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cmd/compile: nil pointer dereference #57715

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richsoap opened this issue Jan 10, 2023 · 1 comment
Closed

cmd/compile: nil pointer dereference #57715

richsoap opened this issue Jan 10, 2023 · 1 comment
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compiler/runtime Issues related to the Go compiler and/or runtime. FrozenDueToAge generics Issue is related to generics NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one.

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

$ go version
go version go1.19.4 linux/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output
$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/***/.cache/go-build"
GOENV="/home/***/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/***/go/pkg/mod"
GONOPROXY="***"
GONOSUMDB="***"
GOOS="linux"
GOPATH="/home/***/go"
GOPRIVATE="***"
GOPROXY="***"
GOROOT="/usr/local/lib/go"
GOSUMDB="sum.golang.google.cn"
GOTMPDIR=""
GOTOOLDIR="/usr/local/lib/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.19.4"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/***/workspace/golang/***/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 -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build868479349=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I've written a simple reproduce code. Why not read the code?

The following code will cause 'internal compiler error'.
playground link

package main

import "fmt"

type GreenHand interface {
	SayHi()
}

type GreenHands[G GreenHand] []G

func (gs GreenHands[G]) SayHi() {
	for _, g := range gs {
		g.SayHi()
	}
}

type IntGreenHand[A any] struct {
	ExampleGreenHand[A, int64]
}

type ExampleGreenHand[A, B any] struct{}

func (e ExampleGreenHand[A, B]) SayHi() {
	fmt.Println("Hello!")
}

func main() {
	make(GreenHands[IntGreenHand[string]], 1).SayHi()
}

After add this method, everything looks good.
playground link

func (g IntGreenHand[A]) SayHi() {
	g.ExampleGreenHand.SayHi()
}

What did you expect to see?

I expected to see "Hello!" in my terminal without adding method.

What did you see instead?

I saw this message when I compiled 'panic code'.

./prog.go:23:4: internal compiler error: panic: runtime error: invalid memory address or nil pointer dereference

Please file a bug report including a short program that triggers the error.
https://go.dev/issue/new

Go build failed.
@richsoap richsoap changed the title affected/package: go compiler panic during processing generic slice affected/package: go compiler paniced during processing generic slice Jan 10, 2023
@richsoap richsoap changed the title affected/package: go compiler paniced during processing generic slice panic/compiler: go compiler paniced during processing generic slice Jan 10, 2023
@seankhliao seankhliao changed the title panic/compiler: go compiler paniced during processing generic slice cmd/compile: mil pointer dereference Jan 10, 2023
@gopherbot gopherbot added the compiler/runtime Issues related to the Go compiler and/or runtime. label Jan 10, 2023
@cagedmantis cagedmantis changed the title cmd/compile: mil pointer dereference cmd/compile: nil pointer dereference Jan 10, 2023
@cagedmantis cagedmantis added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Jan 10, 2023
@randall77
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This works correctly on tip.
We're not currently backporting fixes to the pre-unified generics implementation, so I'm going to close this.
Thanks for the report though.

@randall77 randall77 added the generics Issue is related to generics label Jan 10, 2023
@golang golang locked and limited conversation to collaborators Jan 10, 2024
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Labels
compiler/runtime Issues related to the Go compiler and/or runtime. FrozenDueToAge generics Issue is related to generics NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one.
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@cagedmantis @randall77 @gopherbot @richsoap