Merge "Ignore bazel-generated paths in dangling rule test"

ui/build/config.go

@@ -896,6 +896,10 @@ func (c *configImpl) BazelOutDir() string {
 	return filepath.Join(c.OutDir(), "bazel")
 }
 
+func (c *configImpl) bazelOutputBase() string {
+	return filepath.Join(c.BazelOutDir(), "output")
+}
+
 func (c *configImpl) SoongOutDir() string {
 	return filepath.Join(c.OutDir(), "soong")
 }

ui/build/soong.go

@@ -418,7 +418,7 @@ func runSoong(ctx Context, config Config) {
 	// Bazel's HOME var is set to an output subdirectory which doesn't exist. This
 	// prevents Bazel from file I/O in the actual user HOME directory.
 	soongBuildEnv.Set("BAZEL_HOME", absPath(ctx, filepath.Join(config.BazelOutDir(), "bazelhome")))
-	soongBuildEnv.Set("BAZEL_OUTPUT_BASE", filepath.Join(config.BazelOutDir(), "output"))
+	soongBuildEnv.Set("BAZEL_OUTPUT_BASE", config.bazelOutputBase())
 	soongBuildEnv.Set("BAZEL_WORKSPACE", absPath(ctx, "."))
 	soongBuildEnv.Set("BAZEL_METRICS_DIR", config.BazelMetricsDir())
 	soongBuildEnv.Set("LOG_DIR", config.LogsDir())

ui/build/test_build.go

@@ -18,14 +18,44 @@ import (
 	"bufio"
 	"fmt"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"sort"
 	"strings"
+	"sync"
 
 	"android/soong/ui/metrics"
 	"android/soong/ui/status"
 )
 
+var (
+	// bazel output paths are in __main__/bazel-out/<config-specific-path>/bin
+	bazelOutputPathRegexOnce sync.Once
+	bazelOutputPathRegexp    *regexp.Regexp
+)
+
+func bazelOutputPathPattern(config Config) *regexp.Regexp {
+	bazelOutputPathRegexOnce.Do(func() {
+		// Bazel output files are in <Bazel output base>/execroot/__main__/bazel-out/<config>/bin
+		bazelOutRoot := filepath.Join(regexp.QuoteMeta(config.bazelOutputBase()), "execroot", "__main__", "bazel-out")
+		bazelOutputPathRegexp = regexp.MustCompile(bazelOutRoot + "/[^/]+/bin")
+	})
+	return bazelOutputPathRegexp
+}
+
+func ignoreBazelPath(config Config, path string) bool {
+	bazelRoot := filepath.Join(config.bazelOutputBase(), "execroot")
+	// Don't check bazel output regexp unless it is Bazel path
+	if strings.HasPrefix(path, bazelRoot) {
+		bazelOutputRegexp := bazelOutputPathPattern(config)
+		// if the file is a bazel path that is _not_ a Bazel generated file output, we rely on Bazel to
+		// ensure the paths to exist. If it _is_ a Bazel output path, we expect that it should be built
+		// by Ninja.
+		return !bazelOutputRegexp.MatchString(path)
+	}
+	return false
+}
+
 // Checks for files in the out directory that have a rule that depends on them but no rule to
 // create them. This catches a common set of build failures where a rule to generate a file is
 // deleted (either by deleting a module in an Android.mk file, or by modifying the build system
@@ -97,6 +127,10 @@ func testForDanglingRules(ctx Context, config Config) {
 			// full build rules in the primary build.ninja file.
 			continue
 		}
+
+		if ignoreBazelPath(config, line) {
+			continue
+		}
 		danglingRules[line] = true
 	}