1 /* Check calls to formatted I/O functions (-Wformat). 2 Copyright (C) 1992-2019 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_MAX 40 }; 41 42 43 /* The standard versions in which various format features appeared. */ 44 enum format_std_version 45 { 46 STD_C89, 47 STD_C94, 48 STD_C9L, /* C99, but treat as C89 if -Wno-long-long. */ 49 STD_C99, 50 STD_EXT 51 }; 52 53 /* Flags that may apply to a particular kind of format checked by GCC. */ 54 enum 55 { 56 /* This format converts arguments of types determined by the 57 format string. */ 58 FMT_FLAG_ARG_CONVERT = 1, 59 /* The scanf allocation 'a' kludge applies to this format kind. */ 60 FMT_FLAG_SCANF_A_KLUDGE = 2, 61 /* A % during parsing a specifier is allowed to be a modified % rather 62 that indicating the format is broken and we are out-of-sync. */ 63 FMT_FLAG_FANCY_PERCENT_OK = 4, 64 /* With $ operand numbers, it is OK to reference the same argument more 65 than once. */ 66 FMT_FLAG_DOLLAR_MULTIPLE = 8, 67 /* This format type uses $ operand numbers (strfmon doesn't). */ 68 FMT_FLAG_USE_DOLLAR = 16, 69 /* Zero width is bad in this type of format (scanf). */ 70 FMT_FLAG_ZERO_WIDTH_BAD = 32, 71 /* Empty precision specification is OK in this type of format (printf). */ 72 FMT_FLAG_EMPTY_PREC_OK = 64, 73 /* Gaps are allowed in the arguments with $ operand numbers if all 74 arguments are pointers (scanf). */ 75 FMT_FLAG_DOLLAR_GAP_POINTER_OK = 128, 76 /* The format arg is an opaque object that will be parsed by an external 77 facility. */ 78 FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL = 256, 79 /* Not included here: details of whether width or precision may occur 80 (controlled by width_char and precision_char); details of whether 81 '*' can be used for these (width_type and precision_type); details 82 of whether length modifiers can occur (length_char_specs). */ 83 FMT_FLAG_M_OK = 512 84 /* %m is only allowed in syslog */ 85 }; 86 87 /* Structure describing a length modifier supported in format checking, and 88 possibly a doubled version such as "hh". */ 89 struct format_length_info 90 { 91 /* Name of the single-character length modifier. If prefixed by 92 a zero character, it describes a multi character length 93 modifier, like I64, I32, etc. */ 94 const char *name; 95 /* Index into a format_char_info.types array. */ 96 enum format_lengths index; 97 /* Standard version this length appears in. */ 98 enum format_std_version std; 99 /* Same, if the modifier can be repeated, or NULL if it can't. */ 100 const char *double_name; 101 enum format_lengths double_index; 102 enum format_std_version double_std; 103 104 /* If this flag is set, just scalar width identity is checked, and 105 not the type identity itself. */ 106 int scalar_identity_flag; 107 }; 108 109 110 /* Structure describing the combination of a conversion specifier 111 (or a set of specifiers which act identically) and a length modifier. */ 112 struct format_type_detail 113 { 114 /* The standard version this combination of length and type appeared in. 115 This is only relevant if greater than those for length and type 116 individually; otherwise it is ignored. */ 117 enum format_std_version std; 118 /* The name to use for the type, if different from that generated internally 119 (e.g., "signed size_t"). */ 120 const char *name; 121 /* The type itself. */ 122 tree *type; 123 }; 124 125 126 /* Macros to fill out tables of these. */ 127 #define NOARGUMENTS { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN } 128 #define BADLEN { STD_C89, NULL, NULL } 129 #define NOLENGTHS { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN } 130 131 132 /* Structure describing a format conversion specifier (or a set of specifiers 133 which act identically), and the length modifiers used with it. */ 134 struct format_char_info 135 { 136 const char *format_chars; 137 int pointer_count; 138 enum format_std_version std; 139 /* Types accepted for each length modifier. */ 140 format_type_detail types[FMT_LEN_MAX]; 141 /* List of other modifier characters allowed with these specifiers. 142 This lists flags, and additionally "w" for width, "p" for precision 143 (right precision, for strfmon), "#" for left precision (strfmon), 144 "a" for scanf "a" allocation extension (not applicable in C99 mode), 145 "*" for scanf suppression, and "E" and "O" for those strftime 146 modifiers. */ 147 const char *flag_chars; 148 /* List of additional flags describing these conversion specifiers. 