cmd/compile: internal compiler error: maplit: entry is not a literal: "ADAT":composite literal

[ncw]

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

$ go version
go version devel +ba978f5fff Tue Apr 30 23:31:26 2019 +0000 linux/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/ncw/.cache/go-build"
GOENV="/home/ncw/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/ncw/go"
GOPROXY="direct"
GOROOT="/opt/go/go-tip"
GOSUMDB="off"
GOTMPDIR=""
GOTOOLDIR="/opt/go/go-tip/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/ncw/go/src/github.com/ncw/rclone/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-build788254528=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I compiled rclone with go tip (in the CI).

When compiling vendor/github.com/goftp/server the compiler emits a fatal error

What did you expect to see?

No error

What did you see instead?

This internal error

# github.com/goftp/server
/home/ncw/go/pkg/mod/github.com/goftp/server@v0.0.0-20190304020633-eabccc535b5a/cmd.go:24:23: internal compiler error: maplit: entry is not a literal: "ADAT":composite literal

goroutine 1 [running]:
runtime/debug.Stack(0xfc9580, 0xc00000e018, 0x0)
	/opt/go/go-tip/src/runtime/debug/stack.go:24 +0x9d
cmd/compile/internal/gc.Fatalf(0xe3af24, 0x22, 0xc0006a0610, 0x1, 0x1)
	/opt/go/go-tip/src/cmd/compile/internal/gc/subr.go:188 +0x291
cmd/compile/internal/gc.maplit(0xc0003a1480, 0xc0009e3860, 0xc0006a1468)
	/opt/go/go-tip/src/cmd/compile/internal/gc/sinit.go:965 +0x251
cmd/compile/internal/gc.anylit(0xc0003a1480, 0xc0009e3860, 0xc0006a1468)
	/opt/go/go-tip/src/cmd/compile/internal/gc/sinit.go:1149 +0x7f
cmd/compile/internal/gc.walkexpr(0xc0003a1480, 0xc0006a1468, 0xc00044b300)
	/opt/go/go-tip/src/cmd/compile/internal/gc/walk.go:1462 +0x4206
cmd/compile/internal/gc.walkexpr(0xc000474b00, 0xc0006a1468, 0x0)
	/opt/go/go-tip/src/cmd/compile/internal/gc/walk.go:642 +0x18f9
cmd/compile/internal/gc.walkstmt(0xc000474b00, 0xc0009dd880)
	/opt/go/go-tip/src/cmd/compile/internal/gc/walk.go:159 +0xd94
cmd/compile/internal/gc.walkstmtlist(0xc0002d9800, 0x58, 0x80)
	/opt/go/go-tip/src/cmd/compile/internal/gc/walk.go:79 +0x46
cmd/compile/internal/gc.walk(0xc0009cb080)
	/opt/go/go-tip/src/cmd/compile/internal/gc/walk.go:63 +0x3da
cmd/compile/internal/gc.compile(0xc0009cb080)
	/opt/go/go-tip/src/cmd/compile/internal/gc/pgen.go:235 +0x6b
cmd/compile/internal/gc.funccompile(0xc0009cb080)
	/opt/go/go-tip/src/cmd/compile/internal/gc/pgen.go:221 +0xc1
cmd/compile/internal/gc.fninit(0xc000453000, 0x120, 0x200)
	/opt/go/go-tip/src/cmd/compile/internal/gc/init.go:65 +0x610
cmd/compile/internal/gc.Main(0xe4a5a0)
	/opt/go/go-tip/src/cmd/compile/internal/gc/main.go:682 +0x38fa
main.main()
	/opt/go/go-tip/src/cmd/compile/main.go:51 +0xac

Bisection result

85387aa from #26552

85387aa364f5ebb8c1c10ee2de78ae8ded5a80dd is the first bad commit
commit 85387aa364f5ebb8c1c10ee2de78ae8ded5a80dd
Author: Keith Randall <khr@google.com>
Date:   Tue Apr 30 09:47:19 2019 -0700

    cmd/compile: remove dynamic entry handling from sinit/maplit
    
    The order pass now handles all the dynamic entries.
    
    Update #26552
    
    Followup to CL 174417
    
    Change-Id: Ie924cadb0e0ba36c423868f654f13040100b44c6
    Reviewed-on: https://go-review.googlesource.com/c/go/+/174498
    Run-TryBot: Keith Randall <khr@golang.org>
    TryBot-Result: Gobot Gobot <gobot@golang.org>
    Reviewed-by: Matthew Dempsky <mdempsky@google.com>

:040000 040000 9df008720e90b1b4c661fefa3acd28b9bc74083c 82e701bdc3a14a8292e156bd2d15bda61cb0b0b6 M	src
bisect run success

@randall77

To reproduce

git clone https://github.com/ncw/rclone.git
rclone/vendor/github.com/goftp/server
go install

Sorry I haven't had the time to make a minimal testcase.

[gopherbot]

Change https://golang.org/cl/174777 mentions this issue: cmd/compile: fix maplit init panics for dynamic entry