mirror of
https://github.com/golang/go
synced 2024-11-22 04:24:39 -07:00
gofix: add -diff, various fixes and helpers
* add -diff command line option * use scoping information in refersTo, isPkgDot, isPtrPkgDot. * add new scoping-based helpers countUses, rewriteUses, assignsTo, isTopName. * rename rewrite to walk, add walkBeforeAfter. * add toy typechecker, a placeholder for go/types R=gri CC=golang-dev https://golang.org/cl/4285053
This commit is contained in:
Russ Cox
parent
fb175cf77e
commit
877c1892bb
@ -9,6 +9,7 @@ import (
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"go/ast"
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"go/token"
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"os"
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"strconv"
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)
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type fix struct {
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@ -30,272 +31,297 @@ func register(f fix) {
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fixes = append(fixes, f)
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}
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// rewrite walks the AST x, calling visit(y) for each node y in the tree but
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// also with a pointer to each ast.Expr, in a bottom-up traversal.
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func rewrite(x interface{}, visit func(interface{})) {
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switch n := x.(type) {
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case *ast.Expr:
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rewrite(*n, visit)
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// walk traverses the AST x, calling visit(y) for each node y in the tree but
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// also with a pointer to each ast.Expr, ast.Stmt, and *ast.BlockStmt,
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// in a bottom-up traversal.
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func walk(x interface{}, visit func(interface{})) {
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walkBeforeAfter(x, nop, visit)
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}
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// everything else just recurses
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func nop(interface{}) {}
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// walkBeforeAfter is like walk but calls before(x) before traversing
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// x's children and after(x) afterward.
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func walkBeforeAfter(x interface{}, before, after func(interface{})) {
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before(x)
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switch n := x.(type) {
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default:
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panic(fmt.Errorf("unexpected type %T in walk", x))
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panic(fmt.Errorf("unexpected type %T in walkBeforeAfter", x))
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case nil:
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// pointers to interfaces
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case *ast.Decl:
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walkBeforeAfter(*n, before, after)
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case *ast.Expr:
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walkBeforeAfter(*n, before, after)
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case *ast.Spec:
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walkBeforeAfter(*n, before, after)
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case *ast.Stmt:
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walkBeforeAfter(*n, before, after)
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// pointers to struct pointers
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case **ast.BlockStmt:
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walkBeforeAfter(*n, before, after)
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case **ast.CallExpr:
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walkBeforeAfter(*n, before, after)
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case **ast.FieldList:
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walkBeforeAfter(*n, before, after)
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case **ast.FuncType:
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walkBeforeAfter(*n, before, after)
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// pointers to slices
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case *[]ast.Stmt:
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walkBeforeAfter(*n, before, after)
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case *[]ast.Expr:
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walkBeforeAfter(*n, before, after)
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case *[]ast.Decl:
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walkBeforeAfter(*n, before, after)
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case *[]ast.Spec:
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walkBeforeAfter(*n, before, after)
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case *[]*ast.File:
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walkBeforeAfter(*n, before, after)
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// These are ordered and grouped to match ../../pkg/go/ast/ast.go
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case *ast.Field:
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rewrite(&n.Type, visit)
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walkBeforeAfter(&n.Type, before, after)
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case *ast.FieldList:
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for _, field := range n.List {
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rewrite(field, visit)
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walkBeforeAfter(field, before, after)
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}
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case *ast.BadExpr:
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case *ast.Ident:
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case *ast.Ellipsis:
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case *ast.BasicLit:
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case *ast.FuncLit:
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rewrite(n.Type, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Type, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.CompositeLit:
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rewrite(&n.Type, visit)
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rewrite(n.Elts, visit)
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walkBeforeAfter(&n.Type, before, after)
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walkBeforeAfter(&n.Elts, before, after)
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case *ast.ParenExpr:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.SelectorExpr:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.IndexExpr:
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rewrite(&n.X, visit)
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rewrite(&n.Index, visit)
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walkBeforeAfter(&n.X, before, after)
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walkBeforeAfter(&n.Index, before, after)
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case *ast.SliceExpr:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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if n.Low != nil {
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rewrite(&n.Low, visit)
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walkBeforeAfter(&n.Low, before, after)
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}
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if n.High != nil {
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rewrite(&n.High, visit)
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walkBeforeAfter(&n.High, before, after)
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}
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case *ast.TypeAssertExpr:
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rewrite(&n.X, visit)
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rewrite(&n.Type, visit)
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walkBeforeAfter(&n.X, before, after)
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walkBeforeAfter(&n.Type, before, after)
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case *ast.CallExpr:
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rewrite(&n.Fun, visit)
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rewrite(n.Args, visit)
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walkBeforeAfter(&n.Fun, before, after)
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walkBeforeAfter(&n.Args, before, after)
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case *ast.StarExpr:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.UnaryExpr:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.BinaryExpr:
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rewrite(&n.X, visit)
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rewrite(&n.Y, visit)
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walkBeforeAfter(&n.X, before, after)
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walkBeforeAfter(&n.Y, before, after)
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case *ast.KeyValueExpr:
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rewrite(&n.Key, visit)
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rewrite(&n.Value, visit)
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walkBeforeAfter(&n.Key, before, after)
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walkBeforeAfter(&n.Value, before, after)
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case *ast.ArrayType:
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rewrite(&n.Len, visit)
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rewrite(&n.Elt, visit)
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walkBeforeAfter(&n.Len, before, after)
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walkBeforeAfter(&n.Elt, before, after)
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case *ast.StructType:
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rewrite(n.Fields, visit)
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walkBeforeAfter(&n.Fields, before, after)
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case *ast.FuncType:
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rewrite(n.Params, visit)
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walkBeforeAfter(&n.Params, before, after)
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if n.Results != nil {
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rewrite(n.Results, visit)
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walkBeforeAfter(&n.Results, before, after)
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}
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case *ast.InterfaceType:
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rewrite(n.Methods, visit)
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walkBeforeAfter(&n.Methods, before, after)
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case *ast.MapType:
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rewrite(&n.Key, visit)
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rewrite(&n.Value, visit)
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walkBeforeAfter(&n.Key, before, after)
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walkBeforeAfter(&n.Value, before, after)
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case *ast.ChanType:
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rewrite(&n.Value, visit)
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walkBeforeAfter(&n.Value, before, after)
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case *ast.BadStmt:
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case *ast.DeclStmt:
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rewrite(n.Decl, visit)
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walkBeforeAfter(&n.Decl, before, after)
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case *ast.EmptyStmt:
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case *ast.LabeledStmt:
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rewrite(n.Stmt, visit)
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walkBeforeAfter(&n.Stmt, before, after)
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case *ast.ExprStmt:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.SendStmt:
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rewrite(&n.Chan, visit)
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rewrite(&n.Value, visit)
