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gc: fix reflect table method receiver

Fixes #451.
Fixes #770.

R=ken2
CC=golang-dev
https://golang.org/cl/2207045
This commit is contained in:
Russ Cox 2010-09-28 13:43:50 -04:00
parent 05cc83bf4e
commit 00ffd59c1a
8 changed files with 221 additions and 50 deletions

View File

@ -5168,6 +5168,6 @@ The following minimal alignment properties are guaranteed:
<h2 id="Implementation_differences"><span class="alert">Implementation differences - TODO</span></h2>
<ul>
<li><span class="alert">Implementation does not honor the restriction on goto statements and targets (no intervening declarations).</span></li>
<li><span class="alert">Method expressions are partially implemented.</span></li>
<li><span class="alert">Gccgo: Method expressions are partially implemented.</span></li>
<li><span class="alert">Gccgo: allows only one init() function per source file.</span></li>
</ul>

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@ -1010,7 +1010,7 @@ void walkrange(Node *n);
* reflect.c
*/
void dumptypestructs(void);
Type* methodfunc(Type *f, int use_receiver);
Type* methodfunc(Type *f, Type*);
Node* typename(Type *t);
Sym* typesym(Type *t);

View File

@ -100,16 +100,16 @@ lsort(Sig *l, int(*f)(Sig*, Sig*))
* return function type, receiver as first argument (or not).
*/
Type*
methodfunc(Type *f, int use_receiver)
methodfunc(Type *f, Type *receiver)
{
NodeList *in, *out;
Node *d;
Type *t;
in = nil;
if(use_receiver) {
if(receiver) {
d = nod(ODCLFIELD, N, N);
d->type = getthisx(f)->type->type;
d->type = receiver;
in = list(in, d);
}
for(t=getinargx(f)->type; t; t=t->down) {
@ -185,8 +185,8 @@ methods(Type *t)
a->name = method->name;
a->isym = methodsym(method, it, 1);
a->tsym = methodsym(method, t, 0);
a->type = methodfunc(f->type, 1);
a->mtype = methodfunc(f->type, 0);
a->type = methodfunc(f->type, t);
a->mtype = methodfunc(f->type, nil);
if(!(a->isym->flags & SymSiggen)) {
a->isym->flags |= SymSiggen;
@ -241,22 +241,27 @@ imethods(Type *t)
Sig *a, *all, *last;
int o;
Type *f;
Sym *method, *isym;
Prog *oldlist;
all = nil;
last = nil;
o = 0;
oldlist = nil;
for(f=t->type; f; f=f->down) {
if(f->etype != TFIELD)
fatal("imethods: not field");
if(f->type->etype != TFUNC || f->sym == nil)
continue;
method = f->sym;
a = mal(sizeof(*a));
a->name = f->sym->name;
if(!exportname(f->sym->name))
a->pkg = f->sym->pkg;
a->name = method->name;
if(!exportname(method->name))
a->pkg = method->pkg;
a->mtype = f->type;
a->offset = 0;
a->type = methodfunc(f->type, 0);
a->type = methodfunc(f->type, nil);
if(last && sigcmp(last, a) >= 0)
fatal("sigcmp vs sortinter %s %s", last->name, a->name);
if(last == nil)
@ -264,7 +269,43 @@ imethods(Type *t)
else
last->link = a;
last = a;
// Compiler can only refer to wrappers for
// named interface types.
if(t->sym == S)
continue;
// NOTE(rsc): Perhaps an oversight that
// IfaceType.Method is not in the reflect data.
// Generate the method body, so that compiled
// code can refer to it.
isym = methodsym(method, t, 0);
if(!(isym->flags & SymSiggen)) {
isym->flags |= SymSiggen;
if(oldlist == nil)
oldlist = pc;
genwrapper(t, f, isym, 0);
}
// Generate wrapper for pointer to interface type.
isym = methodsym(method, ptrto(t), 0);
if(!(isym->flags & SymSiggen)) {
isym->flags |= SymSiggen;
if(oldlist == nil)
oldlist = pc;
genwrapper(ptrto(t), f, isym, 0);
}
}
if(oldlist) {
// old list ended with AEND; change to ANOP
// so that the trampolines that follow can be found.
nopout(oldlist);
// start new data list
newplist();
}
return all;
}

