gcc/c-family/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, 2008, 2010 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   /* The format arg is an opaque object that will be parsed by an external
  78      facility.  */
  79   FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL = 256
  80   /* Not included here: details of whether width or precision may occur
  81      (controlled by width_char and precision_char); details of whether
  82      '*' can be used for these (width_type and precision_type); details
  83      of whether length modifiers can occur (length_char_specs).  */
  84 };
  85
  86 /* Structure describing a length modifier supported in format checking, and
  87    possibly a doubled version such as "hh".  */
  88 typedef struct
  89 {
  90   /* Name of the single-character length modifier. If prefixed by
  91      a zero character, it describes a multi character length
  92      modifier, like I64, I32, etc.  */
  93   const char *name;
  94   /* Index into a format_char_info.types array.  */
  95   enum format_lengths index;
  96   /* Standard version this length appears in.  */
  97   enum format_std_version std;
  98   /* Same, if the modifier can be repeated, or NULL if it can't.  */
  99   const char *double_name;
 100   enum format_lengths double_index;
 101   enum format_std_version double_std;
 102
 103   /* If this flag is set, just scalar width identity is checked, and
 104      not the type identity itself.  */
 105   int scalar_identity_flag;
 106 } format_length_info;
 107
 108
 109 /* Structure describing the combination of a conversion specifier
 110    (or a set of specifiers which act identically) and a length modifier.  */
 111 typedef struct
 112 {
 113   /* The standard version this combination of length and type appeared in.
 114      This is only relevant if greater than those for length and type
 115      individually; otherwise it is ignored.  */
 116   enum format_std_version std;
 117   /* The name to use for the type, if different from that generated internally
 118      (e.g., "signed size_t").  */
 119   const char *name;
 120   /* The type itself.  */
 121   tree *type;
 122 } format_type_detail;
 123
 124
 125 /* Macros to fill out tables of these.  */
 126 #define NOARGUMENTS     { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 127 #define BADLEN  { STD_C89, NULL, NULL }
 128 #define NOLENGTHS       { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
 129
 130
 131 /* Structure describing a format conversion specifier (or a set of specifiers
 132    which act identically), and the length modifiers used with it.  */
 133 typedef struct format_char_info
 134 {
 135   const char *format_chars;
 136   int pointer_count;
 137   enum format_std_version std;
 138   /* Types accepted for each length modifier.  */
 139   format_type_detail types[FMT_LEN_MAX];
 140   /* List of other modifier characters allowed with these specifiers.
 141      This lists flags, and additionally "w" for width, "p" for precision
 142      (right precision, for strfmon), "#" for left precision (strfmon),
 143      "a" for scanf "a" allocation extension (not applicable in C99 mode),
 144      "*" for scanf suppression, and "E" and "O" for those strftime
 145      modifiers.  */
 146   const char *flag_chars;
 147   /* List of additional flags describing these conversion specifiers.
