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- /* Support routines for GNU DIFF.
- Copyright (C) 1988, 1989, 1992, 1993 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"
-
- /* Queue up one-line messages to be printed at the end,
- when -l is specified. Each message is recorded with a `struct msg'. */
-
- struct msg
- {
- struct msg *next;
- char const *format;
- char const *arg1;
- char const *arg2;
- char const *arg3;
- char const *arg4;
- };
-
- /* Head of the chain of queues messages. */
-
- static struct msg *msg_chain;
-
- /* Tail of the chain of queues messages. */
-
- static struct msg **msg_chain_end = &msg_chain;
-
- /* Use when a system call returns non-zero status.
- TEXT should normally be the file name. */
-
- void
- perror_with_name (text)
- char const *text;
- {
- int e = errno;
- fprintf (stderr, "%s: ", program);
- errno = e;
- perror (text);
- }
-
- /* Use when a system call returns non-zero status and that is fatal. */
-
- void
- pfatal_with_name (text)
- char const *text;
- {
- int e = errno;
- print_message_queue ();
- fprintf (stderr, "%s: ", program);
- errno = e;
- perror (text);
- exit (2);
- }
-
- /* Print an error message from the format-string FORMAT
- with args ARG1 and ARG2. */
-
- void
- error (format, arg, arg1)
- char const *format, *arg, *arg1;
- {
- fprintf (stderr, "%s: ", program);
- fprintf (stderr, format, arg, arg1);
- fprintf (stderr, "\n");
- }
-
- /* Print an error message containing the string TEXT, then exit. */
-
- void
- fatal (m)
- char const *m;
- {
- print_message_queue ();
- error ("%s", m, 0);
- exit (2);
- }
-
- /* Like printf, except if -l in effect then save the message and print later.
- This is used for things like "binary files differ" and "Only in ...". */
-
- void
- message (format, arg1, arg2)
- char const *format, *arg1, *arg2;
- {
- message5 (format, arg1, arg2, 0, 0);
- }
-
- void
- message5 (format, arg1, arg2, arg3, arg4)
- char const *format, *arg1, *arg2, *arg3, *arg4;
- {
- if (paginate_flag)
- {
- struct msg *new = (struct msg *) xmalloc (sizeof (struct msg));
- new->format = format;
- new->arg1 = concat (arg1, "", "");
- new->arg2 = concat (arg2, "", "");
- new->arg3 = arg3 ? concat (arg3, "", "") : 0;
- new->arg4 = arg4 ? concat (arg4, "", "") : 0;
- new->next = 0;
- *msg_chain_end = new;
- msg_chain_end = &new->next;
- }
- else
- {
- if (sdiff_help_sdiff)
- putchar (' ');
- printf (format, arg1, arg2, arg3, arg4);
- }
- }
-
- /* Output all the messages that were saved up by calls to `message'. */
-
- void
- print_message_queue ()
- {
- struct msg *m;
-
- for (m = msg_chain; m; m = m->next)
- printf (m->format, m->arg1, m->arg2, m->arg3, m->arg4);
- }
-
- /* Call before outputting the results of comparing files NAME0 and NAME1
- to set up OUTFILE, the stdio stream for the output to go to.
-
- Usually, OUTFILE is just stdout. But when -l was specified
- we fork off a `pr' and make OUTFILE a pipe to it.
- `pr' then outputs to our stdout. */
-
- static char const *current_name0;
- static char const *current_name1;
- static int current_depth;
-
- void
- setup_output (name0, name1, depth)
- char const *name0, *name1;
- int depth;
- {
- current_name0 = name0;
- current_name1 = name1;
- current_depth = depth;
- outfile = 0;
- }
-
- static pid_t pr_pid;
-
- void
- begin_output ()
- {
- char *name;
-
- if (outfile != 0)
- return;
-
- /* Construct the header of this piece of diff. */
- name = xmalloc (strlen (current_name0) + strlen (current_name1)
- + strlen (switch_string) + 7);
- /* Posix.2 section 4.17.6.1.1 specifies this format. But there are some
- bugs in the first printing (IEEE Std 1003.2-1992 p 251 l 3304):
- it says that we must print only the last component of the pathnames,
- and it requires two spaces after "diff" if there are no options.
