1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- 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 // Implementation of the runtime dynamic memory manager base class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Config/config.h" 15 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h" 16 #include "llvm/Support/DynamicLibrary.h" 17 #include "llvm/Support/ErrorHandling.h" 18 #include <cstdlib> 19 20 #ifdef __linux__ 21 // These includes used by RTDyldMemoryManager::getPointerToNamedFunction() 22 // for Glibc trickery. See comments in this function for more information. 23 #ifdef HAVE_SYS_STAT_H 24 #include <sys/stat.h> 25 #endif 26 #include <fcntl.h> 27 #include <unistd.h> 28 #endif 29 30 namespace llvm { 31 32 RTDyldMemoryManager::~RTDyldMemoryManager() {} 33 34 // Determine whether we can register EH tables. 35 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \ 36 !defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)) 37 #define HAVE_EHTABLE_SUPPORT 1 38 #else 39 #define HAVE_EHTABLE_SUPPORT 0 40 #endif 41 42 #if HAVE_EHTABLE_SUPPORT 43 extern "C" void __register_frame(void*); 44 extern "C" void __deregister_frame(void*); 45 #else 46 // The building compiler does not have __(de)register_frame but 47 // it may be found at runtime in a dynamically-loaded library. 48 // For example, this happens when building LLVM with Visual C++ 49 // but using the MingW runtime. 50 void __register_frame(void *p) { 51 static bool Searched = false; 52 static void *rf = 0; 53 54 if (!Searched) { 55 Searched = true; 56 rf = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( 57 "__register_frame"); 58 } 59 if (rf) 60 ((void (*)(void *))rf)(p); 61 } 62 63 void __deregister_frame(void *p) { 64 static bool Searched = false; 65 static void *df = 0; 66 67 if (!Searched) { 68 Searched = true; 69 df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( 70 "__deregister_frame"); 71 } 72 if (df) 73 ((void (*)(void *))df)(p); 74 } 75 #endif 76 77 #ifdef __APPLE__ 78 79 static const char *processFDE(const char *Entry, bool isDeregister) { 80 const char *P = Entry; 81 uint32_t Length = *((const uint32_t *)P); 82 P += 4; 83 uint32_t Offset = *((const uint32_t *)P); 84 if (Offset != 0) { 85 if (isDeregister) 86 __deregister_frame(const_cast<char *>(Entry)); 87 else 88 __register_frame(const_cast<char *>(Entry)); 89 } 90 return P + Length; 91 } 92 93 // This implementation handles frame registration for local targets. 94 // Memory managers for remote targets should re-implement this function 95 // and use the LoadAddr parameter. 96 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, 97 uint64_t LoadAddr, 98 size_t Size) { 99 // On OS X OS X __register_frame takes a single FDE as an argument. 100 // See http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-April/061768.html 101 const char *P = (const char *)Addr; 102 const char *End = P + Size; 103 do { 104 P = processFDE(P, false); 105 } while(P != End); 106 } 107 108 void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr, 109 uint64_t LoadAddr, 110 size_t Size) { 111 const char *P = (const char *)Addr; 112 const char *End = P + Size; 113 do { 114 P = processFDE(P, true); 115 } while(P != End); 116 } 117 118 #else 119 120 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, 121 uint64_t LoadAddr, 122 size_t Size) { 123 // On Linux __register_frame takes a single argument: 124 // a pointer to the start of the .eh_frame section. 125 126 // How can it find the end? Because crtendS.o is linked 127 // in and it has an .eh_frame section with four zero chars. 128 __register_frame(Addr); 129 } 130 131 void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr, 132 uint64_t LoadAddr, 133 size_t Size) { 134 __deregister_frame(Addr); 135 } 136 137 #endif 138 139 static int jit_noop() { 140 return 0; 141 } 142 143 // ARM math functions are statically linked on Android from libgcc.a, but not 144 // available at runtime for dynamic linking. On Linux these are usually placed 145 // in libgcc_s.so so can be found by normal dynamic lookup. 146 #if defined(__BIONIC__) && defined(__arm__) 147 // List of functions which are statically linked on Android and can be generated 148 // by LLVM. This is done as a nested macro which is used once to declare the 149 // imported functions with ARM_MATH_DECL and once to compare them to the 150 // user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test 151 // assumes that all functions start with __aeabi_ and getSymbolAddress must be 152 // modified if that changes. 