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x/sys: cacheLineSize redeclared in this block #30668
Description
What version of Go are you using (go version)?
$ go version go version go1.10.7 darwin/amd64
Does this issue reproduce with the latest release?
No, haven't tested (development is done with 1.10.7)
What operating system and processor architecture are you using (go env)?
go env Output
λ ~/go/src/golang.org/x/sys (master): go env GOARCH="amd64" GOBIN="/Users/tristian/go/bin" GOCACHE="/Users/tristian/Library/Caches/go-build" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/tristian/go" GORACE="" GOROOT="/usr/local/Cellar/go@1.10/1.10.7/libexec" GOTMPDIR="" GOTOOLDIR="/usr/local/Cellar/go@1.10/1.10.7/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" CC="clang" CXX="clang++" CGO_ENABLED="1" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/g1/v3hz1sm92nv7wbzpg3dx_h_h0000gp/T/go-build319213198=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
I just ran go get golang.org/x/sys and ran go build ./...
The commit I checked out was:
commit 572b51eaf7221935bdec454796989ba8318fa6f3 (HEAD -> master, origin/master, origin/HEAD)
Author: Tobias Klauser <tklauser@distanz.ch>
Date: Thu Mar 7 14:06:33 2019 +0100
unix: add SetsockoptPacketMreq on Linux
Add SetsockoptPacketMreq to set packet socket options used to
configure physical-layer multi‐casting and promiscuous mode
(PACKET_ADD_MEMBERSHIP, PACKET_DROP_MEMBERSHIP).
Change-Id: I0f292315ad1c57e6a3d1dd12f5f29be70d8bfd54
Reviewed-on: https://go-review.googlesource.com/c/sys/+/165977
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
And it seems like the wasm constant that is redeclared was instruduced in commit b354f8bf
λ ~/go/src/golang.org/x/sys (master): git blame cpu/cpu_wasm.go
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 1) // Copyright 2019 The Go Authors. All rights reserved.
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 2) // Use of this source code is governed by a BSD-style
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 3) // license that can be found in the LICENSE file.
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 4)
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 5) package cpu
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 6)
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 7) // We're compiling the cpu package for an unknown (software-abstracted) CPU.
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 8) // Make CacheLinePad an empty struct and hope that the usual struct alignment
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 9) // rules are good enough.
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 10)
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 11) const cacheLineSize = 0
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 12)
b354f8bf (Bryan C. Mills 2019-03-06 16:31:30 -0500 13) func doinit() {}
What did you expect to see?
No output; a succesful build
What did you see instead?
Build failed with the following output:
$ ~/go/src/golang.org/x/sys (master): go build ./...
# golang.org/x/sys/cpu
cpu/cpu_x86.go:9:23: cacheLineSize redeclared in this block
previous declaration at cpu/cpu_wasm.go:11:23
Activity
ianlancetaylor commentedon Mar 8, 2019
This is happening because Go 1.10 doesn't know about wasm. Will send a CL.
triztian commentedon Mar 8, 2019
Awesome, thank you for the quick reply!!, seems like adding the
Build tag to the
cpu/cpu_wasm.gofixes the issue. Is that the correct way to fix it?ianlancetaylor commentedon Mar 8, 2019
Yes. I sent https://golang.org/cl/166137.
gopherbot commentedon Mar 8, 2019
Change https://golang.org/cl/166137 mentions this issue:
cpu: add build tag to cpu_wasm.gocpu: add build tag to cpu_wasm.go