- These requirements are silly and do not match historical practice. */
- sprintf (name, "diff%s %s %s", switch_string, current_name0, current_name1);
-
- if (paginate_flag)
- {
- int pipes[2];
-
- /* Fork a `pr' and make OUTFILE a pipe to it. */
- if (pipe (pipes) < 0)
- pfatal_with_name ("pipe");
-
- fflush (stdout);
-
- pr_pid = vfork ();
- if (pr_pid < 0)
- pfatal_with_name ("vfork");
-
- if (pr_pid == 0)
- {
- close (pipes[1]);
- if (pipes[0] != STDIN_FILENO)
- {
- if (dup2 (pipes[0], STDIN_FILENO) < 0)
- pfatal_with_name ("dup2");
- close (pipes[0]);
- }
-
- execl (PR_FILE_NAME, PR_FILE_NAME, "-f", "-h", name, 0);
- pfatal_with_name (PR_FILE_NAME);
- }
- else
- {
- close (pipes[0]);
- outfile = fdopen (pipes[1], "w");
- }
- }
- else
- {
-
- /* If -l was not specified, output the diff straight to `stdout'. */
-
- outfile = stdout;
-
- /* If handling multiple files (because scanning a directory),
- print which files the following output is about. */
- if (current_depth > 0)
- printf ("%s\n", name);
- }
-
- free (name);
-
- /* A special header is needed at the beginning of context output. */
- switch (output_style)
- {
- case OUTPUT_CONTEXT:
- print_context_header (files, 0);
- break;
-
- case OUTPUT_UNIFIED:
- print_context_header (files, 1);
- break;
-
- default:
- break;
- }
- }
-
- /* Call after the end of output of diffs for one file.
- Close OUTFILE and get rid of the `pr' subfork. */
-
- void
- finish_output ()
- {
- if (outfile != 0 && outfile != stdout)
- {
- int wstatus;
- if (ferror (outfile))
- fatal ("write error");
- if (fclose (outfile) != 0)
- pfatal_with_name ("write error");
- #if HAVE_WAITPID
- if (waitpid (pr_pid, &wstatus, 0) < 0)
- pfatal_with_name ("waitpid");
- #else
- for (;;) {
- pid_t w = wait (&wstatus);
- if (w < 0)
- pfatal_with_name ("wait");
- if (w == pr_pid)
- break;
- }
- #endif
- if (! WIFEXITED (wstatus) || WEXITSTATUS (wstatus) != 0)
- fatal ("subsidiary pr failed");
- }
-
- outfile = 0;
- }
-
- /* Compare two lines (typically one from each input file)
- according to the command line options.
- Return 1 if the lines differ, like `memcmp'. */
-
- int
- line_cmp (s1, len1, s2, len2)
- char const *s1, *s2;
- size_t len1, len2;
- {
- register unsigned char const *t1, *t2;
- register unsigned char end_char = line_end_char;
-
- /* Check first for exact identity.
- If that is true, return 0 immediately.
- This detects the common case of exact identity
- faster than complete comparison would. */
-
- if (len1 == len2 && memcmp (s1, s2, len1) == 0)
- return 0;
-
- /* Not exactly identical, but perhaps they match anyway
- when case or white space is ignored. */
-
- if (ignore_case_flag | ignore_space_change_flag | ignore_all_space_flag)
- {
- t1 = (unsigned char const *) s1;
- t2 = (unsigned char const *) s2;
-
- while (1)
- {
- register unsigned char c1 = *t1++;
- register unsigned char c2 = *t2++;
-
- /* Ignore horizontal white space if -b or -w is specified. */
-
- if (ignore_all_space_flag)
- {
- /* For -w, just skip past any white space. */
- while (isspace (c1) && c1 != end_char) c1 = *t1++;
- while (isspace (c2) && c2 != end_char) c2 = *t2++;
- }
- else if (ignore_space_change_flag)
- {
- /* For -b, advance past any sequence of white space in line 1
- and consider it just one Space, or nothing at all
- if it is at the end of the line. */
- if (isspace (c1))
- {
- while (c1 != end_char)
- {
- c1 = *t1++;
- if (! isspace (c1))
- {
- --t1;
- c1 = ' ';
- break;
- }
- }
- }
-
- /* Likewise for line 2. */
- if (isspace (c2))
- {
- while (c2 != end_char)
- {
- c2 = *t2++;
- if (! isspace (c2))
- {
- --t2;
- c2 = ' ';
- break;
- }
- }
- }
- }
-
- /* Upcase all letters if -i is specified. */
-
- if (ignore_case_flag)
- {
- if (islower (c1))
- c1 = toupper (c1);
- if (islower (c2))
- c2 = toupper (c2);
- }
-
- if (c1 != c2)
- break;
- if (c1 == end_char)
- return 0;
- }
- }
-
- return (1);
- }
-
- /* Find the consecutive changes at the start of the script START.
