goinstall: use go/make package to scan and build packages

R=rsc, n13m3y3r, kevlar
CC=golang-dev
https://golang.org/cl/4515180

4 files changed, 169 insertions, 51 deletions

diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index c4be1da497..9bed810267 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -208,6 +208,7 @@ NOTEST+=\
 	../cmd/cgo\
 	../cmd/ebnflint\
 	../cmd/godoc\
+	../cmd/goinstall\
 	../cmd/gotest\
 	../cmd/govet\
 	../cmd/goyacc\
diff --git a/src/pkg/go/build/build.go b/src/pkg/go/build/build.go
index 3cb8efe479..8dd4c4ee44 100644
--- a/src/pkg/go/build/build.go
+++ b/src/pkg/go/build/build.go
@@ -15,8 +15,14 @@ import (
 	"strings"
 )
 
-func (d *DirInfo) Build(targ string) ([]*Cmd, os.Error) {
-	b := &build{obj: "_obj/"}
+// Build produces a build Script for the given package.
+func Build(tree *Tree, pkg string, info *DirInfo) (*Script, os.Error) {
+	s := &Script{}
+	b := &build{
+		script: s,
+		path:   filepath.Join(tree.SrcDir(), pkg),
+	}
+	b.obj = b.abs("_obj") + "/"
 
 	goarch := runtime.GOARCH
 	if g := os.Getenv("GOARCH"); g != "" {
@@ -28,17 +34,25 @@ func (d *DirInfo) Build(targ string) ([]*Cmd, os.Error) {
 		return nil, err
 	}
 
-	var gofiles = d.GoFiles // .go files to be built with gc
-	var ofiles []string     // *.GOARCH files to be linked or packed
+	// .go files to be built with gc
+	gofiles := b.abss(info.GoFiles...)
+	s.addInput(gofiles...)
+
+	var ofiles []string // object files to be linked or packed
 
 	// make build directory
 	b.mkdir(b.obj)
+	s.addIntermediate(b.obj)
 
 	// cgo
-	if len(d.CgoFiles) > 0 {
-		outGo, outObj := b.cgo(d.CgoFiles)
+	if len(info.CgoFiles) > 0 {
+		cgoFiles := b.abss(info.CgoFiles...)
+		s.addInput(cgoFiles...)
+		outGo, outObj := b.cgo(cgoFiles)
 		gofiles = append(gofiles, outGo...)
 		ofiles = append(ofiles, outObj...)
+		s.addIntermediate(outGo...)
+		s.addIntermediate(outObj...)
 	}
 
 	// compile
@@ -46,31 +60,130 @@ func (d *DirInfo) Build(targ string) ([]*Cmd, os.Error) {
 		ofile := b.obj + "_go_." + b.arch
 		b.gc(ofile, gofiles...)
 		ofiles = append(ofiles, ofile)
+		s.addIntermediate(ofile)
 	}
 
 	// assemble
-	for _, sfile := range d.SFiles {
+	for _, sfile := range info.SFiles {
 		ofile := b.obj + sfile[:len(sfile)-1] + b.arch
+		sfile = b.abs(sfile)
+		s.addInput(sfile)
 		b.asm(ofile, sfile)
 		ofiles = append(ofiles, ofile)
+		s.addIntermediate(sfile, ofile)
 	}
 
 	if len(ofiles) == 0 {
 		return nil, os.NewError("make: no object files to build")
 	}
 
-	if d.IsCommand() {
+	// choose target file
+	var targ string
+	if info.IsCommand() {
+		// use the last part of the import path as binary name
+		_, bin := filepath.Split(pkg)
+		targ = filepath.Join(tree.BinDir(), bin)
+	} else {
+		targ = filepath.Join(tree.PkgDir(), pkg+".a")
+	}
+
+	// make target directory
+	targDir, _ := filepath.Split(targ)
+	b.mkdir(targDir)
+
+	// link binary or pack object
+	if info.IsCommand() {
 		b.ld(targ, ofiles...)
 	} else {
 		b.gopack(targ, ofiles...)
 	}
+	s.Output = append(s.Output, targ)
+
+	return b.script, nil
+}
+
+// A Script describes the build process for a Go package.
+// The Input, Intermediate, and Output fields are lists of absolute paths.
+type Script struct {
+	Cmd          []*Cmd
+	Input        []string
+	Intermediate []string
+	Output       []string
+}
+
+func (s *Script) addInput(file ...string) {
+	s.Input = append(s.Input, file...)
+}
+
+func (s *Script) addIntermediate(file ...string) {
+	s.Intermediate = append(s.Intermediate, file...)
+}
+
+// Run runs the Script's Cmds in order.
+func (s *Script) Run() os.Error {
+	for _, c := range s.Cmd {
+		if err := c.Run(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
 
