cmd/compile: internal compiler error: dictionary variable not captured by value

[ALTree]

$ gotip version
go version devel go1.19-3474cd4eee Sat May 14 04:25:13 2022 +0000 linux/amd64

package main

func f[T int](t T) {
	for true {
		func() {
			t = func() T { return t }()
		}()
	}
}

func main() {
	f(0)
}

$ gotip build crash.go
# command-line-arguments
./crash.go:7:4: internal compiler error: dictionary variable not captured by value

goroutine 1 [running]:
runtime/debug.Stack()
	./gotip/src/runtime/debug/stack.go:24 +0x65
cmd/compile/internal/base.FatalfAt({0x412fc0?, 0xc0?}, {0xd540b1, 0x29}, {0x0, 0x0, 0x0})
	./gotip/src/cmd/compile/internal/base/print.go:227 +0x1d7
cmd/compile/internal/escape.(*batch).flowClosure(0xc000172fc0?, {0xc0004132d0?, 0x1?, 0x0?, 0x48?}, 0x0?)
	./gotip/src/cmd/compile/internal/escape/escape.go:251 +0x2d6
cmd/compile/internal/escape.Batch({0xc0004008c8?, 0x2, 0x3}, 0x0?)
	./gotip/src/cmd/compile/internal/escape/escape.go:153 +0x3ce
cmd/compile/internal/ir.(*bottomUpVisitor).visit(0xc00041e2a0, 0xc00040a3c0)
	./gotip/src/cmd/compile/internal/ir/scc.go:127 +0x303
cmd/compile/internal/ir.(*bottomUpVisitor).visit.func1({0xea91f8?, 0xc00040a3c0?})
	./gotip/src/cmd/compile/internal/ir/scc.go:81 +0x45
cmd/compile/internal/ir.(*bottomUpVisitor).visit.func2({0xea9c08, 0xc0003fb970})
	./gotip/src/cmd/compile/internal/ir/scc.go:91 +0x7e
cmd/compile/internal/ir.Visit.func1({0xea9c08, 0xc0003fb970})
	./gotip/src/cmd/compile/internal/ir/visit.go:105 +0x30
cmd/compile/internal/ir.(*CallExpr).doChildren(0xc000170360, 0xc0004201e0)
	./gotip/src/cmd/compile/internal/ir/node_gen.go:237 +0x56
cmd/compile/internal/ir.DoChildren(...)
	./gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0xea8a10, 0xc000170360})
	./gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.doNodes(...)
	./gotip/src/cmd/compile/internal/ir/node_gen.go:1373
cmd/compile/internal/ir.(*Func).doChildren(0xea91f8?, 0xc0004201e0?)
	./gotip/src/cmd/compile/internal/ir/func.go:151 +0x6e
cmd/compile/internal/ir.DoChildren(...)
	./gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0xea91f8, 0xc00040a000})
	./gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.Visit({0xea91f8, 0xc00040a000}, 0xc00005f370)
	./gotip/src/cmd/compile/internal/ir/visit.go:108 +0xb8
cmd/compile/internal/ir.(*bottomUpVisitor).visit(0xc00041e2a0, 0xc00040a000)
	./gotip/src/cmd/compile/internal/ir/scc.go:87 +0x1d5
cmd/compile/internal/ir.VisitFuncsBottomUp({0xc000130400, 0x5, 0x2?}, 0xd668f0)
	./gotip/src/cmd/compile/internal/ir/scc.go:60 +0x108
cmd/compile/internal/escape.Funcs(...)
	./gotip/src/cmd/compile/internal/escape/escape.go:119
cmd/compile/internal/gc.Main(0xd667d0)
	./gotip/src/cmd/compile/internal/gc/main.go:268 +0xdf7
main.main()
	./gotip/src/cmd/compile/main.go:57 +0xdd

cc @mdempsky @cuonglm

[gopherbot]

Change https://go.dev/cl/406176 mentions this issue: cmd/compile: fix inlining function has shape in type

[ALTree]

package main

func f[T int](g T) {
	for true {
		_ = func() T { return func(int) T { return g }(0) }()
	}
}

func main() {
	f(0)
}

This slightly different reproducer triggers a compiler crash for me after the CL above.

[gopherbot]

Change https://go.dev/cl/406475 mentions this issue: cmd/compile: tighten the condition for inlining shape/non-shape function

[cuonglm]

@ALTree Thanks for the new test case, should be fixed by CL 406475.

[gopherbot]

Change https://go.dev/cl/424775 mentions this issue: cmd/compile: enable more inlining for unified IR