stabstring.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

	enterblock(s);
    }
    if (class != MODULE) {
        s->symvalue.funcv.src = true;
    }
    curparam = s;
}

/*
 * Handling an external variable is tricky, since we might already
 * know it but need to define it's type for other type information
 * in the file.  So just in case we read the type information anyway.
 */

private extVar (symp, n, off)
Symbol *symp;
Name n;
integer off;
{
    Symbol s, t;

    find(s, n) where
	s->level == program->level and s->class == VAR
    endfind(s);
    if (s == nil) {
	makeVariable(s, n, off);
	s->level = program->level;
	s->block = curmodule;
	getExtRef(s);
    } else {
	t = constype(nil);
    }
    *symp = s;
}

/*
 * Check to see if the stab string contains the name of the external
 * reference.  If so, we create a symbol with that name and class EXTREF, and
 * connect it to the given symbol.  This link is created so that when
 * we see the linker symbol we can resolve it to the given symbol.
 */

private getExtRef (s)
Symbol s;
{
    char *p;
    Name n;
    Symbol t;

    if (*curchar == ',' and *(curchar + 1) != '\0') {
	p = index(curchar + 1, ',');
	*curchar = '\0';
	if (p != nil) {
	    *p = '\0';
	    n = identname(curchar + 1, false);
	    curchar = p + 1;
	} else {
	    n = identname(curchar + 1, true);
	}
	t = insert(n);
	t->language = s->language;
	t->class = EXTREF;
	t->block = program;
	t->level = program->level;
	t->symvalue.extref = s;
    }
}

/*
 * Find a block with the given identifier in the given outer block.
 * If not there, then create it.
 */

private Symbol findBlock (id, m)
String id;
Symbol m;
{
    Name n;
    Symbol s;

    n = identname(id, true);
    find(s, n) where s->block == m and isblock(s) endfind(s);
    if (s == nil) {
	s = insert(n);
	s->block = m;
	s->language = curlang;
	s->class = MODULE;
	s->level = m->level + 1;
    }
    return s;
}

/*
 * Enter a nested block.
 * The block within which it is nested is described
 * by "module{:module}[:proc]".
 */

private enterNestedBlock (b)
Symbol b;
{
    register char *p, *q;
    Symbol m, s;
    Name n;

    q = curchar;
    p = index(q, ':');
    m = program;
    while (p != nil) {
	*p = '\0';
	m = findBlock(q, m);
	q = p + 1;
	p = index(q, ':');
    }
    if (*q != '\0') {
	m = findBlock(q, m);
    }
    b->level = m->level + 1;
    b->block = m;
    pushBlock(b);
}

/*
 * Enter a statically-allocated variable defined within a routine.
 *
 * Global BSS variables are chained together so we can resolve them
 * when the start of common is determined.  The list is kept in order
 * so that f77 can display all vars in a COMMON.
 */

private ownVariable (s, addr)
Symbol s;
Address addr;
{
    s->level = 1;
    if (curcomm) {
	if (commchain != nil) {
	    commchain->symvalue.common.chain = s;
	} else {
	    curcomm->symvalue.common.offset = (integer) s;
	}			  
	commchain = s;
	s->symvalue.common.offset = addr;
	s->symvalue.common.chain = nil;
    }
}

/*
 * Get a type from the current stab string for the given symbol.
 */

private getType (s)
Symbol s;
{
    s->type = constype(nil);
    if (s->class == TAG) {
	addtag(s);
    }
}

/*
 * Construct a type out of a string encoding.
 *
 * The forms of the string are
 *
 *	<number>
 *	<number>=<type>
 *	r<type>;<number>;<number>		-- subrange
 *	a<type>;<type>				-- array[index] of element
 *      A<type>					-- open array
 *	s<size>{<name>:<type>;<number>;<number>}-- record
 *	u<size>{<name>:<type>;<number>;<number>}-- union
 *	*<type>					-- pointer
 *	f<type>,<integer>;<paramlist>		-- function variable
 *	p<integer>;<paramlist>			-- procedure variable
 *	S<type>					-- set of type
 *	o<name>[,<type>]			-- opaque type
 *	i<name>,<type>				-- imported type
 */

private Rangetype getRangeBoundType();

private Symbol constype (type)
Symbol type;
{
    register Symbol t;
    register integer n;
    char class;
    char *p;

