Add llvm fuzzer for CPDF_PSEngine

Put class definition into its own header file so fuzzer can find it.

Fix a pair of div by 0s immediately hit by the fuzzer.

Review-Url: https://codereview.chromium.org/2253193003

2 files changed, 29 insertions, 0 deletions

diff --git a/testing/libfuzzer/BUILD.gn b/testing/libfuzzer/BUILD.gn
index 1b7a7fb456..718a1db3c0 100644
--- a/testing/libfuzzer/BUILD.gn
+++ b/testing/libfuzzer/BUILD.gn
@@ -168,3 +168,18 @@ source_set("pdf_jpx_fuzzer") {
     ":libfuzzer_config",
   ]
 }
+
+source_set("pdf_psengine_fuzzer") {
+  testonly = true
+  sources = [
+    "pdf_psengine_fuzzer.cc",
+  ]
+  deps = [
+    "//third_party/pdfium:pdfium",
+  ]
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+    ":libfuzzer_config",
+  ]
+}
diff --git a/testing/libfuzzer/pdf_psengine_fuzzer.cc b/testing/libfuzzer/pdf_psengine_fuzzer.cc
new file mode 100644
index 0000000000..89f582ec64
--- /dev/null
+++ b/testing/libfuzzer/pdf_psengine_fuzzer.cc
@@ -0,0 +1,14 @@
+// Copyright 2016 The PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/fpdf_page/cpdf_psengine.h"
+
+#include <cstdint>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  CPDF_PSEngine engine;
+  if (engine.Parse(reinterpret_cast<const char*>(data), size))
+    engine.Execute();
+  return 0;
+}