 148      "c" for generic character pointers being allowed, "2" for strftime
 149      two digit year formats, "3" for strftime formats giving two digit
 150      years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
 151      "o" if use of strftime "O" is a GNU extension beyond C99,
 152      "W" if the argument is a pointer which is dereferenced and written into,
 153      "R" if the argument is a pointer which is dereferenced and read from,
 154      "i" for printf integer formats where the '0' flag is ignored with
 155      precision, and "[" for the starting character of a scanf scanset.  */
 156   const char *flags2;
 157   /* If this format conversion character consumes more than one argument,
 158      CHAIN points to information about the next argument.  For later
 159      arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags
 160      in FLAGS2 are used.  */
 161   const struct format_char_info *chain;
 162 } format_char_info;
 163
 164
 165 /* Structure describing a flag accepted by some kind of format.  */
 166 typedef struct
 167 {
 168   /* The flag character in question (0 for end of array).  */
 169   int flag_char;
 170   /* Zero if this entry describes the flag character in general, or a
 171      nonzero character that may be found in flags2 if it describes the
 172      flag when used with certain formats only.  If the latter, only
 173      the first such entry found that applies to the current conversion
 174      specifier is used; the values of 'name' and 'long_name' it supplies
 175      will be used, if non-NULL and the standard version is higher than
 176      the unpredicated one, for any pedantic warning.  For example, 'o'
 177      for strftime formats (meaning 'O' is an extension over C99).  */
 178   int predicate;
 179   /* Nonzero if the next character after this flag in the format should
 180      be skipped ('=' in strfmon), zero otherwise.  */
 181   int skip_next_char;
 182   /* The name to use for this flag in diagnostic messages.  For example,
 183      N_("'0' flag"), N_("field width").  */
 184   const char *name;
 185   /* Long name for this flag in diagnostic messages; currently only used for
 186      "ISO C does not support ...".  For example, N_("the 'I' printf flag").  */
 187   const char *long_name;
 188   /* The standard version in which it appeared.  */
 189   enum format_std_version std;
 190 } format_flag_spec;
 191
 192
 193 /* Structure describing a combination of flags that is bad for some kind
 194    of format.  */
 195 typedef struct
 196 {
 197   /* The first flag character in question (0 for end of array).  */
 198   int flag_char1;
 199   /* The second flag character.  */
 200   int flag_char2;
 201   /* Nonzero if the message should say that the first flag is ignored with
 202      the second, zero if the combination should simply be objected to.  */
 203   int ignored;
 204   /* Zero if this entry applies whenever this flag combination occurs,
 205      a nonzero character from flags2 if it only applies in some
 206      circumstances (e.g. 'i' for printf formats ignoring 0 with precision).  */
 207   int predicate;
 208 } format_flag_pair;
 209
 210
 211 /* Structure describing a particular kind of format processed by GCC.  */
 212 typedef struct
 213 {
 214   /* The name of this kind of format, for use in diagnostics.  Also
 215      the name of the attribute (without preceding and following __).  */
 216   const char *name;
 217   /* Specifications of the length modifiers accepted; possibly NULL.  */
 218   const format_length_info *length_char_specs;
 219   /* Details of the conversion specification characters accepted.  */
 220   const format_char_info *conversion_specs;
 221   /* String listing the flag characters that are accepted.  */
 222   const char *flag_chars;
 223   /* String listing modifier characters (strftime) accepted.  May be NULL.  */
 224   const char *modifier_chars;
 225   /* Details of the flag characters, including pseudo-flags.  */
 226   const format_flag_spec *flag_specs;
 227   /* Details of bad combinations of flags.  */
 228   const format_flag_pair *bad_flag_pairs;
 229   /* Flags applicable to this kind of format.  */
 230   int flags;
 231   /* Flag character to treat a width as, or 0 if width not used.  */
 232   int width_char;
 233   /* Flag character to treat a left precision (strfmon) as,
