Add groundwork to easily all-enable bazel-mode

This will make it easy to change a "false" boolean to "true" to push
`--bazel-mode` by default for all users.

Users may disable bazel-by-default with BUILD_BROKEN_DISABLE_BAZEL, and
bazel is disabled by default on Darwin hosts (due to lack of test
coverage).

Bug: 254628592
Bug: 254084584
Test: Presubmits
Test: Presubmits for aosp/2263623
Change-Id: Iec712119e06ca8ec93028207d88277f879184cc2

tests/bootstrap_test.sh

@@ -547,7 +547,6 @@ function test_bp2build_smoke {
 
 function test_bp2build_generates_marker_file {
   setup
-  create_mock_bazel
 
   run_soong bp2build
 

tests/bp2build_bazel_test.sh

@@ -50,7 +50,6 @@ test_bp2build_null_build_with_globs
 
 function test_different_relative_outdir {
   setup
-  create_mock_bazel
 
   mkdir -p a
   touch a/g.txt
@@ -73,7 +72,6 @@ test_different_relative_outdir
 
 function test_different_absolute_outdir {
   setup
-  create_mock_bazel
 
   mkdir -p a
   touch a/g.txt
@@ -96,7 +94,6 @@ test_different_absolute_outdir
 
 function test_bp2build_generates_all_buildfiles {
   setup
-  create_mock_bazel
 
   mkdir -p foo/convertible_soong_module
   cat > foo/convertible_soong_module/Android.bp <<'EOF'
@@ -167,7 +164,6 @@ eval ${_save_trap}
 
 function test_cc_correctness {
   setup
-  create_mock_bazel
 
   mkdir -p a
   cat > a/Android.bp <<EOF

tests/lib.sh

@@ -82,10 +82,10 @@ function symlink_directory {
 }
 
 function create_mock_soong {
+  create_mock_bazel
   copy_directory build/blueprint
   copy_directory build/soong
   copy_directory build/make/tools/rbcrun
-  copy_directory prebuilts/bazel/common/proto
 
   symlink_directory prebuilts/sdk
   symlink_directory prebuilts/go

tests/mixed_mode_test.sh

@@ -12,7 +12,6 @@ source "$(dirname "$0")/lib.sh"
 
 function test_bazel_smoke {
   setup
-  create_mock_bazel
 
   run_soong bp2build
 
@@ -21,7 +20,6 @@ function test_bazel_smoke {
 
 function test_add_irrelevant_file {
   setup
-  create_mock_bazel
 
   mkdir -p soong_tests/a/b
   touch soong_tests/a/b/c.txt
@@ -33,7 +31,7 @@ filegroup {
 }
 EOF
 
-  run_soong --bazel-mode nothing
+  run_soong --bazel-mode-staging nothing
 
   if [[ ! -e out/soong/bp2build/soong_tests/a/b/BUILD.bazel ]]; then
     fail "BUILD.bazel not created"
@@ -48,7 +46,7 @@ EOF
 
   touch soong_tests/a/irrelevant.txt
 
-  run_soong --bazel-mode nothing
+  run_soong --bazel-mode-staging nothing
   local mtime_build2=$(stat -c "%y" out/soong/bp2build/soong_tests/a/b/BUILD.bazel)
   local mtime_ninja2=$(stat -c "%y" out/soong/build.ninja)
 

ui/build/config.go

@@ -236,6 +236,21 @@ func loadEnvConfig(ctx Context, config *configImpl) error {
 	return nil
 }
 
+func defaultBazelProdMode(cfg *configImpl) bool {
+	// Envirnoment flag to disable Bazel for users which experience
+	// broken bazel-handled builds, or significant performance regressions.
+	if cfg.IsBazelMixedBuildForceDisabled() {
+		return false
+	}
+	// Darwin-host builds are currently untested with Bazel.
+	if runtime.GOOS == "darwin" {
+		return false
+	}
+	// TODO(b/255364055): Flip this to true to enable bazel-mode by default
+	// for all users that don't opt out with BUILD_BROKEN_DISABLE_BAZEL.
+	return false
+}
+
 func NewConfig(ctx Context, args ...string) Config {
 	ret := &configImpl{
 		environ:       OsEnvironment(),
@@ -774,6 +789,9 @@ func (c *configImpl) parseArgs(ctx Context, args []string) {
 			c.arguments = append(c.arguments, arg)
 		}
 	}
+	if (!c.bazelProdMode) && (!c.bazelDevMode) && (!c.bazelStagingMode) {
+		c.bazelProdMode = defaultBazelProdMode(c)
+	}
 }
 
 func (c *configImpl) configureLocale(ctx Context) {

ui/build/config_test.go

@@ -90,7 +90,9 @@ func TestConfigParseArgsJK(t *testing.T) {
 				t.Fatal(err)
 			})
 
+			env := Environment([]string{})
 			c := &configImpl{
+				environ:   &env,
 				parallel:  -1,
 				keepGoing: -1,
 			}