Add --bazel-mode and --bazel-mode-dev

This allows "bazel mixed builds prod mode", in additional to reworking
the mechanism in which mixed builds dev mode is enabled.

As a followup, CI scripts will be migrated to use the new flags, as
USE_BAZEL_ANALYSIS=1 is deprecated.

Test: Manually ran --bazel-mode with an allowlist verifying that the
module alone was enabled
Test: Manually verified --bazel-mode and --bazel-mode-dev cause a build
failure

Change-Id: If0d34360e60452f428b05828f4ec7596b7cb619a
diff --git a/android/allowlists/allowlists.go b/android/allowlists/allowlists.go
index 5c79fa2..60b3503 100644
--- a/android/allowlists/allowlists.go
+++ b/android/allowlists/allowlists.go
@@ -595,4 +595,9 @@
 		"prebuilt_platform-robolectric-4.5.1-prebuilt",
 		"prebuilt_currysrc_org.eclipse",
 	}
+
+	ProdMixedBuildsEnabledList = []string{
+		// This list left intentionally empty for now. Add specific module names
+		// to have them built by Bazel in Prod Mixed Builds mode.
+	}
 )
diff --git a/android/bazel.go b/android/bazel.go
index 71eb036..3ae3d6f 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -219,16 +219,16 @@
 	// in the synthetic Bazel workspace.
 	keepExistingBuildFile map[string]bool
 
-	// Per-module allowlist to always opt modules in of both bp2build and mixed builds.
-	// These modules are usually in directories with many other modules that are not ready for
-	// conversion.
+	// Per-module allowlist to always opt modules into both bp2build and Bazel Dev Mode mixed
+	// builds. These modules are usually in directories with many other modules that are not ready
+	// for conversion.
 	//
 	// A module can either be in this list or its directory allowlisted entirely
 	// in bp2buildDefaultConfig, but not both at the same time.
 	moduleAlwaysConvert map[string]bool
 
-	// Per-module-type allowlist to always opt modules in to both bp2build and mixed builds
-	// when they have the same type as one listed.
+	// Per-module-type allowlist to always opt modules in to both bp2build and
+	// Bazel Dev Mode mixed builds when they have the same type as one listed.
 	moduleTypeAlwaysConvert map[string]bool
 
 	// Per-module denylist to always opt modules out of bp2build conversion.
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index d87f988..93b6779 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -343,7 +343,30 @@
 }
 
 func NewBazelContext(c *config) (BazelContext, error) {
-	if !c.IsMixedBuildsEnabled() {
+	var modulesDefaultToBazel bool
+	disabledModules := map[string]bool{}
+	enabledModules := map[string]bool{}
+
+	switch c.BuildMode {
+	case BazelProdMode:
+		modulesDefaultToBazel = false
+
+		for _, enabledProdModule := range allowlists.ProdMixedBuildsEnabledList {
+			enabledModules[enabledProdModule] = true
+		}
+	case BazelDevMode:
+		modulesDefaultToBazel = true
+
+		// Don't use partially-converted cc_library targets in mixed builds,
+		// since mixed builds would generally rely on both static and shared
+		// variants of a cc_library.
+		for staticOnlyModule, _ := range GetBp2BuildAllowList().ccLibraryStaticOnly {
+			disabledModules[staticOnlyModule] = true
+		}
+		for _, disabledDevModule := range allowlists.MixedBuildsDisabledList {
+			disabledModules[disabledDevModule] = true
+		}
+	default:
 		return noopBazelContext{}, nil
 	}
 
@@ -352,24 +375,12 @@
 		return nil, err
 	}
 
-	// TODO(cparsons): Use a different allowlist depending on prod vs. dev
-	// bazel mode.
-	disabledModules := map[string]bool{}
-	// Don't use partially-converted cc_library targets in mixed builds,
-	// since mixed builds would generally rely on both static and shared
-	// variants of a cc_library.
-	for staticOnlyModule, _ := range GetBp2BuildAllowList().ccLibraryStaticOnly {
-		disabledModules[staticOnlyModule] = true
-	}
-	for _, disabledDevModule := range allowlists.MixedBuildsDisabledList {
-		disabledModules[disabledDevModule] = true
-	}
-
 	return &bazelContext{
 		bazelRunner:           &builtinBazelRunner{},
 		paths:                 p,
 		requests:              make(map[cqueryKey]bool),
-		modulesDefaultToBazel: true,
+		modulesDefaultToBazel: modulesDefaultToBazel,
+		bazelEnabledModules:   enabledModules,
 		bazelDisabledModules:  disabledModules,
 	}, nil
 }
diff --git a/android/config.go b/android/config.go
index 5ca9420..222b142 100644
--- a/android/config.go
+++ b/android/config.go
@@ -96,7 +96,6 @@
 