-	return b.cmds, nil
+// Stale returns true if the build's inputs are newer than its outputs.
+func (s *Script) Stale() bool {
+	var latest int64
+	// get latest mtime of outputs
+	for _, file := range s.Output {
+		fi, err := os.Stat(file)
+		if err != nil {
+			// any error reading output files means stale
+			return true
+		}
+		if m := fi.Mtime_ns; m > latest {
+			latest = m
+		}
+	}
+	for _, file := range s.Input {
+		fi, err := os.Stat(file)
+		if err != nil || fi.Mtime_ns > latest {
+			// any error reading input files means stale
+			// (attempt to rebuild to figure out why)
+			return true
+		}
+	}
+	return false
 }
 
+// Clean removes the Script's Intermediate files.
+// It tries to remove every file and returns the first error it encounters.
+func (s *Script) Clean() (err os.Error) {
+	for i := len(s.Intermediate) - 1; i >= 0; i-- {
+		if e := os.Remove(s.Intermediate[i]); err == nil {
+			err = e
+		}
+	}
+	return
+}
+
+// Clean removes the Script's Intermediate and Output files.
+// It tries to remove every file and returns the first error it encounters.
+func (s *Script) Nuke() (err os.Error) {
+	for i := len(s.Output) - 1; i >= 0; i-- {
+		if e := os.Remove(s.Output[i]); err == nil {
+			err = e
+		}
+	}
+	if e := s.Clean(); err == nil {
+		err = e
+	}
+	return
+}
+
+// A Cmd describes an individual build command.
 type Cmd struct {
 	Args   []string // command-line
 	Stdout string   // write standard output to this file, "" is passthrough
+	Dir    string   // working directory
 	Input  []string // file paths (dependencies)
 	Output []string // file paths
 }
@@ -79,14 +192,15 @@ func (c *Cmd) String() string {
 	return strings.Join(c.Args, " ")
 }
 
-func (c *Cmd) Run(dir string) os.Error {
+// Run executes the Cmd.
+func (c *Cmd) Run() os.Error {
 	out := new(bytes.Buffer)
 	cmd := exec.Command(c.Args[0], c.Args[1:]...)
-	cmd.Dir = dir
+	cmd.Dir = c.Dir
 	cmd.Stdout = out
 	cmd.Stderr = out
 	if c.Stdout != "" {
-		f, err := os.Create(filepath.Join(dir, c.Stdout))
+		f, err := os.Create(c.Stdout)
 		if err != nil {
 			return err
 		}
@@ -99,15 +213,6 @@ func (c *Cmd) Run(dir string) os.Error {
 	return nil
 }
 
-func (c *Cmd) Clean(dir string) (err os.Error) {
-	for _, fn := range c.Output {
-		if e := os.RemoveAll(fn); err == nil {
-			err = e
-		}
-	}
-	return
-}
-
 // ArchChar returns the architecture character for the given goarch.
 // For example, ArchChar("amd64") returns "6".
 func ArchChar(goarch string) (string, os.Error) {
@@ -123,13 +228,29 @@ func ArchChar(goarch string) (string, os.Error) {
 }
 
 type build struct {
-	cmds []*Cmd
-	obj  string
-	arch string
+	script *Script
+	path   string
+	obj    string
+	arch   string
+}
+
+func (b *build) abs(file string) string {
+	if filepath.IsAbs(file) {
+		return file
+	}
+	return filepath.Join(b.path, file)
+}
+
+func (b *build) abss(file ...string) []string {
+	s := make([]string, len(file))
+	for i, f := range file {
+		s[i] = b.abs(f)
+	}
+	return s
 }
 
