syntax.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/* check to turn off a keyword */
    if (keyword) {
	struct key_word *k;
	k = edit->rules[context]->keyword[keyword];
	if (c2 == '\n')
	    keyword = 0;
	if ((k->first == c2 && compare_word_to_right (edit, i + 1, k->keyword, k->whole_word_chars_right, k->whole_word_chars_left, k->line_start)) || (c2 == '\n')) {
	    keyword = 0;
	    keyword_foundright = 1;
	    debug_printf ("keyword=%d ", keyword);
	}
    }
    debug_printf ("border=%s ", border ? ((border & RULE_ON_RIGHT_BORDER) ? "right" : "left") : "off");

/* check to turn off a context */
    if (context && !keyword) {
	r = edit->rules[context];
	if (r->last_left == c1 && compare_word_to_left (edit, i, r->left, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_left) \
	    &&!(rule & RULE_ON_LEFT_BORDER)) {
	    debug_printf ("A:2 ", 0);
	    found_left = 1;
	    border = RULE_ON_LEFT_BORDER;
	    if (r->between_delimiters)
		context = 0;
	} else if (!found_right) {
	    if (r->first_left == c2 && compare_word_to_right (edit, i + 1, r->left, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_left) \
		&&(rule & RULE_ON_LEFT_BORDER)) {
/* always turn off a context at 4 */
		debug_printf ("A:1 ", 0);
		found_right = 1;
		border = 0;
		if (!keyword_foundright)
		    context = 0;
	    } else if (r->first_right == c2 && compare_word_to_right (edit, i + 1, r->right, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_right) \
		       &&(rule & RULE_ON_RIGHT_BORDER)) {
/* never turn off a context at 2 */
		debug_printf ("A:3 ", 0);
		found_right = 1;
		border = 0;
	    }
	}
    }
    debug_printf ("\n", 0);

/* check to turn on a keyword */
    if (!keyword) {
	char *p;
	p = (r = edit->rules[context])->keyword_last_chars;
	while ((p = strchr (p + 1, c1))) {
	    struct key_word *k;
	    int count;
	    count = (unsigned long) p - (unsigned long) r->keyword_last_chars;
	    k = r->keyword[count];
	    if (compare_word_to_left (edit, i, k->keyword, k->whole_word_chars_right, k->whole_word_chars_left, k->line_start)) {
		keyword = count;
		debug_printf ("keyword=%d ", keyword);
		break;
	    }
	}
    }
/* check to turn on a context */
    if (!context) {
	int count;
	for (count = 1; edit->rules[count] && !done; count++) {
	    r = edit->rules[count];
	    if (!found_right) {
		if (r->first_left == c2 && compare_word_to_right (edit, i + 1, r->left, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_left) \
		    &&(rule & RULE_ON_LEFT_BORDER)) {
		    debug_printf ("B:1 count=%d", count);
		    found_right = 1;
		    border = 0;
		    context = 0;
		    contextchanged = 1;
		    keyword = 0;
		} else if (r->first_right == c2 && compare_word_to_right (edit, i + 1, r->right, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_right) \
			   &&(rule & RULE_ON_RIGHT_BORDER)) {
		    if (!(c2 == '\n' && r->single_char)) {
			debug_printf ("B:3 ", 0);
			found_right = 1;
			border = 0;
			if (r->between_delimiters) {
			    debug_printf ("context=%d ", context);
			    context = resolve_left_delim (edit, i, r, count);
			    contextchanged = 1;
			    keyword = 0;
			    if (r->last_left == c1 && compare_word_to_left (edit, i, r->left, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_left)) {
				debug_printf ("B:2 ", 0);
				found_left = 1;
				border = RULE_ON_LEFT_BORDER;
				context = 0;
			    }
			}
			break;
		    }
		}
	    }
	    if (!found_left) {
		if (r->last_right == c1 && compare_word_to_left (edit, i, r->right, r->whole_word_chars_right, r->whole_word_chars_left, r->line_start_right)) {
		    if (!(c1 == '\n' && r->single_char)) {
			debug_printf ("B:4 ", 0);
			found_left = 1;
			border = RULE_ON_RIGHT_BORDER;
			if (!keyword)
			    if (!r->between_delimiters)
				context = resolve_left_delim (edit, i - 1, r, count);
			break;
		    }
		}
	    }
	}
    }
    if (!keyword && contextchanged) {
	char *p;
	p = (r = edit->rules[context])->keyword_last_chars;
	while ((p = strchr (p + 1, c1))) {
	    struct key_word *k;
	    int coutner;
	    coutner = (unsigned long) p - (unsigned long) r->keyword_last_chars;
	    k = r->keyword[coutner];
	    if (compare_word_to_left (edit, i, k->keyword, k->whole_word_chars_right, k->whole_word_chars_left, k->line_start)) {
		keyword = coutner;
		debug_printf ("keyword=%d ", keyword);
		break;
	    }
	}
    }
    debug_printf ("border=%s ", border ? ((border & RULE_ON_RIGHT_BORDER) ? "right" : "left") : "off");
    debug_printf ("keyword=%d ", keyword);

