pch.c

来自「这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易」· C语言 代码 · 共 1,866 行 · 第 1/4 页

/* reading patches */

/* $Id: pch.c,v 1.26 1997/07/21 17:59:46 eggert Exp $ */

/*
Copyright 1986, 1987, 1988 Larry Wall
Copyright 1990, 1991, 1992, 1993, 1997 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.
*/

#define XTERN extern
#include <common.h>
#include <backupfile.h>
#include <inp.h>
#include <util.h>
#undef XTERN
#define XTERN
#include <pch.h>

#define INITHUNKMAX 125			/* initial dynamic allocation size */

/* Patch (diff listing) abstract type. */

static FILE *pfp;			/* patch file pointer */
static int p_says_nonexistent[2];	/* [0] for old file, [1] for new;
		value is 0 for nonempty, 1 for empty, 2 for nonexistent */
static int p_rfc934_nesting;		/* RFC 934 nesting level */
static time_t p_timestamp[2];		/* timestamps in patch headers */
static off_t p_filesize;		/* size of the patch file */
static LINENUM p_first;			/* 1st line number */
static LINENUM p_newfirst;		/* 1st line number of replacement */
static LINENUM p_ptrn_lines;		/* # lines in pattern */
static LINENUM p_repl_lines;		/* # lines in replacement text */
static LINENUM p_end = -1;		/* last line in hunk */
static LINENUM p_max;			/* max allowed value of p_end */
static LINENUM p_prefix_context;	/* # of prefix context lines */
static LINENUM p_suffix_context;	/* # of suffix context lines */
static LINENUM p_input_line;		/* current line # from patch file */
static char **p_line;			/* the text of the hunk */
static size_t *p_len;			/* line length including \n if any */
static char *p_Char;			/* +, -, and ! */
static LINENUM hunkmax = INITHUNKMAX;	/* size of above arrays */
static int p_indent;			/* indent to patch */
static file_offset p_base;		/* where to intuit this time */
static LINENUM p_bline;			/* line # of p_base */
static file_offset p_start;		/* where intuit found a patch */
static LINENUM p_sline;			/* and the line number for it */
static LINENUM p_hunk_beg;		/* line number of current hunk */
static LINENUM p_efake = -1;		/* end of faked up lines--don't free */
static LINENUM p_bfake = -1;		/* beg of faked up lines */

enum nametype { OLD, NEW, INDEX, NONE };

static enum diff intuit_diff_type PARAMS ((void));
static enum nametype best_name PARAMS ((char * const *, int const *));
static int prefix_components PARAMS ((char *, int));
static size_t pget_line PARAMS ((int, int));
static size_t get_line PARAMS ((void));
static bool incomplete_line PARAMS ((void));
static bool grow_hunkmax PARAMS ((void));
static void malformed PARAMS ((void)) __attribute__ ((noreturn));
static void next_intuit_at PARAMS ((file_offset, LINENUM));
static void skip_to PARAMS ((file_offset, LINENUM));

/* Prepare to look for the next patch in the patch file. */

void
re_patch()
{
    p_first = 0;
    p_newfirst = 0;
    p_ptrn_lines = 0;
    p_repl_lines = 0;
    p_end = -1;
    p_max = 0;
    p_indent = 0;
}