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walkBeforeAfter(&n.Chan, before, after)
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walkBeforeAfter(&n.Value, before, after)
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case *ast.IncDecStmt:
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rewrite(&n.X, visit)
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walkBeforeAfter(&n.X, before, after)
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case *ast.AssignStmt:
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rewrite(n.Lhs, visit)
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if len(n.Lhs) == 2 && len(n.Rhs) == 1 {
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rewrite(n.Rhs, visit)
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} else {
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rewrite(n.Rhs, visit)
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}
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walkBeforeAfter(&n.Lhs, before, after)
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walkBeforeAfter(&n.Rhs, before, after)
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case *ast.GoStmt:
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rewrite(n.Call, visit)
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walkBeforeAfter(&n.Call, before, after)
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case *ast.DeferStmt:
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rewrite(n.Call, visit)
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walkBeforeAfter(&n.Call, before, after)
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case *ast.ReturnStmt:
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rewrite(n.Results, visit)
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walkBeforeAfter(&n.Results, before, after)
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case *ast.BranchStmt:
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case *ast.BlockStmt:
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rewrite(n.List, visit)
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walkBeforeAfter(&n.List, before, after)
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case *ast.IfStmt:
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rewrite(n.Init, visit)
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rewrite(&n.Cond, visit)
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rewrite(n.Body, visit)
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rewrite(n.Else, visit)
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walkBeforeAfter(&n.Init, before, after)
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walkBeforeAfter(&n.Cond, before, after)
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walkBeforeAfter(&n.Body, before, after)
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walkBeforeAfter(&n.Else, before, after)
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case *ast.CaseClause:
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rewrite(n.List, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.List, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.SwitchStmt:
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rewrite(n.Init, visit)
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rewrite(&n.Tag, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Init, before, after)
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walkBeforeAfter(&n.Tag, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.TypeSwitchStmt:
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rewrite(n.Init, visit)
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rewrite(n.Assign, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Init, before, after)
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walkBeforeAfter(&n.Assign, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.CommClause:
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rewrite(n.Comm, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Comm, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.SelectStmt:
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.ForStmt:
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rewrite(n.Init, visit)
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rewrite(&n.Cond, visit)
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rewrite(n.Post, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Init, before, after)
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walkBeforeAfter(&n.Cond, before, after)
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walkBeforeAfter(&n.Post, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.RangeStmt:
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rewrite(&n.Key, visit)
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rewrite(&n.Value, visit)
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rewrite(&n.X, visit)
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Key, before, after)
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walkBeforeAfter(&n.Value, before, after)
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walkBeforeAfter(&n.X, before, after)
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walkBeforeAfter(&n.Body, before, after)
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case *ast.ImportSpec:
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case *ast.ValueSpec:
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rewrite(&n.Type, visit)
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rewrite(n.Values, visit)
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walkBeforeAfter(&n.Type, before, after)
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walkBeforeAfter(&n.Values, before, after)
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case *ast.TypeSpec:
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rewrite(&n.Type, visit)
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walkBeforeAfter(&n.Type, before, after)
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case *ast.BadDecl:
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case *ast.GenDecl:
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rewrite(n.Specs, visit)
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walkBeforeAfter(&n.Specs, before, after)
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case *ast.FuncDecl:
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if n.Recv != nil {
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rewrite(n.Recv, visit)
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walkBeforeAfter(&n.Recv, before, after)
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}
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rewrite(n.Type, visit)
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walkBeforeAfter(&n.Type, before, after)
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if n.Body != nil {
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rewrite(n.Body, visit)
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walkBeforeAfter(&n.Body, before, after)
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}
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case *ast.File:
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rewrite(n.Decls, visit)
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walkBeforeAfter(&n.Decls, before, after)
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case *ast.Package:
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for _, file := range n.Files {
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rewrite(file, visit)
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}
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walkBeforeAfter(&n.Files, before, after)
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case []*ast.File:
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for i := range n {
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walkBeforeAfter(&n[i], before, after)
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}
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case []ast.Decl:
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for _, d := range n {
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rewrite(d, visit)
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for i := range n {
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walkBeforeAfter(&n[i], before, after)
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}
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case []ast.Expr:
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for i := range n {
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rewrite(&n[i], visit)
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walkBeforeAfter(&n[i], before, after)
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}
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case []ast.Stmt:
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for _, s := range n {
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rewrite(s, visit)
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for i := range n {
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walkBeforeAfter(&n[i], before, after)
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}
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case []ast.Spec:
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for _, s := range n {
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rewrite(s, visit)
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for i := range n {
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walkBeforeAfter(&n[i], before, after)
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}
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}
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visit(x)
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after(x)
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}
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// imports returns true if f imports path.
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func imports(f *ast.File, path string) bool {
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for _, decl := range f.Decls {
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d, ok := decl.(*ast.GenDecl)
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if !ok {
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continue
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}
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for _, spec := range d.Specs {
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s, ok := spec.(*ast.ImportSpec)
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if !ok {
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continue
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}
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if string(s.Path.Value) == `"`+path+`"` {
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for _, s := range f.Imports {
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t, err := strconv.Unquote(s.Path.Value)
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if err == nil && t == path {
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return true
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}
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}
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}
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return false
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}
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// isPkgDot returns true if t is the expression "pkg.name"
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// where pkg is an imported identifier.
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func isPkgDot(t ast.Expr, pkg, name string) bool {
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sel, ok := t.(*ast.SelectorExpr)
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if !ok {
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return false
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}
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return isTopName(sel.X, pkg) && sel.Sel.String() == name
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return ok && isTopName(sel.X, pkg) && sel.Sel.String() == name
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}
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// isPtrPkgDot returns true if f is the expression "*pkg.name"
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// where pkg is an imported identifier.
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func isPtrPkgDot(t ast.Expr, pkg, name string) bool {
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ptr, ok := t.(*ast.StarExpr)
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if !ok {
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return false
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}
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return isPkgDot(ptr.X, pkg, name)
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return ok && isPkgDot(ptr.X, pkg, name)
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}
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// isTopName returns true if n is a top-level unresolved identifier with the given name.
