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/Compiler.h" 17 #include "llvm/Support/DynamicLibrary.h" 18 #include "llvm/Support/ErrorHandling.h" 19 #include <cstdlib> 20 21 #ifdef __linux__ 22 // These includes used by RTDyldMemoryManager::getPointerToNamedFunction() 23 // for Glibc trickery. See comments in this function for more information. 24 #ifdef HAVE_SYS_STAT_H 25 #include <sys/stat.h> 26 #endif 27 #include <fcntl.h> 28 #include <unistd.h> 29 #endif 30 31 namespace llvm { 32 33 RTDyldMemoryManager::~RTDyldMemoryManager() {} 34 35 // Determine whether we can register EH tables. 36 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \ 37 !defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)) 38 #define HAVE_EHTABLE_SUPPORT 1 39 #else 40 #define HAVE_EHTABLE_SUPPORT 0 41 #endif 42 43 #if HAVE_EHTABLE_SUPPORT 44 extern "C" void __register_frame(void*); 45 extern "C" void __deregister_frame(void*); 46 #else 47 // The building compiler does not have __(de)register_frame but 48 // it may be found at runtime in a dynamically-loaded library. 49 // For example, this happens when building LLVM with Visual C++ 50 // but using the MingW runtime. 51 void __register_frame(void *p) { 52 static bool Searched = false; 53 static void *rf = 0; 54 55 if (!Searched) { 56 Searched = true; 57 rf = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( 58 "__register_frame"); 59 } 60 if (rf) 61 ((void (*)(void *))rf)(p); 62 } 63 64 void __deregister_frame(void *p) { 65 static bool Searched = false; 66 static void *df = 0; 67 68 if (!Searched) { 69 Searched = true; 70 df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( 71 "__deregister_frame"); 72 } 73 if (df) 74 ((void (*)(void *))df)(p); 75 } 76 #endif 77 78 #ifdef __APPLE__ 79 80 static const char *processFDE(const char *Entry, bool isDeregister) { 81 const char *P = Entry; 82 uint32_t Length = *((const uint32_t *)P); 83 P += 4; 84 uint32_t Offset = *((const uint32_t *)P); 85 if (Offset != 0) { 86 if (isDeregister) 87 __deregister_frame(const_cast<char *>(Entry)); 88 else 89 __register_frame(const_cast<char *>(Entry)); 90 } 91 return P + Length; 92 } 93 94 // This implementation handles frame registration for local targets. 95 // Memory managers for remote targets should re-implement this function 96 // and use the LoadAddr parameter. 97 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, 98 uint64_t LoadAddr, 99 size_t Size) { 100 // On OS X OS X __register_frame takes a single FDE as an argument. 101 // See http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-April/061768.html 102 const char *P = (const char *)Addr; 103 const char *End = P + Size; 104 do { 105 P = processFDE(P, false); 106 } while(P != End); 107 } 108 109 void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr, 110 uint64_t LoadAddr, 111 size_t Size) { 112 const char *P = (const char *)Addr; 113 const char *End = P + Size; 114 do { 115 P = processFDE(P, true); 116 } while(P != End); 117 } 118 119 #else 120 121 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, 122 uint64_t LoadAddr, 123 size_t Size) { 124 // On Linux __register_frame takes a single argument: 125 // a pointer to the start of the .eh_frame section. 126 127 // How can it find the end? Because crtendS.o is linked 128 // in and it has an .eh_frame section with four zero chars. 129 __register_frame(Addr); 130 } 131 132 void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr, 133 uint64_t LoadAddr, 134 size_t Size) { 135 __deregister_frame(Addr); 136 } 137 138 #endif 139 140 static int jit_noop() { 141 return 0; 142 } 143 144 // ARM math functions are statically linked on Android from libgcc.a, but not 145 // available at runtime for dynamic linking. On Linux these are usually placed 146 // in libgcc_s.so so can be found by normal dynamic lookup. 147 #if defined(__BIONIC__) && defined(__arm__) 148 // List of functions which are statically linked on Android and can be generated 149 // by LLVM. This is done as a nested macro which is used once to declare the 150 // imported functions with ARM_MATH_DECL and once to compare them to the 151 // user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test 152 // assumes that all functions start with __aeabi_ and getSymbolAddress must be 153 // modified if that changes. 