1 | /* Source locations within string literals. |
2 | Copyright (C) 2016-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "intl.h" |
24 | #include "diagnostic.h" |
25 | #include "cpplib.h" |
26 | #include "tree.h" |
27 | #include "langhooks.h" |
28 | #include "substring-locations.h" |
29 | #include "gcc-rich-location.h" |
30 | |
31 | /* format_string_diagnostic_t's ctor, giving information for use by |
32 | the emit_warning* member functions, as follows: |
33 | |
34 | They attempt to obtain precise location information within a string |
35 | literal from FMT_LOC. |
36 | |
37 | Case 1: if substring location is available, and is within the range of |
38 | the format string itself, the primary location of the |
39 | diagnostic is the substring range obtained from FMT_LOC, with the |
40 | caret at the *end* of the substring range. |
41 | |
42 | For example: |
43 | |
44 | test.c:90:10: warning: problem with '%i' here [-Wformat=] |
45 | printf ("hello %i", msg); |
46 | ~^ |
47 | |
48 | Case 2: if the substring location is available, but is not within |
49 | the range of the format string, the primary location is that of the |
50 | format string, and a note is emitted showing the substring location. |
51 | |
52 | For example: |
53 | test.c:90:10: warning: problem with '%i' here [-Wformat=] |
54 | printf("hello " INT_FMT " world", msg); |
55 | ^~~~~~~~~~~~~~~~~~~~~~~~~ |
56 | test.c:19: note: format string is defined here |
57 | #define INT_FMT "%i" |
58 | ~^ |
59 | |
60 | Case 3: if precise substring information is unavailable, the primary |
61 | location is that of the whole string passed to FMT_LOC's constructor. |
62 | For example: |
63 | |
64 | test.c:90:10: warning: problem with '%i' here [-Wformat=] |
65 | printf(fmt, msg); |
66 | ^~~ |
67 | |
68 | For each of cases 1-3, if param_loc is not UNKNOWN_LOCATION, then it is used |
69 | as a secondary range within the warning. For example, here it |
70 | is used with case 1: |
71 | |
72 | test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=] |
73 | printf ("foo %s bar", long_i + long_j); |
74 | ~^ ~~~~~~~~~~~~~~~ |
75 | |
76 | and here with case 2: |
77 | |
78 | test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=] |
79 | printf ("foo " STR_FMT " bar", long_i + long_j); |
80 | ^~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~ |
81 | test.c:89:16: note: format string is defined here |
82 | #define STR_FMT "%s" |
83 | ~^ |
84 | |
85 | and with case 3: |
86 | |
87 | test.c:90:10: warning: '%i' here, but arg 2 is "const char *' [-Wformat=] |
88 | printf(fmt, msg); |
89 | ^~~ ~~~ |
90 | |
91 | If non-NULL, then FMT_LABEL will be used to label the location within the |
92 | string for cases 1 and 2; if non-NULL, then PARAM_LABEL will be used to label |
93 | the parameter. For example with case 1: |
94 | |
95 | test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=] |
96 | printf ("foo %s bar", long_i + long_j); |
97 | ~^ ~~~~~~~~~~~~~~~ |
98 | | |
99 | int |
100 | |
101 | and with case 2: |
102 | |
103 | test.c:90:10: warning: problem with '%i' here [-Wformat=] |
104 | printf("hello " INT_FMT " world", msg); |
105 | ^~~~~~~~~~~~~~~~~~~~~~~~~ |
106 | test.c:19: note: format string is defined here |
107 | #define INT_FMT "%i" |
108 | ~^ |
109 | | |
110 | int |
111 | |
112 | If CORRECTED_SUBSTRING is non-NULL, use it for cases 1 and 2 to provide |
113 | a fix-it hint, suggesting that it should replace the text within the |
114 | substring range. For example: |
115 | |
116 | test.c:90:10: warning: problem with '%i' here [-Wformat=] |
117 | printf ("hello %i", msg); |
118 | ~^ |
119 | %s |
120 | |
121 | */ |
122 | |
123 | format_string_diagnostic_t:: |
124 | format_string_diagnostic_t (const substring_loc &fmt_loc, |
125 | const range_label *fmt_label, |
126 | location_t param_loc, |
127 | const range_label *param_label, |
128 | const char *corrected_substring) |
129 | : m_fmt_loc (fmt_loc), |
130 | m_fmt_label (fmt_label), |
131 | m_param_loc (param_loc), |
132 | m_param_label (param_label), |
133 | m_corrected_substring (corrected_substring) |
134 | { |
135 | } |
136 | |
137 | /* Emit a warning governed by option OPT, using SINGULAR_GMSGID as the |
138 | format string (or if PLURAL_GMSGID is different from SINGULAR_GMSGID, |
139 | using SINGULAR_GMSGID, PLURAL_GMSGID and N as arguments to ngettext) |
140 | and AP as its arguments. |
141 | |
142 | Return true if a warning was emitted, false otherwise. */ |
143 | |
144 | bool |
145 | format_string_diagnostic_t::emit_warning_n_va (int opt, |
146 | unsigned HOST_WIDE_INT n, |
147 | const char *singular_gmsgid, |
148 | const char *plural_gmsgid, |
149 | va_list *ap) const |
150 | { |
151 | bool substring_within_range = false; |
152 | location_t primary_loc; |
153 | location_t fmt_substring_loc = UNKNOWN_LOCATION; |
