1 //===- SearchForAddressOfSpecialSymbol.cpp - Function addresses -*- C++ -*-===// 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 // 10 // This file pulls the addresses of certain symbols out of the linker. It must 11 // include as few header files as possible because it declares the symbols as 12 // void*, which would conflict with the actual symbol type if any header 13 // declared it. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include <string.h> 18 19 // Must declare the symbols in the global namespace. 20 static void *DoSearch(const char* symbolName) { 21 #define EXPLICIT_SYMBOL(SYM) \ 22 extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM 23 24 // If this is darwin, it has some funky issues, try to solve them here. Some 25 // important symbols are marked 'private external' which doesn't allow 26 // SearchForAddressOfSymbol to find them. As such, we special case them here, 27 // there is only a small handful of them. 28 29 #ifdef __APPLE__ 30 { 31 // __eprintf is sometimes used for assert() handling on x86. 32 // 33 // FIXME: Currently disabled when using Clang, as we don't always have our 34 // runtime support libraries available. 35 #ifndef __clang__ 36 #ifdef __i386__ 37 EXPLICIT_SYMBOL(__eprintf); 38 #endif 39 #endif 40 } 41 #endif 42 43 #ifdef __CYGWIN__ 44 { 45 EXPLICIT_SYMBOL(_alloca); 46 EXPLICIT_SYMBOL(__main); 47 } 48 #endif 49 50 #undef EXPLICIT_SYMBOL 51 return nullptr; 52 } 53 54 namespace llvm { 55 void *SearchForAddressOfSpecialSymbol(const char* symbolName) { 56 return DoSearch(symbolName); 57 } 58 } // namespace llvm 59
