1 files changed, 96 insertions, 0 deletions
diff --git a/src/cmd/cgo/internal/testsanitizers/libfuzzer_test.go b/src/cmd/cgo/internal/testsanitizers/libfuzzer_test.go
new file mode 100644
index 0000000..3f5b1d9
--- /dev/null
+++ b/src/cmd/cgo/internal/testsanitizers/libfuzzer_test.go
@@ -0,0 +1,96 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build linux || (freebsd && amd64)
+
+package sanitizers_test
+
+import (
+	"internal/testenv"
+	"strings"
+	"testing"
+)
+
+func TestLibFuzzer(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	goos, err := goEnv("GOOS")
+	if err != nil {
+		t.Fatal(err)
+	}
+	goarch, err := goEnv("GOARCH")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !libFuzzerSupported(goos, goarch) {
+		t.Skipf("skipping on %s/%s; libfuzzer option is not supported.", goos, goarch)
+	}
+	config := configure("fuzzer")
+	config.skipIfCSanitizerBroken(t)
+
+	cases := []struct {
+		goSrc         string
+		cSrc          string
+		expectedError string
+	}{
+		{goSrc: "libfuzzer1.go", expectedError: "panic: found it"},
+		{goSrc: "libfuzzer2.go", cSrc: "libfuzzer2.c", expectedError: "panic: found it"},
+	}
+	for _, tc := range cases {
+		tc := tc
+		name := strings.TrimSuffix(tc.goSrc, ".go")
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := newTempDir(t)
+			defer dir.RemoveAll(t)
+
+			// build Go code in libfuzzer mode to a c-archive
+			outPath := dir.Join(name)
+			archivePath := dir.Join(name + ".a")
+			mustRun(t, config.goCmd("build", "-buildmode=c-archive", "-o", archivePath, srcPath(tc.goSrc)))
+
+			// build C code (if any) and link with Go code
+			cmd, err := cc(config.cFlags...)
+			if err != nil {
+				t.Fatalf("error running cc: %v", err)
+			}
+			cmd.Args = append(cmd.Args, config.ldFlags...)
+			cmd.Args = append(cmd.Args, "-o", outPath, "-I", dir.Base())
+			if tc.cSrc != "" {
+				cmd.Args = append(cmd.Args, srcPath(tc.cSrc))
+			}
+			cmd.Args = append(cmd.Args, archivePath)
+			mustRun(t, cmd)
+
+			cmd = hangProneCmd(outPath)
+			cmd.Dir = dir.Base()
+			outb, err := cmd.CombinedOutput()
+			out := string(outb)
+			if err == nil {
+				t.Fatalf("fuzzing succeeded unexpectedly; output:\n%s", out)
+			}
+			if !strings.Contains(out, tc.expectedError) {
+				t.Errorf("exited without expected error %q; got\n%s", tc.expectedError, out)
+			}
+		})
+	}
+}
+
+// libFuzzerSupported is a copy of the function internal/platform.FuzzInstrumented,
+// because the internal package can't be used here.
+func libFuzzerSupported(goos, goarch string) bool {
+	switch goarch {
+	case "amd64", "arm64":
+		// TODO(#14565): support more architectures.
+		switch goos {
+		case "darwin", "freebsd", "linux", "windows":
+			return true
+		default:
+			return false
+		}
+	default:
+		return false
+	}
+}