Merge "soong_ui's bazel.go: document/comment with tiny refactoring."

	"android/soong/ui/metrics"

)

// Main entry point to construct the Bazel build command line, environment variables

// and post-processing steps (e.g. converge output directories)

// Main entry point to construct the Bazel build command line, environment

// variables and post-processing steps (e.g. converge output directories)

func runBazel(ctx Context, config Config) {

	ctx.BeginTrace(metrics.RunBazel, "bazel")

	defer ctx.EndTrace()

		outputGroups = strings.Join(config.ninjaArgs, ",")

	}

	// Environment variables are the primary mechanism to pass information from

	// soong_ui configuration or context to Bazel.

	//

	// Use *_NINJA variables to pass the root-relative path of the combined,

	// kati-generated, soong-generated, and packaging Ninja files to Bazel.

	// Bazel reads these from the lunch() repository rule.

	config.environ.Set("COMBINED_NINJA", config.CombinedNinjaFile())

	config.environ.Set("KATI_NINJA", config.KatiBuildNinjaFile())

	config.environ.Set("PACKAGE_NINJA", config.KatiPackageNinjaFile())

	config.environ.Set("SOONG_NINJA", config.SoongNinjaFile())

	// `tools/bazel` is the default entry point for executing Bazel in the AOSP

	// source tree.

	bazelExecutable := filepath.Join("tools", "bazel")

	cmd := Command(ctx, config, "bazel", bazelExecutable)

	if extra_startup_args, ok := cmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {

		cmd.Args = append(cmd.Args, strings.Fields(extra_startup_args)...)

	// Append custom startup flags to the Bazel command. Startup flags affect

	// the Bazel server itself, and any changes to these flags would incur a

	// restart of the server, losing much of the in-memory incrementality.

	if extraStartupArgs, ok := cmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {

		cmd.Args = append(cmd.Args, strings.Fields(extraStartupArgs)...)

	}

	// Start constructing the `build` command.

	actionName := "build"

	cmd.Args = append(cmd.Args,

		actionName,

		// Use output_groups to select the set of outputs to produce from a

		// ninja_build target.

		"--output_groups="+outputGroups,

		// Generate a performance profile

		"--profile="+filepath.Join(shared.BazelMetricsFilename(config.OutDir(), actionName)),

		"--slim_profile=true",

	)

	if extra_build_args, ok := cmd.Environment.Get("BAZEL_BUILD_ARGS"); ok {

		cmd.Args = append(cmd.Args, strings.Fields(extra_build_args)...)

	// Append custom build flags to the Bazel command. Changes to these flags

	// may invalidate Bazel's analysis cache.

	if extraBuildArgs, ok := cmd.Environment.Get("BAZEL_BUILD_ARGS"); ok {

		cmd.Args = append(cmd.Args, strings.Fields(extraBuildArgs)...)

	}

	// Append the label of the default ninja_build target.

	cmd.Args = append(cmd.Args,

		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),

	)

	// Ensure that the PATH environment variable value used in the action

	// environment is the restricted set computed from soong_ui, and not a

	// user-provided one, for hermeticity reasons.

	if pathEnvValue, ok := config.environ.Get("PATH"); ok {

		cmd.Environment.Set("PATH", pathEnvValue)

		cmd.Args = append(cmd.Args, "--action_env=PATH="+pathEnvValue)

	}

	cmd.Environment.Set("DIST_DIR", config.DistDir())

	cmd.Environment.Set("SHELL", "/bin/bash")

	// Print the full command line for debugging purposes.

	ctx.Println(cmd.Cmd)

	// Execute the command at the root of the directory.

	cmd.Dir = filepath.Join(config.OutDir(), "..")

	ctx.Status.Status("Starting Bazel..")

	// Execute the build command.

	cmd.RunAndStreamOrFatal()

	// Post-processing steps start here. Once the Bazel build completes, the

	// output files are still stored in the execution root, not in $OUT_DIR.

	// Ensure that the $OUT_DIR contains the expected set of files by symlinking

	// the files from the execution root's output direction into $OUT_DIR.

	// Obtain the Bazel output directory for ninja_build.

	infoCmd := Command(ctx, config, "bazel", bazelExecutable)

	if extra_startup_args, ok := infoCmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {

		infoCmd.Args = append(infoCmd.Args, strings.Fields(extra_startup_args)...)

	if extraStartupArgs, ok := infoCmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {

		infoCmd.Args = append(infoCmd.Args, strings.Fields(extraStartupArgs)...)

	}

	// Obtain the output directory path in the execution root.

	infoCmd.Args = append(infoCmd.Args,

		"info",

		"output_path",