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possible diff3 improvements
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From: |
Greg Rohling |
|
Subject: |
possible diff3 improvements |
|
Date: |
Thu, 22 Apr 2004 16:38:18 -0400 |
To whom it may concern:
I am not sure whether you guys are interested, but
I found two enhancements to diff3 that cut down on the number of
conflicts I was experiencing.
1. Use the -w option of diff to ignore white space.
2. You receive a conflict when the file mine contains an addition next
to the
location where the file yours contains a deletion, and vice versus.
To that end I modified the code to add:
1. A -w flag to allow ignoring white space.
2. A --allow-addition-deletion to allow the resolution of additions next
to deletions without a conflict.
Attached is the modified diff3.c file (modified from 2.8.7) and
a tar file containing a directory with a script (test.sh) and test files
I used
to test my modifications.
Greg Rohling
/* diff3 - compare three files line by line
Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1998, 2001,
2002, 2004 Free Software Foundation, Inc.
This program 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.
This program 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 this program; see the file COPYING.
If not, write to the Free Software Foundation,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "system.h"
#include "paths.h"
#include <stdio.h>
#include <unlocked-io.h>
#include <c-stack.h>
#include <cmpbuf.h>
#include <error.h>
#include <exitfail.h>
#include <file-type.h>
#include <getopt.h>
#include <inttostr.h>
#include <quotesys.h>
#include <version-etc.h>
#include <xalloc.h>
/* Internal data structures and macros for the diff3 program; includes
data structures for both diff3 diffs and normal diffs. */
/* Different files within a three way diff. */
#define FILE0 0
#define FILE1 1
#define FILE2 2
/* A three way diff is built from two two-way diffs; the file which
the two two-way diffs share is: */
#define FILEC FILE2
/* Different files within a two way diff.
FC is the common file, FO the other file. */
#define FO 0
#define FC 1
/* The ranges are indexed by */
#define RANGE_START 0
#define RANGE_END 1
enum diff_type {
ERROR, /* Should not be used */
ADD, /* Two way diff add */
CHANGE, /* Two way diff change */
DELETE, /* Two way diff delete */
DIFF_ALL, /* All three are different */
DIFF_1ST, /* Only the first is different */
DIFF_2ND, /* Only the second */
DIFF_3RD /* Only the third */
};
/* Two way diff */
struct diff_block {
enum diff_type correspond; /* Type of diff */
lin ranges[2][2]; /* Ranges are inclusive */
char **lines[2]; /* The actual lines (may contain nulls) */
size_t *lengths[2]; /* Line lengths (including newlines, if any) */
struct diff_block *next;
};
/* Three way diff */
struct diff3_block {
enum diff_type correspond; /* Type of diff */
lin ranges[3][2]; /* Ranges are inclusive */
char **lines[3]; /* The actual lines (may contain nulls) */
size_t *lengths[3]; /* Line lengths (including newlines, if any) */
struct diff3_block *next;
};
/* Access the ranges on a diff block. */
#define D_LOWLINE(diff, filenum) \
((diff)->ranges[filenum][RANGE_START])
#define D_HIGHLINE(diff, filenum) \
((diff)->ranges[filenum][RANGE_END])
#define D_NUMLINES(diff, filenum) \
(D_HIGHLINE (diff, filenum) - D_LOWLINE (diff, filenum) + 1)
/* Access the line numbers in a file in a diff by relative line
numbers (i.e. line number within the diff itself). Note that these
are lvalues and can be used for assignment. */
#define D_RELNUM(diff, filenum, linenum) \
((diff)->lines[filenum][linenum])
#define D_RELLEN(diff, filenum, linenum) \
((diff)->lengths[filenum][linenum])
/* And get at them directly, when that should be necessary. */
#define D_LINEARRAY(diff, filenum) \
((diff)->lines[filenum])
#define D_LENARRAY(diff, filenum) \
((diff)->lengths[filenum])
/* Next block. */
#define D_NEXT(diff) ((diff)->next)
/* Access the type of a diff3 block. */
#define D3_TYPE(diff) ((diff)->correspond)
/* Line mappings based on diffs. The first maps off the top of the
diff, the second off of the bottom. */
#define D_HIGH_MAPLINE(diff, fromfile, tofile, linenum) \
((linenum) \
- D_HIGHLINE ((diff), (fromfile)) \
+ D_HIGHLINE ((diff), (tofile)))
#define D_LOW_MAPLINE(diff, fromfile, tofile, linenum) \
((linenum) \
- D_LOWLINE ((diff), (fromfile)) \
+ D_LOWLINE ((diff), (tofile)))
/* Options variables for flags set on command line. */
/* If nonzero, treat all files as text files, never as binary. */
static bool text;
/* Ignore differences in white space */
/* These variables never initialized to zero */
static bool ignore_white_space;
/* Allow addition next to deletion */
static bool allow_addition_deletion;
/* Remove trailing carriage returns from input. */
static bool strip_trailing_cr;
/* If nonzero, write out an ed script instead of the standard diff3 format. */
static bool edscript;
/* If nonzero, in the case of overlapping diffs (type DIFF_ALL),
preserve the lines which would normally be deleted from
file 1 with a special flagging mechanism. */
static bool flagging;
/* Use a tab to align output lines (-T). */
static bool initial_tab;
/* If nonzero, do not output information for overlapping diffs. */
static bool simple_only;
/* If nonzero, do not output information for non-overlapping diffs. */
static bool overlap_only;
/* If nonzero, show information for DIFF_2ND diffs. */
static bool show_2nd;
/* If nonzero, include `:wq' at the end of the script
to write out the file being edited. */
static bool finalwrite;
/* If nonzero, output a merged file. */
static bool merge;
char *program_name;
static char *read_diff (char const *, char const *, char **);
static char *scan_diff_line (char *, char **, size_t *, char *, char);
static enum diff_type process_diff_control (char **, struct diff_block *);
static bool compare_line_list (char * const[], size_t const[], char * const[],
size_t const[], lin);
static bool copy_stringlist (char * const[], size_t const[], char *[],
size_t[], lin);
static bool output_diff3_edscript (FILE *, struct diff3_block *, int const[3],
int const[3], char const *, char const *, char const *);
static bool output_diff3_merge (FILE *, FILE *, struct diff3_block *, int
const[3], int const[3], char const *, char const *, char const *);
static struct diff3_block *create_diff3_block (lin, lin, lin, lin, lin, lin);
static struct diff3_block *make_3way_diff (struct diff_block *, struct
diff_block *);
static struct diff3_block *reverse_diff3_blocklist (struct diff3_block *);
