cmd/compile: typecheck panic, interface conversion: types.Object is nil, not *ir.Name

[zhuah]

What version of Go are you using (go version)?

$ go version
go version devel go1.18-6df0957060 Mon Jan 10 04:23:42 2022 +0000 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env

What did you do?

After updated to latest tip commit, my package failed to compile:
It seems due to this commit 931e84a

I have made a reproduce demo based on #50121 and 5b9207f

-- go.mod --
module test

-- pkg/pkg.go --
package pkg

type Builder[T any] struct{}

func (r Builder[T]) New() T {
	var v T
	return v
}

func (r Builder[T]) New2() T {
	return r.New()
}

func BuildInt() int {
	return Builder[int]{}.New()
}

-- main.go --
package main

import (
	"fmt"

	"test/pkg"
)

func BuildInt() int {
	return pkg.BuildInt()
}

func main() {
	fmt.Println(BuildInt())
}

the difference with #50121 is the func (r Builder[T]) New2() T method.
and the error logs is here:

# test
panic: interface conversion: types.Object is nil, not *ir.Name

goroutine 1 [running]:
cmd/compile/internal/typecheck.(*crawler).markInlBody.func1({0x1a8fee0, 0xc0000b4300?})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:257 +0x60e
cmd/compile/internal/ir.Visit.func1({0x1a8fee0, 0xc0000b4300})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:105 +0x30
cmd/compile/internal/ir.doNodes(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:1512
cmd/compile/internal/ir.(*CallExpr).doChildren(0xc0000a0a20, 0xc00011bec0)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:263 +0x132
cmd/compile/internal/ir.DoChildren(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0x1a8faf8, 0xc0000a0a20})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.doNodes(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:1512
cmd/compile/internal/ir.(*ReturnStmt).doChildren(0x1a91650?, 0xc00011bec0)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:1049 +0x8c
cmd/compile/internal/ir.DoChildren(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0x1a91650, 0xc000092f00})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.Visit({0x1a91650, 0xc000092f00}, 0xc00011bea8)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:108 +0xb8
cmd/compile/internal/ir.VisitList(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:114
cmd/compile/internal/typecheck.(*crawler).markInlBody(0xc00011be60, 0x1886720?)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:327 +0x2f4
cmd/compile/internal/typecheck.(*crawler).markInlBody.func1({0x1a910d8, 0xc000455790?})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:305 +0x225
cmd/compile/internal/ir.Visit.func1({0x1a910d8, 0xc000455790})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:105 +0x30
cmd/compile/internal/ir.(*CallExpr).doChildren(0xc000390ea0, 0xc00011be90)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:260 +0x56
cmd/compile/internal/ir.DoChildren(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0x1a8faf8, 0xc000390ea0})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.doNodes(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:1512
cmd/compile/internal/ir.(*ReturnStmt).doChildren(0x1a91650?, 0xc00011be90)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/node_gen.go:1049 +0x8c
cmd/compile/internal/ir.DoChildren(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:94
cmd/compile/internal/ir.Visit.func1({0x1a91650, 0xc0004764b0})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:106 +0x57
cmd/compile/internal/ir.Visit({0x1a91650, 0xc0004764b0}, 0xc00011be78)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:108 +0xb8
cmd/compile/internal/ir.VisitList(...)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/ir/visit.go:114
cmd/compile/internal/typecheck.(*crawler).markInlBody(0xc00011be60, 0x18c5f20?)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:327 +0x2f4
cmd/compile/internal/typecheck.(*crawler).markObject(0x10cd89e?, 0xc000455450)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:50 +0x2f
cmd/compile/internal/typecheck.crawlExports({0xc00008d7a0, 0x2, 0x10d1d2c?})
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/crawler.go:37 +0xbf
cmd/compile/internal/typecheck.WriteExports({0x1a89fa0, 0xc0005cb740}, 0x1)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/typecheck/iexport.go:305 +0x65
cmd/compile/internal/noder.WriteExports(0xc0005d4590)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/noder/export.go:40 +0x7a
cmd/compile/internal/gc.dumpCompilerObj(0xc0005d4590?)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/gc/obj.go:107 +0x28
cmd/compile/internal/gc.dumpobj1({0x7ffeefbff239, 0x50}, 0x3)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/gc/obj.go:63 +0x17b
cmd/compile/internal/gc.dumpobj()
	/usr/local/Cellar/gotip/src/cmd/compile/internal/gc/obj.go:44 +0x36
cmd/compile/internal/gc.Main(0x1948e30)
	/usr/local/Cellar/gotip/src/cmd/compile/internal/gc/main.go:330 +0x11bc
main.main()
	/usr/local/Cellar/gotip/src/cmd/compile/main.go:55 +0xdd

[ALTree]

Another issue with the same error: #48094.

cc @danscales @randall77

[gopherbot]

Change https://golang.org/cl/377714 mentions this issue: cmd/compile: resolve dictionaries/shape methods in markInlBody, if needed

[danscales]

@zhuah Thanks for the issue report and the simplified test case. It pointed out a problem with my recent change for generics and inlining, and also another nice test case in general.

[gopherbot]

Change https://go.dev/cl/390335 mentions this issue: cmd/compile: fix reentrancy issue in unified IR function body reading