cmd/compile: failed to build istio with internal compiler error: width not calculated: func()

[johejo]

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

$ go version
go version devel +2b50ab2aee Tue Mar 2 06:38:07 2021 +0000 linux/amd64

Does this issue reproduce with the latest release?

No, gotip only.

1.16 is fine.

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/heijo/.cache/go-build"
GOENV="/home/heijo/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/heijo/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/heijo/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/heijo/ghq/go.googlesource.com/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/heijo/ghq/go.googlesource.com/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="devel +2b50ab2aee Tue Mar 2 06:38:07 2021 +0000"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/heijo/ghq/github.com/istio/istio/go.mod"
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-build3113425185=/tmp/go-build -gno-record-gcc-switches"

What did you do?

git clone https://github.com/istio/istio.git
cd istio/
go build ./...

What did you expect to see?

Build successful

What did you see instead?

# istio.io/istio/pilot/pkg/bootstrap
<autogenerated>:1: internal compiler error: width not calculated: func()

goroutine 5 [running]:
runtime/debug.Stack(0xf954c0, 0xc0000c4008, 0x0)
        /home/heijo/ghq/go.googlesource.com/go/src/runtime/debug/stack.go:24 +0x9f
cmd/compile/internal/base.FatalfAt(0x100000000001, 0xe5ea7d, 0x18, 0xc0041fb158, 0x1, 0x1)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/base/print.go:227 +0x1bc
cmd/compile/internal/base.Fatalf(...)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/types.CalcSize(0xc005027800)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/types/size.go:344 +0xf3
cmd/compile/internal/ssagen.TypeOK(0xc005027800, 0xc005027800)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:5243 +0x2f
cmd/compile/internal/ssagen.(*state).stmt(0xc0041d0000, 0xfa7850, 0xc0055c1d60)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1530 +0x26c
cmd/compile/internal/ssagen.(*state).stmtList(0xc0041d0000, 0xc00558bef0, 0x1, 0x1)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1312 +0x68
cmd/compile/internal/ssagen.(*state).stmt(0xc0041d0000, 0xfa7aa8, 0xc0055bcdc0)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1335 +0x1689
cmd/compile/internal/ssagen.(*state).stmtList(0xc0041d0000, 0xc0055c4480, 0x5, 0x8)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1312 +0x68
cmd/compile/internal/ssagen.(*state).stmt(0xc0041d0000, 0xfa7850, 0xc00500d720)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1330 +0xf3
cmd/compile/internal/ssagen.(*state).stmtList(0xc0041d0000, 0xc00512f000, 0xeb, 0x100)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:1312 +0x68
cmd/compile/internal/ssagen.buildssa(0xc0004ca580, 0x2, 0x0)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/ssa.go:565 +0x1645
cmd/compile/internal/ssagen.Compile(0xc0004ca580, 0x2)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/ssagen/pgen.go:158 +0x5f
cmd/compile/internal/gc.compileFunctions.func2.1(0xc004aa7b80, 0xc0004ca580, 0xc00580a7b0, 0xc00574b394)
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/gc/compile.go:127 +0x65
created by cmd/compile/internal/gc.compileFunctions.func2
        /home/heijo/ghq/go.googlesource.com/go/src/cmd/compile/internal/gc/compile.go:125 +0x8e

[networkimprov]

cc @mdempsky @cherrymui @thanm

(@seankhliao bug reports and feature requests usually get cc'd to owners during triage)

[mdempsky]

Does the issue reproduce with go build -gcflags=all=-d=inlfuncswithclosures=0?

[mark-rushakoff]

@mdempsky I made a minimal reproducer at https://github.com/mark-rushakoff/goissue44732. Yes, it still fails with those flags at go version devel +2b50ab2aee Tue Mar 2 06:38:07 2021 +0000 darwin/amd64.

[mdempsky]

Thanks! I'll take a look.

[mdempsky]

It looks like this fixes the issue:

diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index 9355174da8..c81e1bfc83 100644
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -508,6 +508,7 @@ func (p *iimporter) typAt(off uint64) *types.Type {
                        base.Fatalf("predeclared type missing from cache: %d", off)
                }
                t = p.newReader(off-predeclReserved, nil).typ1()
+               types.CheckSize(t)
                p.typCache[off] = t
        }
        return t

I'll need to dig into it more tonight to see if there's a better fix. I'm curious what changed that makes this necessary now.

If someone's able to bisect to find what commit caused the regression, that would be appreciated! (You'll probably have to bisect into the dev.regabi branch.)

[cuonglm]

Unless I'm mistaken, git bisect points to cc90e7a

[mdempsky]

@cuonglm Thanks! I can believe that bisection, though I'm puzzled at how it would actually cause this regression.

If someone wants to turn my diff from above into a proper CL with tests and make sure it doesn't break anything else, I think we can submit that as a quick fix.

[gopherbot]

Change https://golang.org/cl/299689 mentions this issue: cmd/compile: fix width not calculated for imported type

[cuonglm]

@mdempsky The puzzle was solved :)