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7904946eeb
In order to fix issue #9401 the compiler was changed to add a padding byte to any non-empty Go struct that ends in a zero-sized field. That causes the Go version of such a C struct to have a different size than the C struct, which can considerable confusion. Change cgo so that it discards any such zero-sized fields, so that the Go and C structs are the same size. This is a change from previous releases, in that it used to be possible to refer to a zero-sized trailing field (by taking its address), and with this change it no longer is. That is unfortunate, but something has to change. It seems better to visibly break programs that do this rather than to silently break programs that rely on the struct sizes being the same. Update #9401. Fixes #11925. Change-Id: I3fba3f02f11265b3c41d68616f79dedb05b81225 Reviewed-on: https://go-review.googlesource.com/12864 Reviewed-by: Russ Cox <rsc@golang.org>
56 lines
1.0 KiB
Go
56 lines
1.0 KiB
Go
// Copyright 2014 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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// This test fails on older versions of OS X because they use older buggy
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// versions of Clang that emit ambiguous DWARF info. See issue 8611.
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// +build !darwin
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package cgotest
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// Issue 8428. Cgo inconsistently translated zero size arrays.
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/*
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struct issue8428one {
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char b;
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char rest[];
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};
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struct issue8428two {
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void *p;
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char b;
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char rest[0];
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char pad;
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};
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struct issue8428three {
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char w[1][2][3][0];
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char x[2][3][0][1];
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char y[3][0][1][2];
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char z[0][1][2][3];
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};
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*/
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import "C"
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import "unsafe"
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var _ = C.struct_issue8428one{
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b: C.char(0),
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// The trailing rest field is not available in cgo.
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// See issue 11925.
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// rest: [0]C.char{},
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}
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var _ = C.struct_issue8428two{
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p: unsafe.Pointer(nil),
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b: C.char(0),
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rest: [0]C.char{},
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}
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var _ = C.struct_issue8428three{
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w: [1][2][3][0]C.char{},
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x: [2][3][0][1]C.char{},
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y: [3][0][1][2]C.char{},
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z: [0][1][2][3]C.char{},
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}
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