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. 20static 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 54namespace llvm { 55void *SearchForAddressOfSpecialSymbol(const char* symbolName) { 56 return DoSearch(symbolName); 57} 58} // namespace llvm 59