cmd/compile: regression in taking pointer of array literal

[dsnet]

Commit dfeecda from https://golang.org/cl/42175 caused a regression that causes this code to now fail to compile:

package main
import "fmt"
func main() {
	fmt.Println(&[...]string{"abc", "def", "ghi"})
}

The compiler output is:

# command-line-arguments
./main.go:8:46: use of [...] array outside of array literal
./main.go:8:46: internal compiler error: invalid alignment for [...]string

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
	/usr/local/go.tip/src/runtime/debug/stack.go:24 +0xa7
cmd/compile/internal/gc.Fatalf(0xb7ec95, 0x18, 0xc4203344d0, 0x1, 0x1)
	/usr/local/go.tip/src/cmd/compile/internal/gc/subr.go:181 +0x230
cmd/compile/internal/gc.dowidth(0xc42032e780)
	/usr/local/go.tip/src/cmd/compile/internal/gc/align.go:372 +0x304
cmd/compile/internal/gc.checkwidth(0xc42032e780)
	/usr/local/go.tip/src/cmd/compile/internal/gc/align.go:424 +0x17c
cmd/compile/internal/gc.typecheck1(0xc4202f5400, 0x44, 0x0)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:501 +0x7e36
cmd/compile/internal/gc.typecheck(0xc4202f5400, 0x44, 0x0)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:201 +0x78a
cmd/compile/internal/gc.typecheckcomplit(0xc4202f5080, 0x0)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:2926 +0x13e
cmd/compile/internal/gc.typecheck1(0xc4202f5080, 0x12, 0xc420322f00)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:837 +0x579b
cmd/compile/internal/gc.typecheck(0xc4202f5080, 0x12, 0xc420322f00)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:201 +0x78a
cmd/compile/internal/gc.typecheck1(0xc4202f5000, 0x1, 0x4b3aba)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:1250 +0x4e32
cmd/compile/internal/gc.typecheck(0xc4202f5000, 0x1, 0x3)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:201 +0x78a
cmd/compile/internal/gc.typecheckslice(0xc42000c738, 0x1, 0x1, 0x1)
	/usr/local/go.tip/src/cmd/compile/internal/gc/typecheck.go:55 +0x46
cmd/compile/internal/gc.Main(0xb8f390)
	/usr/local/go.tip/src/cmd/compile/internal/gc/main.go:473 +0x1f22
main.main()
	/usr/local/go.tip/src/cmd/compile/main.go:49 +0x95

\cc @josharian

[josharian]

Thanks as always, @dsnet! Fix is on its way.

[gopherbot]

CL https://golang.org/cl/43290 mentions this issue.