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#include "c.h"
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 CVI: case CVF: case CVU: case CVP:
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 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);
}
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