diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/ast/astutil/rewrite.go')
-rw-r--r-- | vendor/golang.org/x/tools/go/ast/astutil/rewrite.go | 477 |
1 files changed, 0 insertions, 477 deletions
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go deleted file mode 100644 index cf72ea99..00000000 --- a/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go +++ /dev/null @@ -1,477 +0,0 @@ -// Copyright 2017 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 astutil - -import ( - "fmt" - "go/ast" - "reflect" - "sort" -) - -// An ApplyFunc is invoked by Apply for each node n, even if n is nil, -// before and/or after the node's children, using a Cursor describing -// the current node and providing operations on it. -// -// The return value of ApplyFunc controls the syntax tree traversal. -// See Apply for details. -type ApplyFunc func(*Cursor) bool - -// Apply traverses a syntax tree recursively, starting with root, -// and calling pre and post for each node as described below. -// Apply returns the syntax tree, possibly modified. -// -// If pre is not nil, it is called for each node before the node's -// children are traversed (pre-order). If pre returns false, no -// children are traversed, and post is not called for that node. -// -// If post is not nil, and a prior call of pre didn't return false, -// post is called for each node after its children are traversed -// (post-order). If post returns false, traversal is terminated and -// Apply returns immediately. -// -// Only fields that refer to AST nodes are considered children; -// i.e., token.Pos, Scopes, Objects, and fields of basic types -// (strings, etc.) are ignored. -// -// Children are traversed in the order in which they appear in the -// respective node's struct definition. A package's files are -// traversed in the filenames' alphabetical order. -// -func Apply(root ast.Node, pre, post ApplyFunc) (result ast.Node) { - parent := &struct{ ast.Node }{root} - defer func() { - if r := recover(); r != nil && r != abort { - panic(r) - } - result = parent.Node - }() - a := &application{pre: pre, post: post} - a.apply(parent, "Node", nil, root) - return -} - -var abort = new(int) // singleton, to signal termination of Apply - -// A Cursor describes a node encountered during Apply. -// Information about the node and its parent is available -// from the Node, Parent, Name, and Index methods. -// -// If p is a variable of type and value of the current parent node -// c.Parent(), and f is the field identifier with name c.Name(), -// the following invariants hold: -// -// p.f == c.Node() if c.Index() < 0 -// p.f[c.Index()] == c.Node() if c.Index() >= 0 -// -// The methods Replace, Delete, InsertBefore, and InsertAfter -// can be used to change the AST without disrupting Apply. -type Cursor struct { - parent ast.Node - name string - iter *iterator // valid if non-nil - node ast.Node -} - -// Node returns the current Node. -func (c *Cursor) Node() ast.Node { return c.node } - -// Parent returns the parent of the current Node. -func (c *Cursor) Parent() ast.Node { return c.parent } - -// Name returns the name of the parent Node field that contains the current Node. -// If the parent is a *ast.Package and the current Node is a *ast.File, Name returns -// the filename for the current Node. -func (c *Cursor) Name() string { return c.name } - -// Index reports the index >= 0 of the current Node in the slice of Nodes that -// contains it, or a value < 0 if the current Node is not part of a slice. -// The index of the current node changes if InsertBefore is called while -// processing the current node. -func (c *Cursor) Index() int { - if c.iter != nil { - return c.iter.index - } - return -1 -} - -// field returns the current node's parent field value. -func (c *Cursor) field() reflect.Value { - return reflect.Indirect(reflect.ValueOf(c.parent)).FieldByName(c.name) -} - -// Replace replaces the current Node with n. -// The replacement node is not walked by Apply. -func (c *Cursor) Replace(n ast.Node) { - if _, ok := c.node.(*ast.File); ok { - file, ok := n.(*ast.File) - if !ok { - panic("attempt to replace *ast.File with non-*ast.File") - } - c.parent.