x/tools/gopls: illegal line number panic

[myitcv]

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

$ go version
go version devel +b7689f5aa3 Fri Jan 31 06:02:00 2020 +0000 linux/amd64
$ go list -m golang.org/x/tools
golang.org/x/tools v0.0.0-20200213224642-88e652f7a869
$ go list -m golang.org/x/tools/gopls
golang.org/x/tools/gopls v0.1.8-0.20200213224642-88e652f7a869

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
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/myitcv/.cache/go-build"
GOENV="/home/myitcv/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/myitcv/gostuff"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/myitcv/gos"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/myitcv/.vim/plugged/govim/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-build830932815=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Removing the closing } of a function at the end of a file results in a panic:

panic: illegal line number

goroutine 950 [running]:
go/token.(*File).LineStart(0xc000345800, 0x7, 0x0)
	/home/myitcv/gos/src/go/token/position.go:222 +0xe8
golang.org/x/tools/internal/lsp/cache.fixMissingCurlies(0xc000174700, 0xc0001ba4b0, 0xdbfec0, 0xc000397f90, 0xc000345800, 0xc000a8fc80, 0x5f, 0x5f, 0x5, 0xc000174800, ...)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:336 +0x149
golang.org/x/tools/internal/lsp/cache.fixSrc.func1(0xdbf580, 0xc0001ba4b0, 0xdbfec0, 0xc000397f90, 0xba3301)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:302 +0x17d
golang.org/x/tools/internal/lsp/cache.walkASTWithParent.func1(0xdbf580, 0xc0001ba4b0, 0xdc0200)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:288 +0xb2
go/ast.inspector.Visit(0xc00033cf20, 0xdbf580, 0xc0001ba4b0, 0x0, 0x0)
	/home/myitcv/gos/src/go/ast/walk.go:373 +0x3a
go/ast.Walk(0xdbc4c0, 0xc00033cf20, 0xdbf580, 0xc0001ba4b0)
	/home/myitcv/gos/src/go/ast/walk.go:52 +0x66
go/ast.Walk(0xdbc4c0, 0xc00033cf20, 0xdbfec0, 0xc000397f90)
	/home/myitcv/gos/src/go/ast/walk.go:285 +0x2946
go/ast.walkStmtList(0xdbc4c0, 0xc00033cf20, 0xc000c33680, 0x3, 0x4)
	/home/myitcv/gos/src/go/ast/walk.go:32 +0x9e
go/ast.Walk(0xdbc4c0, 0xc00033cf20, 0xdbf580, 0xc0001ba840)
	/home/myitcv/gos/src/go/ast/walk.go:224 +0x1adf
go/ast.Walk(0xdbc4c0, 0xc00033cf20, 0xdbfa80, 0xc0001baa80)
	/home/myitcv/gos/src/go/ast/walk.go:344 +0xd98
go/ast.walkDeclList(0xdbc4c0, 0xc00033cf20, 0xc00069f6f0, 0x1, 0x1)
	/home/myitcv/gos/src/go/ast/walk.go:38 +0x9e
go/ast.Walk(0xdbc4c0, 0xc00033cf20, 0xdbfa00, 0xc000174700)
	/home/myitcv/gos/src/go/ast/walk.go:353 +0x264e
go/ast.Inspect(...)
	/home/myitcv/gos/src/go/ast/walk.go:385
golang.org/x/tools/internal/lsp/cache.walkASTWithParent(0xdbfa00, 0xc000174700, 0xc000c33800)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:271 +0x9e
golang.org/x/tools/internal/lsp/cache.fixSrc(0xc000174700, 0xc000345800, 0xc000a8fc80, 0x5f, 0x5f, 0xc000a8fc80, 0x5f, 0x5f)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:295 +0xc0
golang.org/x/tools/internal/lsp/cache.parseGo(0xdcbea0, 0xc0003c1ef0, 0xc0003bef40, 0xdca560, 0xc0003454a0, 0x2, 0x0)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:140 +0x827
golang.org/x/tools/internal/lsp/cache.(*cache).ParseGoHandle.func1(0xdcbde0, 0xc000c334c0, 0x0, 0x468486)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/lsp/cache/parse.go:57 +0x59
golang.org/x/tools/internal/memoize.(*Handle).run.func1(0xdcbde0, 0xc000c334c0, 0xc0003c1c50, 0xc000345680)
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/memoize/memoize.go:216 +0x6b
created by golang.org/x/tools/internal/memoize.(*Handle).run
	/home/myitcv/gostuff/pkg/mod/golang.org/x/tools@v0.0.0-20200213224642-88e652f7a869/internal/memoize/memoize.go:210 +0x116

Log file: fail.log

What did you expect to see?

No panic

What did you see instead?

As above.

---

cc @stamblerre

FYI @leitzler

[gopherbot]

Change https://golang.org/cl/219498 mentions this issue: internal/lsp/cache: fix crash fixing curlies near EOF