1 /* Check calls to formatted I/O functions (-Wformat). 2 Copyright (C) 1992-2022 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify it under 7 the terms of the GNU General Public License as published by the Free 8 Software Foundation; either version 3, or (at your option) any later 9 version. 10 11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING3. If not see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef GCC_C_FORMAT_H 21 #define GCC_C_FORMAT_H 22 23 /* The meaningfully distinct length modifiers for format checking recognized 24 by GCC. */ 25 enum format_lengths 26 { 27 FMT_LEN_none, 28 FMT_LEN_hh, 29 FMT_LEN_h, 30 FMT_LEN_l, 31 FMT_LEN_ll, 32 FMT_LEN_L, 33 FMT_LEN_z, 34 FMT_LEN_t, 35 FMT_LEN_j, 36 FMT_LEN_H, 37 FMT_LEN_D, 38 FMT_LEN_DD, 39 FMT_LEN_w, /* GCC's HOST_WIDE_INT. */ 40 FMT_LEN_MAX 41 }; 42 43 44 /* The standard versions in which various format features appeared. */ 45 enum format_std_version 46 { 47 STD_C89, 48 STD_C94, 49 STD_C9L, /* C99, but treat as C89 if -Wno-long-long. */ 50 STD_C99, 51 STD_C2X, 52 STD_EXT 53 }; 54 55 /* Flags that may apply to a particular kind of format checked by GCC. */ 56 enum 57 { 58 /* This format converts arguments of types determined by the 59 format string. */ 60 FMT_FLAG_ARG_CONVERT = 1, 61 /* The scanf allocation 'a' kludge applies to this format kind. */ 62 FMT_FLAG_SCANF_A_KLUDGE = 2, 63 /* A % during parsing a specifier is allowed to be a modified % rather 64 that indicating the format is broken and we are out-of-sync. */ 65 FMT_FLAG_FANCY_PERCENT_OK = 4, 66 /* With $ operand numbers, it is OK to reference the same argument more 67 than once. */ 68 FMT_FLAG_DOLLAR_MULTIPLE = 8, 69 /* This format type uses $ operand numbers (strfmon doesn't). */ 70 FMT_FLAG_USE_DOLLAR = 16, 71 /* Zero width is bad in this type of format (scanf). */ 72 FMT_FLAG_ZERO_WIDTH_BAD = 32, 73 /* Empty precision specification is OK in this type of format (printf). */ 74 FMT_FLAG_EMPTY_PREC_OK = 64, 75 /* Gaps are allowed in the arguments with $ operand numbers if all 76 arguments are pointers (scanf). */ 77 FMT_FLAG_DOLLAR_GAP_POINTER_OK = 128, 78 /* The format arg is an opaque object that will be parsed by an external 79 facility. */ 80 FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL = 256, 81 /* Not included here: details of whether width or precision may occur 82 (controlled by width_char and precision_char); details of whether 83 '*' can be used for these (width_type and precision_type); details 84 of whether length modifiers can occur (length_char_specs). */ 85 FMT_FLAG_M_OK = 512 86 /* %m is only allowed in syslog */ 87 }; 88 89 /* Structure describing a length modifier supported in format checking, and 90 possibly a doubled version such as "hh". */ 91 struct format_length_info 92 { 93 /* Name of the single-character length modifier. If prefixed by 94 a zero character, it describes a multi character length 95 modifier, like I64, I32, etc. */ 96 const char *name; 97 /* Index into a format_char_info.types array. */ 98 enum format_lengths index; 99 /* Standard version this length appears in. */ 100 enum format_std_version std; 101 /* Same, if the modifier can be repeated, or NULL if it can't. */ 102 const char *double_name; 103 enum format_lengths double_index; 104 enum format_std_version double_std; 105 106 /* If this flag is set, just scalar width identity is checked, and 107 not the type identity itself. */ 108 int scalar_identity_flag; 109 }; 110 111 112 /* Structure describing the combination of a conversion specifier 113 (or a set of specifiers which act identically) and a length modifier. */ 114 struct format_type_detail 115 { 116 /* The standard version this