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a9e6cebde2
This pragma cancels the effect of go:nowritebarrierrec. This is useful in the scheduler because there are places where we enter a function without a valid P (and hence cannot have write barriers), but then obtain a P. This allows us to annotate the function with go:nowritebarrierrec and split out the part after we've obtained a P into a go:yeswritebarrierrec function. Change-Id: Ic8ce4b6d3c074a1ecd8280ad90eaf39f0ffbcc2a Reviewed-on: https://go-review.googlesource.com/30938 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Keith Randall <khr@golang.org>
79 lines
974 B
Go
79 lines
974 B
Go
// errorcheck -+
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// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Test go:nowritebarrier and related directives.
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package p
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type t struct {
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f *t
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}
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var x t
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var y *t
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//go:nowritebarrier
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func a1() {
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x.f = y // ERROR "write barrier prohibited"
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a2() // no error
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}
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//go:noinline
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func a2() {
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x.f = y
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}
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//go:nowritebarrierrec
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func b1() {
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b2()
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}
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//go:noinline
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func b2() {
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x.f = y // ERROR "write barrier prohibited by caller"
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}
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// Test recursive cycles through nowritebarrierrec and yeswritebarrierrec.
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//go:nowritebarrierrec
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func c1() {
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c2()
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}
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//go:yeswritebarrierrec
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func c2() {
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c3()
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}
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func c3() {
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x.f = y
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c4()
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}
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//go:nowritebarrierrec
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func c4() {
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c2()
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}
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//go:nowritebarrierrec
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func d1() {
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d2()
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}
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func d2() {
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d3()
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}
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func d3() {
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x.f = y // ERROR "write barrier prohibited by caller"
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d4()
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}
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//go:yeswritebarrierrec
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func d4() {
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d2()
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}
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