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         const call_argument_t *fmt_arg;
 152         unsigned num_fmt = 0;
 153
 154         /* find format arg */
 155         unsigned idx = 0;
 156         for (; idx < idx_fmt; ++idx)
 157                 arg = arg->next;
 158         fmt_arg = arg;
 159
 160         const expression_t *fmt_expr = fmt_arg->expression;
 161         if (fmt_expr->kind == EXPR_UNARY_CAST_IMPLICIT) {
 162                 fmt_expr = fmt_expr->unary.value;
 163         }
 164
 165         vchar_t vchar;
 166         if (fmt_expr->kind == EXPR_WIDE_STRING_LITERAL) {
 167                 vchar.string   = &fmt_expr->wide_string.value;
 168                 vchar.size     = fmt_expr->wide_string.value.size;
 169                 vchar.first    = wstring_first;
 170                 vchar.next     = wstring_next;
 171                 vchar.is_digit = wstring_isdigit;
 172         } else if (fmt_expr->kind == EXPR_STRING_LITERAL) {
 173                 vchar.string   = &fmt_expr->string.value;
 174                 vchar.size     = fmt_expr->string.value.size;
 175                 vchar.first    = string_first;
 176                 vchar.next     = string_next;
 177                 vchar.is_digit = string_isdigit;
 178         } else {
 179                 return;
 180         }
 181         /* find the real args */
 182         for(; idx < idx_param; ++idx)
 183                 arg = arg->next;
 184
 185         const source_position_t *pos = &fmt_expr->base.source_position;
 186         unsigned fmt = vchar.first(&vchar);
 187         for (; fmt != '\0'; fmt = vchar.next(&vchar)) {
 188                 if (fmt != '%')
 189                         continue;
 190                 fmt = vchar.next(&vchar);
 191
 192                 if (fmt == '%')
 193                         continue;
 194
 195                 ++num_fmt;
 196
 197                 format_flags_t fmt_flags = FMT_FLAG_NONE;
 198                 if (fmt == '0') {
 199                         fmt = vchar.next(&vchar);
 200                         fmt_flags |= FMT_FLAG_ZERO;
 201                 }
 202
 203                 /* argument selector or minimum field width */
 204                 if (vchar.is_digit(fmt)) {
 205                         do {
 206                                 fmt = vchar.next(&vchar);
 207                         } while (vchar.is_digit(fmt));
 208
 209                         /* digit string was ... */
 210                         if (fmt == '$') {
 211                                 /* ... argument selector */
 212                                 fmt_flags = FMT_FLAG_NONE; /* reset possibly set 0-flag */
 213                                 /* TODO implement */
 214                                 return;
 215                         }
 216                         /* ... minimum field width */
 217                 } else {
 218                         /* flags */
 219                         for (;;) {
 220                                 format_flags_t flag;
 221                                 switch (fmt) {
 222                                         case '#':  flag = FMT_FLAG_HASH;  break;
 223                                         case '0':  flag = FMT_FLAG_ZERO;  break;
 224                                         case '-':  flag = FMT_FLAG_MINUS; break;
 225                                         case '\'': flag = FMT_FLAG_TICK;  break;
 226
 227                                         case ' ':
 228                                                 if (fmt_flags & FMT_FLAG_PLUS) {
 229                                                         warningf(pos, "' ' is overridden by prior '+' in conversion specification");
 230                                                 }
 231                                                 flag = FMT_FLAG_SPACE;
 232                                                 break;
 233
 234                                         case '+':
 235                                                 if (fmt_flags & FMT_FLAG_SPACE) {
 236                                                         warningf(pos, "'+' overrides prior ' ' in conversion specification");
 237                                                 }
 238                                                 flag = FMT_FLAG_PLUS;
 239                                                 break;
 240
 241                                         default: goto break_fmt_flags;
 242                                 }
 243                                 if (fmt_flags & flag) {
 244                                         warningf(pos, "repeated flag '%c' in conversion specification", (char)fmt);
 245                                 }
 246                                 fmt_flags |= flag;
 247                                 fmt = vchar.next(&vchar);
 248                         }
 249 break_fmt_flags:
 250
 251                         /* minimum field width */
 252                         if (fmt == '*') {
 253                                 fmt = vchar.next(&vchar);
 254                                 if (arg == NULL) {
 255                                         warningf(pos, "missing argument for '*' field width in conversion specification");
 256                                         return;
 257                                 }
 258                                 const type_t *const arg_type = arg->expression->base.type;
 259                                 if (arg_type != type_int) {
 260                                         warningf(pos, "argument for '*' field width in conversion specification is not an 'int', but an '%T'", arg_type);
 261                                 }
 262                                 arg = arg->next;
 263                         } else {
