go: implement doc, fmt, fix, list, vet

This CL is concerned with the basic Package structure
and applies it to the (trivial) implementations of the
doc, fmt, fix, list, and vet commands.

The command as a whole is still very much a work in progress.
In particular, work making the error messages look nice
is deferred to a future CL.

R=golang-dev, adg, dsymonds, r
CC=golang-dev
https://golang.org/cl/5482048

src/cmd/go/Makefile

@@ -14,6 +14,7 @@ GOFILES=\
 	help.go\
 	list.go\
 	main.go\
+	pkg.go\
 	test.go\
 	version.go\
 	vet.go\

src/cmd/go/doc.go

@@ -31,3 +31,5 @@ Additional help topics:
 Use "go help [topic]" for more information about that topic.
 */
 package documentation
+
+// NOTE: cmdDoc is in fmt.go.

src/cmd/go/fix.go

@@ -21,7 +21,10 @@ See also: go fmt, go vet.
 }
 
 func runFix(cmd *Command, args []string) {
-	args = importPaths(args)
-	_ = args
-	panic("fix not implemented")
+	for _, pkg := range packages(args) {
+		// Use pkg.gofiles instead of pkg.Dir so that
+		// the command only applies to this package,
+		// not to packages in subdirectories.
+		run(append([]string{"gofix"}, pkg.gofiles...)...)
+	}
 }

src/cmd/go/fmt.go

@@ -7,21 +7,48 @@ package main
 var cmdFmt = &Command{
 	Run:       runFmt,
 	UsageLine: "fmt [importpath...]",
-	Short:     "run gofmt -w on packages",
+	Short:     "run gofmt on package sources",
 	Long: `
-Fmt runs the command 'gofmt -w' on the packages named by the import paths.
+Fmt runs the command 'gofmt -l -w' on the packages named
+by the import paths.  It prints the names of the files that are modified.
 
 For more about gofmt, see 'godoc gofmt'.
 For more about import paths, see 'go help importpath'.
 
 To run gofmt with specific options, run gofmt itself.
 
-See also: go fix, go vet.
+See also: go doc, go fix, go vet.
 	`,
 }
 
 func runFmt(cmd *Command, args []string) {
-	args = importPaths(args)
-	_ = args
-	panic("fmt not implemented")
+	for _, pkg := range packages(args) {
+		// Use pkg.gofiles instead of pkg.Dir so that
+		// the command only applies to this package,
+		// not to packages in subdirectories.
+		run(append([]string{"gofmt", "-l", "-w"}, pkg.gofiles...)...)
+	}
+}
+
+var cmdDoc = &Command{
+	Run:       runDoc,
+	UsageLine: "doc [importpath...]",
+	Short:     "run godoc on package sources",
+	Long: `
+Doc runs the godoc command on the packages named by the
+import paths.
+
+For more about godoc, see 'godoc godoc'.
+For more about import paths, see 'go help importpath'.
+
+To run gofmt with specific options, run gofmt itself.
+
+See also: go fix, go fmt, go vet.
+	`,
+}
+
+func runDoc(cmd *Command, args []string) {
+	for _, pkg := range packages(args) {
+		run("godoc", pkg.Dir)
+	}
 }

src/cmd/go/list.go

@@ -4,8 +4,13 @@
 
 package main
 
+import (
+	"encoding/json"
+	"os"
+	"text/template"
+)
+
 var cmdList = &Command{
-	Run:       runList,
 	UsageLine: "list [-f format] [-json] [importpath...]",
 	Short:     "list packages",
 	Long: `
@@ -19,31 +24,59 @@ The default output shows the package name and file system location:
 
 The -f flag specifies an alternate format for the list,
 using the syntax of package template.  The default output
-is equivalent to -f '{{.Name}} {{.Dir}}'  The struct
+is equivalent to -f '{{.Name}} {{.Dir}}'.  The struct
 being passed to the template is:
 
     type Package struct {
-        Name string         // package name
-        Doc string          // package documentation string
-        GoFiles []string    // names of Go source files in package
-        ImportPath string   // import path denoting package
-        Imports []string    // import paths used by this package
-        Deps []string       // all (recursively) imported dependencies
-        Dir string          // directory containing package sources
-        Version string      // version of installed package
+        Name       string // package name
+        Doc        string // package documentation string
+        ImportPath string // import path of package in dir
+        Dir        string // directory containing package sources
+        Version    string // version of installed package (TODO)
+
+        // Source files
+        GoFiles  []string // .go source files (excluding CgoFiles)
+        CFiles   []string // .c source files
+        SFiles   []string // .s source files
+        CgoFiles []string // .go sources files that import "C"
+
+        // Dependency information
+        Imports []string // import paths used by this package
+        Deps    []string // all (recursively) imported dependencies
     }
 
-The -json flag causes the package data to be printed in JSON format.
+The -json flag causes the package data to be printed in JSON format
+instead of using the template format.
 
