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 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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #ifndef GCC_C_FORMAT_H
  23 #define GCC_C_FORMAT_H
  24
  25 /* The meaningfully distinct length modifiers for format checking recognized
  26    by GCC.  */
  27 enum format_lengths
  28 {
  29   FMT_LEN_none,
  30   FMT_LEN_hh,
  31   FMT_LEN_h,
  32   FMT_LEN_l,
  33   FMT_LEN_ll,
  34   FMT_LEN_L,
  35   FMT_LEN_z,
  36   FMT_LEN_t,
  37   FMT_LEN_j,
  38   FMT_LEN_MAX
  39 };
  40
  41
  42 /* The standard versions in which various format features appeared.  */
  43 enum format_std_version
  44 {
  45   STD_C89,
  46   STD_C94,
  47   STD_C9L, /* C99, but treat as C89 if -Wno-long-long.  */
  48   STD_C99,
  49   STD_EXT
  50 };
  51
  52 /* Flags that may apply to a particular kind of format checked by GCC.  */
  53 enum
  54 {
  55   /* This format converts arguments of types determined by the
  56      format string.  */
  57   FMT_FLAG_ARG_CONVERT = 1,
  58   /* The scanf allocation 'a' kludge applies to this format kind.  */
  59   FMT_FLAG_SCANF_A_KLUDGE = 2,
  60   /* A % during parsing a specifier is allowed to be a modified % rather
  61      that indicating the format is broken and we are out-of-sync.  */
  62   FMT_FLAG_FANCY_PERCENT_OK = 4,
  63   /* With $ operand numbers, it is OK to reference the same argument more
  64      than once.  */
  65   FMT_FLAG_DOLLAR_MULTIPLE = 8,
  66   /* This format type uses $ operand numbers (strfmon doesn't).  */
  67   FMT_FLAG_USE_DOLLAR = 16,
  68   /* Zero width is bad in this type of format (scanf).  */
  69   FMT_FLAG_ZERO_WIDTH_BAD = 32,
  70   /* Empty precision specification is OK in this type of format (printf).  */
  71   FMT_FLAG_EMPTY_PREC_OK = 64,
  72   /* Gaps are allowed in the arguments with $ operand numbers if all
  73      arguments are pointers (scanf).  */
  74   FMT_FLAG_DOLLAR_GAP_POINTER_OK = 128
  75   /* Not included here: details of whether width or precision may occur
  76      (controlled by width_char and precision_char); details of whether
  77      '*' can be used for these (width_type and precision_type); details
  78      of whether length modifiers can occur (length_char_specs).  */
  79 };
  80
  81
  82 /* Structure describing a length modifier supported in format checking, and
  83    possibly a doubled version such as "hh".  */
  84 typedef struct
  85 {
  86   /* Name of the single-character length modifier.  */
  87   const char *name;
  88   /* Index into a format_char_info.types array.  */
  89   enum format_lengths index;
  90   /* Standard version this length appears in.  */
  91   enum format_std_version std;
  92   /* Same, if the modifier can be repeated, or NULL if it can't.  */
  93   const char *double_name;
  94   enum format_lengths double_index;
  95   enum format_std_version double_std;
  96 } format_length_info;
  97
  98
  99 /* Structure describing the combination of a conversion specifier
 100    (or a set of specifiers which act identically) and a length modifier.  */
 101 typedef struct
 102 {
 103   /* The standard version this combination of length and type appeared in.
 104      This is only relevant if greater than those for length and type
 105      individually; otherwise it is ignored.  */
 106   enum format_std_version std;
 107   /* The name to use for the type, if different from that generated internally
 108      (e.g., "signed size_t").  */
 109   const char *name;
 110   /* The type itself.  */
 111   tree *type;
 112 } format_type_detail;
 113
 114
 115 /* Macros to fill out tables of these.  */
 116 #define NOARGUMENTS     { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 117 #define BADLEN  { 0, NULL, NULL }
 118 #define NOLENGTHS       { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 119
 120
 121 /* Structure describing a format conversion specifier (or a set of specifiers
 122    which act identically), and the length modifiers used with it.  */
 123 typedef struct format_char_info
 124 {
 125   const char *format_chars;
 126   int pointer_count;
 127   enum format_std_version std;
 128   /* Types accepted for each length modifier.  */
 129   format_type_detail types[FMT_LEN_MAX];
 130   /* List of other modifier characters allowed with these specifiers.