(*ast.Package).Files[c.name] = file - return - } - - v := c.field() - if i := c.Index(); i >= 0 { - v = v.Index(i) - } - v.Set(reflect.ValueOf(n)) -} - -// Delete deletes the current Node from its containing slice. -// If the current Node is not part of a slice, Delete panics. -// As a special case, if the current node is a package file, -// Delete removes it from the package's Files map. -func (c *Cursor) Delete() { - if _, ok := c.node.(*ast.File); ok { - delete(c.parent.(*ast.Package).Files, c.name) - return - } - - i := c.Index() - if i < 0 { - panic("Delete node not contained in slice") - } - v := c.field() - l := v.Len() - reflect.Copy(v.Slice(i, l), v.Slice(i+1, l)) - v.Index(l - 1).Set(reflect.Zero(v.Type().Elem())) - v.SetLen(l - 1) - c.iter.step-- -} - -// InsertAfter inserts n after the current Node in its containing slice. -// If the current Node is not part of a slice, InsertAfter panics. -// Apply does not walk n. -func (c *Cursor) InsertAfter(n ast.Node) { - i := c.Index() - if i < 0 { - panic("InsertAfter node not contained in slice") - } - v := c.field() - v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) - l := v.Len() - reflect.Copy(v.Slice(i+2, l), v.Slice(i+1, l)) - v.Index(i + 1).Set(reflect.ValueOf(n)) - c.iter.step++ -} - -// InsertBefore inserts n before the current Node in its containing slice. -// If the current Node is not part of a slice, InsertBefore panics. -// Apply will not walk n. -func (c *Cursor) InsertBefore(n ast.Node) { - i := c.Index() - if i < 0 { - panic("InsertBefore node not contained in slice") - } - v := c.field() - v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) - l := v.Len() - reflect.Copy(v.Slice(i+1, l), v.Slice(i, l)) - v.Index(i).Set(reflect.ValueOf(n)) - c.iter.index++ -} - -// application carries all the shared data so we can pass it around cheaply. -type application struct { - pre, post ApplyFunc - cursor Cursor - iter iterator -} - -func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.Node) { - // convert typed nil into untyped nil - if v := reflect.ValueOf(n); v.Kind() == reflect.Ptr && v.IsNil() { - n = nil - } - - // avoid heap-allocating a new cursor for each apply call; reuse a.cursor instead - saved := a.cursor - a.cursor.parent = parent - a.cursor.name = name - a.cursor.iter = iter - a.cursor.node = n - - if a.pre != nil && !a.pre(&a.cursor) { - a.cursor = saved - return - } - - // walk children - // (the order of the cases matches the order of the corresponding node types in go/ast) - switch n := n.(type) { - case nil: - // nothing to do - - // Comments and fields - case *ast.Comment: - // nothing to do - - case *ast.CommentGroup: - if n != nil { - a.applyList(n, "List") - } - - case *ast.Field: - a.apply(n, "Doc", nil, n.Doc) - a.applyList(n, "Names") - a.apply(n, "Type", nil, n.Type) - a.apply(n, "Tag", nil, n.Tag) - a.apply(n, "Comment", nil, n.Comment) - - case *ast.FieldList: - a.applyList(n, "List") - - // Expressions - case *ast.BadExpr, *ast.Ident, *ast.BasicLit: - // nothing to do - - case *ast.Ellipsis: - a.apply(n, "Elt", nil, n.Elt) - - case *ast.FuncLit: - a.apply(n, "Type", nil, n.Type) - a.apply(n, "Body", nil, n.Body) - - case *ast.CompositeLit: - a.apply(n, "Type", nil, n.Type) - a.applyList(n, "Elts") - - case *ast.ParenExpr: - a.apply(n, "X", nil, n.X) - - case *ast.SelectorExpr: - a.apply(n, "X", nil, n.X) - a.apply(n, "Sel", nil, n.Sel) - - case *ast.IndexExpr: - a.apply(n, "X", nil, n.X) - a.apply(n, "Index", nil, n.Index) - - case *ast.SliceExpr: - a.apply(n, "X", nil, n.X) - a.apply(n, "Low", nil, n.Low) - a.apply(n, "High", nil, n.High) - a.apply(n, "Max", nil, n.Max) - - case *ast.TypeAssertExpr: - a.apply(n, "X", nil, n.X) - a.apply(n, "Type", nil, n.Type) - - case *ast.CallExpr: - a.apply(n, "Fun", nil, n.Fun) - a.applyList(n, "Args") - - case *ast.StarExpr: - a.apply(n, "X", nil, n.X) - - case *ast.UnaryExpr: - a.apply(n, "X", nil, n.X) - - case *ast.BinaryExpr: - a.apply(n, "X", nil, n.X) - a.apply(n, "Y", nil, n.Y) - - case *ast.KeyValueExpr: - a.apply(n, "Key", nil, n.Key) - a.apply(n, "Value", nil, n.Value) - - // Types - case *ast.ArrayType: - a.apply(n, "Len", nil, n.Len) - a.apply(n, "Elt", nil, n.Elt) - - case *ast.StructType: - a.apply(n, "Fields", nil, n.Fields) - - case *ast.FuncType: - a.apply(n, "Params", nil, n.Params) - a.apply(n, "Results", nil, n.Results) - - case *ast.InterfaceType: - a.apply(n, "Methods", nil, n.Methods) - - case *ast.MapType: - a.apply(n, "Key", nil, n.Key) - a.apply(n, "Value", nil, n.Value) - - case *ast.ChanType: - a.apply(n, "Value", nil, n.Value) - - // Statements - case *ast.BadStmt: - // nothing to do - - case *ast.DeclStmt: - a.apply(n, "Decl", nil, n.Decl) - - case *ast.EmptyStmt: - // nothing to do - - case *ast.LabeledStmt: - a.apply(n, "Label", nil, n.Label) - a.apply(n, "Stmt", nil, n.Stmt) - - case *ast.ExprStmt: - a.apply(n, "X", nil, n.X) - - case *ast.SendStmt: - a.apply(n, "Chan", nil, n.Chan) - a.apply(n, "Value", nil, n.Value) - - case *ast.IncDecStmt: - a.apply(n, "X", nil, n.X) - - case *ast.AssignStmt: - a.applyList(n, "Lhs") - a.applyList(n, "Rhs") - - case *ast.GoStmt: - a.apply(n, "Call", nil, n.Call) - - case *ast.DeferStmt: - a.apply(n, "Call", nil, n.Call) - - case *ast.ReturnStmt: - a.applyList(n, "Results") - - case *ast.BranchStmt: - a.apply(n, "Label", nil, n.Label) - - case *ast.BlockStmt: - a.applyList(n, "List") - - case *ast.IfStmt: - a.apply(n, "Init", nil, n.Init) - a.apply(n, "Cond", nil, n.Cond) - a.apply(n, "Body", nil, n.Body) - a.apply(n, "Else", nil, n.Else) - - case *ast.CaseClause: - a.applyList(n, "List") - a.applyList(n, "Body") - - case *ast.SwitchStmt: - a.apply(n, "Init", nil, n.Init) - a.apply(n, "Tag", nil, n.Tag) - a.apply(n, "Body", nil, n.Body) - - case *ast.TypeSwitchStmt: - a.apply(n, "Init", nil, n.Init) - a.apply(n, "Assign", nil, n.Assign) - a.apply(n, "Body", nil, n.Body) - - case *ast.CommClause: - a.apply(n, "Comm", nil, n.Comm) - a.applyList(n, "Body") - - case *ast.SelectStmt: - a.apply(n, "Body", nil, n.Body) - - case *ast.ForStmt: - a.apply(n, "Init", nil, n.Init) - a.apply(n, "Cond", nil, n.Cond) - a.apply(n, "Post", nil, n.Post) - a.apply(n, "Body", nil, n.Body) - - case *ast.RangeStmt: - a.apply(n, "Key", nil, n.Key) - a.apply(n, "Value", nil, n.Value) - a.apply(n, "X", nil, n.X) - a.apply(n, "Body", nil, n.Body) - - // Declarations - case *ast.ImportSpec: - a.apply(n, "Doc", nil, n.Doc) - a.apply(n, "Name", nil, n.Name) - a.apply(n, "Path", nil, n.Path) - a.apply(n, "Comment", nil, n.Comment) - - case *ast.ValueSpec: - a.apply(n, "Doc", nil, n.Doc) - a.applyList(n, "Names") - a.apply(n, "Type", nil, n.Type) - a.applyList(n, "Values") - a.apply(n, "Comment", nil, n.Comment) - - case *ast.TypeSpec: - a.apply(n, "Doc", nil, n.Doc) - a.apply(n, "Name", nil, n.Name) - a.apply(n, "Type", nil, n.Type) - a.apply(n, "Comment", nil, n.Comment) - - case *ast.BadDecl: - // nothing to do - - case *ast.GenDecl: - a.apply(n, "Doc", nil, n.Doc) - a.applyList(n, "Specs") - - case *ast.FuncDecl: - a.apply(n, "Doc", nil, n.Doc) - a.apply(n, "Recv", nil, n.Recv) - a.apply(n, "Name", nil, n.Name) - a.apply(n, "Type", nil, n.Type) - a.apply(n, "Body", nil, n.Body) - - // Files and packages - case *ast.File: - a.apply(n, "Doc", nil, n.Doc) - a.apply(n, "Name", nil, n.Name) - a.applyList(n, "Decls") - // Don't walk n.Comments; they have either been walked already if - // they are Doc comments, or they can be easily walked explicitly. - - case *ast.Package: - // collect and sort names for reproducible behavior - var names []string - for name := range n.Files { - names = append(names, name) - } - sort.Strings(names) - for _, name := range names { - a.apply(n, name, nil, n.Files[name]) - } - - default: - panic(fmt.Sprintf("Apply: unexpected node type %T", n)) - } - - if a.post != nil && !a.post(&a.cursor) { - panic(abort) - } - - a.cursor = saved -} - -// An iterator controls iteration over a slice of nodes. -type iterator struct { - index, step int -} - -func (a *application) applyList(parent ast.Node, name string) { - // avoid heap-allocating a new iterator for each applyList call; reuse a.iter instead - saved := a.iter - a.iter.index = 0 - for { - // must reload parent.name each time, since cursor modifications might change it - v := reflect.Indirect(reflect.ValueOf(parent)).FieldByName(name) - if a.iter.index >= v.Len() { - break - } - - // element x may be nil in a bad AST - be cautious - var x ast.Node - if e := v.Index(a.iter.index); e.IsValid() { - x = e.Interface().(ast.Node) - } - - a.iter.step = 1 - a.apply(parent, name, &a.iter, x) - a.iter.index += a.iter.step - } - a.iter = saved -} |