463 lines
13 KiB
C
463 lines
13 KiB
C
/* Context-format output routines for GNU DIFF.
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Copyright (C) 1988,1989,1991,1992,1993,1994,1998 Free Software Foundation, Inc.
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This file is part of GNU DIFF.
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GNU DIFF is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU DIFF is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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*/
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#include "diff.h"
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static struct change *find_hunk PARAMS((struct change *));
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static void find_function PARAMS((struct file_data const *, int, char const **, size_t *));
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static void mark_ignorable PARAMS((struct change *));
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static void pr_context_hunk PARAMS((struct change *));
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static void pr_unidiff_hunk PARAMS((struct change *));
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static void print_context_label PARAMS ((char const *, struct file_data *, char const *));
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static void print_context_number_range PARAMS((struct file_data const *, int, int));
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static void print_unidiff_number_range PARAMS((struct file_data const *, int, int));
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/* Last place find_function started searching from. */
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static int find_function_last_search;
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/* The value find_function returned when it started searching there. */
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static int find_function_last_match;
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/* Print a label for a context diff, with a file name and date or a label. */
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static void
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print_context_label (mark, inf, label)
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char const *mark;
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struct file_data *inf;
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char const *label;
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{
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if (label)
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printf_output ("%s %s\n", mark, label);
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else
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{
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char const *ct = ctime (&inf->stat.st_mtime);
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if (!ct)
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ct = "?\n";
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/* See Posix.2 section 4.17.6.1.4 for this format. */
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printf_output ("%s %s\t%s", mark, inf->name, ct);
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}
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}
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/* Print a header for a context diff, with the file names and dates. */
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void
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print_context_header (inf, unidiff_flag)
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struct file_data inf[];
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int unidiff_flag;
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{
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if (unidiff_flag)
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{
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print_context_label ("---", &inf[0], file_label[0]);
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print_context_label ("+++", &inf[1], file_label[1]);
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}
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else
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{
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print_context_label ("***", &inf[0], file_label[0]);
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print_context_label ("---", &inf[1], file_label[1]);
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}
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}
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/* Print an edit script in context format. */
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void
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print_context_script (script, unidiff_flag)
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struct change *script;
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int unidiff_flag;
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{
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if (ignore_blank_lines_flag || ignore_regexp_list)
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mark_ignorable (script);
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else
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{
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struct change *e;
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for (e = script; e; e = e->link)
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e->ignore = 0;
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}
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find_function_last_search = - files[0].prefix_lines;
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find_function_last_match = find_function_last_search - 1;
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if (unidiff_flag)
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print_script (script, find_hunk, pr_unidiff_hunk);
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else
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print_script (script, find_hunk, pr_context_hunk);
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}
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/* Print a pair of line numbers with a comma, translated for file FILE.
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If the second number is not greater, use the first in place of it.
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Args A and B are internal line numbers.
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We print the translated (real) line numbers. */
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static void
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print_context_number_range (file, a, b)
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struct file_data const *file;
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int a, b;
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{
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int trans_a, trans_b;
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translate_range (file, a, b, &trans_a, &trans_b);
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/* Note: we can have B < A in the case of a range of no lines.
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In this case, we should print the line number before the range,
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which is B. */
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if (trans_b > trans_a)
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printf_output ("%d,%d", trans_a, trans_b);
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else
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printf_output ("%d", trans_b);
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}
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/* Print a portion of an edit script in context format.
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HUNK is the beginning of the portion to be printed.
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The end is marked by a `link' that has been nulled out.
