1 /* Context-format output routines for GNU DIFF.
3 Copyright (C) 1988-1989, 1991-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
4 2015-2021 Free Software Foundation, Inc.
6 This file is part of GNU DIFF.
8 This program is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include <stat-time.h>
26 static char const *find_function (char const * const *, lin);
27 static struct change *find_hunk (struct change *);
28 static void mark_ignorable (struct change *);
29 static void pr_context_hunk (struct change *);
30 static void pr_unidiff_hunk (struct change *);
32 /* Last place find_function started searching from. */
33 static lin find_function_last_search;
35 /* The value find_function returned when it started searching there. */
36 static lin find_function_last_match;
38 /* Print a label for a context diff, with a file name and date or a label. */
41 print_context_label (char const *mark,
42 struct file_data *inf,
46 set_color_context (HEADER_CONTEXT);
48 fprintf (outfile, "%s %s", mark, label);
51 char buf[MAX (INT_STRLEN_BOUND (int) + 32,
52 INT_STRLEN_BOUND (time_t) + 11)];
53 struct tm const *tm = localtime (&inf->stat.st_mtime);
54 int nsec = get_stat_mtime_ns (&inf->stat);
55 if (! (tm && nstrftime (buf, sizeof buf, time_format, tm, 0, nsec)))
57 verify (TYPE_IS_INTEGER (time_t));
58 if (LONG_MIN <= TYPE_MINIMUM (time_t)
59 && TYPE_MAXIMUM (time_t) <= LONG_MAX)
61 long int sec = inf->stat.st_mtime;
62 sprintf (buf, "%ld.%.9d", sec, nsec);
64 else if (TYPE_MAXIMUM (time_t) <= INTMAX_MAX)
66 intmax_t sec = inf->stat.st_mtime;
67 sprintf (buf, "%"PRIdMAX".%.9d", sec, nsec);
71 uintmax_t sec = inf->stat.st_mtime;
72 sprintf (buf, "%"PRIuMAX".%.9d", sec, nsec);
75 fprintf (outfile, "%s %s\t%s", mark, name, buf);
77 set_color_context (RESET_CONTEXT);
81 /* Print a header for a context diff, with the file names and dates. */
84 print_context_header (struct file_data inf[], char const *const *names, bool unidiff)
88 print_context_label ("---", &inf[0], names[0], file_label[0]);
89 print_context_label ("+++", &inf[1], names[1], file_label[1]);
93 print_context_label ("***", &inf[0], names[0], file_label[0]);
94 print_context_label ("---", &inf[1], names[1], file_label[1]);
98 /* Print an edit script in context format. */
101 print_context_script (struct change *script, bool unidiff)
103 if (ignore_blank_lines || ignore_regexp.fastmap)
104 mark_ignorable (script);
108 for (e = script; e; e = e->link)
112 find_function_last_search = - files[0].prefix_lines;
113 find_function_last_match = LIN_MAX;
116 print_script (script, find_hunk, pr_unidiff_hunk);
118 print_script (script, find_hunk, pr_context_hunk);
121 /* Print a pair of line numbers with a comma, translated for file FILE.
122 If the second number is not greater, use the first in place of it.
124 Args A and B are internal line numbers.
125 We print the translated (real) line numbers. */
128 print_context_number_range (struct file_data const *file, lin a, lin b)
130 printint trans_a, trans_b;
131 translate_range (file, a, b, &trans_a, &trans_b);
133 /* We can have B <= A in the case of a range of no lines.
134 In this case, we should print the line number before the range,
137 POSIX 1003.1-2001 requires two line numbers separated by a comma
138 even if the line numbers are the same. However, this does not
139 match existing practice and is surely an error in the
142 if (trans_b <= trans_a)
143 fprintf (outfile, "%"pI"d", trans_b);
145 fprintf (outfile, "%"pI"d,%"pI"d", trans_a, trans_b);
148 /* Print FUNCTION in a context header. */
150 print_context_function (FILE *out, char const *function)
154 for (i = 0; c_isspace ((unsigned char) function[i]) && function[i] != '\n'; i++)
156 for (j = i; j < i + 40 && function[j] != '\n'; j++)
158 while (i < j && c_isspace ((unsigned char) function[j - 1]))
160 fwrite (function + i, sizeof (char), j - i, out);
163 /* Print a portion of an edit script in context format.