static struct diff3_block *using_to_diff3_block (struct diff_block *[2], struct
diff_block *[2], int, int, struct diff3_block const *);
static struct diff_block *process_diff (char const *, char const *, struct
diff_block **);
static void check_stdout (void);
static void fatal (char const *) __attribute__((noreturn));
static void output_diff3 (FILE *, struct diff3_block *, int const[3], int
const[3]);
static void perror_with_exit (char const *) __attribute__((noreturn));
static void try_help (char const *, char const *) __attribute__((noreturn));
static void usage (void);
static char const *diff_program = DEFAULT_DIFF_PROGRAM;
/* Values for long options that do not have single-letter equivalents. */
enum
{
DIFF_PROGRAM_OPTION = CHAR_MAX + 1,
HELP_OPTION,
STRIP_TRAILING_CR_OPTION,
ALLOW_ADDITION_DELETION
};
static struct option const longopts[] =
{
{"diff-program", 1, 0, DIFF_PROGRAM_OPTION},
{"easy-only", 0, 0, '3'},
{"ed", 0, 0, 'e'},
{"help", 0, 0, HELP_OPTION},
{"initial-tab", 0, 0, 'T'},
{"label", 1, 0, 'L'},
{"merge", 0, 0, 'm'},
{"overlap-only", 0, 0, 'x'},
{"show-all", 0, 0, 'A'},
{"show-overlap", 0, 0, 'E'},
{"strip-trailing-cr", 0, 0, STRIP_TRAILING_CR_OPTION},
{"ignore-white-space", 0, 0, 'w'},
{"allow-addition-deletion", 0, 0, ALLOW_ADDITION_DELETION},
{"text", 0, 0, 'a'},
{"version", 0, 0, 'v'},
{0, 0, 0, 0}
};
int
main (int argc, char **argv)
{
int c, i;
int common;
int mapping[3];
int rev_mapping[3];
int incompat = 0;
bool conflicts_found;
struct diff_block *thread0, *thread1, *last_block;
struct diff3_block *diff3;
int tag_count = 0;
char *tag_strings[3];
char *commonname;
char **file;
struct stat statb;
exit_failure = 2;
initialize_main (&argc, &argv);
program_name = argv[0];
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
c_stack_action (0);
while ((c = getopt_long (argc, argv, "aeimvwx3AEL:TX", longopts, 0)) != -1)
{
switch (c)
{
case 'a':
text = true;
break;
case 'A':
show_2nd = true;
flagging = true;
incompat++;
break;
case 'x':
overlap_only = true;
incompat++;
break;
case '3':
simple_only = true;
incompat++;
break;
case 'i':
finalwrite = true;
break;
case 'm':
merge = true;
break;
case 'X':
overlap_only = true;
/* Fall through. */
case 'E':
flagging = true;
/* Fall through. */
case 'e':
incompat++;
break;
case 'T':
initial_tab = true;
break;
case STRIP_TRAILING_CR_OPTION:
strip_trailing_cr = true;
break;
case 'v':
version_etc (stdout, "diff3", PACKAGE_NAME, PACKAGE_VERSION,
"Randy Smith", (char *) 0);
check_stdout ();
return EXIT_SUCCESS;
case ALLOW_ADDITION_DELETION:
allow_addition_deletion = true;
break;
case 'w':
ignore_white_space = true;
break;
case DIFF_PROGRAM_OPTION:
diff_program = optarg;
break;
case HELP_OPTION:
usage ();
check_stdout ();
return EXIT_SUCCESS;
case 'L':
/* Handle up to three -L options. */
if (tag_count < 3)
{
tag_strings[tag_count++] = optarg;
break;
}
try_help ("too many file label options", 0);
default:
try_help (0, 0);
}
}
edscript = incompat & ~merge; /* -AeExX3 without -m implies ed script. */
show_2nd |= ~incompat & merge; /* -m without -AeExX3 implies -A. */
flagging |= ~incompat & merge;
if (incompat > 1 /* Ensure at most one of -AeExX3. */
|| finalwrite & merge /* -i -m would rewrite input file. */
|| (tag_count && ! flagging)) /* -L requires one of -AEX. */
try_help ("incompatible options", 0);
if (argc - optind != 3)
{
if (argc - optind < 3)
try_help ("missing operand after `%s'", argv[argc - 1]);
else
try_help ("extra operand `%s'", argv[optind + 3]);
}
file = &argv[optind];
for (i = tag_count; i < 3; i++)
tag_strings[i] = file[i];
/* Always compare file1 to file2, even if file2 is "-".
This is needed for -mAeExX3. Using the file0 as
the common file would produce wrong results, because if the
file0-file1 diffs didn't line up with the file0-file2 diffs
(which is entirely possible since we don't use diff's -n option),
diff3 might report phantom changes from file1 to file2.
Also, try to compare file0 to file1, because this is where
changes are expected to come from. Diffing between these pairs
of files is more likely to avoid phantom changes from file0 to file1.
Historically, the default common file was file2, so some older
applications (e.g. Emacs ediff) used file2 as the ancestor. So,
for compatibility, if this is a 3-way diff (not a merge or
edscript), prefer file2 as the common file. */
common = 2 - (edscript | merge);
if (strcmp (file[common], "-") == 0)
{
/* Sigh. We've got standard input as the common file. We can't
call diff twice on stdin. Use the other arg as the common
file instead. */
common = 3 - common;
if (strcmp (file[0], "-") == 0 || strcmp (file[common], "-") == 0)
fatal ("`-' specified for more than one input file");
}
mapping[0] = 0;
mapping[1] = 3 - common;
mapping[2] = common;
for (i = 0; i < 3; i++)
rev_mapping[mapping[i]] = i;
for (i = 0; i < 3; i++)
if (strcmp (file[i], "-") != 0)
{
if (stat (file[i], &statb) < 0)
perror_with_exit (file[i]);
else if (S_ISDIR (statb.st_mode))
error (EXIT_TROUBLE, EISDIR, "%s", file[i]);
}
#ifdef SIGCHLD
/* System V fork+wait does not work if SIGCHLD is ignored. */
signal (SIGCHLD, SIG_DFL);
#endif
/* Invoke diff twice on two pairs of input files, combine the two
diffs, and output them. */
commonname = file[rev_mapping[FILEC]];
thread1 = process_diff (file[rev_mapping[FILE1]], commonname, &last_block);
thread0 = process_diff (file[rev_mapping[FILE0]], commonname, &last_block);
diff3 = make_3way_diff (thread0, thread1);
if (edscript)
conflicts_found
= output_diff3_edscript (stdout, diff3, mapping, rev_mapping,
tag_strings[0], tag_strings[1], tag_strings[2]);
else if (merge)
{
if (! freopen (file[rev_mapping[FILE0]], "r", stdin))
perror_with_exit (file[rev_mapping[FILE0]]);
conflicts_found
= output_diff3_merge (stdin, stdout, diff3, mapping, rev_mapping,
tag_strings[0], tag_strings[1], tag_strings[2]);
if (ferror (stdin))
fatal ("read failed");
}
else
{
output_diff3 (stdout, diff3, mapping, rev_mapping);
conflicts_found = false;
}
check_stdout ();
exit (conflicts_found);
return conflicts_found;
}
static void
try_help (char const *reason_msgid, char const *operand)
{
if (reason_msgid)
error (0, 0, _(reason_msgid), operand);
error (EXIT_TROUBLE, 0,
_("Try `%s --help' for more information."), program_name);
abort ();
}
static void
check_stdout (void)
{
if (ferror (stdout))
fatal ("write failed");
else if (fclose (stdout) != 0)
perror_with_exit (_("standard output"));
}
static char const * const option_help_msgid[] = {
N_("-e --ed Output unmerged changes from OLDFILE to YOURFILE into MYFILE."),
N_("-E --show-overlap Output unmerged changes, bracketing conflicts."),
