From 83550f0728fa8e2d4be1dd1d2b17a7cedb726c8f Mon Sep 17 00:00:00 2001 From: Robert Hencke Date: Wed, 29 Jun 2011 16:44:47 +1000 Subject: [PATCH] gofix: fixes for os/signal changes Fixes #1971. R=adg, rsc CC=golang-dev https://golang.org/cl/4630056 --- src/cmd/gofix/Makefile | 1 + src/cmd/gofix/fix.go | 159 ++++++++++++++++++++++++++++++++++- src/cmd/gofix/signal.go | 49 +++++++++++ src/cmd/gofix/signal_test.go | 96 +++++++++++++++++++++ 4 files changed, 301 insertions(+), 4 deletions(-) create mode 100644 src/cmd/gofix/signal.go create mode 100644 src/cmd/gofix/signal_test.go diff --git a/src/cmd/gofix/Makefile b/src/cmd/gofix/Makefile index 02d7463078b..e74b639df4f 100644 --- a/src/cmd/gofix/Makefile +++ b/src/cmd/gofix/Makefile @@ -18,6 +18,7 @@ GOFILES=\ osopen.go\ procattr.go\ reflect.go\ + signal.go\ sortslice.go\ stringssplit.go\ typecheck.go\ diff --git a/src/cmd/gofix/fix.go b/src/cmd/gofix/fix.go index 0852ce21edf..c1c5a746ccf 100644 --- a/src/cmd/gofix/fix.go +++ b/src/cmd/gofix/fix.go @@ -10,6 +10,7 @@ import ( "go/token" "os" "strconv" + "strings" ) type fix struct { @@ -258,13 +259,28 @@ func walkBeforeAfter(x interface{}, before, after func(interface{})) { // imports returns true if f imports path. func imports(f *ast.File, path string) bool { + return importSpec(f, path) != nil +} + +// importSpec returns the import spec if f imports path, +// or nil otherwise. +func importSpec(f *ast.File, path string) *ast.ImportSpec { for _, s := range f.Imports { - t, err := strconv.Unquote(s.Path.Value) - if err == nil && t == path { - return true + if importPath(s) == path { + return s } } - return false + return nil +} + +// importPath returns the unquoted import path of s, +// or "" if the path is not properly quoted. +func importPath(s *ast.ImportSpec) string { + t, err := strconv.Unquote(s.Path.Value) + if err == nil { + return t + } + return "" } // isPkgDot returns true if t is the expression "pkg.name" @@ -420,3 +436,138 @@ func newPkgDot(pos token.Pos, pkg, name string) ast.Expr { }, } } + +// addImport adds the import path to the file f, if absent. +func addImport(f *ast.File, path string) { + if imports(f, path) { + return + } + + newImport := &ast.ImportSpec{ + Path: &ast.BasicLit{ + Kind: token.STRING, + Value: strconv.Quote(path), + }, + } + + var impdecl *ast.GenDecl + + // Find an import decl to add to. + for _, decl := range f.Decls { + gen, ok := decl.(*ast.GenDecl) + + if ok && gen.Tok == token.IMPORT { + impdecl = gen + break + } + } + + // No import decl found. Add one. + if impdecl == nil { + impdecl = &ast.GenDecl{ + Tok: token.IMPORT, + } + f.Decls = append(f.Decls, nil) + copy(f.Decls[1:], f.Decls) + f.Decls[0] = impdecl + } + + // Ensure the import decl has parentheses, if needed. + if len(impdecl.Specs) > 0 && !impdecl.Lparen.IsValid() { + impdecl.Lparen = impdecl.Pos() + } + + // Assume the import paths are alphabetically ordered. + // If they are not, the result is ugly, but legal. + insertAt := len(impdecl.Specs) // default to end of specs + for i, spec := range impdecl.Specs { + impspec := spec.(*ast.ImportSpec) + if importPath(impspec) > path { + insertAt = i + break + } + } + + impdecl.Specs = append(impdecl.Specs, nil) + copy(impdecl.Specs[insertAt+1:], impdecl.Specs[insertAt:]) + impdecl.Specs[insertAt] = newImport + + f.Imports = append(f.Imports, newImport) +} + +// deleteImport deletes the import path from the file f, if present. +func deleteImport(f *ast.File, path string) { + oldImport := importSpec(f, path) + + // Find the import node that imports path, if any. + for i, decl := range f.Decls { + gen, ok := decl.