tools/integration/fint/build.go - fuchsia - Git at Google

 // Copyright 2021 The Fuchsia 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 fint

 import (
 	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
 	"io"
 	"math"
 	"net/url"
 	"os"
 	"path/filepath"
 	"sort"
 	"strings"
 	"time"

 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/structpb"

 	"go.fuchsia.dev/fuchsia/tools/build"
 	fintpb "go.fuchsia.dev/fuchsia/tools/integration/fint/proto"
 	"go.fuchsia.dev/fuchsia/tools/lib/hostplatform"
 	"go.fuchsia.dev/fuchsia/tools/lib/osmisc"
 	"go.fuchsia.dev/fuchsia/tools/lib/subprocess"
 )

 const (
 	// Name of the QEMU kernel image as it appears in images.json.
 	qemuKernelImageName = "qemu-kernel"

 	// ninjaLogPath is the path to the main ninja log relative to the build directory.
 	ninjaLogPath = ".ninja_log"
 )

 var (
 	// Names of images that are used for running on QEMU.
 	qemuImageNames = []string{qemuKernelImageName, "zircon-a"}

 	// Values of the "device_type" zbi_tests.json field that are emulators.
 	emulatorDeviceTypes = []string{"QEMU", "AEMU"}

 	// Extra targets to build when building images. Needed for size checks and tracking.
 	extraTargetsForImages = []string{
 		"build/images:record_filesystem_sizes",
 		"build/images:system_snapshot",
 	}
 )

 type buildModules interface {
 	Archives() []build.Archive
 	GeneratedSources() []string
 	Images() []build.Image
 	PrebuiltBinarySets() []build.PrebuiltBinarySet
 	TestSpecs() []build.TestSpec
 	Tools() build.Tools
 	ZBITests() []build.ZBITest
 }

 // Build runs `ninja` given a static and context spec. It's intended to be
 // consumed as a library function.
 func Build(ctx context.Context, staticSpec *fintpb.Static, contextSpec *fintpb.Context) (*fintpb.BuildArtifacts, error) {
 	platform, err := hostplatform.Name()
 	if err != nil {
 		return nil, err
 	}
 	modules, err := build.NewModules(contextSpec.BuildDir)
 	if err != nil {
 		return nil, err
 	}
 	artifacts, err := buildImpl(ctx, &subprocess.Runner{}, staticSpec, contextSpec, modules, platform)
 	if err != nil && artifacts != nil && artifacts.FailureSummary == "" {
 		// Fall back to using the error text as the failure summary if the
 		// failure summary is unset. It's better than failing without emitting
 		// any information.
 		artifacts.FailureSummary = err.Error()
 	}
 	return artifacts, err
 }

 // buildImpl contains the business logic of `fint build`, extracted into a more
 // easily testable layer.
 func buildImpl(
 	ctx context.Context,
 	runner subprocessRunner,
 	staticSpec *fintpb.Static,
 	contextSpec *fintpb.Context,
 	modules buildModules,
 	platform string,
 ) (*fintpb.BuildArtifacts, error) {
 	artifacts := &fintpb.BuildArtifacts{}

 	targets, targetArtifacts, err := constructNinjaTargets(modules, staticSpec, platform)
 	if err != nil {
 		return artifacts, err
 	}
 	proto.Merge(artifacts, targetArtifacts)

 	artifacts.BuiltTargets = targets
 	// Initialize the map, otherwise it will be nil and attempts to set keys
 	// will fail.
 	artifacts.LogFiles = make(map[string]string)

 	ninjaPath, err := toolAbsPath(modules, contextSpec.BuildDir, platform, "ninja")
 	if err != nil {
 		return artifacts, err
 	}
 	r := ninjaRunner{
 		runner:    runner,
 		ninjaPath: ninjaPath,
 		buildDir:  contextSpec.BuildDir,
 		jobCount:  int(contextSpec.GomaJobCount),
 	}

 	ninjaStartTime := time.Now()
 	var ninjaErr error
 	if contextSpec.ArtifactDir == "" {
 		// If we don't care about collecting artifacts, which is generally the
 		// case when running locally, then there's no need to parse the Ninja
 		// stdout to get the failure message. So let Ninja print directly to
 		// stdout, so it will nicely buffer output when running in a terminal
 		// instead of printing each log on a new line.
 		ninjaErr = r.run(ctx, targets, os.Stdout, os.Stderr)
 	} else {
 		var explainSink io.Writer
 		if staticSpec.Incremental {
 			f, err := os.Create(filepath.Join(contextSpec.ArtifactDir, "explain_output.txt"))
 			if err != nil {
 				return artifacts, err
 			}
 			defer f.Close()
 			artifacts.LogFiles["explain_output.txt"] = f.Name()
 			explainSink = f
 		}
 		artifacts.FailureSummary, ninjaErr = runNinja(
 			ctx,
 			r,
 			targets,
 			// Add -d explain to incremental builds.
 			staticSpec.Incremental,
 			explainSink,
 		)
 	}
 	ninjaDuration := time.Since(ninjaStartTime)
 	artifacts.NinjaDurationSeconds = int32(math.Round(ninjaDuration.Seconds()))

