704 lines
16 KiB
C
704 lines
16 KiB
C
/* Support routines for GNU DIFF.
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Copyright (C) 1988, 1989, 1992 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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You should have received a copy of the GNU General Public License
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along with GNU DIFF; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "diff.h"
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/* Use when a system call returns non-zero status.
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TEXT should normally be the file name. */
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void
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perror_with_name (text)
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char *text;
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{
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int e = errno;
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fprintf (stderr, "%s: ", program);
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errno = e;
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perror (text);
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}
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/* Use when a system call returns non-zero status and that is fatal. */
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void
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pfatal_with_name (text)
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char *text;
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{
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int e = errno;
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print_message_queue ();
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fprintf (stderr, "%s: ", program);
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errno = e;
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perror (text);
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exit (2);
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}
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/* Print an error message from the format-string FORMAT
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with args ARG1 and ARG2. */
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void
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error (format, arg, arg1)
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char *format;
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char *arg;
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char *arg1;
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{
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fprintf (stderr, "%s: ", program);
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fprintf (stderr, format, arg, arg1);
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fprintf (stderr, "\n");
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}
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/* Print an error message containing the string TEXT, then exit. */
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void
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fatal (m)
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char *m;
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{
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print_message_queue ();
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error ("%s", m, 0);
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exit (2);
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}
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/* Like printf, except if -l in effect then save the message and print later.
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This is used for things like "binary files differ" and "Only in ...". */
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void
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message (format, arg1, arg2)
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char *format, *arg1, *arg2;
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{
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if (paginate_flag)
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{
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struct msg *new = (struct msg *) xmalloc (sizeof (struct msg));
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if (msg_chain_end == 0)
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msg_chain = msg_chain_end = new;
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else
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{
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msg_chain_end->next = new;
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msg_chain_end = new;
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}
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new->format = format;
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new->arg1 = concat (arg1, "", "");
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new->arg2 = concat (arg2, "", "");
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new->next = 0;
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}
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else
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{
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if (sdiff_help_sdiff)
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putchar (' ');
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printf (format, arg1, arg2);
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}
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}
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/* Output all the messages that were saved up by calls to `message'. */
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void
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print_message_queue ()
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{
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struct msg *m;
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for (m = msg_chain; m; m = m->next)
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printf (m->format, m->arg1, m->arg2);
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}
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/* Call before outputting the results of comparing files NAME0 and NAME1
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to set up OUTFILE, the stdio stream for the output to go to.
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Usually, OUTFILE is just stdout. But when -l was specified
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we fork off a `pr' and make OUTFILE a pipe to it.
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`pr' then outputs to our stdout. */
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static char *current_name0;
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static char *current_name1;
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static int current_depth;
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void
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setup_output (name0, name1, depth)
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char *name0, *name1;
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int depth;
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{
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current_name0 = name0;
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current_name1 = name1;
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current_depth = depth;
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outfile = 0;
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}
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void
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begin_output ()
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{
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char *name;
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if (outfile != 0)
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return;
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/* Construct the header of this piece of diff. */
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name = (char *) xmalloc (strlen (current_name0) + strlen (current_name1)
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+ strlen (switch_string) + 15);
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strcpy (name, "diff");
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strcat (name, switch_string);
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strcat (name, " ");
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strcat (name, current_name0);
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strcat (name, " ");
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strcat (name, current_name1);
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if (paginate_flag)
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{
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int pipes[2];
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int desc;
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/* For a `pr' and make OUTFILE a pipe to it. */
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if (pipe (pipes) < 0)
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pfatal_with_name ("pipe");
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fflush (stdout);
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desc = vfork ();
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if (desc < 0)
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pfatal_with_name ("vfork");
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if (desc == 0)
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{
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close (pipes[1]);
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if (pipes[0] != fileno (stdin))
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{
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if (dup2 (pipes[0], fileno (stdin)) < 0)
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pfatal_with_name ("dup2");
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close (pipes[0]);
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}
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if (execl (PR_FILE_NAME, PR_FILE_NAME, "-f", "-h", name, 0) < 0)
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pfatal_with_name (PR_FILE_NAME);
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}
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else
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{
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close (pipes[0]);
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outfile = fdopen (pipes[1], "w");
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}
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}
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else
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{
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/* If -l was not specified, output the diff straight to `stdout'. */
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outfile = stdout;
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/* If handling multiple files (because scanning a directory),
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print which files the following output is about. */
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if (current_depth > 0)
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printf ("%s\n", name);
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}
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free (name);
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/* A special header is needed at the beginning of context output. */
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switch (output_style)
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{
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case OUTPUT_CONTEXT:
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print_context_header (files, 0);
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break;
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case OUTPUT_UNIFIED:
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print_context_header (files, 1);
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break;
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default:
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break;
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}
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}
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/* Call after the end of output of diffs for one file.