N_("-A --show-all Output all changes, bracketing conflicts."),
N_("-x --overlap-only Output overlapping changes."),
N_("-X Output overlapping changes, bracketing them."),
N_("-3 --easy-only Output unmerged nonoverlapping changes."),
"",
N_("-m --merge Output merged file instead of ed script (default -A)."),
N_("-L LABEL --label=LABEL Use LABEL instead of file name."),
N_("-i Append `w' and `q' commands to ed scripts."),
N_("-a --text Treat all files as text."),
N_("--strip-trailing-cr Strip trailing carriage return on input."),
N_("-T --initial-tab Make tabs line up by prepending a tab."),
N_("-w Ignore whitespace in differences."),
N_("-d Allow Deletion and Addition next to each other."),
N_("--diff-program=PROGRAM Use PROGRAM to compare files."),
"",
N_("-v --version Output version info."),
N_("--help Output this help."),
0
};
static void
usage (void)
{
char const * const *p;
printf (_("Usage: %s [OPTION]... MYFILE OLDFILE YOURFILE\n"),
program_name);
printf ("%s\n\n", _("Compare three files line by line."));
for (p = option_help_msgid; *p; p++)
if (**p)
printf (" %s\n", _(*p));
else
putchar ('\n');
printf ("\n%s\n%s\n\n%s\n",
_("If a FILE is `-', read standard input."),
_("Exit status is 0 if successful, 1 if conflicts, 2 if trouble."),
_("Report bugs to <address@hidden>."));
}
/* Combine the two diffs together into one.
Here is the algorithm:
File2 is shared in common between the two diffs.
Diff02 is the diff between 0 and 2.
Diff12 is the diff between 1 and 2.
1) Find the range for the first block in File2.
a) Take the lowest of the two ranges (in File2) in the two
current blocks (one from each diff) as being the low
water mark. Assign the upper end of this block as
being the high water mark and move the current block up
one. Mark the block just moved over as to be used.
b) Check the next block in the diff that the high water
mark is *not* from.
*If* the high water mark is above
the low end of the range in that block,
mark that block as to be used and move the current
block up. Set the high water mark to the max of
the high end of this block and the current. Repeat b.
2) Find the corresponding ranges in File0 (from the blocks
in diff02; line per line outside of diffs) and in File1.
Create a diff3_block, reserving space as indicated by the ranges.
3) Copy all of the pointers for file2 in. At least for now,
do memcmp's between corresponding strings in the two diffs.
4) Copy all of the pointers for file0 and 1 in. Get what is
needed from file2 (when there isn't a diff block, it's
identical to file2 within the range between diff blocks).
5) If the diff blocks used came from only one of the two
strings of diffs, then that file (i.e. the one other than
the common file in that diff) is the odd person out. If
diff blocks are used from both sets, check to see if files
0 and 1 match:
Same number of lines? If so, do a set of memcmp's (if
a memcmp matches; copy the pointer over; it'll be easier
later during comparisons). If they match, 0 & 1 are the
same. If not, all three different.
Then do it again, until the blocks are exhausted. */
/* Make a three way diff (chain of diff3_block's) from two two way
diffs (chains of diff_block's). Assume that each of the two diffs
passed are onto the same file (i.e. that each of the diffs were
made "to" the same file). Return a three way diff pointer with
numbering FILE0 = the other file in diff02, FILE1 = the other file
in diff12, and FILEC = the common file. */
static struct diff3_block *
make_3way_diff (struct diff_block *thread0, struct diff_block *thread1)
{
/* Work on the two diffs passed to it as threads. Thread number 0
is diff02, thread number 1 is diff12. USING is the base of the
list of blocks to be used to construct each block of the three
way diff; if no blocks from a particular thread are to be used,
that element of USING is 0. LAST_USING contains the last
elements on each of the using lists.
HIGH_WATER_MARK is the highest line number in the common file
described in any of the diffs in either of the USING lists.
HIGH_WATER_THREAD names the thread. Similarly BASE_WATER_MARK
and BASE_WATER_THREAD describe the lowest line number in the
common file described in any of the diffs in either of the USING
lists. HIGH_WATER_DIFF is the diff from which the
HIGH_WATER_MARK was taken.
HIGH_WATER_DIFF should always be equal to
LAST_USING[HIGH_WATER_THREAD]. OTHER_DIFF is the next diff to
check for higher water, and should always be equal to
CURRENT[HIGH_WATER_THREAD ^ 1]. OTHER_THREAD is the thread in
which the OTHER_DIFF is, and hence should always be equal to
HIGH_WATER_THREAD ^ 1.
LAST_DIFF is the last diff block produced by this routine, for
line correspondence purposes between that diff and the one
currently being worked on. It is ZERO_DIFF before any blocks
have been created. */
struct diff_block *using[2];
struct diff_block *last_using[2];
struct diff_block *current[2];
lin high_water_mark;
int high_water_thread;
int base_water_thread;
int other_thread;
struct diff_block *high_water_diff;
struct diff_block *other_diff;
struct diff3_block *result;
struct diff3_block *tmpblock;
struct diff3_block **result_end;
struct diff3_block const *last_diff3;
static struct diff3_block const zero_diff3;
int bNextRelativeToThisDiff;
/* Initialization */
result = 0;
result_end = &result;
current[0] = thread0; current[1] = thread1;
last_diff3 = &zero_diff3;
/* Sniff up the threads until we reach the end */
while (current[0] || current[1])
{
bNextRelativeToThisDiff = 1;
using[0] = using[1] = last_using[0] = last_using[1] = 0;
/* Setup low and high water threads, diffs, and marks. */
if (!current[0])
base_water_thread = 1;
else if (!current[1])
base_water_thread = 0;
else
base_water_thread =
(D_LOWLINE (current[0], FC) > D_LOWLINE (current[1], FC));
high_water_thread = base_water_thread;
high_water_diff = current[high_water_thread];
high_water_mark = D_HIGHLINE (high_water_diff, FC);
/* Make the diff you just got info from into the using class */
using[high_water_thread]
= last_using[high_water_thread]
= high_water_diff;
current[high_water_thread] = high_water_diff->next;
last_using[high_water_thread]->next = 0;
/* And mark the other diff */
other_thread = high_water_thread ^ 0x1;
other_diff = current[other_thread];
/* This is an attempt by Greg Rohling of GTRI to skip changes
that are currently showing as conflicts. They occur for the
circumstances when there is an addition in yours, and
an deletion in mine at the same location. Likewise,
a deletion in yours and an addition in mine causes the same
problem.
