cmd/compile: runtime error: makeslice: len out of range

[josharian]

package p

type S struct {
	i interface {
		f([10736000000000]int)
	}
}

compiling this results in:

$ go tool compile x.go
panic: runtime error: makeslice: len out of range

goroutine 1 [running]:
cmd/compile/internal/gc.bvalloc(...)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/bv.go:21
cmd/compile/internal/gc.livenessemit(0xc4200b8480, 0xc420300328, 0xc420300390)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/plive.go:1254 +0x7c
cmd/compile/internal/gc.liveness(0xc4202f84e0, 0xc420322140, 0x0)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/plive.go:1302 +0x131
cmd/compile/internal/gc.genssa(0xc420322140, 0xc420086690)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/ssa.go:4379 +0x1352
cmd/compile/internal/gc.compileSSA(0xc42038a000, 0x0)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/pgen.go:242 +0x7e
cmd/compile/internal/gc.compile(0xc42038a000)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/pgen.go:219 +0x218
cmd/compile/internal/gc.funccompile(0xc42038a000)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/dcl.go:1049 +0xb7
cmd/compile/internal/gc.genwrapper(0xc4203178c0, 0xc4202f5200, 0xc4203207e0, 0x0)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/subr.go:1786 +0x73e
cmd/compile/internal/gc.imethods(0xc4203178c0, 0xc420324a10, 0x10102dc, 0xc42031c498)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/reflect.go:424 +0x318
cmd/compile/internal/gc.dtypesym(0xc4203178c0, 0xc4202efb60)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/reflect.go:1189 +0x13d5
cmd/compile/internal/gc.dtypesym(0xc420317800, 0xc4202efd00)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/reflect.go:1277 +0xe14
cmd/compile/internal/gc.dumpsignats()
	/Users/josh/go/tip/src/cmd/compile/internal/gc/reflect.go:1441 +0x3e7
cmd/compile/internal/gc.dumpobj1(0xc42001239c, 0x3, 0x3)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/obj.go:141 +0x2af
cmd/compile/internal/gc.dumpobj()
	/Users/josh/go/tip/src/cmd/compile/internal/gc/obj.go:51 +0x61
cmd/compile/internal/gc.Main(0x17756e8)
	/Users/josh/go/tip/src/cmd/compile/internal/gc/main.go:631 +0x24f7
main.main()
	/Users/josh/go/tip/src/cmd/compile/main.go:49 +0x89

Similar to #20529, although this also reproduces with 1.8. For code with a similar structure, see #20778.

Marking as unplanned, pending real code encountering this problem.

Found with go-fuzz.

[josharian]

This no longer panics on tip:

$ go tool compile x.go
<autogenerated>:1: stack frame too large (>1GB): 81909179 MB locals + 81909179 MB args