go: improvements

Add 'go clean'.
Make 'go build' write to pkgname, not a.out.
Make 'go test -c' write to pkgname.test, not test.out.
Make 'go install' write alternate binaries to .../bin/goos_goarch/.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5600048

src/cmd/go/build.go

@@ -14,6 +14,7 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"path"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -113,7 +114,10 @@ func runBuild(cmd *Command, args []string) {
 	}
 
 	if len(pkgs) == 1 && pkgs[0].Name == "main" && *buildO == "" {
-		*buildO = "a.out"
+		_, *buildO = path.Split(pkgs[0].ImportPath)
+		if b.goos == "windows" {
+			*buildO += ".exe"
+		}
 	}
 
 	if *buildO != "" {
@@ -174,10 +178,8 @@ func runInstall(cmd *Command, args []string) {
 type builder struct {
 	work        string               // the temporary work directory (ends in filepath.Separator)
 	arch        string               // e.g., "6"
-	goroot      string               // the $GOROOT
 	goarch      string               // the $GOARCH
 	goos        string               // the $GOOS
-	gobin       string               // the $GOBIN
 	exe         string               // the executable suffix - "" or ".exe"
 	gcflags     []string             // additional flags for Go compiler
 	actionCache map[cacheKey]*action // a cache of already-constructed actions
@@ -231,14 +233,17 @@ const (
 	modeInstall
 )
 
+var (
+	gobin  = build.Path[0].BinDir()
+	goroot = build.Path[0].Path
+)
+
 func (b *builder) init() {
 	var err error
 	b.actionCache = make(map[cacheKey]*action)
 	b.mkdirCache = make(map[string]bool)
 	b.goarch = buildContext.GOARCH
 	b.goos = buildContext.GOOS
-	b.goroot = build.Path[0].Path
-	b.gobin = build.Path[0].BinDir()
 	if b.goos == "windows" {
 		b.exe = ".exe"
 	}
@@ -367,8 +372,6 @@ func (b *builder) action(mode buildMode, depMode buildMode, p *Package) *action
 		a.target = a.objpkg
 		if a.link {
 			// An executable file.
-			// Have to use something other than .a for the suffix.
-			// It is easier on Windows if we use .exe, so use .exe everywhere.
 			// (This is the name of a temporary file.)
 			a.target = a.objdir + "a.out" + b.exe
 		}
@@ -762,7 +765,7 @@ func (b *builder) copyFile(dst, src string, perm os.FileMode) error {
 //	fmtcmd inserts "cd dir\n" before the command.
 //
 //	fmtcmd replaces the value of b.work with $WORK.
-//	fmtcmd replaces the value of b.goroot with $GOROOT.
+//	fmtcmd replaces the value of goroot with $GOROOT.
 //	fmtcmd replaces the value of b.gobin with $GOBIN.
 //
 //	fmtcmd replaces the name of the current directory with dot (.)
@@ -777,9 +780,11 @@ func (b *builder) fmtcmd(dir string, format string, args ...interface{}) string
 			cmd = "cd " + dir + "\n" + cmd
 		}
 	}
+	if b.work != "" {
 		cmd = strings.Replace(cmd, b.work, "$WORK", -1)
-	cmd = strings.Replace(cmd, b.gobin, "$GOBIN", -1)
-	cmd = strings.Replace(cmd, b.goroot, "$GOROOT", -1)
+	}
+	cmd = strings.Replace(cmd, gobin, "$GOBIN", -1)
+	cmd = strings.Replace(cmd, goroot, "$GOROOT", -1)
 	return cmd
 }
 
@@ -976,7 +981,7 @@ func (goToolchain) gc(b *builder, p *Package, obj string, importArgs []string, g
 		gcargs = append(gcargs, "-+")
 	}
 