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func isTopName(n ast.Expr, name string) bool {
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id, ok := n.(*ast.Ident)
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if !ok {
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return false
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}
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return id.Name == name && id.Obj == nil
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return ok && id.Name == name && id.Obj == nil
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}
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// isName returns true if n is an identifier with the given name.
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func isName(n ast.Expr, name string) bool {
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id, ok := n.(*ast.Ident)
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if !ok {
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return false
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}
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return id.String() == name
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return ok && id.String() == name
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}
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// isCall returns true if t is a call to pkg.name.
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func isCall(t ast.Expr, pkg, name string) bool {
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call, ok := t.(*ast.CallExpr)
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return ok && isPkgDot(call.Fun, pkg, name)
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}
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func refersTo(n ast.Node, x *ast.Ident) bool {
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id, ok := n.(*ast.Ident)
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if !ok {
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return false
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}
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return id.String() == x.String()
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// If n is an *ast.Ident, isIdent returns it; otherwise isIdent returns nil.
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func isIdent(n interface{}) *ast.Ident {
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id, _ := n.(*ast.Ident)
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return id
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}
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// refersTo returns true if n is a reference to the same object as x.
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func refersTo(n ast.Node, x *ast.Ident) bool {
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id, ok := n.(*ast.Ident)
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// The test of id.Name == x.Name handles top-level unresolved
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// identifiers, which all have Obj == nil.
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return ok && id.Obj == x.Obj && id.Name == x.Name
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}
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// isBlank returns true if n is the blank identifier.
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func isBlank(n ast.Expr) bool {
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return isName(n, "_")
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}
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// isEmptyString returns true if n is an empty string literal.
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func isEmptyString(n ast.Expr) bool {
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lit, ok := n.(*ast.BasicLit)
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if !ok {
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return false
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}
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if lit.Kind != token.STRING {
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return false
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}
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s := string(lit.Value)
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return s == `""` || s == "``"
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return ok && lit.Kind == token.STRING && len(lit.Value) == 2
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}
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func warn(pos token.Pos, msg string, args ...interface{}) {
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@ -306,3 +332,91 @@ func warn(pos token.Pos, msg string, args ...interface{}) {
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}
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fmt.Fprintf(os.Stderr, msg+"\n", args...)
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}
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// countUses returns the number of uses of the identifier x in scope.
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func countUses(x *ast.Ident, scope []ast.Stmt) int {
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count := 0
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ff := func(n interface{}) {
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if n, ok := n.(ast.Node); ok && refersTo(n, x) {
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count++
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}
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}
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for _, n := range scope {
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walk(n, ff)
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}
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return count
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}
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|
||||
// rewriteUses replaces all uses of the identifier x and !x in scope
|
||||
// with f(x.Pos()) and fnot(x.Pos()).
|
||||
func rewriteUses(x *ast.Ident, f, fnot func(token.Pos) ast.Expr, scope []ast.Stmt) {
|
||||
var lastF ast.Expr
|
||||
ff := func(n interface{}) {
|
||||
ptr, ok := n.(*ast.Expr)
|
||||
if !ok {
|
||||
return
|
||||
}
|
||||
nn := *ptr
|
||||
|
||||
// The child node was just walked and possibly replaced.
|
||||
// If it was replaced and this is a negation, replace with fnot(p).
|
||||
not, ok := nn.(*ast.UnaryExpr)
|
||||
if ok && not.Op == token.NOT && not.X == lastF {
|
||||
*ptr = fnot(nn.Pos())
|
||||
return
|
||||
}
|
||||
if refersTo(nn, x) {
|
||||
lastF = f(nn.Pos())
|
||||
*ptr = lastF
|
||||
}
|
||||
}
|
||||
for _, n := range scope {
|
||||
walk(n, ff)
|
||||
}
|
||||
}
|
||||
|
||||
// assignsTo returns true if any of the code in scope assigns to or takes the address of x.
|
||||
func assignsTo(x *ast.Ident, scope []ast.Stmt) bool {
|
||||
assigned := false
|
||||
ff := func(n interface{}) {
|
||||
if assigned {
|
||||
return
|
||||
}
|
||||
switch n := n.(type) {
|
||||
case *ast.UnaryExpr:
|
||||
// use of &x
|
||||
if n.Op == token.AND && refersTo(n.X, x) {
|
||||
assigned = true
|
||||
return
|
||||
}
|
||||
case *ast.AssignStmt:
|
||||
for _, l := range n.Lhs {
|
||||
if refersTo(l, x) {
|
||||
assigned = true
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
for _, n := range scope {
|
||||
if assigned {
|
||||
break
|
||||
}
|
||||
walk(n, ff)
|
||||
}
|
||||
return assigned
|
||||
}
|
||||
|
||||
// newPkgDot returns an ast.Expr referring to "pkg.name" at position pos.
|
||||
func newPkgDot(pos token.Pos, pkg, name string) ast.Expr {
|
||||
return &ast.SelectorExpr{
|
||||
X: &ast.Ident{
|
||||
NamePos: pos,
|
||||
Name: pkg,
|
||||
},
|
||||
Sel: &ast.Ident{
|
||||
NamePos: pos,
|
||||
Name: name,
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
@ -41,7 +41,7 @@ func httpserver(f *ast.File) bool {
|
||||
if !ok {
|
||||
continue
|
||||
}
|
||||
rewrite(fn.Body, func(n interface{}) {
|
||||
walk(fn.Body, func(n interface{}) {
|
||||
// Want to replace expression sometimes,
|
||||
// so record pointer to it for updating below.
|
||||
ptr, ok := n.(*ast.Expr)
|
||||
|
||||
@ -6,6 +6,7 @@ package main
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"exec"
|
||||
"flag"
|
||||
"fmt"
|
||||
"go/parser"
|
||||
@ -29,8 +30,10 @@ var allowedRewrites = flag.String("r", "",
|
||||
|
||||
var allowed map[string]bool
|
||||
|
||||
var doDiff = flag.Bool("diff", false, "display diffs instead of rewriting files")
|
||||
|
||||
func usage() {
|
||||
fmt.Fprintf(os.Stderr, "usage: gofix [-r fixname,...] [path ...]\n")
|
||||
fmt.Fprintf(os.Stderr, "usage: gofix [-diff] [-r fixname,...] [path ...]\n")
|
||||
flag.PrintDefaults()
|
||||
fmt.Fprintf(os.Stderr, "\nAvailable rewrites are:\n")
|
||||
for _, f := range fixes {
|
||||
@ -85,10 +88,16 @@ const (
|
||||
printerMode = printer.TabIndent | printer.UseSpaces
|
||||
)
|
||||
|
||||
var printConfig = &printer.Config{
|
||||
printerMode,
|
||||
tabWidth,
|
||||
}
|
||||
|
||||
func processFile(filename string, useStdin bool) os.Error {
|
||||
var f *os.File
|
||||
var err os.Error
|
||||
var fixlog bytes.Buffer
|
||||
var buf bytes.Buffer
|
||||
|
||||
if useStdin {
|
||||
f = os.Stdin
|
||||
@ -110,34 +119,77 @@ func processFile(filename string, useStdin bool) os.Error {
|
||||
return err
|
||||
}
|
||||
|
||||
// Apply all fixes to file.