 234      or 0 if left precision not used.  */
 235   int left_precision_char;
 236   /* Flag character to treat a precision (for strfmon, right precision) as,
 237      or 0 if precision not used.  */
 238   int precision_char;
 239   /* If a flag character has the effect of suppressing the conversion of
 240      an argument ('*' in scanf), that flag character, otherwise 0.  */
 241   int suppression_char;
 242   /* Flag character to treat a length modifier as (ignored if length
 243      modifiers not used).  Need not be placed in flag_chars for conversion
 244      specifiers, but is used to check for bad combinations such as length
 245      modifier with assignment suppression in scanf.  */
 246   int length_code_char;
 247   /* Assignment-allocation flag character ('m' in scanf), otherwise 0.  */
 248   int alloc_char;
 249   /* Pointer to type of argument expected if '*' is used for a width,
 250      or NULL if '*' not used for widths.  */
 251   tree *width_type;
 252   /* Pointer to type of argument expected if '*' is used for a precision,
 253      or NULL if '*' not used for precisions.  */
 254   tree *precision_type;
 255 } format_kind_info;
 256
 257 #define T_I     &integer_type_node
 258 #define T89_I   { STD_C89, NULL, T_I }
 259 #define T_L     &long_integer_type_node
 260 #define T89_L   { STD_C89, NULL, T_L }
 261 #define T_LL    &long_long_integer_type_node
 262 #define T9L_LL  { STD_C9L, NULL, T_LL }
 263 #define TEX_LL  { STD_EXT, NULL, T_LL }
 264 #define T_S     &short_integer_type_node
 265 #define T89_S   { STD_C89, NULL, T_S }
 266 #define T_UI    &unsigned_type_node
 267 #define T89_UI  { STD_C89, NULL, T_UI }
 268 #define T_UL    &long_unsigned_type_node
 269 #define T89_UL  { STD_C89, NULL, T_UL }
 270 #define T_ULL   &long_long_unsigned_type_node
 271 #define T9L_ULL { STD_C9L, NULL, T_ULL }
 272 #define TEX_ULL { STD_EXT, NULL, T_ULL }
 273 #define T_US    &short_unsigned_type_node
 274 #define T89_US  { STD_C89, NULL, T_US }
 275 #define T_F     &float_type_node
 276 #define T89_F   { STD_C89, NULL, T_F }
 277 #define T99_F   { STD_C99, NULL, T_F }
 278 #define T_D     &double_type_node
 279 #define T89_D   { STD_C89, NULL, T_D }
 280 #define T99_D   { STD_C99, NULL, T_D }
 281 #define T_LD    &long_double_type_node
 282 #define T89_LD  { STD_C89, NULL, T_LD }
 283 #define T99_LD  { STD_C99, NULL, T_LD }
 284 #define T_C     &char_type_node
 285 #define T89_C   { STD_C89, NULL, T_C }
 286 #define T_SC    &signed_char_type_node
 287 #define T99_SC  { STD_C99, NULL, T_SC }
 288 #define T_UC    &unsigned_char_type_node
 289 #define T99_UC  { STD_C99, NULL, T_UC }
 290 #define T_V     &void_type_node
 291 #define T89_V   { STD_C89, NULL, T_V }
 292 #define T_W     &wchar_type_node
 293 #define T94_W   { STD_C94, "wchar_t", T_W }
 294 #define TEX_W   { STD_EXT, "wchar_t", T_W }
 295 #define T_WI    &wint_type_node
 296 #define T94_WI  { STD_C94, "wint_t", T_WI }
 297 #define TEX_WI  { STD_EXT, "wint_t", T_WI }
 298 #define T_ST    &size_type_node
 299 #define T99_ST  { STD_C99, "size_t", T_ST }
 300 #define T_SST   &signed_size_type_node
 301 #define T99_SST { STD_C99, "signed size_t", T_SST }
 302 #define T_PD    &ptrdiff_type_node
 303 #define T99_PD  { STD_C99, "ptrdiff_t", T_PD }
 304 #define T_UPD   &unsigned_ptrdiff_type_node
 305 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
 306 #define T_IM    &intmax_type_node
 307 #define T99_IM  { STD_C99, "intmax_t", T_IM }
 308 #define T_UIM   &uintmax_type_node
 309 #define T99_UIM { STD_C99, "uintmax_t", T_UIM }
 310 #define T_D32   &dfloat32_type_node
 311 #define TEX_D32 { STD_EXT, "_Decimal32", T_D32 }
 312 #define T_D64   &dfloat64_type_node
 313 #define TEX_D64 { STD_EXT, "_Decimal64", T_D64 }
 314 #define T_D128  &dfloat128_type_node
 315 #define TEX_D128 { STD_EXT, "_Decimal128", T_D128 }
 316
 317 /* Structure describing how format attributes such as "printf" are
 318    interpreted as "gnu_printf" or "ms_printf" on a particular system.
 319    TARGET_OVERRIDES_FORMAT_ATTRIBUTES is used to specify target-specific
 320    defaults.  */
 321 typedef struct
 322 {
 323   /* The name of the to be copied format attribute. */
 324   const char *named_attr_src;
 325   /* The name of the to be overridden format attribute. */
 326   const char *named_attr_dst;
 327 } target_ovr_attr;
 328
 329 #endif /* GCC_C_FORMAT_H */