    while (*curchar == '@') {
	p = index(curchar, ';');
	if (p == nil) {
	    fflush(stdout);
	    fprintf(stderr, "missing ';' after type attributes");
	} else {
	    curchar = p + 1;
	}
    }
    if (isdigit(*curchar)) {
	n = getint();
	if (n >= NTYPES) {
	    panic("too many types in file \"%s\"", curfilename());
	}
	if (*curchar == '=') {
	    if (typetable[n] != nil) {
		t = typetable[n];
	    } else {
		t = symbol_alloc();
		typetable[n] = t;
	    }
	    ++curchar;
	    constype(t);
	} else {
	    t = typetable[n];
	    if (t == nil) {
		t = symbol_alloc();
		typetable[n] = t;
	    }
	}
    } else {
	if (type == nil) {
	    t = symbol_alloc();
	} else {
	    t = type;
	}
	t->language = curlang;
	t->level = curblock->level + 1;
	t->block = curblock;
	class = *curchar++;
	switch (class) {
	    case T_SUBRANGE:
		consSubrange(t);
		break;

	    case T_ARRAY:
		t->class = ARRAY;
		t->chain = constype(nil);
		skipchar(curchar, ';');
		chkcont(curchar);
		t->type = constype(nil);
		break;

	    case T_OLDOPENARRAY:
		t->class = DYNARRAY;
		t->symvalue.ndims = 1;
		t->type = constype(nil);
		t->chain = t_int;
		break;

	    case T_OPENARRAY:
	    case T_DYNARRAY:
		consDynarray(t);
		break;

	    case T_SUBARRAY:
		t->class = SUBARRAY;
		t->symvalue.ndims = getint();
		skipchar(curchar, ',');
		t->type = constype(nil);
		t->chain = t_int;
		break;

	    case T_RECORD:
		consRecord(t, RECORD);
		break;

	    case T_UNION:
		consRecord(t, VARNT);
		break;

	    case T_ENUM:
		consEnum(t);
		break;

	    case T_PTR:
		t->class = PTR;
		t->type = constype(nil);
		break;

	    /*
	     * C function variables are different from Modula-2's.
	     */
	    case T_FUNCVAR:
		t->class = FFUNC;
		t->type = constype(nil);
		if (curlang != findlanguage(C)) {
		    skipchar(curchar, ',');
		    consParamlist(t);
		}
		break;

	    case T_PROCVAR:
		t->class = FPROC;
		consParamlist(t);
		break;

	    case T_IMPORTED:
		consImpType(t);
		break;

	    case T_SET:
		t->class = SET;
		t->type = constype(nil);
		break;

	    case T_OPAQUE:
		consOpaqType(t);
		break;

	    case T_FILE:
		t->class = FILET;
		t->type = constype(nil);
		break;

	    default:
		badcaseval(class);
	}
    }
    return t;
}

/*
 * Construct a subrange type.
 */

private consSubrange (t)
Symbol t;
{
    t->class = RANGE;
    t->type = constype(nil);
    skipchar(curchar, ';');
    chkcont(curchar);
    t->symvalue.rangev.lowertype = getRangeBoundType();
    t->symvalue.rangev.lower = getint();
    skipchar(curchar, ';');
    chkcont(curchar);
    t->symvalue.rangev.uppertype = getRangeBoundType();
    t->symvalue.rangev.upper = getint();
}

/*
 * Figure out the bound type of a range.
 *
 * Some letters indicate a dynamic bound, ie what follows
 * is the offset from the fp which contains the bound; this will
 * need a different encoding when pc a['A'..'Z'] is
 * added; J is a special flag to handle fortran a(*) bounds
 */

private Rangetype getRangeBoundType ()
{
    Rangetype r;

    switch (*curchar) {
	case 'A':
	    r = R_ARG;
	    curchar++;
	    break;

	case 'T':
	    r = R_TEMP;
	    curchar++;
	    break;

	case 'J': 
	    r = R_ADJUST;
	    curchar++;
	    break;

	default:
	    r = R_CONST;
	    break;
    }
    return r;
}

/*
 * Construct a dynamic array descriptor.
 */

private consDynarray (t)
register Symbol t;
{
    t->class = DYNARRAY;
    t->symvalue.ndims = getint();
    skipchar(curchar, ',');
    t->type = constype(nil);
    t->chain = t_int;
}

/*
 * Construct a record or union type.
 */

private consRecord (t, class)
Symbol t;
Symclass class;
{
    register Symbol u;
    register char *cur, *p;
    Name name;
    integer d;

    t->class = class;
    t->symvalue.offset = getint();
    d = curblock->level + 1;
    u = t;
    cur = curchar;
    while (*cur != ';' and *cur != '\0') {
	p = index(cur, ':');
	if (p == nil) {
	    panic("index(\"%s\", ':') failed", curchar);
	}
	*p = '\0';
	name = identname(cur, true);
	u->chain = newSymbol(name, d, FIELD, nil, nil);
	cur = p + 1;
	u = u->chain;
	u->language = curlang;
	curchar = cur;
	u->type = constype(nil);
	skipchar(curchar, ',');
	u->symvalue.field.offset = getint();
	skipchar(curchar, ',');
	u->symvalue.field.length = getint();
	skipchar(curchar, ';');
	chkcont(curchar);
	cur = curchar;
    }
    if (*cur == ';') {
	++cur;
    }
    curchar = cur;
}