Under these circumstances we would like to create two diff3_blocks
instead of a conflict.
I have added the type to the diff blocks during extraction.
*/
/* First, check for allowing of this processing, and another diff
Second, check for appropriate add/delete conditions.
Third, check for in approriate range.
If all conditions are met, force skip of following loop
*/
if ( allow_addition_deletion && other_diff &&
( ( (high_water_diff->correspond == DELETE) &&
(other_diff->correspond == ADD) ) ||
( (high_water_diff->correspond == ADD) &&
(other_diff->correspond == DELETE) ) ) &&
( D_LOWLINE (other_diff, FC) <= high_water_mark + 1)
) {
/* Get pointer to correct diff (not added and delete really opposites */
struct diff_block *delete_diff;
struct diff_block *add_diff;
int delete_high, delete_low;
int add_high, add_low;
if ( high_water_diff->correspond == ADD ) {
delete_diff = high_water_diff;
add_diff = other_diff;
} else {
add_diff = high_water_diff;
delete_diff = other_diff;
}
delete_low = D_LOWLINE (delete_diff, FC);
delete_high = D_HIGHLINE (delete_diff, FC);
/* Yes, they should reversed on the addition */
add_low = D_HIGHLINE (add_diff, FC);
add_high = D_LOWLINE (add_diff, FC);
/* Make sure the add_diff does not overlap delete_diff */
if ( ( (add_low <= delete_low) || (add_low >= delete_high) ) &&
( (add_high <= delete_low) || (add_high >= delete_high) ) ) {
/* Set other_diff to zero to for different diff block */
other_diff = 0;
/* If (
* (deletion is first) and (Additions is before the deletion)
* or
* (addition is first) and (deletion is before the deletion)
* then
* the next should not be relative to this diff,
* but rather the previous.
*/
if ( ( (high_water_diff == delete_diff) && (add_low < delete_low) )
|| ( (high_water_diff == add_diff) && (add_low > delete_low) )
) {
bNextRelativeToThisDiff = 0;
}
}
}
/* Shuffle up the ladder, checking the other diff to see if it
needs to be incorporated. */
while (other_diff
&& D_LOWLINE (other_diff, FC) <= high_water_mark + 1)
{
/* Incorporate this diff into the using list. Note that
this doesn't take it off the current list */
if (using[other_thread])
last_using[other_thread]->next = other_diff;
else
using[other_thread] = other_diff;
last_using[other_thread] = other_diff;
/* Take it off the current list. Note that this following
code assumes that other_diff enters it equal to
current[high_water_thread ^ 0x1] */
current[other_thread] = current[other_thread]->next;
other_diff->next = 0;
/* Set the high_water stuff
If this comparison is equal, then this is the last pass
through this loop; since diff blocks within a given
thread cannot overlap, the high_water_mark will be
*below* the range_start of either of the next diffs. */
if (high_water_mark < D_HIGHLINE (other_diff, FC))
{
high_water_thread ^= 1;
high_water_diff = other_diff;
high_water_mark = D_HIGHLINE (other_diff, FC);
}
/* Set the other diff */
other_thread = high_water_thread ^ 0x1;
other_diff = current[other_thread];
}
/* The using lists contain a list of all of the blocks to be
included in this diff3_block. Create it. */
tmpblock = using_to_diff3_block (using, last_using,
base_water_thread, high_water_thread,
last_diff3);
if (!tmpblock)
fatal ("internal error: screwup in format of diff blocks");
/* Put it on the list. */
*result_end = tmpblock;
result_end = &tmpblock->next;
/* Set up corresponding lines correctly. */
if ( bNextRelativeToThisDiff ) {
last_diff3 = tmpblock;
}
}
return result;
}
/* Take two lists of blocks (from two separate diff threads) and put
them together into one diff3 block. Return a pointer to this diff3
block or 0 for failure.
All arguments besides using are for the convenience of the routine;
they could be derived from the using array. LAST_USING is a pair
of pointers to the last blocks in the using structure. LOW_THREAD
and HIGH_THREAD tell which threads contain the lowest and highest
line numbers for File0. LAST_DIFF3 contains the last diff produced
in the calling routine. This is used for lines mappings that
would still be identical to the state that diff ended in.
A distinction should be made in this routine between the two diffs
that are part of a normal two diff block, and the three diffs that
are part of a diff3_block. */
static struct diff3_block *
using_to_diff3_block (struct diff_block *using[2],
struct diff_block *last_using[2],
int low_thread, int high_thread,
struct diff3_block const *last_diff3)
{
lin low[2], high[2];
struct diff3_block *result;
struct diff_block *ptr;
int d;
lin i;
/* Find the range in the common file. */
lin lowc = D_LOWLINE (using[low_thread], FC);
lin highc = D_HIGHLINE (last_using[high_thread], FC);
/* Find the ranges in the other files.
If using[d] is null, that means that the file to which that diff
refers is equivalent to the common file over this range. */
for (d = 0; d < 2; d++)
if (using[d])
{
low[d] = D_LOW_MAPLINE (using[d], FC, FO, lowc);
high[d] = D_HIGH_MAPLINE (last_using[d], FC, FO, highc);
}
else
{
low[d] = D_HIGH_MAPLINE (last_diff3, FILEC, FILE0 + d, lowc);
high[d] = D_HIGH_MAPLINE (last_diff3, FILEC, FILE0 + d, highc);
}
/* Create a block with the appropriate sizes */
result = create_diff3_block (low[0], high[0], low[1], high[1], lowc, highc);
/* Copy information for the common file.
