static Node *assign(Simp *s, Node *lhs, Node *rhs)
{
Node *t, *u, *v, *r;
if (exprop(lhs) == Otup) {
r = destructure(s, lhs, rhs);
} else {
t = lval(s, lhs);
u = rval(s, rhs, t);
/* if we stored the result into t, rval() should return that,
* so we know our work is done. */
if (u == t) {
r = t;
} else if (stacknode(lhs)) {
t = addr(s, t, exprtype(lhs));
u = addr(s, u, exprtype(lhs));
v = disp(lhs->line, size(lhs));
r = mkexpr(lhs->line, Oblit, t, u, v, NULL);
} else {
r = set(t, u);
}
}
return r;
}
static Node *slicebase(Simp *s, Node *n, Node *off)
{
Node *t, *u, *v;
Type *ty;
int sz;
t = rval(s, n, NULL);
u = NULL;
ty = tybase(exprtype(n));
switch (ty->type) {
case Typtr: u = t; break;
case Tyarray: u = addr(s, t, base(exprtype(n))); break;
case Tyslice: u = load(addr(s, t, mktyptr(n->line, base(exprtype(n))))); break;
default: die("Unslicable type %s", tystr(n->expr.type));
}
/* safe: all types we allow here have a sub[0] that we want to grab */
if (off) {
off = ptrsized(s, rval(s, off, NULL));
sz = tysize(n->expr.type->sub[0]);
v = mul(off, disp(n->line, sz));
return add(u, v);
} else {
return u;
}
}
static Node *foldcast(Node *n)
{
Type *to, *from;
Node *sub;
sub = n->expr.args[0];
to = exprtype(n);
from = exprtype(sub);
switch (tybase(to)->type) {
case Tybool:
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tychar: case Tybyte:
case Typtr:
switch (tybase(from)->type) {
case Tybool:
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tychar: case Tybyte:
case Typtr:
if (exprop(sub) == Olit || tybase(from)->type == tybase(to)->type) {
sub->expr.type = to;
return sub;
} else {
return n;
}
default:
return n;
}
default:
return n;
}
return n;
}
/* Takes a tuple and binds the i'th element of it to the
* i'th name on the rhs of the assignment. */
static Node *destructure(Simp *s, Node *lhs, Node *rhs)
{
Node *plv, *prv, *lv, *sz, *stor, **args;
size_t off, i;
args = lhs->expr.args;
rhs = rval(s, rhs, NULL);
off = 0;
for (i = 0; i < lhs->expr.nargs; i++) {
lv = lval(s, args[i]);
off = tyalign(off, size(lv));
prv = add(addr(s, rhs, exprtype(args[i])), disp(rhs->line, off));
if (stacknode(args[i])) {
sz = disp(lhs->line, size(lv));
plv = addr(s, lv, exprtype(lv));
stor = mkexpr(lhs->line, Oblit, plv, prv, sz, NULL);
} else {
stor = set(lv, load(prv));
}
append(s, stor);
off += size(lv);
}
return NULL;
}
static Node *
comparecomplex(Flattenctx *s, Node *n, Op op)
{
Type *ty;
Node *l, *r, *e;
/* special case: unions with nullary constructors can be compared easily. */
ty = tybase(exprtype(n->expr.args[0]));
if (ty->type == Tyunion && isenum(ty)) {
l = mkexpr(n->loc, Outag, rval(s, n->expr.args[0]), NULL);
r = mkexpr(n->loc, Outag, rval(s, n->expr.args[1]), NULL);
l->expr.type = mktype(n->loc, Tyuint32);
r->expr.type = mktype(n->loc, Tyuint32);
if (op == Oeq)
e = mkexpr(n->loc, Oueq, l, r, NULL);
else if (op == One)
e = mkexpr(n->loc, Oune, l, r, NULL);
else
fatal(n, "unsupported operator %s for enum union", opstr[op]);
e->expr.type = mktype(n->loc, Tybool);
return e;
}
fatal(n, "cannot compare values of type %s for equality\n",
tystr(exprtype(n->expr.args[0])));
return NULL;
}
static Node *
asn(Node *a, Node *b)
{
Node *n;
assert(a != NULL && b != NULL);
if (tybase(exprtype(a))->type == Tyvoid)
return a;