- Return the last link before the first gap. */
-
- struct change *
- find_change (start)
- struct change *start;
- {
- return start;
- }
-
- struct change *
- find_reverse_change (start)
- struct change *start;
- {
- return start;
- }
-
- /* Divide SCRIPT into pieces by calling HUNKFUN and
- print each piece with PRINTFUN.
- Both functions take one arg, an edit script.
-
- HUNKFUN is called with the tail of the script
- and returns the last link that belongs together with the start
- of the tail.
-
- PRINTFUN takes a subscript which belongs together (with a null
- link at the end) and prints it. */
-
- void
- print_script (script, hunkfun, printfun)
- struct change *script;
- struct change * (*hunkfun) PARAMS((struct change *));
- void (*printfun) PARAMS((struct change *));
- {
- struct change *next = script;
-
- while (next)
- {
- struct change *this, *end;
-
- /* Find a set of changes that belong together. */
- this = next;
- end = (*hunkfun) (next);
-
- /* Disconnect them from the rest of the changes,
- making them a hunk, and remember the rest for next iteration. */
- next = end->link;
- end->link = 0;
- #ifdef DEBUG
- debug_script (this);
- #endif
-
- /* Print this hunk. */
- (*printfun) (this);
-
- /* Reconnect the script so it will all be freed properly. */
- end->link = next;
- }
- }
-
- /* Print the text of a single line LINE,
- flagging it with the characters in LINE_FLAG (which say whether
- the line is inserted, deleted, changed, etc.). */
-
- void
- print_1_line (line_flag, line)
- char const *line_flag;
- char const * const *line;
- {
- char const *text = line[0], *limit = line[1]; /* Help the compiler. */
- FILE *out = outfile; /* Help the compiler some more. */
- char const *flag_format = 0;
-
- /* If -T was specified, use a Tab between the line-flag and the text.
- Otherwise use a Space (as Unix diff does).
- Print neither space nor tab if line-flags are empty. */
-
- if (line_flag && *line_flag)
- {
- flag_format = tab_align_flag ? "%s\t" : "%s ";
- fprintf (out, flag_format, line_flag);
- }
-
- output_1_line (text, limit, flag_format, line_flag);
-
- if ((!line_flag || line_flag[0]) && limit[-1] != '\n'
- && line_end_char == '\n')
- fprintf (out, "\n\\ No newline at end of file\n");
- }
-
- /* Output a line from TEXT up to LIMIT. Without -t, output verbatim.
- With -t, expand white space characters to spaces, and if FLAG_FORMAT
- is nonzero, output it with argument LINE_FLAG after every
- internal carriage return, so that tab stops continue to line up. */
-
- void
- output_1_line (text, limit, flag_format, line_flag)
- char const *text, *limit, *flag_format, *line_flag;
- {
- if (!tab_expand_flag)
- fwrite (text, sizeof (char), limit - text, outfile);
- else
- {
- register FILE *out = outfile;
- register unsigned char c;
- register char const *t = text;
- register unsigned column = 0;
-
- while (t < limit)
- switch ((c = *t++))
- {
- case '\t':
- {
- unsigned spaces = TAB_WIDTH - column % TAB_WIDTH;
- column += spaces;
- do
- putc (' ', out);
- while (--spaces);
- }
- break;
-
- case '\r':
- putc (c, out);
- if (flag_format && t < limit && *t != '\n')
- fprintf (out, flag_format, line_flag);
- column = 0;
- break;
-
- case '\b':
- if (column == 0)
- continue;
- column--;
- putc (c, out);
- break;
-
- default:
- if (isprint (c))
- column++;
- putc (c, out);
- break;
- }
- }
- }
-
- int
- change_letter (inserts, deletes)
- int inserts, deletes;
- {
- if (!inserts)
- return 'd';
- else if (!deletes)
- return 'a';
- else
- return 'c';
- }
-
- /* Translate an internal line number (an index into diff's table of lines)
- into an actual line number in the input file.
- The internal line number is LNUM. FILE points to the data on the file.