Return with a zero if any of the compares failed. */
for (d = 0; d < 2; d++)
for (ptr = using[d]; ptr; ptr = D_NEXT (ptr))
{
lin result_offset = D_LOWLINE (ptr, FC) - lowc;
if (!copy_stringlist (D_LINEARRAY (ptr, FC),
D_LENARRAY (ptr, FC),
D_LINEARRAY (result, FILEC) + result_offset,
D_LENARRAY (result, FILEC) + result_offset,
D_NUMLINES (ptr, FC)))
return 0;
}
/* Copy information for file d. First deal with anything that might be
before the first diff. */
for (d = 0; d < 2; d++)
{
struct diff_block *u = using[d];
lin lo = low[d], hi = high[d];
for (i = 0;
i + lo < (u ? D_LOWLINE (u, FO) : hi + 1);
i++)
{
D_RELNUM (result, FILE0 + d, i) = D_RELNUM (result, FILEC, i);
D_RELLEN (result, FILE0 + d, i) = D_RELLEN (result, FILEC, i);
}
for (ptr = u; ptr; ptr = D_NEXT (ptr))
{
lin result_offset = D_LOWLINE (ptr, FO) - lo;
lin linec;
if (!copy_stringlist (D_LINEARRAY (ptr, FO),
D_LENARRAY (ptr, FO),
D_LINEARRAY (result, FILE0 + d) + result_offset,
D_LENARRAY (result, FILE0 + d) + result_offset,
D_NUMLINES (ptr, FO)))
return 0;
/* Catch the lines between here and the next diff */
linec = D_HIGHLINE (ptr, FC) + 1 - lowc;
for (i = D_HIGHLINE (ptr, FO) + 1 - lo;
i < (D_NEXT (ptr) ? D_LOWLINE (D_NEXT (ptr), FO) : hi + 1) - lo;
i++)
{
D_RELNUM (result, FILE0 + d, i) = D_RELNUM (result, FILEC, linec);
D_RELLEN (result, FILE0 + d, i) = D_RELLEN (result, FILEC, linec);
linec++;
}
}
}
/* Set correspond */
if (!using[0])
D3_TYPE (result) = DIFF_2ND;
else if (!using[1])
D3_TYPE (result) = DIFF_1ST;
else
{
lin nl0 = D_NUMLINES (result, FILE0);
lin nl1 = D_NUMLINES (result, FILE1);
if (nl0 != nl1
|| !compare_line_list (D_LINEARRAY (result, FILE0),
D_LENARRAY (result, FILE0),
D_LINEARRAY (result, FILE1),
D_LENARRAY (result, FILE1),
nl0))
D3_TYPE (result) = DIFF_ALL;
else
D3_TYPE (result) = DIFF_3RD;
}
return result;
}
/* Copy pointers from a list of strings to a different list of
strings. If a spot in the second list is already filled, make sure
that it is filled with the same string; if not, return false, the copy
incomplete. Upon successful completion of the copy, return true. */
static bool
copy_stringlist (char * const fromptrs[], size_t const fromlengths[],
char *toptrs[], size_t tolengths[],
lin copynum)
{
register char * const *f = fromptrs;
register char **t = toptrs;
register size_t const *fl = fromlengths;
register size_t *tl = tolengths;
while (copynum--)
{
if (*t)
{
if (*fl != *tl || memcmp (*f, *t, *fl) != 0)
return false;
}
else
{
*t = *f;
*tl = *fl;
}
t++; f++; tl++; fl++;
}
return true;
}
/* Create a diff3_block, with ranges as specified in the arguments.
Allocate the arrays for the various pointers (and zero them) based
on the arguments passed. Return the block as a result. */
static struct diff3_block *
create_diff3_block (lin low0, lin high0,
lin low1, lin high1,
lin low2, lin high2)
{
struct diff3_block *result = xmalloc (sizeof *result);
lin numlines;
D3_TYPE (result) = ERROR;
D_NEXT (result) = 0;
/* Assign ranges */
D_LOWLINE (result, FILE0) = low0;
D_HIGHLINE (result, FILE0) = high0;
D_LOWLINE (result, FILE1) = low1;
D_HIGHLINE (result, FILE1) = high1;
D_LOWLINE (result, FILE2) = low2;
D_HIGHLINE (result, FILE2) = high2;
/* Allocate and zero space */
numlines = D_NUMLINES (result, FILE0);
if (numlines)
{
D_LINEARRAY (result, FILE0) = xcalloc (numlines, sizeof (char *));
D_LENARRAY (result, FILE0) = xcalloc (numlines, sizeof (size_t));
}
else
{
D_LINEARRAY (result, FILE0) = 0;
D_LENARRAY (result, FILE0) = 0;
}
numlines = D_NUMLINES (result, FILE1);
if (numlines)
{
D_LINEARRAY (result, FILE1) = xcalloc (numlines, sizeof (char *));
D_LENARRAY (result, FILE1) = xcalloc (numlines, sizeof (size_t));
}
else
{
D_LINEARRAY (result, FILE1) = 0;
D_LENARRAY (result, FILE1) = 0;
}
numlines = D_NUMLINES (result, FILE2);
if (numlines)
{
D_LINEARRAY (result, FILE2) = xcalloc (numlines, sizeof (char *));
D_LENARRAY (result, FILE2) = xcalloc (numlines, sizeof (size_t));
}
else
{
D_LINEARRAY (result, FILE2) = 0;
D_LENARRAY (result, FILE2) = 0;
}
/* Return */
return result;
}
/* Compare two lists of lines of text.
Return 1 if they are equivalent, 0 if not. */
static bool
compare_line_list (char * const list1[], size_t const lengths1[],
char * const list2[], size_t const lengths2[],
lin nl)
{
char * const *l1 = list1;
char * const *l2 = list2;
size_t const *lgths1 = lengths1;
size_t const *lgths2 = lengths2;
while (nl--)
if (!*l1 || !*l2 || *lgths1 != *lgths2++
|| memcmp (*l1++, *l2++, *lgths1++) != 0)
return false;
return true;
}
/* Input and parse two way diffs. */
static struct diff_block *
process_diff (char const *filea,
char const *fileb,
struct diff_block **last_block)
{
char *diff_contents;
char *diff_limit;
char *scan_diff;
enum diff_type dt;
lin i;
struct diff_block *block_list, **block_list_end, *bptr;
size_t too_many_lines = (PTRDIFF_MAX
/ MIN (sizeof *bptr->lines[1],
sizeof *bptr->lengths[1]));
diff_limit = read_diff (filea, fileb, &diff_contents);
scan_diff = diff_contents;
block_list_end = &block_list;
bptr = 0; /* Pacify `gcc -W'. */
while (scan_diff < diff_limit)
{
bptr = xmalloc (sizeof *bptr);
bptr->lines[0] = bptr->lines[1] = 0;
bptr->lengths[0] = bptr->lengths[1] = 0;
dt = process_diff_control (&scan_diff, bptr);
bptr->correspond = dt;
if (dt == ERROR || *scan_diff != '\n')
{
fprintf (stderr, _("%s: diff failed: "), program_name);
do
{
putc (*scan_diff, stderr);
}
while (*scan_diff++ != '\n');
exit (EXIT_TROUBLE);
}
scan_diff++;
/* Force appropriate ranges to be null, if necessary */
switch (dt)
{
case ADD:
bptr->ranges[0][0]++;
break;
case DELETE:
bptr->ranges[1][0]++;
break;
case CHANGE:
break;
default:
fatal ("internal error: invalid diff type in process_diff");
break;
}
/* Allocate space for the pointers for the lines from filea, and
parcel them out among these pointers */
if (dt != ADD)
{
lin numlines = D_NUMLINES (bptr, 0);
if (too_many_lines <= numlines)
xalloc_die ();
bptr->lines[0] = xmalloc (numlines * sizeof *bptr->lines[0]);
bptr->lengths[0] = xmalloc (numlines * sizeof *bptr->lengths[0]);
for (i = 0; i < numlines; i++)
scan_diff = scan_diff_line (scan_diff,
&(bptr->lines[0][i]),
&(bptr->lengths[0][i]),
diff_limit,
'<');
}
/* Get past the separator for changes */
if (dt == CHANGE)
{