n = mkexpr(a->loc, Oasn, a, b, NULL);
n->expr.type = exprtype(a);
return n;
}
static Node *seqlen(Simp *s, Node *n, Type *ty)
{
Node *t, *r;
if (exprtype(n)->type == Tyslice) {
t = slicelen(s, n);
r = simpcast(s, t, ty);
} else if (exprtype(n)->type == Tyarray) {
t = exprtype(n)->asize;
r = simpcast(s, t, ty);
} else {
r = NULL;
}
return r;
}
Node *gensimpmatch(Node *m)
{
Dtree *t, *leaf;
Node **pat, **cap;
size_t npat, ncap;
size_t i;
Node *n;
pat = m->matchstmt.matches;
npat = m->matchstmt.nmatches;
t = mkdtree();
for (i = 0; i < npat; i++) {
cap = NULL;
ncap = 0;
leaf = addpat(t, pat[i]->match.pat, m->matchstmt.val, &cap, &ncap);
/* TODO: NULL is returned by unsupported patterns. */
if (!leaf)
return NULL;
if (leaf->act)
fatal(pat[i], "pattern matched by earlier case on line %d", leaf->act->loc.line);
leaf->act = pat[i]->match.block;
leaf->cap = cap;
leaf->ncap = ncap;
}
if (!exhaustivematch(m, t, exprtype(m->matchstmt.val)))
fatal(m, "nonexhaustive pattern set in match statement");
n = genmatch(m->loc, t);
dump(n, stdout);
return n;
}
/* Simplifies taking a slice of an array, pointer,
* or other slice down to primitive pointer operations */
static Node *simpslice(Simp *s, Node *n, Node *dst)
{
Node *t;
Node *start, *end;
Node *base, *sz, *len;
Node *stbase, *stlen;
if (dst)
t = dst;
else
t = temp(s, n);
/* *(&slice) = (void*)base + off*sz */
base = slicebase(s, n->expr.args[0], n->expr.args[1]);
start = ptrsized(s, rval(s, n->expr.args[1], NULL));
end = ptrsized(s, rval(s, n->expr.args[2], NULL));
len = sub(end, start);
/* we can be storing through a pointer, in the case
* of '*foo = bar'. */
if (tybase(exprtype(t))->type == Typtr) {
stbase = set(simpcast(s, t, mktyptr(t->line, tyintptr)), base);
sz = addk(simpcast(s, t, mktyptr(t->line, tyintptr)), Ptrsz);
} else {
stbase = set(deref(addr(s, t, tyintptr)), base);
sz = addk(addr(s, t, tyintptr), Ptrsz);
}
/* *(&slice + ptrsz) = len */
stlen = set(deref(sz), len);
append(s, stbase);
append(s, stlen);
return t;
}
static Node *addk(Node *n, uvlong v)
{
Node *k;
k = mkintlit(n->line, v);
k->expr.type = exprtype(n);
return add(n, k);
}
static Dtree *addunion(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap)
{
Node *elt, *tag, *id;
int32_t t1, t2;
Dtree *sub;
Ucon *uc;
size_t i;
if (t->any)
return t->any;
uc = finducon(tybase(exprtype(pat)), pat->expr.args[0]);
t2 = uc->id;
/* if we have the value already... */
sub = NULL;
for (i = 0; i < t->nval; i++) {
tag = t->val[i]->expr.args[0];
t1 = tag->lit.intval;
if (t1 == t2) {
if (pat->expr.nargs > 1) {
elt = uvalue(val, exprtype(pat->expr.args[1]));
return addpat(t->sub[i], pat->expr.args[1], elt, cap, ncap);
} else {
return t->sub[i];
}
}
}
/* otherwise create a new match */
sub = mkdtree();
sub->patexpr = pat;
tag = mkexpr(pat->loc, Outag, val, NULL);
tag->expr.type = mktype(pat->loc, Tyint32);
id = mkintlit(pat->loc, uc->id);
id->expr.type = mktype(pat->loc, Tyint32);
lappend(&t->val, &t->nval, id);
lappend(&t->sub, &t->nsub, sub);
lappend(&t->load, &t->nload, tag);
if (pat->expr.nargs == 2) {
elt = uvalue(val, exprtype(pat->expr.args[1]));
sub = addpat(sub, pat->expr.args[1], elt, cap, ncap);
}
return sub;
}
static Node *
seqlen(Flattenctx *s, Node *n, Type *ty)
{
Node *r;
if (!ty)
ty = n->expr.type;
