JIT.cpp revision 199481
1//===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===// 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 tool implements a just-in-time compiler for LLVM, allowing direct 11// execution of LLVM bitcode in an efficient manner. 12// 13//===----------------------------------------------------------------------===// 14 15#include "JIT.h" 16#include "llvm/Constants.h" 17#include "llvm/DerivedTypes.h" 18#include "llvm/Function.h" 19#include "llvm/GlobalVariable.h" 20#include "llvm/Instructions.h" 21#include "llvm/ModuleProvider.h" 22#include "llvm/CodeGen/JITCodeEmitter.h" 23#include "llvm/CodeGen/MachineCodeInfo.h" 24#include "llvm/ExecutionEngine/GenericValue.h" 25#include "llvm/ExecutionEngine/JITEventListener.h" 26#include "llvm/Target/TargetData.h" 27#include "llvm/Target/TargetMachine.h" 28#include "llvm/Target/TargetJITInfo.h" 29#include "llvm/Support/Dwarf.h" 30#include "llvm/Support/ErrorHandling.h" 31#include "llvm/Support/MutexGuard.h" 32#include "llvm/System/DynamicLibrary.h" 33#include "llvm/Config/config.h" 34 35using namespace llvm; 36 37#ifdef __APPLE__ 38// Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead 39// of atexit). It passes the address of linker generated symbol __dso_handle 40// to the function. 41// This configuration change happened at version 5330. 42# include <AvailabilityMacros.h> 43# if defined(MAC_OS_X_VERSION_10_4) && \ 44 ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \ 45 (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \ 46 __APPLE_CC__ >= 5330)) 47# ifndef HAVE___DSO_HANDLE 48# define HAVE___DSO_HANDLE 1 49# endif 50# endif 51#endif 52 53#if HAVE___DSO_HANDLE 54extern void *__dso_handle __attribute__ ((__visibility__ ("hidden"))); 55#endif 56 57namespace { 58 59static struct RegisterJIT { 60 RegisterJIT() { JIT::Register(); } 61} JITRegistrator; 62 63} 64 65extern "C" void LLVMLinkInJIT() { 66} 67 68 69#if defined(__GNUC__) && !defined(__ARM__EABI__) 70 71// libgcc defines the __register_frame function to dynamically register new 72// dwarf frames for exception handling. This functionality is not portable 73// across compilers and is only provided by GCC. We use the __register_frame 74// function here so that code generated by the JIT cooperates with the unwinding 75// runtime of libgcc. When JITting with exception handling enable, LLVM 76// generates dwarf frames and registers it to libgcc with __register_frame. 77// 78// The __register_frame function works with Linux. 79// 80// Unfortunately, this functionality seems to be in libgcc after the unwinding 81// library of libgcc for darwin was written. The code for darwin overwrites the 82// value updated by __register_frame with a value fetched with "keymgr". 83// "keymgr" is an obsolete functionality, which should be rewritten some day. 84// In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we 85// need a workaround in LLVM which uses the "keymgr" to dynamically modify the 86// values of an opaque key, used by libgcc to find dwarf tables. 87 88extern "C" void __register_frame(void*); 89 90#if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050 91# define USE_KEYMGR 1 92#else 93# define USE_KEYMGR 0 94#endif 95 96#if USE_KEYMGR 97 98namespace { 99 100// LibgccObject - This is the structure defined in libgcc. There is no #include 101// provided for this structure, so we also define it here. libgcc calls it 102// "struct object". The structure is undocumented in libgcc. 103struct LibgccObject { 104 void *unused1; 105 void *unused2; 106 void *unused3; 107 108 /// frame - Pointer to the exception table. 109 void *frame; 110 111 /// encoding - The encoding of the object? 