|
||||
newFile := file
|
||||
fixed := false
|
||||
var buf bytes.Buffer
|
||||
for _, fix := range fixes {
|
||||
if allowed != nil && !allowed[fix.desc] {
|
||||
continue
|
||||
}
|
||||
if fix.f(file) {
|
||||
if fix.f(newFile) {
|
||||
fixed = true
|
||||
fmt.Fprintf(&buf, " %s", fix.name)
|
||||
fmt.Fprintf(&fixlog, " %s", fix.name)
|
||||
|
||||
// AST changed.
|
||||
// Print and parse, to update any missing scoping
|
||||
// or position information for subsequent fixers.
|
||||
buf.Reset()
|
||||
_, err = printConfig.Fprint(&buf, fset, newFile)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
newSrc := buf.Bytes()
|
||||
newFile, err = parser.ParseFile(fset, filename, newSrc, parserMode)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
}
|
||||
if !fixed {
|
||||
return nil
|
||||
}
|
||||
fmt.Fprintf(os.Stderr, "%s: fixed %s\n", filename, buf.String()[1:])
|
||||
fmt.Fprintf(os.Stderr, "%s: fixed %s\n", filename, fixlog.String()[1:])
|
||||
|
||||
// Print AST. We did that after each fix, so this appears
|
||||
// redundant, but it is necessary to generate gofmt-compatible
|
||||
// source code in a few cases. The official gofmt style is the
|
||||
// output of the printer run on a standard AST generated by the parser,
|
||||
// but the source we generated inside the loop above is the
|
||||
// output of the printer run on a mangled AST generated by a fixer.
|
||||
buf.Reset()
|
||||
_, err = (&printer.Config{printerMode, tabWidth}).Fprint(&buf, fset, file)
|
||||
_, err = printConfig.Fprint(&buf, fset, newFile)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
newSrc := buf.Bytes()
|
||||
|
||||
if useStdin {
|
||||
os.Stdout.Write(buf.Bytes())
|
||||
if *doDiff {
|
||||
data, err := diff(src, newSrc)
|
||||
if err != nil {
|
||||
return fmt.Errorf("computing diff: %s", err)
|
||||
}
|
||||
fmt.Printf("diff %s fixed/%s\n", filename, filename)
|
||||
os.Stdout.Write(data)
|
||||
return nil
|
||||
}
|
||||
|
||||
return ioutil.WriteFile(f.Name(), buf.Bytes(), 0)
|
||||
if useStdin {
|
||||
os.Stdout.Write(newSrc)
|
||||
return nil
|
||||
}
|
||||
|
||||
return ioutil.WriteFile(f.Name(), newSrc, 0)
|
||||
}
|
||||
|
||||
var gofmtBuf bytes.Buffer
|
||||
|
||||
func gofmt(n interface{}) string {
|
||||
gofmtBuf.Reset()
|
||||
_, err := printConfig.Fprint(&gofmtBuf, fset, n)
|
||||
if err != nil {
|
||||
return "<" + err.String() + ">"
|
||||
}
|
||||
return gofmtBuf.String()
|
||||
}
|
||||
|
||||
func report(err os.Error) {
|
||||
@ -177,3 +229,36 @@ func isGoFile(f *os.FileInfo) bool {
|
||||
// ignore non-Go files
|
||||
return f.IsRegular() && !strings.HasPrefix(f.Name, ".") && strings.HasSuffix(f.Name, ".go")
|
||||
}
|
||||
|
||||
func diff(b1, b2 []byte) (data []byte, err os.Error) {
|
||||
f1, err := ioutil.TempFile("", "gofix")
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer os.Remove(f1.Name())
|
||||
defer f1.Close()
|
||||
|
||||
f2, err := ioutil.TempFile("", "gofix")
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer os.Remove(f2.Name())
|
||||
defer f2.Close()
|
||||
|
||||
f1.Write(b1)
|
||||
f2.Write(b2)
|
||||
|
||||
diffcmd, err := exec.LookPath("diff")
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
c, err := exec.Run(diffcmd, []string{"diff", f1.Name(), f2.Name()}, nil, "",
|
||||
exec.DevNull, exec.Pipe, exec.MergeWithStdout)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer c.Close()
|
||||
|
||||
return ioutil.ReadAll(c.Stdout)
|
||||
}
|
||||
|
||||
@ -6,12 +6,10 @@ package main
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"exec"
|
||||
"go/ast"
|
||||
"go/parser"
|
||||
"go/printer"
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"strings"
|
||||
"testing"
|
||||
)
|
||||
|
||||
@ -28,6 +26,8 @@ func addTestCases(t []testCase) {
|
||||
testCases = append(testCases, t...)