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Prints out lines from both files, and precedes each
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line with the appropriate flag-character. */
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static void
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pr_context_hunk (hunk)
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struct change *hunk;
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{
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int first0, last0, first1, last1, show_from, show_to, i;
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struct change *next;
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char const *prefix;
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char const *function;
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size_t function_length;
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/* Determine range of line numbers involved in each file. */
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analyze_hunk (hunk, &first0, &last0, &first1, &last1, &show_from, &show_to);
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if (!show_from && !show_to)
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return;
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/* Include a context's width before and after. */
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i = - files[0].prefix_lines;
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first0 = max (first0 - context, i);
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first1 = max (first1 - context, i);
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last0 = min (last0 + context, files[0].valid_lines - 1);
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last1 = min (last1 + context, files[1].valid_lines - 1);
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/* If desired, find the preceding function definition line in file 0. */
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function = 0;
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if (function_regexp_list)
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find_function (&files[0], first0, &function, &function_length);
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begin_output ();
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/* If we looked for and found a function this is part of,
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include its name in the header of the diff section. */
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printf_output ("***************");
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if (function)
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{
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printf_output (" ");
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write_output (function, min (function_length - 1, 40));
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}
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printf_output ("\n*** ");
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print_context_number_range (&files[0], first0, last0);
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printf_output (" ****\n");
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if (show_from)
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{
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next = hunk;
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for (i = first0; i <= last0; i++)
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{
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/* Skip past changes that apply (in file 0)
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only to lines before line I. */
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while (next && next->line0 + next->deleted <= i)
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next = next->link;
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/* Compute the marking for line I. */
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prefix = " ";
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if (next && next->line0 <= i)
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/* The change NEXT covers this line.
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If lines were inserted here in file 1, this is "changed".
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Otherwise it is "deleted". */
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prefix = (next->inserted > 0 ? "!" : "-");
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print_1_line (prefix, &files[0].linbuf[i]);
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}
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}
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printf_output ("--- ");
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print_context_number_range (&files[1], first1, last1);
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printf_output (" ----\n");
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if (show_to)
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{
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next = hunk;
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for (i = first1; i <= last1; i++)
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{
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/* Skip past changes that apply (in file 1)
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only to lines before line I. */
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while (next && next->line1 + next->inserted <= i)
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next = next->link;
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/* Compute the marking for line I. */
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prefix = " ";
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if (next && next->line1 <= i)
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/* The change NEXT covers this line.
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If lines were deleted here in file 0, this is "changed".
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Otherwise it is "inserted". */
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prefix = (next->deleted > 0 ? "!" : "+");
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print_1_line (prefix, &files[1].linbuf[i]);
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}
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}
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}
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/* Print a pair of line numbers with a comma, translated for file FILE.
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If the second number is smaller, use the first in place of it.
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If the numbers are equal, print just one number.
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Args A and B are internal line numbers.
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We print the translated (real) line numbers. */
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static void
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print_unidiff_number_range (file, a, b)
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struct file_data const *file;
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int a, b;
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{
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int trans_a, trans_b;
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translate_range (file, a, b, &trans_a, &trans_b);
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/* Note: we can have B < A in the case of a range of no lines.
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In this case, we should print the line number before the range,
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which is B. */
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if (trans_b <= trans_a)
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printf_output (trans_b == trans_a ? "%d" : "%d,0", trans_b);
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else
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printf_output ("%d,%d", trans_a, trans_b - trans_a + 1);
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}
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/* Print a portion of an edit script in unidiff format.
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HUNK is the beginning of the portion to be printed.
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The end is marked by a `link' that has been nulled out.
