godef-jump with named import

[tomatopeel]

import (
        ...
	gx "github.com/whyrusleeping/gx/gxutil"
        ...
)
...
const PkgFileName = gx.PkgFileName

func LoadPackageFile(path string) (*gx.Package, error) {
	if path == PkgFileName {
		root, err := gx.GetPackageRoot()
                ...
	}

So with the above code from https://github.com/whyrusleeping/gx godef works fine

tomato@think01:gx (master) $ godef -f main.go gx.GetPackageRoot
/home/tomato/ipfs/src/github.com/whyrusleeping/gx/gxutil/pm.go:50:6
tomato@think01:gx (master) $ godef -f main.go gx.PkgFileName
/home/tomato/ipfs/src/github.com/whyrusleeping/gx/gxutil/pm.go:22:7

However go-mode.el is not finding the declaration of gx.PkgFileName or gx.GetPackageRoot. I suspect this is because it's not shaving off the "gx." maybe? I'm not sure.

[tomatopeel]

So the problem is here

          (call-process-region (point-min)
                               (point-max)
                               godef-command
                               nil
                               outbuf
                               nil
                               "-i"
                               "-t"
                               "-f"
                               (file-truename (buffer-file-name (go--coverage-origin-buffer)))
                               "-o"
                               (number-to-string (position-bytes point)))

https://github.com/dominikh/go-mode.el/blob/master/go-mode.el#L1470-L1481

This causes the *godef* buffer output to be godef: no declaration found for <the gx.thing we're godef-jump'ing>

If I run godef -t -f <full path to main.go> from the CLI there's no issue.

[tomatopeel]

If I add the -debug flag into the call-process-region call, I get the following:

2017/06/20 13:31:18 exprType tuple:false pkg: *ast.SelectorExpr gx.GetPackageRoot [
2017/06/20 13:31:18 exprType tuple:false pkg: *ast.Ident gx [
2017/06/20 13:31:18 exprType tuple:false pkg: *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil" [
2017/06/20 13:31:18 ] -> 0x0, Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"}
2017/06/20 13:31:18 ] -> 0xc4201fde50, Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"}
2017/06/20 13:31:18 member Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"} 'GetPackageRoot' {
2017/06/20 13:31:18 } -> <nil>
2017/06/20 13:31:18 ] -> 0x0, Type{bad "" <nil> }
godef: no declaration found for gx.GetPackageRoot

Here's the similar command on the CLI (I've realised I can't test the -i flag properly because I'm not sure how Emacs is streaming to godef, is it the same as catting the file through a pipe? I don't know.):

$ godef -debug -t -f /home/tomato/ipfs/src/github.com/whyrusleeping/gx/main.go -o 565
2017/06/20 13:29:14 exprType tuple:false pkg: *ast.SelectorExpr gx.GetPackageRoot [
2017/06/20 13:29:14 exprType tuple:false pkg: *ast.Ident gx [
2017/06/20 13:29:14 exprType tuple:false pkg: *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil" [
2017/06/20 13:29:14 ] -> 0x0, Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"}
2017/06/20 13:29:14 ] -> 0xc420276140, Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"}
2017/06/20 13:29:14 member Type{package "" *ast.ImportSpec gx "github.com/whyrusleeping/gx/gxutil"} 'GetPackageRoot' {
2017/06/20 13:29:14 } -> &{func GetPackageRoot 0xc4203ac3f0 <nil> <nil>}
2017/06/20 13:29:14 exprType tuple:false pkg: *ast.Ident GetPackageRoot [
2017/06/20 13:29:14 exprType tuple:false pkg: *ast.FuncType func() (string, error) [
2017/06/20 13:29:14 ] -> 0x0, Type{type "" *ast.FuncType func() (string, error)}
2017/06/20 13:29:14 ] -> 0xc420138140, Type{func "" *ast.FuncType func() (string, error)}
2017/06/20 13:29:14 ] -> 0xc420138140, Type{func "github.com/whyrusleeping/gx/gxutil" *ast.FuncType func() (string, error)}
/home/tomato/ipfs/src/github.com/whyrusleeping/gx/gxutil/pm.go:50:6
GetPackageRoot func() (string, error)

[jnschaeffer]

Seems to work for me on my machine.

Steps to reproduce (or not):

• go get github.com/whyrusleeping/gx
• In emacs, C-x C-f $GOPATH/src/github.com/whyrusleeping/gx/main.go
• Move cursor to named definition, e.g. var pm *gx.PM
• C-c C-j

Doing so takes me to the definition of PM in gxutil/pm.go, which I believe is the desired behavior.

[tomatopeel]

Figured this out with some help from @jnschaeffer on go-nuts IRC, thanks so much!

It was just that Emacs didn't have my GOPATH env var, added GOPATH to exec-path-from-shell-copy-envs command in my init and it resolved this.