Generate call graph for packages that depends on Go 1.16

[suntong]

Hi,

• My Go is go-1.15, and
• I downloaded github.com/xo/xo which needs Go 1.16 to compile and
• I want to use go-callvis to generate call graph for it, but

This is what I got:

$ go-callvis -ignore embed,io/fs .
templates/templates.go:6:2: cannot find package "embed" in any of:
        /usr/lib/go-1.15/src/embed (from $GOROOT)
        /path/to/Go/src/embed (from $GOPATH)
templates/templates.go:8:2: cannot find package "io/fs" in any of:
        /usr/lib/go-1.15/src/io/fs (from $GOROOT)
        /path/to/Go/src/io/fs (from $GOPATH)
/path/to/Go/src/github.com/xo/xo/templates/templates.go:6:2: could not import embed (invalid package name: "")
/path/to/Go/src/github.com/xo/xo/templates/templates.go:8:2: could not import io/fs (invalid package name: "")
/path/to/Go/src/github.com/xo/xo/cmd/cmd.go:231:53: DirFS not declared by package os
. . .

I've already use -ignore embed,io/fs to tell go-callvis to ignore embed,io/fs, but why it is still trying to work on it?

Internally, how does thing work? E.g, if I got one go-callvis compiled with go-1.16, would it understand packages that depends on Go 1.16, while my go is still 1.15?

thanks

[ondrajz]

The call graph analysis happens for the source code and since it uses some internal Go libraries it will use the ones installed to resolve the call graph. The project you ran it for requires go 1.16 so to build the call graph you will need go 1.16 too.

[suntong]

OK, Thanks. So

• I might not need go-callvis to be compiled with go-1.16, but
• I need go-1.16 environment to generate call graph for packages that needs Go 1.16,

right?

[ondrajz]

Yes, that is correct. Try it and let me know if you are still having issues.

[suntong]

Thanks! will do.