nsz Git - cparser/blob - format_check.c

   1 #include <wctype.h>
   2
   3 #include "ast_t.h"
   4 #include "diagnostic.h"
   5 #include "format_check.h"
   6 #include "types.h"
   7 #include "type_t.h"
   8
   9
  10 typedef enum format_flag_t {
  11         FMT_FLAG_NONE  = 0,
  12         FMT_FLAG_HASH  = 1U << 0,
  13         FMT_FLAG_ZERO  = 1U << 1,
  14         FMT_FLAG_MINUS = 1U << 2,
  15         FMT_FLAG_SPACE = 1U << 3,
  16         FMT_FLAG_PLUS  = 1U << 4,
  17         FMT_FLAG_TICK  = 1U << 5
  18 } format_flag_t;
  19
  20 typedef unsigned format_flags_t;
  21
  22 typedef enum format_length_modifier_t {
  23         FMT_MOD_NONE,
  24         FMT_MOD_L,
  25         FMT_MOD_hh,
  26         FMT_MOD_h,
  27         FMT_MOD_l,
  28         FMT_MOD_ll,
  29         FMT_MOD_j,
  30         FMT_MOD_t,
  31         FMT_MOD_z,
  32         FMT_MOD_q
  33 } format_length_modifier_t;
  34
  35 static const char* get_length_modifier_name(const format_length_modifier_t mod)
  36 {
  37         static const char* const names[] = {
  38                 [FMT_MOD_NONE] = "",
  39                 [FMT_MOD_L]    = "L",
  40                 [FMT_MOD_hh]   = "hh",
  41                 [FMT_MOD_h]    = "h",
  42                 [FMT_MOD_l]    = "l",
  43                 [FMT_MOD_ll]   = "ll",
  44                 [FMT_MOD_j]    = "j",
  45                 [FMT_MOD_t]    = "t",
  46                 [FMT_MOD_z]    = "z",
  47                 [FMT_MOD_q]    = "q"
  48         };
  49         assert(mod < sizeof(names) / sizeof(*names));
  50         return names[mod];
  51 }
  52
  53 static void warn_invalid_length_modifier(const source_position_t pos,
  54                                          const format_length_modifier_t mod,
  55                                          const wchar_rep_t conversion)
  56 {
  57         warningf(pos,
  58                 "invalid length modifier '%s' for conversion specifier '%%%c'",
  59                 get_length_modifier_name(mod), conversion
  60         );
  61 }
  62
  63 static void check_format_arguments(const call_argument_t *const fmt_arg, const call_argument_t* arg)
  64 {
  65         const expression_t *fmt_expr = fmt_arg->expression;
  66         if (fmt_expr->kind == EXPR_UNARY_CAST_IMPLICIT) {
  67                 fmt_expr = fmt_expr->unary.value;
  68         }
  69
  70         if (fmt_expr->kind != EXPR_WIDE_STRING_LITERAL)
  71                 return;
  72
  73         const source_position_t    pos     = fmt_expr->base.source_position;
  74         const wide_string_t *const wstring = &fmt_expr->wide_string.value;
  75         const wchar_rep_t *fmt = wstring->begin;
  76         for (; *fmt != '\0'; ++fmt) {
  77                 if (*fmt != '%')
  78                         continue;
  79                 ++fmt;
  80
  81                 if (*fmt == '%')
  82                         continue;
  83
  84                 format_flags_t fmt_flags = FMT_FLAG_NONE;
  85                 if (*fmt == '0') {
  86                         ++fmt;
  87                         fmt_flags |= FMT_FLAG_ZERO;
  88                 }
  89
  90                 /* argument selector or minimum field width */
  91                 if (iswdigit(*fmt)) {
  92                         do {
  93                                 ++fmt;
  94                         } while (iswdigit(*fmt));
  95
  96                         /* digit string was ... */
  97                         if (*fmt == '$') {
  98                                 /* ... argument selector */
  99                                 fmt_flags = FMT_FLAG_NONE; /* reset possibly set 0-flag */
 100                                 /* TODO implement */
 101                                 return;
 102                         }
 103                         /* ... minimum field width */
 104                 } else {
 105                         /* flags */
 106                         for (;;) {
 107                                 format_flags_t flag;
 108                                 switch (*fmt) {
 109                                         case '#':  flag = FMT_FLAG_HASH;  break;
 110                                         case '0':  flag = FMT_FLAG_ZERO;  break;
 111                                         case '-':  flag = FMT_FLAG_MINUS; break;
 112                                         case '\'': flag = FMT_FLAG_TICK;  break;
 113
 114                                         case ' ':
 115                                                 if (fmt_flags & FMT_FLAG_PLUS) {
 116                                                         warningf(pos, "' ' is overridden by prior '+' in conversion specification");
 117                                                 }
 118                                                 flag = FMT_FLAG_SPACE;
 119                                                 break;
 120
 121                                         case '+':
 122                                                 if (fmt_flags & FMT_FLAG_SPACE) {
 123                                                         warningf(pos, "'+' overrides prior ' ' in conversion specification");
 124                                                 }
 125                                                 flag = FMT_FLAG_PLUS;
 126                                                 break;
