//===- FuzzerExtFunctionsWeak.cpp - Interface to external functions -------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // Implementation for Linux. This relies on the linker's support for weak // symbols. We don't use this approach on Apple platforms because it requires // clients of LibFuzzer to pass ``-U _`` to the linker to allow // weak symbols to be undefined. That is a complication we don't want to expose // to clients right now. //===----------------------------------------------------------------------===// #include "FuzzerPlatform.h" #if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FUCHSIA || \ LIBFUZZER_FREEBSD || LIBFUZZER_OPENBSD || LIBFUZZER_EMSCRIPTEN #include "FuzzerExtFunctions.h" #include "FuzzerIO.h" extern "C" { // Declare these symbols as weak to allow them to be optionally defined. #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \ __attribute__((weak, visibility("default"))) RETURN_TYPE NAME FUNC_SIG #include "FuzzerExtFunctions.def" #undef EXT_FUNC } using namespace fuzzer; static void CheckFnPtr(void *FnPtr, const char *FnName, bool WarnIfMissing) { if (FnPtr == nullptr && WarnIfMissing) { Printf("WARNING: Failed to find function \"%s\".\n", FnName); } } namespace fuzzer { ExternalFunctions::ExternalFunctions() { #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \ this->NAME = ::NAME; \ CheckFnPtr(reinterpret_cast(reinterpret_cast(::NAME)), \ #NAME, WARN); #include "FuzzerExtFunctions.def" #undef EXT_FUNC } } // namespace fuzzer #endif