/*
 * Construct an enumeration type.
 */

private consEnum (t)
Symbol t;
{
    register Symbol u;
    register char *p;
    register integer count;

    t->class = SCAL;
    count = 0;
    u = t;
    while (*curchar != ';' and *curchar != '\0') {
	p = index(curchar, ':');
	assert(p != nil);
	*p = '\0';
	u->chain = insert(identname(curchar, true));
	curchar = p + 1;
	u = u->chain;
	u->language = curlang;
	u->class = CONST;
	u->level = curblock->level + 1;
	u->block = curblock;
	u->type = t;
	u->symvalue.constval = build(O_LCON, (long) getint());
	++count;
	skipchar(curchar, ',');
	chkcont(curchar);
    }
    if (*curchar == ';') {
	++curchar;
    }
    t->symvalue.iconval = count;
}

/*
 * Construct a parameter list for a function or procedure variable.
 */

private consParamlist (t)
Symbol t;
{
    Symbol p;
    integer i, d, n, paramclass;

    n = getint();
    skipchar(curchar, ';');
    p = t;
    d = curblock->level + 1;
    for (i = 0; i < n; i++) {
	p->chain = newSymbol(nil, d, VAR, nil, nil);
	p = p->chain;
	p->type = constype(nil);
	skipchar(curchar, ',');
	paramclass = getint();
	if (paramclass == 0) {
	    p->class = REF;
	}
	skipchar(curchar, ';');
	chkcont(curchar);
    }
}

/*
 * Construct an imported type.
 * Add it to a list of symbols to get fixed up.
 */

private consImpType (t)
Symbol t;
{
    register char *p;
    Symbol tmp;

    p = curchar;
    while (*p != ',' and *p != ';' and *p != '\0') {
	++p;
    }
    if (*p == '\0') {
	panic("bad import symbol entry '%s'", curchar);
    }
    t->class = TYPEREF;
    t->symvalue.typeref = curchar;
    if (*p == ',') {
	curchar = p + 1;
	tmp = constype(nil);
    } else {
	curchar = p;
    }
    skipchar(curchar, ';');
    *p = '\0';
}

/*
 * Construct an opaque type entry.
 */

private consOpaqType (t)
Symbol t;
{
    register char *p;
    register Symbol s;
    register Name n;
    boolean def;

    p = curchar;
    while (*p != ';' and *p != ',') {
	if (*p == '\0') {
	    panic("bad opaque symbol entry '%s'", curchar);
	}
	++p;
    }
    def = (Boolean) (*p == ',');
    *p = '\0';
    n = identname(curchar, true);
    find(s, n) where s->class == TYPEREF endfind(s);
    if (s == nil) {
	s = insert(n);
	s->class = TYPEREF;
	s->type = nil;
    }
    curchar = p + 1;
    if (def) {
	s->type = constype(nil);
	skipchar(curchar, ';');
    }
    t->class = TYPE;
    t->type = s;
}

/*
 * Read an integer from the current position in the type string.
 */

private integer getint ()
{
    register integer n;
    register char *p;
    register Boolean isneg;

    n = 0;
    p = curchar;
    if (*p == '-') {
	isneg = true;
	++p;
    } else {
	isneg = false;
    }
    while (isdigit(*p)) {
	n = 10*n + (*p - '0');
	++p;
    }
    curchar = p;
    return isneg ? (-n) : n;
}

/*
 * Add a tag name.  This is a kludge to be able to refer
 * to tags that have the same name as some other symbol
 * in the same block.
 */

private addtag (s)
register Symbol s;
{
    register Symbol t;
    char buf[100];

    sprintf(buf, "$$%.90s", ident(s->name));
    t = insert(identname(buf, false));
    t->language = s->language;
    t->class = TAG;
    t->type = s->type;
    t->block = s->block;
}

/* Routine to handle VAX Debug DST types that will not map to a specific
 * stab entry.  Keep the name around, and assign a special class, so that
 * we are able to acknowledge the existence of the symbol (ie, don't
 * give "undefined" error message).  In which() (symbols.c), if one of
 * these is encountered, we print a message saying that symbolic information
 * is not available for the symbol.
 */
public mkdstsym(name)
String name;
{
    Symbol s;
    Name n;

    n = identname(name, true);
    newSym(s, n);
    s->class = NO_DSTMAP;
}