-	binary := filepath.Join(b.goroot, "bin/go-tool/", b.arch+"g")
+	binary := filepath.Join(goroot, "bin/go-tool/", b.arch+"g")
 	args := stringList(binary, "-o", ofile, b.gcflags, gcargs, importArgs)
 	for _, f := range gofiles {
 		args = append(args, mkAbs(p.Dir, f))
@@ -986,7 +991,7 @@ func (goToolchain) gc(b *builder, p *Package, obj string, importArgs []string, g
 
 func (goToolchain) asm(b *builder, p *Package, obj, ofile, sfile string) error {
 	sfile = mkAbs(p.Dir, sfile)
-	binary := filepath.Join(b.goroot, "bin/go-tool/", b.arch+"a")
+	binary := filepath.Join(goroot, "bin/go-tool/", b.arch+"a")
 	return b.run(p.Dir, p.ImportPath, binary, "-I", obj, "-o", ofile, "-DGOOS_"+b.goos, "-DGOARCH_"+b.goarch, sfile)
 }
 
@@ -999,19 +1004,19 @@ func (goToolchain) pack(b *builder, p *Package, objDir, afile string, ofiles []s
 	for _, f := range ofiles {
 		absOfiles = append(absOfiles, mkAbs(objDir, f))
 	}
-	return b.run(p.Dir, p.ImportPath, filepath.Join(b.goroot, "bin/go-tool/pack"), "grc", mkAbs(objDir, afile), absOfiles)
+	return b.run(p.Dir, p.ImportPath, filepath.Join(goroot, "bin/go-tool/pack"), "grc", mkAbs(objDir, afile), absOfiles)
 }
 
 func (goToolchain) ld(b *builder, p *Package, out string, allactions []*action, mainpkg string, ofiles []string) error {
 	importArgs := b.includeArgs("-L", allactions)
-	binary := filepath.Join(b.goroot, "bin/go-tool/", b.arch+"l")
+	binary := filepath.Join(goroot, "bin/go-tool/", b.arch+"l")
 	return b.run(p.Dir, p.ImportPath, binary, "-o", out, importArgs, mainpkg)
 }
 
 func (goToolchain) cc(b *builder, p *Package, objdir, ofile, cfile string) error {
-	inc := filepath.Join(b.goroot, "pkg", fmt.Sprintf("%s_%s", b.goos, b.goarch))
+	inc := filepath.Join(goroot, "pkg", fmt.Sprintf("%s_%s", b.goos, b.goarch))
 	cfile = mkAbs(p.Dir, cfile)
-	binary := filepath.Join(b.goroot, "bin/go-tool/", b.arch+"c")
+	binary := filepath.Join(goroot, "bin/go-tool/", b.arch+"c")
 	return b.run(p.Dir, p.ImportPath, binary, "-FVw",
 		"-I", objdir, "-I", inc, "-o", ofile,
 		"-DGOOS_"+b.goos, "-DGOARCH_"+b.goarch, cfile)
@@ -1075,7 +1080,7 @@ func (tools gccgoToolchain) ld(b *builder, p *Package, out string, allactions []
 }
 
 func (gccgoToolchain) cc(b *builder, p *Package, objdir, ofile, cfile string) error {
-	inc := filepath.Join(b.goroot, "pkg", fmt.Sprintf("%s_%s", b.goos, b.goarch))
+	inc := filepath.Join(goroot, "pkg", fmt.Sprintf("%s_%s", b.goos, b.goarch))
 	cfile = mkAbs(p.Dir, cfile)
 	return b.run(p.Dir, p.ImportPath, "gcc", "-Wall", "-g",
 		"-I", objdir, "-I", inc, "-o", ofile,

