Initial implementation of the bazel sandwich

The "bazel sandwich" is a mechanism for bazel to depend on make/soong
outputs. The name comes from the fact that bazel is now at the top
and bottom of the build graph. This is intended to allow us to work
on converting the partition builds to bazel while not all of the
dependencies of the partition have been converted.

It works by adding the bazel_sandwich_import_file rule, which emits a
dangling symlink that starts with bazel_sandwich:, and includes
information that the aquery handler in soong reads. The aquery handler
rewrites the symlink so that it points to a file generated by
make/soong, and adds a ninja dependency from the symlink to the file
it's targeting.

This allows us to depend on make-built files from bazel, but notably
it doesn't allow us to depend on analysis-time information from make.
This shouldn't be a problem for the partitions, but limits the use of
the bazel sandwich to similar, less complicated types of builds.

go/roboleaf-bazel-sandwich

Bug: 265127181
Test: m bazel_sandwich
Change-Id: Ic41bae7be0b55f251d04a6a95f846c50ce897adc

android/allowlists/allowlists.go

@@ -1640,4 +1640,14 @@ var (
 		"art_":        DEFAULT_PRIORITIZED_WEIGHT,
 		"ndk_library": DEFAULT_PRIORITIZED_WEIGHT,
 	}
+
+	BazelSandwichTargets = []struct {
+		Label string
+		Host  bool
+	}{
+		{
+			Label: "//build/bazel/examples/partitions:system_image",
+			Host:  false,
+		},
+	}
 )

android/bazel_handler.go

@@ -186,6 +186,8 @@ type BazelContext interface {
 
 	// Returns the depsets defined in Bazel's aquery response.
 	AqueryDepsets() []bazel.AqueryDepset
+
+	QueueBazelSandwichCqueryRequests(config Config) error
 }
 
 type bazelRunner interface {
@@ -264,6 +266,10 @@ func (m MockBazelContext) QueueBazelRequest(label string, requestType cqueryRequ
 	m.BazelRequests[key] = true
 }
 
+func (m MockBazelContext) QueueBazelSandwichCqueryRequests(config Config) error {
+	panic("unimplemented")
+}
+
 func (m MockBazelContext) GetOutputFiles(label string, _ configKey) ([]string, error) {
 	result, ok := m.LabelToOutputFiles[label]
 	if !ok {
@@ -424,6 +430,10 @@ func (n noopBazelContext) QueueBazelRequest(_ string, _ cqueryRequest, _ configK
 	panic("unimplemented")
 }
 
+func (n noopBazelContext) QueueBazelSandwichCqueryRequests(config Config) error {
+	panic("unimplemented")
+}
+
 func (n noopBazelContext) GetOutputFiles(_ string, _ configKey) ([]string, error) {
 	panic("unimplemented")
 }
@@ -1042,6 +1052,45 @@ var (
 	allBazelCommands = []bazelCommand{aqueryCmd, cqueryCmd, buildCmd}
 )
 
+func GetBazelSandwichCqueryRequests(config Config) ([]cqueryKey, error) {
+	result := make([]cqueryKey, 0, len(allowlists.BazelSandwichTargets))
+	// Note that bazel "targets" are different from soong "targets", the bazel targets are
+	// synonymous with soong modules, and soong targets are a configuration a module is built in.
+	for _, target := range allowlists.BazelSandwichTargets {
+		var soongTarget Target
+		if target.Host {
+			soongTarget = config.BuildOSTarget
+		} else {
+			soongTarget = config.AndroidCommonTarget
+		}
+
+		result = append(result, cqueryKey{
+			label:       target.Label,
+			requestType: cquery.GetOutputFiles,
+			configKey: configKey{
+				arch:   soongTarget.Arch.String(),
+				osType: soongTarget.Os,
+			},
+		})
+	}
+	return result, nil
+}
+
+// QueueBazelSandwichCqueryRequests queues cquery requests for all the bazel labels in
+// bazel_sandwich_targets. These will later be given phony targets so that they can be built on the
+// command line.
+func (context *mixedBuildBazelContext) QueueBazelSandwichCqueryRequests(config Config) error {
+	requests, err := GetBazelSandwichCqueryRequests(config)
+	if err != nil {
+		return err
+	}
+	for _, request := range requests {
+		context.QueueBazelRequest(request.label, request.requestType, request.configKey)
+	}
+
+	return nil
+}
+
 // Issues commands to Bazel to receive results for all cquery requests
 // queued in the BazelContext.
 func (context *mixedBuildBazelContext) InvokeBazel(config Config, ctx invokeBazelContext) error {
@@ -1255,6 +1304,11 @@ func (c *bazelSingleton) GenerateBuildActions(ctx SingletonContext) {
 
