pch.c

minix软件源代码

/* $Header: pch.c,v 2.0.1.7 88/06/03 15:13:28 lwall Locked $
 *
 * $Log:	pch.c,v $
 * Revision 2.0.1.7  88/06/03  15:13:28  lwall
 * patch10: Can now find patches in shar scripts.
 * patch10: Hunks that swapped and then swapped back could core dump.
 * 
 * Revision 2.0.1.6  87/06/04  16:18:13  lwall
 * pch_swap didn't swap p_bfake and p_efake.
 * 
 * Revision 2.0.1.5  87/01/30  22:47:42  lwall
 * Improved responses to mangled patches.
 * 
 * Revision 2.0.1.4  87/01/05  16:59:53  lwall
 * New-style context diffs caused double call to free().
 * 
 * Revision 2.0.1.3  86/11/14  10:08:33  lwall
 * Fixed problem where a long pattern wouldn't grow the hunk.
 * Also restored p_input_line when backtracking so error messages are right.
 * 
 * Revision 2.0.1.2  86/11/03  17:49:52  lwall
 * New-style delete triggers spurious assertion error.
 * 
 * Revision 2.0.1.1  86/10/29  15:52:08  lwall
 * Could falsely report new-style context diff.
 * 
 * Revision 2.0  86/09/17  15:39:37  lwall
 * Baseline for netwide release.
 * 
 */

#include "EXTERN.h"
#include "common.h"
#include "util.h"
#include "INTERN.h"
#include "pch.h"

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

static long 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_context = 3;		/* # of context lines */
static LINENUM p_input_line = 0;	/* current line # from patch file */
#ifdef SMALL
static long *p_line = Null(long *);	/* the text of the hunk */
#else
static char **p_line = Null(char**);	/* the text of the hunk */
#endif
static short *p_len = Null(short*);	/* length of each line */
static char *p_char = Nullch;		/* +, -, and ! */
static int hunkmax = INITHUNKMAX;	/* size of above arrays to begin with */
static int p_indent;			/* indent to patch */
static LINENUM p_base;			/* where to intuit this time */
static LINENUM p_bline;			/* line # of p_base */
static LINENUM 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 */

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

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

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

void
open_patch_file(filename)
char *filename;
{
    if (filename == Nullch || !*filename || strEQ(filename, "-")) {
	pfp = fopen(TMPPATNAME, "w");
	if (pfp == Nullfp)
	    fatal2("patch: can't create %s.\n", TMPPATNAME);
	while (fgets(buf, sizeof buf, stdin) != Nullch)
	    fputs(buf, pfp);
	Fclose(pfp);
	filename = TMPPATNAME;
    }
    pfp = fopen(filename, "r");
    if (pfp == Nullfp)
	fatal2("patch file %s not found\n", filename);
    Fstat(fileno(pfp), &filestat);
    p_filesize = filestat.st_size;
    next_intuit_at(0L,1L);			/* start at the beginning */
    set_hunkmax();
}

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

void
set_hunkmax()
{
#ifndef lint
#ifdef SMALL
    if (p_line == Null(long*))
#else
    if (p_line == Null(char**))
#endif
#ifdef SMALL
	p_line = (long *) malloc((MEM)hunkmax * sizeof(long));
#else
	p_line = (char**) malloc((MEM)hunkmax * sizeof(char *));
#endif
    if (p_len == Null(short*))
	p_len  = (short*) malloc((MEM)hunkmax * sizeof(short));
#endif
    if (p_char == Nullch)
	p_char = (char*)  malloc((MEM)hunkmax * sizeof(char));
}

