c.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

	    printtype(t, t->type, indent);
	    if (t->type->class != PTR) {
		printf(" ");
	    }
	    printf("*");
	    break;

	case FUNC:
	case FFUNC:
	    printtype(t, t->type, indent);
	    printf("()");
	    break;

	case TYPE:
	    if (t->name != nil) {
		printname(stdout, t);
	    } else {
		printtype(t, t->type, indent);
	    }
	    break;

	case TYPEREF:
	    printf("@%s", symname(t));
	    break;

	case SCAL:
	    printf("enum ");
	    if (s->name != nil and s->class == TAG) {
		printf("%s ", symname(s));
	    }
	    printf("{ ");
	    i = t->chain;
	    if (i != nil) {
		for (;;) {
		    printf("%s", symname(i));
		    i = i->chain;
		if (i == nil) break;
		    printf(", ");
		}
	    }
	    printf(" }");
	    break;

	case TAG:
	    if (t->type == nil) {
		printf("unresolved tag %s", symname(t));
	    } else {
		i = rtype(t->type);
		printf("%s %s", c_classname(i), symname(t));
	    }
	    break;

	default:
	    printf("(class %d)", t->class);
	    break;
    }
}

/*
 * List the parameters of a procedure or function.
 * No attempt is made to combine like types.
 */

public c_listparams(s)
Symbol s;
{
    register Symbol t;

    putchar('(');
    for (t = s->chain; t != nil; t = t->chain) {
	printf("%s", symname(t));
	if (t->chain != nil) {
	    printf(", ");
	}
    }
    putchar(')');
    if (s->chain != nil) {
	printf("\n");
	for (t = s->chain; t != nil; t = t->chain) {
	    if (t->class != VAR) {
		panic("unexpected class %d for parameter", t->class);
	    }
	    printdecl(t, 0);
	}
    } else {
	putchar('\n');
    }
}

/*
 * Print out the value on the top of the expression stack
 * in the format for the type of the given symbol.
 */

public c_printval(s)
Symbol s;
{
    register Symbol t;
    register Address a;
    integer i, len;

    switch (s->class) {
	case CONST:
	case TYPE:
	case VAR:
	case REF:
	case FVAR:
	case TAG:
	    c_printval(s->type);
	    break;

	case FIELD:
	    if (isbitfield(s)) {
		i = 0;
		popn(size(s), &i);
		i >>= (s->symvalue.field.offset mod BITSPERBYTE);
		i &= ((1 << s->symvalue.field.length) - 1);
		t = rtype(s->type);
		if (t->class == SCAL) {
		    printEnum(i, t);
		} else {
		    printRangeVal(i, t);
		}
	    } else {
		c_printval(s->type);
	    }
	    break;

	case ARRAY:
	    t = rtype(s->type);
	    if ((t->class == RANGE and istypename(t->type, "char")) or
		t == t_char->type
	    ) {
		len = size(s);
		sp -= len;
		if (s->language == primlang) {
		    printf("%.*s", len, sp);
		} else {
		    printf("\"%.*s\"", len, sp);
		}
	    } else {
		printarray(s);
	    }
	    break;

	case RECORD:
	    c_printstruct(s);
	    break;

	case RANGE:
	    if (s == t_boolean->type or istypename(s->type, "boolean")) {
		printRangeVal(popsmall(s), s);
	    } else if (s == t_char->type or istypename(s->type, "char")) {
		printRangeVal(pop(char), s);
	    } else if (s == t_real->type or isdouble(s)) {
		switch (s->symvalue.rangev.lower) {
		    case sizeof(float):
			prtreal(pop(float));
			break;

		    case sizeof(double):
			prtreal(pop(double));
			break;

		    default:
			panic("bad real size %d", t->symvalue.rangev.lower);
			break;
		}
	    } else {
		printRangeVal(popsmall(s), s);
	    }
	    break;

	case PTR:
	    t = rtype(s->type);
	    a = pop(Address);
	    if (a == 0) {
			printf("(nil)");
	    } else  {
			if (t->class == RANGE and istypename(t->type, "char")) {
				printString(a, (boolean) (s->language != primlang));
	    	} else {
				printf("0x%x", a);
	    	}
		}
	    break;

	case SCAL:
	    i = pop(Integer);
	    printEnum(i, s);
	    break;

