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go/test/notinheap2.go
Keith Randall 22053790fa cmd/compile: propagate go:notinheap implicitly
//go:notinheap
type T int

type U T

We already correctly propagate the notinheap-ness of T to U.  But we
have an assertion in the typechecker that if there's no explicit
//go:notinheap associated with U, then report an error. Get rid of
that error so that implicit propagation is allowed.

Adjust the tests so that we make sure that uses of types like U
do correctly report an error when U is used in a context that might
cause a Go heap allocation.

Fixes #41451

Update #40954
Update #41432

Change-Id: I1692bc7cceff21ebb3f557f3748812a40887118d
Reviewed-on: https://go-review.googlesource.com/c/go/+/255637
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-09-17 19:35:53 +00:00

82 lines
1.8 KiB
Go

// errorcheck -+
// Copyright 2016 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.
// Test walk errors for go:notinheap.
package p
//go:notinheap
type nih struct {
next *nih
}
// Global variables are okay.
var x nih
// Stack variables are not okay.
func f() {
var y nih // ERROR "nih is incomplete \(or unallocatable\); stack allocation disallowed"
x = y
}
// Heap allocation is not okay.
var y *nih
var y2 *struct{ x nih }
var y3 *[1]nih
var z []nih
var w []nih
var n int
var sink interface{}
type embed1 struct { // implicitly notinheap
x nih
}
type embed2 [1]nih // implicitly notinheap
type embed3 struct { // implicitly notinheap
x [1]nih
}
// Type aliases inherit the go:notinheap-ness of the type they alias.
type nihAlias = nih
type embedAlias1 struct { // implicitly notinheap
x nihAlias
}
type embedAlias2 [1]nihAlias // implicitly notinheap
func g() {
y = new(nih) // ERROR "can't be allocated in Go"
y2 = new(struct{ x nih }) // ERROR "can't be allocated in Go"
y3 = new([1]nih) // ERROR "can't be allocated in Go"
z = make([]nih, 1) // ERROR "can't be allocated in Go"
z = append(z, x) // ERROR "can't be allocated in Go"
sink = new(embed1) // ERROR "can't be allocated in Go"
sink = new(embed2) // ERROR "can't be allocated in Go"
sink = new(embed3) // ERROR "can't be allocated in Go"
sink = new(embedAlias1) // ERROR "can't be allocated in Go"
sink = new(embedAlias2) // ERROR "can't be allocated in Go"
// Test for special case of OMAKESLICECOPY
x := make([]nih, n) // ERROR "can't be allocated in Go"
copy(x, z)
z = x
}
// Writes don't produce write barriers.
var p *nih
//go:nowritebarrier
func h() {
y.next = p.next
}