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1 : : /* Source locations within string literals.
2 : : Copyright (C) 2016-2025 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 : : #include "diagnostic-highlight-colors.h"
31 : :
32 : : const char *const
33 : : format_string_diagnostic_t::highlight_color_format_string
34 : : = highlight_colors::expected;
35 : :
36 : : const char *const
37 : : format_string_diagnostic_t::highlight_color_param
38 : : = highlight_colors::actual;
39 : :
40 : : /* format_string_diagnostic_t's ctor, giving information for use by
41 : : the emit_warning* member functions, as follows:
42 : :
43 : : They attempt to obtain precise location information within a string
44 : : literal from FMT_LOC.
45 : :
46 : : Case 1: if substring location is available, and is within the range of
47 : : the format string itself, the primary location of the
48 : : diagnostic is the substring range obtained from FMT_LOC, with the
49 : : caret at the *end* of the substring range.
50 : :
51 : : For example:
52 : :
53 : : test.c:90:10: warning: problem with '%i' here [-Wformat=]
54 : : printf ("hello %i", msg);
55 : : ~^
56 : :
57 : : Case 2: if the substring location is available, but is not within
58 : : the range of the format string, the primary location is that of the
59 : : format string, and a note is emitted showing the substring location.
60 : :
61 : : For example:
62 : : test.c:90:10: warning: problem with '%i' here [-Wformat=]
63 : : printf("hello " INT_FMT " world", msg);
64 : : ^~~~~~~~~~~~~~~~~~~~~~~~~
65 : : test.c:19: note: format string is defined here
66 : : #define INT_FMT "%i"
67 : : ~^
68 : :
69 : : Case 3: if precise substring information is unavailable, the primary
70 : : location is that of the whole string passed to FMT_LOC's constructor.
71 : : For example:
72 : :
73 : : test.c:90:10: warning: problem with '%i' here [-Wformat=]
74 : : printf(fmt, msg);
75 : : ^~~
76 : :
77 : : For each of cases 1-3, if param_loc is not UNKNOWN_LOCATION, then it is used
78 : : as a secondary range within the warning. For example, here it
79 : : is used with case 1:
80 : :
81 : : test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
82 : : printf ("foo %s bar", long_i + long_j);
83 : : ~^ ~~~~~~~~~~~~~~~
84 : :
85 : : and here with case 2:
86 : :
87 : : test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
88 : : printf ("foo " STR_FMT " bar", long_i + long_j);
89 : : ^~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~
90 : : test.c:89:16: note: format string is defined here
91 : : #define STR_FMT "%s"
92 : : ~^
93 : :
94 : : and with case 3:
95 : :
96 : : test.c:90:10: warning: '%i' here, but arg 2 is "const char *' [-Wformat=]
97 : : printf(fmt, msg);
98 : : ^~~ ~~~
99 : :
100 : : If non-NULL, then FMT_LABEL will be used to label the location within the
101 : : string for cases 1 and 2; if non-NULL, then PARAM_LABEL will be used to label
102 : : the parameter. For example with case 1:
103 : :
104 : : test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
105 : : printf ("foo %s bar", long_i + long_j);
106 : : ~^ ~~~~~~~~~~~~~~~
107 : : |
108 : : int
109 : :
110 : : and with case 2:
111 : :
112 : : test.c:90:10: warning: problem with '%i' here [-Wformat=]
113 : : printf("hello " INT_FMT " world", msg);
114 : : ^~~~~~~~~~~~~~~~~~~~~~~~~
115 : : test.c:19: note: format string is defined here
116 : : #define INT_FMT "%i"
117 : : ~^
118 : : |
119 : : int
120 : :
121 : : If CORRECTED_SUBSTRING is non-NULL, use it for cases 1 and 2 to provide
122 : : a fix-it hint, suggesting that it should replace the text within the
123 : : substring range. For example:
124 : :
125 : : test.c:90:10: warning: problem with '%i' here [-Wformat=]
126 : : printf ("hello %i", msg);
127 : : ~^
128 : : %s
129 : :
130 : : */
131 : :
132 : 10672 : format_string_diagnostic_t::
133 : : format_string_diagnostic_t (const substring_loc &fmt_loc,
134 : : const range_label *fmt_label,
135 : : location_t param_loc,
136 : : const range_label *param_label,
137 : 10672 : const char *corrected_substring)
138 : 10672 : : m_fmt_loc (fmt_loc),
139 : 10672 : m_fmt_label (fmt_label),
140 : 10672 : m_param_loc (param_loc),
141 : 10672 : m_param_label (param_label),
142 : 10672 : m_corrected_substring (corrected_substring)
143 : : {
144 : 10672 : }
145 : :
146 : : /* Emit a warning governed by option OPTION_ID, using SINGULAR_GMSGID as the
147 : : format string (or if PLURAL_GMSGID is different from SINGULAR_GMSGID,
148 : : using SINGULAR_GMSGID, PLURAL_GMSGID and N as arguments to ngettext)
149 : : and AP as its arguments.