 127
 128                                         default: goto break_fmt_flags;
 129                                 }
 130                                 if (fmt_flags & flag) {
 131                                         warningf(pos, "repeated flag '%c' in conversion specification", (char)*fmt);
 132                                 }
 133                                 fmt_flags |= flag;
 134                                 ++fmt;
 135                         }
 136 break_fmt_flags:
 137
 138                         /* minimum field width */
 139                         if (*fmt == '*') {
 140                                 if (arg == NULL) {
 141                                         warningf(pos, "missing argument for '*' field width in conversion specification");
 142                                         return;
 143                                 }
 144                                 const type_t *const arg_type = arg->expression->base.datatype;
 145                                 if (arg_type != type_int) {
 146                                         warningf(pos, "argument for '*' field width in conversion specification is not an 'int', but an '%T'", arg_type);
 147                                 }
 148                                 arg = arg->next;
 149                         } else {
 150                                 while (iswdigit(*fmt)) {
 151                                         ++fmt;
 152                                 }
 153                         }
 154                 }
 155
 156                 /* precision */
 157                 if (*fmt == '.') {
 158                         ++fmt;
 159                         if (*fmt == '*') {
 160                                 if (arg == NULL) {
 161                                         warningf(pos, "missing argument for '*' precision in conversion specification");
 162                                         return;
 163                                 }
 164                                 const type_t *const arg_type = arg->expression->base.datatype;
 165                                 if (arg_type != type_int) {
 166                                         warningf(pos, "argument for '*' precision in conversion specification is not an 'int', but an '%T'", arg_type);
 167                                 }
 168                                 arg = arg->next;
 169                         } else {
 170                                 /* digit string may be omitted */
 171                                 while (iswdigit(*fmt)) {
 172                                         ++fmt;
 173                                 }
 174                         }
 175                 }
 176
 177                 /* length modifier */
 178                 format_length_modifier_t fmt_mod;
 179                 switch (*fmt) {
 180                         case 'h':
 181                                 ++fmt;
 182                                 if (*fmt == 'h') {
 183                                         ++fmt;
 184                                         fmt_mod = FMT_MOD_hh;
 185                                 } else {
 186                                         fmt_mod = FMT_MOD_h;
 187                                 }
 188                                 break;
 189
 190                         case 'l':
 191                                 ++fmt;
 192                                 if (*fmt == 'l') {
 193                                         ++fmt;
 194                                         fmt_mod = FMT_MOD_ll;
 195                                 } else {
 196                                         fmt_mod = FMT_MOD_l;
 197                                 }
 198                                 break;
 199
 200                         case 'L': ++fmt; fmt_mod = FMT_MOD_L;    break;
 201                         case 'j': ++fmt; fmt_mod = FMT_MOD_j;    break;
 202                         case 't': ++fmt; fmt_mod = FMT_MOD_t;    break;
 203                         case 'z': ++fmt; fmt_mod = FMT_MOD_z;    break;
 204                         case 'q': ++fmt; fmt_mod = FMT_MOD_q;    break;
 205                         default:         fmt_mod = FMT_MOD_NONE; break;
 206                 }
 207
 208                 if (*fmt == '\0') {
 209                         warningf(pos, "dangling %% in format string");
 210                         break;
 211                 }
 212
 213                 const type_t   *expected_type;
 214                 format_flags_t  allowed_flags;
 215                 switch (*fmt) {
 216                         case 'd':
 217                         case 'i':
 218                                 switch (fmt_mod) {
 219                                         case FMT_MOD_NONE: expected_type = type_int;       break;
 220                                         case FMT_MOD_hh:   expected_type = type_int;       break; /* TODO promoted signed char */
 221                                         case FMT_MOD_h:    expected_type = type_int;       break; /* TODO promoted short */
 222                                         case FMT_MOD_l:    expected_type = type_long;      break;
 223                                         case FMT_MOD_ll:   expected_type = type_long_long; break;
