patch.c

制作2.6内核的CLFS时 patch包

static void
reinitialize_almost_everything (void)
{
    re_patch();
    re_input();

    input_lines = 0;
    last_frozen_line = 0;

    if (inname) {
	free (inname);
	inname = 0;
    }

    last_offset = 0;

    diff_type = NO_DIFF;

    if (revision) {
	free(revision);
	revision = 0;
    }

    reverse = reverse_flag_specified;
    skip_rest_of_patch = false;
}

static char const shortopts[] = "bB:cd:D:eEfF:g:i:lnNo:p:r:RstTuvV:x:Y:z:Z";
static struct option const longopts[] =
{
  {"backup", no_argument, NULL, 'b'},
  {"prefix", required_argument, NULL, 'B'},
  {"context", no_argument, NULL, 'c'},
  {"directory", required_argument, NULL, 'd'},
  {"ifdef", required_argument, NULL, 'D'},
  {"ed", no_argument, NULL, 'e'},
  {"remove-empty-files", no_argument, NULL, 'E'},
  {"force", no_argument, NULL, 'f'},
  {"fuzz", required_argument, NULL, 'F'},
  {"get", no_argument, NULL, 'g'},
  {"input", required_argument, NULL, 'i'},
  {"ignore-whitespace", no_argument, NULL, 'l'},
  {"normal", no_argument, NULL, 'n'},
  {"forward", no_argument, NULL, 'N'},
  {"output", required_argument, NULL, 'o'},
  {"strip", required_argument, NULL, 'p'},
  {"reject-file", required_argument, NULL, 'r'},
  {"reverse", no_argument, NULL, 'R'},
  {"quiet", no_argument, NULL, 's'},
  {"silent", no_argument, NULL, 's'},
  {"batch", no_argument, NULL, 't'},
  {"set-time", no_argument, NULL, 'T'},
  {"unified", no_argument, NULL, 'u'},
  {"version", no_argument, NULL, 'v'},
  {"version-control", required_argument, NULL, 'V'},
  {"debug", required_argument, NULL, 'x'},
  {"basename-prefix", required_argument, NULL, 'Y'},
  {"suffix", required_argument, NULL, 'z'},
  {"set-utc", no_argument, NULL, 'Z'},
  {"dry-run", no_argument, NULL, CHAR_MAX + 1},
  {"verbose", no_argument, NULL, CHAR_MAX + 2},
  {"binary", no_argument, NULL, CHAR_MAX + 3},
  {"help", no_argument, NULL, CHAR_MAX + 4},
  {"backup-if-mismatch", no_argument, NULL, CHAR_MAX + 5},
  {"no-backup-if-mismatch", no_argument, NULL, CHAR_MAX + 6},
  {"posix", no_argument, NULL, CHAR_MAX + 7},
  {"quoting-style", required_argument, NULL, CHAR_MAX + 8},
  {NULL, no_argument, NULL, 0}
};

