Repository: go
Issue: cmd/vet: "possible misuse of unsafe.Pointer" check false positive rate may be too high
Labels: NeedsInvestigation,Analysis

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### What version of Go are you using (`go version`)?

<pre>
$ go version
go version go1.15 darwin/amd64
</pre>

### Does this issue reproduce with the latest release?



### What operating system and processor architecture are you using (`go env`)?

<details><summary><code>go env</code> Output</summary><br><pre>
$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/hajimehoshi/Library/Caches/go-build"
GOENV="/Users/hajimehoshi/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/hajimehoshi/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/hajimehoshi/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/hajimehoshi/ebiten/go.mod"
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/60/khbk2xqn1c5bml1byjn89dwc0000gn/T/go-build111042416=/tmp/go-build -gno-record-gcc-switches -fno-common"
</pre></details>

### What did you do?

<!--
If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.
-->

```
mkdir tmp
cd tmp
go mod init foo
GOOS=windows go vet golang.org/x/sys/windows
```

### What did you expect to see?

No warnings

### What did you see instead?

```
$ GOOS=windows go vet golang.org/x/sys/windows
go: finding module for package golang.org/x/sys/windows
go: found golang.org/x/sys/windows in golang.org/x/sys v0.0.0-20200831180312-196b9ba8737a
# golang.org/x/sys/windows
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/env_windows.go:42:39: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:1412:19: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:1547:18: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:1553:32: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:1809:27: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:1863:27: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3114:17: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3141:17: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3169:18: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3453:40: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3459:19: possible misuse of unsafe.Pointer
../go/pkg/mod/golang.org/x/sys@v0.0.0-20200831180312-196b9ba8737a/windows/zsyscall_windows.go:3465:27: possible misuse of unsafe.Pointer
```