x/tools/gopls: Hover: on `var x Alias`, where `type Alias = Named`, incorrectly shows underlying type of Named

[rothelius]

gopls version

Build info

golang.org/x/tools/gopls v0.18.1
golang.org/x/tools/gopls@v0.18.1 h1:2xJBNzdImS5u/kV/ZzqDLSvlBSeZX+pWY9uKVP7Pask=
github.com/BurntSushi/toml@v1.4.1-0.20240526193622-a339e1f7089c h1:pxW6RcqyfI9/kWtOwnv/G+AzdKuy2ZrqINhenH4HyNs=
github.com/google/go-cmp@v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
golang.org/x/exp/typeparams@v0.0.0-20241210194714-1829a127f884 h1:1xaZTydL5Gsg78QharTwKfA9FY9CZ1VQj6D/AZEvHR0=
golang.org/x/mod@v0.23.0 h1:Zb7khfcRGKk+kqfxFaP5tZqCnDZMjC5VtUBs87Hr6QM=
golang.org/x/sync@v0.11.0 h1:GGz8+XQP4FvTTrjZPzNKTMFtSXH80RAzG+5ghFPgK9w=
golang.org/x/telemetry@v0.0.0-20241220003058-cc96b6e0d3d9 h1:L2k9GUV2TpQKVRGMjN94qfUMgUwOFimSQ6gipyJIjKw=
golang.org/x/text@v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
golang.org/x/tools@v0.30.1-0.20250221230316-5055f70f240c h1:Ja/5gV5a9Vvho3p2NC/T2TtxhHjrWS/2DvCKMvA0a+Y=
golang.org/x/vuln@v1.1.3 h1:NPGnvPOTgnjBc9HTaUx+nj+EaUYxl5SJOWqaDYGaFYw=
honnef.co/go/tools@v0.5.1 h1:4bH5o3b5ZULQ4UrBmP+63W9r7qIkqJClEA9ko5YKx+I=
mvdan.cc/gofumpt@v0.7.0 h1:bg91ttqXmi9y2xawvkuMXyvAA/1ZGJqYAEGjXuP0JXU=
mvdan.cc/xurls/v2@v2.5.0 h1:lyBNOm8Wo71UknhUs4QTFUNNMyxy2JEIaKKo0RWOh+8=
go: go1.24.2

go env

AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE='on'
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/fabianr/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/fabianr/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/81/cvjd0t010fgbf1nc2p9xcq4w0000gn/T/go-build3394958907=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/fabianr/svn/be/trunk/gamelogic/gohome/src/elk/go.mod'
GOMODCACHE='/Users/fabianr/svn/be/trunk/gamelogic/gohome/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/fabianr/svn/be/trunk/gamelogic/gohome'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/fabianr/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Ran gopls definition on the variable names of the snippet

type (
	Named  int
	Alias  = Named
	Alias2 = Alias
)

var (
	named  Named
	alias  Alias
	alias2 Alias2
)

What did you see happen?

I got the definitions var named Named, type Named int and var alias2 Alias2, respectively.

What did you expect to see?

I would expect the definition of the alias variable to be of, well, a variable; probably var alias Alias. Interestingly enough the second-degree alias isn't affected.

Editor and settings

No response

Logs

No response

[gabyhelp]

Related Issues

• x/tools/gopls: type alias rename changes aliased type #61625 (closed)
• x/tools/gopls: References: report unkeyed composite literals as implicit references to struct fields #74307
• x/tools/gopls: undeclared name when accessing symbols from other files #35337 (closed)
• x/tools/gopls: named return values with shared type cause incorrect highlighting #60589 (closed)
• x/tools/gopls: completion: missing field completion in multi-LHS assignment "a.C, b.‸" #70065 (closed)
• x/tools/gopls: missing semantic tokens for function parameters in block #56257 (closed)
• x/tools/gopls: No warning "loop variable xx captured by func literal". #60016 (closed)
• x/tools/gopls: #52425 (closed)
• x/tools/gopls: IDE shows undeclared name on every symbols when accessing from other files #34951 (closed)
• cmd/compile, x/tools/go/packages: gotypesalias=1 does not seem to get used correctly for deps on Go 1.23 #70394 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[adonovan]

This behavior was implemented by https://go.dev/cl/644495. I think there are three problems here:

1. hovering over (a def or use of) alias now reports a type, not a var. This is categorically a regression.
2. hovering over alias shows its RHS type (int) whereas hovering over alias2 shows its surface type (Alias2). This inconsistency is a bug. It could be fixed two ways (always or never unalias, and if unaliasing, do so recursively).
3. was x/tools/gopls: show underlying type on hover over alias #71286 (unalias) a mistake? I am inclined to think so. If you hover over a reference to alias far from its declaration, it's useful to know its alias type name. You can also execute a definition query then hover again if you want to strip the alias this type off.

So I vote for reverting CL 644495 and restoring the old behavior. Thoughts?