gcc/c-format.h

   1 /* Check calls to formatted I/O functions (-Wformat).
   2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_C_FORMAT_H
  22 #define GCC_C_FORMAT_H
  23
  24 /* The meaningfully distinct length modifiers for format checking recognized
  25    by GCC.  */
  26 enum format_lengths
  27 {
  28   FMT_LEN_none,
  29   FMT_LEN_hh,
  30   FMT_LEN_h,
  31   FMT_LEN_l,
  32   FMT_LEN_ll,
  33   FMT_LEN_L,
  34   FMT_LEN_z,
  35   FMT_LEN_t,
  36   FMT_LEN_j,
  37   FMT_LEN_H,
  38   FMT_LEN_D,
  39   FMT_LEN_DD,
  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_EXT
  52 };
  53
  54 /* Flags that may apply to a particular kind of format checked by GCC.  */
  55 enum
  56 {
  57   /* This format converts arguments of types determined by the
  58      format string.  */
  59   FMT_FLAG_ARG_CONVERT = 1,
  60   /* The scanf allocation 'a' kludge applies to this format kind.  */
  61   FMT_FLAG_SCANF_A_KLUDGE = 2,
  62   /* A % during parsing a specifier is allowed to be a modified % rather
  63      that indicating the format is broken and we are out-of-sync.  */
  64   FMT_FLAG_FANCY_PERCENT_OK = 4,
  65   /* With $ operand numbers, it is OK to reference the same argument more
  66      than once.  */
  67   FMT_FLAG_DOLLAR_MULTIPLE = 8,
  68   /* This format type uses $ operand numbers (strfmon doesn't).  */
  69   FMT_FLAG_USE_DOLLAR = 16,
  70   /* Zero width is bad in this type of format (scanf).  */
  71   FMT_FLAG_ZERO_WIDTH_BAD = 32,
  72   /* Empty precision specification is OK in this type of format (printf).  */
  73   FMT_FLAG_EMPTY_PREC_OK = 64,
  74   /* Gaps are allowed in the arguments with $ operand numbers if all
  75      arguments are pointers (scanf).  */
  76   FMT_FLAG_DOLLAR_GAP_POINTER_OK = 128
  77   /* Not included here: details of whether width or precision may occur
  78      (controlled by width_char and precision_char); details of whether
  79      '*' can be used for these (width_type and precision_type); details
  80      of whether length modifiers can occur (length_char_specs).  */
  81 };
  82
  83
  84 /* Structure describing a length modifier supported in format checking, and
  85    possibly a doubled version such as "hh".  */
  86 typedef struct
  87 {
  88   /* Name of the single-character length modifier.  */
  89   const char *name;
  90   /* Index into a format_char_info.types array.  */
  91   enum format_lengths index;
  92   /* Standard version this length appears in.  */
  93   enum format_std_version std;
  94   /* Same, if the modifier can be repeated, or NULL if it can't.  */
  95   const char *double_name;
  96   enum format_lengths double_index;
  97   enum format_std_version double_std;
  98 } format_length_info;
  99
 100
 101 /* Structure describing the combination of a conversion specifier
 102    (or a set of specifiers which act identically) and a length modifier.  */
 103 typedef struct
 104 {
 105   /* The standard version this combination of length and type appeared in.
 106      This is only relevant if greater than those for length and type
 107      individually; otherwise it is ignored.  */
 108   enum format_std_version std;
 109   /* The name to use for the type, if different from that generated internally
 110      (e.g., "signed size_t").  */
 111   const char *name;
 112   /* The type itself.  */
 113   tree *type;
 114 } format_type_detail;
 115
 116
 117 /* Macros to fill out tables of these.  */
 118 #define NOARGUMENTS     { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 119 #define BADLEN  { 0, NULL, NULL }
 120 #define NOLENGTHS       { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 121
 122
 123 /* Structure describing a format conversion specifier (or a set of specifiers
 124    which act identically), and the length modifiers used with it.  */
 125 typedef struct format_char_info
 126 {
 127   const char *format_chars;
 128   int pointer_count;
 129   enum format_std_version std;
 130   /* Types accepted for each length modifier.  */
 131   format_type_detail types[FMT_LEN_MAX];
 132   /* List of other modifier characters allowed with these specifiers.
 133      This lists flags, and additionally "w" for width, "p" for precision
 134      (right precision, for strfmon), "#" for left precision (strfmon),
 135      "a" for scanf "a" allocation extension (not applicable in C99 mode),
 136      "*" for scanf suppression, and "E" and "O" for those strftime
 137      modifiers.  */
 138   const char *flag_chars;
 139   /* List of additional flags describing these conversion specifiers.