 	// The ninja log is generated automatically by Ninja and its path is
 	// constant relative to the build directory.
 	artifacts.NinjaLogPath = filepath.Join(contextSpec.BuildDir, ninjaLogPath)

 	// As an optimization, we only bother collecting graph and compdb data if we
 	// have a way to return it to the caller. We want to collect this data even
 	// when the build failed.
 	if contextSpec.ArtifactDir != "" {
 		graph := filepath.Join(contextSpec.ArtifactDir, "ninja-graph.dot")
 		if err := ninjaGraph(ctx, r, targets, graph); err != nil {
 			if ninjaErr == nil {
 				return artifacts, err
 			}
 		} else {
 			artifacts.NinjaGraphPath = graph
 		}

 		compdb := filepath.Join(contextSpec.ArtifactDir, "compile-commands.json")
 		if err := ninjaCompdb(ctx, r, compdb); err != nil {
 			if ninjaErr == nil {
 				return artifacts, err
 			}
 		} else {
 			artifacts.NinjaCompdbPath = compdb
 		}
 	}

 	if ninjaErr != nil {
 		return artifacts, ninjaErr
 	}

 	gnPath, err := toolAbsPath(modules, contextSpec.BuildDir, platform, "gn")
 	if err != nil {
 		return artifacts, err
 	}
 	if output, err := gnCheckGenerated(ctx, runner, gnPath, contextSpec.CheckoutDir, contextSpec.BuildDir); err != nil {
 		artifacts.FailureSummary = output
 		return artifacts, err
 	}

 	// saveLogs writes the given set of logs to files in the artifact directory,
 	// and adds each path to the output artifacts.
 	saveLogs := func(logs map[string]string) error {
 		if contextSpec.ArtifactDir == "" {
 			return nil
 		}
 		for name, contents := range logs {
 			dest := filepath.Join(
 				contextSpec.ArtifactDir,
 				url.QueryEscape(strings.ReplaceAll(name, " ", "_")))
 			f, err := osmisc.CreateFile(dest)
 			if err != nil {
 				return err
 			}
 			defer f.Close()
 			if _, err := f.WriteString(contents); err != nil {
 				return fmt.Errorf("failed to write log file %q: %w", name, err)
 			}
 			artifacts.LogFiles[name] = f.Name()
 		}
 		return nil
 	}

 	if !contextSpec.SkipNinjaNoopCheck {
 		noop, logs, err := checkNinjaNoop(ctx, r, targets, hostplatform.IsMac(platform))
 		if err != nil {
 			return artifacts, err
 		}
 		if err := saveLogs(logs); err != nil {
 			return artifacts, err
 		}
 		if !noop {
 			artifacts.FailureSummary = ninjaNoopFailureMessage(platform)
 			return artifacts, fmt.Errorf("ninja build did not converge to no-op")
 		}
 	}

 	// TODO(olivernewman): Figure out a way to skip this analysis when the
 	// caller doesn't care about running tests, or just wants to run all tests
 	// in the same way regardless of any build graph analysis. In the meantime
 	// it's not the end of the world to do this analysis unnecessarily, since it
 	// only takes ~10 seconds and we do use the results most of the time,
 	// including on all the slowest infra builders.
 	if contextSpec.ArtifactDir != "" && len(contextSpec.ChangedFiles) > 0 && len(modules.TestSpecs()) > 0 {
 		var tests []build.Test
 		for _, t := range modules.TestSpecs() {
 			tests = append(tests, t.Test)
 		}
 		var affectedFiles []string
 		for _, f := range contextSpec.ChangedFiles {
 			absPath := filepath.Join(contextSpec.CheckoutDir, f.Path)
 			affectedFiles = append(affectedFiles, absPath)
 		}
 		result, err := affectedTestsNoWork(ctx, r, tests, affectedFiles, targets)
 		if err != nil {
 			return artifacts, err
 		}
 		if err := saveLogs(result.logs); err != nil {
 			return artifacts, err
 		}
 		artifacts.AffectedTests = result.affectedTests
 		artifacts.BuildNotAffected = result.noWork
 	}

 	return artifacts, nil
 }

 func ninjaNoopFailureMessage(platform string) string {
 	summaryLines := []string{
 		"Ninja build did not converge to no-op.",
 		"See: https://fuchsia.dev/fuchsia-src/development/build/ninja_no_op",
 	}
 	if hostplatform.IsMac(platform) {
 		summaryLines = append(
 			summaryLines,
 			"If this failure is specific to Mac, confirm that it's not related to fxbug.dev/61784.",
 		)
 	}
 	return strings.Join(summaryLines, "\n")
 }