if (strncmp (scan_diff, "---\n", 4))
fatal ("invalid diff format; invalid change separator");
scan_diff += 4;
}
/* Allocate space for the pointers for the lines from fileb, and
parcel them out among these pointers */
if (dt != DELETE)
{
lin numlines = D_NUMLINES (bptr, 1);
if (too_many_lines <= numlines)
xalloc_die ();
bptr->lines[1] = xmalloc (numlines * sizeof *bptr->lines[1]);
bptr->lengths[1] = xmalloc (numlines * sizeof *bptr->lengths[1]);
for (i = 0; i < numlines; i++)
scan_diff = scan_diff_line (scan_diff,
&(bptr->lines[1][i]),
&(bptr->lengths[1][i]),
diff_limit,
'>');
}
/* Place this block on the blocklist. */
*block_list_end = bptr;
block_list_end = &bptr->next;
}
*block_list_end = 0;
*last_block = bptr;
return block_list;
}
/* Skip tabs and spaces, and return the first character after them. */
static char *
skipwhite (char *s)
{
while (*s == ' ' || *s == '\t')
s++;
return s;
}
/* Read a nonnegative line number from S, returning the address of the
first character after the line number, and storing the number into
*PNUM. Return 0 if S does not point to a valid line number. */
static char *
readnum (char *s, lin *pnum)
{
unsigned char c = *s;
lin num = 0;
if (! ISDIGIT (c))
return 0;
do
{
num = c - '0' + num * 10;
c = *++s;
}
while (ISDIGIT (c));
*pnum = num;
return s;
}
/* Parse a normal format diff control string. Return the type of the
diff (ERROR if the format is bad). All of the other important
information is filled into to the structure pointed to by db, and
the string pointer (whose location is passed to this routine) is
updated to point beyond the end of the string parsed. Note that
only the ranges in the diff_block will be set by this routine.
If some specific pair of numbers has been reduced to a single
number, then both corresponding numbers in the diff block are set
to that number. In general these numbers are interpreted as ranges
inclusive, unless being used by the ADD or DELETE commands. It is
assumed that these will be special cased in a superior routine. */
static enum diff_type
process_diff_control (char **string, struct diff_block *db)
{
char *s = *string;
enum diff_type type;
/* Read first set of digits */
s = readnum (skipwhite (s), &db->ranges[0][RANGE_START]);
if (! s)
return ERROR;
/* Was that the only digit? */
s = skipwhite (s);
if (*s == ',')
{
s = readnum (s + 1, &db->ranges[0][RANGE_END]);
if (! s)
return ERROR;
}
else
db->ranges[0][RANGE_END] = db->ranges[0][RANGE_START];
/* Get the letter */
s = skipwhite (s);
switch (*s)
{
case 'a':
type = ADD;
break;
case 'c':
type = CHANGE;
break;
case 'd':
type = DELETE;
break;
default:
return ERROR; /* Bad format */
}
s++; /* Past letter */
/* Read second set of digits */
s = readnum (skipwhite (s), &db->ranges[1][RANGE_START]);
if (! s)
return ERROR;
/* Was that the only digit? */
s = skipwhite (s);
if (*s == ',')
{
s = readnum (s + 1, &db->ranges[1][RANGE_END]);
if (! s)
return ERROR;
s = skipwhite (s); /* To move to end */
}
else
db->ranges[1][RANGE_END] = db->ranges[1][RANGE_START];
*string = s;
return type;
}
static char *
read_diff (char const *filea,
char const *fileb,
char **output_placement)
{
char *diff_result;
size_t current_chunk_size, total;
int fd, wstatus, status;
int werrno = 0;
struct stat pipestat;
#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK
char const *argv[9];
char const **ap;
int fds[2];
pid_t pid;
ap = argv;
*ap++ = diff_program;
if (text)
*ap++ = "-a";
if (strip_trailing_cr)
*ap++ = "--strip-trailing-cr";
if (ignore_white_space)
*ap++ = "-w";
*ap++ = "--horizon-lines=100";
*ap++ = "--";
*ap++ = filea;
*ap++ = fileb;
*ap = 0;
if (pipe (fds) != 0)
perror_with_exit ("pipe");
pid = vfork ();
if (pid == 0)
{
/* Child */
close (fds[0]);
if (fds[1] != STDOUT_FILENO)
{
dup2 (fds[1], STDOUT_FILENO);
close (fds[1]);
}
/* The cast to (char **) is needed for portability to older
hosts with a nonstandard prototype for execvp. */
execvp (diff_program, (char **) argv);
_exit (errno == ENOENT ? 127 : 126);
}
if (pid == -1)
perror_with_exit ("fork");
close (fds[1]); /* Prevent erroneous lack of EOF */
fd = fds[0];
#else
FILE *fpipe;
char const args[] = " --horizon-lines=100 -- ";
char *command = xmalloc (quote_system_arg (0, diff_program)
+ sizeof "-a"
+ sizeof "--strip-trailing-cr"
+ sizeof args - 1
+ quote_system_arg (0, filea) + 1
+ quote_system_arg (0, fileb) + 1);
char *p = command;
p += quote_system_arg (p, diff_program);
if (text)
{
strcpy (p, " -a");
p += 3;
}
if (strip_trailing_cr)
{
strcpy (p, " --strip-trailing-cr");
p += 20;
}
strcpy (p, args);
p += sizeof args - 1;
p += quote_system_arg (p, filea);
*p++ = ' ';
p += quote_system_arg (p, fileb);
*p = 0;
errno = 0;
fpipe = popen (command, "r");
if (!fpipe)
perror_with_exit (command);
free (command);
fd = fileno (fpipe);
#endif
if (fstat (fd, &pipestat) != 0)
perror_with_exit ("fstat");
current_chunk_size = MAX (1, STAT_BLOCKSIZE (pipestat));
diff_result = xmalloc (current_chunk_size);
total = 0;
for (;;)
{
size_t bytes_to_read = current_chunk_size - total;
size_t bytes = block_read (fd, diff_result + total, bytes_to_read);
total += bytes;
if (bytes != bytes_to_read)
{
if (bytes == SIZE_MAX)
perror_with_exit (_("read failed"));
break;
}
if (PTRDIFF_MAX / 2 <= current_chunk_size)
xalloc_die ();
current_chunk_size *= 2;
diff_result = xrealloc (diff_result, current_chunk_size);
}
if (total != 0 && diff_result[total-1] != '\n')
fatal ("invalid diff format; incomplete last line");
*output_placement = diff_result;
#if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK)
wstatus = pclose (fpipe);
if (wstatus == -1)
werrno = errno;
#else
if (close (fd) != 0)
perror_with_exit ("close");
if (waitpid (pid, &wstatus, 0) < 0)
perror_with_exit ("waitpid");
#endif
status = ! werrno && WIFEXITED (wstatus) ? WEXITSTATUS (wstatus) : INT_MAX;
if (EXIT_TROUBLE <= status)
error (EXIT_TROUBLE, werrno,
_(status == 126
? "subsidiary program `%s' could not be invoked"
: status == 127
? "subsidiary program `%s' not found"
: status == INT_MAX
? "subsidiary program `%s' failed"
: "subsidiary program `%s' failed (exit status %d)"),
diff_program, status);
return diff_result + total;
}
/* Scan a regular diff line (consisting of > or <, followed by a
space, followed by text (including nulls) up to a newline.