if (exprtype(n)->type == Tyarray) {
r = mkexpr(n->loc, Osllen, rval(s, n), NULL);
r->expr.type = ty;
} else if (exprtype(n)->type == Tyslice) {
r = mkexpr(n->loc, Osllen, rval(s, n), NULL);
r->expr.type = ty;
} else {
die("invalid seq type for len");
}
return r;
}
static Node *
subk(Node *n, uvlong v)
{
Node *k;
k = mkintlit(n->loc, v);
k->expr.type = exprtype(n);
return sub(n, k);
}
static Node *membaddr(Simp *s, Node *n)
{
Node *t, *u, *r;
Node **args;
Type *ty;
args = n->expr.args;
ty = tybase(exprtype(args[0]));
if (ty->type == Typtr) {
t = lval(s, args[0]);
} else {
t = addr(s, lval(s, args[0]), exprtype(n));
}
u = disp(n->line, offset(args[0], args[1]));
r = add(t, u);
r->expr.type = mktyptr(n->line, n->expr.type);
return r;
}
static Node *set(Node *a, Node *b)
{
Node *n;
assert(a != NULL && b != NULL);
assert(exprop(a) == Ovar || exprop(a) == Oderef);
n = mkexpr(a->line, Oset, a, b, NULL);
n->expr.type = exprtype(a);
return n;
}
static Node *arrayelt(Node *n, size_t i)
{
Node *idx, *elt;
idx = mkintlit(n->loc, i);
idx->expr.type = mktype(n->loc, Tyuint64);
elt = mkexpr(n->loc, Oidx, n, idx, NULL);
elt->expr.type = tybase(exprtype(n))->sub[0];
return elt;
}
static int issmallconst(Node *dcl)
{
Type *t;
if (!dcl->decl.isconst)
return 0;
if (!dcl->decl.init)
return 0;
t = tybase(exprtype(dcl->decl.init));
if (t->type <= Tyfloat64)
return 1;
return 0;
}
static Node *idxaddr(Simp *s, Node *seq, Node *idx)
{
Node *a, *t, *u, *v; /* temps */
Node *r; /* result */
Type *ty;
size_t sz;
a = rval(s, seq, NULL);
ty = exprtype(seq)->sub[0];
if (exprtype(seq)->type == Tyarray)
t = addr(s, a, ty);
else if (seq->expr.type->type == Tyslice)
t = load(addr(s, a, mktyptr(seq->line, ty)));
else
die("Can't index type %s\n", tystr(seq->expr.type));
assert(t->expr.type->type == Typtr);
u = rval(s, idx, NULL);
u = ptrsized(s, u);
sz = tysize(ty);
v = mul(u, disp(seq->line, sz));
r = add(t, v);
return r;
}
static int isexhaustive(Dtree *dt)
{
Type *subt;
size_t i;
if (dt->any)
return 1;
if (dt->nsub > 0) {
subt = tybase(exprtype(dt->sub[0]->patexpr));
if (dt->nsub != nconstructors(subt))
return 0;
}
switch (exprop(dt->patexpr)) {
case Ovar:
return 1;
case Olit:
return 1;
case Oucon:
for (i = 0; i < dt->nsub; i++)
if (!isexhaustive(dt->sub[i]))
return 0;
return 1;
break;
case Otup:
for (i = 0; i < dt->nsub; i++)
if (!isexhaustive(dt->sub[i]))
return 0;
return 1;
break;
case Oarr:
for (i = 0; i < dt->nsub; i++)
if (!isexhaustive(dt->sub[i]))
return 0;
return 1;
break;
case Ostruct:
for (i = 0; i < dt->nsub; i++)
if (!isexhaustive(dt->sub[i]))
return 0;
return 1;
break;
default:
die("Invalid pattern in exhaustivenes check. BUG.");
break;
}
return 0;
}
static void checkundef(Node *n, Reaching *r, Bitset *reach, Bitset *kill)
{
size_t i, j, did;
Node *def;
Type *t;
if (n->type != Nexpr)
return;
if (exprop(n) == Ovar) {
did = n->expr.did;
for (j = 0; j < r->ndefs[did]; j++) {
t = tybase(exprtype(n));
if (t->type == Tystruct || t->type == Tyunion || t->type == Tyarray || t->type == Tytuple)
continue;
if (bshas(kill, r->defs[did][j]))
continue;
if (!bshas(reach, r->defs[did][j]))
continue;
def = nodes[r->defs[did][j]];
if (exprop(def) == Oundef)
fatal(n, "%s used before definition", namestr(n->expr.args[0]));
}
} else {
switch (exprop(n)) {
case Oset:
