norm.c

c 语言编译器 源代码- c compiler

/* @(#) norm.c 1.3 1/27/86 17:49:14 */ 
/*ident	"@(#)cfront:src/norm.c	1.3" */
/************************************************************************

	C++ source for cfront, the C++ compiler front-end
	written in the computer science research center of Bell Labs

	Copyright (c) 1984 AT&T, Inc. All Rights Reserved
	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T, INC.


norm.c:

	"normalization" handles problems which could have been handled
	by the syntax analyser; but has not been done. The idea is
	to simplify the grammar and the actions accociated with it,
	and to get a more robust error handling

****************************************************************************/

#include "cfront.h"
#include "size.h"

extern void syn_init();
void syn_init()
{
	any_type = new basetype(ANY,0);
	PERM(any_type);
	dummy = new expr(DUMMY,0,0);
	PERM(dummy);
	dummy->tp = any_type;
	zero = new expr(ZERO,0,0);
	PERM(zero);
}


int stcount;

char* make_name(TOK c)
{

	char* s = new char[8];	/* as it happens: fits in two words */


	if (99999 <= ++stcount) error('i',"too many generated names");

	s[0] = '_';
	s[1] = c;
	int count = stcount;
	int i = 2;
	if (10000 <= count) {
		s[i++] = '0' + count/10000;
		count %= 10000;
	}
	if (1000 <= count) {
		s[i++] = '0' + count/1000;
		count %= 1000;
	}
	else if (2<i) s[i++] = '0';

	if (100 <= count) {
		s[i++] = '0' + count/100;
		count %= 100;
	}
	else if (2<i) s[i++] = '0';

	if (10 <= count) {
		s[i++] = '0' + count/10;
		count %= 10;
	}
	else if (2<i) s[i++] = '0';

	s[i++] = '0' + count;
	s[i] = 0;

	return s;
}

Pbase basetype.type_adj(TOK t)
{
	switch (base) {
	case COBJ:
	case EOBJ:
	{	Pbase bt = new basetype(0,0);
		*bt = *this;
		DEL(this);
		this = bt;
	}
	}
			
	if (b_xname) {
		if (base)
			error("badBT:%n%k",b_xname,t);
		else {
			base = TYPE;
			b_name = b_xname;
		}
		b_xname = 0;
	}

	switch (t) {
	case TYPEDEF:	b_typedef = 1;	break;
	case INLINE:	b_inline = 1;	break;
	case VIRTUAL:	b_virtual = 1;	break;
	case CONST:	b_const = 1;	break;
	case UNSIGNED:	b_unsigned = 1;	break;
	case SHORT:	b_short = 1;	break;
	case LONG:	b_long = 1;	break;
	case FRIEND:
	case OVERLOAD:
	case EXTERN:
	case STATIC:
	case AUTO:
	case REGISTER:
		if (b_sto)
			error("badBT:%k%k",b_sto,t);
		else
			b_sto = t;
		break;
	case VOID:
	case CHAR:
	case INT:
	case FLOAT:
	case DOUBLE:
		if (base)
			error("badBT:%k%k",base,t);
		else
			base = t; 
		break;
	default:
		error('i',"basetype.type_adj(%k)",t);
	}
	return this;
}

Pbase basetype.name_adj(Pname n)
{
	if (b_xname) {
		if (base)
			error("badBT:%n%n",b_xname,n);
		else {
			base = TYPE;
			b_name = b_xname;
		}
		b_xname = 0;
	}
	b_xname = n;
	return this;
}

Pbase basetype.base_adj(Pbase b)
{
	Pname bn = b->b_name;

	switch (base) {
	case COBJ:
	case EOBJ:
		error("NX after%k%n",base,b_name);
		return this;
	}

	if (base) {
		if (b_name)
			error("badBT:%k%n%k%n",base,b_name,b->base,bn);
		else
			error("badBT:%k%k%n",base,b->base,bn);
	}
	else {
		base = b->base;
		b_name = bn;
		b_table = b->b_table;
	}
	return this;
}