 	// Use bazel during analysis of build modules from an allowlist carefully
 	// curated by the build team to be proven stable.
-	// TODO(cparsons): Implement this mode.
 	BazelProdMode
 )
 
@@ -481,14 +480,6 @@
 		config.AndroidFirstDeviceTarget = FirstTarget(config.Targets[Android], "lib64", "lib32")[0]
 	}
 
-	// Checking USE_BAZEL_ANALYSIS must be done here instead of in the caller, so
-	// that we can invoke IsEnvTrue (which also registers the env var as a
-	// dependency of the build).
-	// TODO(cparsons): Remove this hack once USE_BAZEL_ANALYSIS is removed.
-	if buildMode == AnalysisNoBazel && config.IsEnvTrue("USE_BAZEL_ANALYSIS") {
-		buildMode = BazelDevMode
-	}
-
 	config.BuildMode = buildMode
 	config.BazelContext, err = NewBazelContext(config)
 	config.bp2buildPackageConfig = GetBp2BuildAllowList()
@@ -678,9 +669,7 @@
 // DeviceProduct returns the current product target. There could be multiple of
 // these per device type.
 //
-// NOTE: Do not base conditional logic on this value. It may break product
-//
-//	inheritance.
+// NOTE: Do not base conditional logic on this value. It may break product inheritance.
 func (c *config) DeviceProduct() string {
 	return *c.productVariables.DeviceProduct
 }
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index 6930943..d15dea1 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -84,6 +84,8 @@
 	flag.StringVar(&bp2buildMarker, "bp2build_marker", "", "If set, run bp2build, touch the specified marker file then exit")
 	flag.StringVar(&cmdlineArgs.OutFile, "o", "build.ninja", "the Ninja file to output")
 	flag.BoolVar(&cmdlineArgs.EmptyNinjaFile, "empty-ninja-file", false, "write out a 0-byte ninja file")
+	flag.BoolVar(&cmdlineArgs.BazelMode, "bazel-mode", false, "use bazel for analysis of certain modules")
+	flag.BoolVar(&cmdlineArgs.BazelModeDev, "bazel-mode-dev", false, "use bazel for analysis of a large number of modules (less stable)")
 
 	// Flags that probably shouldn't be flags of soong_build but we haven't found
 	// the time to remove them yet
@@ -131,6 +133,10 @@
 		buildMode = android.GenerateModuleGraph
 	} else if docFile != "" {
 		buildMode = android.GenerateDocFile
+	} else if cmdlineArgs.BazelModeDev {
+		buildMode = android.BazelDevMode
+	} else if cmdlineArgs.BazelMode {
+		buildMode = android.BazelProdMode
 	} else {
 		buildMode = android.AnalysisNoBazel
 	}
diff --git a/ui/build/build.go b/ui/build/build.go
index f7a2d7b..c61baa1 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -110,6 +110,24 @@
 	RunAllWithBazel = RunProductConfig | RunSoong | RunKati | RunKatiNinja | RunBazel
 )
 
+// checkBazelMode fails the build if there are conflicting arguments for which bazel
+// build mode to use.
+func checkBazelMode(ctx Context, config Config) {
+	// TODO(cparsons): Remove USE_BAZEL_ANALYSIS handling.
+	if config.Environment().IsEnvTrue("USE_BAZEL_ANALYSIS") {
+		if config.bazelProdMode || config.bazelDevMode {
+			ctx.Fatalf("USE_BAZEL_ANALYSIS is deprecated.\n" +
+				"Unset USE_BAZEL_ANALYSIS when using --bazel-mode or --bazel-mode-dev.")
+		} else {
+			config.bazelDevMode = true
+		}
+	}
+	if config.bazelProdMode && config.bazelDevMode {
+		ctx.Fatalf("Conflicting bazel mode.\n" +
+			"Do not specify both --bazel-mode and --bazel-mode-dev")
+	}
+}
+
 // checkProblematicFiles fails the build if existing Android.mk or CleanSpec.mk files are found at the root of the tree.
 func checkProblematicFiles(ctx Context) {
 	files := []string{"Android.mk", "CleanSpec.mk"}
@@ -221,6 +239,8 @@
 
 	defer waitForDist(ctx)
 
