gccgo: type omission in slice literal (inside a map/array literal) should be accepted

[cherrymui]

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

go version go1.10.3 gccgo (GCC) 9.0.0 20180709 (experimental) linux/amd64

What did you do?

package p

type S []T
type T struct { x int }

var _ = map[string]*S{
	"a": {
		{ 1 },
	},
}

var _ = [1]*S{ { {1}, } }

What did you expect to see?

$ go tool compile x5.go
$

No error.

What did you see instead?

$ gccgo -c x5.go
x5.go:8:3: error: may only omit types within composite literals of slice, array, or map type
   { 1 },
   ^
x5.go:12:18: error: may only omit types within composite literals of slice, array, or map type
 var _ = [1]*S{ { {1}, } }
                  ^

Note that a standalone slice literal S{ {1}, } is accepted. Also if it is map[string]S instead of map[string]*S, or [1]S instead of [1]*S, it is also accepted.

cc @ianlancetaylor

[gopherbot]

Change https://golang.org/cl/123477 mentions this issue: test: add test of valid code that gccgo failed to compile

[gopherbot]

Change https://golang.org/cl/123479 mentions this issue: compiler: fix parsing of composite literals with omitted pointer types