149 "c" for generic character pointers being allowed, "2" for strftime 150 two digit year formats, "3" for strftime formats giving two digit 151 years in some locales, "4" for "2" which becomes "3" with an "E" modifier, 152 "o" if use of strftime "O" is a GNU extension beyond C99, 153 "W" if the argument is a pointer which is dereferenced and written into, 154 "R" if the argument is a pointer which is dereferenced and read from, 155 "i" for printf integer formats where the '0' flag is ignored with 156 precision, and "[" for the starting character of a scanf scanset, 157 "<" if the specifier introduces a quoted sequence (such as "%<"), 158 ">" if the specifier terminates a quoted sequence (such as "%>"), 159 "[" if the specifier introduces a color sequence (such as "%r"), 160 "]" if the specifier terminates a color sequence (such as "%R"), 161 "'" (single quote) if the specifier is expected to be quoted when 162 it appears outside a quoted sequence and unquoted otherwise (such 163 as the GCC internal printf format directive "%T"), and 164 "\"" (double quote) if the specifier is not expected to appear in 165 a quoted sequence (such as the GCC internal format directive "%K". */ 166 const char *flags2; 167 /* If this format conversion character consumes more than one argument, 168 CHAIN points to information about the next argument. For later 169 arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags 170 in FLAGS2 are used. */ 171 const struct format_char_info *chain; 172 }; 173 174 175 /* Structure describing a flag accepted by some kind of format. */ 176 struct format_flag_spec 177 { 178 /* The flag character in question (0 for end of array). */ 179 int flag_char; 180 /* Zero if this entry describes the flag character in general, or a 181 nonzero character that may be found in flags2 if it describes the 182 flag when used with certain formats only. If the latter, only 183 the first such entry found that applies to the current conversion 184 specifier is used; the values of 'name' and 'long_name' it supplies 185 will be used, if non-NULL and the standard version is higher than 186 the unpredicated one, for any pedantic warning. For example, 'o' 187 for strftime formats (meaning 'O' is an extension over C99). */ 188 int predicate; 189 /* Nonzero if the next character after this flag in the format should 190 be skipped ('=' in strfmon), zero otherwise. */ 191 int skip_next_char; 192 /* True if the flag introduces quoting (as in GCC's %qE). */ 193 bool quoting; 194 /* The name to use for this flag in diagnostic messages. For example, 195 N_("'0' flag"), N_("field width"). */ 196 const char *name; 197 /* Long name for this flag in diagnostic messages; currently only used for 198 "ISO C does not support ...". For example, N_("the 'I' printf flag"). */ 199 const char *long_name; 200 /* The standard version in which it appeared. */ 201 enum format_std_version std; 202 }; 203 204 205 /* Structure describing a combination of flags that is bad for some kind 206 of format. */ 207 struct format_flag_pair 208 { 209 /* The first flag character in question (0 for end of array). */ 210 int flag_char1; 211 /* The second flag character. */ 212 int flag_char2; 213 /* Nonzero if the message should say that the first flag is ignored with 214 the second, zero if the combination should simply be objected to. */ 215 int ignored; 216 /* Zero if this entry applies whenever this flag combination occurs, 217 a nonzero character from flags2 if it only applies in some 218 circumstances (e.g. 'i' for printf formats ignoring 0 with precision). */ 219 int predicate; 220 }; 221 222 223 /* Structure describing a particular kind of format processed by GCC. */ 224 struct format_kind_info 225 { 226 /* The name of this kind of format, for use in diagnostics. Also 227 the name of the attribute (without preceding and following __). */ 228 const char *name; 229 /* Specifications of the length modifiers accepted; possibly NULL. */ 230 const format_length_info *length_char_specs; 231 /* Details of the conversion specification characters accepted. */ 232 const format_char_info *conversion_specs; 233 /* String listing the flag characters that are accepted. */ 234 const char *flag_chars; 235 /* String listing modifier characters (strftime) accepted. May be NULL. */ 236 const char *modifier_chars; 237 /* Details of the flag characters, including pseudo-flags. */ 238 const format_flag_spec *flag_specs; 239 /* Details of bad combinations of flags. */ 240 const format_flag_pair *bad_flag_pairs; 241 /* Flags applicable to this kind of