| 1 | // Copyright 2021 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | //go:build ignore |
| 6 | // +build ignore |
| 7 | |
| 8 | // copytermlist.go copies the term list algorithm from GOROOT/src/go/types. |
| 9 | |
| 10 | package main |
| 11 | |
| 12 | import ( |
| 13 | "bytes" |
| 14 | "fmt" |
| 15 | "go/ast" |
| 16 | "go/format" |
| 17 | "go/parser" |
| 18 | "go/token" |
| 19 | "os" |
| 20 | "path/filepath" |
| 21 | "reflect" |
| 22 | "runtime" |
| 23 | "strings" |
| 24 | |
| 25 | "golang.org/x/tools/go/ast/astutil" |
| 26 | ) |
| 27 | |
| 28 | func main() { |
| 29 | if err := doCopy(); err != nil { |
| 30 | fmt.Fprintf(os.Stderr, "error copying from go/types: %v", err) |
| 31 | os.Exit(1) |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | func doCopy() error { |
| 36 | dir := filepath.Join(runtime.GOROOT(), "src", "go", "types") |
| 37 | for _, name := range []string{"typeterm.go", "termlist.go"} { |
| 38 | path := filepath.Join(dir, name) |
| 39 | fset := token.NewFileSet() |
| 40 | file, err := parser.ParseFile(fset, path, nil, parser.ParseComments) |
| 41 | if err != nil { |
| 42 | return err |
| 43 | } |
| 44 | file.Name.Name = "typeparams" |
| 45 | file.Doc = &ast.CommentGroup{List: []*ast.Comment{{Text: "DO NOT MODIFY"}}} |
| 46 | var needImport bool |
| 47 | selectorType := reflect.TypeOf((*ast.SelectorExpr)(nil)) |
| 48 | astutil.Apply(file, func(c *astutil.Cursor) bool { |
| 49 | if id, _ := c.Node().(*ast.Ident); id != nil { |
| 50 | // Check if this ident should be qualified with types. For simplicity, |
| 51 | // assume the copied files do not themselves contain any exported |
| 52 | // symbols. |
| 53 | |
| 54 | // As a simple heuristic, just verify that the ident may be replaced by |
| 55 | // a selector. |
| 56 | if !token.IsExported(id.Name) { |
| 57 | return false |
| 58 | } |
| 59 | v := reflect.TypeOf(c.Parent()).Elem() // ast nodes are all pointers |
| 60 | field, ok := v.FieldByName(c.Name()) |
| 61 | if !ok { |
| 62 | panic("missing field") |
| 63 | } |
| 64 | t := field.Type |
| 65 | if c.Index() > 0 { // => t is a slice |
| 66 | t = t.Elem() |
| 67 | } |
| 68 | if !selectorType.AssignableTo(t) { |
| 69 | return false |
| 70 | } |
| 71 | needImport = true |
| 72 | c.Replace(&ast.SelectorExpr{ |
| 73 | X: &ast.Ident{NamePos: id.NamePos, Name: "types"}, |
| 74 | Sel: &ast.Ident{NamePos: id.NamePos, Name: id.Name, Obj: id.Obj}, |
| 75 | }) |
| 76 | } |
| 77 | return true |
| 78 | }, nil) |
| 79 | if needImport { |
| 80 | astutil.AddImport(fset, file, "go/types") |
| 81 | } |
| 82 | |
| 83 | var b bytes.Buffer |
| 84 | if err := format.Node(&b, fset, file); err != nil { |
| 85 | return err |
| 86 | } |
| 87 | |
| 88 | // Hack in the 'generated' byline. |
| 89 | content := b.String() |
| 90 | header := "// Code generated by copytermlist.go DO NOT EDIT.\n\npackage typeparams" |
| 91 | content = strings.Replace(content, "package typeparams", header, 1) |
| 92 | |
| 93 | if err := os.WriteFile(name, []byte(content), 0644); err != nil { |
| 94 | return err |
| 95 | } |
| 96 | } |
| 97 | return nil |
| 98 | } |
| 99 |
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