1/* Check calls to formatted I/O functions (-Wformat).
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along 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. */
25enum 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. */
44enum 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. */
54enum
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};
84
85/* Structure describing a length modifier supported in format checking, and
86 possibly a doubled version such as "hh". */
87struct format_length_info
88{
89 /* Name of the single-character length modifier. If prefixed by
90 a zero character, it describes a multi character length
91 modifier, like I64, I32, etc. */
92 const char *name;
93 /* Index into a format_char_info.types array. */
94 enum format_lengths index;
95 /* Standard version this length appears in. */
96 enum format_std_version std;
97 /* Same, if the modifier can be repeated, or NULL if it can't. */
98 const char *double_name;
99 enum format_lengths double_index;
100 enum format_std_version double_std;
101
102 /* If this flag is set, just scalar width identity is checked, and
103 not the type identity itself. */
104 int scalar_identity_flag;
105};
106
107
108/* Structure describing the combination of a conversion specifier
109 (or a set of specifiers which act identically) and a length modifier. */
110struct format_type_detail
111{
112 /* The standard version this combination of length and type appeared in.
113 This is only relevant if greater than those for length and type
114 individually; otherwise it is ignored. */
115 enum format_std_version std;
116 /* The name to use for the type, if different from that generated internally
117 (e.g., "signed size_t"). */
118 const char *name;
119 /* The type itself. */
120 tree *type;
121};
122
123
124/* Macros to fill out tables of these. */
125#define NOARGUMENTS { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
126#define BADLEN { STD_C89, NULL, NULL }
127#define NOLENGTHS { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
128
129
130/* Structure describing a format conversion specifier (or a set of specifiers
131 which act identically), and the length modifiers used with it. */
132struct format_char_info
133{
134 const char *format_chars;
135 int pointer_count;
136 enum format_std_version std;
137 /* Types accepted for each length modifier. */
138 format_type_detail types[FMT_LEN_MAX];
139 /* List of other modifier characters allowed with these specifiers.
140 This lists flags, and additionally "w" for width, "p" for precision
141 (right precision, for strfmon), "#" for left precision (strfmon),
142 "a" for scanf "a" allocation extension (not applicable in C99 mode),
143 "*" for scanf suppression, and "E" and "O" for those strftime
144 modifiers. */
145 const char *flag_chars;
146 /* List of additional flags describing these conversion specifiers.
147 "c" for generic character pointers being allowed, "2" for strftime
148 two digit year formats, "3" for strftime formats giving two digit
149 years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
150 "o" if use of strftime "O" is a GNU extension beyond C99,
151 "W" if the argument is a pointer which is dereferenced and written into,
152 "R" if the argument is a pointer which is dereferenced and read from,
153 "i" for printf integer formats where the '0' flag is ignored with
154 precision, and "[" for the starting character of a scanf scanset,
155 "<" if the specifier introduces a quoted sequence (such as "%<"),
156 ">" if the specifier terminates a quoted sequence (such as "%>"),
157 "[" if the specifier introduces a color sequence (such as "%r"),
158 "]" if the specifier terminates a color sequence (such as "%R"),
159 "'" (single quote) if the specifier is expected to be quoted when
160 it appears outside a quoted sequence and unquoted otherwise (such
161 as the GCC internal printf format directive "%T"), and