150 : :
151 : : Return true if a warning was emitted, false otherwise. */
152 : :
153 : : bool
154 : 10672 : format_string_diagnostic_t::emit_warning_n_va (diagnostic_option_id option_id,
155 : : unsigned HOST_WIDE_INT n,
156 : : const char *singular_gmsgid,
157 : : const char *plural_gmsgid,
158 : : va_list *ap) const
159 : : {
160 : 10672 : bool substring_within_range = false;
161 : 10672 : location_t primary_loc;
162 : 10672 : location_t fmt_substring_loc = UNKNOWN_LOCATION;
163 : 10672 : source_range fmt_loc_range
164 : 10672 : = get_range_from_loc (line_table, m_fmt_loc.get_fmt_string_loc ());
165 : 10672 : const char *err = m_fmt_loc.get_location (&fmt_substring_loc);
166 : 10672 : source_range fmt_substring_range
167 : 10672 : = get_range_from_loc (line_table, fmt_substring_loc);
168 : 10672 : if (err)
169 : : /* Case 3: unable to get substring location. */
170 : 3182 : primary_loc = m_fmt_loc.get_fmt_string_loc ();
171 : : else
172 : : {
173 : 7490 : if (fmt_substring_range.m_start >= fmt_loc_range.m_start
174 : 5878 : && fmt_substring_range.m_start <= fmt_loc_range.m_finish
175 : 5728 : && fmt_substring_range.m_finish >= fmt_loc_range.m_start
176 : 5718 : && fmt_substring_range.m_finish <= fmt_loc_range.m_finish)
177 : : /* Case 1. */
178 : : {
179 : 5716 : substring_within_range = true;
180 : 5716 : primary_loc = fmt_substring_loc;
181 : : }
182 : : else
183 : : /* Case 2. */
184 : : {
185 : 1774 : substring_within_range = false;
186 : 1774 : primary_loc = m_fmt_loc.get_fmt_string_loc ();
187 : : }
188 : : }
189 : :
190 : : /* Only use fmt_label in the initial warning for case 1. */
191 : 10672 : const range_label *primary_label = NULL;
192 : 4956 : if (substring_within_range)
193 : 5716 : primary_label = m_fmt_label;
194 : :
195 : 10672 : auto_diagnostic_group d;
196 : 10672 : gcc_rich_location richloc (primary_loc, primary_label,
197 : 10672 : highlight_color_format_string);
198 : :
199 : 10672 : if (m_param_loc != UNKNOWN_LOCATION)
200 : 1534 : richloc.add_range (m_param_loc, SHOW_RANGE_WITHOUT_CARET, m_param_label,
201 : : highlight_color_param);
202 : :
203 : 10672 : if (!err && m_corrected_substring && substring_within_range)
204 : 899 : richloc.add_fixit_replace (fmt_substring_range, m_corrected_substring);
205 : :
206 : 10672 : diagnostic_info diagnostic;
207 : 10672 : if (singular_gmsgid != plural_gmsgid)
208 : : {
209 : 543 : unsigned long gtn;
210 : :
211 : 543 : if (sizeof n <= sizeof gtn)
212 : 543 : gtn = n;
213 : : else
214 : : /* Use the largest number ngettext can handle, otherwise
215 : : preserve the six least significant decimal digits for
216 : : languages where the plural form depends on them. */
217 : : gtn = n <= ULONG_MAX ? n : n % 1000000LU + 1000000LU;
218 : :
219 : 543 : const char *text = ngettext (singular_gmsgid, plural_gmsgid, gtn);