+	checkBazelMode(ctx, config)
+
 	// checkProblematicFiles aborts the build if Android.mk or CleanSpec.mk are found at the root of the tree.
 	checkProblematicFiles(ctx)
 
diff --git a/ui/build/config.go b/ui/build/config.go
index e140867..590aeb9 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -99,7 +99,10 @@
 
 	pathReplaced bool
 
-	useBazel bool
+	// TODO(b/243077098): Remove useBazel.
+	useBazel      bool
+	bazelProdMode bool
+	bazelDevMode  bool
 
 	// During Bazel execution, Bazel cannot write outside OUT_DIR.
 	// So if DIST_DIR is set to an external dir (outside of OUT_DIR), we need to rig it temporarily and then migrate files at the end of the build.
@@ -130,18 +133,6 @@
 	BUILD_MODULES
 )
 
-type bazelBuildMode int
-
-// Bazel-related build modes.
-const (
-	// Don't use bazel at all.
-	noBazel bazelBuildMode = iota
-
-	// Generate synthetic build files and incorporate these files into a build which
-	// partially uses Bazel. Build metadata may come from Android.bp or BUILD files.
-	mixedBuild
-)
-
 // checkTopDir validates that the current directory is at the root directory of the source tree.
 func checkTopDir(ctx Context) {
 	if _, err := os.Stat(srcDirFileCheck); err != nil {
@@ -496,7 +487,7 @@
 		UseGoma:         proto.Bool(config.UseGoma()),
 		UseRbe:          proto.Bool(config.UseRBE()),
 		BazelAsNinja:    proto.Bool(config.UseBazel()),
-		BazelMixedBuild: proto.Bool(config.bazelBuildMode() == mixedBuild),
+		BazelMixedBuild: proto.Bool(config.BazelBuildEnabled()),
 	}
 	c.Targets = append(c.Targets, config.arguments...)
 
@@ -747,6 +738,10 @@
 			c.skipSoongTests = true
 		} else if arg == "--mk-metrics" {
 			c.reportMkMetrics = true
+		} else if arg == "--bazel-mode" {
+			c.bazelProdMode = true
+		} else if arg == "--bazel-mode-dev" {
+			c.bazelDevMode = true
 		} else if len(arg) > 0 && arg[0] == '-' {
 			parseArgNum := func(def int) int {
 				if len(arg) > 2 {
@@ -1134,16 +1129,13 @@
 	return false
 }
 
+// TODO(b/243077098): Remove UseBazel.
 func (c *configImpl) UseBazel() bool {
 	return c.useBazel
 }
 
-func (c *configImpl) bazelBuildMode() bazelBuildMode {
-	if c.Environment().IsEnvTrue("USE_BAZEL_ANALYSIS") {
-		return mixedBuild
-	} else {
-		return noBazel
-	}
+func (c *configImpl) BazelBuildEnabled() bool {
+	return c.bazelProdMode || c.bazelDevMode
 }
 
 func (c *configImpl) StartRBE() bool {
diff --git a/ui/build/config_test.go b/ui/build/config_test.go
index e293275..63716b0 100644
--- a/ui/build/config_test.go
+++ b/ui/build/config_test.go
@@ -28,6 +28,7 @@
 	"android/soong/ui/logger"
 	smpb "android/soong/ui/metrics/metrics_proto"
 	"android/soong/ui/status"
+	"google.golang.org/protobuf/encoding/prototext"
 