static char const *const option_help[] =
{
"Input options:",
"",
"  -p NUM  --strip=NUM  Strip NUM leading components from file names.",
"  -F LINES  --fuzz LINES  Set the fuzz factor to LINES for inexact matching.",
"  -l  --ignore-whitespace  Ignore white space changes between patch and input.",
"",
"  -c  --context  Interpret the patch as a context difference.",
"  -e  --ed  Interpret the patch as an ed script.",
"  -n  --normal  Interpret the patch as a normal difference.",
"  -u  --unified  Interpret the patch as a unified difference.",
"",
"  -N  --forward  Ignore patches that appear to be reversed or already applied.",
"  -R  --reverse  Assume patches were created with old and new files swapped.",
"",
"  -i PATCHFILE  --input=PATCHFILE  Read patch from PATCHFILE instead of stdin.",
"",
"Output options:",
"",
"  -o FILE  --output=FILE  Output patched files to FILE.",
"  -r FILE  --reject-file=FILE  Output rejects to FILE.",
"",
"  -D NAME  --ifdef=NAME  Make merged if-then-else output using NAME.",
"  -E  --remove-empty-files  Remove output files that are empty after patching.",
"",
"  -Z  --set-utc  Set times of patched files, assuming diff uses UTC (GMT).",
"  -T  --set-time  Likewise, assuming local time.",
"",
"  --quoting-style=WORD   output file names using quoting style WORD.",
"    Valid WORDs are: literal, shell, shell-always, c, escape.",
"    Default is taken from QUOTING_STYLE env variable, or 'shell' if unset.",
"",
"Backup and version control options:",
"",
"  -b  --backup  Back up the original contents of each file.",
"  --backup-if-mismatch  Back up if the patch does not match exactly.",
"  --no-backup-if-mismatch  Back up mismatches only if otherwise requested.",
"",
"  -V STYLE  --version-control=STYLE  Use STYLE version control.",
"	STYLE is either 'simple', 'numbered', or 'existing'.",
"  -B PREFIX  --prefix=PREFIX  Prepend PREFIX to backup file names.",
"  -Y PREFIX  --basename-prefix=PREFIX  Prepend PREFIX to backup file basenames.",
"  -z SUFFIX  --suffix=SUFFIX  Append SUFFIX to backup file names.",
"",
"  -g NUM  --get=NUM  Get files from RCS etc. if positive; ask if negative.",
"",
"Miscellaneous options:",
"",
"  -t  --batch  Ask no questions; skip bad-Prereq patches; assume reversed.",
"  -f  --force  Like -t, but ignore bad-Prereq patches, and assume unreversed.",
"  -s  --quiet  --silent  Work silently unless an error occurs.",
"  --verbose  Output extra information about the work being done.",
"  --dry-run  Do not actually change any files; just print what would happen.",
"  --posix  Conform to the POSIX standard.",
"",
"  -d DIR  --directory=DIR  Change the working directory to DIR first.",
#if HAVE_SETMODE_DOS
"  --binary  Read and write data in binary mode.",
#else
"  --binary  Read and write data in binary mode (no effect on this platform).",
#endif
"",
"  -v  --version  Output version info.",
"  --help  Output this help.",
"",
"Report bugs to <" PACKAGE_BUGREPORT ">.",
0
};

static void
usage (FILE *stream, int status)
{
  char const * const *p;

  if (status != 0)
    {
      fprintf (stream, "%s: Try `%s --help' for more information.\n",
	       program_name, Argv[0]);
    }
  else
    {
      fprintf (stream, "Usage: %s [OPTION]... [ORIGFILE [PATCHFILE]]\n\n",
	       Argv[0]);
      for (p = option_help;  *p;  p++)
	fprintf (stream, "%s\n", *p);
    }

  exit (status);
}

/* Process switches and filenames.  */

static void
get_some_switches (void)
{
    register int optc;

