+++ /dev/null
-// Copyright 2020 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package source
-
-import (
- "bytes"
- "context"
- "fmt"
- "go/ast"
- "go/printer"
- "go/token"
- "go/types"
- "strings"
-
- "golang.org/x/tools/internal/event"
- "golang.org/x/tools/internal/lsp/debug/tag"
- "golang.org/x/tools/internal/lsp/protocol"
-)
-
-// FormatType returns the detail and kind for a types.Type.
-func FormatType(typ types.Type, qf types.Qualifier) (detail string, kind protocol.CompletionItemKind) {
- if types.IsInterface(typ) {
- detail = "interface{...}"
- kind = protocol.InterfaceCompletion
- } else if _, ok := typ.(*types.Struct); ok {
- detail = "struct{...}"
- kind = protocol.StructCompletion
- } else if typ != typ.Underlying() {
- detail, kind = FormatType(typ.Underlying(), qf)
- } else {
- detail = types.TypeString(typ, qf)
- kind = protocol.ClassCompletion
- }
- return detail, kind
-}
-
-type signature struct {
- name, doc string
- params, results []string
- variadic bool
- needResultParens bool
-}
-
-func (s *signature) Format() string {
- var b strings.Builder
- b.WriteByte('(')
- for i, p := range s.params {
- if i > 0 {
- b.WriteString(", ")
- }
- b.WriteString(p)
- }
- b.WriteByte(')')
-
- // Add space between parameters and results.
- if len(s.results) > 0 {
- b.WriteByte(' ')
- }
- if s.needResultParens {
- b.WriteByte('(')
- }
- for i, r := range s.results {
- if i > 0 {
- b.WriteString(", ")
- }
- b.WriteString(r)
- }
- if s.needResultParens {
- b.WriteByte(')')
- }
- return b.String()
-}
-
-func (s *signature) Params() []string {
- return s.params
-}
-
-// NewBuiltinSignature returns signature for the builtin object with a given
-// name, if a builtin object with the name exists.
-func NewBuiltinSignature(ctx context.Context, snapshot Snapshot, name string) (*signature, error) {
- builtin, err := snapshot.BuiltinPackage(ctx)
- if err != nil {
- return nil, err
- }
- obj := builtin.Package.Scope.Lookup(name)
- if obj == nil {
- return nil, fmt.Errorf("no builtin object for %s", name)
- }
- decl, ok := obj.Decl.(*ast.FuncDecl)
- if !ok {
- return nil, fmt.Errorf("no function declaration for builtin: %s", name)
- }
- if decl.Type == nil {
- return nil, fmt.Errorf("no type for builtin decl %s", decl.Name)
- }
- var variadic bool
- if decl.Type.Params.List != nil {
- numParams := len(decl.Type.Params.List)
- lastParam := decl.Type.Params.List[numParams-1]
- if _, ok := lastParam.Type.(*ast.Ellipsis); ok {
- variadic = true
- }
- }
- params, _ := formatFieldList(ctx, snapshot, decl.Type.Params, variadic)
- results, needResultParens := formatFieldList(ctx, snapshot, decl.Type.Results, false)
- return &signature{
- doc: decl.Doc.Text(),
- name: name,
- needResultParens: needResultParens,
- params: params,
- results: results,
- variadic: variadic,
- }, nil
-}
-
-var replacer = strings.NewReplacer(
- `ComplexType`, `complex128`,
- `FloatType`, `float64`,
- `IntegerType`, `int`,
-)
-
-func formatFieldList(ctx context.Context, snapshot Snapshot, list *ast.FieldList, variadic bool) ([]string, bool) {
- if list == nil {
- return nil, false
- }
- var writeResultParens bool
- var result []string
- for i := 0; i < len(list.List); i++ {
- if i >= 1 {
- writeResultParens = true
- }
- p := list.List[i]
- cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 4}
- b := &bytes.Buffer{}
- if err := cfg.Fprint(b, snapshot.FileSet(), p.Type); err != nil {
- event.Error(ctx, "unable to print type", nil, tag.Type.Of(p.Type))
- continue
- }
- typ := replacer.Replace(b.String())
- if len(p.Names) == 0 {
- result = append(result, typ)
- }
- for _, name := range p.Names {
- if name.Name != "" {
- if i == 0 {
- writeResultParens = true
- }
- result = append(result, fmt.Sprintf("%s %s", name.Name, typ))
- } else {
- result = append(result, typ)
- }
- }
- }
- if variadic {
- result[len(result)-1] = strings.Replace(result[len(result)-1], "[]", "...", 1)
- }
- return result, writeResultParens
-}
-
-// NewSignature returns formatted signature for a types.Signature struct.
