pch.c

制作2.6内核的CLFS时 patch包

	    p_strip_trailing_cr = strip_trailing_cr;
	    retval = NORMAL_DIFF;
	    goto scan_exit;
	}
    }

  scan_exit:

    /* To intuit `inname', the name of the file to patch,
       use the algorithm specified by POSIX 1003.1-2001 XCU lines 25680-26599
       (with some modifications if posixly_correct is zero):

       - Take the old and new names from the context header if present,
	 and take the index name from the `Index:' line if present and
	 if either the old and new names are both absent
	 or posixly_correct is nonzero.
	 Consider the file names to be in the order (old, new, index).
       - If some named files exist, use the first one if posixly_correct
	 is nonzero, the best one otherwise.
       - If patch_get is nonzero, and no named files exist,
	 but an RCS or SCCS master file exists,
	 use the first named file with an RCS or SCCS master.
       - If no named files exist, no RCS or SCCS master was found,
	 some names are given, posixly_correct is zero,
	 and the patch appears to create a file, then use the best name
	 requiring the creation of the fewest directories.
       - Otherwise, report failure by setting `inname' to 0;
	 this causes our invoker to ask the user for a file name.  */

    i = NONE;

    if (!inname)
      {
	enum nametype i0 = NONE;

	if (! posixly_correct && (name[OLD] || name[NEW]) && name[INDEX])
	  {
	    free (name[INDEX]);
	    name[INDEX] = 0;
	  }

	for (i = OLD;  i <= INDEX;  i++)
	  if (name[i])
	    {
	      if (i0 != NONE && strcmp (name[i0], name[i]) == 0)
		{
		  /* It's the same name as before; reuse stat results.  */
		  stat_errno[i] = stat_errno[i0];
		  if (! stat_errno[i])
		    st[i] = st[i0];
		}
	      else if (stat (name[i], &st[i]) != 0)
		stat_errno[i] = errno;
	      else
		{
		  stat_errno[i] = 0;
		  if (posixly_correct)
		    break;
		}
	      i0 = i;
	    }

	if (! posixly_correct)
	  {
	    bool is_empty;

	    i = best_name (name, stat_errno);

	    if (i == NONE && patch_get)
	      {
		enum nametype nope = NONE;

		for (i = OLD;  i <= INDEX;  i++)
		  if (name[i])
		    {
		      char const *cs;
		      char *getbuf;
		      char *diffbuf;
		      bool readonly = (outfile
				       && strcmp (outfile, name[i]) != 0);

		      if (nope == NONE || strcmp (name[nope], name[i]) != 0)
			{
			  cs = (version_controller
			        (name[i], readonly, (struct stat *) 0,
				 &getbuf, &diffbuf));
			  version_controlled[i] = !! cs;
			  if (cs)
			    {
			      if (version_get (name[i], cs, false, readonly,
					       getbuf, &st[i]))
				stat_errno[i] = 0;
			      else
				version_controlled[i] = 0;

			      free (getbuf);
			      if (diffbuf)
				free (diffbuf);

			      if (! stat_errno[i])
				break;
			    }
			}

		      nope = i;
		    }
	      }

	    is_empty = i == NONE || st[i].st_size == 0;
	    if ((! is_empty) < p_says_nonexistent[reverse ^ is_empty])
	      {
		assert (i0 != NONE);
		reverse ^=
		  ok_to_reverse
		    ("The next patch%s would %s the file %s,\nwhich %s!",
		     reverse ? ", when reversed," : "",
		     (i == NONE ? "delete"
		      : st[i].st_size == 0 ? "empty out"
		      : "create"),
		     quotearg (name[i == NONE || st[i].st_size == 0 ? i0 : i]),
		     (i == NONE ? "does not exist"
		      : st[i].st_size == 0 ? "is already empty"
		      : "already exists"));
	      }

	    if (i == NONE && p_says_nonexistent[reverse])
	      {
		int newdirs[3];
		int newdirs_min = INT_MAX;
		int distance_from_minimum[3];

