pkg/subsystem: restructure the package

Remove the entity and match subpackages.

Regenerate the linux.go file.

1 files changed, 68 insertions, 0 deletions

diff --git a/pkg/subsystem/linux/path_coincidence.go b/pkg/subsystem/linux/path_coincidence.go
new file mode 100644
index 000000000..44182bd6a
--- /dev/null
+++ b/pkg/subsystem/linux/path_coincidence.go
@@ -0,0 +1,68 @@
+// Copyright 2023 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package linux
+
+import (
+	"io/fs"
+	"regexp"
+	"runtime"
+	"sync"
+
+	"github.com/google/syzkaller/pkg/subsystem"
+)
+
+func BuildCoincidenceMatrix(root fs.FS, list []*subsystem.Subsystem,
+	excludeRe *regexp.Regexp) (*CoincidenceMatrix, error) {
+	// Create a matcher.
+	matcher := subsystem.MakePathMatcher(list)
+	chPaths, chResult := extractSubsystems(matcher)
+	// The final consumer goroutine.
+	cm := MakeCoincidenceMatrix()
+	ready := make(chan struct{})
+	go func() {
+		for items := range chResult {
+			cm.Record(items...)
+		}
+		ready <- struct{}{}
+	}()
+	// Source of data.
+	err := fs.WalkDir(root, ".", func(path string, info fs.DirEntry, err error) error {
+		if err != nil || info.IsDir() {
+			return err
+		}
+		if !includePathRe.MatchString(path) ||
+			(excludeRe != nil && excludeRe.MatchString(path)) {
+			return nil
+		}
+		chPaths <- path
+		return nil
+	})
+	close(chPaths)
+	<-ready
+	return cm, err
+}
+
+var (
+	includePathRe = regexp.MustCompile(`(?:/|\.(?:c|h|S))$`)
+)
+
+func extractSubsystems(matcher *subsystem.PathMatcher) (chan<- string, <-chan []*subsystem.Subsystem) {
+	procs := runtime.NumCPU()
+	paths, output := make(chan string, procs), make(chan []*subsystem.Subsystem, procs)
+	var wg sync.WaitGroup
+	for i := 0; i < procs; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for path := range paths {
+				output <- matcher.Match(path)
+			}
+		}()
+	}
+	go func() {
+		wg.Wait()
+		close(output)
+	}()
+	return paths, output
+}