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| //===- FuzzerExtFunctionsDlsym.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 operating systems that support dlsym(). We only use it on
// Apple platforms for now. We don't use this approach on Linux because it
// requires that clients of LibFuzzer pass ``--export-dynamic`` to the linker.
// That is a complication we don't wish to expose to clients right now.
//===----------------------------------------------------------------------===//
#include "FuzzerDefs.h"
#if LIBFUZZER_APPLE
#include "FuzzerExtFunctions.h"
#include "FuzzerIO.h"
#include <dlfcn.h>
using namespace fuzzer;
template <typename T>
static T GetFnPtr(const char *FnName, bool WarnIfMissing) {
dlerror(); // Clear any previous errors.
void *Fn = dlsym(RTLD_DEFAULT, FnName);
if (Fn == nullptr) {
if (WarnIfMissing) {
const char *ErrorMsg = dlerror();
Printf("WARNING: Failed to find function \"%s\".", FnName);
if (ErrorMsg)
Printf(" Reason %s.", ErrorMsg);
Printf("\n");
}
}
return reinterpret_cast<T>(Fn);
}
namespace fuzzer {
ExternalFunctions::ExternalFunctions() {
#define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
this->NAME = GetFnPtr<decltype(ExternalFunctions::NAME)>(#NAME, WARN)
#include "FuzzerExtFunctions.def"
#undef EXT_FUNC
}
} // namespace fuzzer
#endif // LIBFUZZER_APPLE
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