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cmd/compile: internal compiler error: next missing from LHS of .autotmp_23, _ := ([]byte)(.autotmp_4), 0 #73823

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cmd/compile: internal compiler error: next missing from LHS of .autotmp_23, _ := ([]byte)(.autotmp_4), 0#73823
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cuonglm
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compiler/runtimeIssues related to the Go compiler and/or runtime.release-blocker
Milestone
 
Go1.25
@Rajalakshmi-Girish

Description

@Rajalakshmi-Girish
Rajalakshmi-Girish
opened on May 22, 2025 · edited by Rajalakshmi-Girish

Go version

go version go1.25-devel_a8e0641d5b

Output of go env in your module/workspace:

[root@raji-x86-workspace1 kubernetes]# go env
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='0'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/root/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/root/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build4279966289=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/root/kubernetes/go.mod'
GOMODCACHE=''
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH=''
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/root/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.25-devel_53b9eae387 Wed May 21 21:20:52 2025 -0700'
GOWORK='/root/kubernetes/go.work'
PKG_CONFIG='pkg-config'
[root@raji-x86-workspace1 kubernetes]#

What did you do?

git clone https://github.com/kubernetes/kubernetes
export CGO_ENABLED=0
export FORCE_HOST_GO=y
KUBE_BUILD_PLATFORMS=linux/x86_64 make cross

What did you see happen?

[root@raji-x86-workspace1 kubernetes]# KUBE_BUILD_PLATFORMS=linux/x86_64 make cross
+++ [0521 23:22:26] Building go targets for linux/amd64
    k8s.io/apiextensions-apiserver (static)
    k8s.io/component-base/logs/kube-log-runner (static)
    k8s.io/kube-aggregator (static)
    k8s.io/kubernetes/cluster/gce/gci/mounter (static)
    k8s.io/kubernetes/cmd/kubeadm (static)
    k8s.io/kubernetes/cmd/kube-apiserver (static)
    k8s.io/kubernetes/cmd/kube-controller-manager (static)
    k8s.io/kubernetes/cmd/kubelet (non-static)
    k8s.io/kubernetes/cmd/kube-proxy (static)
    k8s.io/kubernetes/cmd/kube-scheduler (static)
+++ [0521 23:23:10] Building go targets for linux/amd64
    k8s.io/component-base/logs/kube-log-runner (static)
    k8s.io/kubernetes/cmd/kubeadm (static)
    k8s.io/kubernetes/cmd/kubelet (non-static)
    k8s.io/kubernetes/cmd/kube-proxy (static)
+++ [0521 23:23:37] Building go targets for linux/amd64
    k8s.io/kubernetes/cmd/kubectl (static)
    k8s.io/kubernetes/cmd/kubectl-convert (static)
+++ [0521 23:24:12] Building go targets for linux/amd64
    github.com/onsi/ginkgo/v2/ginkgo (non-static)
    k8s.io/kubernetes/test/conformance/image/go-runner (non-static)
    k8s.io/kubernetes/test/e2e/e2e.test (test)
+++ [0521 23:25:34] Building go targets for linux/amd64
    github.com/onsi/ginkgo/v2/ginkgo (non-static)
    k8s.io/kubernetes/cmd/kubemark (static)
    k8s.io/kubernetes/test/e2e_node/e2e_node.test (test)
# go.etcd.io/etcd/server/v3/storage/backend
sync/atomic/type.go:47:6: internal compiler error: next missing from LHS of .autotmp_23, _ := ([]byte)(.autotmp_4), 0

Please file a bug report including a short program that triggers the error.
https://go.dev/issue/new
!!! [0521 23:26:00] Call tree:
!!! [0521 23:26:00]  1: /root/kubernetes/hack/lib/golang.sh:997 kube::golang::build_binaries_for_platform(...)
!!! [0521 23:26:00]  2: hack/make-rules/build.sh:28 kube::golang::build_binaries(...)
!!! [0521 23:26:00] Call tree:
!!! [0521 23:26:00]  1: hack/make-rules/build.sh:28 kube::golang::build_binaries(...)
make[1]: *** [Makefile:97: all] Error 1
make: *** [Makefile:496: cross] Error 1
[root@raji-x86-workspace1 kubernetes]#

What did you expect to see?

Build of Kubernetes successful.

