---------- Forwarded message ----------
From: Keynan Pratt <kpr...@atlassian.com>
Date: Sun, Oct 29, 2017 at 5:01 PM
Subject: Re: [go-nuts] go/types#Check is not resolving external package
source positions.
To: roger peppe <rogpe...@gmail.com>
Thanks for the help Roger.
On Sun, Oct 29, 2017 at 5:00 PM, Keynan Pratt <kpr...@atlassian.com> wrote:
> Can confirm the following works as expected:
>
>
> package main
>
> import (
> "fmt"
> "go/parser"
> "go/token"
> "go/ast"
> sourceLoader "golang.org/x/tools/go/loader"
> )
>
> func main() {
> pkgPath := "bitbucket.org/.../test_package"
> dir := "../..//test_package"
>
> fset := token.NewFileSet()
> packages, err := parser.ParseDir(fset, dir, nil, parser.AllErrors)
> if err != nil {
> fmt.Println(err)
> return
> }
>
> for _, p := range packages {
> files := make([]*ast.File, 0, 8)
> for _, file := range p.Files {
> files = append(files, file)
> }
>
> loader := sourceLoader.Config{Fset: fset}
> loader.CreateFromFiles(pkgPath, files...)
> prgm, err := loader.Load()
> if err != nil {
> fmt.Errorf(err.Error())
> }
>
> info := prgm.Created[0].Info
> fmt.Println("\tUsages from ", pkgPath)
> for use := range info.Uses {
> obj := info.Uses[use]
>
> pkgOfUse := obj.Pkg()
> nameOfUse := obj.Name()
> declPos := prgm.Fset.Position(obj.Pos())
> if pkgOfUse == nil {
>
> fmt.Println("Package was nil for obj.id [ ", obj.Id(), " ]")
> continue
> }
> fmt.Printf(
> "\tUsage of %s # %s declared at %s:%d:%d\n",
> pkgOfUse.Path(),
> nameOfUse,
> declPos.Filename, declPos.Line, declPos.Column)
> }
> }
> }
>
>
> On Fri, Oct 27, 2017 at 6:28 PM, roger peppe <rogpe...@gmail.com> wrote:
>
>> As I understand it, the default importer used by go/types looks in the
>> intermediate Go object files, which don't have position information,
>> instead of in the source code. This doesn't appear to be made very
>> clear in the stdlib doc comments, but is mentioned by the types
>> tutorial at https://golang.org/s/types-tutorial#imports That tutorial
>> document also says:
>>
>> "The golang.org/tools/x/go/loader package provides an alternative
>> Importer that addresses some of these problems. It loads a complete
>> program from source, performing cgo preprocessing if necessary,
>> followed by parsing and type-checking."
>>
>> As far as I can see, that's not quite right, as that package doesn't
>> seem to define an importer as such, but if you use it, it has an
>> importer internally that reads from source, so I'd suggest using it
>> rather than go/types directly.
>>
>> I've CC'd Alan Donovan, who can probably expand further on the design
>> choices made here.
>>
>> cheers,
>> rog.
>>
>> On 27 October 2017 at 01:51, <kpr...@atlassian.com> wrote:
>> > I have a simple example file:
>> > ==============================
>> >
>> > package gobbledy_gook
>> >
>> > import (
>> > "log"
>> > turtle "github.com/rs/zerolog/log"
>> > "os"
>> > "github.com/rs/zerolog"
>> > )
>> >
>> > var LOG = turtle.Logger.Output(os.Stdout).Error()
>> >
>> > func g() []zerolog.Logger {
>> > return []zerolog.Logger{}
>> > }
>> >
>> > func DoThings() {
>> > log.Println("proof of concept")
>> > g()[3].Error()
>> > return
>> > }
>> >
>> > ==============================
>> >
>> > I want to use go/ast & go/types to correctly identify the source code
>> > position of the turtle.Logger declaration (.../zerolog/log.go:13:5).
>> >
>> > If I parse only the gobbledy_gook package then the position ends up
>> being
>> > <first file in FileSet>:1:9
>> > If I parse gobbledy_gook & zerolog packages and put them in the fset /
>> list
>> > of files I get an unexpected package error
>> >
>> > Most of the below code is taken from the go/types#Info example code
>> >
>> > func main() {
>> > files := make([]*ast.File, 0, 8)
>> > fset := token.NewFileSet()
>> >
>> > for _, dir := range []string{
>> > "../../test_package",
>> > "go/src/github.com/rs/zerolog",
>> > "go/src/github.com/rs/zerolog/log",
>> > } {
>> > packages, err := parser.ParseDir(fset, dir, nil,
>> parser.AllErrors)
>> > if err != nil {
>> > fmt.Println(err)
>> > return
>> > }
>> >
>> > for _, p := range packages {
>> > for _, file := range p.Files {
>> > files = append(files, file)
>> > }
>> > }
>> > }
>> > fmt.Println("Parse complete")
>> >
>> > info := types.Info{
>> > Types: make(map[ast.Expr]types.TypeAndValue),
>> > Defs: make(map[*ast.Ident]types.Object),
>> > Uses: make(map[*ast.Ident]types.Object),
>> > }
>> > var conf types.Config = types.Config{Importer: importer.Default()}
>> > pkg, err := conf.Check("fib", fset, files, &info)
>> > if err != nil {
>> > log.Println(err.Error())
>> > }
>> > fmt.Println("Check complete")
>> >
>> > // Print package-level variables in initialization order.
>> > fmt.Printf("InitOrder: %v\n\n", info.InitOrder)
>> >
>> > // For each named object, print the line and
>> > // column of its definition and each of its uses.
>> > fmt.Println("Defs and Uses of each named object:")
>> > usesByObj := make(map[types.Object][]string)
>> > for id, obj := range info.Uses {
>> > posn := fset.Position(id.Pos())
>> > lineCol := fmt.Sprintf("%d:%d", posn.Line, posn.Column)
>> > usesByObj[obj] = append(usesByObj[obj], lineCol)
>> > }
>> > var items []string
>> > for obj, uses := range usesByObj {
>> > sort.Strings(uses)
>> > item := fmt.Sprintf("%s:\n defined at %s\n used at %s",
>> > types.ObjectString(obj, types.RelativeTo(pkg)),
>> > fset.Position(obj.Pos()),
>> > strings.Join(uses, ", "))
>> > items = append(items, item)
>> > }
>> > sort.Strings(items) // sort by line:col, in effect
>> > fmt.Println(strings.Join(items, "\n"))
>> > fmt.Println()
>> >
>> > fmt.Println("Types and Values of each expression:")
>> > items = nil
>> > for expr, tv := range info.Types {
>> > var buf bytes.Buffer
>> > posn := fset.Position(expr.Pos())
>> > tvstr := tv.Type.String()
>> > if tv.Value != nil {
>> > tvstr += " = " + tv.Value.String()
>> > }
>> > // line:col | expr | mode : type = value
>> > fmt.Fprintf(&buf, "%s:%2d:%2d | %-19s | %s", posn.Filename,
>> > posn.Line, posn.Column, types.ExprString(expr), tvstr)
>> > items = append(items, buf.String())
>> > }
>> > sort.Strings(items)
>> > fmt.Println(strings.Join(items, "\n"))
>> > }
>> >
>> > --
>> > You received this message because you are subscribed to the Google
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>
>
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