src/cmd/go/clean.go

+// Copyright 2012 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 (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var cmdClean = &Command{
+	UsageLine: "clean [-i] [-r] [-n] [-x] [importpath...]",
+	Short:     "remove object files",
+	Long: `
+Clean removes object files from package source directories.
+The go command builds most objects in a temporary directory,
+so go clean is mainly concerned with object files left by other
+tools or by manual invocations of go build.
+
+Specifically, clean removes the following files from each of the
+source directories corresponding to the import paths:
+
+	_obj/            old object directory, left from Makefiles
+	_test/           old test directory, left from Makefiles
+	_testmain.go     old gotest file, left from Makefiles
+	test.out         old test log, left from Makefiles
+	build.out        old test log, left from Makefiles
+	*.[568ao]        object files, left from Makefiles
+
+	DIR(.exe)        from go build
+	DIR.test(.exe)   from go test -c
+	MAINFILE(.exe)   from go build MAINFILE.go
+
+In the list, DIR represents the final path element of the
+directory, and MAINFILE is the base name of any Go source
+file in the directory that is not included when building
+the package.
+
+The -i flag causes clean to remove the corresponding installed
+archive or binary (what 'go install' would create).
+
+The -n flag causes clean to print the remove commands it would execute,
+but not run them.
+
+The -r flag causes clean to be applied recursively to all the
+dependencies of the packages named by the import paths.
+
+The -x flag causes clean to print remove commands as it executes them.
+	`,
+}
+
+var cleanI bool // clean -i flag
+var cleanN bool // clean -n flag
+var cleanR bool // clean -r flag
+var cleanX bool // clean -x flag
+
+func init() {
+	// break init cycle
+	cmdClean.Run = runClean
+
+	cmdClean.Flag.BoolVar(&cleanI, "i", false, "")
+	cmdClean.Flag.BoolVar(&cleanN, "n", false, "")
+	cmdClean.Flag.BoolVar(&cleanR, "r", false, "")
+	cmdClean.Flag.BoolVar(&cleanX, "x", false, "")
+}
+
+func runClean(cmd *Command, args []string) {
+	for _, pkg := range packagesAndErrors(args) {
+		clean(pkg)
+	}
+}
+
+var cleaned = map[*Package]bool{}
+
+// TODO: These are dregs left by Makefile-based builds.
+// Eventually, can stop deleting these.
+var cleanDir = map[string]bool{
+	"_test": true,
+	"_obj":  true,
+}
+
+var cleanFile = map[string]bool{
+	"_testmain.go": true,
+	"test.out":     true,
+	"build.out":    true,
+	"a.out":        true,
+}
+
+var cleanExt = map[string]bool{
+	".5": true,
+	".6": true,
+	".8": true,
+	".a": true,
+	".o": true,
+}
+
+func clean(p *Package) {
+	if cleaned[p] {
+		return
+	}
+	if p.Dir == "" {
+		errorf("can't load package: %v", p.Error)
+		return
+	}
+	dirs, err := ioutil.ReadDir(p.Dir)
+	if err != nil {
+		errorf("%v", err)
+		return
+	}
+
+	var b builder
+
+	packageFile := map[string]bool{}
+	if p.Name != "main" {
+		// Record which files are not in package main.
+		// The others are.
+		keep := func(list []string) {
+			for _, f := range list {
+				packageFile[f] = true
+			}
+		}
+		keep(p.GoFiles)
+		keep(p.CgoFiles)
+		keep(p.TestGoFiles)
+		keep(p.XTestGoFiles)
+	}
+
+	_, elem := filepath.Split(p.Dir)
+	allRemove := []string{
+		elem,
+		elem + ".exe",
+		elem + ".test",
+		elem + ".test.exe",
+	}
+	for _, dir := range dirs {
+		name := dir.Name()
+		if packageFile[name] {
+			continue
+		}
+		if !dir.IsDir() && strings.HasSuffix(name, ".go") {
+			base := name[:len(name)-len(".go")]
+			allRemove = append(allRemove, base, base+".exe")
+		}
+	}
+	if cleanN || cleanX {
+		b.showcmd(p.Dir, "rm %s", strings.Join(allRemove, " "))
+	}
+
+	toRemove := map[string]bool{}
+	for _, name := range allRemove {
+		toRemove[name] = true
+	}
+	for _, dir := range dirs {
+		name := dir.Name()
+		if dir.IsDir() {
+			// TODO: Remove once Makefiles are forgotten.
+			if cleanDir[name] {
+				if cleanN || cleanX {
+					b.showcmd(p.Dir, "rm -r %s", name)
+					if cleanN {
+						continue
+					}
+				}
+				os.RemoveAll(filepath.Join(p.Dir, name))
+			}
+			continue
+		}
+
+		if cleanN {
+			continue
+		}
+
+		if cleanFile[name] || cleanExt[filepath.Ext(name)] || toRemove[name] {
+			os.Remove(filepath.Join(p.Dir, name))
+		}
+	}
+
+	if cleanI && p.target != "" {
+		if cleanN || cleanX {
+			b.showcmd("", "rm %s", p.target)
+		}
+		if !cleanN {
+			os.Remove(p.target)
+		}
+	}
+
+	if cleanR {
+		for _, p1 := range p.imports {
+			clean(p1)
+		}
+	}
+}