 140      "c" for generic character pointers being allowed, "2" for strftime
 141      two digit year formats, "3" for strftime formats giving two digit
 142      years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
 143      "o" if use of strftime "O" is a GNU extension beyond C99,
 144      "W" if the argument is a pointer which is dereferenced and written into,
 145      "R" if the argument is a pointer which is dereferenced and read from,
 146      "i" for printf integer formats where the '0' flag is ignored with
 147      precision, and "[" for the starting character of a scanf scanset.  */
 148   const char *flags2;
 149   /* If this format conversion character consumes more than one argument,
 150      CHAIN points to information about the next argument.  For later
 151      arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags
 152      in FLAGS2 are used.  */
 153   const struct format_char_info *chain;
 154 } format_char_info;
 155
 156
 157 /* Structure describing a flag accepted by some kind of format.  */
 158 typedef struct
 159 {
 160   /* The flag character in question (0 for end of array).  */
 161   int flag_char;
 162   /* Zero if this entry describes the flag character in general, or a
 163      nonzero character that may be found in flags2 if it describes the
 164      flag when used with certain formats only.  If the latter, only
 165      the first such entry found that applies to the current conversion
 166      specifier is used; the values of 'name' and 'long_name' it supplies
 167      will be used, if non-NULL and the standard version is higher than
 168      the unpredicated one, for any pedantic warning.  For example, 'o'
 169      for strftime formats (meaning 'O' is an extension over C99).  */
 170   int predicate;
 171   /* Nonzero if the next character after this flag in the format should
 172      be skipped ('=' in strfmon), zero otherwise.  */
 173   int skip_next_char;
 174   /* The name to use for this flag in diagnostic messages.  For example,
 175      N_("'0' flag"), N_("field width").  */
 176   const char *name;
 177   /* Long name for this flag in diagnostic messages; currently only used for
 178      "ISO C does not support ...".  For example, N_("the 'I' printf flag").  */
 179   const char *long_name;
 180   /* The standard version in which it appeared.  */
 181   enum format_std_version std;
 182 } format_flag_spec;
 183
 184
 185 /* Structure describing a combination of flags that is bad for some kind
 186    of format.  */
 187 typedef struct
 188 {
 189   /* The first flag character in question (0 for end of array).  */
 190   int flag_char1;
 191   /* The second flag character.  */
 192   int flag_char2;
 193   /* Nonzero if the message should say that the first flag is ignored with
 194      the second, zero if the combination should simply be objected to.  */
 195   int ignored;
 196   /* Zero if this entry applies whenever this flag combination occurs,
 197      a nonzero character from flags2 if it only applies in some
 198      circumstances (e.g. 'i' for printf formats ignoring 0 with precision).  */
 199   int predicate;
 200 } format_flag_pair;
 201
 202
 203 /* Structure describing a particular kind of format processed by GCC.  */
 204 typedef struct
 205 {
 206   /* The name of this kind of format, for use in diagnostics.  Also
 207      the name of the attribute (without preceding and following __).  */
 208   const char *name;
 209   /* Specifications of the length modifiers accepted; possibly NULL.  */
 210   const format_length_info *length_char_specs;
 211   /* Details of the conversion specification characters accepted.  */
 212   const format_char_info *conversion_specs;
 213   /* String listing the flag characters that are accepted.  */
 214   const char *flag_chars;
 215   /* String listing modifier characters (strftime) accepted.  May be NULL.  */
 216   const char *modifier_chars;
 217   /* Details of the flag characters, including pseudo-flags.  */
 218   const format_flag_spec *flag_specs;
 219   /* Details of bad combinations of flags.  */
 220   const format_flag_pair *bad_flag_pairs;