		for (i = OLD;  i <= INDEX;  i++)
		  if (name[i])
		    {
		      newdirs[i] = (prefix_components (name[i], false)
				    - prefix_components (name[i], true));
		      if (newdirs[i] < newdirs_min)
			newdirs_min = newdirs[i];
		    }

		for (i = OLD;  i <= INDEX;  i++)
		  if (name[i])
		    distance_from_minimum[i] = newdirs[i] - newdirs_min;

		i = best_name (name, distance_from_minimum);
	      }
	  }
      }

    if (i == NONE)
      inerrno = -1;
    else
      {
	inname = name[i];
	name[i] = 0;
	inerrno = stat_errno[i];
	invc = version_controlled[i];
	instat = st[i];
      }

    for (i = OLD;  i <= INDEX;  i++)
      if (name[i])
	free (name[i]);

    return retval;
}

/* Count the path name components in FILENAME's prefix.
   If CHECKDIRS is true, count only existing directories.  */
static int
prefix_components (char *filename, bool checkdirs)
{
  int count = 0;
  struct stat stat_buf;
  int stat_result;
  char *f = filename + FILESYSTEM_PREFIX_LEN (filename);

  if (*f)
    while (*++f)
      if (ISSLASH (f[0]) && ! ISSLASH (f[-1]))
	{
	  if (checkdirs)
	    {
	      *f = '\0';
	      stat_result = stat (filename, &stat_buf);
	      *f = '/';
	      if (! (stat_result == 0 && S_ISDIR (stat_buf.st_mode)))
		break;
	    }

	  count++;
	}

  return count;
}

/* Return the index of the best of NAME[OLD], NAME[NEW], and NAME[INDEX].
   Ignore null names, and ignore NAME[i] if IGNORE[i] is nonzero.
   Return NONE if all names are ignored.  */
static enum nametype
best_name (char *const *name, int const *ignore)
{
  enum nametype i;
  int components[3];
  int components_min = INT_MAX;
  size_t basename_len[3];
  size_t basename_len_min = SIZE_MAX;
  size_t len[3];
  size_t len_min = SIZE_MAX;

  for (i = OLD;  i <= INDEX;  i++)
    if (name[i] && !ignore[i])
      {
	/* Take the names with the fewest prefix components.  */
	components[i] = prefix_components (name[i], false);
	if (components_min < components[i])
	  continue;
	components_min = components[i];

	/* Of those, take the names with the shortest basename.  */
	basename_len[i] = strlen (base_name (name[i]));
	if (basename_len_min < basename_len[i])
	  continue;
	basename_len_min = basename_len[i];

	/* Of those, take the shortest names.  */
	len[i] = strlen (name[i]);
	if (len_min < len[i])
	  continue;
	len_min = len[i];
      }

  /* Of those, take the first name.  */
  for (i = OLD;  i <= INDEX;  i++)
    if (name[i] && !ignore[i]
	&& components[i] == components_min
	&& basename_len[i] == basename_len_min
	&& len[i] == len_min)
      break;

  return i;
}

/* Remember where this patch ends so we know where to start up again. */

static void
next_intuit_at (file_offset file_pos, LINENUM file_line)
{
    p_base = file_pos;
    p_bline = file_line;
}

/* Basically a verbose fseek() to the actual diff listing. */

static void
skip_to (file_offset file_pos, LINENUM file_line)
{
    register FILE *i = pfp;
    register FILE *o = stdout;
    register int c;

    assert(p_base <= file_pos);
    if ((verbosity == VERBOSE || !inname) && p_base < file_pos) {
	Fseek (i, p_base, SEEK_SET);
	say ("The text leading up to this was:\n--------------------------\n");

	while (file_tell (i) < file_pos)
	  {
	    putc ('|', o);
	    do
	      {
		if ((c = getc (i)) == EOF)
		  read_fatal ();
		putc (c, o);
	      }
	    while (c != '\n');
	  }

	say ("--------------------------\n");
    }
    else
	Fseek (i, file_pos, SEEK_SET);
    p_input_line = file_line - 1;
}