    debug_printf (" %d#\n\n", context);

    return (context << RULE_CONTEXT_SHIFT) | (keyword << RULE_WORD_SHIFT) | border;
}


static unsigned long edit_get_rule (WEdit * edit, long byte_index)
{
    long i;
    if (byte_index < 0) {
	edit->last_get_rule = -1;
	edit->rule = 0;
	return 0;
    }
#if 0
    if (byte_index < edit->last_get_rule_start_display) {
/* this is for optimisation */
	for (i = edit->last_get_rule_start_display - 1; i >= byte_index; i--)
	    edit->rule_start_display = apply_rules_going_left (edit, i, edit->rule_start_display);
	edit->last_get_rule_start_display = byte_index;
	edit->rule = edit->rule_start_display;
    } else
#endif
    if (byte_index > edit->last_get_rule) {
	for (i = edit->last_get_rule + 1; i <= byte_index; i++)
	    edit->rule = apply_rules_going_right (edit, i, edit->rule);
    } else if (byte_index < edit->last_get_rule) {
	for (i = edit->last_get_rule - 1; i >= byte_index; i--)
	    edit->rule = apply_rules_going_left (edit, i, edit->rule);
    }
    edit->last_get_rule = byte_index;
    return edit->rule;
}

static void translate_rule_to_color (WEdit * edit, unsigned long rule, int *fg, int *bg)
{
    struct key_word *k;
    k = edit->rules[(rule & RULE_CONTEXT) >> RULE_CONTEXT_SHIFT]->keyword[(rule & RULE_WORD) >> RULE_WORD_SHIFT];
    *bg = k->bg;
    *fg = k->fg;
}

void edit_get_syntax_color (WEdit * edit, long byte_index, int *fg, int *bg)
{
    unsigned long rule;
    if (!edit->rules || byte_index >= edit->last_byte || !option_syntax_highlighting) {
#ifdef MIDNIGHT
	*fg = NORMAL_COLOR;
#else
	*fg = NO_COLOR;
	*bg = NO_COLOR;
#endif
    } else {
	rule = edit_get_rule (edit, byte_index);
	translate_rule_to_color (edit, rule, fg, bg);
    }
}


/*
   Returns 0 on error/eof or a count of the number of bytes read
   including the newline. Result must be free'd.
 */
static int read_one_line (char **line, FILE * f)
{
    char *p;
    int len = 256, c, r = 0, i = 0;
    p = syntax_malloc (len);
    for (;;) {
	c = fgetc (f);
	if (c == -1) {
	    r = 0;
	    break;
	} else if (c == '\n') {
	    r = i + 1;		/* extra 1 for the newline just read */
	    break;
	} else {
	    if (i >= len - 1) {
		char *q;
		q = syntax_malloc (len * 2);
		memcpy (q, p, len);
		syntax_free (p);
		p = q;
		len *= 2;
	    }
	    p[i++] = c;
	}
    }
    p[i] = 0;
    *line = p;
    return r;
}

