From cee6432e9813e9be518150354ae53f3420ff78ad Mon Sep 17 00:00:00 2001 From: ache Date: Wed, 29 Oct 1997 16:14:35 +0000 Subject: Initial import --- contrib/diff/context.c | 468 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 468 insertions(+) create mode 100644 contrib/diff/context.c (limited to 'contrib/diff/context.c') diff --git a/contrib/diff/context.c b/contrib/diff/context.c new file mode 100644 index 0000000..14f950c --- /dev/null +++ b/contrib/diff/context.c @@ -0,0 +1,468 @@ +/* Context-format output routines for GNU DIFF. + Copyright (C) 1988,1989,1991,1992,1993,1994 Free Software Foundation, Inc. + +This file is part of GNU DIFF. + +GNU DIFF is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU DIFF is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU DIFF; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "diff.h" + +static struct change *find_hunk PARAMS((struct change *)); +static void find_function PARAMS((struct file_data const *, int, char const **, size_t *)); +static void mark_ignorable PARAMS((struct change *)); +static void pr_context_hunk PARAMS((struct change *)); +static void pr_unidiff_hunk PARAMS((struct change *)); +static void print_context_label PARAMS ((char const *, struct file_data *, char const *)); +static void print_context_number_range PARAMS((struct file_data const *, int, int)); +static void print_unidiff_number_range PARAMS((struct file_data const *, int, int)); + +/* Last place find_function started searching from. */ +static int find_function_last_search; + +/* The value find_function returned when it started searching there. */ +static int find_function_last_match; + +/* Print a label for a context diff, with a file name and date or a label. */ + +static void +print_context_label (mark, inf, label) + char const *mark; + struct file_data *inf; + char const *label; +{ + if (label) + fprintf (outfile, "%s %s\n", mark, label); + else + { + char const *ct = ctime (&inf->stat.st_mtime); + if (!ct) + ct = "?\n"; + /* See Posix.2 section 4.17.6.1.4 for this format. */ + fprintf (outfile, "%s %s\t%s", mark, inf->name, ct); + } +} + +/* Print a header for a context diff, with the file names and dates. */ + +void +print_context_header (inf, unidiff_flag) + struct file_data inf[]; + int unidiff_flag; +{ + if (unidiff_flag) + { + print_context_label ("---", &inf[0], file_label[0]); + print_context_label ("+++", &inf[1], file_label[1]); + } + else + { + print_context_label ("***", &inf[0], file_label[0]); + print_context_label ("---", &inf[1], file_label[1]); + } +} + +/* Print an edit script in context format. */ + +void +print_context_script (script, unidiff_flag) + struct change *script; + int unidiff_flag; +{ + if (ignore_blank_lines_flag || ignore_regexp_list) + mark_ignorable (script); + else + { + struct change *e; + for (e = script; e; e = e->link) + e->ignore = 0; + } + + find_function_last_search = - files[0].prefix_lines; + find_function_last_match = find_function_last_search - 1; + + if (unidiff_flag) + print_script (script, find_hunk, pr_unidiff_hunk); + else + print_script (script, find_hunk, pr_context_hunk); +} + +/* Print a pair of line numbers with a comma, translated for file FILE. + If the second number is not greater, use the first in place of it. + + Args A and B are internal line numbers. + We print the translated (real) line numbers. */ + +static void +print_context_number_range (file, a, b) + struct file_data const *file; + int a, b; +{ + int trans_a, trans_b; + translate_range (file, a, b, &trans_a, &trans_b); + + /* Note: we can have B < A in the case of a range of no lines. + In this case, we should print the line number before the range, + which is B. */ + if (trans_b > trans_a) + fprintf (outfile, "%d,%d", trans_a, trans_b); + else + fprintf (outfile, "%d", trans_b); +} + +/* Print a portion of an edit script in context format. + HUNK is the beginning of the portion to be printed. + The end is marked by a `link' that has been nulled out. + + Prints out lines from both files, and precedes each + line with the appropriate flag-character. */ + +static void +pr_context_hunk (hunk) + struct change *hunk; +{ + int first0, last0, first1, last1, show_from, show_to, i; + struct change *next; + char const *prefix; + char const *function; + size_t