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

void
grow_hunkmax()
{
    hunkmax *= 2;
    /* 
     * Note that on most systems, only the p_line array ever gets fresh memory
     * since p_len can move into p_line's old space, and p_char can move into
     * p_len's old space.  Not on PDP-11's however.  But it doesn't matter.
     */
#ifdef SMALL
    assert(p_line != Null(long*) && p_len != Null(short*) && p_char != Nullch);
#else
    assert(p_line != Null(char**) && p_len != Null(short*) && p_char != Nullch);
#endif
#ifndef lint
#ifdef SMALL
    p_line = (long*) realloc((char*)p_line, (MEM)hunkmax * sizeof(long));
#else
    p_line = (char**) realloc((char*)p_line, (MEM)hunkmax * sizeof(char *));
#endif
    p_len  = (short*) realloc((char*)p_len,  (MEM)hunkmax * sizeof(short));
    p_char = (char*)  realloc((char*)p_char, (MEM)hunkmax * sizeof(char));
#endif
#ifdef SMALL
    if (p_line != Null(long*) && p_len != Null(short*) && p_char != Nullch)
#else
    if (p_line != Null(char**) && p_len != Null(short*) && p_char != Nullch)
#endif
	return;
    if (!using_plan_a)
	fatal1("patch: out of memory (grow_hunkmax)\n");
    out_of_mem = TRUE;		/* whatever is null will be allocated again */
				/* from within plan_a(), of all places */
}

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

bool
there_is_another_patch()
{
    if (p_base != 0L && p_base >= p_filesize) {
	if (verbose)
	    say1("done\n");
	return FALSE;
    }
    if (verbose)
	say1("Hmm...");
    diff_type = intuit_diff_type();
    if (!diff_type) {
	if (p_base != 0L) {
	    if (verbose)
		say1("  Ignoring the trailing garbage.\ndone\n");
	}
	else
	    say1("  I can't seem to find a patch in there anywhere.\n");
	return FALSE;
    }
    if (verbose)
	say3("  %sooks like %s to me...\n",
	    (p_base == 0L ? "L" : "The next patch l"),
	    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 (p_indent && verbose)
	say3("(Patch is indented %d space%s.)\n", p_indent, p_indent==1?"":"s");
    skip_to(p_start,p_sline);
    while (filearg[0] == Nullch) {
	if (force) {
	    say1("No file to patch.  Skipping...\n");
	    filearg[0] = savestr(bestguess);
	    return TRUE;
	}
	ask1("File to patch: ");
	if (*buf != '\n') {
	    if (bestguess)
		free(bestguess);
	    bestguess = savestr(buf);
	    filearg[0] = fetchname(buf, 0, FALSE);
	}
	if (filearg[0] == Nullch) {
	    ask1("No file found--skip this patch? [n] ");
	    if (*buf != 'y') {
		continue;
	    }
	    if (verbose)
		say1("Skipping patch...\n");
	    filearg[0] = fetchname(bestguess, 0, TRUE);
	    skip_rest_of_patch = TRUE;
	    return TRUE;
	}
    }
    return TRUE;
}

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

int
intuit_diff_type()
{
    Reg4 long this_line = 0;
    Reg5 long previous_line;
    Reg6 long first_command_line = -1;
    long fcl_line;
    Reg7 bool last_line_was_command = FALSE;
    Reg8 bool this_is_a_command = FALSE;
    Reg9 bool stars_last_line = FALSE;
    Reg10 bool stars_this_line = FALSE;
    Reg3 int indent;
    Reg1 char *s;
    Reg2 char *t;
    char *indtmp = Nullch;
    char *oldtmp = Nullch;
    char *newtmp = Nullch;
    char *indname = Nullch;
    char *oldname = Nullch;
    char *newname = Nullch;
    Reg11 int retval;
    bool no_filearg = (filearg[0] == Nullch);