162 "\"" (double quote) if the specifier is not expected to appear in
163 a quoted sequence (such as the GCC internal format directive "%K". */
164 const char *flags2;
165 /* If this format conversion character consumes more than one argument,
166 CHAIN points to information about the next argument. For later
167 arguments, only POINTER_COUNT, TYPES, and the "c", "R", and "W" flags
168 in FLAGS2 are used. */
169 const struct format_char_info *chain;
170};
171
172
173/* Structure describing a flag accepted by some kind of format. */
174struct format_flag_spec
175{
176 /* The flag character in question (0 for end of array). */
177 int flag_char;
178 /* Zero if this entry describes the flag character in general, or a
179 nonzero character that may be found in flags2 if it describes the
180 flag when used with certain formats only. If the latter, only
181 the first such entry found that applies to the current conversion
182 specifier is used; the values of 'name' and 'long_name' it supplies
183 will be used, if non-NULL and the standard version is higher than
184 the unpredicated one, for any pedantic warning. For example, 'o'
185 for strftime formats (meaning 'O' is an extension over C99). */
186 int predicate;
187 /* Nonzero if the next character after this flag in the format should
188 be skipped ('=' in strfmon), zero otherwise. */
189 int skip_next_char;
190 /* True if the flag introduces quoting (as in GCC's %qE). */
191 bool quoting;
192 /* The name to use for this flag in diagnostic messages. For example,
193 N_("'0' flag"), N_("field width"). */
194 const char *name;
195 /* Long name for this flag in diagnostic messages; currently only used for
196 "ISO C does not support ...". For example, N_("the 'I' printf flag"). */
197 const char *long_name;
198 /* The standard version in which it appeared. */
199 enum format_std_version std;
200};
201
202
203/* Structure describing a combination of flags that is bad for some kind
204 of format. */
205struct format_flag_pair
206{
207 /* The first flag character in question (0 for end of array). */
208 int flag_char1;
209 /* The second flag character. */
210 int flag_char2;
211 /* Nonzero if the message should say that the first flag is ignored with
212 the second, zero if the combination should simply be objected to. */
213 int ignored;
214 /* Zero if this entry applies whenever this flag combination occurs,
215 a nonzero character from flags2 if it only applies in some
216 circumstances (e.g. 'i' for printf formats ignoring 0 with precision). */
217 int predicate;
218};
219
220
221/* Structure describing a particular kind of format processed by GCC. */
222struct format_kind_info
223{
224 /* The name of this kind of format, for use in diagnostics. Also
225 the name of the attribute (without preceding and following __). */
226 const char *name;
227 /* Specifications of the length modifiers accepted; possibly NULL. */
228 const format_length_info *length_char_specs;
229 /* Details of the conversion specification characters accepted. */
230 const format_char_info *conversion_specs;
231 /* String listing the flag characters that are accepted. */
232 const char *flag_chars;
233 /* String listing modifier characters (strftime) accepted. May be NULL. */
234 const char *modifier_chars;
235 /* Details of the flag characters, including pseudo-flags. */
236 const format_flag_spec *flag_specs;
237 /* Details of bad combinations of flags. */
238 const format_flag_pair *bad_flag_pairs;
239 /* Flags applicable to this kind of format. */
240 int flags;
241 /* Flag character to treat a width as, or 0 if width not used. */
242 int width_char;
243 /* Flag character to treat a left precision (strfmon) as,
244 or 0 if left precision not used. */
245 int left_precision_char;
246 /* Flag character to treat a precision (for strfmon, right precision) as,
247 or 0 if precision not used. */
248 int precision_char;
