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/ADT/SmallPtrSet.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/ManagedStatic.h"
32 #include "llvm/Support/MutexGuard.h"
33 #include "llvm/System/DynamicLibrary.h"
34 #include "llvm/Config/config.h"
35
36 using namespace llvm;
37
38 #ifdef __APPLE__
39 // Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
40 // of atexit). It passes the address of linker generated symbol __dso_handle
41 // to the function.
42 // This configuration change happened at version 5330.
43 # include <AvailabilityMacros.h>
44 # if defined(MAC_OS_X_VERSION_10_4) && \
45 ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
46 (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
47 __APPLE_CC__ >= 5330))
48 # ifndef HAVE___DSO_HANDLE
49 # define HAVE___DSO_HANDLE 1
50 # endif
51 # endif
52 #endif
53
54 #if HAVE___DSO_HANDLE
55 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
56 #endif
57
58 namespace {
59
60 static struct RegisterJIT {
RegisterJIT__anonb02dc7520111::RegisterJIT61 RegisterJIT() { JIT::Register(); }
62 } JITRegistrator;
63
64 }
65
LLVMLinkInJIT()66 extern "C" void LLVMLinkInJIT() {
67 }
68
69
70 #if defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__USING_SJLJ_EXCEPTIONS__)
71
72 // libgcc defines the __register_frame function to dynamically register new
73 // dwarf frames for exception handling. This functionality is not portable
74 // across compilers and is only provided by GCC. We use the __register_frame
75 // function here so that code generated by the JIT cooperates with the unwinding
76 // runtime of libgcc. When JITting with exception handling enable, LLVM
77 // generates dwarf frames and registers it to libgcc with __register_frame.
78 //
79 // The __register_frame function works with Linux.
80 //
81 // Unfortunately, this functionality seems to be in libgcc after the unwinding
82 // library of libgcc for darwin was written. The code for darwin overwrites the
83 // value updated by __register_frame with a value fetched with "keymgr".
84 // "keymgr" is an obsolete functionality, which should be rewritten some day.
85 // In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we
86 // need a workaround in LLVM which uses the "keymgr" to dynamically modify the
87 // values of an opaque key, used by libgcc to find dwarf tables.
88
89 extern "C" void __register_frame(void*);
90
91 #if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050
92 # define USE_KEYMGR 1
93 #else
94 # define USE_KEYMGR 0
95 #endif
96
97 #if USE_KEYMGR
98
99 namespace {
100
101 // LibgccObject - This is the structure defined in libgcc. There is no #include
102 // provided for this structure, so we also define it here. libgcc calls it
103 // "struct object". The structure is undocumented in libgcc.
104 struct LibgccObject {
105 void *unused1;
106 void *unused2;
107 void *unused3;
108
109 /// frame - Pointer to the exception table.
110 void *frame;
111
112 /// encoding - The encoding of the object?
113 union {
114 struct {
115 unsigned long sorted : 1;
116 unsigned long from_array : 1;
117 unsigned long mixed_encoding : 1;
118 unsigned long encoding : 8;
119 unsigned long count : 21;
120 } b;
121 size_t i;
122 } encoding;
123
124 /// fde_end - libgcc defines this field only if some macro is defined. We
125 /// include this field even if it may not there, to make libgcc happy.
126 char *fde_end;
127
128 /// next - At least we know it's a chained list!
129 struct LibgccObject *next;
130 };
131
132 // "kemgr" stuff. Apparently, all frame tables are stored there.
133 extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *);
134 extern "C" void *_keymgr_get_and_lock_processwide_ptr(int);
135 #define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */
136
137 /// LibgccObjectInfo - libgcc defines this struct as km_object_info. It
138 /// probably contains all dwarf tables that are loaded.
139 struct LibgccObjectInfo {
140
141 /// seenObjects - LibgccObjects already parsed by the unwinding runtime.
142 ///
143 struct LibgccObject* seenObjects;
144
145 /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime.
146 ///
147 struct LibgccObject* unseenObjects;
148
149 unsigned unused[2];
150 };
151
152 /// darwin_register_frame - Since __register_frame does not work with darwin's
153 /// libgcc,we provide our own function, which "tricks" libgcc by modifying the
154 /// "Dwarf2 object list" key.
DarwinRegisterFrame(void * FrameBegin)155 void DarwinRegisterFrame(void* FrameBegin) {
156 // Get the key.
157 LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
158 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
159 assert(LOI && "This should be preallocated by the runtime");
160
161 // Allocate a new LibgccObject to represent this frame. Deallocation of this
162 // object may be impossible: since darwin code in libgcc was written after
163 // the ability to dynamically register frames, things may crash if we
164 // deallocate it.
165 struct LibgccObject* ob = (struct LibgccObject*)
166 malloc(sizeof(struct LibgccObject));
167
168 // Do like libgcc for the values of the field.
169 ob->unused1 = (void *)-1;
170 ob->unused2 = 0;
171 ob->unused3 = 0;
172 ob->frame = FrameBegin;
173 ob->encoding.i = 0;
174 ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit;
175
176 // Put the info on both places, as libgcc uses the first or the second
177 // field. Note that we rely on having two pointers here. If fde_end was a
178 // char, things would get complicated.
179 ob->fde_end = (char*)LOI->unseenObjects;
180 ob->next = LOI->unseenObjects;
181
182 // Update the key's unseenObjects list.
183 LOI->unseenObjects = ob;
184
185 // Finally update the "key". Apparently, libgcc requires it.