112 union { 113 struct { 114 unsigned long sorted : 1; 115 unsigned long from_array : 1; 116 unsigned long mixed_encoding : 1; 117 unsigned long encoding : 8; 118 unsigned long count : 21; 119 } b; 120 size_t i; 121 } encoding; 122 123 /// fde_end - libgcc defines this field only if some macro is defined. We 124 /// include this field even if it may not there, to make libgcc happy. 125 char *fde_end; 126 127 /// next - At least we know it's a chained list! 128 struct LibgccObject *next; 129}; 130 131// "kemgr" stuff. Apparently, all frame tables are stored there. 132extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *); 133extern "C" void *_keymgr_get_and_lock_processwide_ptr(int); 134#define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */ 135 136/// LibgccObjectInfo - libgcc defines this struct as km_object_info. It 137/// probably contains all dwarf tables that are loaded. 138struct LibgccObjectInfo { 139 140 /// seenObjects - LibgccObjects already parsed by the unwinding runtime. 141 /// 142 struct LibgccObject* seenObjects; 143 144 /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime. 145 /// 146 struct LibgccObject* unseenObjects; 147 148 unsigned unused[2]; 149}; 150 151/// darwin_register_frame - Since __register_frame does not work with darwin's 152/// libgcc,we provide our own function, which "tricks" libgcc by modifying the 153/// "Dwarf2 object list" key. 154void DarwinRegisterFrame(void* FrameBegin) { 155 // Get the key. 156 LibgccObjectInfo* LOI = (struct LibgccObjectInfo*) 157 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST); 158 assert(LOI && "This should be preallocated by the runtime"); 159 160 // Allocate a new LibgccObject to represent this frame. Deallocation of this 161 // object may be impossible: since darwin code in libgcc was written after 162 // the ability to dynamically register frames, things may crash if we 163 // deallocate it. 164 struct LibgccObject* ob = (struct LibgccObject*) 165 malloc(sizeof(struct LibgccObject)); 166 167 // Do like libgcc for the values of the field. 168 ob->unused1 = (void *)-1; 169 ob->unused2 = 0; 170 ob->unused3 = 0; 171 ob->frame = FrameBegin; 172 ob->encoding.i = 0; 173 ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit; 174 175 // Put the info on both places, as libgcc uses the first or the the second 176 // field. Note that we rely on having two pointers here. If fde_end was a 177 // char, things would get complicated. 178 ob->fde_end = (char*)LOI->unseenObjects; 179 ob->next = LOI->unseenObjects; 180 181 // Update the key's unseenObjects list. 182 LOI->unseenObjects = ob; 183 184 // Finally update the "key". Apparently, libgcc requires it. 185 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, 186 LOI); 187 188} 189 190} 191#endif // __APPLE__ 192#endif // __GNUC__ 193 194/// createJIT - This is the factory method for creating a JIT for the current 195/// machine, it does not fall back to the interpreter. This takes ownership 196/// of the module provider. 197ExecutionEngine *ExecutionEngine::createJIT(ModuleProvider *MP, 198 std::string *ErrorStr, 199 JITMemoryManager *JMM, 200 CodeGenOpt::Level OptLevel, 201 bool GVsWithCode, 202 CodeModel::Model CMM) { 203 return JIT::createJIT(MP, ErrorStr, JMM, OptLevel, GVsWithCode, CMM); 204} 205 206ExecutionEngine *JIT::createJIT(ModuleProvider *MP, 207 std::string *ErrorStr, 208 JITMemoryManager *JMM, 209 CodeGenOpt::Level OptLevel, 210 bool GVsWithCode, 211 CodeModel::Model CMM) { 212 // Make sure we can resolve symbols in the program as well. The zero arg 213 // to the function tells DynamicLibrary to load the program, not a library. 