 224                                         case FMT_MOD_j:    expected_type = type_intmax_t;  break;
 225                                         case FMT_MOD_z:    expected_type = type_ssize_t;   break;
 226                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t; break;
 227
 228                                         default:
 229                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 230                                                 goto next_arg;
 231                                 }
 232                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_ZERO;
 233                                 break;
 234
 235                         case 'o':
 236                         case 'X':
 237                         case 'x':
 238                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 239                                 goto eval_fmt_mod_unsigned;
 240                                 break;
 241
 242                         case 'u':
 243                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_ZERO;
 244 eval_fmt_mod_unsigned:
 245                                 switch (fmt_mod) {
 246                                         case FMT_MOD_NONE: expected_type = type_unsigned_int;       break;
 247                                         case FMT_MOD_hh:   expected_type = type_int;                break; /* TODO promoted unsigned char */
 248                                         case FMT_MOD_h:    expected_type = type_int;                break; /* TODO promoted unsigned short */
 249                                         case FMT_MOD_l:    expected_type = type_unsigned_long;      break;
 250                                         case FMT_MOD_ll:   expected_type = type_unsigned_long_long; break;
 251                                         case FMT_MOD_j:    expected_type = type_uintmax_t;          break;
 252                                         case FMT_MOD_z:    expected_type = type_size_t;             break;
 253                                         case FMT_MOD_t:    expected_type = type_uptrdiff_t;         break;
 254
 255                                         default:
 256                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 257                                                 goto next_arg;
 258                                 }
 259                                 break;
 260
 261                         case 'A':
 262                         case 'a':
 263                         case 'E':
 264                         case 'e':
 265                         case 'F':
 266                         case 'f':
 267                         case 'G':
 268                         case 'g':
 269                                 switch (fmt_mod) {
 270                                         case FMT_MOD_l:    /* l modifier is ignored */
 271                                         case FMT_MOD_NONE: expected_type = type_double;      break;
 272                                         case FMT_MOD_L:    expected_type = type_long_double; break;
 273
 274                                         default:
 275                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 276                                                 goto next_arg;
 277                                 }
 278                                 allowed_flags = FMT_FLAG_MINUS | FMT_FLAG_SPACE | FMT_FLAG_PLUS | FMT_FLAG_HASH | FMT_FLAG_ZERO;
 279                                 break;
 280
 281                         case 'C':
 282                                 if (fmt_mod != FMT_MOD_NONE) {
 283                                         warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 284                                         goto next_arg;
 285                                 }
 286                                 expected_type = type_wchar_t;
 287                                 allowed_flags = FMT_FLAG_NONE;
 288                                 break;
 289
 290                         case 'c':
 291                                 expected_type = type_int;
 292                                 switch (fmt_mod) {
 293                                         case FMT_MOD_NONE: expected_type = type_int;    break; /* TODO promoted char */
 294                                         case FMT_MOD_l:    expected_type = type_wint_t; break;
 295
 296                                         default:
 297                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 298                                                 goto next_arg;
 299                                 }
 300                                 allowed_flags = FMT_FLAG_NONE;
 301                                 break;
 302
 303                         case 'S':
 304                                 if (fmt_mod != FMT_MOD_NONE) {
 305                                         warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 306                                         goto next_arg;
 307                                 }
 308                                 expected_type = type_wchar_t_ptr;
 309                                 allowed_flags = FMT_FLAG_NONE;
 310                                 break;
 311
 312                         case 's':
 313                                 switch (fmt_mod) {
 314                                         case FMT_MOD_NONE: expected_type = type_string;      break;
