#include "c.h"static char rcsid[] = "$Id: tree.c,v 1.1 2002/08/28 23:12:47 drh Exp $";int where = STMT;static int warn;static int nid = 1;		/* identifies trees & nodes in debugging output */static struct nodeid {	int printed;	Tree node;} ids[500];			/* if ids[i].node == p, then p's id is i */static void printtree1(Tree, int, int);Tree tree(int op, Type type, Tree left, Tree right) {	Tree p;	NEW0(p, where);	p->op = op;	p->type = type;	p->kids[0] = left;	p->kids[1] = right;	return p;}Tree texpr(Tree (*f)(int), int tok, int a) {	int save = where;	Tree p;	where = a;	p = (*f)(tok);	where = save;	return p;}static Tree root1(Tree p) {	if (p == NULL)		return p;	if (p->type == voidtype)		warn++;	switch (generic(p->op)) {	case COND: {		Tree q = p->kids[1];		assert(q && q->op == RIGHT);		if (p->u.sym && q->kids[0] && generic(q->kids[0]->op) == ASGN)			q->kids[0] = root1(q->kids[0]->kids[1]);		else			q->kids[0] = root1(q->kids[0]);		if (p->u.sym && q->kids[1] && generic(q->kids[1]->op) == ASGN)			q->kids[1] = root1(q->kids[1]->kids[1]);		else			q->kids[1] = root1(q->kids[1]);		p->u.sym = 0;		if (q->kids[0] == 0 && q->kids[1] == 0)			p = root1(p->kids[0]);		}		break;	case AND: case OR:		if ((p->kids[1] = root1(p->kids[1])) == 0)			p = root1(p->kids[0]);		break;	case NOT:		if (warn++ == 0)			warning("expression with no effect elided\n");		return root1(p->kids[0]);	case RIGHT:		if (p->kids[1] == 0)			return root1(p->kids[0]);		if (p->kids[0] && p->kids[0]->op == CALL+B		&&  p->kids[1] && p->kids[1]->op == INDIR+B)			/* avoid premature release of the CALL+B temporary */			return p->kids[0];		if (p->kids[0] && p->kids[0]->op == RIGHT		&&  p->kids[1] == p->kids[0]->kids[0])			/* de-construct e++ construction */			return p->kids[0]->kids[1];		p = tree(RIGHT, p->type, root1(p->kids[0]), root1(p->kids[1]));		return p->kids[0] || p->kids[1] ? p : (Tree)0;	case EQ:  case NE:  case GT:   case GE:  case LE:  case LT: 	case ADD: case SUB: case MUL:  case DIV: case MOD:	case LSH: case RSH: case BAND: case BOR: case BXOR:		if (warn++ == 0)			warning("expression with no effect elided\n");		p = tree(RIGHT, p->type, root1(p->kids[0]), root1(p->kids[1]));		return p->kids[0] || p->kids[1] ? p : (Tree)0;	case INDIR:		if (p->type->size == 0 && unqual(p->type) != voidtype)			warning("reference to `%t' elided\n", p->type);		if (isptr(p->kids[0]->type) && isvolatile(p->kids[0]->type->type))			warning("reference to `volatile %t' elided\n", p->type);		/* fall thru */	case NEG: case BCOM: case FIELD:		if (warn++ == 0)			warning("expression with no effect elided\n");		return root1(p->kids[0]);	case ADDRL: case ADDRG: case ADDRF: case CNST:		if (needconst)			return p;		if (warn++ == 0)			warning("expression with no effect elided\n");		return NULL;	case CVF:		if (optype(p->op) == I		|| p->type->size < p->kids[0]->type->size)			if (warn++ == 0)				warning("expression with no effect elided\n");		return root1(p->kids[0]);	case CVI:		if ((optype(p->op) == U || optype(p->op) == I)		&& p->type->size < p->kids[0]->type->size		&& specific(p->kids[0]->op) != CALL+I)			if (warn++ == 0)				warning("expression with no effect elided\n");		return root1(p->kids[0]);	case CVU: case CVP:		if (optype(p->op) == U && p->type->size <  p->kids[0]->type->size		||  optype(p->op) == I && p->type->size <= p->kids[0]->type->size)			if (warn++ == 0)				warning("expression with no effect elided\n");		return root1(p->kids[0]);	case ARG: case ASGN: case CALL: case JUMP: case LABEL:		break;	default: assert(0);	}	return p;}Tree root(Tree p) {	warn = 0;	return root1(p);}char *opname(int op) {	static char *opnames[] = {	"",	"CNST",	"ARG",	"ASGN",	"INDIR",	"CVC",	"CVD",	"CVF",	"CVI",	"CVP",	"CVS",	"CVU",	"NEG",	"CALL",	"*LOAD*",	"RET",	"ADDRG",	"ADDRF",	"ADDRL",	"ADD",	"SUB",	"LSH",	"MOD",	"RSH",	"BAND",	"BCOM",	"BOR",	"BXOR",	"DIV",	"MUL",	"EQ",	"GE",	"GT",	"LE",	"LT",	"NE",	"JUMP",	"LABEL",	"AND",	"NOT",	"OR",	"COND",	"RIGHT",	"FIELD"	}, *suffixes[] = {		"0", "F", "D", "C", "S", "I", "U", "P", "V", "B",		"10","11","12","13","14","15"	};	if (generic(op) >= AND && generic(op) <= FIELD && opsize(op) == 0)		return opnames[opindex(op)];	return stringf("%s%s%s",		opindex(op) > 0 && opindex(op) < NELEMS(opnames) ?			opnames[opindex(op)] : stringd(opindex(op)),		suffixes[optype(op)], opsize(op) > 0 ? stringd(opsize(op)) : "");}int nodeid(Tree p) {	int i = 1;	ids[nid].node = p;	while (ids[i].node != p)		i++;	if (i == nid)		ids[nid++].printed = 0;	return i;}/* printed - return pointer to ids[id].printed */int *printed(int id) {	if (id)		return &ids[id].printed;	nid = 1;	return 0;}/* printtree - print tree p on fd */void printtree(Tree p, int fd) {	(void)printed(0);	printtree1(p, fd, 1);}/* printtree1 - recursively print tree p */static void printtree1(Tree p, int fd, int lev) {	FILE *f = fd == 1 ? stdout : stderr;	int i;	static char blanks[] = "                                                   ";	if (p == 0 || *printed(i = nodeid(p)))		return;	fprint(f, "#%d%S%S", i, blanks, i < 10 ? 2 : i < 100 ? 1 : 0, blanks, lev);	fprint(f, "%s %t", opname(p->op), p->type);	*printed(i) = 1;	for (i = 0; i < NELEMS(p->kids); i++)		if (p->kids[i])			fprint(f, " #%d", nodeid(p->kids[i]));	if (p->op == FIELD && p->u.field)		fprint(f, " %s %d..%d", p->u.field->name,			fieldsize(p->u.field) + fieldright(p->u.field), fieldright(p->u.field));	else if (generic(p->op) == CNST)		fprint(f, " %s", vtoa(p->type, p->u.v));	else if (p->u.sym)		fprint(f, " %s", p->u.sym->name);	if (p->node)		fprint(f, " node=%p", p->node);	fprint(f, "\n");	for (i = 0; i < NELEMS(p->kids); i++)		printtree1(p->kids[i], fd, lev + 1);}