220 : 543 : diagnostic_set_info_translated (&diagnostic, text, ap, &richloc,
221 : : DK_WARNING);
222 : : }
223 : : else
224 : 10129 : diagnostic_set_info (&diagnostic, singular_gmsgid, ap, &richloc,
225 : : DK_WARNING);
226 : 10672 : diagnostic.option_id = option_id;
227 : 10672 : bool warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
228 : :
229 : 10672 : if (!err && fmt_substring_loc && !substring_within_range)
230 : : /* Case 2. */
231 : 1774 : if (warned)
232 : : {
233 : : /* Use fmt_label in the note for case 2. */
234 : 51 : rich_location substring_richloc
235 : : (line_table, fmt_substring_loc,
236 : 51 : m_fmt_label,
237 : 51 : highlight_color_format_string);
238 : 51 : if (m_corrected_substring)
239 : 25 : substring_richloc.add_fixit_replace (fmt_substring_range,
240 : : m_corrected_substring);
241 : 51 : inform (&substring_richloc,
242 : : "format string is defined here");
243 : 51 : }
244 : :
245 : 10672 : return warned;
246 : 10672 : }
247 : :
248 : : /* Singular-only version of the above. */
249 : :
250 : : bool
251 : 10129 : format_string_diagnostic_t::emit_warning_va (diagnostic_option_id option_id,
252 : : const char *gmsgid,
253 : : va_list *ap) const
254 : : {
255 : 10129 : return emit_warning_n_va (option_id, 0, gmsgid, gmsgid, ap);
256 : : }
257 : :
258 : : /* Variadic version of the above (singular only). */
259 : :
260 : : bool
261 : 1161 : format_string_diagnostic_t::emit_warning (diagnostic_option_id option_id,
262 : : const char *gmsgid,
263 : : ...) const
264 : : {
265 : 1161 : va_list ap;
266 : 1161 : va_start (ap, gmsgid);
267 : 1161 : bool warned = emit_warning_va (option_id, gmsgid, &ap);
268 : 1161 : va_end (ap);
269 : :
270 : 1161 : return warned;
271 : : }
272 : :
273 : : /* Variadic version of the above (singular vs plural). */
274 : :
275 : : bool
276 : 0 : format_string_diagnostic_t::emit_warning_n (diagnostic_option_id option_id,
277 : : unsigned HOST_WIDE_INT n,
278 : : const char *singular_gmsgid,
279 : : const char *plural_gmsgid,
280 : : ...) const
281 : : {
282 : 0 : va_list ap;
283 : 0 : va_start (ap, plural_gmsgid);
284 : 0 : bool warned = emit_warning_n_va (option_id, n, singular_gmsgid, plural_gmsgid,
285 : : &ap);
286 : 0 : va_end (ap);
287 : :
288 : 0 : return warned;
289 : : }
290 : :
291 : : /* Attempt to determine the source location of the substring.
292 : : If successful, return NULL and write the source location to *OUT_LOC.
293 : : Otherwise return an error message. Error messages are intended
294 : : for GCC developers (to help debugging) rather than for end-users. */
295 : :
296 : : const char *
297 : 11761 : substring_loc::get_location (location_t *out_loc) const
298 : : {
299 : 11761 : gcc_assert (out_loc);
300 : 11761 : return lang_hooks.get_substring_location (*this, out_loc);
301 : : }
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