/* Open the patch file at the beginning of time. */

void
open_patch_file(filename)
     char const *filename;
{
    file_offset file_pos = 0;
    struct stat st;
    if (!filename || !*filename || strEQ (filename, "-"))
      {
	file_offset stdin_pos;
#if HAVE_SETMODE
	if (binary_transput)
	  {
	    if (isatty (STDIN_FILENO))
	      fatal ("cannot read binary data from tty on this platform");
	    setmode (STDIN_FILENO, O_BINARY);
	  }
#endif
	if (fstat (STDIN_FILENO, &st) != 0)
	  pfatal ("fstat");
	if (S_ISREG (st.st_mode) && (stdin_pos = file_tell (stdin)) != -1)
	  {
	    pfp = stdin;
	    file_pos = stdin_pos;
	  }
	else
	  {
	    size_t charsread;
	    pfp = fopen (TMPPATNAME, "w+b");
	    if (!pfp)
	      pfatal ("can't create `%s'", TMPPATNAME);
	    for (st.st_size = 0;
		 (charsread = fread (buf, 1, bufsize, stdin)) != 0;
		 st.st_size += charsread)
	      if (fwrite (buf, 1, charsread, pfp) != charsread)
		write_fatal ();
	    if (ferror (stdin) || fclose (stdin) != 0)
	      read_fatal ();
	    if (fflush (pfp) != 0
		|| file_seek (pfp, (file_offset) 0, SEEK_SET) != 0)
	      write_fatal ();
	  }
      }
    else
      {
	pfp = fopen (filename, binary_transput ? "rb" : "r");
	if (!pfp)
	  pfatal ("can't open patch file `%s'", filename);
	if (fstat (fileno (pfp), &st) != 0)
	  pfatal ("fstat");
      }
    p_filesize = st.st_size;
    if (p_filesize != (file_offset) p_filesize)
      fatal ("patch file is too long");
    next_intuit_at (file_pos, (LINENUM) 1);
    set_hunkmax();
}

/* Make sure our dynamically realloced tables are malloced to begin with. */

void
set_hunkmax()
{
    if (!p_line)
	p_line = (char **) malloc (hunkmax * sizeof *p_line);
    if (!p_len)
	p_len = (size_t *) malloc (hunkmax * sizeof *p_len);
    if (!p_Char)
	p_Char = malloc (hunkmax * sizeof *p_Char);
}

/* Enlarge the arrays containing the current hunk of patch. */

static bool
grow_hunkmax()
{
    hunkmax *= 2;
    assert (p_line && p_len && p_Char);
    if ((p_line = (char **) realloc (p_line, hunkmax * sizeof (*p_line)))
	&& (p_len = (size_t *) realloc (p_len, hunkmax * sizeof (*p_len)))
	&& (p_Char = realloc (p_Char, hunkmax * sizeof (*p_Char))))
      return TRUE;
    if (!using_plan_a)
      memory_fatal ();
    /* Don't free previous values of p_line etc.,
       since some broken implementations free them for us.
       Whatever is null will be allocated again from within plan_a (),
       of all places.  */
    return FALSE;
}

/* True if the remainder of the patch file contains a diff of some sort. */

bool
there_is_another_patch()
{
    if (p_base != 0 && p_base >= p_filesize) {
	if (verbosity == VERBOSE)
	    say ("done\n");
	return FALSE;
    }
    if (verbosity == VERBOSE)
	say ("Hmm...");
    diff_type = intuit_diff_type();
    if (diff_type == NO_DIFF) {
	if (verbosity == VERBOSE)
	  say (p_base
	       ? "  Ignoring the trailing garbage.\ndone\n"
	       : "  I can't seem to find a patch in there anywhere.\n");
	if (! p_base && p_filesize)
	  fatal ("Only garbage was found in the patch input.");
	return FALSE;
    }
    if (skip_rest_of_patch)
      {
	Fseek (pfp, p_start, SEEK_SET);
	p_input_line = p_sline - 1;
	return TRUE;
      }
    if (verbosity == VERBOSE)
	say ("  %sooks like %s to me...\n",
	    (p_base == 0 ? "L" : "The next patch l"),
	    diff_type == UNI_DIFF ? "a unified diff" :
	    diff_type == CONTEXT_DIFF ? "a context diff" :
	    diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
	    diff_type == NORMAL_DIFF ? "a normal diff" :
	    "an ed script" );

    if (verbosity != SILENT)
      {
	if (p_indent)
	  say ("(Patch is indented %d space%s.)\n", p_indent, p_indent==1?"":"s");
	if (! inname)
	  {
	    say ("can't find file to patch at input line %ld\n",
		 p_sline);
	    say (strippath == INT_MAX
	         ? "Perhaps you should have used the -p or --strip option?\n"
		 : "Perhaps you used the wrong -p or --strip option?\n");
	  }
      }