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Prints out lines from both files, and precedes each
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line with the appropriate flag-character. */
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static void
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pr_unidiff_hunk (hunk)
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struct change *hunk;
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{
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int first0, last0, first1, last1, show_from, show_to, i, j, k;
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struct change *next;
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char const *function;
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size_t function_length;
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/* Determine range of line numbers involved in each file. */
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analyze_hunk (hunk, &first0, &last0, &first1, &last1, &show_from, &show_to);
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if (!show_from && !show_to)
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return;
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/* Include a context's width before and after. */
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i = - files[0].prefix_lines;
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first0 = max (first0 - context, i);
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first1 = max (first1 - context, i);
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last0 = min (last0 + context, files[0].valid_lines - 1);
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last1 = min (last1 + context, files[1].valid_lines - 1);
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/* If desired, find the preceding function definition line in file 0. */
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function = 0;
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if (function_regexp_list)
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find_function (&files[0], first0, &function, &function_length);
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begin_output ();
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printf_output ("@@ -");
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print_unidiff_number_range (&files[0], first0, last0);
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printf_output (" +");
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print_unidiff_number_range (&files[1], first1, last1);
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printf_output (" @@");
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/* If we looked for and found a function this is part of,
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include its name in the header of the diff section. */
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if (function)
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{
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write_output (" ", 1);
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write_output (function, min (function_length - 1, 40));
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}
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write_output ("\n", 1);
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next = hunk;
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i = first0;
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j = first1;
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while (i <= last0 || j <= last1)
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{
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/* If the line isn't a difference, output the context from file 0. */
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if (!next || i < next->line0)
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{
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write_output (tab_align_flag ? "\t" : " ", 1);
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print_1_line (0, &files[0].linbuf[i++]);
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j++;
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}
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else
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{
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/* For each difference, first output the deleted part. */
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k = next->deleted;
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while (k--)
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{
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write_output ("-", 1);
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if (tab_align_flag)
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write_output ("\t", 1);
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print_1_line (0, &files[0].linbuf[i++]);
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}
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/* Then output the inserted part. */
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k = next->inserted;
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while (k--)
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{
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write_output ("+", 1);
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if (tab_align_flag)
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write_output ("\t", 1);
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print_1_line (0, &files[1].linbuf[j++]);
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}
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/* We're done with this hunk, so on to the next! */
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next = next->link;
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}
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}
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}
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/* Scan a (forward-ordered) edit script for the first place that more than
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2*CONTEXT unchanged lines appear, and return a pointer
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to the `struct change' for the last change before those lines. */
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static struct change *
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find_hunk (start)
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struct change *start;
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{
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struct change *prev;
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int top0, top1;
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int thresh;
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do
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{
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/* Compute number of first line in each file beyond this changed. */
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top0 = start->line0 + start->deleted;
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top1 = start->line1 + start->inserted;
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prev = start;
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start = start->link;
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/* Threshold distance is 2*CONTEXT between two non-ignorable changes,
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but only CONTEXT if one is ignorable. */
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thresh = ((prev->ignore || (start && start->ignore))
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? context
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: 2 * context + 1);
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/* It is not supposed to matter which file we check in the end-test.
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If it would matter, crash. */
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if (start && start->line0 - top0 != start->line1 - top1)
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abort ();
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} while (start
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/* Keep going if less than THRESH lines
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elapse before the affected line. */
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&& start->line0 < top0 + thresh);
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return prev;
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}
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/* Set the `ignore' flag properly in each change in SCRIPT.
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It should be 1 if all the lines inserted or deleted in that change
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are ignorable lines. */
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static void
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mark_ignorable (script)
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struct change *script;
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{
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while (script)
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{
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struct change *next = script->link;
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int first0, last0, first1, last1, deletes, inserts;
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/* Turn this change into a hunk: detach it from the others. */
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script->link = 0;
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/* Determine whether this change is ignorable. */
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analyze_hunk (script, &first0, &last0, &first1, &last1, &deletes, &inserts);
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/* Reconnect the chain as before. */
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script->link = next;
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/* If the change is ignorable, mark it. */
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script->ignore = (!deletes && !inserts);
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/* Advance to the following change. */
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script = next;
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}
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}
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/* Find the last function-header line in FILE prior to line number LINENUM.
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This is a line containing a match for the regexp in `function_regexp'.
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Store the address of the line text into LINEP and the length of the
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line into LENP.
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Do not store anything if no function-header is found. */
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static void
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find_function (file, linenum, linep, lenp)
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struct file_data const *file;
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int linenum;
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char const **linep;
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size_t *lenp;
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{
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int i = linenum;
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int last = find_function_last_search;
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find_function_last_search = i;
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while (--i >= last)
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{
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/* See if this line is what we want. */
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struct regexp_list *r;
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char const *line = file->linbuf[i];
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size_t len = file->linbuf[i + 1] - line;
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for (r = function_regexp_list; r; r = r->next)
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if (0 <= re_search (&r->buf, line, len, 0, len, 0))
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{
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*linep = line;
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*lenp = len;
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find_function_last_match = i;
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return;
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}
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}
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/* If we search back to where we started searching the previous time,
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find the line we found last time. */
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if (find_function_last_match >= - file->prefix_lines)
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{
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i = find_function_last_match;
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*linep = file->linbuf[i];
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*lenp = file->linbuf[i + 1] - *linep;
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return;
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}
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return;
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}
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