case Oasn:
case Oblit:
checkundef(n->expr.args[1], r, reach, kill);
break;
case Oaddr:
case Oslice:
/* these don't actually look at the of args[0], so they're ok. */
for (i = 1; i < n->expr.nargs; i++)
checkundef(n->expr.args[i], r, reach, kill);
break;
case Ocall:
for (i = 1; i < n->expr.nargs; i++)
if (exprop(n->expr.args[i]) != Oaddr)
checkundef(n->expr.args[i], r, reach, kill);
break;
default:
for (i = 0; i < n->expr.nargs; i++)
checkundef(n->expr.args[i], r, reach, kill);
break;
}
}
}
static Node *assignat(Simp *s, Node *r, size_t off, Node *val)
{
Node *pval, *pdst;
Node *sz;
Node *st;
val = rval(s, val, NULL);
pdst = add(r, disp(val->line, off));
if (stacknode(val)) {
sz = disp(val->line, size(val));
pval = addr(s, val, exprtype(val));
st = mkexpr(val->line, Oblit, pdst, pval, sz, NULL);
} else {
st = set(deref(pdst), val);
}
append(s, st);
return r;
}
/* Simplify tuple construction to a stack allocated
* value by evaluating the rvalue of each node on the
* rhs and assigning it to the correct offset from the
* head of the tuple. */
static Node *simptup(Simp *s, Node *n, Node *dst)
{
Node **args;
Node *r;
size_t i, off;
args = n->expr.args;
if (!dst)
dst = temp(s, n);
r = addr(s, dst, exprtype(dst));
off = 0;
for (i = 0; i < n->expr.nargs; i++) {
off = tyalign(off, size(args[i]));
assignat(s, r, off, args[i]);
off += size(args[i]);
}
return dst;
}
static void
dispose(Flattenctx *s, Stab *st, size_t n)
{
Node *e, *call, *func;
Trait *tr;
Type *ty;
size_t i;
tr = traittab[Tcdisp];
/* dispose in reverse order of appearance */
for (i = st->nautotmp; i-- > n;) {
e = st->autotmp[i];
ty = exprtype(e);
func = traitfn(Zloc, tr, "__dispose__", ty);
call = mkexpr(Zloc, Ocall, func, e, NULL);
call->expr.type = mktype(Zloc, Tyvoid);
flatten(s, call);
}
}
static Node *visit(Simp *s, Node *n)
{
size_t i;
Node *r;
for (i = 0; i < n->expr.nargs; i++)
n->expr.args[i] = rval(s, n->expr.args[i], NULL);
if (ispure(n)) {
r = n;
} else {
if (exprtype(n)->type == Tyvoid) {
r = NULL;
append(s, n);
} else {
r = temp(s, n);
append(s, set(r, n));
}
}
return r;
}
static Dtree *addstruct(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap)
{
Node *elt, *memb;
Type *ty;
size_t i, j;
if (t->any)
return t->any;
for (i = 0; i < pat->expr.nargs; i++) {
elt = pat->expr.args[i];
for (j = 0; j < t->nval; j++) {
if (!strcmp(namestr(elt->expr.idx), namestr(t->val[j]->expr.idx))) {
ty = exprtype(pat->expr.args[i]);
memb = structmemb(val, elt->expr.idx, ty);
t = addpat(t, pat->expr.args[i], memb, cap, ncap);
break;
}
}
}
return t;
}
void dtdumpnode(Dtree *dt, FILE *f, int depth, int iswild)
{
Node *e;
size_t i;
char *s;
if (dt->patexpr) {
e = dt->patexpr;
s = tystr(exprtype(e));
indentf(depth, "%s%s %s : %s\n", iswild ? "WILDCARD " : "", opstr[exprop(e)], dtnodestr(e), s);
free(s);
}
if (dt->cap)
for (i = 0; i < dt->ncap; i++)
indentf(depth + 1, "capture %s\n", dtnodestr(dt->cap[i]));
if (dt->act)
indentf(depth + 1, "action\n");
for (i = 0; i < dt->nsub; i++)
dtdumpnode(dt->sub[i], f, depth + 1, 0);
if (dt->any)
dtdumpnode(dt->any, f, depth + 1, 1);
}
static Node *
visit(Flattenctx *s, Node *n)
{
size_t i;
Node *r;
for (i = 0; i < n->expr.nargs; i++)
n->expr.args[i] = rval(s, n->expr.args[i]);
if (opispure[exprop(n)]) {
r = n;
} else {