-func NewSignature(ctx context.Context, s Snapshot, pkg Package, sig *types.Signature, comment *ast.CommentGroup, qf types.Qualifier) *signature {
- params := make([]string, 0, sig.Params().Len())
- for i := 0; i < sig.Params().Len(); i++ {
- el := sig.Params().At(i)
- typ := FormatVarType(ctx, s, pkg, el, qf)
- p := typ
- if el.Name() != "" {
- p = el.Name() + " " + typ
- }
- params = append(params, p)
- }
- var needResultParens bool
- results := make([]string, 0, sig.Results().Len())
- for i := 0; i < sig.Results().Len(); i++ {
- if i >= 1 {
- needResultParens = true
- }
- el := sig.Results().At(i)
- typ := FormatVarType(ctx, s, pkg, el, qf)
- if el.Name() == "" {
- results = append(results, typ)
- } else {
- if i == 0 {
- needResultParens = true
- }
- results = append(results, el.Name()+" "+typ)
- }
- }
- var doc string
- if comment != nil {
- doc = comment.Text()
- }
- return &signature{
- doc: doc,
- params: params,
- results: results,
- variadic: sig.Variadic(),
- needResultParens: needResultParens,
- }
-}
-
-// FormatVarType formats a *types.Var, accounting for type aliases.
-// To do this, it looks in the AST of the file in which the object is declared.
-// On any errors, it always fallbacks back to types.TypeString.
-func FormatVarType(ctx context.Context, snapshot Snapshot, srcpkg Package, obj *types.Var, qf types.Qualifier) string {
- pgf, pkg, err := FindPosInPackage(snapshot, srcpkg, obj.Pos())
- if err != nil {
- return types.TypeString(obj.Type(), qf)
- }
-
- expr, err := varType(ctx, snapshot, pgf, obj)
- if err != nil {
- return types.TypeString(obj.Type(), qf)
- }
-
- // The type names in the AST may not be correctly qualified.
- // Determine the package name to use based on the package that originated
- // the query and the package in which the type is declared.
- // We then qualify the value by cloning the AST node and editing it.
- clonedInfo := make(map[token.Pos]*types.PkgName)
- qualified := cloneExpr(expr, pkg.GetTypesInfo(), clonedInfo)
-
- // If the request came from a different package than the one in which the
- // types are defined, we may need to modify the qualifiers.
- qualified = qualifyExpr(qualified, srcpkg, pkg, clonedInfo, qf)
- fmted := FormatNode(snapshot.FileSet(), qualified)
- return fmted
-}
-
-// varType returns the type expression for a *types.Var.
-func varType(ctx context.Context, snapshot Snapshot, pgf *ParsedGoFile, obj *types.Var) (ast.Expr, error) {
- posToField, err := snapshot.PosToField(ctx, pgf)
- if err != nil {
- return nil, err
- }
- field := posToField[obj.Pos()]
- if field == nil {
- return nil, fmt.Errorf("no declaration for object %s", obj.Name())
- }
- typ, ok := field.Type.(ast.Expr)
- if !ok {
- return nil, fmt.Errorf("unexpected type for node (%T)", field.Type)
- }
- return typ, nil
-}
-
-// qualifyExpr applies the "pkgName." prefix to any *ast.Ident in the expr.
-func qualifyExpr(expr ast.Expr, srcpkg, pkg Package, clonedInfo map[token.Pos]*types.PkgName, qf types.Qualifier) ast.Expr {
- ast.Inspect(expr, func(n ast.Node) bool {
- switch n := n.(type) {
- case *ast.ArrayType, *ast.ChanType, *ast.Ellipsis,
- *ast.FuncType, *ast.MapType, *ast.ParenExpr,
- *ast.StarExpr, *ast.StructType:
- // These are the only types that are cloned by cloneExpr below,
- // so these are the only types that we can traverse and potentially
- // modify. This is not an ideal approach, but it works for now.
- return true
- case *ast.SelectorExpr:
- // We may need to change any selectors in which the X is a package
- // name and the Sel is exported.
- x, ok := n.X.(*ast.Ident)
- if !ok {
- return false
- }
- obj, ok := clonedInfo[x.Pos()]
- if !ok {
- return false
- }
- pkgName := qf(obj.Imported())
- if pkgName != "" {
- x.Name = pkgName
- }
- return false
- case *ast.Ident:
- if srcpkg == pkg {
- return false
- }
- // Only add the qualifier if the identifier is exported.
