Extract IsInterestingExecutable from gobinary's FileRequired

PiperOrigin-RevId: 713069569

extractor/filesystem/filesystem.go

@@ -538,3 +538,22 @@ func (i *ScanInput) GetRealPath() (string, error) {
 	io.Copy(f, i.Reader)
 	return path, nil
 }
+
+// IsInterestingExecutable returns true if the specified file is an executable which may need scanning.
+func IsInterestingExecutable(path string, fileInfo fs.FileInfo) bool {
+	// TODO(b/380419487): This is inefficient, it would be better to filter out common
+	// non executables by their file extension.
+
+	// Ignore non regular files such as dirs, symlinks, sockets, pipes, etc....
+	if !fileInfo.Mode().IsRegular() {
+		return false
+	}
+
+	// TODO(b/279138598): Research: Maybe on windows all files have the executable bit set.
+	// Either windows .exe or unix executable bit should be set.
+	if filepath.Ext(path) != ".exe" && fileInfo.Mode()&0111 == 0 {
+		return false
+	}
+
+	return true
+}

extractor/filesystem/filesystem_test.go

@@ -39,6 +39,7 @@ import (
 	"github.com/google/osv-scalibr/plugin"
 	"github.com/google/osv-scalibr/stats"
 	fe "github.com/google/osv-scalibr/testing/fakeextractor"
+	"github.com/google/osv-scalibr/testing/fakefs"
 )
 
 // pathsMapFS provides a hooked version of MapFS that forces slashes. Because depending on the
@@ -713,3 +714,66 @@ func TestRunFS_ReadError(t *testing.T) {
 		t.Errorf("extractor.Run(%v): unexpected status (-want +got):\n%s", ex, diff)
 	}
 }
+
+func TestIsInterestingExecutable(t *testing.T) {
+	tests := []struct {
+		name string
+		path string
+		mode fs.FileMode
+		want bool
+	}{
+		{
+			name: "user executable",
+			path: "some/path/a",
+			mode: 0766,
+			want: true,
+		},
+		{
+			name: "group executable",
+			path: "some/path/a",
+			mode: 0676,
+			want: true,
+		},
+		{
+			name: "other executable",
+			path: "some/path/a",
+			mode: 0667,
+			want: true,
+		},
+		{
+			name: "windows exe",
+			path: "some/path/a.exe",
+			mode: 0666,
+			want: true,
+		},
+		{
+			name: "not executable bit set",
+			path: "some/path/a",
+			mode: 0640,
+			want: false,
+		},
+		{
+			name: "Non regular file, socket",
+			path: "some/path/a",
+			mode: fs.ModeSocket | 0777,
+			want: false,
+		},
+		{
+			name: "executable required",
+			path: "some/path/a",
+			mode: 0766,
+			want: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := filesystem.IsInterestingExecutable(tt.path, fakefs.FakeFileInfo{
+				FileName: filepath.Base(tt.path),
+				FileMode: tt.mode,
+			}); got != tt.want {
+				t.Fatalf("FileRequired(%s): got %v, want %v", tt.path, got, tt.want)
+			}
+		})
+	}
+}

extractor/filesystem/language/golang/gobinary/gobinary.go

@@ -22,7 +22,6 @@ import (
 	"errors"
 	"io"
 	"io/fs"
-	"path/filepath"
 	"runtime/debug"
 	"strings"
 
@@ -96,14 +95,7 @@ func (e Extractor) FileRequired(api filesystem.FileAPI) bool {
 		return false
 	}
 
-	if !fileinfo.Mode().IsRegular() {
-		// Includes dirs, symlinks, sockets, pipes...
-		return false
-	}
-
-	// TODO(b/279138598): Research: Maybe on windows all files have the executable bit set.
-	// Either windows .exe or unix executable bit should be set.
-	if filepath.Ext(path) != ".exe" && fileinfo.Mode()&0111 == 0 {
+	if !filesystem.IsInterestingExecutable(path, fileinfo) {
 		return false
 	}