cmd/compile: internal compiler error: cannot inline function containing closure

[ALTree]

go version devel +5e954047bc Fri Mar 24 20:07:15 2017 +0000 linux/amd64

The following program:

package p

func f1() {
	f2()
}

func f2() {
	if false {
		_ = func() {}
	}
}

crashes the compiler on tip, but not in go1.8 and older.

./0.go:4:4: internal compiler error: cannot inline function containing closure: 
.   CLOSURE l(9) ff(1) tc(1) p.f2.func1 FUNC-func()

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
	/home/alberto/go/src/runtime/debug/stack.go:24 +0x79
cmd/compile/internal/gc.Fatalf(0xad5716, 0x2e, 0xc4203048a0, 0x1, 0x1)
	/home/alberto/go/src/cmd/compile/internal/gc/subr.go:175 +0x230
cmd/compile/internal/gc.(*inlsubst).node(0xc420305380, 0xc4200b23c0, 0xc42000f500)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:1031 +0xd2f
cmd/compile/internal/gc.(*inlsubst).node(0xc420305380, 0xc4202dfe60, 0x1)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:1035 +0x626
cmd/compile/internal/gc.(*inlsubst).list(0xc420305380, 0xc4202d5d60, 0x0, 0x0, 0xe76a08)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:952 +0xd1
cmd/compile/internal/gc.(*inlsubst).node(0xc420305380, 0xc4202dfc20, 0x1)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:1039 +0x841
cmd/compile/internal/gc.(*inlsubst).list(0xc420305380, 0xc420306040, 0xc4202f6800, 0xc42030a360, 0xc4202da6c0)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:952 +0xd1
cmd/compile/internal/gc.mkinlcall1(0xc42030a240, 0xc4202f6400, 0x0, 0xa37bc0)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:829 +0xb6d
cmd/compile/internal/gc.mkinlcall(0xc42030a240, 0xc4202f6400, 0xc420305600, 0xe77e80)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:547 +0x78
cmd/compile/internal/gc.inlnode(0xc42030a240, 0x1)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:509 +0x460
cmd/compile/internal/gc.inlnodelist(0xc420306120)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:380 +0x55
cmd/compile/internal/gc.inlnode(0xc4200b2140, 0x2)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:486 +0x2e1
cmd/compile/internal/gc.inlcalls(0xc4200b2140)
	/home/alberto/go/src/cmd/compile/internal/gc/inl.go:336 +0x50
cmd/compile/internal/gc.Main.func1(0xc420306020, 0x1, 0x4, 0xc4202fc800)
	/home/alberto/go/src/cmd/compile/internal/gc/main.go:465 +0x7f
cmd/compile/internal/gc.(*bottomUpVisitor).visit(0xc420305ab0, 0xc4200b2140, 0x0)
	/home/alberto/go/src/cmd/compile/internal/gc/esc.go:106 +0x259
cmd/compile/internal/gc.visitBottomUp(0xc4202d5fe0, 0x3, 0x4, 0xadb438)
	/home/alberto/go/src/cmd/compile/internal/gc/esc.go:62 +0xe7
cmd/compile/internal/gc.Main(0xadb350)
	/home/alberto/go/src/cmd/compile/internal/gc/main.go:456 +0x26cd
main.main()
	/home/alberto/go/src/cmd/compile/main.go:49 +0x95

This may be related to #19679.

[josharian]

This is pretty easy to fix directly, but probably should be fixed by fixing #19699 instead.

[ALTree]

Ok, leaving to you to decide if you want to merge this with #19699.

[josharian]

Unlike #19699, this has a concrete problem and a reproducer, and it admits of a narrower fix, so I want to leave it open.

[gopherbot]

CL https://golang.org/cl/38773 mentions this issue.