cmd/compile: internal compiler crash when enabling libfuzzer instrumentation

[randall77]

Go version

tip

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/khr/Library/Caches/go-build'
GOENV='/Users/khr/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/khr/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/khr/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/khr/sandbox/ro5'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/khr/sandbox/ro5/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='devel go1.24-943abbfd74 Wed Sep 25 08:36:07 2024 -0700'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/khr/Library/Application Support/go/telemetry'
GCCGO='gccgo'
GOARM64='v8.0'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/khr/sandbox/ro5/src/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/z9/dty110711l9cr9w3ktv1_2380000gn/T/go-build1149802709=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

package main

type T struct {
	A
}

type A struct {
}

//go:noinline
func (a *A) Foo(s [2]string) {
}

Build with

go tool compile -d=libfuzzer=1 test.go

What did you see happen?

This crashes the tip compiler with an error like

<autogenerated>:1: internal compiler error: '(*T).Foo': func (*T).Foo, startMem[b1] has different values, old v1, new v22

What did you expect to see?

no crash

[gabyhelp]

Related Issues and Documentation

• cmd/compile: fuzzing triggers various crashes or internal compiler errors on tip #49019
• cmd/compile: ICE compiling rangefunc for < 1.23 in combination with Cgo #67497 (closed)
• cmd/compile: internal compiler error: 'F': func F, startMem[b1] has different values #61992 (closed)
• internal/fuzz: array literal initialization causes ICE "unhandled stmt ASOP" while fuzzing #56105 (closed)
• cmd/link: using -fuzz with test that links with cgo on darwin causes linker failure #65169 (closed)
• cmd/go: "undefined: testing.InternalFuzzTarget" when attempting to build minimal test package (on tip) #51666 (closed)
• go build: internal compiler error #58607 (closed)
• cmd/compile: internal compiler error: '(*TimeSeries).extract': func (*TimeSeries).extract, startMem[b1] has different values, old v1, new v31 #69791
• cmd/compile: internal compiler error: Type.Elem UNSAFEPTR #31174
• cmd/compile: internal compiler error: bad live variable at entry (part 2) #29218 (closed)

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[gopherbot]

Change https://go.dev/cl/619075 mentions this issue: cmd/compile: use call block instead of entry block for tail call expansion