154 #define ARM_MATH_IMPORTS(PP) \ 155 PP(__aeabi_d2f) \ 156 PP(__aeabi_d2iz) \ 157 PP(__aeabi_d2lz) \ 158 PP(__aeabi_d2uiz) \ 159 PP(__aeabi_d2ulz) \ 160 PP(__aeabi_dadd) \ 161 PP(__aeabi_dcmpeq) \ 162 PP(__aeabi_dcmpge) \ 163 PP(__aeabi_dcmpgt) \ 164 PP(__aeabi_dcmple) \ 165 PP(__aeabi_dcmplt) \ 166 PP(__aeabi_dcmpun) \ 167 PP(__aeabi_ddiv) \ 168 PP(__aeabi_dmul) \ 169 PP(__aeabi_dsub) \ 170 PP(__aeabi_f2d) \ 171 PP(__aeabi_f2iz) \ 172 PP(__aeabi_f2lz) \ 173 PP(__aeabi_f2uiz) \ 174 PP(__aeabi_f2ulz) \ 175 PP(__aeabi_fadd) \ 176 PP(__aeabi_fcmpeq) \ 177 PP(__aeabi_fcmpge) \ 178 PP(__aeabi_fcmpgt) \ 179 PP(__aeabi_fcmple) \ 180 PP(__aeabi_fcmplt) \ 181 PP(__aeabi_fcmpun) \ 182 PP(__aeabi_fdiv) \ 183 PP(__aeabi_fmul) \ 184 PP(__aeabi_fsub) \ 185 PP(__aeabi_i2d) \ 186 PP(__aeabi_i2f) \ 187 PP(__aeabi_idiv) \ 188 PP(__aeabi_idivmod) \ 189 PP(__aeabi_l2d) \ 190 PP(__aeabi_l2f) \ 191 PP(__aeabi_lasr) \ 192 PP(__aeabi_ldivmod) \ 193 PP(__aeabi_llsl) \ 194 PP(__aeabi_llsr) \ 195 PP(__aeabi_lmul) \ 196 PP(__aeabi_ui2d) \ 197 PP(__aeabi_ui2f) \ 198 PP(__aeabi_uidiv) \ 199 PP(__aeabi_uidivmod) \ 200 PP(__aeabi_ul2d) \ 201 PP(__aeabi_ul2f) \ 202 PP(__aeabi_uldivmod) 203 204 // Declare statically linked math functions on ARM. The function declarations 205 // here do not have the correct prototypes for each function in 206 // ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are 207 // needed. In particular the __aeabi_*divmod functions do not have calling 208 // conventions which match any C prototype. 209 #define ARM_MATH_DECL(name) extern "C" void name(); 210 ARM_MATH_IMPORTS(ARM_MATH_DECL) 211 #undef ARM_MATH_DECL 212 #endif 213 214 #if defined(__linux__) && defined(__GLIBC__) && \ 215 (defined(__i386__) || defined(__x86_64__)) 216 extern "C" LLVM_ATTRIBUTE_WEAK void __morestack(); 217 #endif 218 219 uint64_t 220 RTDyldMemoryManager::getSymbolAddressInProcess(const std::string &Name) { 221 // This implementation assumes that the host program is the target. 222 // Clients generating code for a remote target should implement their own 223 // memory manager. 224 #if defined(__linux__) && defined(__GLIBC__) 225 //===--------------------------------------------------------------------===// 226 // Function stubs that are invoked instead of certain library calls 227 // 228 // Force the following functions to be linked in to anything that uses the 229 // JIT. This is a hack designed to work around the all-too-clever Glibc 230 // strategy of making these functions work differently when inlined vs. when 231 // not inlined, and hiding their real definitions in a separate archive file 232 // that the dynamic linker can't see. For more info, search for 233 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274. 234 if (Name == "stat") return (uint64_t)&stat; 235 if (Name == "fstat") return (uint64_t)&fstat; 236 if (Name == "lstat") return (uint64_t)&lstat; 237 if (Name == "stat64") return (uint64_t)&stat64; 238 if (Name == "fstat64") return (uint64_t)&fstat64; 239 if (Name == "lstat64") return (uint64_t)&lstat64; 240 if (Name == "atexit") return (uint64_t)&atexit; 241 if (Name == "mknod") return (uint64_t)&mknod; 242 243 #if defined(__i386__) || defined(__x86_64__) 244 // __morestack lives in libgcc, a static library. 245 if (&__morestack && Name == "__morestack") 246 return (uint64_t)&__morestack; 247 #endif 248 #endif // __linux__ && __GLIBC__ 249 250 // See ARM_MATH_IMPORTS definition for explanation 251 #if defined(__BIONIC__) && defined(__arm__) 252 if (Name.compare(0, 8, "__aeabi_") == 0) { 253 // Check if the user has requested any of the functions listed in 254 // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol. 255 #define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn; 256 ARM_MATH_IMPORTS(ARM_MATH_CHECK) 257 #undef ARM_MATH_CHECK 258 } 259 #endif 260 261 // We should not invoke parent's ctors/dtors from generated main()! 262 // On Mingw and Cygwin, the symbol __main is resolved to 263 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors 264 // (and register wrong callee's dtors with atexit(3)). 265 // We expect ExecutionEngine::runStaticConstructorsDestructors() 266 // is called before ExecutionEngine::runFunctionAsMain() is called. 267 if (Name == "__main") return (uint64_t)&jit_noop; 268 269 // Try to demangle Name before looking it up in the process, otherwise symbol 270 // '_<Name>' (if present) will shadow '<Name>', and there will be no way to 271 // refer to the latter. 272 273 const char *NameStr = Name.c_str(); 274 275 if (NameStr[0] == '_') 276 if (void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr + 1)) 277 return (uint64_t)Ptr; 278 279 // If we Name did not require demangling, or we failed to find the demangled 280 // name, try again without demangling. 281 return (uint64_t)sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); 282 } 283 284 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name, 285 bool AbortOnFailure) { 286 uint64_t Addr = getSymbolAddress(Name); 287 288 if (!Addr && AbortOnFailure) 289 report_fatal_error("Program used external function '" + Name + 290 "' which could not be resolved!"); 291 return (void*)Addr; 292 } 293 294 } // namespace llvm 295
