1/* Source locations within string literals.
2 Copyright (C) 2016-2017 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_SUBSTRING_LOCATIONS_H
21#define GCC_SUBSTRING_LOCATIONS_H
22
23/* The substring_loc class encapsulates information on the source location
24 of a range of characters within a STRING_CST.
25
26 If needed by a diagnostic, the actual location_t of the substring_loc
27 can be calculated by calling its get_location method. This calls a
28 langhook, since this is inherently frontend-specific. For the C family
29 of frontends, it calls back into libcpp to reparse the strings. This
30 gets the location information "on demand", rather than storing the
31 location information in the initial lex for every string. Thus the
32 substring_loc can also be thought of as a deferred call into libcpp,
33 to allow the non-trivial work of reparsing the string to be delayed
34 until we actually need it (to emit a diagnostic for a particular range
35 of characters).
36
37 substring_loc::get_location returns NULL if it succeeds, or an
38 error message if it fails. Error messages are intended for GCC
39 developers (to help debugging) rather than for end-users.
40
41 The easiest way to use a substring_loc is via the format_warning_* APIs,
42 which gracefully handle failure of substring_loc::get_location by using
43 the location of the string as a whole if substring-information is
44 unavailable. */
45
46class substring_loc
47{
48 public:
49 /* Constructor. FMT_STRING_LOC is the location of the string as
50 a whole. STRING_TYPE is the type of the string. It should be an
51 ARRAY_TYPE of INTEGER_TYPE, or a POINTER_TYPE to such an ARRAY_TYPE.
52 CARET_IDX, START_IDX, and END_IDX are offsets from the start
53 of the string data. */
54 substring_loc (location_t fmt_string_loc, tree string_type,
55 int caret_idx, int start_idx, int end_idx)
56 : m_fmt_string_loc (fmt_string_loc), m_string_type (string_type),
57 m_caret_idx (caret_idx), m_start_idx (start_idx), m_end_idx (end_idx) {}
58
59 void set_caret_index (int caret_idx) { m_caret_idx = caret_idx; }
60
61 const char *get_location (location_t *out_loc) const;
62
63 location_t get_fmt_string_loc () const { return m_fmt_string_loc; }
64 tree get_string_type () const { return m_string_type; }
65 int get_caret_idx () const { return m_caret_idx; }
66 int get_start_idx () const { return m_start_idx; }
67 int get_end_idx () const { return m_end_idx; }
68
69 private:
70 location_t m_fmt_string_loc;
71 tree m_string_type;
72 int m_caret_idx;
73 int m_start_idx;
74 int m_end_idx;
75};
76
77/* Functions for emitting a warning about a format string. */
78
79extern bool format_warning_va (const substring_loc &fmt_loc,
80 location_t param_loc,
81 const char *corrected_substring,
82 int opt, const char *gmsgid, va_list *ap)
83 ATTRIBUTE_GCC_DIAG (5,0);
84
85extern bool format_warning_at_substring (const substring_loc &fmt_loc,
86 location_t param_loc,
87 const char *corrected_substring,
88 int opt, const char *gmsgid, ...)
89 ATTRIBUTE_GCC_DIAG (5,0);
90
91/* Implementation detail, for use when implementing
92 LANG_HOOKS_GET_SUBSTRING_LOCATION. */
93
94extern const char *get_source_location_for_substring (cpp_reader *pfile,
95 string_concat_db *concats,
96 location_t strloc,
97 enum cpp_ttype type,
98 int caret_idx,
99 int start_idx, int end_idx,
100 location_t *out_loc);
101
102#endif /* ! GCC_SUBSTRING_LOCATIONS_H */
103