1 /* Source locations within string literals. 2 Copyright (C) 2016-2022 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 (line_table, m_fmt_loc.get_fmt_string_loc ()); 156 const char *err = m_fmt_loc.get_location (&fmt_substring_loc); 157 source_range fmt_substring_range 158 = get_range_from_loc (line_table, 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 (m_param_loc, SHOW_RANGE_WITHOUT_CARET, m_param_label); 191 192 if (!err && m_corrected_substring && substring_within_range) 193 richloc.add_fixit_replace (fmt_substring_range, 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 (singular_gmsgid, plural_gmsgid, 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 (global_dc, &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 (fmt_substring_range, 227 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, 0, 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); 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); 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
Indexes created Tue Feb 24 01:34:59 UTC 2026