patch.c

操作系统源代码

		    s = Argv[0];
		}
		if (!isalpha(*s))
		    fatal1("Argument to -D not an identifier.\n");
		Sprintf(if_defined, "#ifdef %s\n", s);
		Sprintf(not_defined, "#ifndef %s\n", s);
		Sprintf(end_defined, "#endif /* %s */\n", s);
		break;
	    case 'e':
		diff_type = ED_DIFF;
		break;
	    case 'f':
		force = TRUE;
		break;
	    case 'F':
		if (*++s == '=')
		    s++;
		maxfuzz = atoi(s);
		break;
	    case 'l':
		canonicalize = TRUE;
		break;
	    case 'n':
		diff_type = NORMAL_DIFF;
		break;
	    case 'N':
		noreverse = TRUE;
		break;
	    case 'o':
		outname = savestr(Argv[1]);
		Argc--,Argv++;
		break;
	    case 'p':
		if (*++s == '=')
		    s++;
		strippath = atoi(s);
		break;
	    case 'r':
		Strcpy(rejname, Argv[1]);
		Argc--,Argv++;
		break;
	    case 'R':
		reverse = TRUE;
		break;
	    case 's':
		verbose = FALSE;
		break;
	    case 'S':
		skip_rest_of_patch = TRUE;
		break;
	    case 'v':
		version();
		break;
#ifdef DEBUGGING
	    case 'x':
		debug = atoi(s+1);
		break;
#endif
	    default:
		fatal2("Unrecognized switch: %s\n", Argv[0]);
	    }
	}
    }
}

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

LINENUM
locate_hunk(fuzz)
LINENUM fuzz;
{
    Reg1 LINENUM first_guess = pch_first() + last_offset;
    Reg2 LINENUM offset;
    LINENUM pat_lines = pch_ptrn_lines();
    Reg3 LINENUM max_pos_offset = input_lines - first_guess
				- pat_lines + 1; 
    Reg4 LINENUM max_neg_offset = first_guess - last_frozen_line - 1
				+ pch_context();

    if (!pat_lines)			/* null range matches always */
	return first_guess;
    if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
	max_neg_offset = first_guess - 1;
    if (first_guess <= input_lines && patch_match(first_guess, Nulline, fuzz))
	return first_guess;
    for (offset = 1; ; offset++) {
	Reg5 bool check_after = (offset <= max_pos_offset);
	Reg6 bool check_before = (offset <= max_neg_offset);

	if (check_after && patch_match(first_guess, offset, fuzz)) {
#ifdef DEBUGGING
	    if (debug & 1)
		say3("Offset changing from %ld to %ld\n", last_offset, offset);
#endif
	    last_offset = offset;
	    return first_guess+offset;
	}
	else if (check_before && patch_match(first_guess, -offset, fuzz)) {
#ifdef DEBUGGING
	    if (debug & 1)
		say3("Offset changing from %ld to %ld\n", last_offset, -offset);
#endif
	    last_offset = -offset;
	    return first_guess-offset;
	}
	else if (!check_before && !check_after)
	    return Nulline;
    }
}

/* We did not find the pattern, dump out the hunk so they can handle it. */

void
abort_hunk()
{
    Reg1 LINENUM i;
    Reg2 LINENUM pat_end = pch_end();
    /* add in last_offset to guess the same as the previous successful hunk */
    LINENUM oldfirst = pch_first() + last_offset;
    LINENUM newfirst = pch_newfirst() + last_offset;
    LINENUM oldlast = oldfirst + pch_ptrn_lines() - 1;
    LINENUM newlast = newfirst + pch_repl_lines() - 1;
    char *stars = (diff_type == NEW_CONTEXT_DIFF ? " ****" : "");
    char *minuses = (diff_type == NEW_CONTEXT_DIFF ? " ----" : " -----");

