cmd/compile: range over rune literal causes internal compiler error

[dominikh]

Go version

go version devel go1.22-b4fa5b163d Thu Nov 30 13:03:03 2023 +0000 linux/amd64

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

ODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/dominikh/.cache/go-build'
GOENV='/home/dominikh/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/dominikh/prj/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/dominikh/prj'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/home/dominikh/prj/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/dominikh/prj/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='devel go1.22-b4fa5b163d Thu Nov 30 13:03:03 2023 +0000'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/dominikh/prj/src/example.com/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 -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2316299034=/tmp/go-build -gno-record-gcc-switches'

What did you do?

$ cat foo.go
package main

func main() {
	for i := range 'a' {
		println(i)
	}
}

$ go build foo.go

What did you expect to see?

No ICE

What did you see instead?

# command-line-arguments
<unknown line number>: internal compiler error: assertion failed

goroutine 1 [running]:
runtime/debug.Stack()
	../../go/src/runtime/debug/stack.go:24 +0x5e
cmd/compile/internal/base.FatalfAt({0xf5f728?, 0x0?}, {0xdff80b, 0x10}, {0x0, 0x0, 0x0})
	../../go/src/cmd/compile/internal/base/print.go:225 +0x1d7
cmd/compile/internal/base.Fatalf(...)
	../../go/src/cmd/compile/internal/base/print.go:194
cmd/compile/internal/base.Assert(...)
	../../go/src/cmd/compile/internal/base/print.go:237
cmd/compile/internal/noder.assert(...)
	../../go/src/cmd/compile/internal/noder/stencil.go:15
cmd/compile/internal/noder.(*writer).expr(0xc00047bc30, {0xf63c08?, 0xc000482370?})
	../../go/src/cmd/compile/internal/noder/writer.go:1735 +0x278b
cmd/compile/internal/noder.(*writer).forStmt(0xc00047bc30, 0xc0004822d0)
	../../go/src/cmd/compile/internal/noder/writer.go:1430 +0x1b9
cmd/compile/internal/noder.(*writer).stmt1(0xc00047bc30, {0xf61870?, 0xc0004822d0})
	../../go/src/cmd/compile/internal/noder/writer.go:1289 +0x24f
cmd/compile/internal/noder.(*writer).stmts(0xc00047bc30, {0xc00004a600, 0x1, 0x0?})
	../../go/src/cmd/compile/internal/noder/writer.go:1220 +0x8e
cmd/compile/internal/noder.(*pkgWriter).bodyIdx(0xc000002180, 0xc000481b80, 0xc000481ac0, 0xc0000f60a0)
	../../go/src/cmd/compile/internal/noder/writer.go:1124 +0x186
cmd/compile/internal/noder.(*writer).funcExt(0xc00047b8c0, 0xc0004861c0)
	../../go/src/cmd/compile/internal/noder/writer.go:1059 +0x328
cmd/compile/internal/noder.(*writer).doObj(0xc00047b810, 0xc00047b8c0, {0xf679e0, 0xc0004861c0})
	../../go/src/cmd/compile/internal/noder/writer.go:819 +0x213
cmd/compile/internal/noder.(*pkgWriter).objIdx(0xc000002180, {0xf679e0, 0xc0004861c0})
	../../go/src/cmd/compile/internal/noder/writer.go:778 +0x579
cmd/compile/internal/noder.(*pkgWriter).objInstIdx(0xc000002180, {0xf679e0, 0xc0004861c0}, 0x0, 0x0)
	../../go/src/cmd/compile/internal/noder/writer.go:719 +0xf0
cmd/compile/internal/noder.(*writer).obj(...)
	../../go/src/cmd/compile/internal/noder/writer.go:695
cmd/compile/internal/noder.writePkgStub({0x0?, {0x0?, 0x0?}}, {0xc0000b03e0, 0x1, 0x1})
	../../go/src/cmd/compile/internal/noder/unified.go:317 +0x645
cmd/compile/internal/noder.unified(...)
	../../go/src/cmd/compile/internal/noder/unified.go:172
cmd/compile/internal/noder.LoadPackage({0xc0001420f0, 0x1, 0x1})
	../../go/src/cmd/compile/internal/noder/noder.go:77 +0x4d2
cmd/compile/internal/gc.Main(0xe2f510)
	../../go/src/cmd/compile/internal/gc/main.go:197 +0xbbd
main.main()
	../../go/src/cmd/compile/main.go:57 +0xf9

[gopherbot]

Change https://go.dev/cl/546296 mentions this issue: cmd/compile: fix typecheck range over rune literal