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>
GetFnPtr(T * Fun,T * FunDef,const char * FnName,bool WarnIfMissing)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
ExternalFunctions()45 ExternalFunctions::ExternalFunctions() {
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
57