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interp: fix and refactor typeAssertStatus in

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typeAssertStatus deals with the 3rd form of type assertion ("_, ok"), for
when one does not care about the result of the assertion itself.
Some cases for it, which are already fixed for the two other forms of
type assertions, had not been fixed for this form yet.

Therefore, this change fixes such cases for this form, while integrating
typeAssertStatus to the same code path as for the two other forms.
This commit is contained in:
mpl
2020-12-07 15:58:04 +01:00
committed by GitHub
parent 92d65c22f0
commit 662838fd80
4 changed files with 92 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
_test/assert0.go
View File

@@ -48,6 +48,14 @@ func main() {
bType := reflect.TypeOf(TestStruct{})
fmt.Println(bType.Implements(aType))
// not redundant with the above, because it goes through a slightly different code path.
if _, ok := t.(MyWriter); !ok {
fmt.Println("TestStruct does not implement MyWriter")
return
} else {
fmt.Println("TestStruct implements MyWriter")
}
t = 42
foo, ok := t.(MyWriter)
if !ok {
@@ -57,6 +65,12 @@ func main() {
}
_ = foo
if _, ok := t.(MyWriter); !ok {
fmt.Println("42 does not implement MyWriter")
} else {
fmt.Println("42 implements MyWriter")
}
var tt interface{}
tt = time.Nanosecond
var myD MyStringer
@@ -72,6 +86,12 @@ func main() {
dType := reflect.TypeOf(time.Nanosecond)
fmt.Println(dType.Implements(cType))
if _, ok := tt.(MyStringer); !ok {
fmt.Println("time.Nanosecond does not implement MyStringer")
} else {
fmt.Println("time.Nanosecond implements MyStringer")
}
tt = 42
bar, ok := tt.(MyStringer)
if !ok {
@@ -81,6 +101,11 @@ func main() {
}
_ = bar
if _, ok := tt.(MyStringer); !ok {
fmt.Println("42 does not implement MyStringer")
} else {
fmt.Println("42 implements MyStringer")
}
}
// Output:
@@ -88,9 +113,13 @@ func main() {
// 11
// 11
// true
// TestStruct implements MyWriter
// 42 does not implement MyWriter
// 42 does not implement MyWriter
// time.Nanosecond implements MyStringer
// 1ns
// 1ns
// true
// time.Nanosecond implements MyStringer
// 42 does not implement MyStringer
// 42 does not implement MyStringer

25
_test/assert1.go
View File

@@ -27,6 +27,13 @@ func main() {
bType := reflect.TypeOf(time.Nanosecond)
fmt.Println(bType.Implements(aType))
// not redundant with the above, because it goes through a slightly different code path.
if _, ok := t.(fmt.Stringer); !ok {
fmt.Println("time.Nanosecond does not implement fmt.Stringer")
return
} else {
fmt.Println("time.Nanosecond implements fmt.Stringer")
}
t = 42
foo, ok := t.(fmt.Stringer)
@@ -34,9 +41,17 @@ func main() {
fmt.Println("42 does not implement fmt.Stringer")
} else {
fmt.Println("42 implements fmt.Stringer")
return
}
_ = foo
if _, ok := t.(fmt.Stringer); !ok {
fmt.Println("42 does not implement fmt.Stringer")
} else {
fmt.Println("42 implements fmt.Stringer")
return
}
var tt interface{}
tt = TestStruct{}
ss, ok := tt.(fmt.Stringer)
@@ -49,12 +64,22 @@ func main() {
// TODO(mpl): uncomment when fixed
// cType := reflect.TypeOf(TestStruct{})
// fmt.Println(cType.Implements(aType))
if _, ok := tt.(fmt.Stringer); !ok {
fmt.Println("TestStuct does not implement fmt.Stringer")
return
} else {
fmt.Println("TestStuct implements fmt.Stringer")
}
}
// Output:
// 1ns
// 1ns
// true
// time.Nanosecond implements fmt.Stringer
// 42 does not implement fmt.Stringer
// 42 does not implement fmt.Stringer
// hello world
// hello world
// TestStuct implements fmt.Stringer

4
interp/cfg.go
View File

@@ -648,7 +648,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
if n.child[0].ident == "_" {
lc.gen = typeAssertStatus
} else {
lc.gen = typeAssert2
lc.gen = typeAssertLong
}
n.gen = nop
case unaryExpr:
@@ -1903,7 +1903,7 @@ func compDefineX(sc *scope, n *node) error {
if n.child[0].ident == "_" {
n.child[l].gen = typeAssertStatus
} else {
n.child[l].gen = typeAssert2
n.child[l].gen = typeAssertLong
}
types = append(types, n.child[l].child[1].typ, sc.getType("bool"))
n.gen = nop