 // constructNinjaTargets determines which targets to build based on the static
 // spec fields and the contents of the build API files. It emits a
 // BuildArtifacts protobuf with only a subset of fields set that should be
 // merged into an existing BuildArtifacts protobuf struct by the caller, since
 // this is more clean than taking a BuildARtifacts pointer as input and
 // modifying it.
 func constructNinjaTargets(
 	modules buildModules,
 	staticSpec *fintpb.Static,
 	platform string,
 ) ([]string, *fintpb.BuildArtifacts, error) {
 	var targets []string
 	var artifacts fintpb.BuildArtifacts

 	if staticSpec.IncludeDefaultNinjaTarget {
 		targets = append(targets, ":default")
 	}

 	if staticSpec.IncludeImages {
 		targets = append(targets, extraTargetsForImages...)

 		for _, image := range modules.Images() {
 			if isTestingImage(image, staticSpec.Pave) {
 				targets = append(targets, image.Path)
 				imageStruct, err := toStructPB(image)
 				if err != nil {
 					return nil, nil, err
 				}
 				artifacts.BuiltImages = append(artifacts.BuiltImages, imageStruct)
 			}
 		}

 		// TODO(fxbug.dev/43568): Remove once it is always false, and move
 		// "build/images:updates" into `extraTargetsForImages`.
 		if staticSpec.IncludeArchives {
 			archivesToBuild := []string{
 				"archive",  // Images and scripts for paving/netbooting.
 				"packages", // Package metadata, blobs, and tools.
 			}
 			for _, archive := range modules.Archives() {
 				if contains(archivesToBuild, archive.Name) && archive.Type == "tgz" {
 					targets = append(targets, archive.Path)
 					archiveStruct, err := toStructPB(archive)
 					if err != nil {
 						return nil, nil, err
 					}
 					artifacts.BuiltArchives = append(artifacts.BuiltArchives, archiveStruct)
 				}
 			}
 		} else {
 			targets = append(targets, "build/images:updates")
 		}
 	}

 	if staticSpec.IncludeGeneratedSources {
 		targets = append(targets, modules.GeneratedSources()...)
 	}

 	if staticSpec.IncludeHostTests {
 		for _, testSpec := range modules.TestSpecs() {
 			if testSpec.OS != "fuchsia" {
 				targets = append(targets, testSpec.Path)
 			}
 		}
 	}

 	if staticSpec.IncludeZbiTests {
 		artifacts.ZbiTestQemuKernelImages = map[string]*structpb.Struct{}
 		for _, zbiTest := range modules.ZBITests() {
 			targets = append(targets, zbiTest.Path)
 			for _, dt := range zbiTest.DeviceTypes {
 				if !contains(emulatorDeviceTypes, dt) {
 					continue
 				}
 				// A ZBI test may specify another image to be run as the QEMU
 				// kernel. Ensure that it is built.
 				img, err := getQEMUKernelImage(zbiTest, modules)
 				if err != nil {
 					return nil, nil, err
 				}
 				imgPB, err := toStructPB(img)
 				if err != nil {
 					return nil, nil, err
 				}
 				artifacts.ZbiTestQemuKernelImages[zbiTest.Name] = imgPB
 				targets = append(targets, img.Path)
 				break
 			}
 		}

 		var zedbootImages []*structpb.Struct
 		for _, img := range modules.Images() {
 			if len(img.PaveZedbootArgs) == 0 {
 				continue
 			}
 			// TODO(fxbug.dev/68977): Remove when we can find a way to boot from the
 			// same slot we pave zedboot to.
 			if staticSpec.TargetArch == fintpb.Static_ARM64 && contains(img.PaveZedbootArgs, "--zircona") {
 				img.PaveZedbootArgs = append(img.PaveZedbootArgs, "--zirconb")
 			}
 			imgPB, err := toStructPB(img)
 			if err != nil {
 				return nil, nil, err
 			}
 			zedbootImages = append(zedbootImages, imgPB)
 			targets = append(targets, img.Path)
 		}
 		if len(zedbootImages) == 0 {
 			return nil, nil, fmt.Errorf("missing zedboot pave images")
 		}
 		artifacts.BuiltZedbootImages = zedbootImages
 	}

 	if staticSpec.IncludePrebuiltBinaryManifests {
 		for _, manifest := range modules.PrebuiltBinarySets() {
 			targets = append(targets, manifest.Manifest)
 		}
 	}

