/* Context-format output routines for GNU DIFF.
Copyright (C) 1988-1989, 1991-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
2015-2017 Free Software Foundation, Inc.
This file is part of GNU DIFF.
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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>. */
#include "diff.h"
#include "c-ctype.h"
#include <stat-time.h>
#include <strftime.h>
static char const *find_function (char const * const *, lin);
static struct change *find_hunk (struct change *);
static void mark_ignorable (struct change *);
static void pr_context_hunk (struct change *);
static void pr_unidiff_hunk (struct change *);
/* Last place find_function started searching from. */
static lin find_function_last_search;
/* The value find_function returned when it started searching there. */
static lin find_function_last_match;
/* Print a label for a context diff, with a file name and date or a label. */
static void
print_context_label (char const *mark,
struct file_data *inf,
char const *name,
char const *label)
{
if (label)
fprintf (outfile, "%s %s\n", mark, label);
else
{
char buf[MAX (INT_STRLEN_BOUND (int) + 32,
INT_STRLEN_BOUND (time_t) + 11)];
struct tm const *tm = localtime (&inf->stat.st_mtime);
int nsec = get_stat_mtime_ns (&inf->stat);
if (! (tm && nstrftime (buf, sizeof buf, time_format, tm, 0, nsec)))
{
verify (TYPE_IS_INTEGER (time_t));
if (LONG_MIN <= TYPE_MINIMUM (time_t)
&& TYPE_MAXIMUM (time_t) <= LONG_MAX)
{
long int sec = inf->stat.st_mtime;
sprintf (buf, "%ld.%.9d", sec, nsec);
}
else if (TYPE_MAXIMUM (time_t) <= INTMAX_MAX)
{
intmax_t sec = inf->stat.st_mtime;
sprintf (buf, "%"PRIdMAX".%.9d", sec, nsec);
}
else
{
uintmax_t sec = inf->stat.st_mtime;
sprintf (buf, "%"PRIuMAX".%.9d", sec, nsec);
}
}
fprintf (outfile, "%s %s\t%s\n", mark, name, buf);
}
}
/* Print a header for a context diff, with the file names and dates. */
void
print_context_header (struct file_data inf[], char const *const *names, bool unidiff)
{
set_color_context (HEADER_CONTEXT);
if (unidiff)
{
print_context_label ("---", &inf[0], names[0], file_label[0]);
print_context_label ("+++", &inf[1], names[1], file_label[1]);
}
else
{
print_context_label ("***", &inf[0], names[0], file_label[0]);
print_context_label ("---", &inf[1], names[1], file_label[1]);
}
set_color_context (RESET_CONTEXT);
}
/* Print an edit script in context format. */
void
print_context_script (struct change *script, bool unidiff)
{
if (ignore_blank_lines || ignore_regexp.fastmap)
mark_ignorable (script);
else
{
struct change *e;
for (e = script; e; e = e->link)
e->ignore = false;
}
find_function_last_search = - files[0].prefix_lines;
find_function_last_match = LIN_MAX;
if (unidiff)
print_script (script, find_hunk, pr_unidiff_hunk);
else
print_script (script, find_hunk, pr_context_hunk);
}
/* Print a pair of line numbers with a comma, translated for file FILE.
If the second number is not greater, use the first in place of it.
Args A and B are internal line numbers.
We print the translated (real) line numbers. */
static void
print_context_number_range (struct file_data const *file, lin a, lin b)
{
printint trans_a, trans_b;
translate_range (file, a, b, &trans_a, &trans_b);
/* 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.
POSIX 1003.1-2001 requires two line numbers separated by a comma
even if the line numbers are the same. However, this does not
match existing practice and is surely an error in the
specification. */
if (trans_b <= trans_a)
fprintf (outfile, "%"pI"d", trans_b);
else
fprintf (outfile, "%"pI"d,%"pI"d", trans_a, trans_b);
}
/* Print FUNCTION in a context header. */
static void
print_context_function (FILE *out, char const *function)
{
int i, j;
putc (' ', out);
for (i = 0; c_isspace ((unsigned char) function[i]) && function[i] != '\n'; i++)
continue;
for (j = i; j < i + 40 && function[j] != '\n'; j++)
continue;
while (i < j && c_isspace ((unsigned char) function[j - 1]))
j--;
fwrite (function + i, sizeof (char), j - i, out);
}
/* Print a portion of an edit script in context format.
HUNK is the beginning of the portion to be printed.
The end is marked by a 'link' that has been nulled out.