View File

@ -17,6 +17,7 @@ static void implicitstar(Node**);
static int onearg(Node*, char*, ...);
static int twoarg(Node*);
static int lookdot(Node*, Type*, int);
static int looktypedot(Node*, Type*, int);
static void typecheckaste(int, int, Type*, NodeList*, char*);
static Type* lookdot1(Sym *s, Type *t, Type *f, int);
static int nokeys(NodeList*);
@ -497,6 +498,28 @@ reswitch:
yyerror("rhs of . must be a name"); // impossible
goto error;
}
sym = n->right->sym;
if(l->op == OTYPE) {
if(!looktypedot(n, t, 0)) {
if(looktypedot(n, t, 1))
yyerror("%#N undefined (cannot refer to unexported method %S)", n, n->right->sym);
else
yyerror("%#N undefined (type %T has no method %S)", n, t, n->right->sym);
goto error;
}
if(n->type->etype != TFUNC || n->type->thistuple != 1) {
yyerror("type %T has no method %hS", n->left->type, sym);
n->type = T;
goto error;
}
n->op = ONAME;
n->sym = methodsym(sym, l->type, 0);
n->type = methodfunc(n->type, l->type);
n->xoffset = 0;
n->class = PFUNC;
ok = Erv;
goto ret;
}
if(isptr[t->etype]) {
t = t->type;
if(t == T)
@ -504,34 +527,13 @@ reswitch:
n->op = ODOTPTR;
checkwidth(t);
}
sym = n->right->sym;
if(!lookdot(n, t, 0)) {
if(lookdot(n, t, 1))
yyerror("%#N undefined (cannot refer to unexported field %S)", n, n->right->sym);
yyerror("%#N undefined (cannot refer to unexported field or method %S)", n, n->right->sym);
else
yyerror("%#N undefined (type %T has no field %S)", n, t, n->right->sym);
yyerror("%#N undefined (type %T has no field or method %S)", n, t, n->right->sym);
goto error;
}
if(l->op == OTYPE) {
if(n->type->etype != TFUNC || n->type->thistuple != 1) {
yyerror("type %T has no method %hS", n->left->type, sym);
n->type = T;
goto error;
}
if(t->etype == TINTER) {
yyerror("method expression on interface not implemented");
n->type = T;
goto error;
}
n->op = ONAME;
n->sym = methodsym(sym, l->type, 0);
n->type = methodfunc(n->type, 1);
n->xoffset = 0;
getinargx(n->type)->type->type = l->type; // fix up receiver
n->class = PFUNC;
ok = Erv;
goto ret;
}
switch(n->op) {
case ODOTINTER:
case ODOTMETH:
@ -1381,6 +1383,55 @@ lookdot1(Sym *s, Type *t, Type *f, int dostrcmp)
return r;
}
static int
looktypedot(Node *n, Type *t, int dostrcmp)
{
Type *f1, *f2, *tt;
Sym *s;
s = n->right->sym;
if(t->etype == TINTER) {
f1 = lookdot1(s, t, t->type, dostrcmp);
if(f1 == T)
return 0;
if(f1->width == BADWIDTH)
fatal("lookdot badwidth %T %p", f1, f1);
n->right = methodname(n->right, t);
n->xoffset = f1->width;
n->type = f1->type;
n->op = ODOTINTER;
return 1;
}
tt = t;
if(t->sym == S && isptr[t->etype])
tt = t->type;
f2 = methtype(tt);
if(f2 == T)
return 0;
expandmeth(f2->sym, f2);
f2 = lookdot1(s, f2, f2->xmethod, dostrcmp);
// disallow T.m if m requires *T receiver
if(isptr[getthisx(f2->type)->type->type->etype]
&& !isptr[t->etype]
&& f2->embedded != 2
&& !isifacemethod(f2->type)) {
yyerror("invalid method expression %#N (needs pointer receiver: (*%T).%s)", n, t, f2->sym->name);
return 0;
}
n->right = methodname(n->right, t);
n->xoffset = f2->width;
n->type = f2->type;
n->op = ODOTMETH;
return 1;
}
static int
lookdot(Node *n, Type *t, int dostrcmp)
{
@ -1394,9 +1445,15 @@ lookdot(Node *n, Type *t, int dostrcmp)
if(t->etype == TSTRUCT || t->etype == TINTER)
f1 = lookdot1(s, t, t->type, dostrcmp);
f2 = methtype(n->left->type);
if(f2 != T)
f2 = lookdot1(s, f2, f2->method, dostrcmp);
f2 = T;
if(n->left->type == t || n->left->type->sym == S) {
f2 = methtype(t);
if(f2 != T) {
// Use f2->method, not f2->xmethod: adddot has
// already inserted all the necessary embedded dots.
f2 = lookdot1(s, f2, f2->method, dostrcmp);
}
}
if(f1 != T) {
if(f2 != T)
@ -1420,7 +1477,7 @@ lookdot(Node *n, Type *t, int dostrcmp)
tt = n->left->type;
dowidth(tt);
rcvr = getthisx(f2->type)->type->type;
if(n->left->op != OTYPE && !eqtype(rcvr, tt)) {
if(!eqtype(rcvr, tt)) {
if(rcvr->etype == tptr && eqtype(rcvr->type, tt)) {
checklvalue(n->left, "call pointer method on");
addrescapes(n->left);

