[dev.typeparams] go/types: implement close(ch) where ch is of type parameter type

This is a port of CL 333713 to go/types.

Change-Id: I517f52592f65cc76e11a12d9148b20c12d9e3e81
Reviewed-on: https://go-review.googlesource.com/c/go/+/335077
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

diff --git a/src/go/types/builtins.go b/src/go/types/builtins.go
index 2573bac69ec6bd78f91a11ce0c1f773ba36e1c31..c8348f425917d06b1916a675177dccbd1feab29d 100644 (file)
--- a/src/go/types/builtins.go
+++ b/src/go/types/builtins.go
@@ -217,19 +217,23 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 
        case _Close:
                // close(c)
-               c := asChan(x.typ)
-               if c == nil {
-                       check.invalidArg(x, _InvalidClose, "%s is not a channel", x)
-                       return
-               }
-               if c.dir == RecvOnly {
-                       check.invalidArg(x, _InvalidClose, "%s must not be a receive-only channel", x)
+               if !underIs(x.typ, func(u Type) bool {
+                       uch, _ := u.(*Chan)
+                       if uch == nil {
+                               check.invalidOp(x, _InvalidClose, "cannot close non-channel %s", x)
+                               return false
+                       }
+                       if uch.dir == RecvOnly {
+                               check.invalidOp(x, _InvalidClose, "cannot close receive-only channel %s", x)
+                               return false
+                       }
+                       return true
+               }) {
                        return
                }
-
                x.mode = novalue
                if check.Types != nil {
-                       check.recordBuiltinType(call.Fun, makeSig(nil, c))
+                       check.recordBuiltinType(call.Fun, makeSig(nil, x.typ))
                }
 
        case _Complex:

diff --git a/src/go/types/testdata/check/builtins.go2 b/src/go/types/testdata/check/builtins.go2
index 5bb67efec9d429d201d95b27fc5136b82f560f56..71295bf4342f78cdfcc0bd2420fce85e250b992a 100644 (file)
--- a/src/go/types/testdata/check/builtins.go2
+++ b/src/go/types/testdata/check/builtins.go2
@@ -6,6 +6,45 @@
 
 package builtins
 
+// close
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func _[T any](ch T) {
+       close(ch /* ERROR cannot close non-channel */)
+}
+
+func _[T C0](ch T) {
+       close(ch /* ERROR cannot close non-channel */)
+}
+
+func _[T C1](ch T) {
+       close(ch)
+}
+
+func _[T C2](ch T) {
+       close(ch /* ERROR cannot close receive-only channel */)
+}
+
+func _[T C3](ch T) {
+       close(ch)
+}
+
+func _[T C4](ch T) {
+       close(ch)
+}
+
+func _[T C5[X], X any](ch T) {
+       close(ch)
+}
+
+// make
+
 type Bmc interface {
        ~map[rune]string | ~chan int
 }
@@ -22,31 +61,31 @@ type Bss interface {
        ~[]int | ~[]string
 }
 
-func _[T any] () {
-       _ = make(T /* ERROR invalid argument */ )
-       _ = make(T /* ERROR invalid argument */ , 10)
-       _ = make(T /* ERROR invalid argument */ , 10, 20)
+func _[T any]() {
+       _ = make(T /* ERROR invalid argument */)
+       _ = make(T /* ERROR invalid argument */, 10)
+       _ = make(T /* ERROR invalid argument */, 10, 20)
 }
 
-func _[T Bmc] () {
+func _[T Bmc]() {
        _ = make(T)
        _ = make(T, 10)
        _ = make /* ERROR expects 1 or 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bms] () {
+func _[T Bms]() {
        _ = make /* ERROR expects 2 arguments */ (T)
        _ = make(T, 10)
        _ = make /* ERROR expects 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bcs] () {
+func _[T Bcs]() {
        _ = make /* ERROR expects 2 arguments */ (T)
        _ = make(T, 10)
        _ = make /* ERROR expects 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bss] () {
+func _[T Bss]() {
        _ = make /* ERROR expects 2 or 3 arguments */ (T)
        _ = make(T, 10)
        _ = make(T, 10, 20)

diff --git a/src/go/types/testdata/check/builtins.src b/src/go/types/testdata/check/builtins.src
index 370752891407beef0f7d828a128144617c4796c9..7fd6a4b03297ba2385f4e62ba4aecd450834c337 100644 (file)
--- a/src/go/types/testdata/check/builtins.src
+++ b/src/go/types/testdata/check/builtins.src
@@ -144,7 +144,7 @@ func close1() {
        var r <-chan int
        close() // ERROR not enough arguments
        close(1, 2) // ERROR too many arguments
-       close(42 /* ERROR not a channel */)
+       close(42 /* ERROR cannot close non-channel */)
        close(r /* ERROR receive-only channel */)
        close(c)
        _ = close /* ERROR used as value */ (c)

diff --git a/src/go/types/type.go b/src/go/types/type.go
index e0498fece2689b8e9cf941784d215f224e8a7a5c..bbb7100ef4f6b639a67cf177e4dd35006b15ab67 100644 (file)
--- a/src/go/types/type.go
+++ b/src/go/types/type.go
@@ -105,11 +105,6 @@ func asPointer(t Type) *Pointer {
        return op
 }
 
-func asTuple(t Type) *Tuple {
-       op, _ := optype(t).(*Tuple)
-       return op
-}
-
 func asSignature(t Type) *Signature {
        op, _ := optype(t).(*Signature)
        return op
@@ -120,11 +115,6 @@ func asMap(t Type) *Map {
        return op
 }
 
-func asChan(t Type) *Chan {
-       op, _ := optype(t).(*Chan)
-       return op
-}
-
 // If the argument to asInterface, asNamed, or asTypeParam is of the respective type
 // (possibly after expanding an instance type), these methods return that type.
 // Otherwise the result is nil.