 	// We only support specifying tools for the current platform. Tools
 	// needed for other platforms can be included in the build indirectly
 	// via higher-level targets.
 	for _, tool := range staticSpec.Tools {
 		path, err := modules.Tools().LookupPath(platform, tool)
 		if err != nil {
 			return nil, nil, err
 		}
 		targets = append(targets, path)
 	}

 	targets = append(targets, staticSpec.NinjaTargets...)
 	return removeDuplicates(targets), &artifacts, nil
 }

 // isTestingImage determines whether an image is necessary for testing Fuchsia.
 //
 // The `pave` argument indicates whether images will be used for paving (as
 // opposed to netbooting).
 //
 // If an image is used in paving or netbooting, its manifest entry will specify
 // what flags to pass to the bootserver when doing so.
 func isTestingImage(image build.Image, pave bool) bool {
 	switch {
 	case len(image.PaveZedbootArgs) != 0: // Used by catalyst.
 		return true
 	case pave && len(image.PaveArgs) != 0: // Used for paving.
 		return true
 	case !pave && len(image.NetbootArgs) != 0: // Used for netboot.
 		return true
 	case contains(qemuImageNames, image.Name): // Used for QEMU.
 		return true
 	case image.Name == "uefi-disk": // Used for GCE.
 		return true
 	case image.Type == "script":
 		// In order for a user to provision without Zedboot the scripts are
 		// needed too, so we want to include them such that artifactory can
 		// upload them. This covers scripts like "pave.sh", "flash.sh", etc.
 		if pave && strings.Contains(image.Name, "netboot") {
 			// If we're paving then we shouldn't build any netboot scripts,
 			// because they would pull netboot images into the build graph that
 			// take a while to build and that we don't actually need.
 			return false
 		}
 		return true
 	// Allow-list a specific set of zbi images that are used for testing.
 	case image.Type == "zbi" && image.Name == "overnet":
 		return true
 	default:
 		return false
 	}
 }

 // toolAbsPath returns the absolute path to a tool specified in tool_paths.json.
 //
 // Note that not all tools in tool_paths.json can be assumed to be present in
 // the build directory prior to `fint build` running because only a subset of
 // them are prebuilts, and the rest are built from source.
 func toolAbsPath(modules buildModules, buildDir, platform, tool string) (string, error) {
 	path, err := modules.Tools().LookupPath(platform, tool)
 	if err != nil {
 		return "", err
 	}
 	return filepath.Abs(filepath.Join(buildDir, path))
 }

 // getQEMUKernelImage iterates through images.json to find the QEMU kernel image
 // for the given ZBI test.
 func getQEMUKernelImage(zbiTest build.ZBITest, modules buildModules) (build.Image, error) {
 	var images []build.Image
 	for _, img := range modules.Images() {
 		include := false
 		if zbiTest.QEMUKernelLabel != "" {
 			include = img.Label == zbiTest.QEMUKernelLabel
 		} else {
 			include = img.Name == qemuKernelImageName
 		}
 		if include {
 			images = append(images, img)
 		}
 	}
 	// If 'qemu_kernel_label' is specified, precisely one image with that
 	// label must exist; else, precisely one with the name of "qemu-kernel"
 	// must exist.
 	if len(images) == 0 {
 		return build.Image{}, fmt.Errorf("no QEMU kernel match found for zbi test %q", zbiTest.Name)
 	} else if len(images) > 1 {
 		return build.Image{}, fmt.Errorf("multiple QEMU kernel matches found for zbi test %q", zbiTest.Name)
 	}
 	img := images[0]
 	img.Name = qemuKernelImageName
 	img.Type = "kernel"
 	return img, nil
 }

 // toStructPB converts a Go struct to a Struct protobuf. Unfortunately, short of
 // using some complicated `reflect` logic, the only way to do this conversion is
 // by using JSON as an intermediate format.
 func toStructPB(s interface{}) (*structpb.Struct, error) {
 	j, err := json.Marshal(s)
 	if err != nil {
 		return nil, err
 	}
 	var m map[string]interface{}
 	if err := json.Unmarshal(j, &m); err != nil {
 		return nil, err
 	}
 	return structpb.NewStruct(m)
 }

 // removeDuplicates rearranges and re-slices the given slice in-place, returning
 // a slice containing only the unique elements of the original slice.
 func removeDuplicates(slice []string) []string {
 	sort.Strings(slice)

 	var numUnique int
 	var previous string
 	for _, str := range slice {
 		if previous == "" || str != previous {
 			slice[numUnique] = str
 			numUnique++
 		}
 		previous = str
 	}

 	return slice[:numUnique]
 }

 // gnCheckGenerated runs `gn check` against a build directory that's already had
 // `ninja` run, to check generated files that weren't available for checking at
 // the time we ran `fint set`.
 //
 // It returns the stdout of the subprocess.
 func gnCheckGenerated(ctx context.Context, r subprocessRunner, gn, checkoutDir, buildDir string) (string, error) {
 	cmd := []string{
 		gn,
 		"check",
 		buildDir,
 		fmt.Sprintf("--root=%s", checkoutDir),
 		"--check-generated",
 		"--check-system",
 	}
 	var stdoutBuf bytes.Buffer
 	if err := r.Run(ctx, cmd, io.MultiWriter(&stdoutBuf, os.Stdout), os.Stderr); err != nil {
 		return stdoutBuf.String(), fmt.Errorf("error running `gn check`: %w", err)
 	}
 	return stdoutBuf.String(), nil
 }
	// Copyright 2021 The Fuchsia 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 fint

	import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"math"
	"net/url"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"time"

