Run globs during earlier bootstrap phases

Instead of sometimes re-running minibp/the primary builder during the
next phase, run bpglob earlier to check dependencies.

We've run into issues where the environment is slightly different
between bootstrapping phase and the main build phase. It's also a
problem because our primary builder (Soong) exports information used by
another tool (Kati) that runs in between the bootstrapping phases and
the main phase. When Soong would run in the main phase, it could get out
of sync, and would require the build to be run again.

To do this, add a "subninja" include a build-globs.ninja file to each
build.ninja file. The first time, this will be an empty file, but we'll
always run minibp / the primary builder anyway. When the builder runs,
in addition to writing a dependency file, write out the
build-globs.ninja file with the rules to run bpglob.

Since bpglob may need to be run very early, before it would normally be
built, build it with microfactory.

Change-Id: I89fcd849a8729e892f163d40060ab90b5d4dfa5d

blueprint_impl.bash

@@ -28,6 +28,8 @@ source "${BLUEPRINTDIR}/microfactory/microfactory.bash"
 
 BUILDDIR="${BUILDDIR}/.minibootstrap" build_go minibp github.com/google/blueprint/bootstrap/minibp
 
+BUILDDIR="${BUILDDIR}/.minibootstrap" build_go bpglob github.com/google/blueprint/bootstrap/bpglob
+
 # Build the bootstrap build.ninja
 "${NINJA}" -w dupbuild=err -f "${BUILDDIR}/.minibootstrap/build.ninja"
 

bootstrap.bash

@@ -107,6 +107,10 @@ echo "extraArgs = $EXTRA_ARGS" >> $BUILDDIR/.minibootstrap/build.ninja
 echo "builddir = $NINJA_BUILDDIR" >> $BUILDDIR/.minibootstrap/build.ninja
 echo "include $BLUEPRINTDIR/bootstrap/build.ninja" >> $BUILDDIR/.minibootstrap/build.ninja
 
+if [ ! -f "$BUILDDIR/.minibootstrap/build-globs.ninja" ]; then
+    touch "$BUILDDIR/.minibootstrap/build-globs.ninja"
+fi
+
 echo "BLUEPRINT_BOOTSTRAP_VERSION=2" > $BUILDDIR/.blueprint.bootstrap
 echo "SRCDIR=\"${SRCDIR}\"" >> $BUILDDIR/.blueprint.bootstrap
 echo "BLUEPRINTDIR=\"${BLUEPRINTDIR}\"" >> $BUILDDIR/.blueprint.bootstrap

bootstrap/bootstrap.go

@@ -17,6 +17,8 @@ package bootstrap
 import (
 	"fmt"
 	"go/build"
+	"io/ioutil"
+	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -118,14 +120,14 @@ var (
 
 	generateBuildNinja = pctx.StaticRule("build.ninja",
 		blueprint.RuleParams{
-			Command:     "$builder $extra -b $buildDir -n $ninjaBuildDir -d $out.d -o $out $in",
+			Command:     "$builder $extra -b $buildDir -n $ninjaBuildDir -d $out.d -globFile $globFile -o $out $in",
 			CommandDeps: []string{"$builder"},
 			Description: "$builder $out",
 			Deps:        blueprint.DepsGCC,
 			Depfile:     "$out.d",
 			Restat:      true,
 		},
-		"builder", "extra", "generator")
+		"builder", "extra", "generator", "globFile")
 
 	// Work around a Ninja issue.  See https://github.com/martine/ninja/pull/634
 	phony = pctx.StaticRule("phony",
@@ -668,32 +670,33 @@ func (s *singleton) GenerateBuildActions(ctx blueprint.SingletonContext) {
 	topLevelBlueprints := filepath.Join("$srcDir",
 		filepath.Base(s.config.topLevelBlueprintsFile))
 
-	mainNinjaFile := filepath.Join("$buildDir", "build.ninja")
-	primaryBuilderNinjaFile := filepath.Join(bootstrapDir, "build.ninja")
-
 	ctx.SetNinjaBuildDir(pctx, "${ninjaBuildDir}")
 
-	// Build the main build.ninja
-	ctx.Build(pctx, blueprint.BuildParams{
-		Rule:    generateBuildNinja,
-		Outputs: []string{mainNinjaFile},
-		Inputs:  []string{topLevelBlueprints},
-		Args: map[string]string{
-			"builder": primaryBuilderFile,
-			"extra":   primaryBuilderExtraFlags,
-		},
-	})
+	if s.config.stage == StagePrimary {
+		mainNinjaFile := filepath.Join("$buildDir", "build.ninja")
+		primaryBuilderNinjaGlobFile := filepath.Join(BuildDir, bootstrapSubDir, "build-globs.ninja")
 
