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_H,
  39   FMT_LEN_D,
  40   FMT_LEN_DD,
  41   FMT_LEN_MAX
  42 };
  43
  44
  45 /* The standard versions in which various format features appeared.  */
  46 enum format_std_version
  47 {
  48   STD_C89,
  49   STD_C94,
  50   STD_C9L, /* C99, but treat as C89 if -Wno-long-long.  */
  51   STD_C99,
  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   /* Not included here: details of whether width or precision may occur
  79      (controlled by width_char and precision_char); details of whether
  80      '*' can be used for these (width_type and precision_type); details
  81      of whether length modifiers can occur (length_char_specs).  */
  82 };
  83
  84
  85 /* Structure describing a length modifier supported in format checking, and
  86    possibly a doubled version such as "hh".  */
  87 typedef struct
  88 {
  89   /* Name of the single-character length modifier.  */
  90   const char *name;
  91   /* Index into a format_char_info.types array.  */
  92   enum format_lengths index;
  93   /* Standard version this length appears in.  */
  94   enum format_std_version std;
  95   /* Same, if the modifier can be repeated, or NULL if it can't.  */
  96   const char *double_name;
  97   enum format_lengths double_index;
  98   enum format_std_version double_std;
  99 } format_length_info;
 100
 101
 102 /* Structure describing the combination of a conversion specifier
 103    (or a set of specifiers which act identically) and a length modifier.  */
 104 typedef struct
 105 {
 106   /* The standard version this combination of length and type appeared in.
 107      This is only relevant if greater than those for length and type
 108      individually; otherwise it is ignored.  */
 109   enum format_std_version std;
 110   /* The name to use for the type, if different from that generated internally
 111      (e.g., "signed size_t").  */
 112   const char *name;
 113   /* The type itself.  */
 114   tree *type;
 115 } format_type_detail;
 116
 117
 118 /* Macros to fill out tables of these.  */
 119 #define NOARGUMENTS     { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 120 #define BADLEN  { 0, NULL, NULL }
 121 #define NOLENGTHS       { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 122
 123
 124 /* Structure describing a format conversion specifier (or a set of specifiers
 125    which act identically), and the length modifiers used with it.  */
 126 typedef struct format_char_info
 127 {
 128   const char *format_chars;
 129   int pointer_count;
 130   enum format_std_version std;
 131   /* Types accepted for each length modifier.  */
 132   format_type_detail types[FMT_LEN_MAX];
 133   /* List of other modifier characters allowed with these specifiers.
 134      This lists flags, and additionally "w" for width, "p" for precision
 135      (right precision, for strfmon), "#" for left precision (strfmon),
 136      "a" for scanf "a" allocation extension (not applicable in C99 mode),
 137      "*" for scanf suppression, and "E" and "O" for those strftime
 138      modifiers.  */
 139   const char *flag_chars;
 140   /* List of additional flags describing these conversion specifiers.
 141      "c" for generic character pointers being allowed, "2" for strftime
 142      two digit year formats, "3" for strftime formats giving two digit
 143      years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
 144      "o" if use of strftime "O" is a GNU extension beyond C99,
 145      "W" if the argument is a pointer which is dereferenced and written into,
 146      "R" if the argument is a pointer which is dereferenced and read from,
 147      "i" for printf integer formats where the '0' flag is ignored with
 148      precision, and "[" for the starting character of a scanf scanset.  */
 149   const char *flags2;
 150   /* If this format conversion character consumes more than one argument,
 151      CHAIN points to information about the next argument.  For later
 152      arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags
 153      in FLAGS2 are used.  */
 154   const struct format_char_info *chain;
 155 } format_char_info;
 156
 157
 158 /* Structure describing a flag accepted by some kind of format.  */
 159 typedef struct
 160 {
 161   /* The flag character in question (0 for end of array).  */
 162   int flag_char;
 163   /* Zero if this entry describes the flag character in general, or a
 164      nonzero character that may be found in flags2 if it describes the
 165      flag when used with certain formats only.  If the latter, only
 166      the first such entry found that applies to the current conversion
 167      specifier is used; the values of 'name' and 'long_name' it supplies
 168      will be used, if non-NULL and the standard version is higher than
 169      the unpredicated one, for any pedantic warning.  For example, 'o'
 170      for strftime formats (meaning 'O' is an extension over C99).  */
 171   int predicate;
 172   /* Nonzero if the next character after this flag in the format should
 173      be skipped ('=' in strfmon), zero otherwise.  */
 174   int skip_next_char;
 175   /* The name to use for this flag in diagnostic messages.  For example,
 176      N_("'0' flag"), N_("field width").  */
 177   const char *name;
 178   /* Long name for this flag in diagnostic messages; currently only used for
 179      "ISO C does not support ...".  For example, N_("the 'I' printf flag").  */
 180   const char *long_name;
 181   /* The standard version in which it appeared.  */
 182   enum format_std_version std;
 183 } format_flag_spec;
 184
 185
 186 /* Structure describing a combination of flags that is bad for some kind
