x/pkgsite: exported methods of generic type omitted

[muhlemmer]

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

$ go version
go version go1.18beta1 linux/amd64

$ gotip version
go version devel go1.18-c8861432b8 Sun Jan 2 14:27:43 2022 +0000 linux/amd64

Does this issue reproduce with the latest release?

Beta1 release of Go 1.18 and master through gotip with type parameter support.

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/vscode/.cache/go-build"
GOENV="/home/vscode/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.18beta1"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/workspaces/godoc_generics_issue/go.mod"
GOWORK=""
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-build1808945237=/tmp/go-build -gno-record-gcc-switches"

gotip env Output

$ gotip env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/vscode/.cache/go-build"
GOENV="/home/vscode/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/vscode/sdk/gotip"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/vscode/sdk/gotip/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="devel go1.18-c8861432b8 Sun Jan 2 14:27:43 2022 +0000"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/workspaces/godoc_generics_issue/go.mod"
GOWORK=""
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-build338508180=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Add a generic (struct) type with methods:

type MyType[T any] struct {
	i T
}

func (m *MyType[T]) Set(i T) {
	m.i = i
}

func (m *MyType[T]) Get() T {
	return m.i
}

Run go doc or gotip doc (same output).

What did you expect to see?

MyType, and its Get() and Set() methods printed.

What did you see instead?

Methods added to a generic (struct) type are not printed.

package godoc_generics_issue // import "github.com/muhlemmer/godoc_generics_issue"

type MyType[T any] struct{ ... }

Additional info:

1. Running go doc -all does print the the methods, although they should also be printed without -all flag, as the methods are exported.
2. Runing pkgsite, the package page (http://127.0.0.1:8080/github.com/muhlemmer/godoc_generics_issue) also omits the methods.
3. Running godoc server, panics when visiting the the package page. I raised a seperate issue x/tools/godoc: panic with generic type with methods #50413, as I'm not sure if this is related or a different bug.

[ianlancetaylor]

CC @findleyr

[findleyr]

Thanks for the report.

CC @jba. https://golang.org/cl/375095 may be indirectly related.

Commented on the godoc issue, which I think is unrelated.

[jba]

I can't reproduce this. go doc <pkgname> shows only the type, not the methods, but that has always been its behavior. go doc <pkgname>.<type> shows the methods.

I found the same behavior at tip (e39ab9b) with the declarations given above.

[muhlemmer]

I can't reproduce this. go doc <pkgname> shows only the type, not the methods, but that has always been its behavior. go doc <pkgname>.<type> shows the methods.

I found the same behavior at tip (e39ab9b) with the declarations given above.

Ok, well my apologies then.

In fact, I found the godoc bug (panic) first and tried to find a common denominator. For instance, I found pkgsite omits the methods from from the page. A previous issue I reported on generics, there was a common bug. So I falsely assumed this to be a common bug with go doc as well.

I'll rephrase this issue to apply only to pkgsite:

Steps to reproduce:

1. Same source as the original issue;
2. Run pkgsite build against Go 1.18beta1, or master (gotip);
3. Browse to the package page (http://127.0.0.1:8080/github.com/muhlemmer/godoc_generics_issue) in my case;
4. Find the methods are missing;

[jba]

pkgsite doesn't support generics yet. It will soon, some time before the go 1.18 release.

[jba]

Since this reduces to #48264, closing in favor of that.