    if (rejname)
	free (rejname);
    rejname = 0;
    if (optind == Argc)
	return;
    while ((optc = getopt_long (Argc, Argv, shortopts, longopts, (int *) 0))
	   != -1) {
	switch (optc) {
	    case 'b':
		make_backups = true;
		 /* Special hack for backward compatibility with CVS 1.9.
		    If the last 4 args are `-b SUFFIX ORIGFILE PATCHFILE',
		    treat `-b' as if it were `-b -z'.  */
		if (Argc - optind == 3
		    && strcmp (Argv[optind - 1], "-b") == 0
		    && ! (Argv[optind + 0][0] == '-' && Argv[optind + 0][1])
		    && ! (Argv[optind + 1][0] == '-' && Argv[optind + 1][1])
		    && ! (Argv[optind + 2][0] == '-' && Argv[optind + 2][1]))
		  {
		    optarg = Argv[optind++];
		    if (verbosity != SILENT)
		      say ("warning: the `-b %s' option is obsolete; use `-b -z %s' instead\n",
			   optarg, optarg);
		    goto case_z;
		  }
		break;
	    case 'B':
		if (!*optarg)
		  fatal ("backup prefix is empty");
		origprae = savestr (optarg);
		break;
	    case 'c':
		diff_type = CONTEXT_DIFF;
		break;
	    case 'd':
		if (chdir(optarg) < 0)
		  pfatal ("Can't change to directory %s", quotearg (optarg));
		break;
	    case 'D':
		do_defines = savestr (optarg);
		break;
	    case 'e':
		diff_type = ED_DIFF;
		break;
	    case 'E':
		remove_empty_files = true;
		break;
	    case 'f':
		force = true;
		break;
	    case 'F':
		maxfuzz = numeric_string (optarg, false, "fuzz factor");
		break;
	    case 'g':
		patch_get = numeric_string (optarg, true, "get option value");
		break;
	    case 'i':
		patchname = savestr (optarg);
		break;
	    case 'l':
		canonicalize = true;
		break;
	    case 'n':
		diff_type = NORMAL_DIFF;
		break;
	    case 'N':
		noreverse = true;
		break;
	    case 'o':
		if (strcmp (optarg, "-") == 0)
		  fatal ("can't output patches to standard output");
		outfile = savestr (optarg);
		break;
	    case 'p':
		strippath = numeric_string (optarg, false, "strip count");
		break;
	    case 'r':
		rejname = savestr (optarg);
		break;
	    case 'R':
		reverse = true;
		reverse_flag_specified = true;
		break;
	    case 's':
		verbosity = SILENT;
		break;
	    case 't':
		batch = true;
		break;
	    case 'T':
		set_time = true;
		break;
	    case 'u':
		diff_type = UNI_DIFF;
		break;
	    case 'v':
		version();
		exit (0);
		break;
	    case 'V':
		version_control = optarg;
		version_control_context = "--version-control or -V option";
		break;
#if DEBUGGING
	    case 'x':
		debug = numeric_string (optarg, true, "debugging option");
		break;
#endif
	    case 'Y':
		if (!*optarg)
		  fatal ("backup basename prefix is empty");
		origbase = savestr (optarg);
		break;
	    case 'z':
	    case_z:
		if (!*optarg)
		  fatal ("backup suffix is empty");
		simple_backup_suffix = savestr (optarg);
		break;
	    case 'Z':
		set_utc = true;
		break;
	    case CHAR_MAX + 1:
		dry_run = true;
		break;
	    case CHAR_MAX + 2:
		verbosity = VERBOSE;
		break;
	    case CHAR_MAX + 3:
#if HAVE_SETMODE_DOS
		binary_transput = O_BINARY;
#endif
		break;
	    case CHAR_MAX + 4:
		usage (stdout, 0);
	    case CHAR_MAX + 5:
		backup_if_mismatch = true;
		break;
	    case CHAR_MAX + 6:
		backup_if_mismatch = false;
		break;
	    case CHAR_MAX + 7:
		posixly_correct = true;
		break;
	    case CHAR_MAX + 8:
		{
		  int i = argmatch (optarg, quoting_style_args, 0, 0);
		  if (i < 0)
		    {
		      invalid_arg ("quoting style", optarg, i);
		      usage (stderr, 2);
		    }
		  set_quoting_style ((struct quoting_options *) 0,
				     (enum quoting_style) i);
		}
		break;
	    default:
		usage (stderr, 2);
	}
    }

    /* Process any filename args.  */
    if (optind < Argc)
      {
	inname = savestr (Argv[optind++]);
	invc = -1;
	if (optind < Argc)
	  {
	    patchname = savestr (Argv[optind++]);
	    if (optind < Argc)
	      {
		fprintf (stderr, "%s: %s: extra operand\n",
			 program_name, quotearg (Argv[optind]));
		usage (stderr, 2);
	      }
	  }
      }
}