    skip_to(p_start,p_sline);
    while (!inname) {
	if (force || batch) {
	    say ("No file to patch.  Skipping patch.\n");
	    skip_rest_of_patch = TRUE;
	    return TRUE;
	}
	ask ("File to patch: ");
	inname = fetchname (buf, 0, (time_t *) 0);
	if (inname)
	  {
	    if (stat (inname, &instat) == 0)
	      {
		inerrno = 0;
		invc = -1;
	      }
	    else
	      {
		perror (inname);
		free (inname);
		inname = 0;
	      }
	  }
	if (!inname) {
	    ask ("Skip this patch? [y] ");
	    if (*buf != 'n') {
		if (verbosity != SILENT)
		    say ("Skipping patch.\n");
		skip_rest_of_patch = TRUE;
		return TRUE;
	    }
	}
    }
    return TRUE;
}

/* Determine what kind of diff is in the remaining part of the patch file. */

static enum diff
intuit_diff_type()
{
    register char *s;
    register char *t;
    register int indent;
    register file_offset this_line = 0;
    register file_offset previous_line;
    register file_offset first_command_line = -1;
    LINENUM fcl_line = 0; /* Pacify `gcc -W'.  */
    register bool last_line_was_command = FALSE;
    register bool this_is_a_command = FALSE;
    register bool stars_last_line = FALSE;
    register bool stars_this_line = FALSE;
    enum nametype i;
    char *name[3];
    struct stat st[3];
    int stat_errno[3];
    int version_controlled[3];
    register enum diff retval;

    name[OLD] = name[NEW] = name[INDEX] = 0;
    version_controlled[OLD] = -1;
    version_controlled[NEW] = -1;
    version_controlled[INDEX] = -1;
    p_rfc934_nesting = 0;
    p_timestamp[OLD] = p_timestamp[NEW] = (time_t) -1;
    p_says_nonexistent[OLD] = p_says_nonexistent[NEW] = 0;
    Fseek (pfp, p_base, SEEK_SET);
    p_input_line = p_bline - 1;
    for (;;) {
	previous_line = this_line;
	last_line_was_command = this_is_a_command;
	stars_last_line = stars_this_line;
	this_line = file_tell (pfp);
	indent = 0;
	if (! pget_line (0, 0)) {
	    if (first_command_line >= 0) {
					/* nothing but deletes!? */
		p_start = first_command_line;
		p_sline = fcl_line;
		retval = ED_DIFF;
		goto scan_exit;
	    }
	    else {
		p_start = this_line;
		p_sline = p_input_line;
		return NO_DIFF;
	    }
	}
	for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
	    if (*s == '\t')
		indent = (indent + 8) & ~7;
	    else
		indent++;
	}
	for (t = s;  ISDIGIT (*t) || *t == ',';  t++)
	  continue;
	this_is_a_command = (ISDIGIT (*s) &&
	  (*t == 'd' || *t == 'c' || *t == 'a') );
	if (first_command_line < 0 && this_is_a_command) {
	    first_command_line = this_line;
	    fcl_line = p_input_line;
	    p_indent = indent;		/* assume this for now */
	}
	if (!stars_last_line && strnEQ(s, "*** ", 4))
	    name[OLD] = fetchname (s+4, strippath, &p_timestamp[OLD]);
	else if (strnEQ(s, "+++ ", 4))
	    /* Swap with NEW below.  */
	    name[OLD] = fetchname (s+4, strippath, &p_timestamp[OLD]);
	else if (strnEQ(s, "Index:", 6))
	    name[INDEX] = fetchname (s+6, strippath, (time_t *) 0);
	else if (strnEQ(s, "Prereq:", 7)) {
	    for (t = s + 7;  ISSPACE ((unsigned char) *t);  t++)
	      continue;
	    revision = t;
	    for (t = revision;  *t && !ISSPACE ((unsigned char) *t);  t++)
	      continue;
	    if (t == revision)
		revision = 0;
	    else {
		char oldc = *t;
		*t = '\0';
		revision = savestr (revision);
		*t = oldc;
	    }
	} else
	  {
	    for (t = s;  t[0] == '-' && t[1] == ' ';  t += 2)
	      continue;
	    if (strnEQ(t, "--- ", 4))
	      {
		time_t timestamp = (time_t) -1;
		name[NEW] = fetchname (t+4, strippath, &timestamp);
		if (timestamp != (time_t) -1)
		  {
		    p_timestamp[NEW] = timestamp;
		    p_rfc934_nesting = (t - s) >> 1;
		  }
	      }
	  }
	if ((diff_type == NO_DIFF || diff_type == ED_DIFF) &&
	  first_command_line >= 0 &&
	  strEQ(s, ".\n") ) {
	    p_indent = indent;
	    p_start = first_command_line;
	    p_sline = fcl_line;
	    retval = ED_DIFF;
	    goto scan_exit;
	}
	if ((diff_type == NO_DIFF || diff_type == UNI_DIFF)
	    && strnEQ(s, "@@ -", 4)) {