 	executionRoot := path.Join(ctx.Config().BazelContext.OutputBase(), "execroot", "__main__")
 	bazelOutDir := path.Join(executionRoot, "bazel-out")
+	rel, err := filepath.Rel(ctx.Config().OutDir(), executionRoot)
+	if err != nil {
+		ctx.Errorf("%s", err.Error())
+	}
+	dotdotsToOutRoot := strings.Repeat("../", strings.Count(rel, "/")+1)
 	for index, buildStatement := range ctx.Config().BazelContext.BuildStatementsToRegister() {
 		// nil build statements are a valid case where we do not create an action because it is
 		// unnecessary or handled by other processing
@@ -1286,7 +1340,8 @@ func (c *bazelSingleton) GenerateBuildActions(ctx SingletonContext) {
 					})
 				}
 			}
-			createCommand(rule.Command(), buildStatement, executionRoot, bazelOutDir, ctx, depsetHashToDepset)
+			createCommand(rule.Command(), buildStatement, executionRoot, bazelOutDir, ctx, depsetHashToDepset, dotdotsToOutRoot)
+
 			desc := fmt.Sprintf("%s: %s", buildStatement.Mnemonic, buildStatement.OutputPaths)
 			rule.Build(fmt.Sprintf("bazel %d", index), desc)
 			continue
@@ -1331,6 +1386,24 @@ func (c *bazelSingleton) GenerateBuildActions(ctx SingletonContext) {
 			panic(fmt.Sprintf("unhandled build statement: %v", buildStatement))
 		}
 	}
+
+	// Create phony targets for all the bazel sandwich output files
+	requests, err := GetBazelSandwichCqueryRequests(ctx.Config())
+	if err != nil {
+		ctx.Errorf(err.Error())
+	}
+	for _, request := range requests {
+		files, err := ctx.Config().BazelContext.GetOutputFiles(request.label, request.configKey)
+		if err != nil {
+			ctx.Errorf(err.Error())
+		}
+		filesAsPaths := make([]Path, 0, len(files))
+		for _, file := range files {
+			filesAsPaths = append(filesAsPaths, PathForBazelOut(ctx, file))
+		}
+		ctx.Phony("bazel_sandwich", filesAsPaths...)
+	}
+	ctx.Phony("checkbuild", PathForPhony(ctx, "bazel_sandwich"))
 }
 
 // Returns a out dir path for a sandboxed mixed build action
@@ -1344,7 +1417,7 @@ func intermediatePathForSboxMixedBuildAction(ctx PathContext, statement *bazel.B
 }
 
 // Register bazel-owned build statements (obtained from the aquery invocation).
-func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement, executionRoot string, bazelOutDir string, ctx BuilderContext, depsetHashToDepset map[string]bazel.AqueryDepset) {
+func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement, executionRoot string, bazelOutDir string, ctx BuilderContext, depsetHashToDepset map[string]bazel.AqueryDepset, dotdotsToOutRoot string) {
 	// executionRoot is the action cwd.
 	if buildStatement.ShouldRunInSbox {
 		// mkdir -p ensures that the directory exists when run via sbox
@@ -1367,14 +1440,17 @@ func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement
 		cmd.Flag(pair.Key + "=" + pair.Value)
 	}
 
