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author | Keith Randall <keithr@alum.mit.edu> | 2019-06-13 19:11:25 -0700 |
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committer | Keith Randall <khr@golang.org> | 2019-06-25 21:30:39 +0000 |
commit | 343b7fa6261a5b0ceaafed535438249ffa5686de (patch) | |
tree | 2cf02ce735c5aadc59079fbdbfc762855140e486 | |
parent | 8382ccb0bcc57b5d4240bb662bc1e68c5d921b4c (diff) | |
download | go-343b7fa6261a5b0ceaafed535438249ffa5686de.tar.gz go-343b7fa6261a5b0ceaafed535438249ffa5686de.zip |
cmd/compile: don't mark argument array as noalg
It ends up making two similar types, [N]uint8 of both
alg and noalg varieties. Comparsions between the two then
don't come out equal when they should.
In particular, the type *[N]uint8 has an Elem pointer which
must point to one of the above two types; it can't point to both.
Thus allocating a *[N]uint8 and dereferencing it might be a
different type than a [N]uint8.
The fix is easy. Making a small test for this is really hard. It
requires that both a argless defer and the test be imported by a
common parent package. This is why a main binary doesn't see this
issue, but a test does (as Agniva noticed), because there's a wrapper
package that imports both the test and the defer.
Types like [N]uint8 don't really need to be marked noalg anyway,
as the generated code (if any) will be shared among all
vanilla memory types of the same size.
Fixes #32595
Change-Id: If7b77fa6ed56cd4495601c3f90170682d853b82f
Reviewed-on: https://go-review.googlesource.com/c/go/+/182357
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
-rw-r--r-- | src/cmd/compile/internal/gc/reflect.go | 1 | ||||
-rw-r--r-- | test/fixedbugs/issue32595.dir/a.go | 9 | ||||
-rw-r--r-- | test/fixedbugs/issue32595.dir/b.go | 15 | ||||
-rw-r--r-- | test/fixedbugs/issue32595.dir/main.go | 15 | ||||
-rw-r--r-- | test/fixedbugs/issue32595.go | 7 |
5 files changed, 46 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/reflect.go b/src/cmd/compile/internal/gc/reflect.go index 0854817713..9b26ba16cb 100644 --- a/src/cmd/compile/internal/gc/reflect.go +++ b/src/cmd/compile/internal/gc/reflect.go @@ -330,7 +330,6 @@ func deferstruct(stksize int64) *types.Type { return f } argtype := types.NewArray(types.Types[TUINT8], stksize) - argtype.SetNoalg(true) argtype.Width = stksize argtype.Align = 1 // These fields must match the ones in runtime/runtime2.go:_defer and diff --git a/test/fixedbugs/issue32595.dir/a.go b/test/fixedbugs/issue32595.dir/a.go new file mode 100644 index 0000000000..8342dd5cbc --- /dev/null +++ b/test/fixedbugs/issue32595.dir/a.go @@ -0,0 +1,9 @@ +// Copyright 2019 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 a + +func A() { + defer func() {}() +} diff --git a/test/fixedbugs/issue32595.dir/b.go b/test/fixedbugs/issue32595.dir/b.go new file mode 100644 index 0000000000..9a13a575a8 --- /dev/null +++ b/test/fixedbugs/issue32595.dir/b.go @@ -0,0 +1,15 @@ +// Copyright 2019 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 b + +import "reflect" + +func B() { + t1 := reflect.TypeOf([0]byte{}) + t2 := reflect.TypeOf(new([0]byte)).Elem() + if t1 != t2 { + panic("[0]byte types do not match") + } +} diff --git a/test/fixedbugs/issue32595.dir/main.go b/test/fixedbugs/issue32595.dir/main.go new file mode 100644 index 0000000000..20472cd72a --- /dev/null +++ b/test/fixedbugs/issue32595.dir/main.go @@ -0,0 +1,15 @@ +// Copyright 2019 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 main + +import ( + "a" + "b" +) + +func main() { + a.A() + b.B() +} diff --git a/test/fixedbugs/issue32595.go b/test/fixedbugs/issue32595.go new file mode 100644 index 0000000000..af6f134172 --- /dev/null +++ b/test/fixedbugs/issue32595.go @@ -0,0 +1,7 @@ +// rundir + +// Copyright 2019 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 ignored |