    fprintf(rejfp, "***************\n");
    for (i=0; i<=pat_end; i++) {
	switch (pch_char(i)) {
	case '*':
	    if (oldlast < oldfirst)
		fprintf(rejfp, "*** 0%s\n", stars);
	    else if (oldlast == oldfirst)
		fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
	    else
		fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst, oldlast, stars);
	    break;
	case '=':
	    if (newlast < newfirst)
		fprintf(rejfp, "--- 0%s\n", minuses);
	    else if (newlast == newfirst)
		fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
	    else
		fprintf(rejfp, "--- %ld,%ld%s\n", newfirst, newlast, minuses);
	    break;
	case '\n':
	    fprintf(rejfp, "%s", pfetch(i));
	    break;
	case ' ': case '-': case '+': case '!':
	    fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
	    break;
	default:
	    say1("Fatal internal error in abort_hunk().\n"); 
	    abort();
	}
    }
}

/* We found where to apply it (we hope), so do it. */

void
apply_hunk(where)
LINENUM where;
{
    Reg1 LINENUM old = 1;
    Reg2 LINENUM lastline = pch_ptrn_lines();
    Reg3 LINENUM new = lastline+1;
#define OUTSIDE 0
#define IN_IFNDEF 1
#define IN_IFDEF 2
#define IN_ELSE 3
    Reg4 int def_state = OUTSIDE;
    Reg5 bool R_do_defines = do_defines;
    Reg6 LINENUM pat_end = pch_end();

    where--;
    while (pch_char(new) == '=' || pch_char(new) == '\n')
	new++;
    
    while (old <= lastline) {
	if (pch_char(old) == '-') {
	    copy_till(where + old - 1);
	    if (R_do_defines) {
		if (def_state == OUTSIDE) {
		    fputs(not_defined, ofp);
		    def_state = IN_IFNDEF;
		}
		else if (def_state == IN_IFDEF) {
		    fputs(else_defined, ofp);
		    def_state = IN_ELSE;
		}
		fputs(pfetch(old), ofp);
	    }
	    last_frozen_line++;
	    old++;
	}
	else if (new > pat_end)
	    break;
	else if (pch_char(new) == '+') {
	    copy_till(where + old - 1);
	    if (R_do_defines) {
		if (def_state == IN_IFNDEF) {
		    fputs(else_defined, ofp);
		    def_state = IN_ELSE;
		}
		else if (def_state == OUTSIDE) {
		    fputs(if_defined, ofp);
		    def_state = IN_IFDEF;
		}
	    }
	    fputs(pfetch(new), ofp);
	    new++;
	}
	else {
	    if (pch_char(new) != pch_char(old)) {
		say3("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
		    pch_hunk_beg() + old,
		    pch_hunk_beg() + new);
#ifdef DEBUGGING
		say3("oldchar = '%c', newchar = '%c'\n",
		    pch_char(old), pch_char(new));
#endif
		my_exit(1);
	    }
	    if (pch_char(new) == '!') {
		copy_till(where + old - 1);
		if (R_do_defines) {
		   fputs(not_defined, ofp);
		   def_state = IN_IFNDEF;
		}
		while (pch_char(old) == '!') {
		    if (R_do_defines) {
			fputs(pfetch(old), ofp);
		    }
		    last_frozen_line++;
		    old++;
		}
		if (R_do_defines) {
		    fputs(else_defined, ofp);
		    def_state = IN_ELSE;
		}
		while (pch_char(new) == '!') {
		    fputs(pfetch(new), ofp);
		    new++;
		}
		if (R_do_defines) {
		    fputs(end_defined, ofp);
		    def_state = OUTSIDE;
		}
	    }
	    else {
		assert(pch_char(new) == ' ');
		old++;
		new++;
	    }
	}
    }
    if (new <= pat_end && pch_char(new) == '+') {
	copy_till(where + old - 1);
	if (R_do_defines) {
	    if (def_state == OUTSIDE) {
	    	fputs(if_defined, ofp);
		def_state = IN_IFDEF;
	    }
	    else if (def_state == IN_IFNDEF) {
		fputs(else_defined, ofp);
		def_state = IN_ELSE;
	    }
	}
	while (new <= pat_end && pch_char(new) == '+') {
	    fputs(pfetch(new), ofp);
	    new++;
	}
    }
    if (R_do_defines && def_state != OUTSIDE) {
	fputs(end_defined, ofp);
    }
}