	    /* `name' and `p_timestamp' are backwards; swap them.  */
	    time_t ti = p_timestamp[OLD];
	    p_timestamp[OLD] = p_timestamp[NEW];
	    p_timestamp[NEW] = ti;
	    t = name[OLD];
	    name[OLD] = name[NEW];
	    name[NEW] = t;

	    s += 4;
	    if (! atol (s))
	      p_says_nonexistent[OLD] = 1 + ! p_timestamp[OLD];
	    while (*s != ' ' && *s != '\n')
	      s++;
	    while (*s == ' ')
	      s++;
	    if (! atol (s))
	      p_says_nonexistent[NEW] = 1 + ! p_timestamp[NEW];
	    p_indent = indent;
	    p_start = this_line;
	    p_sline = p_input_line;
	    retval = UNI_DIFF;
	    if (! ((name[OLD] || ! p_timestamp[OLD])
		   && (name[NEW] || ! p_timestamp[NEW])))
	      say ("missing header for unified diff at line %ld of patch\n",
		   p_sline);
	    goto scan_exit;
	}
	stars_this_line = strnEQ(s, "********", 8);
	if ((diff_type == NO_DIFF
	     || diff_type == CONTEXT_DIFF
	     || diff_type == NEW_CONTEXT_DIFF)
	    && stars_last_line && strnEQ (s, "*** ", 4)) {
	    s += 4;
	    if (! atol (s))
	      p_says_nonexistent[OLD] = 1 + ! p_timestamp[OLD];
	    /* if this is a new context diff the character just before */
	    /* the newline is a '*'. */
	    while (*s != '\n')
		s++;
	    p_indent = indent;
	    p_start = previous_line;
	    p_sline = p_input_line - 1;
	    retval = (*(s-1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);

	    {
	      /* Scan the first hunk to see whether the file contents
		 appear to have been deleted.  */
	      file_offset saved_p_base = p_base;
	      LINENUM saved_p_bline = p_bline;
	      Fseek (pfp, previous_line, SEEK_SET);
	      p_input_line -= 2;
	      if (another_hunk (retval, 0)
		  && ! p_repl_lines && p_newfirst == 1)
		p_says_nonexistent[NEW] = 1 + ! p_timestamp[NEW];
	      next_intuit_at (saved_p_base, saved_p_bline);
	    }

	    if (! ((name[OLD] || ! p_timestamp[OLD])
		   && (name[NEW] || ! p_timestamp[NEW])))
	      say ("missing header for context diff at line %ld of patch\n",
		   p_sline);
	    goto scan_exit;
	}
	if ((diff_type == NO_DIFF || diff_type == NORMAL_DIFF) &&
	  last_line_was_command &&
	  (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2)) ) {
	    p_start = previous_line;
	    p_sline = p_input_line - 1;
	    p_indent = indent;
	    retval = NORMAL_DIFF;
	    goto scan_exit;
	}
    }

  scan_exit:

    /* To intuit `inname', the name of the file to patch,
       use the algorithm specified by POSIX 1003.2b/D11 section 5.22.7.2
       (with some modifications if posixly_correct is zero):

       - Take the old and new names from the context header if present,