combination of length and type appeared in. 117 This is only relevant if greater than those for length and type 118 individually; otherwise it is ignored. */ 119 enum format_std_version std; 120 /* The name to use for the type, if different from that generated internally 121 (e.g., "signed size_t"). */ 122 const char *name; 123 /* The type itself. */ 124 tree *type; 125 }; 126 127 128 /* Macros to fill out tables of these. */ 129 #define NOARGUMENTS { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN } 130 #define BADLEN { STD_C89, NULL, NULL } 131 #define NOLENGTHS { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN } 132 133 134 /* Structure describing a format conversion specifier (or a set of specifiers 135 which act identically), and the length modifiers used with it. */ 136 struct format_char_info 137 { 138 const char *format_chars; 139 int pointer_count; 140 enum format_std_version std; 141 /* Types accepted for each length modifier. */ 142 format_type_detail types[FMT_LEN_MAX]; 143 /* List of other modifier characters allowed with these specifiers. 144 This lists flags, and additionally "w" for width, "p" for precision 145 (right precision, for strfmon), "#" for left precision (strfmon), 146 "a" for scanf "a" allocation extension (not applicable in C99 mode), 147 "*" for scanf suppression, and "E" and "O" for those strftime 148 modifiers. */ 149 const char *flag_chars; 150 /* List of additional flags describing these conversion specifiers. 151 "c" for generic character pointers being allowed, "2" for strftime 152 two digit year formats, "3" for strftime formats giving two digit 153 years in some locales, "4" for "2" which becomes "3" with an "E" modifier, 154 "o" if use of strftime "O" is a GNU extension beyond C99, 155 "p" if use of strftime "O" is a C2x feature, 156 "W" if the argument is a pointer which is dereferenced and written into, 157 "R" if the argument is a pointer which is dereferenced and read from, 158 "i" for printf integer formats where the '0' flag is ignored with 159 precision, and "[" for the starting character of a scanf scanset, 160 "<" if the specifier introduces a quoted sequence (such as "%<"), 161 ">" if the specifier terminates a quoted sequence (such as "%>"), 162 "[" if the specifier introduces a color sequence (such as "%r"), 163 "]" if the specifier terminates a color sequence (such as "%R"), 164 "'" (single quote) if the specifier is expected to be quoted when 165 it appears outside a quoted sequence and unquoted otherwise (such 166 as the GCC internal printf format directive "%T"), and 167 "\"" (double quote) if the specifier is not expected to appear in 168 a quoted sequence (such as the GCC internal format directive "%K". */ 169 const char *flags2; 170 /* If this format conversion character consumes more than one argument, 171 CHAIN points to information about the next argument. For later 172 arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags 173 in FLAGS2 are used. */ 174 const struct format_char_info *chain; 175 }; 176 177 178 /* Structure describing a flag accepted by some kind of format. */ 179 struct format_flag_spec 180 { 181 /* The flag character in question (0 for end of array). */ 182 int flag_char; 183 /* Zero if this entry describes the flag character in general, or a 184 nonzero character that may be found in flags2 if it describes the 185 flag when used with certain formats only. If the latter, only 186 the first such entry found that applies to the current conversion 187 specifier is used; the values of 'name' and 'long_name' it supplies 188 will be used, if non-NULL and the standard version is higher than 189 the unpredicated one, for any pedantic