214 if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr)) 215 return 0; 216 217 // Pick a target either via -march or by guessing the native arch. 218 TargetMachine *TM = JIT::selectTarget(MP, ErrorStr); 219 if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0; 220 TM->setCodeModel(CMM); 221 222 // If the target supports JIT code generation, create a the JIT. 223 if (TargetJITInfo *TJ = TM->getJITInfo()) { 224 return new JIT(MP, *TM, *TJ, JMM, OptLevel, GVsWithCode); 225 } else { 226 if (ErrorStr) 227 *ErrorStr = "target does not support JIT code generation"; 228 return 0; 229 } 230} 231 232JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji, 233 JITMemoryManager *JMM, CodeGenOpt::Level OptLevel, bool GVsWithCode) 234 : ExecutionEngine(MP), TM(tm), TJI(tji), AllocateGVsWithCode(GVsWithCode) { 235 setTargetData(TM.getTargetData()); 236 237 jitstate = new JITState(MP); 238 239 // Initialize JCE 240 JCE = createEmitter(*this, JMM, TM); 241 242 // Add target data 243 MutexGuard locked(lock); 244 FunctionPassManager &PM = jitstate->getPM(locked); 245 PM.add(new TargetData(*TM.getTargetData())); 246 247 // Turn the machine code intermediate representation into bytes in memory that 248 // may be executed. 249 if (TM.addPassesToEmitMachineCode(PM, *JCE, OptLevel)) { 250 llvm_report_error("Target does not support machine code emission!"); 251 } 252 253 // Register routine for informing unwinding runtime about new EH frames 254#if defined(__GNUC__) && !defined(__ARM_EABI__) 255#if USE_KEYMGR 256 struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*) 257 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST); 258 259 // The key is created on demand, and libgcc creates it the first time an 260 // exception occurs. Since we need the key to register frames, we create 261 // it now. 262 if (!LOI) 263 LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1); 264 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI); 265 InstallExceptionTableRegister(DarwinRegisterFrame); 266#else 267 InstallExceptionTableRegister(__register_frame); 268#endif // __APPLE__ 269#endif // __GNUC__ 270 271 // Initialize passes. 272 PM.doInitialization(); 273} 274 275JIT::~JIT() { 276 delete jitstate; 277 delete JCE; 278 delete &TM; 279} 280 281/// addModuleProvider - Add a new ModuleProvider to the JIT. If we previously 282/// removed the last ModuleProvider, we need re-initialize jitstate with a valid 283/// ModuleProvider. 284void JIT::addModuleProvider(ModuleProvider *MP) { 285 MutexGuard locked(lock); 286 287 if (Modules.empty()) { 288 assert(!jitstate && "jitstate should be NULL if Modules vector is empty!"); 289 290 jitstate = new JITState(MP); 291 292 FunctionPassManager &PM = jitstate->getPM(locked); 293 PM.add(new TargetData(*TM.getTargetData())); 294 295 // Turn the machine code intermediate representation into bytes in memory 296 // that may be executed. 297 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) { 298 llvm_report_error("Target does not support machine code emission!"); 299 } 300 301 // Initialize passes. 302 PM.doInitialization(); 303 } 304 305 ExecutionEngine::addModuleProvider(MP); 306} 307 308/// removeModuleProvider - If we are removing the last ModuleProvider, 309/// invalidate the jitstate since the PassManager it contains references a 310/// released ModuleProvider. 311Module *JIT::removeModuleProvider(ModuleProvider *MP, std::string *E) { 312 Module *result = ExecutionEngine::removeModuleProvider(MP, E); 313 314 MutexGuard locked(lock); 315 316 if (jitstate->getMP() == MP) { 317 delete jitstate; 318 jitstate = 0; 319 } 320 321 if (!jitstate && !Modules.empty()) { 322 jitstate = new JITState(Modules[0]); 323 324 FunctionPassManager &PM = jitstate->getPM(locked); 325 PM.add(new TargetData(*TM.getTargetData())); 326 327 // Turn the machine code intermediate representation into bytes in memory 328 // that may be executed. 329 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) { 330 llvm_report_error("Target does not support machine code emission!"); 331 } 332 333 // Initialize passes. 