+	command := buildStatement.Command
+	command = strings.ReplaceAll(command, "{DOTDOTS_TO_OUTPUT_ROOT}", dotdotsToOutRoot)
+
 	// The actual Bazel action.
-	if len(buildStatement.Command) > 16*1024 {
+	if len(command) > 16*1024 {
 		commandFile := PathForBazelOut(ctx, buildStatement.OutputPaths[0]+".sh")
-		WriteFileRule(ctx, commandFile, buildStatement.Command)
+		WriteFileRule(ctx, commandFile, command)
 
 		cmd.Text("bash").Text(buildStatement.OutputPaths[0] + ".sh").Implicit(commandFile)
 	} else {
-		cmd.Text(buildStatement.Command)
+		cmd.Text(command)
 	}
 
 	for _, outputPath := range buildStatement.OutputPaths {
@@ -1403,6 +1479,9 @@ func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement
 			cmd.Implicit(PathForPhony(ctx, otherDepsetName))
 		}
 	}
+	for _, implicitPath := range buildStatement.ImplicitDeps {
+		cmd.Implicit(PathForArbitraryOutput(ctx, implicitPath))
+	}
 
 	if depfile := buildStatement.Depfile; depfile != nil {
 		// The paths in depfile are relative to `executionRoot`.

android/bazel_handler_test.go

@@ -181,7 +181,7 @@ func TestInvokeBazelPopulatesBuildStatements(t *testing.T) {
 
 		cmd := RuleBuilderCommand{}
 		ctx := builderContextForTests{PathContextForTesting(TestConfig("out", nil, "", nil))}
-		createCommand(&cmd, got[0], "test/exec_root", "test/bazel_out", ctx, map[string]bazel.AqueryDepset{})
+		createCommand(&cmd, got[0], "test/exec_root", "test/bazel_out", ctx, map[string]bazel.AqueryDepset{}, "")
 		if actual, expected := cmd.buf.String(), testCase.command; expected != actual {
 			t.Errorf("expected: [%s], actual: [%s]", expected, actual)
 		}
@@ -224,7 +224,7 @@ func TestMixedBuildSandboxedAction(t *testing.T) {
 
 	cmd := RuleBuilderCommand{}
 	ctx := builderContextForTests{PathContextForTesting(TestConfig("out", nil, "", nil))}
-	createCommand(&cmd, statement, "test/exec_root", "test/bazel_out", ctx, map[string]bazel.AqueryDepset{})
+	createCommand(&cmd, statement, "test/exec_root", "test/bazel_out", ctx, map[string]bazel.AqueryDepset{}, "")
 	// Assert that the output is generated in an intermediate directory
 	// fe05bcdcdc4928012781a5f1a2a77cbb5398e106 is the sha1 checksum of "one"
 	if actual, expected := cmd.outputs[0].String(), "out/soong/mixed_build_sbox_intermediates/fe05bcdcdc4928012781a5f1a2a77cbb5398e106/test/exec_root/one"; expected != actual {

android/paths.go

@@ -1029,16 +1029,16 @@ func (p basePath) withRel(rel string) basePath {
 	return p
 }
 
+func (p basePath) RelativeToTop() Path {
+	ensureTestOnly()
+	return p
+}
+
 // SourcePath is a Path representing a file path rooted from SrcDir
 type SourcePath struct {
 	basePath
 }
 
-func (p SourcePath) RelativeToTop() Path {
-	ensureTestOnly()
-	return p
-}
-
 var _ Path = SourcePath{}
 
 func (p SourcePath) withRel(rel string) SourcePath {
@@ -1126,6 +1126,16 @@ func PathForSource(ctx PathContext, pathComponents ...string) SourcePath {
 	return path
 }
 
+// PathForArbitraryOutput creates a path for the given components. Unlike PathForOutput,
+// the path is relative to the root of the output folder, not the out/soong folder.
+func PathForArbitraryOutput(ctx PathContext, pathComponents ...string) Path {
+	p, err := validatePath(pathComponents...)
+	if err != nil {
+		reportPathError(ctx, err)
+	}
+	return basePath{path: filepath.Join(ctx.Config().OutDir(), p)}
+}
+
 // MaybeExistentPathForSource joins the provided path components and validates that the result
 // neither escapes the source dir nor is in the out dir.
 // It does not validate whether the path exists.

bazel/aquery.go

@@ -17,15 +17,15 @@ package bazel
 import (
 	"crypto/sha256"
 	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"path/filepath"
+	analysis_v2_proto "prebuilts/bazel/common/proto/analysis_v2"
 	"reflect"
 	"sort"
 	"strings"
 	"sync"
 