153 #define ARM_MATH_IMPORTS(PP) \ 154 PP(__aeabi_d2f) \ 155 PP(__aeabi_d2iz) \ 156 PP(__aeabi_d2lz) \ 157 PP(__aeabi_d2uiz) \ 158 PP(__aeabi_d2ulz) \ 159 PP(__aeabi_dadd) \ 160 PP(__aeabi_dcmpeq) \ 161 PP(__aeabi_dcmpge) \ 162 PP(__aeabi_dcmpgt) \ 163 PP(__aeabi_dcmple) \ 164 PP(__aeabi_dcmplt) \ 165 PP(__aeabi_dcmpun) \ 166 PP(__aeabi_ddiv) \ 167 PP(__aeabi_dmul) \ 168 PP(__aeabi_dsub) \ 169 PP(__aeabi_f2d) \ 170 PP(__aeabi_f2iz) \ 171 PP(__aeabi_f2lz) \ 172 PP(__aeabi_f2uiz) \ 173 PP(__aeabi_f2ulz) \ 174 PP(__aeabi_fadd) \ 175 PP(__aeabi_fcmpeq) \ 176 PP(__aeabi_fcmpge) \ 177 PP(__aeabi_fcmpgt) \ 178 PP(__aeabi_fcmple) \ 179 PP(__aeabi_fcmplt) \ 180 PP(__aeabi_fcmpun) \ 181 PP(__aeabi_fdiv) \ 182 PP(__aeabi_fmul) \ 183 PP(__aeabi_fsub) \ 184 PP(__aeabi_i2d) \ 185 PP(__aeabi_i2f) \ 186 PP(__aeabi_idiv) \ 187 PP(__aeabi_idivmod) \ 188 PP(__aeabi_l2d) \ 189 PP(__aeabi_l2f) \ 190 PP(__aeabi_lasr) \ 191 PP(__aeabi_ldivmod) \ 192 PP(__aeabi_llsl) \ 193 PP(__aeabi_llsr) \ 194 PP(__aeabi_lmul) \ 195 PP(__aeabi_ui2d) \ 196 PP(__aeabi_ui2f) \ 197 PP(__aeabi_uidiv) \ 198 PP(__aeabi_uidivmod) \ 199 PP(__aeabi_ul2d) \ 200 PP(__aeabi_ul2f) \ 201 PP(__aeabi_uldivmod) 202 203 // Declare statically linked math functions on ARM. The function declarations 204 // here do not have the correct prototypes for each function in 205 // ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are 206 // needed. In particular the __aeabi_*divmod functions do not have calling 207 // conventions which match any C prototype. 208 #define ARM_MATH_DECL(name) extern "C" void name(); 209 ARM_MATH_IMPORTS(ARM_MATH_DECL) 210 #undef ARM_MATH_DECL 211 #endif 212 213 uint64_t RTDyldMemoryManager::getSymbolAddress(const std::string &Name) { 214 // This implementation assumes that the host program is the target. 215 // Clients generating code for a remote target should implement their own 216 // memory manager. 217 #if defined(__linux__) && defined(__GLIBC__) 218 //===--------------------------------------------------------------------===// 219 // Function stubs that are invoked instead of certain library calls 220 // 221 // Force the following functions to be linked in to anything that uses the 222 // JIT. This is a hack designed to work around the all-too-clever Glibc 223 // strategy of making these functions work differently when inlined vs. when 224 // not inlined, and hiding their real definitions in a separate archive file 225 // that the dynamic linker can't see. For more info, search for 226 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274. 227 if (Name == "stat") return (uint64_t)&stat; 228 if (Name == "fstat") return (uint64_t)&fstat; 229 if (Name == "lstat") return (uint64_t)&lstat; 230 if (Name == "stat64") return (uint64_t)&stat64; 231 if (Name == "fstat64") return (uint64_t)&fstat64; 232 if (Name == "lstat64") return (uint64_t)&lstat64; 233 if (Name == "atexit") return (uint64_t)&atexit; 234 if (Name == "mknod") return (uint64_t)&mknod; 235 #endif // __linux__ && __GLIBC__ 236 237 // See ARM_MATH_IMPORTS definition for explanation 238 #if defined(__BIONIC__) && defined(__arm__) 239 if (Name.compare(0, 8, "__aeabi_") == 0) { 240 // Check if the user has requested any of the functions listed in 241 // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol. 242 #define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn; 243 ARM_MATH_IMPORTS(ARM_MATH_CHECK) 244 #undef ARM_MATH_CHECK 245 } 246 #endif 247 248 // We should not invoke parent's ctors/dtors from generated main()! 249 // On Mingw and Cygwin, the symbol __main is resolved to 250 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors 251 // (and register wrong callee's dtors with atexit(3)). 252 // We expect ExecutionEngine::runStaticConstructorsDestructors() 253 // is called before ExecutionEngine::runFunctionAsMain() is called. 254 if (Name == "__main") return (uint64_t)&jit_noop; 255 256 const char *NameStr = Name.c_str(); 257 void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); 258 if (Ptr) 259 return (uint64_t)Ptr; 260 261 // If it wasn't found and if it starts with an underscore ('_') character, 262 // try again without the underscore. 263 if (NameStr[0] == '_') { 264 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1); 265 if (Ptr) 266 return (uint64_t)Ptr; 267 } 268 return 0; 269 } 270 271 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name, 272 bool AbortOnFailure) { 273 uint64_t Addr = getSymbolAddress(Name); 274 275 if (!Addr && AbortOnFailure) 276 report_fatal_error("Program used external function '" + Name + 277 "' which could not be resolved!"); 278 return (void*)Addr; 279 } 280 281 } // namespace llvm 282