This next routine began life as a macro and many parameters in it
are used as call-by-reference values. */
static char *
scan_diff_line (char *scan_ptr, char **set_start, size_t *set_length,
char *limit, char leadingchar)
{
char *line_ptr;
if (!(scan_ptr[0] == leadingchar
&& scan_ptr[1] == ' '))
fatal ("invalid diff format; incorrect leading line chars");
*set_start = line_ptr = scan_ptr + 2;
while (*line_ptr++ != '\n')
continue;
/* Include newline if the original line ended in a newline,
or if an edit script is being generated.
Copy any missing newline message to stderr if an edit script is being
generated, because edit scripts cannot handle missing newlines.
Return the beginning of the next line. */
*set_length = line_ptr - *set_start;
if (line_ptr < limit && *line_ptr == '\\')
{
if (edscript)
fprintf (stderr, "%s:", program_name);
else
--*set_length;
line_ptr++;
do
{
if (edscript)
putc (*line_ptr, stderr);
}
while (*line_ptr++ != '\n');
}
return line_ptr;
}
/* Output a three way diff passed as a list of diff3_block's. The
argument MAPPING is indexed by external file number (in the
argument list) and contains the internal file number (from the diff
passed). This is important because the user expects outputs in
terms of the argument list number, and the diff passed may have
been done slightly differently (if the last argument was "-", for
example). REV_MAPPING is the inverse of MAPPING. */
static void
output_diff3 (FILE *outputfile, struct diff3_block *diff,
int const mapping[3], int const rev_mapping[3])
{
int i;
int oddoneout;
char *cp;
struct diff3_block *ptr;
lin line;
size_t length;
int dontprint;
static int skew_increment[3] = { 2, 3, 1 }; /* 0==>2==>1==>3 */
char const *line_prefix = initial_tab ? "\t" : " ";
for (ptr = diff; ptr; ptr = D_NEXT (ptr))
{
char x[2];
switch (ptr->correspond)
{
case DIFF_ALL:
x[0] = 0;
dontprint = 3; /* Print them all */
oddoneout = 3; /* Nobody's odder than anyone else */
break;
case DIFF_1ST:
case DIFF_2ND:
case DIFF_3RD:
oddoneout = rev_mapping[ptr->correspond - DIFF_1ST];
x[0] = oddoneout + '1';
x[1] = 0;
dontprint = oddoneout == 0;
break;
default:
fatal ("internal error: invalid diff type passed to output");
}
fprintf (outputfile, "====%s\n", x);
/* Go 0, 2, 1 if the first and third outputs are equivalent. */
for (i = 0; i < 3;
i = (oddoneout == 1 ? skew_increment[i] : i + 1))
{
int realfile = mapping[i];
lin lowt = D_LOWLINE (ptr, realfile);
lin hight = D_HIGHLINE (ptr, realfile);
long int llowt = lowt;
long int lhight = hight;
fprintf (outputfile, "%d:", i + 1);
switch (lowt - hight)
{
case 1:
fprintf (outputfile, "%lda\n", llowt - 1);
break;
case 0:
fprintf (outputfile, "%ldc\n", llowt);
break;
default:
fprintf (outputfile, "%ld,%ldc\n", llowt, lhight);
break;
}
if (i == dontprint) continue;
if (lowt <= hight)
{
line = 0;
do
{
fprintf (outputfile, line_prefix);
cp = D_RELNUM (ptr, realfile, line);
length = D_RELLEN (ptr, realfile, line);
fwrite (cp, sizeof (char), length, outputfile);
}
while (++line < hight - lowt + 1);
if (cp[length - 1] != '\n')
fprintf (outputfile, "\n\\ %s\n",
_("No newline at end of file"));
}
}
}
}
/* Output to OUTPUTFILE the lines of B taken from FILENUM. Double any
initial '.'s; yield nonzero if any initial '.'s were doubled. */
static bool
dotlines (FILE *outputfile, struct diff3_block *b, int filenum)
{
lin i;
bool leading_dot = false;
for (i = 0;
i < D_NUMLINES (b, filenum);
i++)
{
char *line = D_RELNUM (b, filenum, i);
if (line[0] == '.')
{
leading_dot = true;
fprintf (outputfile, ".");
}
fwrite (line, sizeof (char),
D_RELLEN (b, filenum, i), outputfile);
}
return leading_dot;
}
/* Output to OUTPUTFILE a '.' line. If LEADING_DOT is true, also
output a command that removes initial '.'s starting with line START
and continuing for NUM lines. (START is long int, not lin, for
convenience with printf %ld formats.) */
static void
undotlines (FILE *outputfile, bool leading_dot, long int start, lin num)
{
fprintf (outputfile, ".\n");
if (leading_dot)
{
if (num == 1)
fprintf (outputfile, "%lds/^\\.//\n", start);
else
fprintf (outputfile, "%ld,%lds/^\\.//\n", start, start + num - 1);
}
}
/* Output a diff3 set of blocks as an ed script. This script applies
the changes between file's 2 & 3 to file 1. Take the precise
format of the ed script to be output from global variables set
during options processing. Reverse the order of
the set of diff3 blocks in DIFF; this gets
around the problems involved with changing line numbers in an ed
script.
As in `output_diff3', the variable MAPPING maps from file number
according to the argument list to file number according to the diff
passed. All files listed below are in terms of the argument list.
REV_MAPPING is the inverse of MAPPING.
FILE0, FILE1 and FILE2 are the strings to print as the names of the
three files. These may be the actual names, or may be the
arguments specified with -L.