Prints out lines from both files, and precedes each
line with the appropriate flag-character. */
static void
pr_context_hunk (struct change *hunk)
{
lin first0, last0, first1, last1, i;
char const *prefix;
char const *function;
FILE *out;
/* Determine range of line numbers involved in each file. */
enum changes changes = analyze_hunk (hunk, &first0, &last0, &first1, &last1);
if (! changes)
return;
/* Include a context's width before and after. */
i = - files[0].prefix_lines;
first0 = MAX (first0 - context, i);
first1 = MAX (first1 - context, i);
if (last0 < files[0].valid_lines - context)
last0 += context;
else
last0 = files[0].valid_lines - 1;
if (last1 < files[1].valid_lines - context)
last1 += context;
else
last1 = files[1].valid_lines - 1;
/* If desired, find the preceding function definition line in file 0. */
function = NULL;
if (function_regexp.fastmap)
function = find_function (files[0].linbuf, first0);
begin_output ();
out = outfile;
fputs ("***************", out);
if (function)
print_context_function (out, function);
putc ('\n', out);
set_color_context (LINE_NUMBER_CONTEXT);
fputs ("*** ", out);
print_context_number_range (&files[0], first0, last0);
fputs (" ****", out);
set_color_context (RESET_CONTEXT);
putc ('\n', out);
if (changes & OLD)
{
struct change *next = hunk;
if (first0 <= last0)
set_color_context (DELETE_CONTEXT);
for (i = first0; i <= last0; i++)
{
/* Skip past changes that apply (in file 0)
only to lines before line I. */
while (next && next->line0 + next->deleted <= i)
next = next->link;
/* Compute the marking for line I. */
prefix = " ";
if (next && next->line0 <= i)
{
/* The change NEXT covers this line.
If lines were inserted here in file 1, this is "changed".
Otherwise it is "deleted". */
prefix = (next->inserted > 0 ? "!" : "-");
}
print_1_line_nl (prefix, &files[0].linbuf[i], true);
if (i == last0)
set_color_context (RESET_CONTEXT);
if (files[0].linbuf[i + 1][-1] == '\n')
putc ('\n', out);
}
}
set_color_context (LINE_NUMBER_CONTEXT);
fputs ("--- ", out);
print_context_number_range (&files[1], first1, last1);
fputs (" ----", out);
set_color_context (RESET_CONTEXT);
putc ('\n', out);
if (changes & NEW)
{
struct change *next = hunk;
if (first1 <= last1)
set_color_context (ADD_CONTEXT);
for (i = first1; i <= last1; i++)
{
/* Skip past changes that apply (in file 1)
only to lines before line I. */
while (next && next->line1 + next->inserted <= i)
next = next->link;
/* Compute the marking for line I. */
prefix = " ";
if (next && next->line1 <= i)
{
/* The change NEXT covers this line.
If lines were deleted here in file 0, this is "changed".
Otherwise it is "inserted". */
prefix = (next->deleted > 0 ? "!" : "+");
}
print_1_line_nl (prefix, &files[1].linbuf[i], true);
if (i == last1)
set_color_context (RESET_CONTEXT);
if (files[1].linbuf[i + 1][-1] == '\n')
putc ('\n', out);
}
}
}
/* Print a pair of line numbers with a comma, translated for file FILE.
If the second number is smaller, use the first in place of it.
If the numbers are equal, print just one number.
Args A and B are internal line numbers.
We print the translated (real) line numbers. */
static void
print_unidiff_number_range (struct file_data const *file, lin a, lin b)
{
printint trans_a, trans_b;
translate_range (file, a, b, &trans_a, &trans_b);
/* We can have B < A in the case of a range of no lines.
In this case, we print the line number before the range,
which is B. It would be more logical to print A, but
'patch' expects B in order to detect diffs against empty files. */
if (trans_b <= trans_a)
fprintf (outfile, trans_b < trans_a ? "%"pI"d,0" : "%"pI"d", trans_b);
else
fprintf (outfile, "%"pI"d,%"pI"d", trans_a, trans_b - trans_a + 1);
}
/* Print a portion of an edit script in unidiff format.
HUNK is the beginning of the portion to be printed.
The end is marked by a 'link' that has been nulled out.