334 PM.doInitialization(); 335 } 336 return result; 337} 338 339/// deleteModuleProvider - Remove a ModuleProvider from the list of modules, 340/// and deletes the ModuleProvider and owned Module. Avoids materializing 341/// the underlying module. 342void JIT::deleteModuleProvider(ModuleProvider *MP, std::string *E) { 343 ExecutionEngine::deleteModuleProvider(MP, E); 344 345 MutexGuard locked(lock); 346 347 if (jitstate->getMP() == MP) { 348 delete jitstate; 349 jitstate = 0; 350 } 351 352 if (!jitstate && !Modules.empty()) { 353 jitstate = new JITState(Modules[0]); 354 355 FunctionPassManager &PM = jitstate->getPM(locked); 356 PM.add(new TargetData(*TM.getTargetData())); 357 358 // Turn the machine code intermediate representation into bytes in memory 359 // that may be executed. 360 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) { 361 llvm_report_error("Target does not support machine code emission!"); 362 } 363 364 // Initialize passes. 365 PM.doInitialization(); 366 } 367} 368 369/// run - Start execution with the specified function and arguments. 370/// 371GenericValue JIT::runFunction(Function *F, 372 const std::vector<GenericValue> &ArgValues) { 373 assert(F && "Function *F was null at entry to run()"); 374 375 void *FPtr = getPointerToFunction(F); 376 assert(FPtr && "Pointer to fn's code was null after getPointerToFunction"); 377 const FunctionType *FTy = F->getFunctionType(); 378 const Type *RetTy = FTy->getReturnType(); 379 380 assert((FTy->getNumParams() == ArgValues.size() || 381 (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) && 382 "Wrong number of arguments passed into function!"); 383 assert(FTy->getNumParams() == ArgValues.size() && 384 "This doesn't support passing arguments through varargs (yet)!"); 385 386 // Handle some common cases first. These cases correspond to common `main' 387 // prototypes. 388 if (RetTy == Type::getInt32Ty(F->getContext()) || 389 RetTy == Type::getVoidTy(F->getContext())) { 390 switch (ArgValues.size()) { 391 case 3: 392 if (FTy->getParamType(0) == Type::getInt32Ty(F->getContext()) && 393 isa<PointerType>(FTy->getParamType(1)) && 394 isa<PointerType>(FTy->getParamType(2))) { 395 int (*PF)(int, char **, const char **) = 396 (int(*)(int, char **, const char **))(intptr_t)FPtr; 397 398 // Call the function. 399 GenericValue rv; 400 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), 401 (char **)GVTOP(ArgValues[1]), 402 (const char **)GVTOP(ArgValues[2]))); 403 return rv; 404 } 405 break; 406 case 2: 407 if (FTy->getParamType(0) == Type::getInt32Ty(F->getContext()) && 408 isa<PointerType>(FTy->getParamType(1))) { 409 int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr; 410 411 // Call the function. 412 GenericValue rv; 413 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), 414 (char **)GVTOP(ArgValues[1]))); 415 return rv; 416 } 417 break; 418 case 1: 419 if (FTy->getNumParams() == 1 && 420 FTy->getParamType(0) == Type::getInt32Ty(F->getContext())) { 421 GenericValue rv; 422 int (*PF)(int) = (int(*)(int))(intptr_t)FPtr; 423 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue())); 424 return rv; 425 } 426 break; 427 } 428 } 429 430 // Handle cases where no arguments are passed first. 431 if (ArgValues.empty()) { 432 GenericValue rv; 433 switch (RetTy->getTypeID()) { 434 default: llvm_unreachable("Unknown return type for function call!"); 435 case Type::IntegerTyID: { 436 unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth(); 437 if (BitWidth == 1) 438 rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)()); 439 else if (BitWidth <= 8) 440 rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)()); 441 else if (BitWidth <= 16) 442 rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)()); 443 else if (BitWidth <= 32) 444 rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)()); 445 else if (BitWidth <= 64) 446 rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)()); 