86
interp/run.go
View File

@@ -69,7 +69,7 @@ var builtin = [...]bltnGenerator{
aStar: deref,
aSub: sub,
aSubAssign: subAssign,
aTypeAssert: typeAssert1,
aTypeAssert: typeAssertShort,
aXor: xor,
aXorAssign: xorAssign,
}
@@ -191,45 +191,6 @@ func runCfg(n *node, f *frame) {
}
}
func typeAssertStatus(n *node) {
c0, c1 := n.child[0], n.child[1] // cO contains the input value, c1 the type to assert
value := genValue(c0) // input value
value1 := genValue(n.anc.child[1]) // returned status
rtype := c1.typ.rtype // type to assert
next := getExec(n.tnext)
switch {
case isInterfaceSrc(c1.typ):
typ := c1.typ
n.exec = func(f *frame) bltn {
v, ok := value(f).Interface().(valueInterface)
value1(f).SetBool(ok && v.node.typ.implements(typ))
return next
}
case isInterface(c1.typ):
n.exec = func(f *frame) bltn {
v := value(f)
ok := v.IsValid() && canAssertTypes(v.Elem().Type(), rtype)
value1(f).SetBool(ok)
return next
}
case c0.typ.cat == valueT || c0.typ.cat == errorT:
n.exec = func(f *frame) bltn {
v := value(f)
ok := v.IsValid() && canAssertTypes(v.Elem().Type(), rtype)
value1(f).SetBool(ok)
return next
}
default:
n.exec = func(f *frame) bltn {
v, ok := value(f).Interface().(valueInterface)
ok = ok && v.value.IsValid() && canAssertTypes(v.value.Type(), rtype)
value1(f).SetBool(ok)
return next
}
}
}
func stripReceiverFromArgs(signature string) (string, error) {
fields := receiverStripperRxp.FindStringSubmatch(signature)
if len(fields) < 5 {
@@ -241,25 +202,33 @@ func stripReceiverFromArgs(signature string) (string, error) {
return fmt.Sprintf("func(%s", fields[4]), nil
}
func typeAssert1(n *node) {
typeAssert(n, false)
func typeAssertShort(n *node) {
typeAssert(n, true, false)
}
func typeAssert2(n *node) {
typeAssert(n, true)
func typeAssertLong(n *node) {
typeAssert(n, true, true)
}
func typeAssert(n *node, withOk bool) {
func typeAssertStatus(n *node) {
typeAssert(n, false, true)
}
func typeAssert(n *node, withResult, withOk bool) {
c0, c1 := n.child[0], n.child[1]
value := genValue(c0) // input value
var value0, value1 func(*frame) reflect.Value
setStatus := false
if withOk {
switch {
case withResult && withOk:
value0 = genValue(n.anc.child[0]) // returned result
value1 = genValue(n.anc.child[1]) // returned status
setStatus = n.anc.child[1].ident != "_" // do not assign status to "_"
} else {
case withResult && !withOk:
value0 = genValue(n) // returned result
case !withResult && withOk:
value1 = genValue(n.anc.child[1]) // returned status
setStatus = n.anc.child[1].ident != "_" // do not assign status to "_"
}
typ := c1.typ // type to assert or convert to
@@ -270,7 +239,8 @@ func typeAssert(n *node, withOk bool) {
switch {
case isInterfaceSrc(typ):
n.exec = func(f *frame) bltn {
v, ok := value(f).Interface().(valueInterface)
valf := value(f)
v, ok := valf.Interface().(valueInterface)
if setStatus {
defer func() {
value1(f).SetBool(ok)
@@ -283,7 +253,9 @@ func typeAssert(n *node, withOk bool) {
return next
}
if v.node.typ.id() == typID {
value0(f).Set(value(f))
if withResult {
value0(f).Set(valf)
}
return next
}
m0 := v.node.typ.methods()
@@ -329,7 +301,9 @@ func typeAssert(n *node, withOk bool) {
}
}
value0(f).Set(value(f))
if withResult {
value0(f).Set(valf)
}
return next
}
case isInterface(typ):
@@ -362,9 +336,9 @@ func typeAssert(n *node, withOk bool) {
}
}
// TODO(mpl): make this case compliant with reflect's Implements.
v = genInterfaceWrapper(val.node, rtype)(f)
value0(f).Set(v)
if withResult {
value0(f).Set(genInterfaceWrapper(val.node, rtype)(f))
}
ok = true
return next
}
@@ -392,7 +366,9 @@ func typeAssert(n *node, withOk bool) {
}
return next
}
if withResult {
value0(f).Set(v)
}
return next
}
case n.child[0].typ.cat == valueT || n.child[0].typ.cat == errorT:
@@ -418,7 +394,9 @@ func typeAssert(n *node, withOk bool) {
}
return next
}
if withResult {
value0(f).Set(v)
}
return next
}
default:
@@ -443,7 +421,9 @@ func typeAssert(n *node, withOk bool) {
}
return next
}
if withResult {
value0(f).Set(v.value)
}
return next
}
}