 187    of format.  */
 188 typedef struct
 189 {
 190   /* The first flag character in question (0 for end of array).  */
 191   int flag_char1;
 192   /* The second flag character.  */
 193   int flag_char2;
 194   /* Nonzero if the message should say that the first flag is ignored with
 195      the second, zero if the combination should simply be objected to.  */
 196   int ignored;
 197   /* Zero if this entry applies whenever this flag combination occurs,
 198      a nonzero character from flags2 if it only applies in some
 199      circumstances (e.g. 'i' for printf formats ignoring 0 with precision).  */
 200   int predicate;
 201 } format_flag_pair;
 202
 203
 204 /* Structure describing a particular kind of format processed by GCC.  */
 205 typedef struct
 206 {
 207   /* The name of this kind of format, for use in diagnostics.  Also
 208      the name of the attribute (without preceding and following __).  */
 209   const char *name;
 210   /* Specifications of the length modifiers accepted; possibly NULL.  */
 211   const format_length_info *length_char_specs;
 212   /* Details of the conversion specification characters accepted.  */
 213   const format_char_info *conversion_specs;
 214   /* String listing the flag characters that are accepted.  */
 215   const char *flag_chars;
 216   /* String listing modifier characters (strftime) accepted.  May be NULL.  */
 217   const char *modifier_chars;
 218   /* Details of the flag characters, including pseudo-flags.  */
 219   const format_flag_spec *flag_specs;
 220   /* Details of bad combinations of flags.  */
 221   const format_flag_pair *bad_flag_pairs;
 222   /* Flags applicable to this kind of format.  */
 223   int flags;
 224   /* Flag character to treat a width as, or 0 if width not used.  */
 225   int width_char;
 226   /* Flag character to treat a left precision (strfmon) as,
 227      or 0 if left precision not used.  */
 228   int left_precision_char;
 229   /* Flag character to treat a precision (for strfmon, right precision) as,
 230      or 0 if precision not used.  */
 231   int precision_char;
 232   /* If a flag character has the effect of suppressing the conversion of
 233      an argument ('*' in scanf), that flag character, otherwise 0.  */
 234   int suppression_char;
 235   /* Flag character to treat a length modifier as (ignored if length
 236      modifiers not used).  Need not be placed in flag_chars for conversion
 237      specifiers, but is used to check for bad combinations such as length
 238      modifier with assignment suppression in scanf.  */
 239   int length_code_char;
 240   /* Pointer to type of argument expected if '*' is used for a width,
 241      or NULL if '*' not used for widths.  */
 242   tree *width_type;
 243   /* Pointer to type of argument expected if '*' is used for a precision,
 244      or NULL if '*' not used for precisions.  */
 245   tree *precision_type;
 246 } format_kind_info;
 247
 248 #define T_I     &integer_type_node
 249 #define T89_I   { STD_C89, NULL, T_I }
 250 #define T_L     &long_integer_type_node
 251 #define T89_L   { STD_C89, NULL, T_L }
 252 #define T_LL    &long_long_integer_type_node
 253 #define T9L_LL  { STD_C9L, NULL, T_LL }
 254 #define TEX_LL  { STD_EXT, NULL, T_LL }
 255 #define T_S     &short_integer_type_node
 256 #define T89_S   { STD_C89, NULL, T_S }
 257 #define T_UI    &unsigned_type_node
 258 #define T89_UI  { STD_C89, NULL, T_UI }
 259 #define T_UL    &long_unsigned_type_node
 260 #define T89_UL  { STD_C89, NULL, T_UL }
 261 #define T_ULL   &long_long_unsigned_type_node
 262 #define T9L_ULL { STD_C9L, NULL, T_ULL }
 263 #define TEX_ULL { STD_EXT, NULL, T_ULL }
 264 #define T_US    &short_unsigned_type_node
 265 #define T89_US  { STD_C89, NULL, T_US }
 266 #define T_F     &float_type_node
 267 #define T89_F   { STD_C89, NULL, T_F }
 268 #define T99_F   { STD_C99, NULL, T_F }
 269 #define T_D     &double_type_node
 270 #define T89_D   { STD_C89, NULL, T_D }
 271 #define T99_D   { STD_C99, NULL, T_D }
 272 #define T_LD    &long_double_type_node
 273 #define T89_LD  { STD_C89, NULL, T_LD }
 274 #define T99_LD  { STD_C99, NULL, T_LD }
 275 #define T_C     &char_type_node
 276 #define T89_C   { STD_C89, NULL, T_C }
 277 #define T_SC    &signed_char_type_node
 278 #define T99_SC  { STD_C99, NULL, T_SC }
 279 #define T_UC    &unsigned_char_type_node
 280 #define T99_UC  { STD_C99, NULL, T_UC }
 281 #define T_V     &void_type_node
 282 #define T89_V   { STD_C89, NULL, T_V }
 283 #define T_W     &wchar_type_node
 284 #define T94_W   { STD_C94, "wchar_t", T_W }
 285 #define TEX_W   { STD_EXT, "wchar_t", T_W }
 286 #define T_WI    &wint_type_node
 287 #define T94_WI  { STD_C94, "wint_t", T_WI }
 288 #define TEX_WI  { STD_EXT, "wint_t", T_WI }
 289 #define T_ST    &size_type_node
 290 #define T99_ST  { STD_C99, "size_t", T_ST }
 291 #define T_SST   &signed_size_type_node
 292 #define T99_SST { STD_C99, "signed size_t", T_SST }
 293 #define T_PD    &ptrdiff_type_node
 294 #define T99_PD  { STD_C99, "ptrdiff_t", T_PD }
 295 #define T_UPD   &unsigned_ptrdiff_type_node
 296 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
 297 #define T_IM    &intmax_type_node
 298 #define T99_IM  { STD_C99, "intmax_t", T_IM }
 299 #define T_UIM   &uintmax_type_node
 300 #define T99_UIM { STD_C99, "uintmax_t", T_UIM }
 301 #define T_D32   &dfloat32_type_node
 302 #define TEX_D32 { STD_EXT, "_Decimal32", T_D32 }
 303 #define T_D64   &dfloat64_type_node
 304 #define TEX_D64 { STD_EXT, "_Decimal64", T_D64 }
 305 #define T_D128  &dfloat128_type_node
 306 #define TEX_D128 { STD_EXT, "_Decimal128", T_D128 }
 307
 308 #endif /* GCC_C_FORMAT_H */