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;
}
/* 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 *
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 *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 *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 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 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;
}
/* 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 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 Node *simpucon(Simp *s, Node *n, Node *dst)
{
Node *tmp, *u, *tag, *elt, *sz;
Node *r;
Type *ty;
Ucon *uc;
size_t i;
/* find the ucon we're constructing here */
ty = tybase(n->expr.type);
uc = NULL;
for (i = 0; i < ty->nmemb; i++) {
if (!strcmp(namestr(n->expr.args[0]), namestr(ty->udecls[i]->name))) {
uc = ty->udecls[i];
break;
}
}
if (!uc)
die("Couldn't find union constructor");
if (dst)
tmp = dst;
else
tmp = temp(s, n);
/* Set the tag on the ucon */
u = addr(s, tmp, mktype(n->line, Tyuint));
tag = mkintlit(n->line, uc->id);
tag->expr.type = mktype(n->line, Tyuint);
append(s, set(deref(u), tag));
/* fill the value, if needed */
if (!uc->etype)
return tmp;
elt = rval(s, n->expr.args[1], NULL);
u = addk(u, Wordsz);
if (stacktype(uc->etype)) {
elt = addr(s, elt, uc->etype);
sz = disp(n->line, tysize(uc->etype));
r = mkexpr(n->line, Oblit, u, elt, sz, NULL);
} else {
r = set(deref(u), elt);
}
append(s, r);
return tmp;
}
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;
}
}
}
/* We treat all integer types, boolean types, etc, as having 2^n constructors.
*
* since, of course, we can't represent all of the constructors for 64 bit
* integers using 64 bit values, we just approximate it. We'd have failed (run
* out of memory, etc) long before getting to this code if we actually had that
* many branches of the switch statements anyways.
*/
static size_t nconstructors(Type *t)
{
if (!t)
return 0;
t = tybase(t);
switch (t->type) {
case Tyvoid: return 0; break;
case Tybool: return 2; break;
case Tychar: return 0x10ffff; break;
/* signed ints */
case Tyint8: return 0x100; break;
case Tyint16: return 0x10000; break;
case Tyint32: return 0x100000000; break;
case Tyint: return 0x100000000; break;
case Tyint64: return ~0ull; break;
/* unsigned ints */
case Tybyte: return 0x100; break;
case Tyuint8: return 0x100; break;
case Tyuint16: return 0x10000; break;
case Tyuint32: return 0x100000000; break;
case Tyuint: return 0x100000000; break;
case Tyuint64: return ~0ull; break;
/* floats */
case Tyflt32: return ~0ull; break;
case Tyflt64: return ~0ull; break;
/* complex types */
case Typtr: return 1; break;
case Tyarray: return 1; break;
case Tytuple: return 1; break;
case Tystruct: return 1;
case Tyunion: return t->nmemb; break;
case Tyslice: return ~0ULL; break;
case Tyvar: case Typaram: case Tyunres: case Tyname:
case Tybad: case Tyvalist: case Tygeneric: case Ntypes:
case Tyfunc: case Tycode:
die("Invalid constructor type %s in match", tystr(t));
break;
}
return 0;
}
static Ucon *finducon(Node *n)
{
size_t i;
Type *t;
Ucon *uc;
t = tybase(n->expr.type);
if (exprop(n) != Oucon)
return NULL;
for (i = 0; i < t->nmemb; i++) {
uc = t->udecls[i];
if (!strcmp(namestr(uc->name), namestr(n->expr.args[0])))
return uc;
}
die("No ucon?!?");
return NULL;
}
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 *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;
}
Node *fold(Node *n, int foldvar)
{
Node **args, *r;
Type *t;
vlong a, b;
size_t i;
if (!n)
return NULL;
if (n->type != Nexpr)
return n;
r = NULL;
args = n->expr.args;
for (i = 0; i < n->expr.nargs; i++)
args[i] = fold(args[i], foldvar);
switch (exprop(n)) {
case Ovar:
if (foldvar && issmallconst(decls[n->expr.did]))
r = fold(decls[n->expr.did]->decl.init, foldvar);
break;
case Oadd:
/* x + 0 = 0 */
if (isval(args[0], 0))
r = args[1];
if (isval(args[1], 0))
r = args[0];
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a + b, exprtype(n));
break;
case Osub:
/* x - 0 = 0 */
if (isval(args[1], 0))
r = args[0];
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a - b, exprtype(n));
break;
case Omul:
/* 1 * x = x */
if (isval(args[0], 1))
r = args[1];
if (isval(args[1], 1))
r = args[0];
/* 0 * x = 0 */
if (isval(args[0], 0))
r = args[0];
if (isval(args[1], 0))
r = args[1];
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a * b, exprtype(n));
break;
case Odiv:
/* x/1 = x */
if (isval(args[1], 1))
r = args[0];
/* 0/x = 0 */
if (isval(args[1], 0))
r = args[1];
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a / b, exprtype(n));
break;
case Omod:
/* x%1 = x */
if (isval(args[1], 0))
r = args[0];
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a % b, exprtype(n));
break;
case Oneg:
if (islit(args[0], &a))
r = val(n->line, -a, exprtype(n));
break;
case Obsl:
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a << b, exprtype(n));
break;
case Obsr:
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a >> b, exprtype(n));
break;
case Obor:
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a | b, exprtype(n));
break;
case Oband:
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a & b, exprtype(n));
break;
case Obxor:
if (islit(args[0], &a) && islit(args[1], &b))
r = val(n->line, a ^ b, exprtype(n));
break;
case Omemb:
t = tybase(exprtype(args[0]));
/* we only fold lengths right now */
if (t->type == Tyarray && !strcmp(namestr(args[1]), "len"))
r = t->asize;
break;
case Ocast:
r = foldcast(n);
break;
default:
break;
}
if (r)
return r;
else
return n;
}
int stacktype(Type *t)
{
/* the types are arranged in types.def such that this is true */
t = tybase(t);
return t->type >= Tyslice;
}
int floattype(Type *t)
{
t = tybase(t);
return t->type == Tyfloat32 || t->type == Tyfloat64;
}
static void umatch(Simp *s, Node *pat, Node *val, Type *t, Node *iftrue, Node *iffalse)
{
Node *v, *x, *y;
Node *deeper, *next;
Node **patarg;
Ucon *uc;
size_t i;
size_t off;
assert(pat->type == Nexpr);
t = tybase(t);
if (exprop(pat) == Ovar && !decls[pat->expr.did]->decl.isconst) {
v = assign(s, pat, val);
append(s, v);
jmp(s, iftrue);
return;
}
switch (t->type) {
/* Never supported */
case Tyvoid: case Tybad: case Tyvalist: case Tyvar:
case Typaram: case Tyunres: case Tyname: case Ntypes:
/* Should never show up */
case Tyslice:
die("Unsupported type for compare");
break;
case Tybool: case Tychar: case Tybyte:
case Tyint8: case Tyint16: case Tyint32: case Tyint:
case Tyuint8: case Tyuint16: case Tyuint32: case Tyuint:
case Tyint64: case Tyuint64: case Tylong: case Tyulong:
case Tyfloat32: case Tyfloat64:
case Typtr: case Tyfunc:
v = mkexpr(pat->line, Oeq, pat, val, NULL);
v->expr.type = mktype(pat->line, Tybool);
cjmp(s, v, iftrue, iffalse);
break;
/* We got lucky. The structure of tuple, array, and struct literals
* is the same, so long as we don't inspect the type, so we can
* share the code*/
case Tystruct: case Tytuple: case Tyarray:
patarg = pat->expr.args;
off = 0;
for (i = 0; i < pat->expr.nargs; i++) {
off = tyalign(off, size(patarg[i]));
next = genlbl();
v = load(addk(addr(s, val, exprtype(patarg[i])), off));
umatch(s, patarg[i], v, exprtype(patarg[i]), next, iffalse);
append(s, next);
off += size(patarg[i]);
}
jmp(s, iftrue);
break;
case Tyunion:
uc = finducon(pat);
if (!uc)
uc = finducon(val);
deeper = genlbl();
x = uconid(s, pat);
y = uconid(s, val);
v = mkexpr(pat->line, Oeq, x, y, NULL);
v->expr.type = tyintptr;
cjmp(s, v, deeper, iffalse);
append(s, deeper);
if (uc->etype) {
pat = patval(s, pat, uc->etype);
val = patval(s, val, uc->etype);
umatch(s, pat, val, uc->etype, iftrue, iffalse);
}
break;
}
}
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;
}
Node *fold(Node *n, int foldvar)
{
Node **args, *r;
Type *t;
vlong a, b;
size_t i;
if (!n)
return NULL;
if (n->type != Nexpr)
return n;
r = NULL;
args = n->expr.args;
if (n->expr.idx)
n->expr.idx = fold(n->expr.idx, foldvar);
for (i = 0; i < n->expr.nargs; i++)
args[i] = fold(args[i], foldvar);
switch (exprop(n)) {
case Ovar:
if (foldvar && issmallconst(decls[n->expr.did]))
r = fold(decls[n->expr.did]->decl.init, foldvar);
break;
case Oadd:
/* x + 0 = 0 */
if (isintval(args[0], 0))
r = args[1];
if (isintval(args[1], 0))
r = args[0];
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a + b, exprtype(n));
break;
case Osub:
/* x - 0 = 0 */
if (isintval(args[1], 0))
r = args[0];
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a - b, exprtype(n));
break;
case Omul:
/* 1 * x = x */
if (isintval(args[0], 1))
r = args[1];
if (isintval(args[1], 1))
r = args[0];
/* 0 * x = 0 */
if (isintval(args[0], 0))
r = args[0];
if (isintval(args[1], 0))
r = args[1];
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a * b, exprtype(n));
break;
case Odiv:
/* x/0 = error */
if (isintval(args[1], 0))
fatal(args[1], "division by zero");
/* x/1 = x */
if (isintval(args[1], 1))
r = args[0];
/* 0/x = 0 */
if (isintval(args[1], 0))
r = args[1];
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a / b, exprtype(n));
break;
case Omod:
/* x%0 = error */
if (isintval(args[1], 0))
fatal(args[1], "division by zero");
/* x%1 = 0 */
if (isintval(args[1], 1))
r = val(n->loc, 0, exprtype(n));
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a % b, exprtype(n));
break;
case Oneg:
if (getintlit(args[0], &a))
r = val(n->loc, -a, exprtype(n));
break;
case Obsl:
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a << b, exprtype(n));
break;
case Obsr:
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a >> b, exprtype(n));
break;
case Obor:
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a | b, exprtype(n));
break;
case Oband:
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a & b, exprtype(n));
break;
case Obxor:
if (getintlit(args[0], &a) && getintlit(args[1], &b))
r = val(n->loc, a ^ b, exprtype(n));
break;
case Omemb:
t = tybase(exprtype(args[0]));
/* we only fold lengths right now */
if (t->type == Tyarray && !strcmp(namestr(args[1]), "len")) {
r = t->asize;
r->expr.type = exprtype(n);
}
break;
case Oarr:
if (n->expr.nargs > 0)
qsort(n->expr.args, n->expr.nargs, sizeof(Node*), idxcmp);
break;
case Ocast:
r = foldcast(n);
break;
default:
break;
}
if (r && n->expr.idx)
r->expr.idx = n->expr.idx;
if (r)
return r;
else
return n;
}