-	// Add a way to rebuild the primary build.ninja so that globs works
-	ctx.Build(pctx, blueprint.BuildParams{
-		Rule:    generateBuildNinja,
-		Outputs: []string{primaryBuilderNinjaFile},
-		Inputs:  []string{topLevelBlueprints},
-		Args: map[string]string{
-			"builder": minibpFile,
-			"extra":   extraSharedFlagString,
-		},
-	})
+		if _, err := os.Stat(primaryBuilderNinjaGlobFile); os.IsNotExist(err) {
+			err = ioutil.WriteFile(primaryBuilderNinjaGlobFile, nil, 0666)
+			if err != nil {
+				ctx.Errorf("Failed to create empty ninja file: %s", err)
+			}
+		}
+
+		ctx.AddSubninja(primaryBuilderNinjaGlobFile)
+
+		// Build the main build.ninja
+		ctx.Build(pctx, blueprint.BuildParams{
+			Rule:    generateBuildNinja,
+			Outputs: []string{mainNinjaFile},
+			Inputs:  []string{topLevelBlueprints},
+			Args: map[string]string{
+				"builder":  primaryBuilderFile,
+				"extra":    primaryBuilderExtraFlags,
+				"globFile": primaryBuilderNinjaGlobFile,
+			},
+		})
+	}
 
 	if s.config.stage == StageMain {
 		if primaryBuilderName == "minibp" {

bootstrap/build.ninja

@@ -7,8 +7,11 @@
 
 ninja_required_version = 1.7.0
 
+myGlobs = ${bootstrapBuildDir}/.minibootstrap/build-globs.ninja
+subninja ${myGlobs}
+
 rule build.ninja
-    command = ${builder} ${extraArgs} -b ${bootstrapBuildDir} -n ${builddir} -d ${out}.d -o ${out} ${in}
+    command = ${builder} ${extraArgs} -b ${bootstrapBuildDir} -n ${builddir} -d ${out}.d -globFile ${myGlobs} -o ${out} ${in}
     deps = gcc
     depfile = ${out}.d
     description = ${builder} ${out}

bootstrap/cleanup.go

@@ -30,9 +30,9 @@ const logFileName = ".ninja_log"
 
 // removeAbandonedFilesUnder removes any files that appear in the Ninja log, and
 // are prefixed with one of the `under` entries, but that are not currently
-// build targets.
+// build targets, or in `exempt`
 func removeAbandonedFilesUnder(ctx *blueprint.Context, config *Config,
-	srcDir string, under []string) error {
+	srcDir string, under, exempt []string) error {
 
 	if len(under) == 0 {
 		return nil
@@ -57,6 +57,10 @@ func removeAbandonedFilesUnder(ctx *blueprint.Context, config *Config,
 		replacedTarget := replacer.Replace(target)
 		targets[filepath.Clean(replacedTarget)] = true
 	}
+	for _, target := range exempt {
+		replacedTarget := replacer.Replace(target)
+		targets[filepath.Clean(replacedTarget)] = true
+	}
 
 	filePaths, err := parseNinjaLog(ninjaBuildDir, under)
 	if err != nil {

bootstrap/command.go

@@ -32,6 +32,7 @@ import (
 
 var (
 	outFile        string
+	globFile       string
 	depFile        string
 	docFile        string
 	cpuprofile     string
@@ -48,6 +49,7 @@ var (
 
 func init() {
 	flag.StringVar(&outFile, "o", "build.ninja", "the Ninja file to output")
+	flag.StringVar(&globFile, "globFile", "build-globs.ninja", "the Ninja file of globs to output")
 	flag.StringVar(&BuildDir, "b", ".", "the build output directory")
 	flag.StringVar(&NinjaBuildDir, "n", "", "the ninja builddir directory")
 	flag.StringVar(&depFile, "d", "", "the dependency file to output")
@@ -179,6 +181,18 @@ func Main(ctx *blueprint.Context, config interface{}, extraNinjaFileDeps ...stri
 		fatalf("error writing %s: %s", outFile, err)
 	}
 
