llvm-project/compiler-rt/lib/fuzzer/FuzzerExtFunctionsWeakAlias...

57 lines
1.8 KiB
C++

//===- FuzzerExtFunctionsWeakAlias.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 using weak aliases. Works for Windows.
//===----------------------------------------------------------------------===//
#include "FuzzerDefs.h"
#if LIBFUZZER_WINDOWS
#include "FuzzerExtFunctions.h"
#include "FuzzerIO.h"
using namespace fuzzer;
extern "C" {
// Declare these symbols as weak to allow them to be optionally defined.
#define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
RETURN_TYPE NAME##Def FUNC_SIG { \
Printf("ERROR: Function \"%s\" not defined.\n", #NAME); \
exit(1); \
} \
RETURN_TYPE NAME FUNC_SIG __attribute__((weak, alias(#NAME "Def")));
#include "FuzzerExtFunctions.def"
#undef EXT_FUNC
}
template <typename T>
static T *GetFnPtr(T *Fun, T *FunDef, const char *FnName, bool WarnIfMissing) {
if (Fun == FunDef) {
if (WarnIfMissing)
Printf("WARNING: Failed to find function \"%s\".\n", FnName);
return nullptr;
}
return Fun;
}
namespace fuzzer {
ExternalFunctions::ExternalFunctions() {
#define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
this->NAME = GetFnPtr<decltype(::NAME)>(::NAME, ::NAME##Def, #NAME, WARN);
#include "FuzzerExtFunctions.def"
#undef EXT_FUNC
}
} // namespace fuzzer
#endif // LIBFUZZER_WINDOWS