/* Handle STRING (possibly negative if NEGATIVE_ALLOWED is nonzero)
   of type ARGTYPE_MSGID by converting it to an integer,
   returning the result.  */
static int
numeric_string (char const *string,
		bool negative_allowed,
		char const *argtype_msgid)
{
  int value = 0;
  char const *p = string;
  int sign = *p == '-' ? -1 : 1;

  p += *p == '-' || *p == '+';

  do
    {
      int v10 = value * 10;
      int digit = *p - '0';
      int signed_digit = sign * digit;
      int next_value = v10 + signed_digit;

      if (9 < (unsigned) digit)
	fatal ("%s %s is not a number", argtype_msgid, quotearg (string));

      if (v10 / 10 != value || (next_value < v10) != (signed_digit < 0))
	fatal ("%s %s is too large", argtype_msgid, quotearg (string));

      value = next_value;
    }
  while (*++p);

  if (value < 0 && ! negative_allowed)
    fatal ("%s %s is negative", argtype_msgid, quotearg (string));

  return value;
}

/* Attempt to find the right place to apply this hunk of patch. */

static LINENUM
locate_hunk (LINENUM fuzz)
{
    register LINENUM first_guess = pch_first () + last_offset;
    register LINENUM offset;
    LINENUM pat_lines = pch_ptrn_lines();
    LINENUM prefix_context = pch_prefix_context ();
    LINENUM suffix_context = pch_suffix_context ();
    LINENUM context = (prefix_context < suffix_context
		       ? suffix_context : prefix_context);
    LINENUM prefix_fuzz = fuzz + prefix_context - context;
    LINENUM suffix_fuzz = fuzz + suffix_context - context;
    LINENUM max_where = input_lines - (pat_lines - suffix_fuzz) + 1;
    LINENUM min_where = last_frozen_line + 1 - (prefix_context - prefix_fuzz);
    LINENUM max_pos_offset = max_where - first_guess;
    LINENUM max_neg_offset = first_guess - min_where;
    LINENUM max_offset = (max_pos_offset < max_neg_offset
			  ? max_neg_offset : max_pos_offset);

    if (!pat_lines)			/* null range matches always */
	return first_guess;

    /* Do not try lines <= 0.  */
    if (first_guess <= max_neg_offset)
	max_neg_offset = first_guess - 1;

    if (prefix_fuzz < 0)
      {
	/* Can only match start of file.  */

	if (suffix_fuzz < 0)
	  /* Can only match entire file.  */
	  if (pat_lines != input_lines || prefix_context < last_frozen_line)
	    return 0;

	offset = 1 - first_guess;
	if (last_frozen_line <= prefix_context
	    && offset <= max_pos_offset
	    && patch_match (first_guess, offset, (LINENUM) 0, suffix_fuzz))
	  {
	    last_offset += offset;
	    return first_guess + offset;
	  }
	else
	  return 0;
      }

    if (suffix_fuzz < 0)
      {
	/* Can only match end of file.  */
	offset = first_guess - (input_lines - pat_lines + 1);
	if (offset <= max_neg_offset
	    && patch_match (first_guess, -offset, prefix_fuzz, (LINENUM) 0))
	  {
	    last_offset -= offset;
	    return first_guess - offset;
	  }
	else
	  return 0;
      }

    for (offset = 0;  offset <= max_offset;  offset++) {
	char numbuf0[LINENUM_LENGTH_BOUND + 1];
	char numbuf1[LINENUM_LENGTH_BOUND + 1];
	if (offset <= max_pos_offset
	    && patch_match (first_guess, offset, prefix_fuzz, suffix_fuzz)) {
	    if (debug & 1)
	      say ("Offset changing from %s to %s\n",
		   format_linenum (numbuf0, last_offset),
		   format_linenum (numbuf1, last_offset + offset));
	    last_offset += offset;