warning. For example, 'o' 190 for strftime formats (meaning 'O' is an extension over C99). */ 191 int predicate; 192 /* Nonzero if the next character after this flag in the format should 193 be skipped ('=' in strfmon), zero otherwise. */ 194 int skip_next_char; 195 /* True if the flag introduces quoting (as in GCC's %qE). */ 196 bool quoting; 197 /* The name to use for this flag in diagnostic messages. For example, 198 N_("'0' flag"), N_("field width"). */ 199 const char *name; 200 /* Long name for this flag in diagnostic messages; currently only used for 201 "ISO C does not support ...". For example, N_("the 'I' printf flag"). */ 202 const char *long_name; 203 /* The standard version in which it appeared. */ 204 enum format_std_version std; 205 }; 206 207 208 /* Structure describing a combination of flags that is bad for some kind 209 of format. */ 210 struct format_flag_pair 211 { 212 /* The first flag character in question (0 for end of array). */ 213 int flag_char1; 214 /* The second flag character. */ 215 int flag_char2; 216 /* Nonzero if the message should say that the first flag is ignored with 217 the second, zero if the combination should simply be objected to. */ 218 int ignored; 219 /* Zero if this entry applies whenever this flag combination occurs, 220 a nonzero character from flags2 if it only applies in some 221 circumstances (e.g. 'i' for printf formats ignoring 0 with precision). */ 222 int predicate; 223 }; 224 225 226 /* Structure describing a particular kind of format processed by GCC. */ 227 struct format_kind_info 228 { 229 /* The name of this kind of format, for use in diagnostics. Also 230 the name of the attribute (without preceding and following __). */ 231 const char *name; 232 /* Specifications of the length modifiers accepted; possibly NULL. */ 233 const format_length_info *length_char_specs; 234 /* Details of the conversion specification characters accepted. */ 235 const format_char_info *conversion_specs; 236 /* String listing the flag characters that are accepted. */ 237 const char *flag_chars; 238 /* String listing modifier characters (strftime) accepted. May be NULL. */ 239 const char *modifier_chars; 240 /* Details of the flag characters, including pseudo-flags. */ 241 const format_flag_spec *flag_specs; 242 /* Details of bad combinations of flags. */ 243 const format_flag_pair *bad_flag_pairs; 244 /* Flags applicable to this kind of format. */ 245 int flags; 246 /* Flag character to treat a width as, or 0 if width not used. */ 247 int width_char; 248 /* Flag character to treat a left precision (strfmon) as, 249 or 0 if left precision not used. */ 250 int left_precision_char; 251 /* Flag character to treat a precision (for strfmon, right precision) as, 252 or 0 if precision not used. */ 253 int precision_char; 254 /* If a flag character has the effect of suppressing the conversion of 255 an argument ('*' in scanf), that flag character, otherwise 0. */ 256 int suppression_char; 257 /* Flag character to treat a length modifier as (ignored if length 258 modifiers not used). Need not be placed in flag_chars for conversion 259 specifiers, but is used to check for bad combinations such as length 260 modifier with assignment suppression in scanf. */ 261 int length_code_char; 262 /* Assignment-allocation flag character ('m' in scanf), otherwise 0. */ 263 int alloc_char; 264 /* Pointer to type of argument expected if '*' is used for a width, 265 or NULL if '*' not used for widths. */ 266 tree *width_type; 267 /* Pointer to type of argument expected if '*' is used for a precision, 268 or NULL if '*' not used for precisions. */ 269 tree *precision_type; 270 /* A format type that is a subset of