+	if globFile != "" {
+		buffer, errs := generateGlobNinjaFile(ctx.Globs)
+		if len(errs) > 0 {
+			fatalErrors(errs)
+		}
+
+		err = ioutil.WriteFile(globFile, buffer, outFilePermissions)
+		if err != nil {
+			fatalf("error writing %s: %s", outFile, err)
+		}
+	}
+
 	if depFile != "" {
 		err := deptools.WriteDepFile(depFile, outFile, deps)
 		if err != nil {
@@ -187,8 +201,8 @@ func Main(ctx *blueprint.Context, config interface{}, extraNinjaFileDeps ...stri
 	}
 
 	if c, ok := config.(ConfigRemoveAbandonedFilesUnder); ok {
-		under := c.RemoveAbandonedFilesUnder()
-		err := removeAbandonedFilesUnder(ctx, bootstrapConfig, SrcDir, under)
+		under, except := c.RemoveAbandonedFilesUnder()
+		err := removeAbandonedFilesUnder(ctx, bootstrapConfig, SrcDir, under, except)
 		if err != nil {
 			fatalf("error removing abandoned files: %s", err)
 		}

bootstrap/config.go

@@ -69,10 +69,11 @@ type ConfigInterface interface {
 }
 
 type ConfigRemoveAbandonedFilesUnder interface {
-	// RemoveAbandonedFilesUnder should return a slice of path prefixes that
-	// will be cleaned of files that are no longer active targets, but are
-	// listed in the .ninja_log.
-	RemoveAbandonedFilesUnder() []string
+	// RemoveAbandonedFilesUnder should return two slices:
+	// - a slice of path prefixes that will be cleaned of files that are no
+	//   longer active targets, but are listed in the .ninja_log.
+	// - a slice of paths that are exempt from cleaning
+	RemoveAbandonedFilesUnder() (under, except []string)
 }
 
 type ConfigBlueprintToolLocation interface {

bootstrap/doc.go

@@ -120,23 +120,27 @@
 //      - Runs .bootstrap/build.ninja to build and run the primary builder
 //      - Runs build.ninja to build your code
 //
-// Microfactory takes care of building an up to date version of `minibp` under
-// the .minibootstrap/ directory.
+// Microfactory takes care of building an up to date version of `minibp` and
+// `bpglob` under the .minibootstrap/ directory.
 //
 // During <builddir>/.minibootstrap/build.ninja, the following actions are
 // taken, if necessary:
 //
 //      - Run minibp to generate .bootstrap/build.ninja (Primary stage)
+//      - Includes .minibootstrap/build-globs.ninja, which defines rules to
+//        run bpglob during incremental builds. These outputs are listed in
+//        the dependency file output by minibp.
 //
 // During the <builddir>/.bootstrap/build.ninja, the following actions are
 // taken, if necessary:
 //
-//      - Rebuild .bootstrap/build.ninja, usually due to globs changing --
-//        other dependencies will trigger it to be built during minibootstrap
 //      - Build the primary builder, anything marked `default: true`, and
 //        any dependencies.
 //      - Run the primary builder to generate build.ninja
 //      - Run the primary builder to extract documentation
+//      - Includes .bootstrap/build-globs.ninja, which defines rules to run
+//        bpglob during incremental builds. These outputs are listed in the
+//        dependency file output by the primary builder.
 //
 // Then the main stage is at <builddir>/build.ninja, and will contain all the
 // rules generated by the primary builder. In addition, the bootstrap code

bootstrap/glob.go

@@ -15,6 +15,7 @@
 package bootstrap
 
 import (
+	"bytes"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -40,7 +41,7 @@ import (
 // in a build failure with a "missing and no known rule to make it" error.
 
 var (
-	globCmd = filepath.Join("$BinDir", "bpglob")
+	globCmd = filepath.Join(miniBootstrapDir, "bpglob")
 
 	// globRule rule traverses directories to produce a list of files that match $glob
 	// and writes it to $out if it has changed, and writes the directories to $out.d
@@ -111,6 +112,7 @@ func joinWithPrefixAndQuote(strs []string, prefix string) string {
 // primary builder if the results change.
 type globSingleton struct {
 	globLister func() []blueprint.GlobPath
+	writeRule  bool
 }
 
 func globSingletonFactory(ctx *blueprint.Context) func() blueprint.Singleton {
@@ -124,15 +126,52 @@ func globSingletonFactory(ctx *blueprint.Context) func() blueprint.Singleton {
 func (s *globSingleton) GenerateBuildActions(ctx blueprint.SingletonContext) {
 	for _, g := range s.globLister() {
 		fileListFile := filepath.Join(BuildDir, ".glob", g.Name)
-		depFile := fileListFile + ".d"
 
-		fileList := strings.Join(g.Files, "\n") + "\n"
-		pathtools.WriteFileIfChanged(fileListFile, []byte(fileList), 0666)
-		deptools.WriteDepFile(depFile, fileListFile, g.Deps)
+		if s.writeRule {
+			depFile := fileListFile + ".d"
 
