Copy some fuzzer code from Chromium into PDFium.

These came from Chromium's pdf/pdfium/fuzzer directory. The code has
been modified to be buildable in standalone PDFium and modernized.

Change-Id: Ia4ddad4a164f798689af4b9f92d41d635901dccb
Reviewed-on: https://pdfium-review.googlesource.com/c/43530
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/testing/fuzzers/pdfium_xfa_fuzzer.cc b/testing/fuzzers/pdfium_xfa_fuzzer.cc
new file mode 100644
index 0000000000..f9a69d4166
--- /dev/null
+++ b/testing/fuzzers/pdfium_xfa_fuzzer.cc
@@ -0,0 +1,31 @@
+// Copyright 2017 The Chromium 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 <stdint.h>
+
+#include "public/fpdf_formfill.h"
+#include "testing/fuzzers/pdfium_fuzzer_helper.h"
+
+class PDFiumXFAFuzzer : public PDFiumFuzzerHelper {
+ public:
+  PDFiumXFAFuzzer() = default;
+  ~PDFiumXFAFuzzer() override = default;
+
+  int GetFormCallbackVersion() const override { return 2; }
+
+  // Return false if XFA doesn't load as otherwise we're duplicating the work
+  // done by the non-xfa fuzzer.
+  bool OnFormFillEnvLoaded(FPDF_DOCUMENT doc) override {
+    int form_type = FPDF_GetFormType(doc);
+    if (form_type != FORMTYPE_XFA_FULL && form_type != FORMTYPE_XFA_FOREGROUND)
+      return false;
+    return FPDF_LoadXFA(doc);
+  }
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  PDFiumXFAFuzzer fuzzer;
+  fuzzer.RenderPdf(reinterpret_cast<const char*>(data), size);
+  return 0;
+}