panic with generics

[ldez]

The following code produces a panic:

func Drain[T <-chan E | chan E, E any](c T) {
	if c == nil {
		return
	}
	for range c {
	}
}

$ staticcheck ./...                                                    
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x6d2e4a]

goroutine 370 [running]:
honnef.co/go/tools/go/ir.(*builder).rangeStmt(0xc000a62c80?, 0xc000a62c80, 0xc00033ba40, 0x0, {0x9d2718, 0xc00033ba40})
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2156 +0x34a
honnef.co/go/tools/go/ir.(*builder).stmt(0x40c53d?, 0xc000a62c80, {0x9d41f8?, 0xc00033ba40?})
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2380 +0x83e
honnef.co/go/tools/go/ir.(*builder).stmtList(0xc0006b3538?, 0x40e9a7?, {0xc0000db820?, 0x2, 0xc0006b3598?})
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:855 +0x67
honnef.co/go/tools/go/ir.(*builder).stmt(0xc000a62c80?, 0xc000a62c80, {0x9d3c88?, 0xc0005e1920?})
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2338 +0xd31
honnef.co/go/tools/go/ir.(*builder).buildFunction(0xc0006b3b00, 0xc000a62c80)
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2450 +0x453
honnef.co/go/tools/go/ir.(*builder).buildFuncDecl(0xc000738700?, 0xc000270e10, 0xc0005e19e0)
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2488 +0x195
honnef.co/go/tools/go/ir.(*Package).build(0xc000270e10)
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2594 +0xc52
sync.(*Once).doSlow(0xc0007380e0?, 0xc00033b900?)
        /home/ldez/.gvm/gos/go1.18.4/src/sync/once.go:68 +0xc2
sync.(*Once).Do(...)
        /home/ldez/.gvm/gos/go1.18.4/src/sync/once.go:59
honnef.co/go/tools/go/ir.(*Package).Build(...)
        /home/ldez/sources/golangci-lint/go-tools/go/ir/builder.go:2512
honnef.co/go/tools/internal/passes/buildir.run(0xc000112410)
        /home/ldez/sources/golangci-lint/go-tools/internal/passes/buildir/buildir.go:86 +0x368
honnef.co/go/tools/lintcmd/runner.(*analyzerRunner).do(0xc00075b1d0, {0x9d52b8?, 0xc0000c2f00})
        /home/ldez/sources/golangci-lint/go-tools/lintcmd/runner/runner.go:989 +0x614
honnef.co/go/tools/lintcmd/runner.genericHandle({0x9d52b8?, 0xc0000c2f00}, {0x9d52b8?, 0xc0000c2aa0?}, 0x0?, 0xc00040de00, 0xc00029ba70)
        /home/ldez/sources/golangci-lint/go-tools/lintcmd/runner/runner.go:814 +0x102
created by honnef.co/go/tools/lintcmd/runner.(*subrunner).runAnalyzers
        /home/ldez/sources/golangci-lint/go-tools/lintcmd/runner/runner.go:1058 +0x705

Tested with v0.3.2 and HEAD of master (555b2d3)

---

$ staticcheck -version
staticcheck 2022.1.2 (v0.3.2)

$ staticcheck -debug.version
staticcheck 2022.1.2 (v0.3.2)

Compiled with Go version: go1.18.4
Main module:
        honnef.co/go/tools
Dependencies:
        github.com/BurntSushi/toml@v0.4.1 (sum: h1:GaI7EiDXDRfa8VshkTj7Fym7ha+y8/XxIgD2okUIjLw=)
        golang.org/x/exp/typeparams@v0.0.0-20220218215828-6cf2b201936e (sum: h1:qyrTQ++p1afMkO4DPEeLGq/3oTsdlvdH4vqZUBWzUKM=)
        golang.org/x/mod@v0.6.0-dev.0.20220419223038-86c51ed26bb4 (sum: h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=)
        golang.org/x/sys@v0.0.0-20211019181941-9d821ace8654 (sum: h1:id054HUawV2/6IGm2IV8KZQjqtwAOo2CYlOToYqa0d0=)
        golang.org/x/tools@v0.1.11-0.20220513221640-090b14e8501f (sum: h1:OKYpQQVE3DKSc3r3zHVzq46vq5YH7x8xpR3/k9ixmUg=)

$ go version       
go version go1.18.4 linux/amd64

$ 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/go1.18.4"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/ldez/.gvm/gos/go1.18.4/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.18.4"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/ldez/sources/go/src/github.com/golangci/sandbox/go.mod"
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-build3379720613=/tmp/go-build -gno-record-gcc-switches"

Related to golangci/golangci-lint#2649 (comment)

[dominikh]

Fixed, thanks.