-		GlobFile(ctx, g.Pattern, g.Excludes, fileListFile, depFile)
+			fileList := strings.Join(g.Files, "\n") + "\n"
+			pathtools.WriteFileIfChanged(fileListFile, []byte(fileList), 0666)
+			deptools.WriteDepFile(depFile, fileListFile, g.Deps)
 
-		// Make build.ninja depend on the fileListFile
-		ctx.AddNinjaFileDeps(fileListFile)
+			GlobFile(ctx, g.Pattern, g.Excludes, fileListFile, depFile)
+		} else {
+			// Make build.ninja depend on the fileListFile
+			ctx.AddNinjaFileDeps(fileListFile)
+		}
+	}
+}
+
+func generateGlobNinjaFile(globLister func() []blueprint.GlobPath) ([]byte, []error) {
+	ctx := blueprint.NewContext()
+	ctx.RegisterSingletonType("glob", func() blueprint.Singleton {
+		return &globSingleton{
+			globLister: globLister,
+			writeRule:  true,
+		}
+	})
+
+	extraDeps, errs := ctx.ResolveDependencies(nil)
+	if len(extraDeps) > 0 {
+		return nil, []error{fmt.Errorf("shouldn't have extra deps")}
 	}
+	if len(errs) > 0 {
+		return nil, errs
+	}
+
+	extraDeps, errs = ctx.PrepareBuildActions(nil)
+	if len(extraDeps) > 0 {
+		return nil, []error{fmt.Errorf("shouldn't have extra deps")}
+	}
+	if len(errs) > 0 {
+		return nil, errs
+	}
+
+	buf := bytes.NewBuffer(nil)
+	err := ctx.WriteBuildFile(buf)
+	if err != nil {
+		return nil, []error{err}
+	}
+
+	return buf.Bytes(), nil
 }

bootstrap/minibp/main.go

@@ -37,8 +37,12 @@ func (c Config) GeneratingPrimaryBuilder() bool {
 	return c.generatingPrimaryBuilder
 }
 
-func (c Config) RemoveAbandonedFilesUnder() []string {
-	return []string{filepath.Join(bootstrap.BuildDir, ".bootstrap")}
+func (c Config) RemoveAbandonedFilesUnder() (under, exempt []string) {
+	if c.generatingPrimaryBuilder {
+		under = []string{filepath.Join(bootstrap.BuildDir, ".bootstrap")}
+		exempt = []string{filepath.Join(bootstrap.BuildDir, ".bootstrap", "build.ninja")}
+	}
+	return
 }
 
 func main() {

context.go

@@ -102,6 +102,8 @@ type Context struct {
 	requiredNinjaMinor int          // For the ninja_required_version variable
 	requiredNinjaMicro int          // For the ninja_required_version variable
 
+	subninjas []string
+
 	// set lazily by sortedModuleGroups
 	cachedSortedModuleGroups []*moduleGroup
 
@@ -2939,6 +2941,11 @@ func (c *Context) WriteBuildFile(w io.Writer) error {
 		return err
 	}
 
+	err = c.writeSubninjas(nw)
+	if err != nil {
+		return err
+	}
+
 	// TODO: Group the globals by package.
 
 	err = c.writeGlobalVariables(nw)
@@ -3048,6 +3055,13 @@ func (c *Context) writeNinjaRequiredVersion(nw *ninjaWriter) error {
 	return nw.BlankLine()
 }
 
+func (c *Context) writeSubninjas(nw *ninjaWriter) error {
+	for _, subninja := range c.subninjas {
+		nw.Subninja(subninja)
+	}
+	return nw.BlankLine()
+}
+
 func (c *Context) writeBuildDir(nw *ninjaWriter) error {
 	if c.ninjaBuildDir != nil {
 		err := nw.Assign("builddir", c.ninjaBuildDir.Value(c.pkgNames))

ninja_writer.go

@@ -193,6 +193,12 @@ func (n *ninjaWriter) Default(targets ...string) error {
 	return wrapper.Flush()
 }
 
+func (n *ninjaWriter) Subninja(file string) error {
+	n.justDidBlankLine = false
+	_, err := fmt.Fprintf(n.writer, "subninja %s\n", file)
+	return err
+}
+
 func (n *ninjaWriter) BlankLine() (err error) {
 	// We don't output multiple blank lines in a row.
 	if !n.justDidBlankLine {

ninja_writer_test.go

@@ -72,6 +72,12 @@ var ninjaWriterTestCases = []struct {
 		},
 		output: "    foo = bar\n",
 	},
+	{
+		input: func(w *ninjaWriter) {
+			ck(w.Subninja("build.ninja"))
+		},
+		output: "subninja build.ninja\n",
+	},
 	{
 		input: func(w *ninjaWriter) {
 			ck(w.BlankLine())