1 /* Shared definitions for GNU DIFF
3 Copyright (C) 1988-1989, 1991-1995, 1998, 2001-2002, 2004, 2009-2010 Free
4 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/>. */
24 #include <unlocked-io.h>
26 /* What kind of changes a hunk contains. */
29 /* No changes: lines common to both files. */
32 /* Deletes only: lines taken from just the first file. */
35 /* Inserts only: lines taken from just the second file. */
38 /* Both deletes and inserts: a hunk containing both old and new lines. */
42 /* Variables for command line options */
52 /* No output style specified. */
55 /* Default output style. */
58 /* Output the differences with lines of context before and after (-c). */
61 /* Output the differences in a unified context diff format (-u). */
64 /* Output the differences as commands suitable for `ed' (-e). */
67 /* Output the diff as a forward ed script (-f). */
70 /* Like -f, but output a count of changed lines in each "command" (-n). */
73 /* Output merged #ifdef'd file (-D). */
76 /* Output sdiff style (-y). */
80 /* True for output styles that are robust,
81 i.e. can handle a file that ends in a non-newline. */
82 #define ROBUST_OUTPUT_STYLE(S) ((S) != OUTPUT_ED && (S) != OUTPUT_FORWARD_ED)
84 XTERN enum output_style output_style;
86 /* Nonzero if output cannot be generated for identical files. */
87 XTERN bool no_diff_means_no_output;
89 /* Number of lines of context to show in each set of diffs.
90 This is zero when context is not to be shown. */
93 /* Consider all files as text files (-a).
94 Don't interpret codes over 0177 as implying a "binary file". */
97 /* Number of lines to keep in identical prefix and suffix. */
98 XTERN lin horizon_lines;
100 /* The significance of white space during comparisons. */
103 /* All white space is significant (the default). */
104 IGNORE_NO_WHITE_SPACE,
106 /* Ignore changes due to tab expansion (-E). */
107 IGNORE_TAB_EXPANSION,
109 /* Ignore changes in horizontal white space (-b). */
112 /* Ignore all horizontal white space (-w). */
114 } ignore_white_space;
116 /* Ignore changes that affect only blank lines (-B). */
117 XTERN bool ignore_blank_lines;
119 /* Files can be compared byte-by-byte, as if they were binary.
120 This depends on various options. */
121 XTERN bool files_can_be_treated_as_binary;
123 /* Ignore differences in case of letters (-i). */
124 XTERN bool ignore_case;
126 /* Ignore differences in case of letters in file names. */
127 XTERN bool ignore_file_name_case;
129 /* File labels for `-c' output headers (--label). */
130 XTERN char *file_label[2];
132 /* Regexp to identify function-header lines (-F). */
133 XTERN struct re_pattern_buffer function_regexp;
135 /* Ignore changes that affect only lines matching this regexp (-I). */
136 XTERN struct re_pattern_buffer ignore_regexp;
138 /* Say only whether files differ, not how (-q). */
141 /* Expand tabs in the output so the text lines up properly
142 despite the characters added to the front of each line (-t). */
143 XTERN bool expand_tabs;
145 /* Number of columns between tab stops. */
146 XTERN size_t tabsize;
148 /* Use a tab in the output, rather than a space, before the text of an
149 input line, so as to keep the proper alignment in the input line
150 without changing the characters in it (-T). */
151 XTERN bool initial_tab;
153 /* Do not output an initial space or tab before the text of an empty line. */
154 XTERN bool suppress_blank_empty;
156 /* Remove trailing carriage returns from input. */
157 XTERN bool strip_trailing_cr;
159 /* In directory comparison, specify file to start with (-S).
160 This is used for resuming an aborted comparison.
161 All file names less than this name are ignored. */
162 XTERN char const *starting_file;
164 /* Pipe each file's output through pr (-l). */
167 /* Line group formats for unchanged, old, new, and changed groups. */
168 XTERN char const *group_format[CHANGED + 1];
170 /* Line formats for unchanged, old, and new lines. */
171 XTERN char const *line_format[NEW + 1];
173 /* If using OUTPUT_SDIFF print extra information to help the sdiff filter. */
174 XTERN bool sdiff_merge_assist;
176 /* Tell OUTPUT_SDIFF to show only the left version of common lines. */
177 XTERN bool left_column;
179 /* Tell OUTPUT_SDIFF to not show common lines. */
180 XTERN bool suppress_common_lines;
182 /* The half line width and column 2 offset for OUTPUT_SDIFF. */
183 XTERN size_t sdiff_half_width;
184 XTERN size_t sdiff_column2_offset;
186 /* String containing all the command options diff received,
187 with spaces between and at the beginning but none at the end.
188 If there were no options given, this string is empty. */
189 XTERN char *switch_string;
191 /* Use heuristics for better speed with large files with a small
192 density of changes. */
193 XTERN bool speed_large_files;
195 /* Patterns that match file names to be excluded. */
196 XTERN struct exclude *excluded;
198 /* Don't discard lines. This makes things slower (sometimes much
199 slower) but will find a guaranteed minimal set of changes. */
202 /* The strftime format to use for time strings. */
203 XTERN char const *time_format;
205 /* The result of comparison is an "edit script": a chain of `struct change'.