|
||||
}
|
||||
|
||||
func fnop(*ast.File) bool { return false }
|
||||
|
||||
func parseFixPrint(t *testing.T, fn func(*ast.File) bool, desc, in string) (out string, fixed, ok bool) {
|
||||
file, err := parser.ParseFile(fset, desc, in, parserMode)
|
||||
if err != nil {
|
||||
@ -42,7 +42,7 @@ func parseFixPrint(t *testing.T, fn func(*ast.File) bool, desc, in string) (out
|
||||
t.Errorf("%s: printing: %v", desc, err)
|
||||
return
|
||||
}
|
||||
if s := buf.String(); in != s {
|
||||
if s := buf.String(); in != s && fn != fnop {
|
||||
t.Errorf("%s: not gofmt-formatted.\n--- %s\n%s\n--- %s | gofmt\n%s",
|
||||
desc, desc, in, desc, s)
|
||||
tdiff(t, in, s)
|
||||
@ -77,8 +77,17 @@ func TestRewrite(t *testing.T) {
|
||||
continue
|
||||
}
|
||||
|
||||
// reformat to get printing right
|
||||
out, _, ok = parseFixPrint(t, fnop, tt.Name, out)
|
||||
if !ok {
|
||||
continue
|
||||
}
|
||||
|
||||
if out != tt.Out {
|
||||
t.Errorf("%s: incorrect output.\n--- have\n%s\n--- want\n%s", tt.Name, out, tt.Out)
|
||||
t.Errorf("%s: incorrect output.\n", tt.Name)
|
||||
if !strings.HasPrefix(tt.Name, "testdata/") {
|
||||
t.Errorf("--- have\n%s\n--- want\n%s", out, tt.Out)
|
||||
}
|
||||
tdiff(t, out, tt.Out)
|
||||
continue
|
||||
}
|
||||
@ -108,44 +117,10 @@ func TestRewrite(t *testing.T) {
|
||||
}
|
||||
|
||||
func tdiff(t *testing.T, a, b string) {
|
||||
f1, err := ioutil.TempFile("", "gofix")
|
||||
data, err := diff([]byte(a), []byte(b))
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
return
|
||||
}
|
||||
defer os.Remove(f1.Name())
|
||||
defer f1.Close()
|
||||
|
||||
f2, err := ioutil.TempFile("", "gofix")
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
return
|
||||
}
|
||||
defer os.Remove(f2.Name())
|
||||
defer f2.Close()
|
||||
|
||||
f1.Write([]byte(a))
|
||||
f2.Write([]byte(b))
|
||||
|
||||
diffcmd, err := exec.LookPath("diff")
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
return
|
||||
}
|
||||
|
||||
c, err := exec.Run(diffcmd, []string{"diff", f1.Name(), f2.Name()}, nil, "",
|
||||
exec.DevNull, exec.Pipe, exec.MergeWithStdout)
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
return
|
||||
}
|
||||
defer c.Close()
|
||||
|
||||
data, err := ioutil.ReadAll(c.Stdout)
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
return
|
||||
}
|
||||
|
||||
t.Error(string(data))
|
||||
}
|
||||
|
||||
@ -47,7 +47,7 @@ func netdial(f *ast.File) bool {
|
||||
}
|
||||
|
||||
fixed := false
|
||||
rewrite(f, func(n interface{}) {
|
||||
walk(f, func(n interface{}) {
|
||||
call, ok := n.(*ast.CallExpr)
|
||||
if !ok || !isPkgDot(call.Fun, "net", "Dial") || len(call.Args) != 3 {
|
||||
return
|
||||
@ -70,7 +70,7 @@ func tlsdial(f *ast.File) bool {
|
||||
}
|
||||
|
||||
fixed := false
|
||||
rewrite(f, func(n interface{}) {
|
||||
walk(f, func(n interface{}) {
|
||||
call, ok := n.(*ast.CallExpr)
|
||||
if !ok || !isPkgDot(call.Fun, "tls", "Dial") || len(call.Args) != 4 {
|
||||
return
|
||||
@ -94,7 +94,7 @@ func netlookup(f *ast.File) bool {
|
||||
}
|
||||
|
||||
fixed := false
|
||||
rewrite(f, func(n interface{}) {
|
||||
walk(f, func(n interface{}) {
|
||||
as, ok := n.(*ast.AssignStmt)
|
||||
if !ok || len(as.Lhs) != 3 || len(as.Rhs) != 1 {
|
||||
return
|
||||
|
||||
@ -27,7 +27,7 @@ func osopen(f *ast.File) bool {
|
||||
}
|
||||
|
||||
fixed := false
|
||||
rewrite(f, func(n interface{}) {
|
||||
walk(f, func(n interface{}) {
|
||||
// Rename O_CREAT to O_CREATE.
|
||||
if expr, ok := n.(ast.Expr); ok && isPkgDot(expr, "os", "O_CREAT") {
|
||||
expr.(*ast.SelectorExpr).Sel.Name = "O_CREATE"
|
||||
|
||||
@ -28,7 +28,7 @@ func procattr(f *ast.File) bool {
|
||||
}
|
||||
|
||||
fixed := false
|
||||
rewrite(f, func(n interface{}) {
|
||||
walk(f, func(n interface{}) {
|
||||
call, ok := n.(*ast.CallExpr)
|
||||
if !ok || len(call.Args) != 5 {
|
||||
return
|
||||
|
||||
579
src/cmd/gofix/typecheck.go
Normal file
579
src/cmd/gofix/typecheck.go
Normal file
@ -0,0 +1,579 @@
|
||||
// Copyright 2011 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 main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"go/ast"
|
||||
"go/token"
|
||||
"os"
|
||||
"reflect"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// Partial type checker.
|
||||
//
|
||||
// The fact that it is partial is very important: the input is
|
||||
// an AST and a description of some type information to
|
||||
// assume about one or more packages, but not all the
|
||||
// packages that the program imports. The checker is
|
||||
// expected to do as much as it can with what it has been
|
||||
// given. There is not enough information supplied to do
|
||||
// a full type check, but the type checker is expected to
|
||||
// apply information that can be derived from variable
|
||||
// declarations, function and method returns, and type switches
|
||||
// as far as it can, so that the caller can still tell the types
|
||||
// of expression relevant to a particular fix.
|
||||
//
|
||||
// TODO(rsc,gri): Replace with go/typechecker.
|
||||
// Doing that could be an interesting test case for go/typechecker:
|
||||
// the constraints about working with partial information will
|
||||
// likely exercise it in interesting ways. The ideal interface would
|
||||
// be to pass typecheck a map from importpath to package API text
|
||||
// (Go source code), but for now we use data structures (TypeConfig, Type).
|
||||
//
|
||||
// The strings mostly use gofmt form.
|
||||
//
|
||||
// A Field or FieldList has as its type a comma-separated list
|
||||
// of the types of the fields. For example, the field list
|
||||
// x, y, z int
|
||||
// has type "int, int, int".
|
||||
|
||||
// The prefix "type " is the type of a type.
|
||||
// For example, given
|
||||
// var x int
|
||||
// type T int
|
||||
// x's type is "int" but T's type is "type int".
|
||||
// mkType inserts the "type " prefix.
|
||||
// getType removes it.
|
||||
// isType tests for it.