Prints out lines from both files, and precedes each
line with the appropriate flag-character. */
static void
pr_unidiff_hunk (struct change *hunk)
{
lin first0, last0, first1, last1;
lin i, j, k;
struct change *next;
char const *function;
FILE *out;
/* Determine range of line numbers involved in each file. */
if (! analyze_hunk (hunk, &first0, &last0, &first1, &last1))
return;
/* Include a context's width before and after. */
i = - files[0].prefix_lines;
first0 = MAX (first0 - context, i);
first1 = MAX (first1 - context, i);
if (last0 < files[0].valid_lines - context)
last0 += context;
else
last0 = files[0].valid_lines - 1;
if (last1 < files[1].valid_lines - context)
last1 += context;
else
last1 = files[1].valid_lines - 1;
/* If desired, find the preceding function definition line in file 0. */
function = NULL;
if (function_regexp.fastmap)
function = find_function (files[0].linbuf, first0);
begin_output ();
out = outfile;
set_color_context (LINE_NUMBER_CONTEXT);
fputs ("@@ -", out);
print_unidiff_number_range (&files[0], first0, last0);
fputs (" +", out);
print_unidiff_number_range (&files[1], first1, last1);
fputs (" @@", out);
set_color_context (RESET_CONTEXT);
if (function)
print_context_function (out, function);
putc ('\n', out);
next = hunk;
i = first0;
j = first1;
while (i <= last0 || j <= last1)
{
/* If the line isn't a difference, output the context from file 0. */
if (!next || i < next->line0)
{
char const *const *line = &files[0].linbuf[i++];
if (! (suppress_blank_empty && **line == '\n'))
putc (initial_tab ? '\t' : ' ', out);
print_1_line (NULL, line);
j++;
}
else
{
/* For each difference, first output the deleted part. */
k = next->deleted;
if (k)
set_color_context (DELETE_CONTEXT);
while (k--)
{
char const * const *line = &files[0].linbuf[i++];
putc ('-', out);
if (initial_tab && ! (suppress_blank_empty && **line == '\n'))
putc ('\t', out);
print_1_line_nl (NULL, line, true);
if (!k)
set_color_context (RESET_CONTEXT);
if (line[1][-1] == '\n')
putc ('\n', out);
}
/* Then output the inserted part. */
k = next->inserted;
if (k)
set_color_context (ADD_CONTEXT);
while (k--)
{
char const * const *line = &files[1].linbuf[j++];
putc ('+', out);
if (initial_tab && ! (suppress_blank_empty && **line == '\n'))
putc ('\t', out);
print_1_line_nl (NULL, line, true);
if (!k)
set_color_context (RESET_CONTEXT);
if (line[1][-1] == '\n')
putc ('\n', out);
}
/* We're done with this hunk, so on to the next! */
next = next->link;
}
}
}
/* Scan a (forward-ordered) edit script for the first place that more than
2*CONTEXT unchanged lines appear, and return a pointer
to the 'struct change' for the last change before those lines. */
static struct change * _GL_ATTRIBUTE_PURE
find_hunk (struct change *start)
{
struct change *prev;
lin top0, top1;
lin thresh;
/* Threshold distance is CONTEXT if the second change is ignorable,
2 * CONTEXT + 1 otherwise. Integer overflow can't happen, due
to CONTEXT_LIM. */
lin ignorable_threshold = context;
lin non_ignorable_threshold = 2 * context + 1;
do
{
/* Compute number of first line in each file beyond this changed. */
top0 = start->line0 + start->deleted;
top1 = start->line1 + start->inserted;
prev = start;
start = start->link;
thresh = (start && start->ignore
? ignorable_threshold
: non_ignorable_threshold);
/* It is not supposed to matter which file we check in the end-test.
If it would matter, crash. */
if (start && start->line0 - top0 != start->line1 - top1)
abort ();
} while (start
/* Keep going if less than THRESH lines
elapse before the affected line. */
&& start->line0 - top0 < thresh);
return prev;
}
/* Set the 'ignore' flag properly in each change in SCRIPT.
It should be 1 if all the lines inserted or deleted in that change
are ignorable lines. */
static void
mark_ignorable (struct change *script)
{
while (script)
{
struct change *next = script->link;
lin first0, last0, first1, last1;
/* Turn this change into a hunk: detach it from the others. */
script->link = NULL;
/* Determine whether this change is ignorable. */
script->ignore = ! analyze_hunk (script,
&first0, &last0, &first1, &last1);
/* Reconnect the chain as before. */
script->link = next;
/* Advance to the following change. */
script = next;
}
}
/* Find the last function-header line in LINBUF prior to line number LINENUM.
This is a line containing a match for the regexp in 'function_regexp'.
Return the address of the text, or NULL if no function-header is found. */
static char const *
find_function (char const * const *linbuf, lin linenum)
{
lin i = linenum;
lin last = find_function_last_search;
find_function_last_search = i;
while (last <= --i)
{
/* See if this line is what we want. */
char const *line = linbuf[i];
size_t linelen = linbuf[i + 1] - line - 1;
/* FIXME: re_search's size args should be size_t, not int. */
int len = MIN (linelen, INT_MAX);
if (0 <= re_search (&function_regexp, line, len, 0, len, NULL))
{
find_function_last_match = i;
return line;
}
}
/* If we search back to where we started searching the previous time,
find the line we found last time. */
if (find_function_last_match != LIN_MAX)
return linbuf[find_function_last_match];
return NULL;
}