-	analysis_v2_proto "prebuilts/bazel/common/proto/analysis_v2"
-
 	"github.com/google/blueprint/metrics"
 	"github.com/google/blueprint/proptools"
 	"google.golang.org/protobuf/proto"
@@ -119,6 +119,10 @@ type BuildStatement struct {
 	// If ShouldRunInSbox is true, Soong will use sbox to created an isolated environment
 	// and run the mixed build action there
 	ShouldRunInSbox bool
+	// A list of files to add as implicit deps to the outputs of this BuildStatement.
+	// Unlike most properties in BuildStatement, these paths must be relative to the root of
+	// the whole out/ folder, instead of relative to ctx.Config().BazelContext.OutputBase()
+	ImplicitDeps []string
 }
 
 // A helper type for aquery processing which facilitates retrieval of path IDs from their
@@ -581,6 +585,72 @@ func (a *aqueryArtifactHandler) symlinkTreeActionBuildStatement(actionEntry *ana
 	}, nil
 }
 
+type bazelSandwichJson struct {
+	Target         string   `json:"target"`
+	DependOnTarget *bool    `json:"depend_on_target,omitempty"`
+	ImplicitDeps   []string `json:"implicit_deps"`
+}
+
+func (a *aqueryArtifactHandler) unresolvedSymlinkActionBuildStatement(actionEntry *analysis_v2_proto.Action) (*BuildStatement, error) {
+	outputPaths, depfile, err := a.getOutputPaths(actionEntry)
+	if err != nil {
+		return nil, err
+	}
+	if len(actionEntry.InputDepSetIds) != 0 || len(outputPaths) != 1 {
+		return nil, fmt.Errorf("expected 0 inputs and 1 output to symlink action, got: input %q, output %q", actionEntry.InputDepSetIds, outputPaths)
+	}
+	target := actionEntry.UnresolvedSymlinkTarget
+	if target == "" {
+		return nil, fmt.Errorf("expected an unresolved_symlink_target, but didn't get one")
+	}
+	if filepath.Clean(target) != target {
+		return nil, fmt.Errorf("expected %q, got %q", filepath.Clean(target), target)
+	}
+	if strings.HasPrefix(target, "/") {
+		return nil, fmt.Errorf("no absolute symlinks allowed: %s", target)
+	}
+
+	out := outputPaths[0]
+	outDir := filepath.Dir(out)
+	var implicitDeps []string
+	if strings.HasPrefix(target, "bazel_sandwich:") {
+		j := bazelSandwichJson{}
+		err := json.Unmarshal([]byte(target[len("bazel_sandwich:"):]), &j)
+		if err != nil {
+			return nil, err
+		}
+		if proptools.BoolDefault(j.DependOnTarget, true) {
+			implicitDeps = append(implicitDeps, j.Target)
+		}
+		implicitDeps = append(implicitDeps, j.ImplicitDeps...)
+		dotDotsToReachCwd := ""
+		if outDir != "." {
+			dotDotsToReachCwd = strings.Repeat("../", strings.Count(outDir, "/")+1)
+		}
+		target = proptools.ShellEscapeIncludingSpaces(j.Target)
+		target = "{DOTDOTS_TO_OUTPUT_ROOT}" + dotDotsToReachCwd + target
+	} else {
+		target = proptools.ShellEscapeIncludingSpaces(target)
+	}
+
+	outDir = proptools.ShellEscapeIncludingSpaces(outDir)
+	out = proptools.ShellEscapeIncludingSpaces(out)
+	// Use absolute paths, because some soong actions don't play well with relative paths (for example, `cp -d`).
+	command := fmt.Sprintf("mkdir -p %[1]s && rm -f %[2]s && ln -sf %[3]s %[2]s", outDir, out, target)
+	symlinkPaths := outputPaths[:]
+
+	buildStatement := &BuildStatement{
+		Command:      command,
+		Depfile:      depfile,
+		OutputPaths:  outputPaths,
+		Env:          actionEntry.EnvironmentVariables,
+		Mnemonic:     actionEntry.Mnemonic,
+		SymlinkPaths: symlinkPaths,
+		ImplicitDeps: implicitDeps,
+	}
+	return buildStatement, nil
+}
+
 func (a *aqueryArtifactHandler) symlinkActionBuildStatement(actionEntry *analysis_v2_proto.Action) (*BuildStatement, error) {
 	outputPaths, depfile, err := a.getOutputPaths(actionEntry)
 	if err != nil {
@@ -690,6 +760,8 @@ func (a *aqueryArtifactHandler) actionToBuildStatement(actionEntry *analysis_v2_
 		return a.fileWriteActionBuildStatement(actionEntry)
 	case "SymlinkTree":
 		return a.symlinkTreeActionBuildStatement(actionEntry)
+	case "UnresolvedSymlink":
+		return a.unresolvedSymlinkActionBuildStatement(actionEntry)
 	}
 
