//===- FuzzerExtFunctionsWeak.cpp - Interface to external functions -------===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

// 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 _<symbol_name>`` 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 "FuzzerDefs.h"

#if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FUCHSIA ||                \

    LIBFUZZER_FREEBSD || LIBFUZZER_OPENBSD

#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<void *>(reinterpret_cast<uintptr_t>(::NAME)),    \

             #NAME, WARN);

#include "FuzzerExtFunctions.def"

#undef EXT_FUNC

}

} // namespace fuzzer

#endif