447 else 448 llvm_unreachable("Integer types > 64 bits not supported"); 449 return rv; 450 } 451 case Type::VoidTyID: 452 rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)()); 453 return rv; 454 case Type::FloatTyID: 455 rv.FloatVal = ((float(*)())(intptr_t)FPtr)(); 456 return rv; 457 case Type::DoubleTyID: 458 rv.DoubleVal = ((double(*)())(intptr_t)FPtr)(); 459 return rv; 460 case Type::X86_FP80TyID: 461 case Type::FP128TyID: 462 case Type::PPC_FP128TyID: 463 llvm_unreachable("long double not supported yet"); 464 return rv; 465 case Type::PointerTyID: 466 return PTOGV(((void*(*)())(intptr_t)FPtr)()); 467 } 468 } 469 470 // Okay, this is not one of our quick and easy cases. Because we don't have a 471 // full FFI, we have to codegen a nullary stub function that just calls the 472 // function we are interested in, passing in constants for all of the 473 // arguments. Make this function and return. 474 475 // First, create the function. 476 FunctionType *STy=FunctionType::get(RetTy, false); 477 Function *Stub = Function::Create(STy, Function::InternalLinkage, "", 478 F->getParent()); 479 480 // Insert a basic block. 481 BasicBlock *StubBB = BasicBlock::Create(F->getContext(), "", Stub); 482 483 // Convert all of the GenericValue arguments over to constants. Note that we 484 // currently don't support varargs. 485 SmallVector<Value*, 8> Args; 486 for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) { 487 Constant *C = 0; 488 const Type *ArgTy = FTy->getParamType(i); 489 const GenericValue &AV = ArgValues[i]; 490 switch (ArgTy->getTypeID()) { 491 default: llvm_unreachable("Unknown argument type for function call!"); 492 case Type::IntegerTyID: 493 C = ConstantInt::get(F->getContext(), AV.IntVal); 494 break; 495 case Type::FloatTyID: 496 C = ConstantFP::get(F->getContext(), APFloat(AV.FloatVal)); 497 break; 498 case Type::DoubleTyID: 499 C = ConstantFP::get(F->getContext(), APFloat(AV.DoubleVal)); 500 break; 501 case Type::PPC_FP128TyID: 502 case Type::X86_FP80TyID: 503 case Type::FP128TyID: 504 C = ConstantFP::get(F->getContext(), APFloat(AV.IntVal)); 505 break; 506 case Type::PointerTyID: 507 void *ArgPtr = GVTOP(AV); 508 if (sizeof(void*) == 4) 509 C = ConstantInt::get(Type::getInt32Ty(F->getContext()), 510 (int)(intptr_t)ArgPtr); 511 else 512 C = ConstantInt::get(Type::getInt64Ty(F->getContext()), 513 (intptr_t)ArgPtr); 514 // Cast the integer to pointer 515 C = ConstantExpr::getIntToPtr(C, ArgTy); 516 break; 517 } 518 Args.push_back(C); 519 } 520 521 CallInst *TheCall = CallInst::Create(F, Args.begin(), Args.end(), 522 "", StubBB); 523 TheCall->setCallingConv(F->getCallingConv()); 524 TheCall->setTailCall(); 525 if (TheCall->getType() != Type::getVoidTy(F->getContext())) 526 // Return result of the call. 527 ReturnInst::Create(F->getContext(), TheCall, StubBB); 528 else 529 ReturnInst::Create(F->getContext(), StubBB); // Just return void. 530 531 // Finally, return the value returned by our nullary stub function. 532 return runFunction(Stub, std::vector<GenericValue>()); 533} 534 535void JIT::RegisterJITEventListener(JITEventListener *L) { 536 if (L == NULL) 537 return; 538 MutexGuard locked(lock); 539 EventListeners.push_back(L); 540} 541void JIT::UnregisterJITEventListener(JITEventListener *L) { 542 if (L == NULL) 543 return; 544 MutexGuard locked(lock); 545 std::vector<JITEventListener*>::reverse_iterator I= 546 std::find(EventListeners.rbegin(), EventListeners.rend(), L); 547 if (I != EventListeners.rend()) { 548 std::swap(*I, EventListeners.back()); 549 EventListeners.pop_back(); 550 } 551} 552void JIT::NotifyFunctionEmitted( 553 const Function &F, 554 void *Code, size_t Size, 555 const JITEvent_EmittedFunctionDetails &Details) { 556 MutexGuard locked(lock); 557 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) { 