	"google.golang.org/protobuf/proto"
	"google.golang.org/protobuf/types/known/structpb"

	"go.fuchsia.dev/fuchsia/tools/build"
	fintpb "go.fuchsia.dev/fuchsia/tools/integration/fint/proto"
	"go.fuchsia.dev/fuchsia/tools/lib/hostplatform"
	"go.fuchsia.dev/fuchsia/tools/lib/osmisc"
	"go.fuchsia.dev/fuchsia/tools/lib/subprocess"
	)

	const (
	// Name of the QEMU kernel image as it appears in images.json.
	qemuKernelImageName = "qemu-kernel"

	// ninjaLogPath is the path to the main ninja log relative to the build directory.
	ninjaLogPath = ".ninja_log"
	)

	var (
	// Names of images that are used for running on QEMU.
	qemuImageNames = []string{qemuKernelImageName, "zircon-a"}

	// Values of the "device_type" zbi_tests.json field that are emulators.
	emulatorDeviceTypes = []string{"QEMU", "AEMU"}

	// Extra targets to build when building images. Needed for size checks and tracking.
	extraTargetsForImages = []string{
	"build/images:record_filesystem_sizes",
	"build/images:system_snapshot",
	}
	)

	type buildModules interface {
	Archives() []build.Archive
	GeneratedSources() []string
	Images() []build.Image
	PrebuiltBinarySets() []build.PrebuiltBinarySet
	TestSpecs() []build.TestSpec
	Tools() build.Tools
	ZBITests() []build.ZBITest
	}

	// Build runs `ninja` given a static and context spec. It's intended to be
	// consumed as a library function.
	func Build(ctx context.Context, staticSpec fintpb.Static, contextSpec fintpb.Context) (*fintpb.BuildArtifacts, error) {
	platform, err := hostplatform.Name()
	if err != nil {
	return nil, err
	}
	modules, err := build.NewModules(contextSpec.BuildDir)
	if err != nil {
	return nil, err
	}
	artifacts, err := buildImpl(ctx, &subprocess.Runner{}, staticSpec, contextSpec, modules, platform)
	if err != nil && artifacts != nil && artifacts.FailureSummary == "" {
	// Fall back to using the error text as the failure summary if the
	// failure summary is unset. It's better than failing without emitting
	// any information.
	artifacts.FailureSummary = err.Error()
	}
	return artifacts, err
	}

	// buildImpl contains the business logic of `fint build`, extracted into a more
	// easily testable layer.
	func buildImpl(
	ctx context.Context,
	runner subprocessRunner,
	staticSpec *fintpb.Static,
	contextSpec *fintpb.Context,
	modules buildModules,
	platform string,
	) (*fintpb.BuildArtifacts, error) {
	artifacts := &fintpb.BuildArtifacts{}

	targets, targetArtifacts, err := constructNinjaTargets(modules, staticSpec, platform)
	if err != nil {
	return artifacts, err
	}
	proto.Merge(artifacts, targetArtifacts)

	artifacts.BuiltTargets = targets
	// Initialize the map, otherwise it will be nil and attempts to set keys
	// will fail.
	artifacts.LogFiles = make(map[string]string)

	ninjaPath, err := toolAbsPath(modules, contextSpec.BuildDir, platform, "ninja")
	if err != nil {
	return artifacts, err
	}
	r := ninjaRunner{
	runner: runner,
	ninjaPath: ninjaPath,
	buildDir: contextSpec.BuildDir,
	jobCount: int(contextSpec.GomaJobCount),
	}

	ninjaStartTime := time.Now()
	var ninjaErr error
	if contextSpec.ArtifactDir == "" {
	// If we don't care about collecting artifacts, which is generally the
	// case when running locally, then there's no need to parse the Ninja
	// stdout to get the failure message. So let Ninja print directly to
	// stdout, so it will nicely buffer output when running in a terminal
	// instead of printing each log on a new line.
	ninjaErr = r.run(ctx, targets, os.Stdout, os.Stderr)
	} else {
	var explainSink io.Writer
	if staticSpec.Incremental {
	f, err := os.Create(filepath.Join(contextSpec.ArtifactDir, "explain_output.txt"))
	if err != nil {
	return artifacts, err
	}
	defer f.Close()
	artifacts.LogFiles["explain_output.txt"] = f.Name()
	explainSink = f
	}
	artifacts.FailureSummary, ninjaErr = runNinja(
	ctx,
	r,
	targets,
	// Add -d explain to incremental builds.
	staticSpec.Incremental,
	explainSink,
	)
	}
	ninjaDuration := time.Since(ninjaStartTime)
	artifacts.NinjaDurationSeconds = int32(math.Round(ninjaDuration.Seconds()))