 131      This lists flags, and additionally "w" for width, "p" for precision
 132      (right precision, for strfmon), "#" for left precision (strfmon),
 133      "a" for scanf "a" allocation extension (not applicable in C99 mode),
 134      "*" for scanf suppression, and "E" and "O" for those strftime
 135      modifiers.  */
 136   const char *flag_chars;
 137   /* List of additional flags describing these conversion specifiers.
 138      "c" for generic character pointers being allowed, "2" for strftime
 139      two digit year formats, "3" for strftime formats giving two digit
 140      years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
 141      "o" if use of strftime "O" is a GNU extension beyond C99,
 142      "W" if the argument is a pointer which is dereferenced and written into,
 143      "R" if the argument is a pointer which is dereferenced and read from,
 144      "i" for printf integer formats where the '0' flag is ignored with
 145      precision, and "[" for the starting character of a scanf scanset.  */
 146   const char *flags2;
 147   /* If this format conversion character consumes more than one argument,
 148      CHAIN points to information about the next argument.  For later
 149      arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags
 150      in FLAGS2 are used.  */
 151   const struct format_char_info *chain;
 152 } format_char_info;
 153
 154
 155 /* Structure describing a flag accepted by some kind of format.  */
 156 typedef struct
 157 {
 158   /* The flag character in question (0 for end of array).  */
 159   int flag_char;
 160   /* Zero if this entry describes the flag character in general, or a
 161      nonzero character that may be found in flags2 if it describes the
 162      flag when used with certain formats only.  If the latter, only
 163      the first such entry found that applies to the current conversion
 164      specifier is used; the values of 'name' and 'long_name' it supplies
 165      will be used, if non-NULL and the standard version is higher than
 166      the unpredicated one, for any pedantic warning.  For example, 'o'
 167      for strftime formats (meaning 'O' is an extension over C99).  */
 168   int predicate;
 169   /* Nonzero if the next character after this flag in the format should
 170      be skipped ('=' in strfmon), zero otherwise.  */
 171   int skip_next_char;
 172   /* The name to use for this flag in diagnostic messages.  For example,
 173      N_("'0' flag"), N_("field width").  */
 174   const char *name;
 175   /* Long name for this flag in diagnostic messages; currently only used for
 176      "ISO C does not support ...".  For example, N_("the 'I' printf flag").  */
 177   const char *long_name;
 178   /* The standard version in which it appeared.  */
 179   enum format_std_version std;
 180 } format_flag_spec;
 181
 182
 183 /* Structure describing a combination of flags that is bad for some kind
 184    of format.  */
 185 typedef struct
 186 {
 187   /* The first flag character in question (0 for end of array).  */
 188   int flag_char1;
 189   /* The second flag character.  */
 190   int flag_char2;
 191   /* Nonzero if the message should say that the first flag is ignored with
 192      the second, zero if the combination should simply be objected to.  */
 193   int ignored;
 194   /* Zero if this entry applies whenever this flag combination occurs,
 195      a nonzero character from flags2 if it only applies in some
 196      circumstances (e.g. 'i' for printf formats ignoring 0 with precision).  */
 197   int predicate;
 198 } format_flag_pair;
 199
 200
 201 /* Structure describing a particular kind of format processed by GCC.  */
 202 typedef struct
 203 {
 204   /* The name of this kind of format, for use in diagnostics.  Also
 205      the name of the attribute (without preceding and following __).  */
 206   const char *name;
 207   /* Specifications of the length modifiers accepted; possibly NULL.  */
 208   const format_length_info *length_char_specs;
 209   /* Details of the conversion specification characters accepted.  */
 210   const format_char_info *conversion_specs;