Pbase basetype.check(Pname n)
/*
	"n" is the first name to be declared using "this"
	check the consistency of "this"
	and use "b_xname" for "n->string" if possible and needed
*/
{
	b_inline = 0;
	b_virtual = 0;
//fprintf(stderr,"check n: %d %s n_oper %d b: %d %d %s\n",n,(n)?n->string:"",n?n->n_oper:0,this,base,(b_name)?b_name->string:"");fflush(stderr);
	if (b_xname && (n->tp || n->string)) {
		if (base)
			error("badBT:%k%n",base,b_xname);
		else {
			base = TYPE;
			b_name = b_xname;
		}
		b_xname = 0;
	}

	if (b_xname) {
		if (n->string)
			error("twoNs inD:%n%n",b_xname,n);
		else {
			n->string = b_xname->string;
			b_xname->hide();
		}
		b_xname = 0;
	}

	if (ccl==0
	&& n
	&& n->n_oper==TNAME
	&& n->n_qualifier==0
	&& n->string) {	// hide type name
		Pname nx = ktbl->look(n->string,0);
		if (nx) nx->hide();
	}

	switch (base) {
	case 0:
		base = INT;
		break;
	case EOBJ:
	case COBJ:
		if (b_name->base == TNAME)
			error('i',"TN%n inCO %d",b_name,this);
	}

	if (b_long || b_short) {
		TOK sl = (b_short) ? SHORT : LONG;
		if (b_long && b_short) error("badBT:long short%k%n",base,n);
		if (base != INT)
			error("badBT:%k%k%n",sl,base,n);
		else
			base = sl;
		b_short = b_long = 0;
	}

	if (b_typedef && b_sto) error("badBT:typedef%k%n",b_sto,n);
	b_typedef = b_sto = 0;

	if (Pfctvec_type == 0) return this;

	if (b_const) {
		if (b_unsigned) {
			switch (base) {
			default:
				error("badBT: unsigned const %k%n",base,n);
				b_unsigned = 0;
			case LONG:
			case SHORT:
			case INT:
			case CHAR:
				return this;
			}
		}
		return this;
	}
	else if (b_unsigned) {
		switch (base) {
		case LONG:
			delete this;
			return ulong_type;
		case SHORT:
			delete this;
			return ushort_type;
		case INT:
			delete this;
			return uint_type;
		case CHAR:
			delete this;
			return uchar_type;
		default:
			error("badBT: unsigned%k%n",base,n);
			b_unsigned = 0;
			return this;
		}
	}
	else {
		switch (base) {
		case LONG:
			delete this;
			return long_type;
		case SHORT:
			delete this;
			return short_type;
		case INT:
			if (this != int_type) delete this;
			return int_type;
		case CHAR:
			delete this;
			return char_type;
		case VOID:
			delete this;
			return void_type;
		case TYPE:
			/* use a single base saved in the keyword */
//fprintf(stderr,"type %d bn %d %s q %d\n",this,b_name,b_name->string,b_name->n_qualifier);
			if (b_name->n_qualifier) {
				delete this;
				return (Pbase)b_name->n_qualifier;
			}
			else {
				PERM(this);
				b_name->n_qualifier = (Pname)this;
				return this;
			}
		default:
			return this;
		}
	}
}