	// The ninja log is generated automatically by Ninja and its path is
	// constant relative to the build directory.
	artifacts.NinjaLogPath = filepath.Join(contextSpec.BuildDir, ninjaLogPath)

	// As an optimization, we only bother collecting graph and compdb data if we
	// have a way to return it to the caller. We want to collect this data even
	// when the build failed.
	if contextSpec.ArtifactDir != "" {
	graph := filepath.Join(contextSpec.ArtifactDir, "ninja-graph.dot")
	if err := ninjaGraph(ctx, r, targets, graph); err != nil {
	if ninjaErr == nil {
	return artifacts, err
	}
	} else {
	artifacts.NinjaGraphPath = graph
	}

	compdb := filepath.Join(contextSpec.ArtifactDir, "compile-commands.json")
	if err := ninjaCompdb(ctx, r, compdb); err != nil {
	if ninjaErr == nil {
	return artifacts, err
	}
	} else {
	artifacts.NinjaCompdbPath = compdb
	}
	}

	if ninjaErr != nil {
	return artifacts, ninjaErr
	}

	gnPath, err := toolAbsPath(modules, contextSpec.BuildDir, platform, "gn")
	if err != nil {
	return artifacts, err
	}
	if output, err := gnCheckGenerated(ctx, runner, gnPath, contextSpec.CheckoutDir, contextSpec.BuildDir); err != nil {
	artifacts.FailureSummary = output
	return artifacts, err
	}

	// saveLogs writes the given set of logs to files in the artifact directory,
	// and adds each path to the output artifacts.
	saveLogs := func(logs map[string]string) error {
	if contextSpec.ArtifactDir == "" {
	return nil
	}
	for name, contents := range logs {
	dest := filepath.Join(
	contextSpec.ArtifactDir,
	url.QueryEscape(strings.ReplaceAll(name, " ", "_")))
	f, err := osmisc.CreateFile(dest)
	if err != nil {
	return err
	}
	defer f.Close()
	if _, err := f.WriteString(contents); err != nil {
	return fmt.Errorf("failed to write log file %q: %w", name, err)
	}
	artifacts.LogFiles[name] = f.Name()
	}
	return nil
	}

	if !contextSpec.SkipNinjaNoopCheck {
	noop, logs, err := checkNinjaNoop(ctx, r, targets, hostplatform.IsMac(platform))
	if err != nil {
	return artifacts, err
	}
	if err := saveLogs(logs); err != nil {
	return artifacts, err
	}
	if !noop {
	artifacts.FailureSummary = ninjaNoopFailureMessage(platform)
	return artifacts, fmt.Errorf("ninja build did not converge to no-op")
	}
	}

	// TODO(olivernewman): Figure out a way to skip this analysis when the
	// caller doesn't care about running tests, or just wants to run all tests
	// in the same way regardless of any build graph analysis. In the meantime
	// it's not the end of the world to do this analysis unnecessarily, since it
	// only takes ~10 seconds and we do use the results most of the time,
	// including on all the slowest infra builders.
	if contextSpec.ArtifactDir != "" && len(contextSpec.ChangedFiles) > 0 && len(modules.TestSpecs()) > 0 {
	var tests []build.Test
	for _, t := range modules.TestSpecs() {
	tests = append(tests, t.Test)
	}
	var affectedFiles []string
	for _, f := range contextSpec.ChangedFiles {
	absPath := filepath.Join(contextSpec.CheckoutDir, f.Path)
	affectedFiles = append(affectedFiles, absPath)
	}
	result, err := affectedTestsNoWork(ctx, r, tests, affectedFiles, targets)
	if err != nil {
	return artifacts, err
	}
	if err := saveLogs(result.logs); err != nil {
	return artifacts, err
	}
	artifacts.AffectedTests = result.affectedTests
	artifacts.BuildNotAffected = result.noWork
	}

	return artifacts, nil
	}

	func ninjaNoopFailureMessage(platform string) string {
	summaryLines := []string{
	"Ninja build did not converge to no-op.",
	"See: https://fuchsia.dev/fuchsia-src/development/build/ninja_no_op",
	}
	if hostplatform.IsMac(platform) {
	summaryLines = append(
	summaryLines,
	"If this failure is specific to Mac, confirm that it's not related to fxbug.dev/61784.",
	)
	}
	return strings.Join(summaryLines, "\n")
	}