(*ast.GenDecl) + if !ok || gen.Tok != token.IMPORT { + continue + } + for j, spec := range gen.Specs { + impspec := spec.(*ast.ImportSpec) + + if oldImport != impspec { + continue + } + + // We found an import spec that imports path. + // Delete it. + copy(gen.Specs[j:], gen.Specs[j+1:]) + gen.Specs = gen.Specs[:len(gen.Specs)-1] + + // If this was the last import spec in this decl, + // delete the decl, too. + if len(gen.Specs) == 0 { + copy(f.Decls[i:], f.Decls[i+1:]) + f.Decls = f.Decls[:len(f.Decls)-1] + } else if len(gen.Specs) == 1 { + gen.Lparen = token.NoPos // drop parens + } + + break + } + } + + // Delete it from f.Imports. + for i, imp := range f.Imports { + if imp == oldImport { + copy(f.Imports[i:], f.Imports[i+1:]) + f.Imports = f.Imports[:len(f.Imports)-1] + break + } + } +} + +func usesImport(f *ast.File, path string) (used bool) { + spec := importSpec(f, path) + if spec == nil { + return + } + + name := spec.Name.String() + switch name { + case "": + // If the package name is not explicitly specified, + // make an educated guess. This is not guaranteed to be correct. + lastSlash := strings.LastIndex(path, "/") + if lastSlash == -1 { + name = path + } else { + name = path[lastSlash+1:] + } + case "_", ".": + // Not sure if this import is used - err on the side of caution. + return true + } + + walk(f, func(n interface{}) { + sel, ok := n.(*ast.SelectorExpr) + if ok && isTopName(sel.X, name) { + used = true + } + }) + + return +} diff --git a/src/cmd/gofix/signal.go b/src/cmd/gofix/signal.go new file mode 100644 index 00000000000..53c338851cb --- /dev/null +++ b/src/cmd/gofix/signal.go @@ -0,0 +1,49 @@ +// 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" + "strings" +) + +func init() { + register(fix{ + "signal", + signal, + `Adapt code to types moved from os/signal to signal. + +http://codereview.appspot.com/4437091 +`, + }) +} + +func signal(f *ast.File) (fixed bool) { + if !imports(f, "os/signal") { + return + } + + walk(f, func(n interface{}) { + s, ok := n.(*ast.SelectorExpr) + + if !ok || !isTopName(s.X, "signal") { + return + } + + sel := s.Sel.String() + if sel == "Signal" || sel == "UnixSignal" || strings.HasPrefix(sel, "SIG") { + s.X = &ast.Ident{Name: "os"} + fixed = true + } + }) + + if fixed { + addImport(f, "os") + if !usesImport(f, "os/signal") { + deleteImport(f, "os/signal") + } + } + return +} diff --git a/src/cmd/gofix/signal_test.go b/src/cmd/gofix/signal_test.go new file mode 100644 index 00000000000..2500e9ceea1 --- /dev/null +++ b/src/cmd/gofix/signal_test.go @@ -0,0 +1,96 @@ +// 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 + +func init() { + addTestCases(signalTests) +} + +var signalTests = []testCase{ + { + Name: "signal.0", + In: `package main + +import ( + _ "a" + "os/signal" + _ "z" +) + +type T1 signal.UnixSignal +type T2 signal.Signal + +func f() { + _ = signal.SIGHUP + _ = signal.Incoming +} +`, + Out: `package main + +import ( + _ "a" + "os" + "os/signal" + _ "z" +) + +type T1 os.UnixSignal +type T2 os.Signal + +func f() { + _ = os.SIGHUP + _ = signal.Incoming +} +`, + }, + { + Name: "signal.1", + In: `package main + +import ( + "os" + "os/signal" +) + +func f() { + var _ os.Error + _ = signal.SIGHUP +} +`, + Out: `package main + +import "os" + + +func f() { + var _ os.Error + _ = os.SIGHUP +} +`, + }, + { + Name: "signal.2", + In: `package main + +import "os" +import "os/signal" + +func f() { + var _ os.Error + _ = signal.SIGHUP +} +`, + Out: `package main + +import "os" + + +func f() { + var _ os.Error + _ = os.SIGHUP +} +`, + }, +}