/* Open the new file. */

void
init_output(name)
char *name;
{
    ofp = fopen(name, "w");
    if (ofp == Nullfp)
	fatal2("patch: can't create %s.\n", name);
}

/* Open a file to put hunks we can't locate. */

void
init_reject(name)
char *name;
{
    rejfp = fopen(name, "w");
    if (rejfp == Nullfp)
	fatal2("patch: can't create %s.\n", name);
}

/* Copy input file to output, up to wherever hunk is to be applied. */

void
copy_till(lastline)
Reg1 LINENUM lastline;
{
    Reg2 LINENUM R_last_frozen_line = last_frozen_line;

    if (R_last_frozen_line > lastline)
	say1("patch: misordered hunks! output will be garbled.\n");
    while (R_last_frozen_line < lastline) {
	dump_line(++R_last_frozen_line);
    }
    last_frozen_line = R_last_frozen_line;
}

/* Finish copying the input file to the output file. */

void
spew_output()
{
#ifdef DEBUGGING
    if (debug & 256)
	say3("il=%ld lfl=%ld\n",input_lines,last_frozen_line);
#endif
    if (input_lines)
	copy_till(input_lines);		/* dump remainder of file */
    Fclose(ofp);
    ofp = Nullfp;
}

/* Copy one line from input to output. */

void
dump_line(line)
LINENUM line;
{
    Reg1 char *s;
    Reg2 char R_newline = '\n';

    /* Note: string is not null terminated. */
    for (s=ifetch(line, 0); putc(*s, ofp) != R_newline; s++) ;
}

/* Does the patch pattern match at line base+offset? */

bool
patch_match(base, offset, fuzz)
LINENUM base;
LINENUM offset;
LINENUM fuzz;
{
    Reg1 LINENUM pline = 1 + fuzz;
    Reg2 LINENUM iline;
    Reg3 LINENUM pat_lines = pch_ptrn_lines() - fuzz;

    for (iline=base+offset+fuzz; pline <= pat_lines; pline++,iline++) {
	if (canonicalize) {
	    if (!similar(ifetch(iline, (offset >= 0)),
			 pfetch(pline),
			 pch_line_len(pline) ))
		return FALSE;
	}
	else if (strnNE(ifetch(iline, (offset >= 0)),
		   pfetch(pline),
		   pch_line_len(pline) ))
	    return FALSE;
    }
    return TRUE;
}

/* Do two lines match with canonicalized white space? */

bool
similar(a,b,len)
Reg1 char *a;
Reg2 char *b;
Reg3 int len;
{
    while (len) {
	if (isspace(*b)) {		/* whitespace (or \n) to match? */
	    if (!isspace(*a))		/* no corresponding whitespace? */
		return FALSE;
	    while (len && isspace(*b) && *b != '\n')
		b++,len--;		/* skip pattern whitespace */
	    while (isspace(*a) && *a != '\n')
		a++;			/* skip target whitespace */
	    if (*a == '\n' || *b == '\n')
		return (*a == *b);	/* should end in sync */
	}
	else if (*a++ != *b++)		/* match non-whitespace chars */
	    return FALSE;
	else
	    len--;			/* probably not necessary */
    }
    return TRUE;			/* actually, this is not reached */
					/* since there is always a \n */
}

/* Exit with cleanup. */

void
my_exit(status)
int status;
{
    Unlink(TMPINNAME);
    if (!toutkeep) {
	Unlink(TMPOUTNAME);
    }
    if (!trejkeep) {
	Unlink(TMPREJNAME);
    }
    Unlink(TMPPATNAME);
#ifdef SMALL
    Unlink(TMPSTRNAME);
#endif
    exit(status);
}