/* Make this a function for better debugging.  */
static void
malformed (void)
{
    char numbuf[LINENUM_LENGTH_BOUND + 1];
    fatal ("malformed patch at line %s: %s",
	   format_linenum (numbuf, p_input_line), buf);
		/* about as informative as "Syntax error" in C */
}

/* Parse a line number from a string.
   Return the address of the first char after the number.  */
static char *
scan_linenum (char *s0, LINENUM *linenum)
{
  char *s;
  LINENUM n = 0;
  bool overflow = false;
  char numbuf[LINENUM_LENGTH_BOUND + 1];

  for (s = s0;  ISDIGIT (*s);  s++)
    {
      LINENUM new_n = 10 * n + (*s - '0');
      overflow |= new_n / 10 != n;
      n = new_n;
    }

  if (s == s0)
    fatal ("missing line number at line %s: %s",
	   format_linenum (numbuf, p_input_line), buf);

  if (overflow)
    fatal ("line number %.*s is too large at line %s: %s",
	   (int) (s - s0), s0, format_linenum (numbuf, p_input_line), buf);

  *linenum = n;
  return s;
}

/* 1 if there is more of the current diff listing to process;
   0 if not; -1 if ran out of memory. */

int
another_hunk (enum diff difftype, bool rev)
{
    register char *s;
    register LINENUM context = 0;
    register size_t chars_read;
    char numbuf0[LINENUM_LENGTH_BOUND + 1];
    char numbuf1[LINENUM_LENGTH_BOUND + 1];
    char numbuf2[LINENUM_LENGTH_BOUND + 1];
    char numbuf3[LINENUM_LENGTH_BOUND + 1];

    while (p_end >= 0) {
	if (p_end == p_efake)
	    p_end = p_bfake;		/* don't free twice */
	else
	    free(p_line[p_end]);
	p_end--;
    }
    assert(p_end == -1);
    p_efake = -1;

    p_max = hunkmax;			/* gets reduced when --- found */
    if (difftype == CONTEXT_DIFF || difftype == NEW_CONTEXT_DIFF) {
	file_offset line_beginning = file_tell (pfp);
					/* file pos of the current line */
	LINENUM repl_beginning = 0;	/* index of --- line */
	register LINENUM fillcnt = 0;	/* #lines of missing ptrn or repl */
	register LINENUM fillsrc;	/* index of first line to copy */
	register LINENUM filldst;	/* index of first missing line */
	bool ptrn_spaces_eaten = false;	/* ptrn was slightly misformed */
	bool some_context = false;	/* (perhaps internal) context seen */
	register bool repl_could_be_missing = true;
	bool ptrn_missing = false;	/* The pattern was missing.  */
	bool repl_missing = false;	/* Likewise for replacement.  */
	file_offset repl_backtrack_position = 0;
					/* file pos of first repl line */
	LINENUM repl_patch_line;	/* input line number for same */
	LINENUM repl_context;		/* context for same */
	LINENUM ptrn_prefix_context = -1; /* lines in pattern prefix context */
	LINENUM ptrn_suffix_context = -1; /* lines in pattern suffix context */
	LINENUM repl_prefix_context = -1; /* lines in replac. prefix context */
	LINENUM ptrn_copiable = 0;	/* # of copiable lines in ptrn */
	LINENUM repl_copiable = 0;	/* Likewise for replacement.  */

	/* Pacify `gcc -Wall'.  */
	fillsrc = filldst = repl_patch_line = repl_context = 0;