558 EventListeners[I]->NotifyFunctionEmitted(F, Code, Size, Details); 559 } 560} 561 562void JIT::NotifyFreeingMachineCode(void *OldPtr) { 563 MutexGuard locked(lock); 564 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) { 565 EventListeners[I]->NotifyFreeingMachineCode(OldPtr); 566 } 567} 568 569/// runJITOnFunction - Run the FunctionPassManager full of 570/// just-in-time compilation passes on F, hopefully filling in 571/// GlobalAddress[F] with the address of F's machine code. 572/// 573void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) { 574 MutexGuard locked(lock); 575 576 class MCIListener : public JITEventListener { 577 MachineCodeInfo *const MCI; 578 public: 579 MCIListener(MachineCodeInfo *mci) : MCI(mci) {} 580 virtual void NotifyFunctionEmitted(const Function &, 581 void *Code, size_t Size, 582 const EmittedFunctionDetails &) { 583 MCI->setAddress(Code); 584 MCI->setSize(Size); 585 } 586 }; 587 MCIListener MCIL(MCI); 588 RegisterJITEventListener(&MCIL); 589 590 runJITOnFunctionUnlocked(F, locked); 591 592 UnregisterJITEventListener(&MCIL); 593} 594 595void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) { 596 static bool isAlreadyCodeGenerating = false; 597 assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!"); 598 599 // JIT the function 600 isAlreadyCodeGenerating = true; 601 jitstate->getPM(locked).run(*F); 602 isAlreadyCodeGenerating = false; 603 604 // If the function referred to another function that had not yet been 605 // read from bitcode, and we are jitting non-lazily, emit it now. 606 while (!jitstate->getPendingFunctions(locked).empty()) { 607 Function *PF = jitstate->getPendingFunctions(locked).back(); 608 jitstate->getPendingFunctions(locked).pop_back(); 609 610 // JIT the function 611 isAlreadyCodeGenerating = true; 612 jitstate->getPM(locked).run(*PF); 613 isAlreadyCodeGenerating = false; 614 615 // Now that the function has been jitted, ask the JITEmitter to rewrite 616 // the stub with real address of the function. 617 updateFunctionStub(PF); 618 } 619} 620 621/// getPointerToFunction - This method is used to get the address of the 622/// specified function, compiling it if neccesary. 623/// 624void *JIT::getPointerToFunction(Function *F) { 625 626 if (void *Addr = getPointerToGlobalIfAvailable(F)) 627 return Addr; // Check if function already code gen'd 628 629 MutexGuard locked(lock); 630 631 // Now that this thread owns the lock, check if another thread has already 632 // code gen'd the function. 633 if (void *Addr = getPointerToGlobalIfAvailable(F)) 634 return Addr; 635 636 // Make sure we read in the function if it exists in this Module. 637 if (F->hasNotBeenReadFromBitcode()) { 638 // Determine the module provider this function is provided by. 639 Module *M = F->getParent(); 640 ModuleProvider *MP = 0; 641 for (unsigned i = 0, e = Modules.size(); i != e; ++i) { 642 if (Modules[i]->getModule() == M) { 643 MP = Modules[i]; 644 break; 645 } 646 } 647 assert(MP && "Function isn't in a module we know about!"); 648 649 std::string ErrorMsg; 650 if (MP->materializeFunction(F, &ErrorMsg)) { 651 llvm_report_error("Error reading function '" + F->getName()+ 652 "' from bitcode file: " + ErrorMsg); 653 } 654 655 // Now retry to get the address. 656 if (void *Addr = getPointerToGlobalIfAvailable(F)) 657 return Addr; 658 } 659 660 if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) { 661 bool AbortOnFailure = !F->hasExternalWeakLinkage(); 662 void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure); 663 addGlobalMapping(F, Addr); 664 return Addr; 665 } 666 667 runJITOnFunctionUnlocked(F, locked); 668 669 void *Addr = getPointerToGlobalIfAvailable(F); 670 assert(Addr && "Code generation didn't add function to GlobalAddress table!"); 671 return Addr; 672} 673 674/// getOrEmitGlobalVariable - Return the address of the specified global 675/// variable, possibly emitting it to memory if needed. This is used by the 676/// Emitter. 