 func (b *build) add(c Cmd) {
-	b.cmds = append(b.cmds, &c)
+	b.script.Cmd = append(b.script.Cmd, &c)
 }
 
 func (b *build) mkdir(name string) {
@@ -222,6 +343,7 @@ func (b *build) cgo(cgofiles []string) (outGo, outObj []string) {
 	gofiles := []string{b.obj + "_cgo_gotypes.go"}
 	cfiles := []string{b.obj + "_cgo_main.c", b.obj + "_cgo_export.c"}
 	for _, fn := range cgofiles {
+		fn = filepath.Base(fn)
 		f := b.obj + fn[:len(fn)-2]
 		gofiles = append(gofiles, f+"cgo1.go")
 		cfiles = append(cfiles, f+"cgo2.c")
diff --git a/src/pkg/go/build/build_test.go b/src/pkg/go/build/build_test.go
index c543eddbda..c760c5cc6f 100644
--- a/src/pkg/go/build/build_test.go
+++ b/src/pkg/go/build/build_test.go
@@ -5,50 +5,46 @@
 package build
 
 import (
-	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
 )
 
-var buildDirs = []string{
-	"pkg/path",
-	"cmd/gofix",
-	"pkg/big",
-	"pkg/go/build/cgotest",
+// TODO(adg): test building binaries
+
+var buildPkgs = []string{
+	"path",
+	"big",
+	"go/build/cgotest",
 }
 
 func TestBuild(t *testing.T) {
-	out, err := filepath.Abs("_test/out")
-	if err != nil {
-		t.Fatal(err)
-	}
-	for _, d := range buildDirs {
-		if runtime.GOARCH == "arm" && strings.Contains(d, "/cgo") {
+	for _, pkg := range buildPkgs {
+		if runtime.GOARCH == "arm" && strings.Contains(pkg, "/cgo") {
 			// no cgo for arm, yet.
 			continue
 		}
-		dir := filepath.Join(runtime.GOROOT(), "src", d)
-		testBuild(t, dir, out)
+		tree := Path[0] // Goroot
+		testBuild(t, tree, pkg)
 	}
 }
 
-func testBuild(t *testing.T, dir, targ string) {
-	d, err := ScanDir(dir, true)
+func testBuild(t *testing.T, tree *Tree, pkg string) {
+	dir := filepath.Join(tree.SrcDir(), pkg)
+	info, err := ScanDir(dir, true)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-	defer os.Remove(targ)
-	cmds, err := d.Build(targ)
+	s, err := Build(tree, pkg, info)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-	for _, c := range cmds {
+	for _, c := range s.Cmd {
 		t.Log("Run:", c)
-		err = c.Run(dir)
+		err = c.Run()
 		if err != nil {
 			t.Error(c, err)
 			return
diff --git a/src/pkg/go/build/dir.go b/src/pkg/go/build/dir.go
index 77e80bff0b..dda33bb6b6 100644
--- a/src/pkg/go/build/dir.go
+++ b/src/pkg/go/build/dir.go
@@ -50,7 +50,6 @@ func ScanDir(dir string, allowMain bool) (info *DirInfo, err os.Error) {
 
 	var di DirInfo
 	imported := make(map[string]bool)
-	pkgName := ""
 	fset := token.NewFileSet()
 	for i := range dirs {
 		d := &dirs[i]
@@ -89,14 +88,14 @@ func ScanDir(dir string, allowMain bool) (info *DirInfo, err os.Error) {
 		if s == "documentation" {
 			continue
 		}
-		if pkgName == "" {
-			pkgName = s
-		} else if pkgName != s {
+		if di.PkgName == "" {
+			di.PkgName = s
+		} else if di.PkgName != s {
 			// Only if all files in the directory are in package main
-			// do we return pkgName=="main".
+			// do we return PkgName=="main".
 			// A mix of main and another package reverts
 			// to the original (allowMain=false) behaviour.
-			if s == "main" || pkgName == "main" {
+			if s == "main" || di.PkgName == "main" {
 				return ScanDir(dir, false)
 			}
 			return nil, os.ErrorString("multiple package names in " + dir)