 264                                 while (vchar.is_digit(fmt)) {
 265                                         fmt = vchar.next(&vchar);
 266                                 }
 267                         }
 268                 }
 269
 270                 /* precision */
 271                 if (fmt == '.') {
 272                         fmt = vchar.next(&vchar);
 273                         if (fmt == '*') {
 274                                 fmt = vchar.next(&vchar);
 275                                 if (arg == NULL) {
 276                                         warningf(pos, "missing argument for '*' precision in conversion specification");
 277                                         return;
 278                                 }
 279                                 const type_t *const arg_type = arg->expression->base.type;
 280                                 if (arg_type != type_int) {
 281                                         warningf(pos, "argument for '*' precision in conversion specification is not an 'int', but an '%T'", arg_type);
 282                                 }
 283                                 arg = arg->next;
 284                         } else {
 285                                 /* digit string may be omitted */
 286                                 while (vchar.is_digit(fmt)) {
 287                                         fmt = vchar.next(&vchar);
 288                                 }
 289                         }
 290                 }
 291
 292                 /* length modifier */
 293                 format_length_modifier_t fmt_mod;
 294                 switch (fmt) {
 295                         case 'h':
 296                                 fmt = vchar.next(&vchar);
 297                                 if (fmt == 'h') {
 298                                         fmt = vchar.next(&vchar);
 299                                         fmt_mod = FMT_MOD_hh;
 300                                 } else {
 301                                         fmt_mod = FMT_MOD_h;
 302                                 }
 303                                 break;
 304
 305                         case 'l':
 306                                 fmt = vchar.next(&vchar);
 307                                 if (fmt == 'l') {
 308                                         fmt = vchar.next(&vchar);
 309                                         fmt_mod = FMT_MOD_ll;
 310                                 } else {
 311                                         fmt_mod = FMT_MOD_l;
 312                                 }
 313                                 break;
 314
 315                         case 'L': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_L;    break;
 316                         case 'j': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_j;    break;
 317                         case 't': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_t;    break;
 318                         case 'z': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_z;    break;
 319                         case 'q': fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_q;    break;
 320                         /* microsoft mode */
 321                         case 'w':
 322                                 if (c_mode & _MS) {
 323                                         fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_w;
 324                                 } else {
 325                                         fmt_mod = FMT_MOD_NONE;
 326                                 }
 327                                 break;
 328                         case 'I':
 329                                 if (c_mode & _MS) {
 330                                         fmt = vchar.next(&vchar); fmt_mod = FMT_MOD_I;
 331                                         if (fmt == '3') {
 332                                                 fmt = vchar.next(&vchar);
 333                                                 if (fmt == '2') {
 334                                                         fmt = vchar.next(&vchar);
 335                                                         fmt_mod = FMT_MOD_I32;
 336                                                 } else {
 337                                                         /* rewind */
 338                                                         --vchar.position;
 339                                                 }
 340                                         } else if (fmt == '6') {
 341                                                 fmt = vchar.next(&vchar);
 342                                                 if (fmt == '4') {
 343                                                         fmt = vchar.next(&vchar);
 344                                                         fmt_mod = FMT_MOD_I64;
 345                                                 } else {
 346                                                         /* rewind */
 347                                                         --vchar.position;
 348                                                 }
 349                                         }
 350                                 } else {
 351                                         fmt_mod = FMT_MOD_NONE;
 352                                 }
 353                                 break;
 354                         default:
 355                                 fmt_mod = FMT_MOD_NONE;
 356                                 break;
 357                 }
 358
 359                 if (fmt == '\0') {
 360                         warningf(pos, "dangling %% in format string");
 361                         break;
 362                 }
 363
 364                 type_t            *expected_type;
