1 files changed, 0 insertions, 89 deletions
diff --git a/src/cmd/fix/mapdelete.go b/src/cmd/fix/mapdelete.go
deleted file mode 100644
index db89c7bf4..000000000
--- a/src/cmd/fix/mapdelete.go
+++ /dev/null
@@ -1,89 +0,0 @@
-// 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 "go/ast"
-
-func init() {
-	register(mapdeleteFix)
-}
-
-var mapdeleteFix = fix{
-	"mapdelete",
-	"2011-10-18",
-	mapdelete,
-	`Use delete(m, k) instead of m[k] = 0, false.
-
-http://codereview.appspot.com/5272045
-`,
-}
-
-func mapdelete(f *ast.File) bool {
-	fixed := false
-	walk(f, func(n interface{}) {
-		stmt, ok := n.(*ast.Stmt)
-		if !ok {
-			return
-		}
-		as, ok := (*stmt).(*ast.AssignStmt)
-		if !ok || len(as.Lhs) != 1 || len(as.Rhs) != 2 {
-			return
-		}
-		ix, ok := as.Lhs[0].(*ast.IndexExpr)
-		if !ok {
-			return
-		}
-		if !isTopName(as.Rhs[1], "false") {
-			warn(as.Pos(), "two-element map assignment with non-false second value")
-			return
-		}
-		if !canDrop(as.Rhs[0]) {
-			warn(as.Pos(), "two-element map assignment with non-trivial first value")
-			return
-		}
-		*stmt = &ast.ExprStmt{
-			X: &ast.CallExpr{
-				Fun: &ast.Ident{
-					NamePos: as.Pos(),
-					Name:    "delete",
-				},
-				Args: []ast.Expr{ix.X, ix.Index},
-			},
-		}
-		fixed = true
-	})
-	return fixed
-}
-
-// canDrop reports whether it is safe to drop the
-// evaluation of n from the program.
-// It is very conservative.
-func canDrop(n ast.Expr) bool {
-	switch n := n.(type) {
-	case *ast.Ident, *ast.BasicLit:
-		return true
-	case *ast.ParenExpr:
-		return canDrop(n.X)
-	case *ast.SelectorExpr:
-		return canDrop(n.X)
-	case *ast.CompositeLit:
-		if !canDrop(n.Type) {
-			return false
-		}
-		for _, e := range n.Elts {
-			if !canDrop(e) {
-				return false
-			}
-		}
-		return true
-	case *ast.StarExpr:
-		// Dropping *x is questionable,
-		// but we have to be able to drop (*T)(nil).
-		return canDrop(n.X)
-	case *ast.ArrayType, *ast.ChanType, *ast.FuncType, *ast.InterfaceType, *ast.MapType, *ast.StructType:
-		return true
-	}
-	return false
-}