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Close OUTFILE and get rid of the `pr' subfork. */
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void
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finish_output ()
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{
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if (outfile != 0 && outfile != stdout)
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{
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fclose (outfile);
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wait (0);
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}
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outfile = 0;
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}
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/* Compare two lines (typically one from each input file)
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according to the command line options.
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Return 1 if the lines differ, like `bcmp'. */
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int
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line_cmp (s1, len1, s2, len2)
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const char *s1, *s2;
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int len1, len2;
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{
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register const unsigned char *t1, *t2;
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register unsigned char end_char = line_end_char;
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/* Check first for exact identity.
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If that is true, return 0 immediately.
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This detects the common case of exact identity
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faster than complete comparison would. */
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if (len1 == len2 && bcmp (s1, s2, len1) == 0)
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return 0;
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/* Not exactly identical, but perhaps they match anyway
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when case or whitespace is ignored. */
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if (ignore_case_flag || ignore_space_change_flag || ignore_all_space_flag)
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{
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t1 = (const unsigned char *) s1;
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t2 = (const unsigned char *) s2;
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while (1)
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{
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register unsigned char c1 = *t1++;
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register unsigned char c2 = *t2++;
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/* Ignore horizontal whitespace if -b or -w is specified. */
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if (ignore_all_space_flag)
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{
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/* For -w, just skip past any white space. */
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while (Is_space (c1)) c1 = *t1++;
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while (Is_space (c2)) c2 = *t2++;
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}
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else if (ignore_space_change_flag)
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{
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/* For -b, advance past any sequence of whitespace in line 1
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and consider it just one Space, or nothing at all
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if it is at the end of the line. */
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if (c1 == ' ' || c1 == '\t')
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{
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while (1)
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{
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c1 = *t1++;
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if (c1 == end_char)
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break;
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if (c1 != ' ' && c1 != '\t')
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{
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--t1;
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c1 = ' ';
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break;
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}
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}
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}
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/* Likewise for line 2. */
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if (c2 == ' ' || c2 == '\t')
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{
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while (1)
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{
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c2 = *t2++;
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if (c2 == end_char)
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break;
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if (c2 != ' ' && c2 != '\t')
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{
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--t2;
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c2 = ' ';
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break;
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}
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}
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}
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}
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/* Upcase all letters if -i is specified. */
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if (ignore_case_flag)
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{
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if (islower (c1))
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c1 = toupper (c1);
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if (islower (c2))
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c2 = toupper (c2);
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}
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if (c1 != c2)
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break;
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if (c1 == end_char)
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return 0;
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}
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}
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return (1);
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}
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/* Find the consecutive changes at the start of the script START.
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Return the last link before the first gap. */
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struct change *
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find_change (start)
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struct change *start;
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{
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return start;
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}
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struct change *
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find_reverse_change (start)
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struct change *start;
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{
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return start;
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}
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/* Divide SCRIPT into pieces by calling HUNKFUN and
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print each piece with PRINTFUN.
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Both functions take one arg, an edit script.
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HUNKFUN is called with the tail of the script
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and returns the last link that belongs together with the start
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of the tail.
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PRINTFUN takes a subscript which belongs together (with a null
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link at the end) and prints it. */
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void
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print_script (script, hunkfun, printfun)
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struct change *script;
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struct change * (*hunkfun) ();
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void (*printfun) ();
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{
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struct change *next = script;
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while (next)
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{
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struct change *this, *end;
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/* Find a set of changes that belong together. */
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this = next;
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end = (*hunkfun) (next);
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/* Disconnect them from the rest of the changes,
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making them a hunk, and remember the rest for next iteration. */
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next = end->link;
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end->link = NULL;
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#ifdef DEBUG
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debug_script (this);
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#endif
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/* Print this hunk. */
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(*printfun) (this);
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/* Reconnect the script so it will all be freed properly. */
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end->link = next;
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}
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}
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/* Print the text of a single line LINE,
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flagging it with the characters in LINE_FLAG (which say whether
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the line is inserted, deleted, changed, etc.). */
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void
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print_1_line (line_flag, line)
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const char *line_flag;
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const char * const *line;
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{
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const char *text = line[0], *limit = line[1]; /* Help the compiler. */
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FILE *out = outfile; /* Help the compiler some more. */
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const char *flag_format = 0;
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/* If -T was specified, use a Tab between the line-flag and the text.