|
||||
|
||||
func mkType(t string) string {
|
||||
return "type " + t
|
||||
}
|
||||
|
||||
func getType(t string) string {
|
||||
if !isType(t) {
|
||||
return ""
|
||||
}
|
||||
return t[len("type "):]
|
||||
}
|
||||
|
||||
func isType(t string) bool {
|
||||
return strings.HasPrefix(t, "type ")
|
||||
}
|
||||
|
||||
// TypeConfig describes the universe of relevant types.
|
||||
// For ease of creation, the types are all referred to by string
|
||||
// name (e.g., "reflect.Value"). TypeByName is the only place
|
||||
// where the strings are resolved.
|
||||
|
||||
type TypeConfig struct {
|
||||
Type map[string]*Type
|
||||
Var map[string]string
|
||||
Func map[string]string
|
||||
}
|
||||
|
||||
// typeof returns the type of the given name, which may be of
|
||||
// the form "x" or "p.X".
|
||||
func (cfg *TypeConfig) typeof(name string) string {
|
||||
if cfg.Var != nil {
|
||||
if t := cfg.Var[name]; t != "" {
|
||||
return t
|
||||
}
|
||||
}
|
||||
if cfg.Func != nil {
|
||||
if t := cfg.Func[name]; t != "" {
|
||||
return "func()" + t
|
||||
}
|
||||
}
|
||||
return ""
|
||||
}
|
||||
|
||||
// Type describes the Fields and Methods of a type.
|
||||
// If the field or method cannot be found there, it is next
|
||||
// looked for in the Embed list.
|
||||
type Type struct {
|
||||
Field map[string]string // map field name to type
|
||||
Method map[string]string // map method name to comma-separated return types
|
||||
Embed []string // list of types this type embeds (for extra methods)
|
||||
}
|
||||
|
||||
// dot returns the type of "typ.name", making its decision
|
||||
// using the type information in cfg.
|
||||
func (typ *Type) dot(cfg *TypeConfig, name string) string {
|
||||
if typ.Field != nil {
|
||||
if t := typ.Field[name]; t != "" {
|
||||
return t
|
||||
}
|
||||
}
|
||||
if typ.Method != nil {
|
||||
if t := typ.Method[name]; t != "" {
|
||||
return t
|
||||
}
|
||||
}
|
||||
|
||||
for _, e := range typ.Embed {
|
||||
etyp := cfg.Type[e]
|
||||
if etyp != nil {
|
||||
if t := etyp.dot(cfg, name); t != "" {
|
||||
return t
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return ""
|
||||
}
|
||||
|
||||
// typecheck type checks the AST f assuming the information in cfg.
|
||||
// It returns a map from AST nodes to type information in gofmt string form.
|
||||
func typecheck(cfg *TypeConfig, f *ast.File) map[interface{}]string {
|
||||
typeof := make(map[interface{}]string)
|
||||
|
||||
// gather function declarations
|
||||
for _, decl := range f.Decls {
|
||||
fn, ok := decl.(*ast.FuncDecl)
|
||||
if !ok {
|
||||
continue
|
||||
}
|
||||
typecheck1(cfg, fn.Type, typeof)
|
||||
t := typeof[fn.Type]
|
||||
if fn.Recv != nil {
|
||||
// The receiver must be a type.
|
||||
rcvr := typeof[fn.Recv]
|
||||
if !isType(rcvr) {
|
||||
if len(fn.Recv.List) != 1 {
|
||||
continue
|
||||
}
|
||||
rcvr = mkType(gofmt(fn.Recv.List[0].Type))
|
||||
typeof[fn.Recv.List[0].Type] = rcvr
|
||||
}
|
||||
rcvr = getType(rcvr)
|
||||
if rcvr != "" && rcvr[0] == '*' {
|
||||
rcvr = rcvr[1:]
|
||||
}
|
||||
typeof[rcvr+"."+fn.Name.Name] = t
|
||||
} else {
|
||||
if isType(t) {
|
||||
t = getType(t)
|
||||
} else {
|
||||
t = gofmt(fn.Type)
|
||||
}
|
||||
typeof[fn.Name] = t
|
||||
|
||||
// Record typeof[fn.Name.Obj] for future references to fn.Name.
|
||||
typeof[fn.Name.Obj] = t
|
||||
}
|
||||
}
|
||||
|
||||
typecheck1(cfg, f, typeof)
|
||||
return typeof
|
||||
}
|
||||
|
||||
func makeExprList(a []*ast.Ident) []ast.Expr {
|
||||
var b []ast.Expr
|
||||
for _, x := range a {
|
||||
b = append(b, x)
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
// Typecheck1 is the recursive form of typecheck.
|
||||
// It is like typecheck but adds to the information in typeof
|
||||
// instead of allocating a new map.
|
||||
func typecheck1(cfg *TypeConfig, f interface{}, typeof map[interface{}]string) {
|
||||
// set sets the type of n to typ.
|
||||
// If isDecl is true, n is being declared.
|
||||
set := func(n ast.Expr, typ string, isDecl bool) {
|
||||
if typeof[n] != "" || typ == "" {
|
||||
return
|
||||
}
|
||||
typeof[n] = typ
|
||||
|
||||
// If we obtained typ from the declaration of x
|
||||
// propagate the type to all the uses.
|
||||
// The !isDecl case is a cheat here, but it makes
|
||||
// up in some cases for not paying attention to
|
||||
// struct fields. The real type checker will be
|
||||
// more accurate so we won't need the cheat.
|
||||
if id, ok := n.(*ast.Ident); ok && id.Obj != nil && (isDecl || typeof[id.Obj] == "") {
|
||||
typeof[id.Obj] = typ
|
||||
}
|
||||
}
|
||||
|
||||
// Type-check an assignment lhs = rhs.
|
||||
// If isDecl is true, this is := so we can update
|
||||
// the types of the objects that lhs refers to.
|
||||
typecheckAssign := func(lhs, rhs []ast.Expr, isDecl bool) {
|
||||
if len(lhs) > 1 && len(rhs) == 1 {
|
||||
if _, ok := rhs[0].(*ast.CallExpr); ok {
|
||||
t := split(typeof[rhs[0]])
|
||||
// Lists should have same length but may not; pair what can be paired.
|
||||
for i := 0; i < len(lhs) && i < len(t); i++ {
|
||||
set(lhs[i], t[i], isDecl)
|
||||
}
|
||||
return
|
||||
}
|
||||
}
|
||||
if len(lhs) == 1 && len(rhs) == 2 {
|
||||
// x = y, ok
|
||||
rhs = rhs[:1]
|
||||
} else if len(lhs) == 2 && len(rhs) == 1 {
|
||||
// x, ok = y
|
||||
lhs = lhs[:1]
|
||||
}
|
||||
|
||||
// Match as much as we can.