 365                 type_qualifiers_t  expected_qual = TYPE_QUALIFIER_NONE;
 366                 format_flags_t     allowed_flags;
 367                 switch (fmt) {
 368                         case 'd':
 369                         case 'i':
 370                                 switch (fmt_mod) {
 371                                         case FMT_MOD_NONE: expected_type = type_int;       break;
 372                                         case FMT_MOD_hh:   expected_type = type_int;       break; /* TODO promoted signed char */
 373                                         case FMT_MOD_h:    expected_type = type_int;       break; /* TODO promoted short */
 374                                         case FMT_MOD_l:    expected_type = type_long;      break;
 375                                         case FMT_MOD_ll:   expected_type = type_long_long; break;
 376                                         case FMT_MOD_j:    expected_type = type_intmax_t;  break;
 377                                         case FMT_MOD_z:    expected_type = type_ssize_t;   break;
 378                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t; break;
 379                                         case FMT_MOD_I:    expected_type = type_ptrdiff_t; break;
 380                                         case FMT_MOD_I32:  expected_type = type_int32;     break;
 381                                         case FMT_MOD_I64:  expected_type = type_int64;     break;
 382
 383                                         default:
 384                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 385                                                 goto next_arg;
 386                                 }
 387                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_ZERO;
 388                                 break;
 389
 390                         case 'o':
 391                         case 'X':
 392                         case 'x':
 393                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 394                                 goto eval_fmt_mod_unsigned;
 395                                 break;
 396
 397                         case 'u':
 398                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_ZERO;
 399 eval_fmt_mod_unsigned:
 400                                 switch (fmt_mod) {
 401                                         case FMT_MOD_NONE: expected_type = type_unsigned_int;       break;
 402                                         case FMT_MOD_hh:   expected_type = type_int;                break; /* TODO promoted unsigned char */
 403                                         case FMT_MOD_h:    expected_type = type_int;                break; /* TODO promoted unsigned short */
 404                                         case FMT_MOD_l:    expected_type = type_unsigned_long;      break;
 405                                         case FMT_MOD_ll:   expected_type = type_unsigned_long_long; break;
 406                                         case FMT_MOD_j:    expected_type = type_uintmax_t;          break;
 407                                         case FMT_MOD_z:    expected_type = type_size_t;             break;
 408                                         case FMT_MOD_t:    expected_type = type_uptrdiff_t;         break;
 409                                         case FMT_MOD_I:    expected_type = type_size_t;             break;
 410                                         case FMT_MOD_I32:  expected_type = type_unsigned_int32;     break;
 411                                         case FMT_MOD_I64:  expected_type = type_unsigned_int64;     break;
 412
 413                                         default:
 414                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 415                                                 goto next_arg;
 416                                 }
 417                                 break;
 418
 419                         case 'A':
 420                         case 'a':
 421                         case 'E':
 422                         case 'e':
 423                         case 'F':
 424                         case 'f':
 425                         case 'G':
 426                         case 'g':
 427                                 switch (fmt_mod) {
 428                                         case FMT_MOD_l:    /* l modifier is ignored */
 429                                         case FMT_MOD_NONE: expected_type = type_double;      break;
 430                                         case FMT_MOD_L:    expected_type = type_long_double; break;
 431
 432                                         default:
 433                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 434                                                 goto next_arg;
 435                                 }
 436                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 437                                 break;
 438
 439                         case 'C':
 440                                 if (fmt_mod != FMT_MOD_NONE) {
 441                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 442                                         goto next_arg;
 443                                 }
 444                                 expected_type = type_wchar_t;
 445                                 allowed_flags = FMT_FLAG_NONE;
 446                                 break;
 447
 448                         case 'c':
 449                                 expected_type = type_int;
 450                                 switch (fmt_mod) {
 451                                         case FMT_MOD_NONE: expected_type = type_int;     break; /* TODO promoted char */
 452                                         case FMT_MOD_l:    expected_type = type_wint_t;  break;