 	if len(actionEntry.Arguments) < 1 {

bazel/aquery_test.go

@@ -357,9 +357,11 @@ func TestDepfiles(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 	if expected := 1; len(actual) != expected {
 		t.Fatalf("Expected %d build statements, got %d", expected, len(actual))
+		return
 	}
 
 	bs := actual[0]
@@ -544,6 +546,7 @@ func TestSymlinkTree(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 	assertBuildStatements(t, []*BuildStatement{
 		&BuildStatement{
@@ -756,9 +759,11 @@ func TestMiddlemenAction(t *testing.T) {
 	actualBuildStatements, actualDepsets, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 	if expected := 2; len(actualBuildStatements) != expected {
 		t.Fatalf("Expected %d build statements, got %d %#v", expected, len(actualBuildStatements), actualBuildStatements)
+		return
 	}
 
 	expectedDepsetFiles := [][]string{
@@ -859,6 +864,7 @@ func TestSimpleSymlink(t *testing.T) {
 
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 
 	expectedBuildStatements := []*BuildStatement{
@@ -907,6 +913,7 @@ func TestSymlinkQuotesPaths(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 
 	expectedBuildStatements := []*BuildStatement{
@@ -1017,6 +1024,7 @@ func TestTemplateExpandActionSubstitutions(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 
 	expectedBuildStatements := []*BuildStatement{
@@ -1088,6 +1096,7 @@ func TestFileWrite(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 	assertBuildStatements(t, []*BuildStatement{
 		&BuildStatement{
@@ -1126,6 +1135,7 @@ func TestSourceSymlinkManifest(t *testing.T) {
 	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
 	if err != nil {
 		t.Errorf("Unexpected error %q", err)
+		return
 	}
 	assertBuildStatements(t, []*BuildStatement{
 		&BuildStatement{
@@ -1136,6 +1146,126 @@ func TestSourceSymlinkManifest(t *testing.T) {
 	}, actual)
 }
 