Activity

gopherbot
added
compiler/runtimeIssues related to the Go compiler and/or runtime.
on May 22, 2025
mkumatag

mkumatag commented on May 22, 2025

@mkumatag
mkumatag
on May 22, 2025

simple repro steps:

$ git clone https://github.com/kubernetes/kubernetes.git
$ cd kubernetes
$ go test -c k8s.io/kubernetes/test/e2e_node
# go.etcd.io/etcd/server/v3/storage/backend
/usr/local/go/src/sync/atomic/type.go:47:6: internal compiler error: next missing from LHS of .autotmp_23, _ := ([]byte)(.autotmp_4), 0

Please file a bug report including a short program that triggers the error.
https://go.dev/issue/new
mateusz834

mateusz834 commented on May 22, 2025

@mateusz834
mateusz834
on May 22, 2025
Member

This assertion is hit in ReassignOracle:

go/src/cmd/compile/internal/ir/reassignment.go

Line 181 in 53b9eae

base.Fatalf("%v missing from LHS of %v", n, defn) 

# go.etcd.io/etcd/server/v3/storage/backend
goroutine 1 [running]:
cmd/compile/internal/ir.(*ReassignOracle).staticValue1(0xc0020789c0, {0x10639d0, 0xc00185c3c0})
        /home/mateusz/code/go/src/cmd/compile/internal/ir/reassignment.go:184 +0x27e
cmd/compile/internal/ir.(*ReassignOracle).StaticValue(0xc0020789c0, {0x10639d0?, 0xc00185c3c0?})
        /home/mateusz/code/go/src/cmd/compile/internal/ir/reassignment.go:144 +0xb2
cmd/compile/internal/escape.(*batch).rewriteWithLiterals(0xc002097d48, {0x1064268, 0xc0017e3d80}, 0xc001859680)
        /home/mateusz/code/go/src/cmd/compile/internal/escape/escape.go:573 +0x1cb
cmd/compile/internal/escape.Batch({0xc00207ea00, 0x4, 0x10}, 0x0?)
        /home/mateusz/code/go/src/cmd/compile/internal/escape/escape.go:162 +0x2d7
cmd/compile/internal/ir.(*bottomUpVisitor).visit(...)
        /home/mateusz/code/go/src/cmd/compile/internal/ir/scc.go:121
cmd/compile/internal/ir.VisitFuncsBottomUp({0xc001bbcc08, 0x198, 0x2?}, 0xf13678)
        /home/mateusz/code/go/src/cmd/compile/internal/ir/scc.go:58 +0x3c2
cmd/compile/internal/escape.Funcs(...)
        /home/mateusz/code/go/src/cmd/compile/internal/escape/escape.go:125
cmd/compile/internal/gc.Main(0xf134b8)
        /home/mateusz/code/go/src/cmd/compile/internal/gc/main.go:269 +0x1f0d
main.main()
        /home/mateusz/code/go/src/cmd/compile/main.go:57 +0xf9

It looks like CL 649079/CL 673795

CC @golang/compiler @thepudds

mateusz834
added
release-blocker
on May 22, 2025
mateusz834
added this to the Go1.25 milestone on May 22, 2025
Rajalakshmi-Girish

Rajalakshmi-Girish commented on May 22, 2025

@Rajalakshmi-Girish
Rajalakshmi-Girish
on May 22, 2025
Author

It started occurring after https://go-review.googlesource.com/c/go/+/673795

mateusz834

mateusz834 commented on May 22, 2025

@mateusz834
mateusz834
on May 22, 2025
Member

After a quick debugging session:

I believe this is unrelated to these change - in a sense that these changes exposed a bug elsewhere.
For me it looks like it is related to loopvar logic in the compiler (loopvar.ForCapture).

diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index 253ec3257a..f6bf13a03b 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -240,22 +240,53 @@ func Main(archInit func(*ssagen.ArchInfo)) {
        interleaved.DevirtualizeAndInlinePackage(typecheck.Target, profile)

        noder.MakeWrappers(typecheck.Target) // must happen after inlining

        // Get variable capture right in for loops.
        var transformed []loopvar.VarAndLoop
        for _, fn := range typecheck.Target.Funcs {
                transformed = append(transformed, loopvar.ForCapture(fn)...)
        }
        ir.CurFunc = nil

