Go: cmd/compile: ICE when compiling github.com/llgcode/draw2d/draw2dimg

[reusee]

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

go version devel +c00c1efbd8 Sun Apr 8 05:22:26 2018 +0000 linux/amd64

Does this issue reproduce with the latest release?

yes

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/home/reus/.go-cache"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/reus/go"
GORACE=""
GOROOT="/home/reus/gotip"
GOTMPDIR=""
GOTOOLDIR="/home/reus/gotip/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build524165607=/tmp/go-build -gno-record-gcc-switches"

What did you do?

download github.com/llgcode/draw2d/draw2dimg and build

What did you expect to see?

build ok

What did you see instead?

build failed

# github.com/llgcode/draw2d/draw2dimg
<autogenerated>:1: internal compiler error: 4 uncompiled functions

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
    /home/reus/gotip/src/runtime/debug/stack.go:24 +0xa7
cmd/compile/internal/gc.Fatalf(0xbca91c, 0x17, 0xc000b37a50, 0x1, 0x1)
    /home/reus/gotip/src/cmd/compile/internal/gc/subr.go:182 +0x1f7
cmd/compile/internal/gc.Main(0xbdd9c8)
    /home/reus/gotip/src/cmd/compile/internal/gc/main.go:683 +0x2ad7
main.main()
    /home/reus/gotip/src/cmd/compile/main.go:49 +0x96

[davecheney]

Thank you for raising this issue. Could you do a little bisecting and see if you can figure out when this was introduced?

On 8 Apr 2018, at 17:27, reusee [e-mail] wrote:

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

go version devel +c00c1efbd8 Sun Apr 8 05:22:26 2018 +0000 linux/amd64

Does this issue reproduce with the latest release?

yes

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/home/reus/.go-cache"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/reus/go"
GORACE=""
GOROOT="/home/reus/gotip"
GOTMPDIR=""
GOTOOLDIR="/home/reus/gotip/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build524165607=/tmp/go-build -gno-record-gcc-switches"

What did you do?

download github.com/llgcode/draw2d/draw2dimg and build

What did you expect to see?

build ok

What did you see instead?

build failed

github.com/llgcode/draw2d/draw2dimg

:1: internal compiler error: 4 uncompiled functions

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
/home/reus/gotip/src/runtime/debug/stack.go:24 +0xa7
cmd/compile/internal/gc.Fatalf(0xbca91c, 0x17, 0xc000b37a50, 0x1, 0x1)
/home/reus/gotip/src/cmd/compile/internal/gc/subr.go:182 +0x1f7
cmd/compile/internal/gc.Main(0xbdd9c8)
/home/reus/gotip/src/cmd/compile/internal/gc/main.go:683 +0x2ad7
main.main()
/home/reus/gotip/src/cmd/compile/main.go:49 +0x96

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[reusee]

introduced by

fa3e9d27f333d1cdb75889c2bff8e71d62f82e11 is the first bad commit
commit fa3e9d27f333d1cdb75889c2bff8e71d62f82e11
Author: Josh Bleecher Snyder <[email protected]>
Date:   Sun Apr 23 05:06:22 2017 -0700

    cmd/compile: compile all functions concurrently

[davecheney]

Thank you. /cc @josharian

[mvdan]

I managed to reduce this to two packages and less than 20 lines of Go:

$ go list .
mvdan.cc/p1
$ cat f1.go
package p1

import "mvdan.cc/p1/p2"

type T1 struct {
        *p2.T2
}
$ cat p2/f2.go
package p2

type T2 struct{}

func (t *T2) M2(a, b float64) {
        variadic(a, b)
}

func variadic(points ...float64) {
        println(points)
}
$ go build
# mvdan.cc/p1
<autogenerated>:1: internal compiler error: 2 uncompiled functions

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
        /home/mvdan/tip/src/runtime/debug/stack.go:24 +0xa7
cmd/compile/internal/gc.Fatalf(0xbca87c, 0x17, 0xc000365a50, 0x1, 0x1)
        /home/mvdan/tip/src/cmd/compile/internal/gc/subr.go:182 +0x1f7
cmd/compile/internal/gc.Main(0xbdd928)
        /home/mvdan/tip/src/cmd/compile/internal/gc/main.go:683 +0x2ad7
main.main()
        /home/mvdan/tip/src/cmd/compile/main.go:49 +0x96

It seems like all of these are required to reproduce the crash:

• Two packages. Potentially related to import/export data.
• Struct embedding.
• Variadic arguments.
• float64. If it's changed to int for example, it no longer crashes.

I've gotten a bit stuck trying to reduce it further. But at least it no longer involves dozens of image drawing packages.

[josharian]

Nice find! Thanks, @mvdan, for the minimized test case, it was very helpful.

[gopherbot]

Change https://golang.org/cl/105615 mentions this issue: cmd/compile: loop to ensure all autogenerated functions are compiled