static char *strdup_convert (char *s)
{
#if 0
    int e = 0;
#endif
    char *r, *p;
    p = r = strdup (s);
    while (*s) {
	switch (*s) {
	case '\\':
	    s++;
	    switch (*s) {
	    case 'n':
		*p = '\n';
		break;
	    case 'r':
		*p = '\r';
		break;
	    case 't':
		*p = '\t';
		break;
	    case 's':
		*p = ' ';
		break;
	    case '*':
		*p = '*';
		break;
	    case '\\':
		*p = '\\';
		break;
	    case '[':
	    case ']':
		if ((unsigned long) p == (unsigned long) r || strlen (s) == 1)
		    *p = *s;
		else {
#if 0
		    if (!strncmp (s, "[^", 2)) {
			*p = '\004';
			e = 1;
			s++;
		    } else {
			if (e)
			    *p = '\004';
			else
#endif
			    *p = '\003';
#if 0
			e = 0;
		    }
#endif
		}
		break;
	    default:
		*p = *s;
		break;
	    }
	    break;
	case '*':
/* a * or + at the beginning or end of the line must be interpreted literally */
	    if ((unsigned long) p == (unsigned long) r || strlen (s) == 1)
		*p = '*';
	    else
		*p = '\001';
	    break;
	case '+':
	    if ((unsigned long) p == (unsigned long) r || strlen (s) == 1)
		*p = '+';
	    else
		*p = '\002';
	    break;
	default:
	    *p = *s;
	    break;
	}
	s++;
	p++;
    }
    *p = 0;
    return r;
}

#define whiteness(x) ((x) == '\t' || (x) == '\n' || (x) == ' ')

static void get_args (char *l, char **args, int *argc)
{
    *argc = 0;
    l--;
    for (;;) {
	char *p;
	for (p = l + 1; *p && whiteness (*p); p++);
	if (!*p)
	    break;
	for (l = p + 1; *l && !whiteness (*l); l++);
	*l = '\0';
	*args = strdup_convert (p);
	(*argc)++;
	args++;
    }
    *args = 0;
}

static void free_args (char **args)
{
    while (*args) {
	syntax_free (*args);
	*args = 0;
	args++;
    }
}

#define check_a {if(!*a){result=line;break;}}
#define check_not_a {if(*a){result=line;break;}}

#ifdef MIDNIGHT

int try_alloc_color_pair (char *fg, char *bg);

int this_try_alloc_color_pair (char *fg, char *bg)
{
    char f[80], b[80], *p;
    if (fg) {
	strcpy (f, fg);
	p = strchr (f, '/');
	if (p)
	    *p = '\0';
	fg = f;
    }
    if (bg) {
	strcpy (b, bg);
	p = strchr (b, '/');
	if (p)
	    *p = '\0';
	bg = b;
    }
    return try_alloc_color_pair (fg, bg);
}
#else
int this_allocate_color (char *fg)
{
    char *p;
    if (!fg)
	return allocate_color (0);
    p = strchr (fg, '/');
    if (!p)
	return allocate_color (fg);
    return allocate_color (p + 1);
}
#endif

/* returns line number on error */
static int edit_read_syntax_rules (WEdit * edit, FILE * f)
{
    char *fg, *bg;
    char whole_right[256];
    char whole_left[256];
    char *args[1024], *l = 0;
    int line = 0;
    struct context_rule **r, *c;
    int num_words = -1, num_contexts = -1;
    int argc, result = 0;
    int i, j;

    args[0] = 0;

    strcpy (whole_left, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_01234567890");
    strcpy (whole_right, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_01234567890");

    r = edit->rules = syntax_malloc (256 * sizeof (struct context_rule *));

    for (;;) {
	char **a;
	line++;
	if (!read_one_line (&l, f))
	    break;
	get_args (l, args, &argc);
	a = args + 1;
	if (!args[0]) {
	    /* do nothing */
	} else if (!strcmp (args[0], "wholechars")) {
	    check_a;
	    if (!strcmp (*a, "left")) {
		a++;
		strcpy (whole_left, *a);
	    } else if (!strcmp (*a, "right")) {
		a++;
		strcpy (whole_right, *a);
	    } else {
		strcpy (whole_left, *a);
		strcpy (whole_right, *a);
	    }
	    a++;
	    check_not_a;
	} else if (!strcmp (args[0], "context")) {
	    check_a;
	    if (num_contexts == -1) {
		if (strcmp (*a, "default")) {	/* first context is the default */
		    *a = 0;
		    check_a;
		}
		a++;
		c = r[0] = syntax_malloc (sizeof (struct context_rule));
		c->left = strdup (" ");
		c->right = strdup (" ");
		num_contexts = 0;
	    } else {
		c = r[num_contexts] = syntax_malloc (sizeof (struct context_rule));
		if (!strcmp (*a, "exclusive")) {