- if ast.IsExported(n.Name) {
- pkgName := qf(pkg.GetTypes())
- n.Name = pkgName + "." + n.Name
- }
- }
- return false
- })
- return expr
-}
-
-// cloneExpr only clones expressions that appear in the parameters or return
-// values of a function declaration. The original expression may be returned
-// to the caller in 2 cases:
-// (1) The expression has no pointer fields.
-// (2) The expression cannot appear in an *ast.FuncType, making it
-// unnecessary to clone.
-// This function also keeps track of selector expressions in which the X is a
-// package name and marks them in a map along with their type information, so
-// that this information can be used when rewriting the expression.
-//
-// NOTE: This function is tailored to the use case of qualifyExpr, and should
-// be used with caution.
-func cloneExpr(expr ast.Expr, info *types.Info, clonedInfo map[token.Pos]*types.PkgName) ast.Expr {
- switch expr := expr.(type) {
- case *ast.ArrayType:
- return &ast.ArrayType{
- Lbrack: expr.Lbrack,
- Elt: cloneExpr(expr.Elt, info, clonedInfo),
- Len: expr.Len,
- }
- case *ast.ChanType:
- return &ast.ChanType{
- Arrow: expr.Arrow,
- Begin: expr.Begin,
- Dir: expr.Dir,
- Value: cloneExpr(expr.Value, info, clonedInfo),
- }
- case *ast.Ellipsis:
- return &ast.Ellipsis{
- Ellipsis: expr.Ellipsis,
- Elt: cloneExpr(expr.Elt, info, clonedInfo),
- }
- case *ast.FuncType:
- return &ast.FuncType{
- Func: expr.Func,
- Params: cloneFieldList(expr.Params, info, clonedInfo),
- Results: cloneFieldList(expr.Results, info, clonedInfo),
- }
- case *ast.Ident:
- return cloneIdent(expr)
- case *ast.MapType:
- return &ast.MapType{
- Map: expr.Map,
- Key: cloneExpr(expr.Key, info, clonedInfo),
- Value: cloneExpr(expr.Value, info, clonedInfo),
- }
- case *ast.ParenExpr:
- return &ast.ParenExpr{
- Lparen: expr.Lparen,
- Rparen: expr.Rparen,
- X: cloneExpr(expr.X, info, clonedInfo),
- }
- case *ast.SelectorExpr:
- s := &ast.SelectorExpr{
- Sel: cloneIdent(expr.Sel),
- X: cloneExpr(expr.X, info, clonedInfo),
- }
- if x, ok := expr.X.(*ast.Ident); ok && ast.IsExported(expr.Sel.Name) {
- if obj, ok := info.ObjectOf(x).(*types.PkgName); ok {
- clonedInfo[s.X.Pos()] = obj
- }
- }
- return s
- case *ast.StarExpr:
- return &ast.StarExpr{
- Star: expr.Star,
- X: cloneExpr(expr.X, info, clonedInfo),
- }
- case *ast.StructType:
- return &ast.StructType{
- Struct: expr.Struct,
- Fields: cloneFieldList(expr.Fields, info, clonedInfo),
- Incomplete: expr.Incomplete,
- }
- default:
- return expr
- }
-}
-
-func cloneFieldList(fl *ast.FieldList, info *types.Info, clonedInfo map[token.Pos]*types.PkgName) *ast.FieldList {
- if fl == nil {
- return nil
- }
- if fl.List == nil {
- return &ast.FieldList{
- Closing: fl.Closing,
- Opening: fl.Opening,
- }
- }
- list := make([]*ast.Field, 0, len(fl.List))
- for _, f := range fl.List {
- var names []*ast.Ident
- for _, n := range f.Names {
- names = append(names, cloneIdent(n))
- }
- list = append(list, &ast.Field{
- Comment: f.Comment,
- Doc: f.Doc,
- Names: names,
- Tag: f.Tag,
- Type: cloneExpr(f.Type, info, clonedInfo),
- })
- }
- return &ast.FieldList{
- Closing: fl.Closing,
- Opening: fl.Opening,
- List: list,
- }
-}
-
-func cloneIdent(ident *ast.Ident) *ast.Ident {
- return &ast.Ident{
- NamePos: ident.NamePos,
- Name: ident.Name,
- Obj: ident.Obj,
- }
-}
projects / dotfiles / .git / blobdiff