164 HUNK is the beginning of the portion to be printed.
165 The end is marked by a 'link' that has been nulled out.
167 Prints out lines from both files, and precedes each
168 line with the appropriate flag-character. */
171 pr_context_hunk (struct change *hunk)
173 lin first0, last0, first1, last1, i;
175 char const *function;
178 /* Determine range of line numbers involved in each file. */
180 enum changes changes = analyze_hunk (hunk, &first0, &last0, &first1, &last1);
184 /* Include a context's width before and after. */
186 i = - files[0].prefix_lines;
187 first0 = MAX (first0 - context, i);
188 first1 = MAX (first1 - context, i);
189 if (last0 < files[0].valid_lines - context)
192 last0 = files[0].valid_lines - 1;
193 if (last1 < files[1].valid_lines - context)
196 last1 = files[1].valid_lines - 1;
198 /* If desired, find the preceding function definition line in file 0. */
200 if (function_regexp.fastmap)
201 function = find_function (files[0].linbuf, first0);
206 fputs ("***************", out);
209 print_context_function (out, function);
212 set_color_context (LINE_NUMBER_CONTEXT);
214 print_context_number_range (&files[0], first0, last0);
215 fputs (" ****", out);
216 set_color_context (RESET_CONTEXT);
221 struct change *next = hunk;
223 for (i = first0; i <= last0; i++)
225 set_color_context (DELETE_CONTEXT);
227 /* Skip past changes that apply (in file 0)
228 only to lines before line I. */
230 while (next && next->line0 + next->deleted <= i)
233 /* Compute the marking for line I. */
236 if (next && next->line0 <= i)
238 /* The change NEXT covers this line.
239 If lines were inserted here in file 1, this is "changed".
240 Otherwise it is "deleted". */
241 prefix = (next->inserted > 0 ? "!" : "-");
243 print_1_line_nl (prefix, &files[0].linbuf[i], true);
244 set_color_context (RESET_CONTEXT);
245 if (files[0].linbuf[i + 1][-1] == '\n')
250 set_color_context (LINE_NUMBER_CONTEXT);
252 print_context_number_range (&files[1], first1, last1);
253 fputs (" ----", out);
254 set_color_context (RESET_CONTEXT);
259 struct change *next = hunk;
261 for (i = first1; i <= last1; i++)
263 set_color_context (ADD_CONTEXT);
265 /* Skip past changes that apply (in file 1)
266 only to lines before line I. */
268 while (next && next->line1 + next->inserted <= i)
271 /* Compute the marking for line I. */
274 if (next && next->line1 <= i)
276 /* The change NEXT covers this line.
277 If lines were deleted here in file 0, this is "changed".
278 Otherwise it is "inserted". */
279 prefix = (next->deleted > 0 ? "!" : "+");
281 print_1_line_nl (prefix, &files[1].linbuf[i], true);
282 set_color_context (RESET_CONTEXT);
283 if (files[1].linbuf[i + 1][-1] == '\n')
289 /* Print a pair of line numbers with a comma, translated for file FILE.
290 If the second number is smaller, use the first in place of it.
291 If the numbers are equal, print just one number.
293 Args A and B are internal line numbers.
294 We print the translated (real) line numbers. */
297 print_unidiff_number_range (struct file_data const *file, lin a, lin b)
299 printint trans_a, trans_b;
300 translate_range (file, a, b, &trans_a, &trans_b);
302 /* We can have B < A in the case of a range of no lines.
303 In this case, we print the line number before the range,
304 which is B. It would be more logical to print A, but
305 'patch' expects B in order to detect diffs against empty files. */
306 if (trans_b <= trans_a)
307 fprintf (outfile, trans_b < trans_a ? "%"pI"d,0" : "%"pI"d", trans_b);
309 fprintf (outfile, "%"pI"d,%"pI"d", trans_a, trans_b - trans_a + 1);
312 /* Print a portion of an edit script in unidiff format.
