cmd/compile: panic: runtime error: index out of range in ssagen

[matthewdupre]

Go version

1.26.2

Output of go env in your module/workspace:

Starting with UID: 9001
AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/user/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/user/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2830984150=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/dev/null'
GOMODCACHE='/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/user/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='local'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.26.2'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Compile a fairly large closed source project which I unfortunately cannot share with you. The issue is intermittent, and later reruns passed. Note that the compilation happens in parallel with other go builds.

What did you see happen?

panic: runtime error: index out of range [-536880912]

goroutine 60 [running]:
cmd/compile/internal/ssagen.genssa.func1(0x4ccb3780?, 0x10ee?)
	cmd/compile/internal/ssagen/ssa.go:7337 +0xeb
cmd/compile/internal/ssa.(*FuncDebug).PutLocationListDwarf5(0x104b0c0?, {0x10ee4d23bf40, 0x13, 0x3c}, 0x10ee4771a488, 0x10ee4ccb3780, 0x10ee4c357600)
	cmd/compile/internal/ssa/debug.go:1502 +0x246
cmd/compile/internal/ssa.(*FuncDebug).PutLocationList(0x58f4f5?, {0x10ee4d23bf40?, 0x10ee4ccb3700?, 0x5?}, 0x10ee4c60e580?, 0x1?, 0xffffffffffffffff?)
	cmd/compile/internal/ssa/debug.go:1478 +0x25
cmd/compile/internal/dwarfgen.createComplexVars.createComplexVar.func1({0x104b0c0?, 0x10ee4ccb3780?}, {0x104b0c0?, 0x10ee4c357600?})
	cmd/compile/internal/dwarfgen/dwarf.go:568 +0x5f
cmd/internal/dwarf.putvar(...)
	cmd/internal/dwarf/dwarf.go:1635
cmd/internal/dwarf.putscope({0x10d4ec8, 0x10ee4771a488}, 0x10ee4ce3dd50, {0x10ee4cfc5b80, 0x1, 0x1}, 0x0, 0x6, {0x10ee4d2667b0, 0x0, ...})
	cmd/internal/dwarf/dwarf.go:1509 +0xb4e
cmd/internal/dwarf.putPrunedScopes({0x10d4ec8, 0x10ee4771a488}, 0x10ee4ce3dd50, 0x6)
	cmd/internal/dwarf/dwarf.go:1191 +0x5ba
cmd/internal/dwarf.PutConcreteFunc({0x10d4ec8, 0x10ee4771a488}, 0x10ee4ce3dd50, 0x0, 0x10ee49d3da40?)
	cmd/internal/dwarf/dwarf.go:1388 +0x247
cmd/internal/obj.(*Link).populateDWARF(...)
	cmd/internal/obj/dwarf.go:384
cmd/internal/obj.Flushplist(0x10ee4771a488, 0x10ee4ce3df18, 0x10ee4d210420)
	cmd/internal/obj/plist.go:173 +0x13d9
cmd/compile/internal/objw.(*Progs).Flush(...)
	cmd/compile/internal/objw/prog.go:112
cmd/compile/internal/ssagen.Compile(0x10ee49d3da40, 0x0, 0x0?)
	cmd/compile/internal/ssagen/pgen.go:329 +0x6df
cmd/compile/internal/gc.compileFunctions.func5.1(0x10ee475b3680?)
	cmd/compile/internal/gc/compile.go:199 +0x38
cmd/compile/internal/gc.compileFunctions.func3.1()
	cmd/compile/internal/gc/compile.go:181 +0x30
created by cmd/compile/internal/gc.compileFunctions.func3 in goroutine 17
	cmd/compile/internal/gc/compile.go:180 +0x325

What did you expect to see?

The compiler not panic.

[mwriter]

@matthewdupre

Is the project going to be built normally using GOEXPERIMENT=nodwarf5?

[gabyhelp]

Related Issues

• cmd/compile: panic while running compiler: index out of range during lowered cse #17918 (closed)
• cmd/compile: panic during generic deadcode #56777 (closed)
• cmd/internal/sys: runtime error: index out of range [] with length 0 #55054 (closed)
• cmd/compile/internal/SSA: panic in Compile on linux-amd64-noopt #54906 (closed)
• cmd/compile: crash in regalloc #15585 (closed)
• cmd/compile: internal compiler error: panic during lower #29215 (closed)
• cmd/compile: panic during sccp while compiling main runtime error: index out of range [-5] #64826 (closed)
• cmd/link: "panic: index out of range" on go tip linker #22941 (closed)
• panic: runtime error: index out of range。 cmd/link/internal/ld.decodetypeKind(...) #51935 (closed)
• cmd/compile: panic while compiling empty package in a loop #16726 (closed)

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[matthewdupre]

@mwriter Yes, nodwarf5 is used to make Windows CGO builds work.

[mwriter]

Yes, nodwarf5 is used to make Windows CGO builds work

Then it's definitely another problem with DWARF5.
But without at least an approximate test environment for reproduction, it will probably be very difficult for the team to solve this.