	// constructNinjaTargets determines which targets to build based on the static
	// spec fields and the contents of the build API files. It emits a
	// BuildArtifacts protobuf with only a subset of fields set that should be
	// merged into an existing BuildArtifacts protobuf struct by the caller, since
	// this is more clean than taking a BuildARtifacts pointer as input and
	// modifying it.
	func constructNinjaTargets(
	modules buildModules,
	staticSpec *fintpb.Static,
	platform string,
	) ([]string, *fintpb.BuildArtifacts, error) {
	var targets []string
	var artifacts fintpb.BuildArtifacts

	if staticSpec.IncludeDefaultNinjaTarget {
	targets = append(targets, ":default")
	}

	if staticSpec.IncludeImages {
	targets = append(targets, extraTargetsForImages...)

	for _, image := range modules.Images() {
	if isTestingImage(image, staticSpec.Pave) {
	targets = append(targets, image.Path)
	imageStruct, err := toStructPB(image)
	if err != nil {
	return nil, nil, err
	}
	artifacts.BuiltImages = append(artifacts.BuiltImages, imageStruct)
	}
	}

	// TODO(fxbug.dev/43568): Remove once it is always false, and move
	// "build/images:updates" into `extraTargetsForImages`.
	if staticSpec.IncludeArchives {
	archivesToBuild := []string{
	"archive", // Images and scripts for paving/netbooting.
	"packages", // Package metadata, blobs, and tools.
	}
	for _, archive := range modules.Archives() {
	if contains(archivesToBuild, archive.Name) && archive.Type == "tgz" {
	targets = append(targets, archive.Path)
	archiveStruct, err := toStructPB(archive)
	if err != nil {
	return nil, nil, err
	}
	artifacts.BuiltArchives = append(artifacts.BuiltArchives, archiveStruct)
	}
	}
	} else {
	targets = append(targets, "build/images:updates")
	}
	}

	if staticSpec.IncludeGeneratedSources {
	targets = append(targets, modules.GeneratedSources()...)
	}

	if staticSpec.IncludeHostTests {
	for _, testSpec := range modules.TestSpecs() {
	if testSpec.OS != "fuchsia" {
	targets = append(targets, testSpec.Path)
	}
	}
	}

	if staticSpec.IncludeZbiTests {
	artifacts.ZbiTestQemuKernelImages = map[string]*structpb.Struct{}
	for _, zbiTest := range modules.ZBITests() {
	targets = append(targets, zbiTest.Path)
	for _, dt := range zbiTest.DeviceTypes {
	if !contains(emulatorDeviceTypes, dt) {
	continue
	}
	// A ZBI test may specify another image to be run as the QEMU
	// kernel. Ensure that it is built.
	img, err := getQEMUKernelImage(zbiTest, modules)
	if err != nil {
	return nil, nil, err
	}
	imgPB, err := toStructPB(img)
	if err != nil {
	return nil, nil, err
	}
	artifacts.ZbiTestQemuKernelImages[zbiTest.Name] = imgPB
	targets = append(targets, img.Path)
	break
	}
	}

	var zedbootImages []*structpb.Struct
	for _, img := range modules.Images() {
	if len(img.PaveZedbootArgs) == 0 {
	continue
	}
	// TODO(fxbug.dev/68977): Remove when we can find a way to boot from the
	// same slot we pave zedboot to.
	if staticSpec.TargetArch == fintpb.Static_ARM64 && contains(img.PaveZedbootArgs, "--zircona") {
	img.PaveZedbootArgs = append(img.PaveZedbootArgs, "--zirconb")
	}
	imgPB, err := toStructPB(img)
	if err != nil {
	return nil, nil, err
	}
	zedbootImages = append(zedbootImages, imgPB)
	targets = append(targets, img.Path)
	}
	if len(zedbootImages) == 0 {
	return nil, nil, fmt.Errorf("missing zedboot pave images")
	}
	artifacts.BuiltZedbootImages = zedbootImages
	}

	if staticSpec.IncludePrebuiltBinaryManifests {
	for _, manifest := range modules.PrebuiltBinarySets() {
	targets = append(targets, manifest.Manifest)
	}
	}

	// We only support specifying tools for the current platform. Tools
	// needed for other platforms can be included in the build indirectly
	// via higher-level targets.
	for _, tool := range staticSpec.Tools {
	path, err := modules.Tools().LookupPath(platform, tool)
	if err != nil {
	return nil, nil, err
	}
	targets = append(targets, path)
	}

	targets = append(targets, staticSpec.NinjaTargets...)
	return removeDuplicates(targets), &artifacts, nil
	}