 211   /* String listing the flag characters that are accepted.  */
 212   const char *flag_chars;
 213   /* String listing modifier characters (strftime) accepted.  May be NULL.  */
 214   const char *modifier_chars;
 215   /* Details of the flag characters, including pseudo-flags.  */
 216   const format_flag_spec *flag_specs;
 217   /* Details of bad combinations of flags.  */
 218   const format_flag_pair *bad_flag_pairs;
 219   /* Flags applicable to this kind of format.  */
 220   int flags;
 221   /* Flag character to treat a width as, or 0 if width not used.  */
 222   int width_char;
 223   /* Flag character to treat a left precision (strfmon) as,
 224      or 0 if left precision not used.  */
 225   int left_precision_char;
 226   /* Flag character to treat a precision (for strfmon, right precision) as,
 227      or 0 if precision not used.  */
 228   int precision_char;
 229   /* If a flag character has the effect of suppressing the conversion of
 230      an argument ('*' in scanf), that flag character, otherwise 0.  */
 231   int suppression_char;
 232   /* Flag character to treat a length modifier as (ignored if length
 233      modifiers not used).  Need not be placed in flag_chars for conversion
 234      specifiers, but is used to check for bad combinations such as length
 235      modifier with assignment suppression in scanf.  */
 236   int length_code_char;
 237   /* Pointer to type of argument expected if '*' is used for a width,
 238      or NULL if '*' not used for widths.  */
 239   tree *width_type;
 240   /* Pointer to type of argument expected if '*' is used for a precision,
 241      or NULL if '*' not used for precisions.  */
 242   tree *precision_type;
 243 } format_kind_info;
 244
 245 #define T_I     &integer_type_node
 246 #define T89_I   { STD_C89, NULL, T_I }
 247 #define T_L     &long_integer_type_node
 248 #define T89_L   { STD_C89, NULL, T_L }
 249 #define T_LL    &long_long_integer_type_node
 250 #define T9L_LL  { STD_C9L, NULL, T_LL }
 251 #define TEX_LL  { STD_EXT, NULL, T_LL }
 252 #define T_S     &short_integer_type_node
 253 #define T89_S   { STD_C89, NULL, T_S }
 254 #define T_UI    &unsigned_type_node
 255 #define T89_UI  { STD_C89, NULL, T_UI }
 256 #define T_UL    &long_unsigned_type_node
 257 #define T89_UL  { STD_C89, NULL, T_UL }
 258 #define T_ULL   &long_long_unsigned_type_node
 259 #define T9L_ULL { STD_C9L, NULL, T_ULL }
 260 #define TEX_ULL { STD_EXT, NULL, T_ULL }
 261 #define T_US    &short_unsigned_type_node
 262 #define T89_US  { STD_C89, NULL, T_US }
 263 #define T_F     &float_type_node
 264 #define T89_F   { STD_C89, NULL, T_F }
 265 #define T99_F   { STD_C99, NULL, T_F }
 266 #define T_D     &double_type_node
 267 #define T89_D   { STD_C89, NULL, T_D }
 268 #define T99_D   { STD_C99, NULL, T_D }
 269 #define T_LD    &long_double_type_node
 270 #define T89_LD  { STD_C89, NULL, T_LD }
 271 #define T99_LD  { STD_C99, NULL, T_LD }
 272 #define T_C     &char_type_node
 273 #define T89_C   { STD_C89, NULL, T_C }
 274 #define T_SC    &signed_char_type_node
 275 #define T99_SC  { STD_C99, NULL, T_SC }
 276 #define T_UC    &unsigned_char_type_node
 277 #define T99_UC  { STD_C99, NULL, T_UC }
 278 #define T_V     &void_type_node
 279 #define T89_V   { STD_C89, NULL, T_V }
 280 #define T_W     &wchar_type_node
 281 #define T94_W   { STD_C94, "wchar_t", T_W }
 282 #define TEX_W   { STD_EXT, "wchar_t", T_W }
 283 #define T_WI    &wint_type_node
 284 #define T94_WI  { STD_C94, "wint_t", T_WI }
 285 #define TEX_WI  { STD_EXT, "wint_t", T_WI }
 286 #define T_ST    &size_type_node
 287 #define T99_ST  { STD_C99, "size_t", T_ST }
 288 #define T_SST   &signed_size_type_node
 289 #define T99_SST { STD_C99, "signed size_t", T_SST }
 290 #define T_PD    &ptrdiff_type_node
 291 #define T99_PD  { STD_C99, "ptrdiff_t", T_PD }
 292 #define T_UPD   &unsigned_ptrdiff_type_node
 293 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
 294 #define T_IM    &intmax_type_node
 295 #define T99_IM  { STD_C99, "intmax_t", T_IM }
 296 #define T_UIM   &uintmax_type_node
 297 #define T99_UIM { STD_C99, "uintmax_t", T_UIM }
 298
 299 #endif /* GCC_C_FORMAT_H */