1// Copyright 2014 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
5package rename
6
7import (
8	"go/ast"
9	"go/token"
10	"go/types"
11	"os"
12	"path/filepath"
13	"reflect"
14	"runtime"
15	"strings"
16	"unicode"
17
18	"golang.org/x/tools/go/ast/astutil"
19)
20
21func objectKind(obj types.Object) string {
22	switch obj := obj.(type) {
23	case *types.PkgName:
24		return "imported package name"
25	case *types.TypeName:
26		return "type"
27	case *types.Var:
28		if obj.IsField() {
29			return "field"
30		}
31	case *types.Func:
32		if obj.Type().(*types.Signature).Recv() != nil {
33			return "method"
34		}
35	}
36	// label, func, var, const
37	return strings.ToLower(strings.TrimPrefix(reflect.TypeOf(obj).String(), "*types."))
38}
39
40func typeKind(T types.Type) string {
41	return strings.ToLower(strings.TrimPrefix(reflect.TypeOf(T.Underlying()).String(), "*types."))
42}
43
44// NB: for renamings, blank is not considered valid.
45func isValidIdentifier(id string) bool {
46	if id == "" || id == "_" {
47		return false
48	}
49	for i, r := range id {
50		if !isLetter(r) && (i == 0 || !isDigit(r)) {
51			return false
52		}
53	}
54	return token.Lookup(id) == token.IDENT
55}
56
57// isLocal reports whether obj is local to some function.
58// Precondition: not a struct field or interface method.
59func isLocal(obj types.Object) bool {
60	// [... 5=stmt 4=func 3=file 2=pkg 1=universe]
61	var depth int
62	for scope := obj.Parent(); scope != nil; scope = scope.Parent() {
63		depth++
64	}
65	return depth >= 4
66}
67
68func isPackageLevel(obj types.Object) bool {
69	return obj.Pkg().Scope().Lookup(obj.Name()) == obj
70}
71
72// -- Plundered from go/scanner: ---------------------------------------
73
74func isLetter(ch rune) bool {
75	return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch == '_' || ch >= 0x80 && unicode.IsLetter(ch)
76}
77
78func isDigit(ch rune) bool {
79	return '0' <= ch && ch <= '9' || ch >= 0x80 && unicode.IsDigit(ch)
80}
81
82// -- Plundered from golang.org/x/tools/cmd/guru -----------------
83
84// sameFile returns true if x and y have the same basename and denote
85// the same file.
86//
87func sameFile(x, y string) bool {
88	if runtime.GOOS == "windows" {
89		x = filepath.ToSlash(x)
90		y = filepath.ToSlash(y)
91	}
92	if x == y {
93		return true
94	}
95	if filepath.Base(x) == filepath.Base(y) { // (optimisation)
96		if xi, err := os.Stat(x); err == nil {
97			if yi, err := os.Stat(y); err == nil {
98				return os.SameFile(xi, yi)
99			}
100		}
101	}
102	return false
103}
104
105func unparen(e ast.Expr) ast.Expr { return astutil.Unparen(e) }
106