	/*
	 * Unresolved structure pointers?
	 */
	case BADUSE:
	    a = pop(Address);
	    printf("@%x", a);
	    break;

	default:
	    if (ord(s->class) > ord(TYPEREF)) {
		panic("printval: bad class %d", ord(s->class));
	    }
	    sp -= size(s);
	    printf("[%s]", c_classname(s));
	    break;
    }
}

/*
 * Print out a C structure.
 */

private c_printstruct (s)
Symbol s;
{
    Symbol f;
    Stack *savesp;
    integer n, off, len;

    sp -= size(s);
    savesp = sp;
    printf("(");
    f = s->chain;
    for (;;) {
	off = f->symvalue.field.offset;
	len = f->symvalue.field.length;
	n = (off + len + BITSPERBYTE - 1) div BITSPERBYTE;
	sp += n;
	printf("%s = ", symname(f));
	c_printval(f);
	sp = savesp;
	f = f->chain;
    if (f == nil) break;
	printf(", ");
    }
    printf(")");
}

#define MAXSTRLENGTH 10000
public Node c_printf(p, argv)
Node p;
char **argv;
{
	char str[MAXSTRLENGTH];
	char *fmt;
	va_list ap = (va_list)&argv[1];

	fmt = argv[0];
	if (!fmt) return;
	while (*fmt) {
	    if (strncmp(fmt,"%s",2) == 0)
		error("percent-s format not implemented for printf");
	    fmt++;
	} /* while */
	vsprintf(str, argv[0], ap);
	fputs(str, stdout);
}


/*
 * Return the C name for the particular class of a symbol.
 */

public String c_classname(s)
Symbol s;
{
    String str;

    switch (s->class) {
	case RECORD:
	    str = "struct";
	    break;

	case VARNT:
	    str = "union";
	    break;

	case SCAL:
	    str = "enum";
	    break;

	default:
	    str = classname(s);
    }
    return str;
}

public Node c_buildaref(a, slist)
Node a, slist;
{
    register Symbol t;
    register Node p;
    Symbol etype, atype, eltype;
    Node r, esub;

    t = rtype(a->nodetype);
    eltype = t->type;
    if (t->class == PTR) {
	p = slist->value.arg[0];
	if (not compatible(p->nodetype, t_int)) {
	    beginerrmsg();
	    fprintf(stderr, "subscript must be integer-compatible");
	    enderrmsg();
	}
	r = build(O_MUL, p, build(O_LCON, (long) size(eltype)));
	r = build(O_ADD, build(O_RVAL, a), r);
	r->nodetype = eltype;
    } else if (t->class != ARRAY) {
	beginerrmsg();
	fprintf(stderr, "\"");
	prtree(stderr, a);
	fprintf(stderr, "\" is not an array");
	enderrmsg();
    } else {
	r = a;
	p = slist;
	t = t->chain;
	for (; p != nil and t != nil; p = p->value.arg[1], t = t->chain) {
	    esub = p->value.arg[0];
	    etype = rtype(esub->nodetype);
	    atype = rtype(t);
	    if (not compatible(atype, etype)) {
		beginerrmsg();
		fprintf(stderr, "subscript \"");
		prtree(stderr, esub);
		fprintf(stderr, "\" is the wrong type");
		enderrmsg();
	    }
	    r = build(O_INDEX, r, esub);
	    r->nodetype = eltype;
	}
	if (p != nil or t != nil) {
	    beginerrmsg();
	    if (p != nil) {
		fprintf(stderr, "too many subscripts for \"");
	    } else {
		fprintf(stderr, "not enough subscripts for \"");
	    }
	    prtree(stderr, a);
	    fprintf(stderr, "\"");
	    enderrmsg();
	}
    }
    return r;
}

/*
 * Evaluate a subscript index.
 */

public c_evalaref(s, base, i)
Symbol s;
Address base;
long i;
{
    Symbol t;
    long lb, ub;

    t = rtype(s);
    s = t->chain;
    lb = s->symvalue.rangev.lower;
    ub = s->symvalue.rangev.upper;
    if (i < lb or i > ub) {
	error("subscript out of range");
    }
    push(long, base + (i - lb) * size(t->type));
}

/*
 * Initialize typetable information.
 */

public c_modinit (typetable)
Symbol typetable[];
{
    /* nothing right now */
}

public boolean c_hasmodules ()
{
    return false;
}

public boolean c_passaddr (param, exprtype)
Symbol param, exprtype;
{
    boolean b;
    Symbol t;

    t = rtype(exprtype);
    b = (boolean) (t->class == ARRAY);
    return b;
}