206 Each `struct change' represents one place where some lines are deleted
207 and some are inserted.
209 LINE0 and LINE1 are the first affected lines in the two files (origin 0).
210 DELETED is the number of lines deleted here from file 0.
211 INSERTED is the number of lines inserted here in file 1.
213 If DELETED is 0 then LINE0 is the number of the line before
214 which the insertion was done; vice versa for INSERTED and LINE1. */
218 struct change *link; /* Previous or next edit command */
219 lin inserted; /* # lines of file 1 changed here. */
220 lin deleted; /* # lines of file 0 changed here. */
221 lin line0; /* Line number of 1st deleted line. */
222 lin line1; /* Line number of 1st inserted line. */
223 bool ignore; /* Flag used in context.c. */
226 /* Structures that describe the input files. */
228 /* Data on one input file being compared. */
231 int desc; /* File descriptor */
232 char const *name; /* File name */
233 struct stat stat; /* File status */
235 /* Buffer in which text of file is read. */
238 /* Allocated size of buffer, in bytes. Always a multiple of
242 /* Number of valid bytes now in the buffer. */
245 /* Array of pointers to lines in the file. */
248 /* linbuf_base <= buffered_lines <= valid_lines <= alloc_lines.
249 linebuf[linbuf_base ... buffered_lines - 1] are possibly differing.
250 linebuf[linbuf_base ... valid_lines - 1] contain valid data.
251 linebuf[linbuf_base ... alloc_lines - 1] are allocated. */
252 lin linbuf_base, buffered_lines, valid_lines, alloc_lines;
254 /* Pointer to end of prefix of this file to ignore when hashing. */
255 char const *prefix_end;
257 /* Count of lines in the prefix.
258 There are this many lines in the file before linbuf[0]. */
261 /* Pointer to start of suffix of this file to ignore when hashing. */
262 char const *suffix_begin;
264 /* Vector, indexed by line number, containing an equivalence code for
265 each line. It is this vector that is actually compared with that
266 of another file to generate differences. */
269 /* Vector, like the previous one except that
270 the elements for discarded lines have been squeezed out. */
273 /* Vector mapping virtual line numbers (not counting discarded lines)
274 to real ones (counting those lines). Both are origin-0. */
277 /* Total number of nondiscarded lines. */
278 lin nondiscarded_lines;
280 /* Vector, indexed by real origin-0 line number,
281 containing 1 for a line that is an insertion or a deletion.
282 The results of comparison are stored here. */
285 /* 1 if file ends in a line with no final newline. */
286 bool missing_newline;
288 /* 1 if at end of file. */
291 /* 1 more than the maximum equivalence value used for this or its
296 /* The file buffer, considered as an array of bytes rather than
297 as an array of words. */
298 #define FILE_BUFFER(f) ((char *) (f)->buffer)
300 /* Data on two input files being compared. */
304 struct file_data file[2];
305 struct comparison const *parent; /* parent, if a recursive comparison */
308 /* Describe the two files currently being compared. */
310 XTERN struct file_data files[2];
312 /* Stdio stream to output diffs to. */
316 /* Declare various functions. */
319 int diff_2_files (struct comparison *);
322 void print_context_header (struct file_data[], bool);
323 void print_context_script (struct change *, bool);
326 int diff_dirs (struct comparison const *, int (*) (struct comparison const *, char const *, char const *));
329 void print_ed_script (struct change *);
330 void pr_forward_ed_script (struct change *);
333 void print_ifdef_script (struct change *);
336 void file_block_read (struct file_data *, size_t);
337 bool read_files (struct file_data[], bool);
340 void print_normal_script (struct change *);
343 void print_rcs_script (struct change *);
346 void print_sdiff_script (struct change *);
349 extern char const change_letter[4];
350 extern char const pr_program[];
351 char *concat (char const *, char const *, char const *);
352 char *dir_file_pathname (char const *, char const *);
353 bool lines_differ (char const *, char const *);
354 lin translate_line_number (struct file_data const *, lin);
355 struct change *find_change (struct change *);
356 struct change *find_reverse_change (struct change *);
357 void *zalloc (size_t);
358 enum changes analyze_hunk (struct change *, lin *, lin *, lin *, lin *);
359 void begin_output (void);
360 void debug_script (struct change *);
361 void fatal (char const *) __attribute__((noreturn));
362 void finish_output (void);
363 void message (char const *, char const *, char const *);
364 void message5 (char const *, char const *, char const *, char const *, char const *);
365 void output_1_line (char const *, char const *, char const *, char const *);
366 void perror_with_name (char const *);
367 void pfatal_with_name (char const *) __attribute__((noreturn));
368 void print_1_line (char const *, char const * const *);
369 void print_message_queue (void);
370 void print_number_range (char, struct file_data *, lin, lin);
371 void print_script (struct change *, struct change * (*) (struct change *), void (*) (struct change *));
372 void setup_output (char const *, char const *, bool);
373 void translate_range (struct file_data const *, lin, lin, long int *, long int *);