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@ -1046,6 +1046,11 @@ func TestMethod(t *testing.T) {
t.Errorf("Type Method returned %d; want 250", i)
}
i = Typeof(&p).Method(0).Func.Call([]Value{NewValue(&p), NewValue(10)})[0].(*IntValue).Get()
if i != 250 {
t.Errorf("Pointer Type Method returned %d; want 250", i)
}
// Curried method of value.
i = NewValue(p).Method(0).Call([]Value{NewValue(10)})[0].(*IntValue).Get()
if i != 250 {
@ -1288,9 +1293,12 @@ func TestDotDotDot(t *testing.T) {
t.Error(s)
}
type inner struct{}
type inner struct {
x int
}
type outer struct {
y int
inner
}
@ -1307,3 +1315,42 @@ func TestNestedMethods(t *testing.T) {
}
}
}
type innerInt struct {
x int
}
type outerInt struct {
y int
innerInt
}
func (i *innerInt) m() int {
return i.x
}
func TestEmbeddedMethods(t *testing.T) {
typ := Typeof((*outerInt)(nil))
if typ.NumMethod() != 1 || typ.Method(0).Func.Get() != NewValue((*outerInt).m).(*FuncValue).Get() {
t.Errorf("Wrong method table for outerInt: (m=%p)", (*outerInt).m)
for i := 0; i < typ.NumMethod(); i++ {
m := typ.Method(i)
t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Get())
}
}
i := &innerInt{3}
if v := NewValue(i).Method(0).Call(nil)[0].(*IntValue).Get(); v != 3 {
t.Errorf("i.m() = %d, want 3", v)
}
o := &outerInt{1, innerInt{2}}
if v := NewValue(o).Method(0).Call(nil)[0].(*IntValue).Get(); v != 2 {
t.Errorf("i.m() = %d, want 2", v)
}
f := (*outerInt).m
if v := f(o); v != 2 {
t.Errorf("f(o) = %d, want 2", v)
}
}

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@ -597,10 +597,7 @@ func lookup(v reflect.Value, name string) reflect.Value {
for i := 0; i < n; i++ {
m := typ.Method(i)
mtyp := m.Type
// We must check receiver type because of a bug in the reflection type tables:
// it should not be possible to find a method with the wrong receiver type but
// this can happen due to value/pointer receiver mismatch.
if m.Name == name && mtyp.NumIn() == 1 && mtyp.NumOut() == 1 && mtyp.In(0) == typ {
if m.Name == name && mtyp.NumIn() == 1 && mtyp.NumOut() == 1 {
return v.Method(i).Call(nil)[0]
}
}

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@ -19,7 +19,7 @@ func (s S) val() int { return 1 }
func (s *S1) val() int { return 2 }
func (i I) val() int { return 3 }
func (i *I1) val() int { return 4 }
//func (t T) val() int { return 7 }
func (t T) val() int { return 7 }
func (t *T1) val() int { return 8 }
type Val interface {
@ -34,6 +34,8 @@ func main() {
var i I
var pi *I1
var pt *T1
var t T
var v Val
if s.val() != 1 {
println("s.val:", s.val())
@ -75,7 +77,10 @@ func main() {
println("(*I1).val(pi):", (*I1).val(pi))
panic("fail")
}
// if t.val() != 7 { prinln("t.val:", t.val()); panic("fail") }
if t.val() != 7 {
println("t.val:", t.val())
panic("fail")
}
if pt.val() != 8 {
println("pt.val:", pt.val())
panic("fail")
@ -101,11 +106,27 @@ func main() {
println("pi.val:", val(pi))
panic("fail")
}
// if val(t) != 7 { println("t.val:", val(t)); panic("fail") }
if val(t) != 7 {
println("t.val:", val(t))
panic("fail")
}
if val(pt) != 8 {
println("pt.val:", val(pt))
panic("fail")
}
// if Val.val(i) != 3 { println("Val.val(i):", Val.val(i)); panic("fail") }
if Val.val(i) != 3 {
println("Val.val(i):", Val.val(i))
panic("fail")
}
v = i
if Val.val(v) != 3 {
println("Val.val(v):", Val.val(v))
panic("fail")
}
pv := &v
if pv.val() != 3 {
println("pv.val():", pv.val())
panic("fail")
}
}

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@ -6,9 +6,17 @@
package main
type T struct {a int}
type T struct {
a int
}
type P *T
type P1 *T
func (p P) val() int { return 1 } // ERROR "receiver"
func (p *P1) val() int { return 1 } // ERROR "receiver"
func (p P) val() int { return 1 } // ERROR "receiver"
func (p *P1) val() int { return 1 } // ERROR "receiver"
type Val interface {
val() int
}
var _ = (*Val).val // ERROR "method"