+       for _, f := range typecheck.Target.Funcs {
+               ir.Visit(f, func(nn ir.Node) {
+                       if nn.Op() != ir.ONAME {
+                               return
+                       }
+                       n := nn.(*ir.Name).Canonical()
+                       if n.Class != ir.PAUTO {
+                               return
+                       }
+
+                       defn := n.Defn
+                       if defn == nil {
+                               return
+                       }
+
+               FindRHS:
+                       switch defn.Op() {
+                       case ir.OAS2:
+                               defn := defn.(*ir.AssignListStmt)
+                               for _, lhs := range defn.Lhs {
+                                       if lhs == n {
+                                               break FindRHS
+                                       }
+                               }
+                               base.FatalfAt(n.Pos(), "%v HERE missing from LHS of %v\n%v", n, defn)
+                       default:
+                               return
+                       }
+               })
+       }
+
        // Build init task, if needed.
        pkginit.MakeTask()

If you apply this change before the ForCapture calls, then the FatalfAt call is not reached, when i move if after the ForCapture calls (exactly as the diff above) it fails.

thepudds

thepudds commented on May 22, 2025

@thepudds
thepudds
on May 22, 2025
Member

Hi @mateusz834, thanks for taking a quick look! (I'm just coming online; I'll start digging in shortly).

gopherbot

gopherbot commented on May 22, 2025

@gopherbot
gopherbot
on May 22, 2025
Contributor

Change https://go.dev/cl/675475 mentions this issue: cmd/compile: fix ICE when transforming loopvar

cuonglm

cuonglm commented on May 22, 2025

@cuonglm
cuonglm
on May 22, 2025
Member

Hi @mateusz834, thanks for taking a quick look! (I'm just coming online; I'll start digging in shortly).

I think the problem is that loopvar transforming the for variable without updating its Defn properly, causing incorrect asignment statement check of ReassignOracle.

thepudds

thepudds commented on May 22, 2025

@thepudds
thepudds
on May 22, 2025
Member

This set of repro steps seem to work now with https://go.dev/cl/675475 from @cuonglm:

$ go install golang.org/dl/gotip@latest
$ gotip download 675475
$ git clone --depth=1 https://github.com/kubernetes/kubernetes.git
$ cd kubernetes/ 
$ gotip test -c k8s.io/kubernetes/test/e2e_node
thepudds

thepudds commented on May 22, 2025

@thepudds
thepudds
on May 22, 2025
Member

From the kubernetes directory, this also seems to work now:

$ gotip build ./... && gotip test -c ./...
cuonglm

cuonglm commented on May 22, 2025

@cuonglm
cuonglm
on May 22, 2025
Member

This set of repro steps seem to work now with https://go.dev/cl/675475 from @cuonglm:

$ go install golang.org/dl/gotip@latest
$ gotip download 675475
$ git clone --depth=1 https://github.com/kubernetes/kubernetes.git
$ cd kubernetes/ 
$ gotip test -c k8s.io/kubernetes/test/e2e_node

Yeah, I am still working on a standalone reproducer.

cuonglm

cuonglm commented on May 22, 2025

@cuonglm
cuonglm
on May 22, 2025
Member

Standalone reproducer:


package p

type Backend interface {
	Hash(ignores func(bucketName, keyName []byte) bool) (uint32, error)
}

type backend struct {
}

func first() (key []byte, value []byte) {
	return
}

func (b *backend) View(fn func() error) error {
	return nil
}

func (b *backend) Hash(ignores func(bucketName, keyName []byte) bool) (uint32, error) {
	err := b.View(func() error {
		for next, _ := first(); next != nil; next, _ = first() {
			_ = next
		}
		return nil
	})
	return 0, err
}

func defragdb() error {
	for next, _ := first(); next != nil; next, _ = first() {
		_ = f(next)
		ForEach(func(k, v []byte) error {
			_ = next
			return nil
		})
	}

	return nil
}

func ForEach(fn func(k, v []byte) error) error {
	for k, v := first(); k != nil; k, v = first() {
		if err := fn(k, v); err != nil {
			return err
		}
	}
	return nil
}

//go:noinline
func f(any) string {
	return ""
}
gopherbot

gopherbot commented on May 22, 2025

@gopherbot
gopherbot
on May 22, 2025
Contributor

Change https://go.dev/cl/675495 mentions this issue: cmd/compile: use better fatal message for staticValue1

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        cmd/compile: internal compiler error: next missing from LHS of .autotmp_23, _ := ([]byte)(.autotmp_4), 0 · Issue #73823 · golang/go