 315                                         case FMT_MOD_l:    expected_type = type_wchar_t_ptr; break;
 316
 317                                         default:
 318                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 319                                                 goto next_arg;
 320                                 }
 321                                 allowed_flags = FMT_FLAG_NONE;
 322                                 break;
 323
 324                         case 'p':
 325                                 if (fmt_mod != FMT_MOD_NONE) {
 326                                         warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 327                                         goto next_arg;
 328                                 }
 329                                 expected_type = type_void_ptr;
 330                                 allowed_flags = FMT_FLAG_NONE;
 331                                 break;
 332
 333                         case 'n':
 334                                 switch (fmt_mod) {
 335                                         case FMT_MOD_NONE: expected_type = type_int_ptr;         break;
 336                                         case FMT_MOD_hh:   expected_type = type_signed_char_ptr; break;
 337                                         case FMT_MOD_h:    expected_type = type_short_ptr;       break;
 338                                         case FMT_MOD_l:    expected_type = type_long_ptr;        break;
 339                                         case FMT_MOD_ll:   expected_type = type_long_long_ptr;   break;
 340                                         case FMT_MOD_j:    expected_type = type_intmax_t_ptr;    break;
 341                                         case FMT_MOD_z:    expected_type = type_ssize_t_ptr;     break;
 342                                         case FMT_MOD_t:    expected_type = type_ptrdiff_t_ptr;   break;
 343
 344                                         default:
 345                                                 warn_invalid_length_modifier(pos, fmt_mod, *fmt);
 346                                                 goto next_arg;
 347                                 }
 348                                 allowed_flags = FMT_FLAG_NONE;
 349                                 break;
 350
 351                         default:
 352                                 warningf(pos, "encountered unknown conversion specifier '%%%C'", (wint_t)*fmt);
 353                                 goto next_arg;
 354                 }
 355
 356                 if ((fmt_flags & ~allowed_flags) != 0) {
 357                         /* TODO better warning message text */
 358                         warningf(pos, "invalid format flags in conversion specification");
 359                 }
 360
 361                 if (arg == NULL) {
 362                         warningf(pos, "too few arguments for format string");
 363                         return;
 364                 }
 365
 366                 type_t *const arg_type = arg->expression->base.datatype;
 367                 if (is_type_pointer(expected_type)) {
 368                         type_t *const arg_skip = skip_typeref(arg_type);
 369                         if (is_type_pointer(arg_skip)) {
 370                                 type_t *const exp_to = skip_typeref(expected_type->pointer.points_to);
 371                                 type_t *const arg_to = skip_typeref(arg_skip->pointer.points_to);
 372                                 if (arg_to == exp_to) {
 373                                         goto next_arg;
 374                                 }
 375                         }
 376                 } else {
 377                         if (get_unqualified_type(skip_typeref(arg_type)) == expected_type) {
 378                                 goto next_arg;
 379                         }
 380                 }
 381                 if (is_type_valid(arg_type)) {
 382                         warningf(pos,
 383                                 "argument type '%T' does not match conversion specifier '%%%s%c'\n",
 384                                 arg_type, get_length_modifier_name(fmt_mod), (char)*fmt);
 385                 }
 386
 387 next_arg:
 388                 arg = arg->next;
 389         }
 390         if (fmt + 1 != wstring->begin + wstring->size) {
 391                 warningf(pos, "format string contains NUL");
 392         }
 393         if (arg != NULL) {
 394                 warningf(pos, "too many arguments for format string");
 395         }
 396 }
 397
 398 void check_format(const call_expression_t *const call)
 399 {
 400         const expression_t *const func_expr = call->function;
 401         if (func_expr->kind != EXPR_REFERENCE)
 402                 return;
 403
 404         const char            *const name = func_expr->reference.symbol->string;
 405         const call_argument_t *      arg  = call->arguments;
 406         if (strcmp(name, "wprintf") == 0) { /* TODO gammlig */
 407                 check_format_arguments(arg, arg->next);
 408         } else if (strcmp(name, "swprintf") == 0) {
 409                 arg = arg->next->next; /* skip destination buffer and size */
 410                 check_format_arguments(arg, arg->next);
 411         }
 412 }