|
||||
for i := 0; i < len(lhs) && i < len(rhs); i++ {
|
||||
x, y := lhs[i], rhs[i]
|
||||
if typeof[y] != "" {
|
||||
set(x, typeof[y], isDecl)
|
||||
} else {
|
||||
set(y, typeof[x], false)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// The main type check is a recursive algorithm implemented
|
||||
// by walkBeforeAfter(n, before, after).
|
||||
// Most of it is bottom-up, but in a few places we need
|
||||
// to know the type of the function we are checking.
|
||||
// The before function records that information on
|
||||
// the curfn stack.
|
||||
var curfn []*ast.FuncType
|
||||
|
||||
before := func(n interface{}) {
|
||||
// push function type on stack
|
||||
switch n := n.(type) {
|
||||
case *ast.FuncDecl:
|
||||
curfn = append(curfn, n.Type)
|
||||
case *ast.FuncLit:
|
||||
curfn = append(curfn, n.Type)
|
||||
}
|
||||
}
|
||||
|
||||
// After is the real type checker.
|
||||
after := func(n interface{}) {
|
||||
if n == nil {
|
||||
return
|
||||
}
|
||||
if false && reflect.Typeof(n).Kind() == reflect.Ptr { // debugging trace
|
||||
defer func() {
|
||||
if t := typeof[n]; t != "" {
|
||||
pos := fset.Position(n.(ast.Node).Pos())
|
||||
fmt.Fprintf(os.Stderr, "%s: typeof[%s] = %s\n", pos.String(), gofmt(n), t)
|
||||
}
|
||||
}()
|
||||
}
|
||||
|
||||
switch n := n.(type) {
|
||||
case *ast.FuncDecl, *ast.FuncLit:
|
||||
// pop function type off stack
|
||||
curfn = curfn[:len(curfn)-1]
|
||||
|
||||
case *ast.FuncType:
|
||||
typeof[n] = mkType(joinFunc(split(typeof[n.Params]), split(typeof[n.Results])))
|
||||
|
||||
case *ast.FieldList:
|
||||
// Field list is concatenation of sub-lists.
|
||||
t := ""
|
||||
for _, field := range n.List {
|
||||
if t != "" {
|
||||
t += ", "
|
||||
}
|
||||
t += typeof[field]
|
||||
}
|
||||
typeof[n] = t
|
||||
|
||||
case *ast.Field:
|
||||
// Field is one instance of the type per name.
|
||||
all := ""
|
||||
t := typeof[n.Type]
|
||||
if !isType(t) {
|
||||
// Create a type, because it is typically *T or *p.T
|
||||
// and we might care about that type.
|
||||
t = mkType(gofmt(n.Type))
|
||||
typeof[n.Type] = t
|
||||
}
|
||||
t = getType(t)
|
||||
if len(n.Names) == 0 {
|
||||
all = t
|
||||
} else {
|
||||
for _, id := range n.Names {
|
||||
if all != "" {
|
||||
all += ", "
|
||||
}
|
||||
all += t
|
||||
typeof[id.Obj] = t
|
||||
typeof[id] = t
|
||||
}
|
||||
}
|
||||
typeof[n] = all
|
||||
|
||||
case *ast.ValueSpec:
|
||||
// var declaration. Use type if present.
|
||||
if n.Type != nil {
|
||||
t := typeof[n.Type]
|
||||
if !isType(t) {
|
||||
t = mkType(gofmt(n.Type))
|
||||
typeof[n.Type] = t
|
||||
}
|
||||
t = getType(t)
|
||||
for _, id := range n.Names {
|
||||
set(id, t, true)
|
||||
}
|
||||
}
|
||||
// Now treat same as assignment.
|
||||
typecheckAssign(makeExprList(n.Names), n.Values, true)
|
||||
|
||||
case *ast.AssignStmt:
|
||||
typecheckAssign(n.Lhs, n.Rhs, n.Tok == token.DEFINE)
|
||||
|
||||
case *ast.Ident:
|
||||
// Identifier can take its type from underlying object.
|
||||
if t := typeof[n.Obj]; t != "" {
|
||||
typeof[n] = t
|
||||
}
|
||||
|
||||
case *ast.SelectorExpr:
|
||||
// Field or method.
|
||||
name := n.Sel.Name
|
||||
if t := typeof[n.X]; t != "" {
|
||||
if strings.HasPrefix(t, "*") {
|
||||
t = t[1:] // implicit *
|
||||
}
|
||||
if typ := cfg.Type[t]; typ != nil {
|
||||
if t := typ.dot(cfg, name); t != "" {
|
||||
typeof[n] = t
|
||||
return
|
||||
}
|
||||
}
|
||||
tt := typeof[t+"."+name]
|
||||
if isType(tt) {
|
||||
typeof[n] = getType(tt)
|
||||
return
|
||||
}
|
||||
}
|
||||
// Package selector.
|
||||
if x, ok := n.X.(*ast.Ident); ok && x.Obj == nil {
|
||||
str := x.Name + "." + name
|
||||
if cfg.Type[str] != nil {
|
||||
typeof[n] = mkType(str)
|
||||
return
|
||||
}
|
||||
if t := cfg.typeof(x.Name + "." + name); t != "" {
|
||||
typeof[n] = t
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
case *ast.CallExpr:
|
||||
// make(T) has type T.
|
||||
if isTopName(n.Fun, "make") && len(n.Args) >= 1 {
|
||||
typeof[n] = gofmt(n.Args[0])
|
||||
return
|
||||
}
|
||||
// Otherwise, use type of function to determine arguments.
|
||||
t := typeof[n.Fun]
|
||||
in, out := splitFunc(t)
|
||||
if in == nil && out == nil {
|
||||
return
|
||||
}
|
||||
typeof[n] = join(out)
|
||||
for i, arg := range n.Args {
|
||||
if i >= len(in) {
|
||||
break
|
||||
}
|
||||
if typeof[arg] == "" {
|
||||
typeof[arg] = in[i]
|
||||
}
|
||||
}
|
||||
|
||||
case *ast.TypeAssertExpr:
|
||||
// x.(type) has type of x.
|
||||
if n.Type == nil {
|
||||
typeof[n] = typeof[n.X]
|
||||
return
|
||||
}
|
||||
// x.(T) has type T.