+func TestUnresolvedSymlink(t *testing.T) {
+	const inputString = `
+{
+ "artifacts": [
+   { "id": 1, "path_fragment_id": 1 }
+ ],
+ "actions": [{
+   "target_id": 1,
+   "action_key": "x",
+   "mnemonic": "UnresolvedSymlink",
+   "configuration_id": 1,
+   "output_ids": [1],
+   "primary_output_id": 1,
+   "execution_platform": "//build/bazel/platforms:linux_x86_64",
+   "unresolved_symlink_target": "symlink/target"
+ }],
+ "path_fragments": [
+   { "id": 1, "label": "path/to/symlink" }
+ ]
+}
+`
+	data, err := JsonToActionGraphContainer(inputString)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+		return
+	}
+	assertBuildStatements(t, []*BuildStatement{{
+		Command:      "mkdir -p path/to && rm -f path/to/symlink && ln -sf symlink/target path/to/symlink",
+		OutputPaths:  []string{"path/to/symlink"},
+		Mnemonic:     "UnresolvedSymlink",
+		SymlinkPaths: []string{"path/to/symlink"},
+	}}, actual)
+}
+
+func TestUnresolvedSymlinkBazelSandwich(t *testing.T) {
+	const inputString = `
+{
+ "artifacts": [
+   { "id": 1, "path_fragment_id": 1 }
+ ],
+ "actions": [{
+   "target_id": 1,
+   "action_key": "x",
+   "mnemonic": "UnresolvedSymlink",
+   "configuration_id": 1,
+   "output_ids": [1],
+   "primary_output_id": 1,
+   "execution_platform": "//build/bazel/platforms:linux_x86_64",
+   "unresolved_symlink_target": "bazel_sandwich:{\"target\":\"target/product/emulator_x86_64/system\"}"
+ }],
+ "path_fragments": [
+   { "id": 1, "label": "path/to/symlink" }
+ ]
+}
+`
+	data, err := JsonToActionGraphContainer(inputString)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+		return
+	}
+	assertBuildStatements(t, []*BuildStatement{{
+		Command:      "mkdir -p path/to && rm -f path/to/symlink && ln -sf {DOTDOTS_TO_OUTPUT_ROOT}../../target/product/emulator_x86_64/system path/to/symlink",
+		OutputPaths:  []string{"path/to/symlink"},
+		Mnemonic:     "UnresolvedSymlink",
+		SymlinkPaths: []string{"path/to/symlink"},
+		ImplicitDeps: []string{"target/product/emulator_x86_64/system"},
+	}}, actual)
+}
+
+func TestUnresolvedSymlinkBazelSandwichWithAlternativeDeps(t *testing.T) {
+	const inputString = `
+{
+ "artifacts": [
+   { "id": 1, "path_fragment_id": 1 }
+ ],
+ "actions": [{
+   "target_id": 1,
+   "action_key": "x",
+   "mnemonic": "UnresolvedSymlink",
+   "configuration_id": 1,
+   "output_ids": [1],
+   "primary_output_id": 1,
+   "execution_platform": "//build/bazel/platforms:linux_x86_64",
+   "unresolved_symlink_target": "bazel_sandwich:{\"depend_on_target\":false,\"implicit_deps\":[\"target/product/emulator_x86_64/obj/PACKAGING/systemimage_intermediates/staging_dir.stamp\"],\"target\":\"target/product/emulator_x86_64/system\"}"
+ }],
+ "path_fragments": [
+   { "id": 1, "label": "path/to/symlink" }
+ ]
+}
+`
+	data, err := JsonToActionGraphContainer(inputString)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	actual, _, err := AqueryBuildStatements(data, &metrics.EventHandler{})
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+		return
+	}
+	assertBuildStatements(t, []*BuildStatement{{
+		Command:      "mkdir -p path/to && rm -f path/to/symlink && ln -sf {DOTDOTS_TO_OUTPUT_ROOT}../../target/product/emulator_x86_64/system path/to/symlink",
+		OutputPaths:  []string{"path/to/symlink"},
+		Mnemonic:     "UnresolvedSymlink",
+		SymlinkPaths: []string{"path/to/symlink"},
+		// Note that the target of the symlink, target/product/emulator_x86_64/system, is not listed here
+		ImplicitDeps: []string{"target/product/emulator_x86_64/obj/PACKAGING/systemimage_intermediates/staging_dir.stamp"},
+	}}, actual)
+}
+
 func assertError(t *testing.T, err error, expected string) {
 	t.Helper()
 	if err == nil {
@@ -1201,6 +1331,9 @@ func buildStatementEquals(first *BuildStatement, second *BuildStatement) string
 	if !reflect.DeepEqual(sortedStrings(first.SymlinkPaths), sortedStrings(second.SymlinkPaths)) {
 		return "SymlinkPaths"
 	}
+	if !reflect.DeepEqual(sortedStrings(first.ImplicitDeps), sortedStrings(second.ImplicitDeps)) {
+		return "ImplicitDeps"
+	}
 	if first.Depfile != second.Depfile {
 		return "Depfile"
 	}

bp2build/bp2build_product_config.go

@@ -97,6 +97,7 @@ load("@//build/bazel/product_config:android_product.bzl", "android_product")
 android_product(
     name = "mixed_builds_product-{VARIANT}",
     soong_variables = _soong_variables,
+    extra_constraints = ["@//build/bazel/platforms:mixed_builds"],
 )
 `)),
 		newFile(

cmd/soong_build/main.go

@@ -121,6 +121,10 @@ func runMixedModeBuild(ctx *android.Context, extraNinjaDeps []string) string {
 	defer ctx.EventHandler.End("mixed_build")
 
 	bazelHook := func() error {
+		err := ctx.Config().BazelContext.QueueBazelSandwichCqueryRequests(ctx.Config())
+		if err != nil {
+			return err
+		}
 		return ctx.Config().BazelContext.InvokeBazel(ctx.Config(), ctx)
 	}
 	ctx.SetBeforePrepareBuildActionsHook(bazelHook)