src/cmd/go/doc.go

@@ -10,6 +10,7 @@ Usage: go command [arguments]
 The commands are:
 
     build       compile packages and dependencies
+    clean       remove object files
     doc         run godoc on package sources
     fix         run gofix on packages
     fmt         run gofmt on package sources
@@ -18,6 +19,7 @@ The commands are:
     list        list packages
     run         compile and run Go program
     test        test packages
+    tool        run specified go tool
     version     print Go version
     vet         run govet on packages
 
@@ -67,6 +69,48 @@ For more about import paths, see 'go help importpath'.
 See also: go install, go get, go clean.
 
 
+Remove object files
+
+Usage:
+
+	go clean [-i] [-r] [-n] [-x] [importpath...]
+
+Clean removes object files from package source directories.
+The go command builds most objects in a temporary directory,
+so go clean is mainly concerned with object files left by other
+tools or by manual invocations of go build.
+
+Specifically, clean removes the following files from each of the
+source directories corresponding to the import paths:
+
+	_obj/            old object directory, left from Makefiles
+	_test/           old test directory, left from Makefiles
+	_testmain.go     old gotest file, left from Makefiles
+	test.out         old test log, left from Makefiles
+	build.out        old test log, left from Makefiles
+	*.[568ao]        object files, left from Makefiles
+
+	DIR(.exe)        from go build
+	DIR.test(.exe)   from go test -c
+	MAINFILE(.exe)   from go build MAINFILE.go
+
+In the list, DIR represents the final path element of the
+directory, and MAINFILE is the base name of any Go source
+file in the directory that is not included when building
+the package.
+
+The -i flag causes clean to remove the corresponding installed
+archive or binary (what 'go install' would create).
+
+The -n flag causes clean to print the remove commands it would execute,
+but not run them.
+
+The -r flag causes clean to be applied recursively to all the
+dependencies of the packages named by the import paths.
+
+The -x flag causes clean to print remove commands as it executes them.
+
+
 Run godoc on package sources
 
 Usage:
@@ -90,12 +134,12 @@ Usage:
 
 	go fix [importpath...]
 
-Fix runs the gofix command on the packages named by the import paths.
+Fix runs the Go fix command on the packages named by the import paths.
 
-For more about gofix, see 'godoc gofix'.
+For more about fix, see 'godoc fix'.
 For more about import paths, see 'go help importpath'.
 
-To run gofix with specific options, run gofix itself.
+To run fix with specific options, run 'go tool fix'.
 
 See also: go fmt, go vet.
 
@@ -252,7 +296,7 @@ Test packages
 
 Usage:
 
-	go test [-c] [-file a.go -file b.go ...] [-p n] [-x] [importpath...] [flags for test binary]
+	go test [-c] [-file a.go -file b.go ...] [-i] [-p n] [-x] [importpath...] [flags for test binary]
 
 'Go test' automates testing the packages named by the import paths.
 It prints a summary of the test results in the format:
@@ -285,6 +329,18 @@ See 'go help importpath' for more about import paths.
 See also: go build, go vet.
 
