x/tools/go/analysis/passes/{nilness,unusedwrite,buildssa}: some go vet analyzers don't work with generics.

[ldez]

What version of Go are you using (go version)?

$ go version 
go version go1.18beta2 linux/amd64

Does this issue reproduce with the latest release?

It's related to generics.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/ldez/.cache/go-build"
GOENV="/home/ldez/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/ldez/sources/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/ldez/sources/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/ldez/.gvm/gos/go1.18beta2"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/ldez/.gvm/gos/go1.18beta2/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.18beta2"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
GOWORK=""
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build2068066531=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I use the following analyzers:

• nilness
• unusedwrite
• buildssa

These 3 analyzers are related to the support of generics in the SSA package #48525.

Related to #48704 and #50558

What did you expect to see?

No panic.

What did you see instead?

ERRO [runner] Panic: unusedwrite: package "sandbox" (isInitialPkg: true, needAnalyzeSource: true): interface conversion: interface {} is nil, not *buildssa.SSA: goroutine 896 [running]:
runtime/debug.Stack()
        runtime/debug/stack.go:24 +0x65
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe.func1()
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:101 +0x155
panic({0x134e7c0, 0xc000886810})
        runtime/panic.go:838 +0x207
golang.org/x/tools/go/analysis/passes/unusedwrite.run(0x13307c0?)
        golang.org/x/tools@v0.1.9/go/analysis/passes/unusedwrite/unusedwrite.go:74 +0x166
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyze(0xc000b256c0)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:187 +0x9c4
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe.func2()
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:105 +0x1d
github.com/golangci/golangci-lint/pkg/timeutils.(*Stopwatch).TrackStage(0xc000210280, {0x14b92e6, 0xb}, 0xc00069d748)
        github.com/golangci/golangci-lint/pkg/timeutils/stopwatch.go:111 +0x4a
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe(0xc00112af00?)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:104 +0x85
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*loadingPackage).analyze.func2(0xc000b256c0)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_loadingpackage.go:80 +0xb4
created by github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*loadingPackage).analyze
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_loadingpackage.go:75 +0x1eb

ERRO [runner] Panic: nilness: package "sandbox" (isInitialPkg: true, needAnalyzeSource: true): interface conversion: interface {} is nil, not *buildssa.SSA: goroutine 949 [running]:
runtime/debug.Stack()
        runtime/debug/stack.go:24 +0x65
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe.func1()
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:101 +0x155
panic({0x134e7c0, 0xc000c5e060})
        runtime/panic.go:838 +0x207
golang.org/x/tools/go/analysis/passes/nilness.run(0xc00245e270)
        golang.org/x/tools@v0.1.9/go/analysis/passes/nilness/nilness.go:64 +0xad
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyze(0xc0016d6a50)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:187 +0x9c4
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe.func2()
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:105 +0x1d
github.com/golangci/golangci-lint/pkg/timeutils.(*Stopwatch).TrackStage(0xc000586820, {0x146d160, 0x7}, 0xc00179cf48)
        github.com/golangci/golangci-lint/pkg/timeutils/stopwatch.go:111 +0x4a
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*action).analyzeSafe(0xc000251980?)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_action.go:104 +0x85
github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*loadingPackage).analyze.func2(0xc0016d6a50)
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_loadingpackage.go:80 +0xb4
created by github.com/golangci/golangci-lint/pkg/golinters/goanalysis.(*loadingPackage).analyze
        github.com/golangci/golangci-lint/pkg/golinters/goanalysis/runner_loadingpackage.go:75 +0x1eb 

[dominikh]

I would consider this a duplicate of #48525. Do you agree?

[ldez]

The problem is related to x/tools/go/ssa but nilness, unusedwrite are not in the package x/tools/go/ssa.
So I don't know what is the best approach to track this.
If you think that #48525 is enough, you can consider this issue as a duplicate.

[timothy-king]

IMO this is a duplicate of #48525.