LLVM  6.0.0svn
FuzzerExtFunctionsWeakAlias.cpp
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1 //===- FuzzerExtFunctionsWeakAlias.cpp - Interface to external functions --===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // Implementation using weak aliases. Works for Windows.
10 //===----------------------------------------------------------------------===//
11 #include "FuzzerDefs.h"
12 #if LIBFUZZER_WINDOWS
13 
14 #include "FuzzerExtFunctions.h"
15 #include "FuzzerIO.h"
16 
17 using namespace fuzzer;
18 
19 extern "C" {
20 // Declare these symbols as weak to allow them to be optionally defined.
21 #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
22  RETURN_TYPE NAME##Def FUNC_SIG { \
23  Printf("ERROR: Function \"%s\" not defined.\n", #NAME); \
24  exit(1); \
25  } \
26  RETURN_TYPE NAME FUNC_SIG __attribute__((weak, alias(#NAME "Def")));
27 
28 #include "FuzzerExtFunctions.def"
29 
30 #undef EXT_FUNC
31 }
32 
33 template <typename T>
34 static T *GetFnPtr(T *Fun, T *FunDef, const char *FnName, bool WarnIfMissing) {
35  if (Fun == FunDef) {
36  if (WarnIfMissing)
37  Printf("WARNING: Failed to find function \"%s\".\n", FnName);
38  return nullptr;
39  }
40  return Fun;
41 }
42 
43 namespace fuzzer {
44 
46 #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
47  this->NAME = GetFnPtr<decltype(::NAME)>(::NAME, ::NAME##Def, #NAME, WARN);
48 
49 #include "FuzzerExtFunctions.def"
50 
51 #undef EXT_FUNC
52 }
53 
54 } // namespace fuzzer
55 
56 #endif // LIBFUZZER_WINDOWS
void Printf(const char *Fmt,...)
Definition: FuzzerIO.cpp:112