S':
 460                                 if (fmt_mod != FMT_MOD_NONE) {
 461                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 462                                         goto next_arg;
 463                                 }
 464                                 expected_type = type_wchar_t_ptr;
 465                                 expected_qual = TYPE_QUALIFIER_CONST;
 466                                 allowed_flags = FMT_FLAG_MINUS;
 467                                 break;
 468
 469                         case 's':
 470                                 switch (fmt_mod) {
 471                                         case FMT_MOD_NONE: expected_type = type_char_ptr;    break;
 472                                         case FMT_MOD_l:    expected_type = type_wchar_t_ptr; break;
 473                                         case FMT_MOD_w:    expected_type = type_wchar_t_ptr; break;
 474
 475                                         default:
 476                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 477                                                 goto next_arg;
 478                                 }
 479                                 expected_qual = TYPE_QUALIFIER_CONST;
 480                                 allowed_flags = FMT_FLAG_MINUS;
 481                                 break;
 482
 483                         case 'p':
 484                                 if (fmt_mod != FMT_MOD_NONE) {
 485                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 486                                         goto next_arg;
 487                                 }
 488                                 expected_type = type_void_ptr;
 489                                 allowed_flags = FMT_FLAG_NONE;
 490                                 break;
 491
 492                         case 'n':
 493                                 switch (fmt_mod) {
 494                                         case FMT_MOD_NONE: expected_type = type_int_ptr;         break;
 495                                         case FMT_MOD_hh:   expected_type = type_signed_char_ptr; break;
 496                                         case FMT_MOD_h:    expected_type = type_short_ptr;       break;
 497                                         case FMT_MOD_l:    expected_type = type_long_ptr;        break;
 498                                         case FMT_MOD_ll:   expected_type = type_long_long_ptr;   break;
 499                                         case FMT_MOD_j:    expected_type = type_intmax_t_ptr;    break;
 500                                         case FMT_MOD_z:    expected_type = type_ssize_t_ptr;     break;
 501                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t_ptr;   break;
 502
 503                                         default:
 504                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 505                                                 goto next_arg;
 506                                 }
 507                                 allowed_flags = FMT_FLAG_NONE;
 508                                 break;
 509
 510                         default:
 511                                 warningf(pos, "encountered unknown conversion specifier '%%%C' at position %u", (wint_t)fmt, num_fmt);
 512                                 goto next_arg;
 513                 }
 514
 515                 format_flags_t wrong_flags = fmt_flags & ~allowed_flags;
 516                 if (wrong_flags != 0) {
 517                         char wrong[8];
 518                         int idx = 0;
 519                         if (wrong_flags & FMT_FLAG_HASH)  wrong[idx++] = '#';
 520                         if (wrong_flags & FMT_FLAG_ZERO)  wrong[idx++] = '0';
 521                         if (wrong_flags & FMT_FLAG_MINUS) wrong[idx++] = '-';
 522                         if (wrong_flags & FMT_FLAG_SPACE) wrong[idx++] = ' ';
 523                         if (wrong_flags & FMT_FLAG_PLUS)  wrong[idx++] = '+';
 524                         if (wrong_flags & FMT_FLAG_TICK)  wrong[idx++] = '\'';
 525                         wrong[idx] = '\0';
 526
 527                         warningf(pos, "invalid format flags \"%s\" in conversion specification %%%c at position", wrong, fmt, num_fmt);
 528                 }
 529
 530                 if (arg == NULL) {
 531                         warningf(pos, "too few arguments for format string");
 532                         return;
 533                 }
 534
 535                 {       /* create a scope here to prevent warning about the jump to next_arg */
 536                         type_t *const arg_type           = arg->expression->base.type;
 537                         type_t *const arg_skip           = skip_typeref(arg_type);
 538                         type_t *const expected_type_skip = skip_typeref(expected_type);
 539                         if (is_type_pointer(expected_type_skip)) {
 540                                 if (is_type_pointer(arg_skip)) {
 541                                         type_t *const exp_to = skip_typeref(expected_type_skip->pointer.points_to);
 542                                         type_t *const arg_to = skip_typeref(arg_skip->pointer.points_to);
 543                                         if ((arg_to->base.qualifiers & ~expected_qual) == 0 &&
 544                                                 get_unqualified_type(arg_to) == exp_to) {
 545                                                 goto next_arg;
 546                                         }
