294 lines · cpp
1//===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// Implementation of the runtime dynamic memory manager base class.10//11//===----------------------------------------------------------------------===//12 13#include "llvm/Config/config.h"14#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"15#include "llvm/Support/Compiler.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#include <fcntl.h>24#include <sys/stat.h>25#include <unistd.h>26#endif27 28namespace llvm {29 30RTDyldMemoryManager::~RTDyldMemoryManager() = default;31 32#if defined(HAVE_REGISTER_FRAME) && defined(HAVE_DEREGISTER_FRAME) && \33 !defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)34extern "C" void __register_frame(void *);35extern "C" void __deregister_frame(void *);36#else37// The building compiler does not have __(de)register_frame but38// it may be found at runtime in a dynamically-loaded library.39// For example, this happens when building LLVM with Visual C++40// but using the MingW runtime.41static void __register_frame(void *p) {42 static bool Searched = false;43 static void (*rf)(void *) = 0;44 45 if (!Searched) {46 Searched = true;47 *(void **)&rf =48 llvm::sys::DynamicLibrary::SearchForAddressOfSymbol("__register_frame");49 }50 if (rf)51 rf(p);52}53 54static void __deregister_frame(void *p) {55 static bool Searched = false;56 static void (*df)(void *) = 0;57 58 if (!Searched) {59 Searched = true;60 *(void **)&df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(61 "__deregister_frame");62 }63 if (df)64 df(p);65}66#endif67 68/* libgcc and libunwind __register_frame behave differently. We use the presence69 * of __unw_add_dynamic_fde to detect libunwind. */70#if defined(HAVE_UNW_ADD_DYNAMIC_FDE) || defined(__APPLE__)71 72static const char *processFDE(const char *Entry, bool isDeregister) {73 const char *P = Entry;74 uint32_t Length = *((const uint32_t *)P);75 P += 4;76 uint32_t Offset = *((const uint32_t *)P);77 if (Offset != 0) {78 if (isDeregister)79 __deregister_frame(const_cast<char *>(Entry));80 else81 __register_frame(const_cast<char *>(Entry));82 }83 return P + Length;84}85 86// This implementation handles frame registration for local targets.87// Memory managers for remote targets should re-implement this function88// and use the LoadAddr parameter.89void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr,90 size_t Size) {91 // On OS X OS X __register_frame takes a single FDE as an argument.92 // See http://lists.llvm.org/pipermail/llvm-dev/2013-April/061737.html93 // and projects/libunwind/src/UnwindLevel1-gcc-ext.c.94 const char *P = (const char *)Addr;95 const char *End = P + Size;96 while (P != End)97 P = processFDE(P, false);98}99 100void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr,101 size_t Size) {102 const char *P = (const char *)Addr;103 const char *End = P + Size;104 while (P != End)105 P = processFDE(P, true);106}107 108#else109 110void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr,111 size_t Size) {112 // On Linux __register_frame takes a single argument:113 // a pointer to the start of the .eh_frame section.114 115 // How can it find the end? Because crtendS.o is linked116 // in and it has an .eh_frame section with four zero chars.117 __register_frame(Addr);118}119 120void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr,121 size_t Size) {122 __deregister_frame(Addr);123}124 125#endif126 127void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,128 size_t Size) {129 registerEHFramesInProcess(Addr, Size);130 EHFrames.push_back({Addr, Size});131}132 133void RTDyldMemoryManager::deregisterEHFrames() {134 for (auto &Frame : EHFrames)135 deregisterEHFramesInProcess(Frame.Addr, Frame.Size);136 EHFrames.clear();137}138 139static int jit_noop() {140 return 0;141}142 143// ARM math functions are statically linked on Android from libgcc.a, but not144// available at runtime for dynamic linking. On Linux these are usually placed145// 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 generated148// by LLVM. This is done as a nested macro which is used once to declare the149// imported functions with ARM_MATH_DECL and once to compare them to the150// user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test151// assumes that all functions start with __aeabi_ and getSymbolAddress must be152// 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 declarations204// here do not have the correct prototypes for each function in205// ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are206// needed. In particular the __aeabi_*divmod functions do not have calling207// conventions which match any C prototype.208#define ARM_MATH_DECL(name) extern "C" void name();209ARM_MATH_IMPORTS(ARM_MATH_DECL)210#undef ARM_MATH_DECL211#endif212 213#if defined(__linux__) && defined(__GLIBC__) && \214 (defined(__i386__) || defined(__x86_64__))215extern "C" LLVM_ATTRIBUTE_WEAK void __morestack();216#endif217 218uint64_t219RTDyldMemoryManager::getSymbolAddressInProcess(const std::string &Name) {220 // This implementation assumes that the host program is the target.221 // Clients generating code for a remote target should implement their own222 // memory manager.223#if defined(__linux__) && defined(__GLIBC__)224 //===--------------------------------------------------------------------===//225 // Function stubs that are invoked instead of certain library calls226 //227 // Force the following functions to be linked in to anything that uses the228 // JIT. This is a hack designed to work around the all-too-clever Glibc229 // strategy of making these functions work differently when inlined vs. when230 // not inlined, and hiding their real definitions in a separate archive file231 // that the dynamic linker can't see. For more info, search for232 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.233 if (Name == "stat") return (uint64_t)&stat;234 if (Name == "fstat") return (uint64_t)&fstat;235 if (Name == "lstat") return (uint64_t)&lstat;236 if (Name == "stat64") return (uint64_t)&stat64;237 if (Name == "fstat64") return (uint64_t)&fstat64;238 if (Name == "lstat64") return (uint64_t)&lstat64;239 if (Name == "atexit") return (uint64_t)&atexit;240 if (Name == "mknod") return (uint64_t)&mknod;241 242#if defined(__i386__) || defined(__x86_64__)243 // __morestack lives in libgcc, a static library.244 if (&__morestack && Name == "__morestack")245 return (uint64_t)&__morestack;246#endif247#endif // __linux__ && __GLIBC__248 249 // See ARM_MATH_IMPORTS definition for explanation250#if defined(__BIONIC__) && defined(__arm__)251 if (Name.compare(0, 8, "__aeabi_") == 0) {252 // Check if the user has requested any of the functions listed in253 // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol.254#define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn;255 ARM_MATH_IMPORTS(ARM_MATH_CHECK)256#undef ARM_MATH_CHECK257 }258#endif259 260 // We should not invoke parent's ctors/dtors from generated main()!261 // On Mingw and Cygwin, the symbol __main is resolved to262 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors263 // (and register wrong callee's dtors with atexit(3)).264 // We expect ExecutionEngine::runStaticConstructorsDestructors()265 // is called before ExecutionEngine::runFunctionAsMain() is called.266 if (Name == "__main") return (uint64_t)&jit_noop;267 268 const char *NameStr = Name.c_str();269 270 // DynamicLibrary::SearchForAddressOfSymbol expects an unmangled 'C' symbol271 // name so ff we're on Darwin, strip the leading '_' off.272#ifdef __APPLE__273 if (NameStr[0] == '_')274 ++NameStr;275#endif276 277 return (uint64_t)sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);278}279 280void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,281 bool AbortOnFailure) {282 uint64_t Addr = getSymbolAddress(Name);283 284 if (!Addr && AbortOnFailure)285 report_fatal_error(Twine("Program used external function '") + Name +286 "' which could not be resolved!");287 288 return (void*)Addr;289}290 291void RTDyldMemoryManager::anchor() {}292void MCJITMemoryManager::anchor() {}293} // namespace llvm294