 453                                         case FMT_MOD_w:    expected_type = type_wchar_t; break;
 454
 455                                         default:
 456                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 457                                                 goto next_arg;
 458                                 }
 459                                 allowed_flags = FMT_FLAG_NONE;
 460                                 break;
 461
 462                         case 'S':
 463                                 if (fmt_mod != FMT_MOD_NONE) {
 464                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 465                                         goto next_arg;
 466                                 }
 467                                 expected_type = type_wchar_t_ptr;
 468                                 expected_qual = TYPE_QUALIFIER_CONST;
 469                                 allowed_flags = FMT_FLAG_MINUS;
 470                                 break;
 471
 472                         case 's':
 473                                 switch (fmt_mod) {
 474                                         case FMT_MOD_NONE: expected_type = type_char_ptr;    break;
 475                                         case FMT_MOD_l:    expected_type = type_wchar_t_ptr; break;
 476                                         case FMT_MOD_w:    expected_type = type_wchar_t_ptr; break;
 477
 478                                         default:
 479                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 480                                                 goto next_arg;
 481                                 }
 482                                 expected_qual = TYPE_QUALIFIER_CONST;
 483                                 allowed_flags = FMT_FLAG_MINUS;
 484                                 break;
 485
 486                         case 'p':
 487                                 if (fmt_mod != FMT_MOD_NONE) {
 488                                         warn_invalid_length_modifier(pos, fmt_mod, fmt);
 489                                         goto next_arg;
 490                                 }
 491                                 expected_type = type_void_ptr;
 492                                 allowed_flags = FMT_FLAG_NONE;
 493                                 break;
 494
 495                         case 'n':
 496                                 switch (fmt_mod) {
 497                                         case FMT_MOD_NONE: expected_type = type_int_ptr;         break;
 498                                         case FMT_MOD_hh:   expected_type = type_signed_char_ptr; break;
 499                                         case FMT_MOD_h:    expected_type = type_short_ptr;       break;
 500                                         case FMT_MOD_l:    expected_type = type_long_ptr;        break;
 501                                         case FMT_MOD_ll:   expected_type = type_long_long_ptr;   break;
 502                                         case FMT_MOD_j:    expected_type = type_intmax_t_ptr;    break;
 503                                         case FMT_MOD_z:    expected_type = type_ssize_t_ptr;     break;
 504                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t_ptr;   break;
 505
 506                                         default:
 507                                                 warn_invalid_length_modifier(pos, fmt_mod, fmt);
 508                                                 goto next_arg;
 509                                 }
 510                                 allowed_flags = FMT_FLAG_NONE;
 511                                 break;
 512
 513                         default:
 514                                 warningf(pos, "encountered unknown conversion specifier '%%%C'", (wint_t)fmt);
 515                                 goto next_arg;
 516                 }
 517
 518                 format_flags_t wrong_flags = fmt_flags & ~allowed_flags;
 519                 if (wrong_flags != 0) {
 520                         char wrong[8];
 521                         int idx = 0;
 522                         if (wrong_flags & FMT_FLAG_HASH)  wrong[idx++] = '#';
 523                         if (wrong_flags & FMT_FLAG_ZERO)  wrong[idx++] = '0';
 524                         if (wrong_flags & FMT_FLAG_MINUS) wrong[idx++] = '-';
 525                         if (wrong_flags & FMT_FLAG_SPACE) wrong[idx++] = ' ';
 526                         if (wrong_flags & FMT_FLAG_PLUS)  wrong[idx++] = '+';
 527                         if (wrong_flags & FMT_FLAG_TICK)  wrong[idx++] = '\'';
 528                         wrong[idx] = '\0';
 529
 530                         warningf(pos, "invalid format flags \"%s\" in conversion specification %%%c", wrong, fmt);
 531                 }
 532
 533                 if (arg == NULL) {
 534                         warningf(pos, "too few arguments for format string");
 535                         return;
 536                 }
 537
 538                 {       /* create a scope here to prevent warning about the jump to next_arg */
 539                         type_t *const arg_type           = arg->expression->base.type;
 540                         type_t *const arg_skip           = skip_typeref(arg_type);
 541                         type_t *const expected_type_skip = skip_typeref(expected_type);
 542                         if (is_type_pointer(expected_type_skip)) {
 543                                 if (is_type_pointer(arg_skip)) {
 544                                         type_t *const exp_to = skip_typeref(expected_type_skip->pointer.points_to);
 545                                         type_t *const arg_to = skip_typeref(arg_skip->pointer.points_to);
 546                                         if ((arg_to->base.qualifiers & ~expected_qual) == 0 &&