 547                                 }
 548                         } else {
 549                                 if (get_unqualified_type(arg_skip) == expected_type_skip) {
 550                                         goto next_arg;
 551                                 }
 552                         }
 553                         if (is_type_valid(arg_skip)) {
 554                                 warningf(pos,
 555                                         "argument type '%T' does not match conversion specifier '%%%s%c' at position",
 556                                         arg_type, get_length_modifier_name(fmt_mod), (char)fmt, num_fmt);
 557                         }
 558                 }
 559 next_arg:
 560                 arg = arg->next;
 561         }
 562         if (!atend(&vchar)) {
 563                 warningf(pos, "format string contains NUL");
 564         }
 565         if (arg != NULL) {
 566                 unsigned num_args = num_fmt;
 567                 while (arg != NULL) {
 568                         ++num_args;
 569                         arg = arg->next;
 570                 }
 571                 warningf(pos, "%u argument%s but only %u format string%s",
 572                         num_args, num_args != 1 ? "s" : "",
 573                         num_fmt, num_fmt != 1 ? "s" : "");
 574         }
 575 }
 576
 577 static const struct {
 578         const char    *name;
 579         format_kind_t  fmt_kind;
 580         unsigned       fmt_idx;
 581         unsigned       arg_idx;
 582 } builtin_table[] = {
 583         { "printf",        FORMAT_PRINTF,   0, 1 },
 584         { "wprintf",       FORMAT_PRINTF,   0, 1 },
 585         { "sprintf",       FORMAT_PRINTF,   1, 2 },
 586         { "swprintf",      FORMAT_PRINTF,   1, 2 },
 587         { "snprintf",      FORMAT_PRINTF,   2, 3 },
 588         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 589         { "fprintf",       FORMAT_PRINTF,   1, 2 },
 590         { "fwprintf",      FORMAT_PRINTF,   1, 2 },
 591         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 592         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 593
 594         { "scanf",         FORMAT_SCANF,    0, 1 },
 595         { "wscanf",        FORMAT_SCANF,    0, 1 },
 596         { "sscanf",        FORMAT_SCANF,    1, 2 },
 597         { "swscanf",       FORMAT_SCANF,    1, 2 },
 598         { "fscanf",        FORMAT_SCANF,    1, 2 },
 599         { "fwscanf",       FORMAT_SCANF,    1, 2 },
 600
 601         { "strftime",      FORMAT_STRFTIME, 3, 4 },
 602         { "wcstrftime",    FORMAT_STRFTIME, 3, 4 },
 603
 604         { "strfmon",       FORMAT_STRFMON,  3, 4 },
 605
 606         /* MS extensions */
 607         { "_snprintf",     FORMAT_PRINTF,   2, 3 },
 608         { "_snwprintf",    FORMAT_PRINTF,   2, 3 },
 609         { "_scrintf",      FORMAT_PRINTF,   0, 1 },
 610         { "_scwprintf",    FORMAT_PRINTF,   0, 1 },
 611         { "printf_s",      FORMAT_PRINTF,   0, 1 },
 612         { "wprintf_s",     FORMAT_PRINTF,   0, 1 },
 613         { "sprintf_s",     FORMAT_PRINTF,   3, 4 },
 614         { "swprintf_s",    FORMAT_PRINTF,   3, 4 },
 615         { "fprintf_s",     FORMAT_PRINTF,   1, 2 },
 616         { "fwprintf_s",    FORMAT_PRINTF,   1, 2 },
 617         { "_sprintf_l",    FORMAT_PRINTF,   1, 3 },
 618         { "_swprintf_l",   FORMAT_PRINTF,   1, 3 },
 619         { "_printf_l",     FORMAT_PRINTF,   0, 2 },
 620         { "_wprintf_l",    FORMAT_PRINTF,   0, 2 },
 621         { "_fprintf_l",    FORMAT_PRINTF,   1, 3 },
 622         { "_fwprintf_l",   FORMAT_PRINTF,   1, 3 },
 623         { "_printf_s_l",   FORMAT_PRINTF,   0, 2 },
 624         { "_wprintf_s_l",  FORMAT_PRINTF,   0, 2 },
 625         { "_sprintf_s_l",  FORMAT_PRINTF,   3, 5 },
 626         { "_swprintf_s_l", FORMAT_PRINTF,   3, 5 },
 627         { "_fprintf_s_l",  FORMAT_PRINTF,   1, 3 },
 628         { "_fwprintf_s_l", FORMAT_PRINTF,   1, 3 },
 629 };
 630
 631 void check_format(const call_expression_t *const call)
 632 {
 633         if (!warning.format)
 634                 return;
 635
 636         const expression_t *const func_expr = call->function;
 637         if (func_expr->kind != EXPR_REFERENCE)
 638                 return;
 639
 640         const declaration_t   *const decl = func_expr->reference.declaration;
 641         const call_argument_t *      arg  = call->arguments;
 642
 643         if(false) {
 644                 /* the declaration has a GNU format attribute, check it */
 645         } else {
 646                 /*
 647                  * For some functions we always check the format, even if it was not specified.
 648                  * This allows to check format even in MS mode or without header included.
 649                  */
 650                 const char            *const name = decl->symbol->string;
 651                 for(size_t i = 0; i < sizeof(builtin_table) / sizeof(builtin_table[0]); ++i) {
 652                         if(strcmp(name, builtin_table[i].name) == 0) {
 653                                 if(builtin_table[i].fmt_kind == FORMAT_PRINTF) {
 654                                         check_format_arguments(arg,
 655                                                                builtin_table[i].fmt_idx,
 656                                                                builtin_table[i].arg_idx);
 657                                 }
 658                                 break;
 659                         }
 660                 }
 661         }
 662 }