 For more about import paths, see 'go help importpath'.
 	`,
 }
 
+func init() {
+	cmdList.Run = runList // break init cycle
+}
+
 var listFmt = cmdList.Flag.String("f", "{{.Name}} {{.Dir}}", "")
 var listJson = cmdList.Flag.Bool("json", false, "")
 
 func runList(cmd *Command, args []string) {
-	args = importPaths(args)
-	_ = args
-	panic("list not implemented")
+	var do func(*Package)
+	if *listJson {
+		enc := json.NewEncoder(os.Stdout)
+		do = func(p *Package) { enc.Encode(p) }
+	} else {
+		tmpl, err := template.New("main").Parse(*listFmt + "\n")
+		if err != nil {
+			fatalf("%s", err)
+		}
+		do = func(p *Package) {
+			if err := tmpl.Execute(os.Stdout, p); err != nil {
+				fatalf("%s", err)
+			}
+		}
+	}
+
+	for _, pkg := range packages(args) {
+		do(pkg)
+	}
 }

src/cmd/go/main.go

@@ -8,7 +8,9 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"log"
 	"os"
+	"os/exec"
 	"strings"
 	"text/template"
 )
@@ -55,6 +57,7 @@ func (c *Command) Usage() {
 var commands = []*Command{
 	cmdBuild,
 	cmdClean,
+	cmdDoc,
 	cmdFix,
 	cmdFmt,
 	cmdGet,
@@ -69,9 +72,12 @@ var commands = []*Command{
 	helpRemote,
 }
 
+var exitStatus = 0
+
 func main() {
 	flag.Usage = usage
 	flag.Parse()
+	log.SetFlags(0)
 
 	args := flag.Args()
 	if len(args) < 1 {
@@ -89,6 +95,7 @@ func main() {
 			cmd.Flag.Parse(args[1:])
 			args = cmd.Flag.Args()
 			cmd.Run(cmd, args)
+			os.Exit(exitStatus)
 			return
 		}
 	}
@@ -172,3 +179,28 @@ func importPaths(args []string) []string {
 	}
 	return args
 }
+
+func fatalf(format string, args ...interface{}) {
+	log.Printf(format, args...)
+	os.Exit(1)
+}
+
+func errorf(format string, args ...interface{}) {
+	log.Printf(format, args...)
+	exitStatus = 1
+}
+
+func exitIfErrors() {
+	if exitStatus != 0 {
+		os.Exit(exitStatus)
+	}
+}
+
+func run(cmdline ...string) {
+	cmd := exec.Command(cmdline[0], cmdline[1:]...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		errorf("%v", err)
+	}
+}