 
+Run specified go tool
+
+Usage:
+
+	go tool command [args...]
+
+Tool runs the go tool command identified by the arguments.
+With no arguments it prints the list of known tools.
+
+For more about each tool command, see 'go tool command -h'.
+
+
 Print Go version
 
 Usage:
@@ -300,12 +356,12 @@ Usage:
 
 	go vet [importpath...]
 
-Vet runs the govet command on the packages named by the import paths.
+Vet runs the Go vet command on the packages named by the import paths.
 
-For more about govet, see 'godoc govet'.
+For more about vet, see 'godoc vet'.
 For more about import paths, see 'go help importpath'.
 
-To run govet with specific options, run govet itself.
+To run govet with specific options, run 'go tool vet'.
 
 See also: go fmt, go fix.
 
@@ -487,19 +543,23 @@ and flags that apply to the resulting test binary.
 
 The flags handled by 'go test' are:
 
-	-c  Compile the test binary to test.out but do not run it.
+	-c  Compile the test binary to pkg.test but do not run it.
 
 	-file a.go
 	    Use only the tests in the source file a.go.
 	    Multiple -file flags may be provided.
 
+	-i
+	    Install packages that are dependencies of the test.
+
 	-p n
 	    Compile and test up to n packages in parallel.
 	    The default value is the number of CPUs available.
 
 	-x  Print each subcommand go test executes.
 
-The resulting test binary, called test.out, has its own flags:
+The resulting test binary, called pkg.test, where pkg is the name of the
+directory containing the package sources, has its own flags:
 
 	-test.v
 	    Verbose output: log all tests as they are run.
@@ -557,7 +617,7 @@ here are passed through unaltered.  For instance, the command
 
 will compile the test binary using x_test.go and then run it as
 
-	test.out -test.v -test.cpuprofile=prof.out -dir=testdata -update
+	pkg.test -test.v -test.cpuprofile=prof.out -dir=testdata -update
 
 
 Description of testing functions

src/cmd/go/main.go

@@ -67,6 +67,7 @@ func (c *Command) Usage() {
 // The order here is the order in which they are printed by 'go help'.
 var commands = []*Command{
 	cmdBuild,
+	cmdClean,
 	cmdDoc,
 	cmdFix,
 	cmdFmt,

src/cmd/go/pkg.go

@@ -8,6 +8,7 @@ import (
 	"go/build"
 	"os"
 	"path/filepath"
+	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -22,6 +23,7 @@ type Package struct {
 	Name       string        `json:",omitempty"` // package name
 	Doc        string        `json:",omitempty"` // package documentation string
 	Dir        string        `json:",omitempty"` // directory containing package sources
+	Target     string        `json:",omitempty"` // install path
 	Version    string        `json:",omitempty"` // version of installed package (TODO)
 	Standard   bool          `json:",omitempty"` // is this package part of the standard Go library?
 	Stale      bool          `json:",omitempty"` // would 'go install' do anything for this package?
@@ -273,6 +275,10 @@ func scanPackage(ctxt *build.Context, t *build.Tree, arg, importPath, dir string
 		if t.Goroot && isGoTool[p.ImportPath] {
 			p.target = filepath.Join(t.Path, "bin/go-tool", elem)
 		} else {
+			if ctxt.GOOS != runtime.GOOS || ctxt.GOARCH != runtime.GOARCH {
+				// Install cross-compiled binaries to subdirectories of bin.
+				elem = ctxt.GOOS + "_" + ctxt.GOARCH + "/" + elem
+			}
 			p.target = filepath.Join(t.BinDir(), elem)
 		}
 		if ctxt.GOOS == "windows" {
@@ -404,6 +410,8 @@ Stale:
 		p.target = ""
 	}
 