313 HUNK is the beginning of the portion to be printed.
314 The end is marked by a 'link' that has been nulled out.
316 Prints out lines from both files, and precedes each
317 line with the appropriate flag-character. */
320 pr_unidiff_hunk (struct change *hunk)
322 lin first0, last0, first1, last1;
325 char const *function;
328 /* Determine range of line numbers involved in each file. */
330 if (! analyze_hunk (hunk, &first0, &last0, &first1, &last1))
333 /* Include a context's width before and after. */
335 i = - files[0].prefix_lines;
336 first0 = MAX (first0 - context, i);
337 first1 = MAX (first1 - context, i);
338 if (last0 < files[0].valid_lines - context)
341 last0 = files[0].valid_lines - 1;
342 if (last1 < files[1].valid_lines - context)
345 last1 = files[1].valid_lines - 1;
347 /* If desired, find the preceding function definition line in file 0. */
349 if (function_regexp.fastmap)
350 function = find_function (files[0].linbuf, first0);
355 set_color_context (LINE_NUMBER_CONTEXT);
357 print_unidiff_number_range (&files[0], first0, last0);
359 print_unidiff_number_range (&files[1], first1, last1);
361 set_color_context (RESET_CONTEXT);
364 print_context_function (out, function);
372 while (i <= last0 || j <= last1)
375 /* If the line isn't a difference, output the context from file 0. */
377 if (!next || i < next->line0)
379 char const *const *line = &files[0].linbuf[i++];
380 if (! (suppress_blank_empty && **line == '\n'))
381 putc (initial_tab ? '\t' : ' ', out);
382 print_1_line (NULL, line);
387 /* For each difference, first output the deleted part. */
393 char const * const *line = &files[0].linbuf[i++];
394 set_color_context (DELETE_CONTEXT);
396 if (initial_tab && ! (suppress_blank_empty && **line == '\n'))
398 print_1_line_nl (NULL, line, true);
400 set_color_context (RESET_CONTEXT);
402 if (line[1][-1] == '\n')
406 /* Then output the inserted part. */
412 char const * const *line = &files[1].linbuf[j++];
413 set_color_context (ADD_CONTEXT);
415 if (initial_tab && ! (suppress_blank_empty && **line == '\n'))
417 print_1_line_nl (NULL, line, true);
419 set_color_context (RESET_CONTEXT);
421 if (line[1][-1] == '\n')
425 /* We're done with this hunk, so on to the next! */
432 /* Scan a (forward-ordered) edit script for the first place that more than
433 2*CONTEXT unchanged lines appear, and return a pointer
434 to the 'struct change' for the last change before those lines. */
436 static struct change * _GL_ATTRIBUTE_PURE
437 find_hunk (struct change *start)
443 /* Threshold distance is CONTEXT if the second change is ignorable,
444 2 * CONTEXT + 1 otherwise. Integer overflow can't happen, due
446 lin ignorable_threshold = context;
447 lin non_ignorable_threshold = 2 * context + 1;
451 /* Compute number of first line in each file beyond this changed. */
452 top0 = start->line0 + start->deleted;
453 top1 = start->line1 + start->inserted;
456 thresh = (start && start->ignore
457 ? ignorable_threshold
458 : non_ignorable_threshold);
459 /* It is not supposed to matter which file we check in the end-test.
460 If it would matter, crash. */
461 if (start && start->line0 - top0 != start->line1 - top1)
464 /* Keep going if less than THRESH lines
465 elapse before the affected line. */
466 && start->line0 - top0 < thresh);
471 /* Set the 'ignore' flag properly in each change in SCRIPT.
472 It should be 1 if all the lines inserted or deleted in that change
473 are ignorable lines. */
476 mark_ignorable (struct change *script)
480 struct change *next = script->link;
481 lin first0, last0, first1, last1;
483 /* Turn this change into a hunk: detach it from the others. */
486 /* Determine whether this change is ignorable. */
487 script->ignore = ! analyze_hunk (script,
488 &first0, &last0, &first1, &last1);
490 /* Reconnect the chain as before. */
493 /* Advance to the following change. */
498 /* Find the last function-header line in LINBUF prior to line number LINENUM.
499 This is a line containing a match for the regexp in 'function_regexp'.
500 Return the address of the text, or NULL if no function-header is found. */
503 find_function (char const * const *linbuf, lin linenum)
506 lin last = find_function_last_search;
507 find_function_last_search = i;
511 /* See if this line is what we want. */
512 char const *line = linbuf[i];
513 size_t linelen = linbuf[i + 1] - line - 1;
515 /* FIXME: re_search's size args should be size_t, not int. */
516 int len = MIN (linelen, INT_MAX);
518 if (0 <= re_search (&function_regexp, line, len, 0, len, NULL))
520 find_function_last_match = i;
524 /* If we search back to where we started searching the previous time,
525 find the line we found last time. */
526 if (find_function_last_match != LIN_MAX)
527 return linbuf[find_function_last_match];