-
- Internal line numbers count from 0 starting after the prefix.
- Actual line numbers count from 1 within the entire file. */
-
- int
- translate_line_number (file, lnum)
- struct file_data const *file;
- int lnum;
- {
- return lnum + file->prefix_lines + 1;
- }
-
- void
- translate_range (file, a, b, aptr, bptr)
- struct file_data const *file;
- int a, b;
- int *aptr, *bptr;
- {
- *aptr = translate_line_number (file, a - 1) + 1;
- *bptr = translate_line_number (file, b + 1) - 1;
- }
-
- /* Print a pair of line numbers with SEPCHAR, translated for file FILE.
- If the two numbers are identical, print just one number.
-
- Args A and B are internal line numbers.
- We print the translated (real) line numbers. */
-
- void
- print_number_range (sepchar, file, a, b)
- char sepchar;
- struct file_data *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%c%d", trans_a, sepchar, trans_b);
- else
- fprintf (outfile, "%d", trans_b);
- }
-
- /* Look at a hunk of edit script and report the range of lines in each file
- that it applies to. HUNK is the start of the hunk, which is a chain
- of `struct change'. The first and last line numbers of file 0 are stored in
- *FIRST0 and *LAST0, and likewise for file 1 in *FIRST1 and *LAST1.
- Note that these are internal line numbers that count from 0.
-
- If no lines from file 0 are deleted, then FIRST0 is LAST0+1.
-
- Also set *DELETES nonzero if any lines of file 0 are deleted
- and set *INSERTS nonzero if any lines of file 1 are inserted.
- If only ignorable lines are inserted or deleted, both are
- set to 0. */
-
- void
- analyze_hunk (hunk, first0, last0, first1, last1, deletes, inserts)
- struct change *hunk;
- int *first0, *last0, *first1, *last1;
- int *deletes, *inserts;
- {
- int l0, l1, show_from, show_to;
- int i;
- int trivial = ignore_blank_lines_flag || ignore_regexp_list;
- struct change *next;
-
- show_from = show_to = 0;
-
- *first0 = hunk->line0;
- *first1 = hunk->line1;
-
- next = hunk;
- do
- {
- l0 = next->line0 + next->deleted - 1;
- l1 = next->line1 + next->inserted - 1;
- show_from += next->deleted;
- show_to += next->inserted;
-
- for (i = next->line0; i <= l0 && trivial; i++)
- if (!ignore_blank_lines_flag || files[0].linbuf[i][0] != '\n')
- {
- struct regexp_list *r;
- char const *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)
- trivial = 0;
- }
-
- for (i = next->line1; i <= l1 && trivial; i++)
- if (!ignore_blank_lines_flag || files[1].linbuf[i][0] != '\n')
- {
- struct regexp_list *r;
- char const *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)
- trivial = 0;
- }
- }
- while ((next = next->link) != 0);
-
- *last0 = l0;
- *last1 = l1;
-
- /* If all inserted or deleted lines are ignorable,
- tell the caller to ignore this hunk. */
-
- if (trivial)
- 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)
- size_t size;
- {
- register VOID *value;
-
- if (size == 0)
- size = 1;
-
- value = (VOID *) malloc (size);
-
- if (!value)
- fatal ("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;
- size_t size;
- {
- register VOID *value;
-
- if (size == 0)
- size = 1;
-
- value = (VOID *) realloc (old, size);
-
- if (!value)
- fatal ("memory exhausted");
- return value;
- }
-
- /* Concatenate three strings, returning a newly malloc'd string. */
-
- char *
- concat (s1, s2, s3)
- char const *s1, *s2, *s3;
- {
- size_t len = strlen (s1) + strlen (s2) + strlen (s3);
- char *new = xmalloc (len + 1);
- sprintf (new, "%s%s%s", s1, s2, s3);
- return new;
- }
-
- /* Yield the newly malloc'd pathname
- of the file in DIR whose filename is FILE. */
-
- char *
- dir_file_pathname (dir, file)
- char const *dir, *file;
- {
- return concat (dir, "/" + (*dir && dir[strlen (dir) - 1] == '/'), file);
- }
-
- 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 const *s;
- int c;
- size_t n;
- {
- unsigned char const *p = (unsigned char const *) s, *lim = p + n;
- for (; p < lim; p++)
- if (*p == c)
- return (char *) p;
- return 0;
- }
- #endif
-