src/cmd/go/pkg.go

@@ -0,0 +1,163 @@
+// 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/build"
+	"go/doc"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// A Package describes a single package found in a directory.
+type Package struct {
+	// Note: These fields are part of the go command's public API.
+	// See list.go.  It is okay to add fields, but not to change or
+	// remove existing ones.  Keep in sync with list.go
+	Name       string // package name
+	Doc        string // package documentation string
+	ImportPath string // import path of package in dir
+	Dir        string // directory containing package sources
+	Version    string // version of installed package (TODO)
+	Standard   bool   // is this package part of the standard Go library?
+
+	// Source files
+	GoFiles  []string // .go source files (excluding CgoFiles)
+	CFiles   []string // .c source files
+	SFiles   []string // .s source files
+	CgoFiles []string // .go sources files that import "C"
+
+	// Dependency information
+	Imports []string // import paths used by this package
+	Deps    []string // all (recursively) imported dependencies
+
+	// Unexported fields are not part of the public API.
+	t       *build.Tree
+	info    *build.DirInfo
+	imports []*Package
+	gofiles []string // GoFiles+CgoFiles
+}
+
+// packageCache is a lookup cache for loadPackage,
+// so that if we look up a package multiple times
+// we return the same pointer each time.
+var packageCache = map[string]*Package{}
+
+// loadPackage scans directory named by arg,
+// which is either an import path or a file system path
+// (if the latter, must be rooted or begin with . or ..),
+// and returns a *Package describing the package
+// found in that directory.
+func loadPackage(arg string) (*Package, error) {
+	// Check package cache.
+	if p := packageCache[arg]; p != nil {
+		// We use p.imports==nil to detect a package that
+		// is in the midst of its own loadPackage call
+		// (all the recursion below happens before p.imports gets set).
+		if p.imports == nil {
+			return nil, fmt.Errorf("import loop at %s", arg)
+		}
+		return p, nil
+	}
+
+	// Find basic information about package path.
+	t, importPath, err := build.FindTree(arg)
+	if err != nil {
+		return nil, err
+	}
+	dir := filepath.Join(t.SrcDir(), importPath)
+
+	// Maybe we know the package by its directory.
+	if p := packageCache[dir]; p != nil {
+		if p.imports == nil {
+			return nil, fmt.Errorf("import loop at %s", arg)
+		}
+		return p, nil
+	}
+
+	// Read the files in the directory to learn the structure
+	// of the package.
+	info, err := build.ScanDir(dir)
+	if err != nil {
+		return nil, err
+	}
+
+	p := &Package{
+		Name:       info.Package,
+		Doc:        doc.CommentText(info.PackageComment),
+		ImportPath: importPath,
+		Dir:        dir,
+		Imports:    info.Imports,
+		GoFiles:    info.GoFiles,
+		CFiles:     info.CFiles,
+		SFiles:     info.SFiles,
+		CgoFiles:   info.CgoFiles,
+		Standard:   t.Goroot && !strings.Contains(importPath, "."),
+	}
+
+	// Build list of full paths to all Go files in the package,
+	// for use by commands like go fmt.
+	for _, f := range info.GoFiles {
+		p.gofiles = append(p.gofiles, filepath.Join(dir, f))
+	}
+	for _, f := range info.CgoFiles {
+		p.gofiles = append(p.gofiles, filepath.Join(dir, f))
+	}
+	sort.Strings(p.gofiles)
+
+	// Record package under both import path and full directory name.
+	packageCache[dir] = p
+	packageCache[importPath] = p
+
+	// Build list of imported packages and full dependency list.
+	imports := make([]*Package, 0, len(p.Imports))
+	deps := make(map[string]bool)
+	for _, path := range p.Imports {
+		deps[path] = true
+		if path == "C" {
+			continue
+		}
+		p1, err := loadPackage(path)
+		if err != nil {
+			delete(packageCache, arg)
+			delete(packageCache, importPath)
+			// Add extra error detail to show full import chain.
+			// Always useful, but especially useful in import loops.
+			return nil, fmt.Errorf("%s: import %s\n\t%v", arg, path, err)
+		}
+		imports = append(imports, p1)
+
+		for _, dep := range p1.Deps {
+			deps[dep] = true
+		}
+	}
+	p.imports = imports
+
+	p.Deps = make([]string, 0, len(deps))
+	for dep := range deps {
+		p.Deps = append(p.Deps, dep)
+	}
+	sort.Strings(p.Deps)
+
+	return p, nil
+}
+
+// packages returns the packages named by the
+// command line arguments 'args'.
+func packages(args []string) []*Package {
+	args = importPaths(args)
+	var pkgs []*Package
+	for _, arg := range args {
+		pkg, err := loadPackage(arg)
+		if err != nil {
+			errorf("%s", err)
+			continue
+		}
+		pkgs = append(pkgs, pkg)
+	}
+	return pkgs
+}

src/cmd/go/vet.go

@@ -21,7 +21,10 @@ See also: go fmt, go fix.
 }
 
 func runVet(cmd *Command, args []string) {
-	args = importPaths(args)
-	_ = args
-	panic("vet not implemented")
+	for _, pkg := range packages(args) {
+		// Use pkg.gofiles instead of pkg.Dir so that
+		// the command only applies to this package,
+		// not to packages in subdirectories.
+		run(append([]string{"govet"}, pkg.gofiles...)...)
+	}
 }