|
||||
if t := typeof[n.Type]; isType(t) {
|
||||
typeof[n] = getType(t)
|
||||
}
|
||||
|
||||
case *ast.SliceExpr:
|
||||
// x[i:j] has type of x.
|
||||
typeof[n] = typeof[n.X]
|
||||
|
||||
case *ast.IndexExpr:
|
||||
// x[i] has key type of x's type.
|
||||
t := typeof[n.X]
|
||||
if strings.HasPrefix(t, "[") || strings.HasPrefix(t, "map[") {
|
||||
// Lazy: assume there are no nested [] in the array
|
||||
// length or map key type.
|
||||
if i := strings.Index(t, "]"); i >= 0 {
|
||||
typeof[n] = t[i+1:]
|
||||
}
|
||||
}
|
||||
|
||||
case *ast.StarExpr:
|
||||
// *x for x of type *T has type T when x is an expr.
|
||||
// We don't use the result when *x is a type, but
|
||||
// compute it anyway.
|
||||
t := typeof[n.X]
|
||||
if isType(t) {
|
||||
typeof[n] = "type *" + getType(t)
|
||||
} else if strings.HasPrefix(t, "*") {
|
||||
typeof[n] = t[len("*"):]
|
||||
}
|
||||
|
||||
case *ast.UnaryExpr:
|
||||
// &x for x of type T has type *T.
|
||||
t := typeof[n.X]
|
||||
if t != "" && n.Op == token.AND {
|
||||
typeof[n] = "&" + t
|
||||
}
|
||||
|
||||
case *ast.CompositeLit:
|
||||
// T{...} has type T.
|
||||
typeof[n] = gofmt(n.Type)
|
||||
|
||||
case *ast.ParenExpr:
|
||||
// (x) has type of x.
|
||||
typeof[n] = typeof[n.X]
|
||||
|
||||
case *ast.TypeSwitchStmt:
|
||||
// Type of variable changes for each case in type switch,
|
||||
// but go/parser generates just one variable.
|
||||
// Repeat type check for each case with more precise
|
||||
// type information.
|
||||
as, ok := n.Assign.(*ast.AssignStmt)
|
||||
if !ok {
|
||||
return
|
||||
}
|
||||
varx, ok := as.Lhs[0].(*ast.Ident)
|
||||
if !ok {
|
||||
return
|
||||
}
|
||||
t := typeof[varx]
|
||||
for _, cas := range n.Body.List {
|
||||
cas := cas.(*ast.CaseClause)
|
||||
if len(cas.List) == 1 {
|
||||
// Variable has specific type only when there is
|
||||
// exactly one type in the case list.
|
||||
if tt := typeof[cas.List[0]]; isType(tt) {
|
||||
tt = getType(tt)
|
||||
typeof[varx] = tt
|
||||
typeof[varx.Obj] = tt
|
||||
typecheck1(cfg, cas.Body, typeof)
|
||||
}
|
||||
}
|
||||
}
|
||||
// Restore t.
|
||||
typeof[varx] = t
|
||||
typeof[varx.Obj] = t
|
||||
|
||||
case *ast.ReturnStmt:
|
||||
if len(curfn) == 0 {
|
||||
// Probably can't happen.
|
||||
return
|
||||
}
|
||||
f := curfn[len(curfn)-1]
|
||||
res := n.Results
|
||||
if f.Results != nil {
|
||||
t := split(typeof[f.Results])
|
||||
for i := 0; i < len(res) && i < len(t); i++ {
|
||||
set(res[i], t[i], false)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
walkBeforeAfter(f, before, after)
|
||||
}
|
||||
|
||||
// Convert between function type strings and lists of types.
|
||||
// Using strings makes this a little harder, but it makes
|
||||
// a lot of the rest of the code easier. This will all go away
|
||||
// when we can use go/typechecker directly.
|
||||
|
||||
// splitFunc splits "func(x,y,z) (a,b,c)" into ["x", "y", "z"] and ["a", "b", "c"].
|
||||
func splitFunc(s string) (in, out []string) {
|
||||
if !strings.HasPrefix(s, "func(") {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
i := len("func(") // index of beginning of 'in' arguments
|
||||
nparen := 0
|
||||
for j := i; j < len(s); j++ {
|
||||
switch s[j] {
|
||||
case '(':
|
||||
nparen++
|
||||
case ')':
|
||||
nparen--
|
||||
if nparen < 0 {
|
||||
// found end of parameter list
|
||||
out := strings.TrimSpace(s[j+1:])
|
||||
if len(out) >= 2 && out[0] == '(' && out[len(out)-1] == ')' {
|
||||
out = out[1 : len(out)-1]
|
||||
}
|
||||
return split(s[i:j]), split(out)
|
||||
}
|
||||
}
|
||||
}
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// joinFunc is the inverse of splitFunc.
|
||||
func joinFunc(in, out []string) string {
|
||||
outs := ""
|
||||
if len(out) == 1 {
|
||||
outs = " " + out[0]
|
||||
} else if len(out) > 1 {
|
||||
outs = " (" + join(out) + ")"
|
||||
}
|
||||
return "func(" + join(in) + ")" + outs
|
||||
}
|
||||
|
||||
// split splits "int, float" into ["int", "float"] and splits "" into [].
|
||||
func split(s string) []string {
|
||||
out := []string{}
|
||||
i := 0 // current type being scanned is s[i:j].
|
||||
nparen := 0
|
||||
for j := 0; j < len(s); j++ {
|
||||
switch s[j] {
|
||||
case ' ':
|
||||
if i == j {
|
||||
i++
|
||||
}
|
||||
case '(':
|
||||
nparen++
|
||||
case ')':
|
||||
nparen--
|
||||
if nparen < 0 {
|
||||
// probably can't happen
|
||||
return nil
|
||||
}
|
||||
case ',':
|
||||
if nparen == 0 {
|
||||
if i < j {
|
||||
out = append(out, s[i:j])
|
||||
}
|
||||
i = j + 1
|
||||
}
|
||||
}
|
||||
}
|
||||
if nparen != 0 {
|
||||
// probably can't happen
|
||||
return nil
|
||||
}
|
||||
if i < len(s) {
|
||||
out = append(out, s[i:])
|
||||
}
|
||||
return out
|
||||
}
|
||||
|
||||
// join is the inverse of split.
|
||||
func join(x []string) string {
|
||||
return strings.Join(x, ", ")
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user