+	p.Target = p.target
+
 	return p
 }
 

src/cmd/go/test.go

@@ -13,6 +13,7 @@ import (
 	"go/token"
 	"os"
 	"os/exec"
+	"path"
 	"path/filepath"
 	"strings"
 	"text/template"
@@ -28,7 +29,7 @@ func init() {
 
 var cmdTest = &Command{
 	CustomFlags: true,
-	UsageLine:   "test [-c] [-file a.go -file b.go ...] [-p n] [-x] [importpath...] [flags for test binary]",
+	UsageLine:   "test [-c] [-file a.go -file b.go ...] [-i] [-p n] [-x] [importpath...] [flags for test binary]",
 	Short:       "test packages",
 	Long: `
 'Go test' automates testing the packages named by the import paths.
@@ -72,19 +73,23 @@ and flags that apply to the resulting test binary.
 
 The flags handled by 'go test' are:
 
-	-c  Compile the test binary to test.out but do not run it.
+	-c  Compile the test binary to pkg.test but do not run it.
 
 	-file a.go
 	    Use only the tests in the source file a.go.
 	    Multiple -file flags may be provided.
 
+	-i
+	    Install packages that are dependencies of the test.
+
 	-p n
 	    Compile and test up to n packages in parallel.
 	    The default value is the number of CPUs available.
 
 	-x  Print each subcommand go test executes.
 
-The resulting test binary, called test.out, has its own flags:
+The resulting test binary, called pkg.test, where pkg is the name of the
+directory containing the package sources, has its own flags:
 
 	-test.v
 	    Verbose output: log all tests as they are run.
@@ -142,7 +147,7 @@ here are passed through unaltered.  For instance, the command
 
 will compile the test binary using x_test.go and then run it as
 
-	test.out -test.v -test.cpuprofile=prof.out -dir=testdata -update
+	pkg.test -test.v -test.cpuprofile=prof.out -dir=testdata -update
 	`,
 }
 
@@ -296,7 +301,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 	// Build Package structs describing:
 	//	ptest - package + test files
 	//	pxtest - package of external test files
-	//	pmain - test.out binary
+	//	pmain - pkg.test binary
 	var ptest, pxtest, pmain *Package
 
 	// go/build does not distinguish the dependencies used
@@ -315,6 +320,11 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 	}
 	stk.pop()
 
+	// Use last element of import path, not package name.
+	// They differ when package name is "main".
+	_, elem := path.Split(p.ImportPath)
+	testBinary := elem + ".test"
+
 	// The ptest package needs to be importable under the
 	// same import path that p has, but we cannot put it in
 	// the usual place in the temporary tree, because then
@@ -383,7 +393,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 		a.target = a.objpkg
 	}
 
-	// Action for building test.out.
+	// Action for building pkg.test.
 	pmain = &Package{
 		Name:    "main",
 		Dir:     testDir,
@@ -412,7 +422,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 	a := b.action(modeBuild, modeBuild, pmain)
 	a.objdir = testDir + string(filepath.Separator)
 	a.objpkg = filepath.Join(testDir, "main.a")
-	a.target = filepath.Join(testDir, "test.out") + b.exe
+	a.target = filepath.Join(testDir, testBinary) + b.exe
 	pmainAction := a
 
 	if testC {
@@ -421,7 +431,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 			f:      (*builder).install,
 			deps:   []*action{pmainAction},
 			p:      pmain,
-			target: "test.out" + b.exe,
+			target: testBinary + b.exe,
 		}
 		printAction = &action{p: p, deps: []*action{runAction}} // nop
 	} else {

src/cmd/go/testflag.go

@@ -79,7 +79,7 @@ var testFlagDefn = []*testFlagSpec{
 // to have "test" before them, and reading the command line for the 6.out.
 // Unfortunately for us, we need to do our own flag processing because go test
 // grabs some flags but otherwise its command line is just a holding place for
-// test.out's arguments.
+// pkg.test's arguments.
 // We allow known flags both before and after the package name list,
 // to allow both
 //	go test fmt -custom-flag-for-fmt-test