	chars_read = get_line ();
	if (chars_read == (size_t) -1
	    || chars_read <= 8
	    || strncmp (buf, "********", 8) != 0) {
	    next_intuit_at(line_beginning,p_input_line);
	    return chars_read == (size_t) -1 ? -1 : 0;
	}
	p_hunk_beg = p_input_line + 1;
	while (p_end < p_max) {
	    chars_read = get_line ();
	    if (chars_read == (size_t) -1)
	      return -1;
	    if (!chars_read) {
		if (repl_beginning && repl_could_be_missing) {
		    repl_missing = true;
		    goto hunk_done;
		}
		if (p_max - p_end < 4) {
		    strcpy (buf, "  \n");  /* assume blank lines got chopped */
		    chars_read = 3;
		} else {
		    fatal ("unexpected end of file in patch");
		}
	    }
	    p_end++;
	    if (p_end == hunkmax)
	      fatal ("unterminated hunk starting at line %s; giving up at line %s: %s",
		     format_linenum (numbuf0, pch_hunk_beg ()),
		     format_linenum (numbuf1, p_input_line), buf);
	    assert(p_end < hunkmax);
	    p_Char[p_end] = *buf;
	    p_len[p_end] = 0;
	    p_line[p_end] = 0;
	    switch (*buf) {
	    case '*':
		if (strnEQ(buf, "********", 8)) {
		    if (repl_beginning && repl_could_be_missing) {
			repl_missing = true;
			goto hunk_done;
		    }
		    else
		      fatal ("unexpected end of hunk at line %s",
			     format_linenum (numbuf0, p_input_line));
		}
		if (p_end != 0) {
		    if (repl_beginning && repl_could_be_missing) {
			repl_missing = true;
			goto hunk_done;
		    }
		    fatal ("unexpected `***' at line %s: %s",
			   format_linenum (numbuf0, p_input_line), buf);
		}
		context = 0;
		p_len[p_end] = strlen (buf);
		if (! (p_line[p_end] = savestr (buf))) {
		    p_end--;
		    return -1;
		}
		for (s = buf;  *s && !ISDIGIT (*s);  s++)
		  continue;
		if (strnEQ(s,"0,0",3))
		    remove_prefix (s, 2);
		s = scan_linenum (s, &p_first);
		if (*s == ',') {
		    while (*s && !ISDIGIT (*s))
		      s++;
		    scan_linenum (s, &p_ptrn_lines);
		    p_ptrn_lines += 1 - p_first;
		}
		else if (p_first)
		    p_ptrn_lines = 1;
		else {
		    p_ptrn_lines = 0;
		    p_first = 1;
		}
		p_max = p_ptrn_lines + 6;	/* we need this much at least */
		while (p_max >= hunkmax)
		    if (! grow_hunkmax ())
			return -1;
		p_max = hunkmax;
		break;
	    case '-':
		if (buf[1] != '-')
		  goto change_line;
		if (ptrn_prefix_context == -1)
		  ptrn_prefix_context = context;
		ptrn_suffix_context = context;
		if (repl_beginning
		    || (p_end
			!= p_ptrn_lines + 1 + (p_Char[p_end - 1] == '\n')))
		  {
		    if (p_end == 1)
		      {
			/* `Old' lines were omitted.  Set up to fill
			   them in from `new' context lines.  */
			ptrn_missing = true;
			p_end = p_ptrn_lines + 1;
			ptrn_prefix_context = ptrn_suffix_context = -1;
			fillsrc = p_end + 1;
			filldst = 1;
			fillcnt = p_ptrn_lines;
		      }
		    else if (! repl_beginning)
		      fatal ("%s `---' at line %s; check line numbers at line %s",
			     (p_end <= p_ptrn_lines
			      ? "Premature"
			      : "Overdue"),
			     format_linenum (numbuf0, p_input_line),
			     format_linenum (numbuf1, p_hunk_beg));
		    else if (! repl_could_be_missing)
		      fatal ("duplicate `---' at line %s; check line numbers at line %s",
			     format_linenum (numbuf0, p_input_line),
			     format_linenum (numbuf1,
					     p_hunk_beg + repl_beginning));
		    else
		      {
			repl_missing = true;
			goto hunk_done;
		      }
		  }
		repl_beginning = p_end;
		repl_backtrack_position = file_tell (pfp);
		repl_patch_line = p_input_line;
		repl_context = context;
		p_len[p_end] = strlen (buf);
		if (! (p_line[p_end] = savestr (buf)))
		  {
		    p_end--;