cmd/compile: internal compiler error: assertion failed [1.18 backport]

[dmgk]

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

$ go version
go version go1.18.4 freebsd/amd64

Does this issue reproduce with the latest release?

This seems to be a regression in go1.18.4.
Both go1.18.3 and the current tip (go version devel go1.19-c006b7ac27 Wed Jul 13 18:35:00 2022 +0000 freebsd/amd64) do not have this issue.

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/dg/.cache/go-build"
GOENV="/home/dg/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="freebsd"
GOINSECURE=""
GOMODCACHE="/home/dg/.gopath/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="freebsd"
GOPATH="/home/dg/.gopath"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/dg/opt/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/dg/opt/go/pkg/tool/freebsd_amd64"
GOVCS=""
GOVERSION="go1.18.4"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/home/dg/tmp/gopass/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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1954080416=/tmp/go-build -gno-record-gcc-switches"

What did you do?

$ git clone https://github.com/gopasspw/gopass.git
$ cd gopass
$ go build -gcflags=-d=panic ./...

What did you expect to see?

A successful build.

What did you see instead?

# github.com/gopasspw/gopass/internal/backend
internal/backend/registry.go:85:45: internal compiler error: assertion failed

goroutine 1 [running]:
runtime/debug.Stack()
	/home/dg/opt/go/src/runtime/debug/stack.go:24 +0x65
cmd/compile/internal/base.FatalfAt({0x839d70?, 0xc0?}, {0xd297e9, 0x10}, {0x0, 0x0, 0x0})
	/home/dg/opt/go/src/cmd/compile/internal/base/print.go:227 +0x1d7
cmd/compile/internal/base.Fatalf(...)
	/home/dg/opt/go/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/base.Assert(...)
	/home/dg/opt/go/src/cmd/compile/internal/base/print.go:239
cmd/compile/internal/noder.assert(...)
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:27
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe9ac10, 0xc00087b9e0})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1307 +0x1e7
cmd/compile/internal/ir.(*SelectorExpr).editChildren(0xc0008519e0, 0xc000885940)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:1106 +0x62
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe9a440, 0xc0008519e0})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/ir.(*CallExpr).editChildren(0xc00085d440, 0xc000885940)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:274 +0x64
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe98758, 0xc00085d440})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/ir.(*BinaryExpr).editChildren(0xc000851980, 0xc000885940)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:204 +0x62
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe98500, 0xc000851980})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/ir.editNodes(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:1521
cmd/compile/internal/ir.(*ReturnStmt).editChildren(0xc0008688c0?, 0xc000885940)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:1056 +0xa2
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe9a2b0, 0xc000868a00})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe989b0, 0xc000868820})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1230 +0x95b
cmd/compile/internal/ir.editNodes(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:1521
cmd/compile/internal/ir.(*CallExpr).editChildren(0xc00085d3b0, 0xc000885940)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:276 +0x1c2
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe98758, 0xc00085d3b0})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/ir.editNodes(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/node_gen.go:1521
cmd/compile/internal/ir.(*Func).editChildren(0xc0007794e0?, 0xc000885940?)
	/home/dg/opt/go/src/cmd/compile/internal/ir/func.go:157 +0x74
cmd/compile/internal/ir.EditChildren(...)
	/home/dg/opt/go/src/cmd/compile/internal/ir/visit.go:185
cmd/compile/internal/noder.(*genInst).dictPass.func1({0xe990b8, 0xc000842c60})
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1219 +0x74
cmd/compile/internal/noder.(*genInst).dictPass(0x1399780, 0xc000839bf0)
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:1365 +0x126
cmd/compile/internal/noder.(*genInst).buildInstantiations(0x1399780)
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:78 +0x1d2
cmd/compile/internal/noder.BuildInstantiations(...)
	/home/dg/opt/go/src/cmd/compile/internal/noder/stencil.go:44
cmd/compile/internal/noder.(*irgen).generate(0xc00037a480, {0xc0003fef00, 0x6, 0x203000?})
	/home/dg/opt/go/src/cmd/compile/internal/noder/irgen.go:331 +0x3d1
cmd/compile/internal/noder.check2({0xc0003fef00, 0x6, 0x6})
	/home/dg/opt/go/src/cmd/compile/internal/noder/irgen.go:92 +0x16d
cmd/compile/internal/noder.LoadPackage({0xc0000c6120, 0x6, 0x0?})
	/home/dg/opt/go/src/cmd/compile/internal/noder/noder.go:90 +0x335
cmd/compile/internal/gc.Main(0xd51b20)
	/home/dg/opt/go/src/cmd/compile/internal/gc/main.go:191 +0xb13
main.main()
	/home/dg/opt/go/src/cmd/compile/main.go:55 +0xdd

See also #53762

cc @golang/compiler

[dmgk]

460a93b seems to be the culprit, reverting it fixes the build.

[cuonglm]

It's weird that checkout 7eeec1f on master branch works.

[cuonglm]

So I think the problem is that with the master, we use method expression closures to implement bound method calls, which is implemented in 2 CLs:

• https://go-review.googlesource.com/c/go/+/385254
• https://go-review.googlesource.com/c/go/+/385274

So the bound method calls in:

func (r *Registry[K, V]) Prioritized() []V {
	bes := maps.Values(r.backends)
	sort.Slice(bes, func(i, j int) bool {
		return bes[i].Priority() < bes[j].Priority()
	})

	return bes
}

is not cast anymore.

I'm not sure what should we do in this case, cherry pick those 2 CLs? cc @randall77 @mdempsky

[mdempsky]

I think let's revert the backport CL. Go 1.19 will be out soon, and I think it's more important in the mean time that we don't destabilize the Go 1.18 release branch.

[gopherbot]

Change https://go.dev/cl/417615 mentions this issue: Revert "[release-branch.go1.18] cmd/compile: fix missing dict pass for type assertions"

[dmitshur]

@mknyszek @mdempsky This issue is currently in Backlog milestone, which probably needs updating. Do you think it's better to move this issue to Go1.19 milestone and close it (since it's fixed at tip) and ask gopherbot to file a backport issue for 1.18 which will create an issue in the right milestone—or would it work better to just manually edit this issue to be a Go 1.18 backport issue?