Return 1 if conflicts were found. */
static bool
output_diff3_edscript (FILE *outputfile, struct diff3_block *diff,
int const mapping[3], int const rev_mapping[3],
char const *file0, char const *file1, char const *file2)
{
bool leading_dot;
bool conflicts_found = false;
bool conflict;
struct diff3_block *b;
for (b = reverse_diff3_blocklist (diff); b; b = b->next)
{
/* Must do mapping correctly. */
enum diff_type type
= (b->correspond == DIFF_ALL
? DIFF_ALL
: DIFF_1ST + rev_mapping[b->correspond - DIFF_1ST]);
long int low0, high0;
/* If we aren't supposed to do this output block, skip it. */
switch (type)
{
default: continue;
case DIFF_2ND: if (!show_2nd) continue; conflict = true; break;
case DIFF_3RD: if (overlap_only) continue; conflict = false; break;
case DIFF_ALL: if (simple_only) continue; conflict = flagging; break;
}
low0 = D_LOWLINE (b, mapping[FILE0]);
high0 = D_HIGHLINE (b, mapping[FILE0]);
if (conflict)
{
conflicts_found = true;
/* Mark end of conflict. */
fprintf (outputfile, "%lda\n", high0);
leading_dot = false;
if (type == DIFF_ALL)
{
if (show_2nd)
{
/* Append lines from FILE1. */
fprintf (outputfile, "||||||| %s\n", file1);
leading_dot = dotlines (outputfile, b, mapping[FILE1]);
}
/* Append lines from FILE2. */
fprintf (outputfile, "=======\n");
leading_dot |= dotlines (outputfile, b, mapping[FILE2]);
}
fprintf (outputfile, ">>>>>>> %s\n", file2);
undotlines (outputfile, leading_dot, high0 + 2,
(D_NUMLINES (b, mapping[FILE1])
+ D_NUMLINES (b, mapping[FILE2]) + 1));
/* Mark start of conflict. */
fprintf (outputfile, "%lda\n<<<<<<< %s\n", low0 - 1,
type == DIFF_ALL ? file0 : file1);
leading_dot = false;
if (type == DIFF_2ND)
{
/* Prepend lines from FILE1. */
leading_dot = dotlines (outputfile, b, mapping[FILE1]);
fprintf (outputfile, "=======\n");
}
undotlines (outputfile, leading_dot, low0 + 1,
D_NUMLINES (b, mapping[FILE1]));
}
else if (D_NUMLINES (b, mapping[FILE2]) == 0)
/* Write out a delete */
{
if (low0 == high0)
fprintf (outputfile, "%ldd\n", low0);
else
fprintf (outputfile, "%ld,%ldd\n", low0, high0);
}
else
/* Write out an add or change */
{
switch (high0 - low0)
{
case -1:
fprintf (outputfile, "%lda\n", high0);
break;
case 0:
fprintf (outputfile, "%ldc\n", high0);
break;
default:
fprintf (outputfile, "%ld,%ldc\n", low0, high0);
break;
}
undotlines (outputfile, dotlines (outputfile, b, mapping[FILE2]),
low0, D_NUMLINES (b, mapping[FILE2]));
}
}
if (finalwrite) fprintf (outputfile, "w\nq\n");
return conflicts_found;
}
/* Read from INFILE and output to OUTPUTFILE a set of diff3_blocks
DIFF as a merged file. This acts like 'ed file0
<[output_diff3_edscript]', except that it works even for binary
data or incomplete lines.
As before, MAPPING maps from arg list file number to diff file
number, REV_MAPPING is its inverse, and FILE0, FILE1, and FILE2 are
the names of the files.
Return 1 if conflicts were found. */
static bool
output_diff3_merge (FILE *infile, FILE *outputfile, struct diff3_block *diff,
int const mapping[3], int const rev_mapping[3],
char const *file0, char const *file1, char const *file2)
{
int c;
lin i;
bool conflicts_found = false;
bool conflict;
struct diff3_block *b;
lin linesread = 0;
for (b = diff; b; b = b->next)
{
/* Must do mapping correctly. */
enum diff_type type
= ((b->correspond == DIFF_ALL)
? DIFF_ALL
: DIFF_1ST + rev_mapping[b->correspond - DIFF_1ST]);
char const *format_2nd = "<<<<<<< %s\n";
/* If we aren't supposed to do this output block, skip it. */
switch (type)
{
default: continue;
case DIFF_2ND: if (!show_2nd) continue; conflict = true; break;
case DIFF_3RD: if (overlap_only) continue; conflict = false; break;
case DIFF_ALL: if (simple_only) continue; conflict = flagging;
format_2nd = "||||||| %s\n";
break;
}
/* Copy I lines from file 0. */
i = D_LOWLINE (b, FILE0) - linesread - 1;
linesread += i;
while (0 <= --i)
do
{
c = getc (infile);
if (c == EOF)
{
if (ferror (infile))
perror_with_exit (_("read failed"));
else if (feof (infile))
fatal ("input file shrank");
}
putc (c, outputfile);
}
while (c != '\n');
if (conflict)
{
conflicts_found = true;
if (type == DIFF_ALL)
{
/* Put in lines from FILE0 with bracket. */
fprintf (outputfile, "<<<<<<< %s\n", file0);
for (i = 0;
i < D_NUMLINES (b, mapping[FILE0]);
i++)
fwrite (D_RELNUM (b, mapping[FILE0], i), sizeof (char),
D_RELLEN (b, mapping[FILE0], i), outputfile);
}
if (show_2nd)
{
/* Put in lines from FILE1 with bracket. */
fprintf (outputfile, format_2nd, file1);
for (i = 0;
i < D_NUMLINES (b, mapping[FILE1]);
i++)
fwrite (D_RELNUM (b, mapping[FILE1], i), sizeof (char),
D_RELLEN (b, mapping[FILE1], i), outputfile);
}
fprintf (outputfile, "=======\n");
}
/* Put in lines from FILE2. */
for (i = 0;
i < D_NUMLINES (b, mapping[FILE2]);
i++)
fwrite (D_RELNUM (b, mapping[FILE2], i), sizeof (char),
D_RELLEN (b, mapping[FILE2], i), outputfile);
if (conflict)
fprintf (outputfile, ">>>>>>> %s\n", file2);
/* Skip I lines in file 0. */
i = D_NUMLINES (b, FILE0);
linesread += i;
while (0 <= --i)
while ((c = getc (infile)) != '\n')
if (c == EOF)
{
if (ferror (infile))
perror_with_exit (_("read failed"));
else if (feof (infile))
{
if (i || b->next)
fatal ("input file shrank");
return conflicts_found;
}
}
}
/* Copy rest of common file. */
while ((c = getc (infile)) != EOF || !(ferror (infile) | feof (infile)))
putc (c, outputfile);
return conflicts_found;
}
/* Reverse the order of the list of diff3 blocks. */
static struct diff3_block *
reverse_diff3_blocklist (struct diff3_block *diff)
{
register struct diff3_block *tmp, *next, *prev;
for (tmp = diff, prev = 0; tmp; tmp = next)
{
next = tmp->next;
tmp->next = prev;
prev = tmp;
}
return prev;
}
static void
fatal (char const *msgid)
{
error (EXIT_TROUBLE, 0, "%s", _(msgid));
abort ();
}
static void
perror_with_exit (char const *string)
{
error (EXIT_TROUBLE, errno, "%s", string);
abort ();
}
test3.tgz
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