	// isTestingImage determines whether an image is necessary for testing Fuchsia.
	//
	// The `pave` argument indicates whether images will be used for paving (as
	// opposed to netbooting).
	//
	// If an image is used in paving or netbooting, its manifest entry will specify
	// what flags to pass to the bootserver when doing so.
	func isTestingImage(image build.Image, pave bool) bool {
	switch {
	case len(image.PaveZedbootArgs) != 0: // Used by catalyst.
	return true
	case pave && len(image.PaveArgs) != 0: // Used for paving.
	return true
	case !pave && len(image.NetbootArgs) != 0: // Used for netboot.
	return true
	case contains(qemuImageNames, image.Name): // Used for QEMU.
	return true
	case image.Name == "uefi-disk": // Used for GCE.
	return true
	case image.Type == "script":
	// In order for a user to provision without Zedboot the scripts are
	// needed too, so we want to include them such that artifactory can
	// upload them. This covers scripts like "pave.sh", "flash.sh", etc.
	if pave && strings.Contains(image.Name, "netboot") {
	// If we're paving then we shouldn't build any netboot scripts,
	// because they would pull netboot images into the build graph that
	// take a while to build and that we don't actually need.
	return false
	}
	return true
	// Allow-list a specific set of zbi images that are used for testing.
	case image.Type == "zbi" && image.Name == "overnet":
	return true
	default:
	return false
	}
	}

	// toolAbsPath returns the absolute path to a tool specified in tool_paths.json.
	//
	// Note that not all tools in tool_paths.json can be assumed to be present in
	// the build directory prior to `fint build` running because only a subset of
	// them are prebuilts, and the rest are built from source.
	func toolAbsPath(modules buildModules, buildDir, platform, tool string) (string, error) {
	path, err := modules.Tools().LookupPath(platform, tool)
	if err != nil {
	return "", err
	}
	return filepath.Abs(filepath.Join(buildDir, path))
	}

	// getQEMUKernelImage iterates through images.json to find the QEMU kernel image
	// for the given ZBI test.
	func getQEMUKernelImage(zbiTest build.ZBITest, modules buildModules) (build.Image, error) {
	var images []build.Image
	for _, img := range modules.Images() {
	include := false
	if zbiTest.QEMUKernelLabel != "" {
	include = img.Label == zbiTest.QEMUKernelLabel
	} else {
	include = img.Name == qemuKernelImageName
	}
	if include {
	images = append(images, img)
	}
	}
	// If 'qemu_kernel_label' is specified, precisely one image with that
	// label must exist; else, precisely one with the name of "qemu-kernel"
	// must exist.
	if len(images) == 0 {
	return build.Image{}, fmt.Errorf("no QEMU kernel match found for zbi test %q", zbiTest.Name)
	} else if len(images) > 1 {
	return build.Image{}, fmt.Errorf("multiple QEMU kernel matches found for zbi test %q", zbiTest.Name)
	}
	img := images[0]
	img.Name = qemuKernelImageName
	img.Type = "kernel"
	return img, nil
	}

	// toStructPB converts a Go struct to a Struct protobuf. Unfortunately, short of
	// using some complicated `reflect` logic, the only way to do this conversion is
	// by using JSON as an intermediate format.
	func toStructPB(s interface{}) (*structpb.Struct, error) {
	j, err := json.Marshal(s)
	if err != nil {
	return nil, err
	}
	var m map[string]interface{}
	if err := json.Unmarshal(j, &m); err != nil {
	return nil, err
	}
	return structpb.NewStruct(m)
	}

	// removeDuplicates rearranges and re-slices the given slice in-place, returning
	// a slice containing only the unique elements of the original slice.
	func removeDuplicates(slice []string) []string {
	sort.Strings(slice)

	var numUnique int
	var previous string
	for _, str := range slice {
	if previous == "" \|\| str != previous {
	slice[numUnique] = str
	numUnique++
	}
	previous = str
	}

	return slice[:numUnique]
	}

	// gnCheckGenerated runs `gn check` against a build directory that's already had
	// `ninja` run, to check generated files that weren't available for checking at
	// the time we ran `fint set`.
	//
	// It returns the stdout of the subprocess.
	func gnCheckGenerated(ctx context.Context, r subprocessRunner, gn, checkoutDir, buildDir string) (string, error) {
	cmd := []string{
	gn,
	"check",
	buildDir,
	fmt.Sprintf("--root=%s", checkoutDir),
	"--check-generated",
	"--check-system",
	}
	var stdoutBuf bytes.Buffer
	if err := r.Run(ctx, cmd, io.MultiWriter(&stdoutBuf, os.Stdout), os.Stderr); err != nil {
	return stdoutBuf.String(), fmt.Errorf("error running `gn check`: %w", err)
	}
	return stdoutBuf.String(), nil
	}