Tree asgntree(int op, Tree l, Tree r) {
Type aty, ty;
r = pointer(r);
ty = assign(l->type, r);
if (ty)
r = cast(r, ty);
else {
typeerror(ASGN, l, r);
if (r->type == voidtype)
r = retype(r, inttype);
ty = r->type;
}
if (l->op != FIELD)
l = lvalue(l);
aty = l->type;
if (isptr(aty))
aty = unqual(aty)->type;
if (isconst(aty)
|| (isstruct(aty) && unqual(aty)->u.sym->u.s.cfields)) {
if (isaddrop(l->op)
&& !l->u.sym->computed && !l->u.sym->generated)
error("assignment to const identifier `%s'\n",
l->u.sym->name);
else
error("assignment to const location\n");
}
if (l->op == FIELD) {
long n = 8 * l->u.field->type->size - fieldsize(l->u.field);
if (n > 0 && isunsigned(l->u.field->type))
r = bittree(BAND, r,
cnsttree(r->type, (unsigned long)fieldmask(l->u.field)));
else if (n > 0) {
if (r->op == CNST + I) {
n = r->u.v.i;
if (n & (1 << (fieldsize(l->u.field) - 1)))
n |= ~0UL << fieldsize(l->u.field);
r = cnsttree(r->type, n);
} else
r = shtree(RSH,
shtree(LSH, r, cnsttree(inttype, n)),
cnsttree(inttype, n));
}
}
if (isstruct(ty) && isaddrop(l->op) && iscallb(r))
return tree(RIGHT, ty,
tree(CALL + B, ty, r->kids[0]->kids[0], l),
idtree(l->u.sym));
return tree(mkop(op, ty), ty, l, r);
}
static Tree addtree(int op, Tree l, Tree r) {
Type ty = inttype;
if (isarith(l->type) && isarith(r->type)) {
ty = binary(l->type, r->type);
l = cast(l, ty);
r = cast(r, ty);
} else if (isptr(l->type) && isint(r->type))
return addtree(ADD, r, l);
else if ( isptr(r->type) && isint(l->type)
&& !isfunc(r->type->type))
{
long n;
ty = unqual(r->type);
n = unqual(ty->type)->size;
if (n == 0)
error("unknown size for type `%t'\n", ty->type);
l = cast(l, promote(l->type));
if (n > 1)
l = multree(MUL, cnsttree(signedptr, n), l);
if (isunsigned(l->type))
l = cast(l, unsignedptr);
else
l = cast(l, signedptr);
if (YYcheck && !isaddrop(r->op)) /* omit */
return nullcall(ty, YYcheck, r, l); /* omit */
return simplify(ADD, ty, l, r);
}
else
typeerror(op, l, r);
return simplify(op, ty, l, r);
}
int iscallb(Tree e) {
return e->op == RIGHT && e->kids[0] && e->kids[1]
&& e->kids[0]->op == CALL+B
&& e->kids[1]->op == INDIR+B
&& isaddrop(e->kids[1]->kids[0]->op)
&& e->kids[1]->kids[0]->u.sym->temporary;
}
static void swstmt(int loop, int lab, int lev) {
Tree e;
struct swtch sw;
Code head, tail;
t = gettok();
expect('(');
definept(NULL);
e = expr(')');
if (!isint(e->type)) {
error("illegal type `%t' in switch expression\n",
e->type);
e = retype(e, inttype);
}
e = cast(e, promote(e->type));
if (generic(e->op) == INDIR && isaddrop(e->kids[0]->op)
&& e->kids[0]->u.sym->type == e->type
&& !isvolatile(e->kids[0]->u.sym->type)) {
sw.sym = e->kids[0]->u.sym;
walk(NULL, 0, 0);
} else {
sw.sym = genident(REGISTER, e->type, level);
addlocal(sw.sym);
walk(asgn(sw.sym, e), 0, 0);
}
head = code(Switch);
sw.lab = lab;
sw.deflab = NULL;
sw.ncases = 0;
sw.size = SWSIZE;
sw.values = newarray(SWSIZE, sizeof *sw.values, FUNC);
sw.labels = newarray(SWSIZE, sizeof *sw.labels, FUNC);
refinc /= 10.0;
statement(loop, &sw, lev);
if (sw.deflab == NULL) {
sw.deflab = findlabel(lab);
definelab(lab);
if (sw.ncases == 0)
warning("switch statement with no cases\n");
}
if (findlabel(lab + 1)->ref)
definelab(lab + 1);
tail = codelist;
codelist = head->prev;
codelist->next = head->prev = NULL;
if (sw.ncases > 0)
swgen(&sw);
branch(lab);
head->next->prev = codelist;
codelist->next = head->next;
codelist = tail;
}
Tree unary(void) {
Tree p;
switch (t) {
case '*': t = gettok(); p = unary(); p = pointer(p);
if (isptr(p->type)
&& (isfunc(p->type->type) || isarray(p->type->type)))
p = retype(p, p->type->type);
else {
if (YYnull)
p = nullcheck(p);
p = rvalue(p);
} break;
case '&': t = gettok(); p = unary(); if (isarray(p->type) || isfunc(p->type))
p = retype(p, ptr(p->type));
else
p = lvalue(p);
if (isaddrop(p->op) && p->u.sym->sclass == REGISTER)
error("invalid operand of unary &; `%s' is declared register\n", p->u.sym->name);
else if (isaddrop(p->op))
p->u.sym->addressed = 1;
break;
case '+': t = gettok(); p = unary(); p = pointer(p);
if (isarith(p->type))
p = cast(p, promote(p->type));
else
typeerror(ADD, p, NULL); break;
case '-': t = gettok(); p = unary(); p = pointer(p);
if (isarith(p->type)) {
Type ty = promote(p->type);
p = cast(p, ty);
if (isunsigned(ty)) {
warning("unsigned operand of unary -\n");
p = simplify(ADD, ty, simplify(BCOM, ty, p, NULL), cnsttree(ty, 1UL));
} else
p = simplify(NEG, ty, p, NULL);
} else
typeerror(SUB, p, NULL); break;
case '~': t = gettok(); p = unary(); p = pointer(p);
if (isint(p->type)) {
Type ty = promote(p->type);
p = simplify(BCOM, ty, cast(p, ty), NULL);
} else
typeerror(BCOM, p, NULL); break;
case '!': t = gettok(); p = unary(); p = pointer(p);
if (isscalar(p->type))
p = simplify(NOT, inttype, cond(p), NULL);
else
typeerror(NOT, p, NULL); break;
case INCR: t = gettok(); p = unary(); p = incr(INCR, pointer(p), consttree(1, inttype)); break;
case DECR: t = gettok(); p = unary(); p = incr(DECR, pointer(p), consttree(1, inttype)); break;
case TYPECODE: case SIZEOF: { int op = t;
Type ty;
p = NULL;
t = gettok();
if (t == '(') {
t = gettok();
if (istypename(t, tsym)) {
ty = typename();
expect(')');
} else {
p = postfix(expr(')'));
ty = p->type;
}
} else {