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Otherwise use a Space (as Unix diff does).
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Print neither space nor tab if line-flags are empty. */
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if (line_flag != NULL && line_flag[0] != 0)
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{
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flag_format = tab_align_flag ? "%s\t" : "%s ";
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fprintf (out, flag_format, line_flag);
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}
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output_1_line (text, limit, flag_format, line_flag);
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if ((line_flag == NULL || line_flag[0] != 0) && limit[-1] != '\n'
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&& line_end_char == '\n')
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fprintf (out, "\n\\ No newline at end of file\n");
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}
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/* Output a line from TEXT up to LIMIT. Without -t, output verbatim.
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With -t, expand white space characters to spaces, and if FLAG_FORMAT
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is nonzero, output it with argument LINE_FLAG after every
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internal carriage return, so that tab stops continue to line up. */
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void
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output_1_line (text, limit, flag_format, line_flag)
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const char *text, *limit, *flag_format, *line_flag;
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{
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if (!tab_expand_flag)
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fwrite (text, sizeof (char), limit - text, outfile);
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else
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{
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register FILE *out = outfile;
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register char c;
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register const char *t = text;
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register unsigned column = 0;
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while (t < limit)
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switch ((c = *t++))
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{
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case '\t':
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{
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unsigned spaces = TAB_WIDTH - column % TAB_WIDTH;
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column += spaces;
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do
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putc (' ', out);
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while (--spaces);
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}
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break;
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case '\r':
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putc (c, out);
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if (flag_format && t < limit && *t != '\n')
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fprintf (out, flag_format, line_flag);
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column = 0;
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break;
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case '\b':
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if (column == 0)
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continue;
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column--;
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putc (c, out);
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break;
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default:
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if (textchar[(unsigned char) c])
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column++;
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/* fall into */
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case '\f':
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case '\v':
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putc (c, out);
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break;
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}
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}
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}
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int
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change_letter (inserts, deletes)
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int inserts, deletes;
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{
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if (!inserts)
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return 'd';
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else if (!deletes)
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return 'a';
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else
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return 'c';
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}
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/* Translate an internal line number (an index into diff's table of lines)
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into an actual line number in the input file.
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The internal line number is LNUM. FILE points to the data on the file.
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Internal line numbers count from 0 starting after the prefix.
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Actual line numbers count from 1 within the entire file. */
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int
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translate_line_number (file, lnum)
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struct file_data *file;
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int lnum;
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{
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return lnum + file->prefix_lines + 1;
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}
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void
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translate_range (file, a, b, aptr, bptr)
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struct file_data *file;
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int a, b;
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int *aptr, *bptr;
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{
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*aptr = translate_line_number (file, a - 1) + 1;
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*bptr = translate_line_number (file, b + 1) - 1;
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}
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/* Print a pair of line numbers with SEPCHAR, translated for file FILE.
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If the two numbers are identical, 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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void
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print_number_range (sepchar, file, a, b)
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char sepchar;
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struct file_data *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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fprintf (outfile, "%d%c%d", trans_a, sepchar, trans_b);
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else
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fprintf (outfile, "%d", trans_b);
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}
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/* Look at a hunk of edit script and report the range of lines in each file
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that it applies to. HUNK is the start of the hunk, which is a chain
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of `struct change'. The first and last line numbers of file 0 are stored in
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*FIRST0 and *LAST0, and likewise for file 1 in *FIRST1 and *LAST1.
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Note that these are internal line numbers that count from 0.
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If no lines from file 0 are deleted, then FIRST0 is LAST0+1.
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Also set *DELETES nonzero if any lines of file 0 are deleted
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and set *INSERTS nonzero if any lines of file 1 are inserted.