function_length; + FILE *out; + + /* Determine range of line numbers involved in each file. */ + + analyze_hunk (hunk, &first0, &last0, &first1, &last1, &show_from, &show_to); + + if (!show_from && !show_to) + return; + + /* Include a context's width before and after. */ + + i = - files[0].prefix_lines; + first0 = max (first0 - context, i); + first1 = max (first1 - context, i); + last0 = min (last0 + context, files[0].valid_lines - 1); + last1 = min (last1 + context, files[1].valid_lines - 1); + + /* If desired, find the preceding function definition line in file 0. */ + function = 0; + if (function_regexp_list) + find_function (&files[0], first0, &function, &function_length); + + begin_output (); + out = outfile; + + /* If we looked for and found a function this is part of, + include its name in the header of the diff section. */ + fprintf (out, "***************"); + + if (function) + { + fprintf (out, " "); + fwrite (function, 1, min (function_length - 1, 40), out); + } + + fprintf (out, "\n*** "); + print_context_number_range (&files[0], first0, last0); + fprintf (out, " ****\n"); + + if (show_from) + { + next = hunk; + + for (i = first0; i <= last0; i++) + { + /* Skip past changes that apply (in file 0) + only to lines before line I. */ + + while (next && next->line0 + next->deleted <= i) + next = next->link; + + /* Compute the marking for line I. */ + + prefix = " "; + if (next && next->line0 <= i) + /* The change NEXT covers this line. + If lines were inserted here in file 1, this is "changed". + Otherwise it is "deleted". */ + prefix = (next->inserted > 0 ? "!" : "-"); + + print_1_line (prefix, &files[0].linbuf[i]); + } + } + + fprintf (out, "--- "); + print_context_number_range (&files[1], first1, last1); + fprintf (out, " ----\n"); + + if (show_to) + { + next = hunk; + + for (i = first1; i <= last1; i++) + { + /* Skip past changes that apply (in file 1) + only to lines before line I. */ + + while (next && next->line1 + next->inserted <= i) + next = next->link; + + /* Compute the marking for line I. */ + + prefix = " "; + if (next && next->line1 <= i) + /* The change NEXT covers this line. + If lines were deleted here in file 0, this is "changed". + Otherwise it is "inserted". */ + prefix = (next->deleted > 0 ? "!" : "+"); + + print_1_line (prefix, &files[1].linbuf[i]); + } + } +} + +/* Print a pair of line numbers with a comma, translated for file FILE. + If the second number is smaller, use the first in place of it. + If the numbers are equal, print just one number. + + Args A and B are internal line numbers. + We print the translated (real) line numbers. */ + +static void +print_unidiff_number_range (file, a, b) + struct file_data const *file; + int a, b; +{ + int trans_a, trans_b; + translate_range (file, a, b, &trans_a, &trans_b); + + /* Note: we can have B < A in the case of a range of no lines. + In this case, we should print the line number before the range, + which is B. */ + if (trans_b <= trans_a) + fprintf (outfile, trans_b == trans_a ? "%d" : "%d,0", trans_b); + else + fprintf (outfile, "%d,%d", trans_a, trans_b - trans_a + 1); +} + +/* Print a portion of an edit script in unidiff format. + HUNK is the beginning of the portion to be printed. + The end is marked by a `link' that has been nulled out. + + Prints out lines from both files, and precedes each + line with the appropriate flag-character. */ + +static void +pr_unidiff_hunk (hunk) + struct change *hunk; +{ + int first0, last0, first1, last1, show_from, show_to, i, j, k; + struct change *next; + char const *function; + size_t function_length; + FILE *out; + + /* Determine range of line numbers involved in each file. */ + + analyze_hunk (hunk, &first0, &last0, &first1, &last1, &show_from, &show_to); + + if (!show_from && !show_to) + return; + + /* Include a context's width before and after. */ + + i = - files[0].prefix_lines; + first0 = max (first0 - context, i); + first1 = max (first1 - context, i); + last0 = min (last0 + context, files[0].valid_lines - 1); + last1 = min (last1 + context, files[1].valid_lines - 1); + + /* If desired, find the preceding function definition line in file 0. */ + function = 0; + if (function_regexp_list) + find_function (&files[0], first0, &function, &function_length); + + begin_output (); + out = outfile; + + fprintf (out, "@@ -"); + print_unidiff_number_range (&files[0], first0, last0); + fprintf (out, " +"); + print_unidiff_number_range (&files[1], first1, last1); + fprintf (out, " @@"); + + /* If we looked for and found a function this is part of, + include its name in the header of the diff section. */ + + if (function) + { + putc (' ', out); + fwrite (function, 1, min (function_length - 1, 40), out); + } + putc ('\n', out); + + next = hunk; + i = first0; + j = first1; + + while (i <= last0 || j <= last1) + { + + /* If the line isn't a difference, output the context from file 0. */ + + if (!next || i < next->line0) + { + putc (tab_align_flag ? '\t' : ' ', out); + print_1_line (0, &files[0].linbuf[i++]); + j++; + } + else + { + /* For each difference, first output the deleted part. */ + + k = next->deleted; + while (k--) + { + putc ('-', out); + if (tab_align_flag) + putc ('\t', out); + print_1_line (0, &files[0].linbuf[i++]); + } + + /* Then output the inserted part. */ + + k = next->inserted; + while (k--) + { + putc ('+', out); + if (tab_align_flag) + putc ('\t', out); + print_1_line (0, &files[1].linbuf[j++]); + } + + /* We're done with this hunk, so on to the next! */ + + next = next->link; + } + } +} + +/* Scan a (forward-ordered) edit script for the first place that more than + 2*CONTEXT unchanged lines appear, and return a pointer + to the `struct change' for the last change before those lines. */ + +static struct change * +find_hunk (start) + struct change *start; +{ + struct change *prev; + int top0, top1; + int thresh; + + do + { + /* Compute number of first line in each file beyond this changed. */ + top0 = start->line0 + start->deleted; + top1 = start->line1 + start->inserted; + prev = start; + start = start->link; + /* Threshold distance is 2*CONTEXT between two non-ignorable changes, + but only CONTEXT if one is ignorable. */ + thresh = ((prev->ignore || (start && start->ignore)) + ? context + : 2 * context + 1); + /* It is not supposed to matter which file we check in the end-test. + If it would matter, crash. */ + if (start && start->line0 - top0 != start->line1 - top1) + abort (); + } while (start + /* Keep going if less than THRESH lines + elapse before the affected line. */ + && start->line0 < top0 + thresh); + + return prev; +} + +/* Set the `ignore' flag properly in each change in SCRIPT. + It should be 1 if all the lines inserted or deleted in that change + are ignorable lines. */ + +static void +mark_ignorable (script) + struct change *script; +{ + while (script) + { + struct change *next = script->link; + int first0, last0, first1, last1, deletes, inserts; + + /* Turn this change into a hunk: detach it from the others. */ + script->link = 0; + + /* Determine whether this change is ignorable. */ + analyze_hunk (script, &first0, &last0, &first1, &last1, &deletes, &inserts); + /* Reconnect the chain as before. */ + script->link = next; + + /* If the change is ignorable, mark it. */ + script->ignore = (!deletes && !inserts); + + /* Advance to the following change. */ + script = next; + } +} + +/* Find the last function-header line in FILE prior to line number LINENUM. + This is a line containing a match for the regexp in `function_regexp'. + Store the address of the line text into LINEP and the length of the + line into LENP. + Do not store anything if no function-header is found. */ + +static void +find_function (file, linenum, linep, lenp) + struct file_data const *file; + int linenum; + char const **linep; + size_t *lenp; +{ + int i = linenum; + int last = find_function_last_search; + find_function_last_search = i; + + while (--i >= last) + { + /* See if this line is what we want. */ + struct regexp_list *r; + char const *line = file->linbuf[i]; + size_t len = file->linbuf[i + 1] - line; + + for (r = function_regexp_list; r; r = r->next) + if (0 <= re_search (&r->buf, line, len, 0, len, 0)) + { + *linep = line; + *lenp = len; + find_function_last_match = i; + return; + } + } + /* If we search back to where we started searching the previous time, + find the line we found last time. */ + if (find_function_last_match >= - file->prefix_lines) + { + i = find_function_last_match; + *linep = file->linbuf[i]; + *lenp = file->linbuf[i + 1] - *linep; + return; + } + return; +} -- cgit v1.1