format. */ 242 int flags; 243 /* Flag character to treat a width as, or 0 if width not used. */ 244 int width_char; 245 /* Flag character to treat a left precision (strfmon) as, 246 or 0 if left precision not used. */ 247 int left_precision_char; 248 /* Flag character to treat a precision (for strfmon, right precision) as, 249 or 0 if precision not used. */ 250 int precision_char; 251 /* If a flag character has the effect of suppressing the conversion of 252 an argument ('*' in scanf), that flag character, otherwise 0. */ 253 int suppression_char; 254 /* Flag character to treat a length modifier as (ignored if length 255 modifiers not used). Need not be placed in flag_chars for conversion 256 specifiers, but is used to check for bad combinations such as length 257 modifier with assignment suppression in scanf. */ 258 int length_code_char; 259 /* Assignment-allocation flag character ('m' in scanf), otherwise 0. */ 260 int alloc_char; 261 /* Pointer to type of argument expected if '*' is used for a width, 262 or NULL if '*' not used for widths. */ 263 tree *width_type; 264 /* Pointer to type of argument expected if '*' is used for a precision, 265 or NULL if '*' not used for precisions. */ 266 tree *precision_type; 267 /* A format type that is a subset of our format */ 268 int parent_format_type; 269 }; 270 271 #define T_I &integer_type_node 272 #define T89_I { STD_C89, NULL, T_I } 273 #define T_L &long_integer_type_node 274 #define T89_L { STD_C89, NULL, T_L } 275 #define T_LL &long_long_integer_type_node 276 #define T9L_LL { STD_C9L, NULL, T_LL } 277 #define TEX_LL { STD_EXT, NULL, T_LL } 278 #define T_S &short_integer_type_node 279 #define T89_S { STD_C89, NULL, T_S } 280 #define T_UI &unsigned_type_node 281 #define T89_UI { STD_C89, NULL, T_UI } 282 #define T_UL &long_unsigned_type_node 283 #define T89_UL { STD_C89, NULL, T_UL } 284 #define T_ULL &long_long_unsigned_type_node 285 #define T9L_ULL { STD_C9L, NULL, T_ULL } 286 #define TEX_ULL { STD_EXT, NULL, T_ULL } 287 #define T_US &short_unsigned_type_node 288 #define T89_US { STD_C89, NULL, T_US } 289 #define T_F &float_type_node 290 #define T89_F { STD_C89, NULL, T_F } 291 #define T99_F { STD_C99, NULL, T_F } 292 #define T_D &double_type_node 293 #define T89_D { STD_C89, NULL, T_D } 294 #define T99_D { STD_C99, NULL, T_D } 295 #define T_LD &long_double_type_node 296 #define T89_LD { STD_C89, NULL, T_LD } 297 #define T99_LD { STD_C99, NULL, T_LD } 298 #define T_C &char_type_node 299 #define T89_C { STD_C89, NULL, T_C } 300 #define T_SC &signed_char_type_node 301 #define T99_SC { STD_C99, NULL, T_SC } 302 #define T_UC &unsigned_char_type_node 303 #define T99_UC { STD_C99, NULL, T_UC } 304 #define T_V &void_type_node 305 #define T89_G { STD_C89, NULL, &local_gimple_ptr_node } 306 #define T_CGRAPH_NODE { STD_C89, NULL, &local_cgraph_node_ptr_node } 307 #define T89_T { STD_C89, NULL, &local_tree_type_node } 308 #define T89_V { STD_C89, NULL, T_V } 309 #define T_W &wchar_type_node 310 #define T94_W { STD_C94, "wchar_t", T_W } 311 #define TEX_W { STD_EXT, "wchar_t", T_W } 312 #define T_WI &wint_type_node 313 #define T94_WI { STD_C94, "wint_t", T_WI } 314 #define TEX_WI { STD_EXT, "wint_t", T_WI } 315 #define T_ST &size_type_node 316 #define T99_ST { STD_C99, "size_t", T_ST } 317 #define T_SST &signed_size_type_node 318 #define T99_SST { STD_C99, "signed size_t", T_SST } 319 #define T_PD &ptrdiff_type_node 320 #define T99_PD { STD_C99, "ptrdiff_t", T_PD } 321 #define T_UPD &unsigned_ptrdiff_type_node 322 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD } 323 #define T_IM &intmax_type_node 324 #define T99_IM { STD_C99, "intmax_t", T_IM } 325 #define T_UIM &uintmax_type_node 326 #define T99_UIM { STD_C99, "uintmax_t", T_UIM } 327 #define T_D32 &dfloat32_type_node 328 #define TEX_D32 { STD_EXT, "_Decimal32", T_D32 } 329 #define T_D64 &dfloat64_type_node 330 #define TEX_D64 { STD_EXT, "_Decimal64", T_D64 } 331 #define T_D128 &dfloat128_type_node 332 #define TEX_D128 { STD_EXT, "_Decimal128", T_D128 } 333 334 /* Structure describing how format attributes such as "printf" are 335 interpreted as "gnu_printf" or "ms_printf" on a particular system. 336 TARGET_OVERRIDES_FORMAT_ATTRIBUTES is used to specify target-specific 337 defaults. */ 338 struct target_ovr_attr 339 { 340 /* The name of the to be copied format attribute. */ 341 const char *named_attr_src; 342 /* The name of the to be overridden format attribute. */ 343 const char *named_attr_dst; 344 }; 345 346 #endif /* GCC_C_FORMAT_H */ 347