 221   /* Flags applicable to this kind of format.  */
 222   int flags;
 223   /* Flag character to treat a width as, or 0 if width not used.  */
 224   int width_char;
 225   /* Flag character to treat a left precision (strfmon) as,
 226      or 0 if left precision not used.  */
 227   int left_precision_char;
 228   /* Flag character to treat a precision (for strfmon, right precision) as,
 229      or 0 if precision not used.  */
 230   int precision_char;
 231   /* If a flag character has the effect of suppressing the conversion of
 232      an argument ('*' in scanf), that flag character, otherwise 0.  */
 233   int suppression_char;
 234   /* Flag character to treat a length modifier as (ignored if length
 235      modifiers not used).  Need not be placed in flag_chars for conversion
 236      specifiers, but is used to check for bad combinations such as length
 237      modifier with assignment suppression in scanf.  */
 238   int length_code_char;
 239   /* Assignment-allocation flag character ('m' in scanf), otherwise 0.  */
 240   int alloc_char;
 241   /* Pointer to type of argument expected if '*' is used for a width,
 242      or NULL if '*' not used for widths.  */
 243   tree *width_type;
 244   /* Pointer to type of argument expected if '*' is used for a precision,
 245      or NULL if '*' not used for precisions.  */
 246   tree *precision_type;
 247 } format_kind_info;
 248
 249 #define T_I     &integer_type_node
 250 #define T89_I   { STD_C89, NULL, T_I }
 251 #define T_L     &long_integer_type_node
 252 #define T89_L   { STD_C89, NULL, T_L }
 253 #define T_LL    &long_long_integer_type_node
 254 #define T9L_LL  { STD_C9L, NULL, T_LL }
 255 #define TEX_LL  { STD_EXT, NULL, T_LL }
 256 #define T_S     &short_integer_type_node
 257 #define T89_S   { STD_C89, NULL, T_S }
 258 #define T_UI    &unsigned_type_node
 259 #define T89_UI  { STD_C89, NULL, T_UI }
 260 #define T_UL    &long_unsigned_type_node
 261 #define T89_UL  { STD_C89, NULL, T_UL }
 262 #define T_ULL   &long_long_unsigned_type_node
 263 #define T9L_ULL { STD_C9L, NULL, T_ULL }
 264 #define TEX_ULL { STD_EXT, NULL, T_ULL }
 265 #define T_US    &short_unsigned_type_node
 266 #define T89_US  { STD_C89, NULL, T_US }
 267 #define T_F     &float_type_node
 268 #define T89_F   { STD_C89, NULL, T_F }
 269 #define T99_F   { STD_C99, NULL, T_F }
 270 #define T_D     &double_type_node
 271 #define T89_D   { STD_C89, NULL, T_D }
 272 #define T99_D   { STD_C99, NULL, T_D }
 273 #define T_LD    &long_double_type_node
 274 #define T89_LD  { STD_C89, NULL, T_LD }
 275 #define T99_LD  { STD_C99, NULL, T_LD }
 276 #define T_C     &char_type_node
 277 #define T89_C   { STD_C89, NULL, T_C }
 278 #define T_SC    &signed_char_type_node
 279 #define T99_SC  { STD_C99, NULL, T_SC }
 280 #define T_UC    &unsigned_char_type_node
 281 #define T99_UC  { STD_C99, NULL, T_UC }
 282 #define T_V     &void_type_node
 283 #define T89_V   { STD_C89, NULL, T_V }
 284 #define T_W     &wchar_type_node
 285 #define T94_W   { STD_C94, "wchar_t", T_W }
 286 #define TEX_W   { STD_EXT, "wchar_t", T_W }
 287 #define T_WI    &wint_type_node
 288 #define T94_WI  { STD_C94, "wint_t", T_WI }
 289 #define TEX_WI  { STD_EXT, "wint_t", T_WI }
 290 #define T_ST    &size_type_node
 291 #define T99_ST  { STD_C99, "size_t", T_ST }
 292 #define T_SST   &signed_size_type_node
 293 #define T99_SST { STD_C99, "signed size_t", T_SST }
 294 #define T_PD    &ptrdiff_type_node
 295 #define T99_PD  { STD_C99, "ptrdiff_t", T_PD }
 296 #define T_UPD   &unsigned_ptrdiff_type_node
 297 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
 298 #define T_IM    &intmax_type_node
 299 #define T99_IM  { STD_C99, "intmax_t", T_IM }
 300 #define T_UIM   &uintmax_type_node
 301 #define T99_UIM { STD_C99, "uintmax_t", T_UIM }
 302 #define T_D32   &dfloat32_type_node
 303 #define TEX_D32 { STD_EXT, "_Decimal32", T_D32 }
 304 #define T_D64   &dfloat64_type_node
 305 #define TEX_D64 { STD_EXT, "_Decimal64", T_D64 }
 306 #define T_D128  &dfloat128_type_node
 307 #define TEX_D128 { STD_EXT, "_Decimal128", T_D128 }
 308
 309 #endif /* GCC_C_FORMAT_H */