Revert^2 "Initial implementation of the bazel sandwich"

c13fad8181c9df93bf63462309da2f488f374c7c

Change-Id: I478562c8fd89e62983feb5b52b62aad851d40f00
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index 94bc88b..fd4b5ef 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -186,6 +186,8 @@
 
 	// Returns the depsets defined in Bazel's aquery response.
 	AqueryDepsets() []bazel.AqueryDepset
+
+	QueueBazelSandwichCqueryRequests(config Config) error
 }
 
 type bazelRunner interface {
@@ -264,6 +266,10 @@
 	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 @@
 	panic("unimplemented")
 }
 
+func (n noopBazelContext) QueueBazelSandwichCqueryRequests(config Config) error {
+	panic("unimplemented")
+}
+
 func (n noopBazelContext) GetOutputFiles(_ string, _ configKey) ([]string, error) {
 	panic("unimplemented")
 }
@@ -1042,6 +1052,50 @@
 	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
+			if soongTarget.Os.Class != Device {
+				// kernel-build-tools seems to set the AndroidCommonTarget to a linux host
+				// target for some reason, disable device builds in that case.
+				continue
+			}
+		}
+
+		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 +1309,11 @@
 
 	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 +1345,8 @@
 					})
 				}
 			}
-			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 +1391,24 @@
 			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 +1422,7 @@
 }
 
 // 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 +1445,17 @@
 		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 +1484,9 @@
 			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`.