test: Build fuzz targets into seperate executables

src/test/fuzz/fuzz.cpp

@@ -0,0 +1,77 @@
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/fuzz/fuzz.h>
+
+#include <unistd.h>
+
+#include <pubkey.h>
+#include <util/memory.h>
+
+
+static bool read_stdin(std::vector<uint8_t>& data)
+{
+    uint8_t buffer[1024];
+    ssize_t length = 0;
+    while ((length = read(STDIN_FILENO, buffer, 1024)) > 0) {
+        data.insert(data.end(), buffer, buffer + length);
+
+        if (data.size() > (1 << 20)) return false;
+    }
+    return length == 0;
+}
+
+static void initialize()
+{
+    const static auto verify_handle = MakeUnique<ECCVerifyHandle>();
+}
+
+// This function is used by libFuzzer
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+{
+    test_one_input(std::vector<uint8_t>(data, data + size));
+    return 0;
+}
+
+// This function is used by libFuzzer
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv)
+{
+    initialize();
+    return 0;
+}
+
+// Disabled under WIN32 due to clash with Cygwin's WinMain.
+#ifndef WIN32
+// Declare main(...) "weak" to allow for libFuzzer linking. libFuzzer provides
+// the main(...) function.
+__attribute__((weak))
+#endif
+int main(int argc, char **argv)
+{
+    initialize();
+#ifdef __AFL_INIT
+    // Enable AFL deferred forkserver mode. Requires compilation using
+    // afl-clang-fast++. See fuzzing.md for details.
+    __AFL_INIT();
+#endif
+
+#ifdef __AFL_LOOP
+    // Enable AFL persistent mode. Requires compilation using afl-clang-fast++.
+    // See fuzzing.md for details.
+    while (__AFL_LOOP(1000)) {
+        std::vector<uint8_t> buffer;
+        if (!read_stdin(buffer)) {
+            continue;
+        }
+        test_one_input(buffer);
+    }
+#else
+    std::vector<uint8_t> buffer;
+    if (!read_stdin(buffer)) {
+        return 0;
+    }
+    test_one_input(buffer);
+#endif
+    return 0;
+}