[dev.typeparams] go/types: implement ch <- x where ch is of type parameter type

This is a port of CL 333712 to go/types, adjusted for the different
error reporting API and to position errors on the arrows.

Fixes #43671

Change-Id: I7d2de249e86d272c89a046f60e632e75848ff865
Reviewed-on: https://go-review.googlesource.com/c/go/+/335076
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>
This commit is contained in:
Rob Findley 2021-07-16 20:22:59 -04:00 committed by Robert Findley
parent d6d7f8458e
commit 19b4142f24
2 changed files with 62 additions and 14 deletions

View file

@ -361,25 +361,33 @@ func (check *Checker) stmt(ctxt stmtContext, s ast.Stmt) {
check.errorf(&x, code, "%s %s", &x, msg) check.errorf(&x, code, "%s %s", &x, msg)
case *ast.SendStmt: case *ast.SendStmt:
var ch, x operand var ch, val operand
check.expr(&ch, s.Chan) check.expr(&ch, s.Chan)
check.expr(&x, s.Value) check.expr(&val, s.Value)
if ch.mode == invalid || x.mode == invalid { if ch.mode == invalid || val.mode == invalid {
return return
} }
var elem Type
tch := asChan(ch.typ) if !underIs(ch.typ, func(u Type) bool {
if tch == nil { uch, _ := u.(*Chan)
check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to non-chan type %s", ch.typ) if uch == nil {
check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to non-channel %s", &ch)
return false
}
if uch.dir == RecvOnly {
check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to receive-only channel %s", &ch)
return false
}
if elem != nil && !Identical(uch.elem, elem) {
check.invalidOp(inNode(s, s.Arrow), _Todo, "channels of %s must have the same element type", &ch)
return false
}
elem = uch.elem
return true
}) {
return return
} }
check.assignment(&val, elem, "send")
if tch.dir == RecvOnly {
check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to receive-only type %s", tch)
return
}
check.assignment(&x, tch.elem, "send")
case *ast.IncDecStmt: case *ast.IncDecStmt:
var op token.Token var op token.Token

View file

@ -0,0 +1,40 @@
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package p
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) {
ch <- /* ERROR cannot send to non-channel */ 0
}
func _[T C0](ch T) {
ch <- /* ERROR cannot send to non-channel */ 0
}
func _[T C1](ch T) {
ch <- 0
}
func _[T C2](ch T) {
ch <-/* ERROR cannot send to receive-only channel */ 0
}
func _[T C3](ch T) {
ch <- /* ERROR channels of ch .* must have the same element type */ 0
}
func _[T C4](ch T) {
ch <- 0
}
func _[T C5[X], X any](ch T, x X) {
ch <- x
}