249 /* If a flag character has the effect of suppressing the conversion of
250 an argument ('*' in scanf), that flag character, otherwise 0. */
251 int suppression_char;
252 /* Flag character to treat a length modifier as (ignored if length
253 modifiers not used). Need not be placed in flag_chars for conversion
254 specifiers, but is used to check for bad combinations such as length
255 modifier with assignment suppression in scanf. */
256 int length_code_char;
257 /* Assignment-allocation flag character ('m' in scanf), otherwise 0. */
258 int alloc_char;
259 /* Pointer to type of argument expected if '*' is used for a width,
260 or NULL if '*' not used for widths. */
261 tree *width_type;
262 /* Pointer to type of argument expected if '*' is used for a precision,
263 or NULL if '*' not used for precisions. */
264 tree *precision_type;
265};
266
267#define T_I &integer_type_node
268#define T89_I { STD_C89, NULL, T_I }
269#define T_L &long_integer_type_node
270#define T89_L { STD_C89, NULL, T_L }
271#define T_LL &long_long_integer_type_node
272#define T9L_LL { STD_C9L, NULL, T_LL }
273#define TEX_LL { STD_EXT, NULL, T_LL }
274#define T_S &short_integer_type_node
275#define T89_S { STD_C89, NULL, T_S }
276#define T_UI &unsigned_type_node
277#define T89_UI { STD_C89, NULL, T_UI }
278#define T_UL &long_unsigned_type_node
279#define T89_UL { STD_C89, NULL, T_UL }
280#define T_ULL &long_long_unsigned_type_node
281#define T9L_ULL { STD_C9L, NULL, T_ULL }
282#define TEX_ULL { STD_EXT, NULL, T_ULL }
283#define T_US &short_unsigned_type_node
284#define T89_US { STD_C89, NULL, T_US }
285#define T_F &float_type_node
286#define T89_F { STD_C89, NULL, T_F }
287#define T99_F { STD_C99, NULL, T_F }
288#define T_D &double_type_node
289#define T89_D { STD_C89, NULL, T_D }
290#define T99_D { STD_C99, NULL, T_D }
291#define T_LD &long_double_type_node
292#define T89_LD { STD_C89, NULL, T_LD }
293#define T99_LD { STD_C99, NULL, T_LD }
294#define T_C &char_type_node
295#define T89_C { STD_C89, NULL, T_C }
296#define T_SC &signed_char_type_node
297#define T99_SC { STD_C99, NULL, T_SC }
298#define T_UC &unsigned_char_type_node
299#define T99_UC { STD_C99, NULL, T_UC }
300#define T_V &void_type_node
301#define T89_G { STD_C89, NULL, &local_gcall_ptr_node }
302#define T89_T { STD_C89, NULL, &local_tree_type_node }
303#define T89_V { STD_C89, NULL, T_V }
304#define T_W &wchar_type_node
305#define T94_W { STD_C94, "wchar_t", T_W }
306#define TEX_W { STD_EXT, "wchar_t", T_W }
307#define T_WI &wint_type_node
308#define T94_WI { STD_C94, "wint_t", T_WI }
309#define TEX_WI { STD_EXT, "wint_t", T_WI }
310#define T_ST &size_type_node
311#define T99_ST { STD_C99, "size_t", T_ST }
312#define T_SST &signed_size_type_node
313#define T99_SST { STD_C99, "signed size_t", T_SST }
314#define T_PD &ptrdiff_type_node
315#define T99_PD { STD_C99, "ptrdiff_t", T_PD }
316#define T_UPD &unsigned_ptrdiff_type_node
317#define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
318#define T_IM &intmax_type_node
319#define T99_IM { STD_C99, "intmax_t", T_IM }
320#define T_UIM &uintmax_type_node
321#define T99_UIM { STD_C99, "uintmax_t", T_UIM }
322#define T_D32 &dfloat32_type_node
323#define TEX_D32 { STD_EXT, "_Decimal32", T_D32 }
324#define T_D64 &dfloat64_type_node
325#define TEX_D64 { STD_EXT, "_Decimal64", T_D64 }
326#define T_D128 &dfloat128_type_node
327#define TEX_D128 { STD_EXT, "_Decimal128", T_D128 }
328
329/* Structure describing how format attributes such as "printf" are
330 interpreted as "gnu_printf" or "ms_printf" on a particular system.
331 TARGET_OVERRIDES_FORMAT_ATTRIBUTES is used to specify target-specific
332 defaults. */
333struct target_ovr_attr
334{
335 /* The name of the to be copied format attribute. */
336 const char *named_attr_src;
337 /* The name of the to be overridden format attribute. */
338 const char *named_attr_dst;
339};
340
341#endif /* GCC_C_FORMAT_H */
342