cmd/gc: internal compiler error when inlining due to missing export data

[gopherbot]

by [email protected]:

If possible, include a link to a program on play.golang.org.

1. go get code.google.com/p/go-imap/go1/imap; I tested with 1f4117c0b3da tip
2. go build http://play.golang.org/p/HzNEcD0_NJ


What is the expected output?

A compiled program. Perhaps error messages telling me what I did wrong.

What do you see instead?

stephen@hotel:~/sandbox/go/src/imaptest$ go build imapidle.go
# command-line-arguments
walk [7f5ba5365c90]
.   CALL l(15) tc(1)
.   .   NONAME-imap.plainAuth u(1) a(1) l(15) x(0+0) tc(1) imap.plainAuth G0
.   CALL-list
.   .   ADDSTR l(15) tc(1) string
.   .   .   ADDSTR l(15) tc(1) string
.   .   .   .   ADDSTR l(15) tc(1) string
.   .   .   .   .   ADDSTR l(15) tc(1) string
.   .   .   .   .   .   NAME-imap.identity·4 u(1) a(1) l(15) x(0+0) class(PAUTO) ld(1)
tc(1) used(1) string
.   .   .   .   .   .   LITERAL-"\x00" l(15) tc(1) string
.   .   .   .   .   NAME-imap.username·2 u(1) a(1) l(15) x(0+0) class(PAUTO) ld(1)
tc(1) used(1) string
.   .   .   .   LITERAL-"\x00" l(15) tc(1) string
.   .   .   NAME-imap.password·3 u(1) a(1) l(15) x(0+0) class(PAUTO) ld(1) tc(1)
used(1) string
./imapidle.go:4: undefined: imap.plainAuth
./imapidle.go:15: tempname called with nil type
./imapidle.go:15: internal compiler error: walkexpr: switch 1 unknown op CALL l(15) tc(1)


Which compiler are you using (5g, 6g, 8g, gccgo)?

6g

Which operating system are you using?

Debian Wheezy

Which version are you using?  (run 'go version')

go version go1.1 linux/amd64
devel +56909cb770fe Fri Jun 21 18:07:57 2013 -0700 (reported by mortdeus in #go-nuts)

[ality]

Comment 1:

Here's a small reproducer:
# a.go
package a
type I interface { F() }
type foo []byte
func (f foo) F() { return }
func Test(s string) I { return foo(s) }
# main.go
package main
import "./a"
func main() {
    i := a.Test("frumious")
    _ = i
}
Which gives the same error:
rundir               bugs/tmp.go         : exit status 1
walk [7f5e0a643018]
.   CALL l(6) tc(1)
.   .   NONAME-a.foo u(1) a(1) l(6) x(0+0) tc(1) a.foo G0
.   CALL-list
.   .   NAME-a.s·2 u(1) a(1) l(6) x(0+0) class(PAUTO) ld(1) tc(1) used(1) string
/home/apm/src/go/test/bugs/tmp.dir/main.go:3: undefined: a.foo
/home/apm/src/go/test/bugs/tmp.dir/main.go:6: tempname called with nil type
/home/apm/src/go/test/bugs/tmp.dir/main.go:6: internal compiler error: walkexpr: switch
1 unknown op CALL l(6) tc(1)
exit status 1
Note that if you change the underlying type of a.foo to string instead of []byte
it works fine.

Labels changed: added go1.2, removed priority-triage.

Status changed to Accepted.

[ality]

Comment 2:

A temporary workaround is to disable inlining (by building with -gcflags -l).

[remyoudompheng]

Comment 3:

Sorry for that, I'll do a patch.

Status changed to Started.

[remyoudompheng]

Comment 4:

Disabling inlining can be quite annoying performance-wise: another possible workaround
is to add a public variable "var Dummy foo" to force foo to be exported.

[ianlancetaylor]

Comment 5:

Labels changed: added go1.1.2, removed go1.2.

[remyoudompheng]

Comment 6:

This issue was closed by revision c1fc8d5.

Status changed to Fixed.

[adg]

Comment 7:

This issue was closed by revision 7f7bdef7fc85.