 	"google.golang.org/protobuf/proto"
 )
@@ -1005,6 +1006,8 @@
 		environ             Environment
 		arguments           []string
 		useBazel            bool
+		bazelDevMode        bool
+		bazelProdMode       bool
 		expectedBuildConfig *smpb.BuildConfig
 	}{
 		{
@@ -1064,7 +1067,7 @@
 			},
 		},
 		{
-			name:    "bazel mixed build",
+			name:    "bazel mixed build from env",
 			environ: Environment{"USE_BAZEL_ANALYSIS=1"},
 			expectedBuildConfig: &smpb.BuildConfig{
 				ForceUseGoma:    proto.Bool(false),
@@ -1075,6 +1078,30 @@
 			},
 		},
 		{
+			name:         "bazel mixed build from dev mode",
+			environ:      Environment{},
+			bazelDevMode: true,
+			expectedBuildConfig: &smpb.BuildConfig{
+				ForceUseGoma:    proto.Bool(false),
+				UseGoma:         proto.Bool(false),
+				UseRbe:          proto.Bool(false),
+				BazelAsNinja:    proto.Bool(false),
+				BazelMixedBuild: proto.Bool(true),
+			},
+		},
+		{
+			name:          "bazel mixed build from prod mode",
+			environ:       Environment{},
+			bazelProdMode: true,
+			expectedBuildConfig: &smpb.BuildConfig{
+				ForceUseGoma:    proto.Bool(false),
+				UseGoma:         proto.Bool(false),
+				UseRbe:          proto.Bool(false),
+				BazelAsNinja:    proto.Bool(false),
+				BazelMixedBuild: proto.Bool(true),
+			},
+		},
+		{
 			name:      "specified targets",
 			environ:   Environment{},
 			useBazel:  true,
@@ -1094,9 +1121,9 @@
 				"FORCE_USE_GOMA=1",
 				"USE_GOMA=1",
 				"USE_RBE=1",
-				"USE_BAZEL_ANALYSIS=1",
 			},
-			useBazel: true,
+			useBazel:     true,
+			bazelDevMode: true,
 			expectedBuildConfig: &smpb.BuildConfig{
 				ForceUseGoma:    proto.Bool(true),
 				UseGoma:         proto.Bool(true),
@@ -1107,17 +1134,23 @@
 		},
 	}
 
+	ctx := testContext()
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			c := &configImpl{
-				environ:   &tc.environ,
-				useBazel:  tc.useBazel,
-				arguments: tc.arguments,
+				environ:       &tc.environ,
+				useBazel:      tc.useBazel,
+				bazelDevMode:  tc.bazelDevMode,
+				bazelProdMode: tc.bazelProdMode,
+				arguments:     tc.arguments,
 			}
 			config := Config{c}
+			checkBazelMode(ctx, config)
 			actualBuildConfig := buildConfig(config)
 			if expected := tc.expectedBuildConfig; !proto.Equal(expected, actualBuildConfig) {
-				t.Errorf("Expected build config != actual build config: %#v != %#v", *expected, *actualBuildConfig)
+				t.Errorf("Build config mismatch.\n"+
+					"Expected build config: %#v\n"+
+					"Actual build config: %#v", prototext.Format(expected), prototext.Format(actualBuildConfig))
 			}
 		})
 	}
diff --git a/ui/build/soong.go b/ui/build/soong.go
index 3920ddd..2e94a46 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -254,6 +254,12 @@
 	if config.EmptyNinjaFile() {
 		mainSoongBuildExtraArgs = append(mainSoongBuildExtraArgs, "--empty-ninja-file")
 	}
+	if config.bazelProdMode {
+		mainSoongBuildExtraArgs = append(mainSoongBuildExtraArgs, "--bazel-mode")
+	}
+	if config.bazelDevMode {
+		mainSoongBuildExtraArgs = append(mainSoongBuildExtraArgs, "--bazel-mode-dev")
+	}
 
 	mainSoongBuildInvocation := primaryBuilderInvocation(
 		config,
@@ -263,7 +269,7 @@
 		fmt.Sprintf("analyzing Android.bp files and generating ninja file at %s", config.SoongNinjaFile()),
 	)
 
-	if config.bazelBuildMode() == mixedBuild {
+	if config.BazelBuildEnabled() {
 		// Mixed builds call Bazel from soong_build and they therefore need the
 		// Bazel workspace to be available. Make that so by adding a dependency on
 		// the bp2build marker file to the action that invokes soong_build .
@@ -373,9 +379,6 @@
 	// unused variables were changed?
 	envFile := filepath.Join(config.SoongOutDir(), availableEnvFile)
 
-	buildMode := config.bazelBuildMode()
-	integratedBp2Build := buildMode == mixedBuild
-
 	// This is done unconditionally, but does not take a measurable amount of time
 	bootstrapBlueprint(ctx, config)
 
@@ -405,7 +408,7 @@
 
 		checkEnvironmentFile(soongBuildEnv, config.UsedEnvFile(soongBuildTag))
 
-		if integratedBp2Build || config.Bp2Build() {
+		if config.BazelBuildEnabled() || config.Bp2Build() {
 			checkEnvironmentFile(soongBuildEnv, config.UsedEnvFile(bp2buildTag))
 		}