Pname basetype.aggr()
/*
	"type SM" seen e.g.	struct s {};
				class x;
				enum e;
				int tname;
				friend cname;
				friend class x;
				int;

	convert
		union { ... };
	into
		union name { ... } name ;
*/
{
	Pname n;

	if (b_xname) {
		if (base) {
			Pname n = new name(b_xname->string);
			b_xname->hide();
			b_xname = 0;
			return n->normalize(this,0,0);
		}
		else {
			base = TYPE;
			b_name = b_xname;
			b_xname = 0;
		}
	}


	switch (base) {
	case COBJ:
	{	Pclass cl = (Pclass)b_name->tp;
		char* s = cl->string;
/*fprintf(stderr,"COBJ (%d %s) -> (%d %d) ->(%d %d)\n",this,b_name->string,b_name,b_name->base,cl,cl->base);*/
		if (b_name->base == TNAME) error('i',"TN%n inCO",b_name);
		if (b_const) error("const%k%n",cl->csu,b_name);

		if (cl->c_body == 2) {	/* body seen */
			if (s[0]=='_' && s[1]=='C') {
				char* ss = new char[5];
				Pname obj = new name(ss);
				if (cl->csu == UNION) {
					strcpy(ss,s);
					ss[1] = 'O';
					cl->csu = ANON;
					return obj->normalize(this,0,0);
				}
				error('w',"un-usable%k ignored",cl->csu);
			}
			cl->c_body = 1;
			return b_name;
		}
		else {	/* really a typedef for cfront only: class x; */
			if (b_sto == FRIEND) goto frr;
			return 0;
		}
	}

	case EOBJ:
	{	Penum en = (Penum)b_name->tp;
/*fprintf(stderr,"EOBJ (%d %s) -> (%d %d) ->(%d %d)\n",this,b_name->string,b_name,b_name->base,en,en->base);*/
		if (b_name->base == TNAME) error('i',"TN%n in enumO",b_name);
		if (b_const) error("const enum%n",b_name);
		if (en->e_body == 2) {
			en->e_body = 1;
			return b_name;
		}
		else {
			if (b_sto == FRIEND) goto frr;
			return 0;
		}
	}

	default:
		if (b_typedef) error('w',"illegal typedef ignored");

		if (b_sto == FRIEND) {
		frr:
			Pname fr = ktbl->look(b_name->string,0);
			if (fr == 0) error('i',"cannot find friend%n",b_name);
			n = new name(b_name->string);
			n->n_sto = FRIEND;
			n->tp = fr->tp;
			return n;
		}
		else {
			n = new name(make_name('D'));
			n->tp = any_type;
			error('w',"NX inDL");
			return n;
		}
	}
}

void name.hide()
/*
	hide "this": that is, "this" should not be a keyword in this scope
*/
{
//error('d',"hide%n %d %k tp %d",this,this,base,tp);
	if (base != TNAME) return;
	if (n_key == 0) {
//error('d',"ll %d bl %d base %k",lex_level,bl_level,base);
		if (lex_level == bl_level) {
			if (this->base != TNAME)
				error("%n redefined",this);
			else {
				// is it a CN?
				error('w',"%n redefined",this);
			}
		}
		modified_tn = new name_list(this,modified_tn);
		n_key = HIDDEN;
	}
}

void set_scope(Pname tn)
/*
	enter the scope of class tn after seeing "tn.f"
*/
{
	if (tn->base != TNAME) error('i',"set_scope: not aTN %d %d",tn,tn->base);
	Pbase b = (Pbase)tn->tp;
	if (b->b_name->tp->base != CLASS) error('i',"T of%n not aC (%k)",tn,b->b_name->tp->base);
	Pclass cl = (Pclass)b->b_name->tp;
	for (Plist l=cl->tn_list; l; l=l->l) {
		Pname n = l->f;
		n->n_key = (n->lex_level) ? 0 : HIDDEN;
//error('d',"set_scope%n %d",n,n->n_key);
		modified_tn = new name_list(n,modified_tn);
	}
}

void restore()
{
	for (Plist l=modified_tn; l; l=l->l) {
		Pname n = l->f;
		n->n_key =  (n->lex_level <= bl_level) ? 0 : HIDDEN;
//error('d',"restore%n %d",n,n->n_key);
	}
}