    ok_to_create_file = FALSE;
    Fseek(pfp, p_base, 0);
    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 = ftell(pfp);
	indent = 0;
	p_input_line++;
	if (fgets(buf, sizeof buf, pfp) == Nullch) {
	    if (first_command_line >= 0L) {
					/* 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;
		retval = 0;
		goto scan_exit;
	    }
	}
	for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
	    if (*s == '\t')
		indent += 8 - (indent % 8);
	    else
		indent++;
	}
	for (t=s; isdigit(*t) || *t == ','; t++) ; 
	this_is_a_command = (isdigit(*s) &&
	  (*t == 'd' || *t == 'c' || *t == 'a') );
	if (first_command_line < 0L && 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))
	    oldtmp = savestr(s+4);
	else if (strnEQ(s, "--- ", 4))
	    newtmp = savestr(s+4);
	else if (strnEQ(s, "Index:", 6))
	    indtmp = savestr(s+6);
	else if (strnEQ(s, "Prereq:", 7)) {
	    for (t=s+7; isspace(*t); t++) ;
	    revision = savestr(t);
	    for (t=revision; *t && !isspace(*t); t++) ;
	    *t = '\0';
	    if (!*revision) {
		free(revision);
		revision = Nullch;
	    }
	}
	if ((!diff_type || diff_type == ED_DIFF) &&
	  first_command_line >= 0L &&
	  strEQ(s, ".\n") ) {
	    p_indent = indent;
	    p_start = first_command_line;
	    p_sline = fcl_line;
	    retval = ED_DIFF;
	    goto scan_exit;
	}
	stars_this_line = strnEQ(s, "********", 8);
	if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
		 strnEQ(s, "*** ", 4)) {
	    if (!atol(s+4))
		ok_to_create_file = TRUE;
	    /* 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);
	    goto scan_exit;
	}
	if ((!diff_type || 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:
    if (no_filearg) {
	if (indtmp != Nullch)
	    indname = fetchname(indtmp, strippath, ok_to_create_file);
	if (oldtmp != Nullch)
	    oldname = fetchname(oldtmp, strippath, ok_to_create_file);
	if (newtmp != Nullch)
	    newname = fetchname(newtmp, strippath, ok_to_create_file);
	if (oldname && newname) {
	    if (strlen(oldname) < strlen(newname))
		filearg[0] = savestr(oldname);
	    else
		filearg[0] = savestr(newname);
	}
	else if (oldname)
	    filearg[0] = savestr(oldname);
	else if (newname)
	    filearg[0] = savestr(newname);
	else if (indname)
	    filearg[0] = savestr(indname);
    }
    if (bestguess) {
	free(bestguess);
	bestguess = Nullch;
    }
    if (filearg[0] != Nullch)
	bestguess = savestr(filearg[0]);
    else if (indtmp != Nullch)
	bestguess = fetchname(indtmp, strippath, TRUE);
    else {
	if (oldtmp != Nullch)
	    oldname = fetchname(oldtmp, strippath, TRUE);
	if (newtmp != Nullch)
	    newname = fetchname(newtmp, strippath, TRUE);
	if (oldname && newname) {
	    if (strlen(oldname) < strlen(newname))
		bestguess = savestr(oldname);
	    else
		bestguess = savestr(newname);
	}
	else if (oldname)
	    bestguess = savestr(oldname);
	else if (newname)
	    bestguess = savestr(newname);
    }
    if (indtmp != Nullch)
	free(indtmp);
    if (oldtmp != Nullch)
	free(oldtmp);
    if (newtmp != Nullch)
	free(newtmp);
    if (indname != Nullch)
	free(indname);
    if (oldname != Nullch)
	free(oldname);
    if (newname != Nullch)
	free(newname);
    return retval;
}

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

void
next_intuit_at(file_pos,file_line)
long file_pos;
long file_line;
{
    p_base = file_pos;
    p_bline = file_line;
}

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

void
skip_to(file_pos,file_line)
long file_pos;
long file_line;
{
    char *ret;

    assert(p_base <= file_pos);
    if (verbose && p_base < file_pos) {
	Fseek(pfp, p_base, 0);
	say1("The text leading up to this was:\n--------------------------\n");
	while (ftell(pfp) < file_pos) {
	    ret = fgets(buf, sizeof buf, pfp);
	    assert(ret != Nullch);
	    say2("|%s", buf);
	}
	say1("--------------------------\n");
    }
    else
	Fseek(pfp, file_pos, 0);
    p_input_line = file_line - 1;
}

/* True if there is more of the current diff listing to process. */