gccgo: compilation failure for example with non-ASCII package

[thanm]

Please answer these questions before submitting your issue. Thanks!

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

gccgo tip
go version go1.10.3 gccgo (GCC) 9.0.0 20180920 (experimental) linux/amd64

Does this issue reproduce with the latest release?

Yes

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

linux/amd64

What did you do?

Unpack tar file tarfile.gz
in your $GOPATH, change dir to Äbar, then build.

What did you expect to see?

Clean build

What did you see instead?

$ tar xzvf - < tarfile.gz
./Äbar/
./Äbar/Äbar.go
./Äfoo/
./Äfoo/Äfoo.go
$ cd ./Äbar/
$ go build -compiler gccgo .
$ go build -compiler gccgo  .
# Äbar
./Äbar.go:5:7: error: imported and not used: Äfoo
5 |  "Äfoo"
  |       ^
./Äbar.go:9:45: error: reference to undefined name ‘Äfoo’
9 |  fmt.Printf("Äfoo.Äbar(33) returns %v\n", Äfoo.Äbar(33))
  |                                             ^
$

This program builds cleanly with the regular Go compiler.

I need to spend more time in the debugger, but I think this is a parsing issue, since it is happening very early in the compilation. The call to Äfoo.Äbar is somehow not getting tracked as a reference to the Äfoo package, hence the incorrect error. More investigation needed.

[gopherbot]

Change https://golang.org/cl/137736 mentions this issue: compiler: fix parsing issue with non-ASCII first package char

[gopherbot]

Change https://golang.org/cl/138075 mentions this issue: test: add testcase for gccgo compile failure