Pbase start_cl(TOK t, Pname c, Pname b)
{
	if (c == 0) c = new name(make_name('C'));
//error('d',"c: %d %s",c->base,c->string);
	Pname n = c->tname(t);			/* t ignored */
	n->where = curloc;
	Pbase bt = (Pbase)n->tp;		/* COBJ */
	if (bt->base != COBJ) {
		error("twoDs of%n:%t andC",n,bt);
		error('i', "can't recover from previous errors");
	}
	Pclass occl = ccl;
	ccl = (Pclass)bt->b_name->tp;		/* CLASS */
	if (ccl->defined) {
		error("C%n defined twice");
		ccl->defined |= IN_ERROR;
	}
	ccl->defined |= DEF_SEEN;
	if (ccl->in_class = occl) occl->tn_list = modified_tn;	// save  mod-list
	modified_tn = 0;
	ccl->string = n->string;
	ccl->csu = t;
	if (b) ccl->clbase = b->tname(t);
	return bt;	
}

void end_cl()
{
	Pclass occl = ccl->in_class;
	Plist ol = occl ? occl->tn_list : 0;	// saved modified name list
	ccl->c_body = 2;
	if (modified_tn) {	// export nested class names to outer scope:
		Plist local = 0;
		for (Plist l=modified_tn, nl=0; l; l=nl) {
			nl = l->l;
			Pname n = l->f;
			if (ktbl->look(n->string,0)) {
				// add it to enclosing class's modified name list
				l->l = ol;
				ol = l;
			}
			else {	// retain it in this class's modified name list
				l->l = local;
				local = l;
			}
		}
		if (ccl->tn_list = modified_tn = local) restore();
	}
	modified_tn = ol;	// restore mod-list (possibly modified)
	ccl = occl;
}

Pbase end_enum(Pname n, Pname b)
{
	if (n == 0) n = new name(make_name('E'));
	n = n->tname(ENUM);
	Pbase bt = (Pbase)n->tp;
	if (bt->base != EOBJ) {
		error("twoDs of%n:%t and enum",n,bt);
		error('i', "can't recover from previous errors");
	}
	Penum en = (Penum)bt->b_name->tp;
	en->e_body = 2;
	en->mem = name_unlist((class nlist *)b);
	if (en->defined) {
		error("enum%n defined twice",n);
		en->defined |= IN_ERROR;
	}
	en->defined |= DEF_SEEN;
	return bt;
}

Pname name.tdef()
/*
	typedef "this"
*/
{
//error('d',"tdef%n",this);
	Pname n = ktbl->insert(this,0);
	if (tp == 0) error('i',"typedef%n tp==0",this);
	n->base = base = TNAME;
	PERM(n);
	PERM(tp);
	modified_tn = new name_list(n,modified_tn);
	return n;
}

Pname name.tname(TOK csu)
/*
	"csu" "this" seen, return typedef'd name for "this"
	return	(TNAME,x)
	x:	(COBJ,y)
	y:	(NAME,z)
	z:	(CLASS,ae);
*/
{
//fprintf(stderr,"tname %s %d ll %d\n",string,this,lex_level);
	switch (base) {
	case TNAME:
		return this;
	case NAME:
	{	Pname tn = ktbl->insert(this,0);
//fprintf(stderr,"tname tn %s %d ll %d (mod %d)\n",tn->string,tn,tn->lex_level,modified_tn);
		Pname on = new name;
		tn->base = TNAME;
		tn->lex_level = lex_level;
		modified_tn = new name_list(tn,modified_tn);
		tn->n_list = n_list = 0;
		string = tn->string;
		*on = *this;
		switch (csu) {
		case ENUM:
			tn->tp = new basetype(EOBJ,on);
			on->tp = new enumdef(0);
			break;
		default:
			on->tp =  new classdef(csu,0);
			Pclass(on->tp)->string = tn->string;
			tn->tp = new basetype(COBJ,on);
			Pbase(tn->tp)->b_table = Pclass(on->tp)->memtbl;
		}
		PERM(tn);
		PERM(tn->tp);
		PERM(on);