go/types: Config.Check says Object.Pkg is in the "go/importer" package #13898

zncoder · 2016-01-10T17:37:29Z

The output of this program is,

use@main.go:39:24: id=Pkg obj=func (interface).Pkg() *go/types.Package in pkg=go/importer

But this looks wrong. Pkg is a method of the interface types.Object, and its package should be "go/types".

package main

import (
    "fmt"
    "go/ast"
    "go/importer"
    "go/parser"
    "go/token"
    "go/types"
    "log"
)

func main() {
    pkg, fn := "main", "main.go"

    fset := token.NewFileSet()
    f, err := parser.ParseFile(fset, fn, src, 0)
    if err != nil {
        log.Fatalf("parse file=%s err=%v", fn, err)
    }

    cfg := types.Config{
        Importer: importer.Default(),
        Error: func(err error) {
            log.Printf("check err=%v", err)
        },
    }

    info := types.Info{
        Uses: make(map[*ast.Ident]types.Object),
    }

    if _, err = cfg.Check(pkg, fset, []*ast.File{f}, &info); err != nil {
        log.Printf("cfg check err=%v", err)
    }

    for id, obj := range info.Uses {
        var pn string
        if obj != nil && obj.Pkg() != nil {
            pn = obj.Pkg().Path()
        }
        if id.Name == "Pkg" {
            fmt.Printf("use@%v: id=%s obj=%v in pkg=%s\n", fset.Position(id.Pos()), id.Name, obj, pn)
        }
    }
}

var src = `package main

import (
    "fmt"
    "go/ast"
    "go/importer"
    "go/parser"
    "go/token"
    "go/types"
    "log"
)

func main() {
    pkg, fn := "main", "main.go"

    fset := token.NewFileSet()
    f, err := parser.ParseFile(fset, fn, src, 0)
    if err != nil {
        log.Fatalf("parse file=%s err=%v", fn, err)
    }

    cfg := types.Config{
        Importer: importer.Default(),
        Error: func(err error) {
            log.Printf("check err=%v", err)
        },
    }

    info := types.Info{
        Uses: make(map[*ast.Ident]types.Object),
    }

    if _, err = cfg.Check(pkg, fset, []*ast.File{f}, &info); err != nil {
        log.Printf("cfg check err=%v", err)
    }

    for id, obj := range info.Uses {
        var pn string
        if obj != nil && obj.Pkg() != nil {
            pn = obj.Pkg().Path()
        }
        if id.Name == "Pkg" {
            fmt.Printf("use@%v: id=%s obj=%v in pkg=%s\n", fset.Position(id.Pos()), id.Name, obj, pn)
        }
    }
}
`

The text was updated successfully, but these errors were encountered:

zncoder · 2016-01-11T19:02:11Z

The go version is, "go version go1.5.2 linux/amd64"

griesemer · 2016-01-11T19:41:55Z

There may be an issue here, but your example is convoluted. For one, it doesn't type-check w/o errors: The source you are providing doesn't define "src". Please simplify the test case.

griesemer · 2016-01-11T21:54:30Z

Simpler:

package main

import (
    "fmt"
    "go/ast"
    "go/importer"
    "go/parser"
    "go/token"
    "go/types"
)

func main() {
    fset := token.NewFileSet()
    f, err := parser.ParseFile(fset, "main.go", nil, 0)
    if err != nil {
        panic(err)
    }

    cfg := types.Config{
        Importer: importer.Default(),
        Error: func(err error) {
            panic(err)
        },
    }

    info := types.Info{
        Uses: make(map[*ast.Ident]types.Object),
    }

    if _, err = cfg.Check("main", fset, []*ast.File{f}, &info); err != nil {
        panic(err)
    }

    for id, obj := range info.Uses {
        if id.Name != "Pkg" {
            //continue
        }
        fmt.Printf("%s: id = %s, obj = %v, obj.Pkg = %v\n", fset.Position(id.Pos()), id.Name, obj, obj.Pkg())
    }
}

griesemer · 2016-01-11T22:54:17Z

This is more subtle. The original (shortened) example works correctly if the import order is changed. In other words, the declaration:

import (
    "fmt"
    "go/ast"
    "go/importer"
    "go/parser"
    "go/token"
    "go/types"
)

leads to:

main.go:38:98: id = Pkg, obj = func (interface).Pkg() *go/types.Package, obj.Pkg = package importer ("go/importer")

But the declaration:

import (
    "fmt"
    "go/ast"
    "go/types"
    "go/importer"
    "go/parser"
    "go/token"
)

(go/types imported before go/importer) leads to the correct output:

main.go:38:98: id = Pkg, obj = func (interface).Pkg() *go/types.Package, obj.Pkg = package types ("go/types")

griesemer · 2016-01-11T23:25:07Z

Complete repro case:

package main

import (
    "fmt"
    "go/ast"
    "go/importer"
    "go/parser"
    "go/token"
    "go/types"
)

var src1 = `
package main

import (
    "go/importer"
    "go/types"
)

func main() {
    var info types.Info
    for _, obj := range info.Uses {
        _ = obj.Pkg()
    }
}
`

var src2 = `
package main

import (
    "go/types"
    "go/importer"
)

func main() {
    var info types.Info
    for _, obj := range info.Uses {
        _ = obj.Pkg()
    }
}
`

func f(src string) {
    fset := token.NewFileSet()
    f, _ := parser.ParseFile(fset, "", src, 0)
    cfg := types.Config{Importer: importer.Default()}
    info := types.Info{Uses: make(map[*ast.Ident]types.Object)}
    cfg.Check("main", fset, []*ast.File{f}, &info)
    for id, obj := range info.Uses {
        if id.Name == "Pkg" {
            fmt.Println(obj.Pkg())
        }
    }
}

func main() {
    f(src1)
    f(src2)
}

The output is:

package importer ("go/importer")
package types ("go/types")

But it should be:

package types ("go/types")
package types ("go/types")

zncoder · 2016-01-12T03:47:36Z

This is fast! Awesome!

gopherbot · 2016-01-13T02:00:13Z

CL https://golang.org/cl/18549 mentions this issue.

This is the equivalent of https://golang.org/cl/18549 for the binary importer (which is usually not used because by default the gc compiler produces the traditional textual export format). For #13898. Change-Id: Idb6b515f2ee49e6d0362c71846994b0bd4dae8f7 Reviewed-on: https://go-review.googlesource.com/18598 Reviewed-by: Alan Donovan <adonovan@google.com> Run-TryBot: Robert Griesemer <gri@golang.org>

griesemer self-assigned this Jan 11, 2016

griesemer added this to the Go1.6 milestone Jan 11, 2016

gopherbot closed this as completed in 7560885 Jan 13, 2016

golang locked and limited conversation to collaborators Jan 13, 2017

gopherbot added the FrozenDueToAge label Jan 13, 2017

rsc unassigned griesemer Jun 23, 2022

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go/types: Config.Check says Object.Pkg is in the "go/importer" package #13898

go/types: Config.Check says Object.Pkg is in the "go/importer" package #13898

zncoder commented Jan 10, 2016

zncoder commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

zncoder commented Jan 12, 2016

gopherbot commented Jan 13, 2016

go/types: Config.Check says Object.Pkg is in the "go/importer" package #13898

go/types: Config.Check says Object.Pkg is in the "go/importer" package #13898

Comments

zncoder commented Jan 10, 2016

zncoder commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

griesemer commented Jan 11, 2016

zncoder commented Jan 12, 2016

gopherbot commented Jan 13, 2016