677void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) { 678 MutexGuard locked(lock); 679 680 void *Ptr = getPointerToGlobalIfAvailable(GV); 681 if (Ptr) return Ptr; 682 683 // If the global is external, just remember the address. 684 if (GV->isDeclaration()) { 685#if HAVE___DSO_HANDLE 686 if (GV->getName() == "__dso_handle") 687 return (void*)&__dso_handle; 688#endif 689 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName()); 690 if (Ptr == 0) { 691 llvm_report_error("Could not resolve external global address: " 692 +GV->getName()); 693 } 694 addGlobalMapping(GV, Ptr); 695 } else { 696 // If the global hasn't been emitted to memory yet, allocate space and 697 // emit it into memory. 698 Ptr = getMemoryForGV(GV); 699 addGlobalMapping(GV, Ptr); 700 EmitGlobalVariable(GV); // Initialize the variable. 701 } 702 return Ptr; 703} 704 705/// recompileAndRelinkFunction - This method is used to force a function 706/// which has already been compiled, to be compiled again, possibly 707/// after it has been modified. Then the entry to the old copy is overwritten 708/// with a branch to the new copy. If there was no old copy, this acts 709/// just like JIT::getPointerToFunction(). 710/// 711void *JIT::recompileAndRelinkFunction(Function *F) { 712 void *OldAddr = getPointerToGlobalIfAvailable(F); 713 714 // If it's not already compiled there is no reason to patch it up. 715 if (OldAddr == 0) { return getPointerToFunction(F); } 716 717 // Delete the old function mapping. 718 addGlobalMapping(F, 0); 719 720 // Recodegen the function 721 runJITOnFunction(F); 722 723 // Update state, forward the old function to the new function. 724 void *Addr = getPointerToGlobalIfAvailable(F); 725 assert(Addr && "Code generation didn't add function to GlobalAddress table!"); 726 TJI.replaceMachineCodeForFunction(OldAddr, Addr); 727 return Addr; 728} 729 730/// getMemoryForGV - This method abstracts memory allocation of global 731/// variable so that the JIT can allocate thread local variables depending 732/// on the target. 733/// 734char* JIT::getMemoryForGV(const GlobalVariable* GV) { 735 char *Ptr; 736 737 // GlobalVariable's which are not "constant" will cause trouble in a server 738 // situation. It's returned in the same block of memory as code which may 739 // not be writable. 740 if (isGVCompilationDisabled() && !GV->isConstant()) { 741 llvm_report_error("Compilation of non-internal GlobalValue is disabled!"); 742 } 743 744 // Some applications require globals and code to live together, so they may 745 // be allocated into the same buffer, but in general globals are allocated 746 // through the memory manager which puts them near the code but not in the 747 // same buffer. 748 const Type *GlobalType = GV->getType()->getElementType(); 749 size_t S = getTargetData()->getTypeAllocSize(GlobalType); 750 size_t A = getTargetData()->getPreferredAlignment(GV); 751 if (GV->isThreadLocal()) { 752 MutexGuard locked(lock); 753 Ptr = TJI.allocateThreadLocalMemory(S); 754 } else if (TJI.allocateSeparateGVMemory()) { 755 if (A <= 8) { 756 Ptr = (char*)malloc(S); 757 } else { 758 // Allocate S+A bytes of memory, then use an aligned pointer within that 759 // space. 760 Ptr = (char*)malloc(S+A); 761 unsigned MisAligned = ((intptr_t)Ptr & (A-1)); 762 Ptr = Ptr + (MisAligned ? (A-MisAligned) : 0); 763 } 764 } else if (AllocateGVsWithCode) { 765 Ptr = (char*)JCE->allocateSpace(S, A); 766 } else { 767 Ptr = (char*)JCE->allocateGlobal(S, A); 768 } 769 return Ptr; 770} 771 772void JIT::addPendingFunction(Function *F) { 773 MutexGuard locked(lock); 774 jitstate->getPendingFunctions(locked).push_back(F); 775} 776 777 778JITEventListener::~JITEventListener() {} 779