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If only ignorable lines are inserted or deleted, both are
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set to 0. */
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void
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analyze_hunk (hunk, first0, last0, first1, last1, deletes, inserts)
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struct change *hunk;
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int *first0, *last0, *first1, *last1;
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int *deletes, *inserts;
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{
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int f0, l0, f1, l1, show_from, show_to;
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int i;
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int nontrivial = !(ignore_blank_lines_flag || ignore_regexp_list);
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struct change *next;
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show_from = show_to = 0;
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f0 = hunk->line0;
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f1 = hunk->line1;
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for (next = hunk; next; next = next->link)
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{
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l0 = next->line0 + next->deleted - 1;
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l1 = next->line1 + next->inserted - 1;
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show_from += next->deleted;
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show_to += next->inserted;
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for (i = next->line0; i <= l0 && ! nontrivial; i++)
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if (!ignore_blank_lines_flag || files[0].linbuf[i][0] != '\n')
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{
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struct regexp_list *r;
|
||
const char *line = files[0].linbuf[i];
|
||
int len = files[0].linbuf[i + 1] - line;
|
||
|
||
for (r = ignore_regexp_list; r; r = r->next)
|
||
if (0 <= re_search (&r->buf, line, len, 0, len, 0))
|
||
break; /* Found a match. Ignore this line. */
|
||
/* If we got all the way through the regexp list without
|
||
finding a match, then it's nontrivial. */
|
||
if (r == NULL)
|
||
nontrivial = 1;
|
||
}
|
||
|
||
for (i = next->line1; i <= l1 && ! nontrivial; i++)
|
||
if (!ignore_blank_lines_flag || files[1].linbuf[i][0] != '\n')
|
||
{
|
||
struct regexp_list *r;
|
||
const char *line = files[1].linbuf[i];
|
||
int len = files[1].linbuf[i + 1] - line;
|
||
|
||
for (r = ignore_regexp_list; r; r = r->next)
|
||
if (0 <= re_search (&r->buf, line, len, 0, len, 0))
|
||
break; /* Found a match. Ignore this line. */
|
||
/* If we got all the way through the regexp list without
|
||
finding a match, then it's nontrivial. */
|
||
if (r == NULL)
|
||
nontrivial = 1;
|
||
}
|
||
}
|
||
|
||
*first0 = f0;
|
||
*last0 = l0;
|
||
*first1 = f1;
|
||
*last1 = l1;
|
||
|
||
/* If all inserted or deleted lines are ignorable,
|
||
tell the caller to ignore this hunk. */
|
||
|
||
if (!nontrivial)
|
||
show_from = show_to = 0;
|
||
|
||
*deletes = show_from;
|
||
*inserts = show_to;
|
||
}
|
||
|
||
/* malloc a block of memory, with fatal error message if we can't do it. */
|
||
|
||
VOID *
|
||
xmalloc (size)
|
||
unsigned size;
|
||
{
|
||
register VOID *value;
|
||
|
||
if (size == 0)
|
||
size = 1;
|
||
|
||
value = (VOID *) malloc (size);
|
||
|
||
if (!value)
|
||
fatal ("virtual memory exhausted");
|
||
return value;
|
||
}
|
||
|
||
/* realloc a block of memory, with fatal error message if we can't do it. */
|
||
|
||
VOID *
|
||
xrealloc (old, size)
|
||
VOID *old;
|
||
unsigned int size;
|
||
{
|
||
register VOID *value;
|
||
|
||
if (size == 0)
|
||
size = 1;
|
||
|
||
value = (VOID *) realloc (old, size);
|
||
|
||
if (!value)
|
||
fatal ("virtual memory exhausted");
|
||
return value;
|
||
}
|
||
|
||
/* Concatenate three strings, returning a newly malloc'd string. */
|
||
|
||
char *
|
||
concat (s1, s2, s3)
|
||
char *s1, *s2, *s3;
|
||
{
|
||
int len = strlen (s1) + strlen (s2) + strlen (s3);
|
||
char *new = (char *) xmalloc (len + 1);
|
||
strcpy (new, s1);
|
||
strcat (new, s2);
|
||
strcat (new, s3);
|
||
return new;
|
||
}
|
||
|
||
void
|
||
debug_script (sp)
|
||
struct change *sp;
|
||
{
|
||
fflush (stdout);
|
||
for (; sp; sp = sp->link)
|
||
fprintf (stderr, "%3d %3d delete %d insert %d\n",
|
||
sp->line0, sp->line1, sp->deleted, sp->inserted);
|
||
fflush (stderr);
|
||
}
|
||
|
||
#if !HAVE_MEMCHR
|
||
char *
|
||
memchr (s, c, n)
|
||
char *s;
|
||
int c;
|
||
size_t n;
|
||
{
|
||
unsigned char *p = (unsigned char *) s, *lim = p + n;
|
||
for (; p < lim; p++)
|
||
if (*p == c)
|
||
return (char *) p;
|
||
return 0;
|
||
}
|
||
#endif
|