our format */ 271 int parent_format_type; 272 }; 273 274 #define T_I &integer_type_node 275 #define T89_I { STD_C89, NULL, T_I } 276 #define T_L &long_integer_type_node 277 #define T89_L { STD_C89, NULL, T_L } 278 #define T_LL &long_long_integer_type_node 279 #define T9L_LL { STD_C9L, NULL, T_LL } 280 #define TEX_LL { STD_EXT, NULL, T_LL } 281 #define T_S &short_integer_type_node 282 #define T89_S { STD_C89, NULL, T_S } 283 #define T_UI &unsigned_type_node 284 #define T89_UI { STD_C89, NULL, T_UI } 285 #define T2X_UI { STD_C2X, NULL, T_UI } 286 #define T_UL &long_unsigned_type_node 287 #define T89_UL { STD_C89, NULL, T_UL } 288 #define T2X_UL { STD_C2X, NULL, T_UL } 289 #define T_ULL &long_long_unsigned_type_node 290 #define T9L_ULL { STD_C9L, NULL, T_ULL } 291 #define T2X_ULL { STD_C2X, NULL, T_ULL } 292 #define TEX_ULL { STD_EXT, NULL, T_ULL } 293 #define T_US &short_unsigned_type_node 294 #define T89_US { STD_C89, NULL, T_US } 295 #define T2X_US { STD_C2X, NULL, T_US } 296 #define T_F &float_type_node 297 #define T89_F { STD_C89, NULL, T_F } 298 #define T99_F { STD_C99, NULL, T_F } 299 #define T_D &double_type_node 300 #define T89_D { STD_C89, NULL, T_D } 301 #define T99_D { STD_C99, NULL, T_D } 302 #define T_LD &long_double_type_node 303 #define T89_LD { STD_C89, NULL, T_LD } 304 #define T99_LD { STD_C99, NULL, T_LD } 305 #define T_C &char_type_node 306 #define T89_C { STD_C89, NULL, T_C } 307 #define T_SC &signed_char_type_node 308 #define T99_SC { STD_C99, NULL, T_SC } 309 #define T_UC &unsigned_char_type_node 310 #define T99_UC { STD_C99, NULL, T_UC } 311 #define T2X_UC { STD_C2X, NULL, T_UC } 312 #define T_V &void_type_node 313 #define T89_G { STD_C89, NULL, &local_gimple_ptr_node } 314 #define T_CGRAPH_NODE { STD_C89, NULL, &local_cgraph_node_ptr_node } 315 #define T_EVENT_PTR { STD_C89, NULL, &local_event_ptr_node } 316 #define T89_T { STD_C89, NULL, &local_tree_type_node } 317 #define T89_V { STD_C89, NULL, T_V } 318 #define T_W &wchar_type_node 319 #define T94_W { STD_C94, "wchar_t", T_W } 320 #define TEX_W { STD_EXT, "wchar_t", T_W } 321 #define T_WI &wint_type_node 322 #define T94_WI { STD_C94, "wint_t", T_WI } 323 #define TEX_WI { STD_EXT, "wint_t", T_WI } 324 #define T_ST &size_type_node 325 #define T99_ST { STD_C99, "size_t", T_ST } 326 #define T2X_ST { STD_C2X, "size_t", T_ST } 327 #define T_SST &signed_size_type_node 328 #define T99_SST { STD_C99, "signed size_t", T_SST } 329 #define T_PD &ptrdiff_type_node 330 #define T99_PD { STD_C99, "ptrdiff_t", T_PD } 331 #define T_UPD &unsigned_ptrdiff_type_node 332 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD } 333 #define T2X_UPD { STD_C2X, "unsigned ptrdiff_t", T_UPD } 334 #define T_IM &intmax_type_node 335 #define T99_IM { STD_C99, "intmax_t", T_IM } 336 #define T_UIM &uintmax_type_node 337 #define T99_UIM { STD_C99, "uintmax_t", T_UIM } 338 #define T2X_UIM { STD_C2X, "uintmax_t", T_UIM } 339 #define T_D32 &dfloat32_type_node 340 #define T2X_D32 { STD_C2X, "_Decimal32", T_D32 } 341 #define T_D64 &dfloat64_type_node 342 #define T2X_D64 { STD_C2X, "_Decimal64", T_D64 } 343 #define T_D128 &dfloat128_type_node 344 #define T2X_D128 { STD_C2X, "_Decimal128", T_D128 } 345 346 /* Structure describing how format attributes such as "printf" are 347 interpreted as "gnu_printf" or "ms_printf" on a particular system. 348 TARGET_OVERRIDES_FORMAT_ATTRIBUTES is used to specify target-specific 349 defaults. */ 350 struct target_ovr_attr 351 { 352 /* The name of the to be copied format attribute. */ 353 const char *named_attr_src; 354 /* The name of the to be overridden format attribute. */ 355 const char *named_attr_dst; 356 }; 357 358 #endif /* GCC_C_FORMAT_H */ 359