 547                                                 get_unqualified_type(arg_to) == exp_to) {
 548                                                 goto next_arg;
 549                                         }
 550                                 }
 551                         } else {
 552                                 if (get_unqualified_type(arg_skip) == expected_type_skip) {
 553                                         goto next_arg;
 554                                 }
 555                         }
 556                         if (is_type_valid(arg_skip)) {
 557                                 warningf(pos,
 558                                         "argument type '%T' does not match conversion specifier '%%%s%c'",
 559                                         arg_type, get_length_modifier_name(fmt_mod), (char)fmt);
 560                         }
 561                 }
 562 next_arg:
 563                 arg = arg->next;
 564         }
 565         if (!atend(&vchar)) {
 566                 warningf(pos, "format string contains NUL");
 567         }
 568         if (arg != NULL) {
 569                 unsigned num_args = num_fmt;
 570                 while (arg != NULL) {
 571                         ++num_args;
 572                         arg = arg->next;
 573                 }
 574                 warningf(pos, "%u argument%s but only %u format string%s",
 575                         num_args, num_args != 1 ? "s" : "",
 576                         num_fmt, num_fmt != 1 ? "s" : "");
 577         }
 578 }
 579
 580 static const struct {
 581         const char    *name;
 582         format_kind_t  fmt_kind;
 583         unsigned       fmt_idx;
 584         unsigned       arg_idx;
 585 } builtin_table[] = {
 586         { "printf",        FORMAT_PRINTF,   0, 1 },
 587         { "wprintf",       FORMAT_PRINTF,   0, 1 },
 588         { "sprintf",       FORMAT_PRINTF,   1, 2 },
 589         { "swprintf",      FORMAT_PRINTF,   1, 2 },
 590         { "snprintf",      FORMAT_PRINTF,   2, 3 },
 591         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 592         { "fprintf",       FORMAT_PRINTF,   1, 2 },
 593         { "fwprintf",      FORMAT_PRINTF,   1, 2 },
 594         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 595         { "snwprintf",     FORMAT_PRINTF,   2, 3 },
 596
 597         { "scanf",         FORMAT_SCANF,    0, 1 },
 598         { "wscanf",        FORMAT_SCANF,    0, 1 },
 599         { "sscanf",        FORMAT_SCANF,    1, 2 },
 600         { "swscanf",       FORMAT_SCANF,    1, 2 },
 601         { "fscanf",        FORMAT_SCANF,    1, 2 },
 602         { "fwscanf",       FORMAT_SCANF,    1, 2 },
 603
 604         { "strftime",      FORMAT_STRFTIME, 3, 4 },
 605         { "wcstrftime",    FORMAT_STRFTIME, 3, 4 },
 606
 607         { "strfmon",       FORMAT_STRFMON,  3, 4 },
 608
 609         /* MS extensions */
 610         { "_snprintf",     FORMAT_PRINTF,   2, 3 },
 611         { "_snwprintf",    FORMAT_PRINTF,   2, 3 },
 612         { "_scrintf",      FORMAT_PRINTF,   0, 1 },
 613         { "_scwprintf",    FORMAT_PRINTF,   0, 1 },
 614         { "printf_s",      FORMAT_PRINTF,   0, 1 },
 615         { "wprintf_s",     FORMAT_PRINTF,   0, 1 },
 616         { "sprintf_s",     FORMAT_PRINTF,   3, 4 },
 617         { "swprintf_s",    FORMAT_PRINTF,   3, 4 },
 618         { "fprintf_s",     FORMAT_PRINTF,   1, 2 },
 619         { "fwprintf_s",    FORMAT_PRINTF,   1, 2 },
 620         { "_sprintf_l",    FORMAT_PRINTF,   1, 3 },
 621         { "_swprintf_l",   FORMAT_PRINTF,   1, 3 },
 622         { "_printf_l",     FORMAT_PRINTF,   0, 2 },
 623         { "_wprintf_l",    FORMAT_PRINTF,   0, 2 },
 624         { "_fprintf_l",    FORMAT_PRINTF,   1, 3 },
 625         { "_fwprintf_l",   FORMAT_PRINTF,   1, 3 },
 626         { "_printf_s_l",   FORMAT_PRINTF,   0, 2 },
 627         { "_wprintf_s_l",  FORMAT_PRINTF,   0, 2 },
 628         { "_sprintf_s_l",  FORMAT_PRINTF,   3, 5 },
 629         { "_swprintf_s_l", FORMAT_PRINTF,   3, 5 },
 630         { "_fprintf_s_l",  FORMAT_PRINTF,   1, 3 },
 631         { "_fwprintf_s_l", FORMAT_PRINTF,   1, 3 },
 632 };
 633
 634 void check_format(const call_expression_t *const call)
 635 {
 636         if (!warning.format)
 637                 return;
 638
 639         const expression_t *const func_expr = call->function;
 640         if (func_expr->kind != EXPR_REFERENCE)
 641                 return;
 642
 643         const declaration_t   *const decl = func_expr->reference.declaration;
 644         const call_argument_t *      arg  = call->arguments;
 645
 646         if(false) {
 647                 /* the declaration has a GNU format attribute, check it */
 648         } else {
 649                 /*
 650                  * For some functions we always check the format, even if it was not specified.
 651                  * This allows to check format even in MS mode or without header included.
 652                  */
 653                 const char            *const name = decl->symbol->string;
 654                 for(size_t i = 0; i < sizeof(builtin_table) / sizeof(builtin_table[0]); ++i) {
 655                         if(strcmp(name, builtin_table[i].name) == 0) {
 656                                 if(builtin_table[i].fmt_kind == FORMAT_PRINTF) {
 657                                         check_format_arguments(arg,
 658                                                                builtin_table[i].fmt_idx,
 659                                                                builtin_table[i].arg_idx);
 660                                 }
 661                                 break;
 662                         }
 663                 }
 664         }
 665 }