SearchForAddressOfSpecialSymbol.cpp revision 218893
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 EXPLICIT_SYMBOL(__ashldi3); 32 EXPLICIT_SYMBOL(__ashrdi3); 33 EXPLICIT_SYMBOL(__cmpdi2); 34 EXPLICIT_SYMBOL(__divdi3); 35 EXPLICIT_SYMBOL(__fixdfdi); 36 EXPLICIT_SYMBOL(__fixsfdi); 37 EXPLICIT_SYMBOL(__fixunsdfdi); 38 EXPLICIT_SYMBOL(__fixunssfdi); 39 EXPLICIT_SYMBOL(__floatdidf); 40 EXPLICIT_SYMBOL(__floatdisf); 41 EXPLICIT_SYMBOL(__lshrdi3); 42 EXPLICIT_SYMBOL(__moddi3); 43 EXPLICIT_SYMBOL(__udivdi3); 44 EXPLICIT_SYMBOL(__umoddi3); 45 46 // __eprintf is sometimes used for assert() handling on x86. 47 // 48 // FIXME: Currently disabled when using Clang, as we don't always have our 49 // runtime support libraries available. 50#ifndef __clang__ 51#ifdef __i386__ 52 EXPLICIT_SYMBOL(__eprintf); 53#endif 54#endif 55 } 56#endif 57 58#ifdef __CYGWIN__ 59 { 60 EXPLICIT_SYMBOL(_alloca); 61 EXPLICIT_SYMBOL(__main); 62 } 63#endif 64 65#undef EXPLICIT_SYMBOL 66 return 0; 67} 68 69namespace llvm { 70void *SearchForAddressOfSpecialSymbol(const char* symbolName) { 71 return DoSearch(symbolName); 72} 73} // namespace llvm 74