if (exprtype(n)->type == Tyvoid) {
r = mkexpr(n->loc, Olit, mkvoid(n->loc), NULL);
r->expr.type = mktype(n->loc, Tyvoid);
append(s, n);
} else {
r = temp(s, n);
append(s, asn(r, n));
}
}
return r;
}
/* gets the byte offset of 'memb' within the aggregate type 'aggr' */
static size_t offset(Node *aggr, Node *memb)
{
Type *ty;
Node **nl;
size_t i;
size_t off;
ty = tybase(exprtype(aggr));
if (ty->type == Typtr)
ty = tybase(ty->sub[0]);
assert(ty->type == Tystruct);
nl = ty->sdecls;
off = 0;
for (i = 0; i < ty->nmemb; i++) {
off = tyalign(off, size(nl[i]));
if (!strcmp(namestr(memb), declname(nl[i])))
return off;
off += size(nl[i]);
}
die("Could not find member %s in struct", namestr(memb));
return -1;
}
static Dtree *addpat(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap)
{
Dtree *ret;
Node *dcl;
if (pat == NULL)
return t;
pat = fold(pat, 1);
switch (exprop(pat)) {
case Ovar:
dcl = decls[pat->expr.did];
if (dcl->decl.isconst)
ret = addpat(t, dcl->decl.init, val, cap, ncap);
else
ret = addwild(t, pat, val, cap, ncap);
break;
case Oucon:
ret = addunion(t, pat, val, cap, ncap);
break;
case Olit:
ret = addlit(t, pat, val, cap, ncap);
break;
case Otup:
ret = addtup(t, pat, val, cap, ncap);
break;
case Oarr:
ret = addarr(t, pat, val, cap, ncap);
break;
case Ostruct:
ret = addstruct(t, pat, val, cap, ncap);
break;
case Ogap:
ret = addwild(t, pat, val, NULL, NULL);
break;
default:
ret = NULL;
fatal(pat, "unsupported pattern %s of type %s", opstr[exprop(pat)], tystr(exprtype(pat)));
break;
}
return ret;
}
static Node *simpcast(Simp *s, Node *val, Type *to)
{
Node *r;
Type *t;
r = NULL;
/* do the type conversion */
switch (tybase(to)->type) {
case Tybool:
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tylong: case Tyulong:
case Tychar: case Tybyte:
case Typtr:
t = tybase(exprtype(val));
switch (t->type) {
/* ptr -> slice conversion is disallowed */
case Tyslice:
if (t->type == Typtr)
fatal(val->line, "Bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
r = slicebase(s, val, NULL);
break;
/* signed conversions */
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyint: case Tylong:
r = intconvert(s, val, to, 1);
break;
/* unsigned conversions */
case Tybool:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyuint: case Tyulong: case Tychar: case Tybyte:
case Typtr:
r = intconvert(s, val, to, 0);
break;
case Tyfloat32: case Tyfloat64:
if (tybase(to)->type == Typtr)
fatal(val->line, "Bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
r = mkexpr(val->line, Oflt2int, rval(s, val, NULL), NULL);
r->expr.type = to;
break;
default:
fatal(val->line, "Bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
}
break;
case Tyfloat32: case Tyfloat64:
t = tybase(exprtype(val));
switch (t->type) {
case Tyint8: case Tyint16: case Tyint32: case Tyint64:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint64:
case Tyint: case Tyuint: case Tylong: case Tyulong:
case Tychar: case Tybyte:
r = mkexpr(val->line, Oflt2int, rval(s, val, NULL), NULL);
r->expr.type = to;
break;
default:
fatal(val->line, "Bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
break;
}
break;
/* no other destination types are handled as things stand */
default:
fatal(val->line, "Bad cast from %s to %s",
tystr(exprtype(val)), tystr(to));
}
return r;
}