154 | source_range fmt_loc_range |
155 | = get_range_from_loc (set: line_table, loc: m_fmt_loc.get_fmt_string_loc ()); |
156 | const char *err = m_fmt_loc.get_location (out_loc: &fmt_substring_loc); |
157 | source_range fmt_substring_range |
158 | = get_range_from_loc (set: line_table, loc: fmt_substring_loc); |
159 | if (err) |
160 | /* Case 3: unable to get substring location. */ |
161 | primary_loc = m_fmt_loc.get_fmt_string_loc (); |
162 | else |
163 | { |
164 | if (fmt_substring_range.m_start >= fmt_loc_range.m_start |
165 | && fmt_substring_range.m_start <= fmt_loc_range.m_finish |
166 | && fmt_substring_range.m_finish >= fmt_loc_range.m_start |
167 | && fmt_substring_range.m_finish <= fmt_loc_range.m_finish) |
168 | /* Case 1. */ |
169 | { |
170 | substring_within_range = true; |
171 | primary_loc = fmt_substring_loc; |
172 | } |
173 | else |
174 | /* Case 2. */ |
175 | { |
176 | substring_within_range = false; |
177 | primary_loc = m_fmt_loc.get_fmt_string_loc (); |
178 | } |
179 | } |
180 | |
181 | /* Only use fmt_label in the initial warning for case 1. */ |
182 | const range_label *primary_label = NULL; |
183 | if (substring_within_range) |
184 | primary_label = m_fmt_label; |
185 | |
186 | auto_diagnostic_group d; |
187 | gcc_rich_location richloc (primary_loc, primary_label); |
188 | |
189 | if (m_param_loc != UNKNOWN_LOCATION) |
190 | richloc.add_range (loc: m_param_loc, range_display_kind: SHOW_RANGE_WITHOUT_CARET, label: m_param_label); |
191 | |
192 | if (!err && m_corrected_substring && substring_within_range) |
193 | richloc.add_fixit_replace (src_range: fmt_substring_range, new_content: m_corrected_substring); |
194 | |
195 | diagnostic_info diagnostic; |
196 | if (singular_gmsgid != plural_gmsgid) |
197 | { |
198 | unsigned long gtn; |
199 | |
200 | if (sizeof n <= sizeof gtn) |
201 | gtn = n; |
202 | else |
203 | /* Use the largest number ngettext can handle, otherwise |
204 | preserve the six least significant decimal digits for |
205 | languages where the plural form depends on them. */ |
206 | gtn = n <= ULONG_MAX ? n : n % 1000000LU + 1000000LU; |
207 | |
208 | const char *text = ngettext (msgid1: singular_gmsgid, msgid2: plural_gmsgid, n: gtn); |
209 | diagnostic_set_info_translated (&diagnostic, text, ap, &richloc, |
210 | DK_WARNING); |
211 | } |
212 | else |
213 | diagnostic_set_info (&diagnostic, singular_gmsgid, ap, &richloc, |
214 | DK_WARNING); |
215 | diagnostic.option_index = opt; |
216 | bool warned = diagnostic_report_diagnostic (context: global_dc, diagnostic: &diagnostic); |
217 | |
218 | if (!err && fmt_substring_loc && !substring_within_range) |
219 | /* Case 2. */ |
220 | if (warned) |
221 | { |
222 | /* Use fmt_label in the note for case 2. */ |
223 | rich_location substring_richloc (line_table, fmt_substring_loc, |
224 | m_fmt_label); |
225 | if (m_corrected_substring) |
226 | substring_richloc.add_fixit_replace (src_range: fmt_substring_range, |
227 | new_content: m_corrected_substring); |
228 | inform (&substring_richloc, |
229 | "format string is defined here" ); |
230 | } |
231 | |
232 | return warned; |
233 | } |
234 | |
235 | /* Singular-only version of the above. */ |
236 | |
237 | bool |
238 | format_string_diagnostic_t::emit_warning_va (int opt, const char *gmsgid, |
239 | va_list *ap) const |
240 | { |
241 | return emit_warning_n_va (opt, n: 0, singular_gmsgid: gmsgid, plural_gmsgid: gmsgid, ap); |
242 | } |
243 | |
244 | /* Variadic version of the above (singular only). */ |
245 | |
246 | bool |
247 | format_string_diagnostic_t::emit_warning (int opt, const char *gmsgid, |
248 | ...) const |
249 | { |
250 | va_list ap; |
251 | va_start (ap, gmsgid); |
252 | bool warned = emit_warning_va (opt, gmsgid, ap: &ap); |
253 | va_end (ap); |
254 | |
255 | return warned; |
256 | } |
257 | |
258 | /* Variadic version of the above (singular vs plural). */ |
259 | |
260 | bool |
261 | format_string_diagnostic_t::emit_warning_n (int opt, unsigned HOST_WIDE_INT n, |
262 | const char *singular_gmsgid, |
263 | const char *plural_gmsgid, |
264 | ...) const |
265 | { |
266 | va_list ap; |
267 | va_start (ap, plural_gmsgid); |
268 | bool warned = emit_warning_n_va (opt, n, singular_gmsgid, plural_gmsgid, |
269 | ap: &ap); |
270 | va_end (ap); |
271 | |
272 | return warned; |
273 | } |
274 | |
275 | /* Attempt to determine the source location of the substring. |
276 | If successful, return NULL and write the source location to *OUT_LOC. |
277 | Otherwise return an error message. Error messages are intended |
278 | for GCC developers (to help debugging) rather than for end-users. */ |
279 | |
280 | const char * |
281 | substring_loc::get_location (location_t *out_loc) const |
282 | { |
283 | gcc_assert (out_loc); |
284 | return lang_hooks.get_substring_location (*this, out_loc); |
285 | } |
286 | |