186 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
187 LOI);
188
189 }
190
191 }
192 #endif // __APPLE__
193 #endif // __GNUC__
194
195 /// createJIT - This is the factory method for creating a JIT for the current
196 /// machine, it does not fall back to the interpreter. This takes ownership
197 /// of the module.
createJIT(Module * M,std::string * ErrorStr,JITMemoryManager * JMM,CodeGenOpt::Level OptLevel,bool GVsWithCode,CodeModel::Model CMM)198 ExecutionEngine *ExecutionEngine::createJIT(Module *M,
199 std::string *ErrorStr,
200 JITMemoryManager *JMM,
201 CodeGenOpt::Level OptLevel,
202 bool GVsWithCode,
203 CodeModel::Model CMM) {
204 // Use the defaults for extra parameters. Users can use EngineBuilder to
205 // set them.
206 StringRef MArch = "";
207 StringRef MCPU = "";
208 SmallVector<std::string, 1> MAttrs;
209 return JIT::createJIT(M, ErrorStr, JMM, OptLevel, GVsWithCode, CMM,
210 MArch, MCPU, MAttrs);
211 }
212
createJIT(Module * M,std::string * ErrorStr,JITMemoryManager * JMM,CodeGenOpt::Level OptLevel,bool GVsWithCode,CodeModel::Model CMM,StringRef MArch,StringRef MCPU,const SmallVectorImpl<std::string> & MAttrs)213 ExecutionEngine *JIT::createJIT(Module *M,
214 std::string *ErrorStr,
215 JITMemoryManager *JMM,
216 CodeGenOpt::Level OptLevel,
217 bool GVsWithCode,
218 CodeModel::Model CMM,
219 StringRef MArch,
220 StringRef MCPU,
221 const SmallVectorImpl<std::string>& MAttrs) {
222 // Try to register the program as a source of symbols to resolve against.
223 sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
224 /* CLAMAV LOCAL: no dlopen */
225 // if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr))
226 // return 0;
227
228 // Pick a target either via -march or by guessing the native arch.
229 TargetMachine *TM = JIT::selectTarget(M, MArch, MCPU, MAttrs, ErrorStr);
230 if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0;
231 TM->setCodeModel(CMM);
232
233 // If the target supports JIT code generation, create a the JIT.
234 if (TargetJITInfo *TJ = TM->getJITInfo()) {
235 return new JIT(M, *TM, *TJ, JMM, OptLevel, GVsWithCode);
236 } else {
237 if (ErrorStr)
238 *ErrorStr = "target does not support JIT code generation";
239 return 0;
240 }
241 }
242
243 namespace {
244 /// This class supports the global getPointerToNamedFunction(), which allows
245 /// bugpoint or gdb users to search for a function by name without any context.
246 class JitPool {
247 SmallPtrSet<JIT*, 1> JITs; // Optimize for process containing just 1 JIT.
248 mutable sys::Mutex Lock;
249 public:
Add(JIT * jit)250 void Add(JIT *jit) {
251 MutexGuard guard(Lock);
252 JITs.insert(jit);
253 }
Remove(JIT * jit)254 void Remove(JIT *jit) {
255 MutexGuard guard(Lock);
256 JITs.erase(jit);
257 }
getPointerToNamedFunction(const char * Name) const258 void *getPointerToNamedFunction(const char *Name) const {
259 MutexGuard guard(Lock);
260 assert(JITs.size() != 0 && "No Jit registered");
261 //search function in every instance of JIT
262 for (SmallPtrSet<JIT*, 1>::const_iterator Jit = JITs.begin(),
263 end = JITs.end();
264 Jit != end; ++Jit) {
265 if (Function *F = (*Jit)->FindFunctionNamed(Name))
266 return (*Jit)->getPointerToFunction(F);
267 }
268 // The function is not available : fallback on the first created (will
269 // search in symbol of the current program/library)
270 return (*JITs.begin())->getPointerToNamedFunction(Name);
271 }
272 };
273 ManagedStatic<JitPool> AllJits;
274 }
275 extern "C" {
276 // getPointerToNamedFunction - This function is used as a global wrapper to
277 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
278 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
279 // need to resolve function(s) that are being mis-codegenerated, so we need to
280 // resolve their addresses at runtime, and this is the way to do it.
getPointerToNamedFunction(const char * Name)281 void *getPointerToNamedFunction(const char *Name) {
282 return AllJits->getPointerToNamedFunction(Name);
283 }
284 }
285
JIT(Module * M,TargetMachine & tm,TargetJITInfo & tji,JITMemoryManager * JMM,CodeGenOpt::Level OptLevel,bool GVsWithCode)286 JIT::JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji,
287 JITMemoryManager *JMM, CodeGenOpt::Level OptLevel, bool GVsWithCode)
288 : ExecutionEngine(M), TM(tm), TJI(tji), AllocateGVsWithCode(GVsWithCode),
289 isAlreadyCodeGenerating(false) {
290 setTargetData(TM.getTargetData());
291
292 jitstate = new JITState(M);
293
294 // Initialize JCE
295 JCE = createEmitter(*this, JMM, TM);
296
297 // Register in global list of all JITs.
298 AllJits->Add(this);
299
300 // Add target data
301 MutexGuard locked(lock);
302 FunctionPassManager &PM = jitstate->getPM(locked);
303 PM.add(new TargetData(*TM.getTargetData()));
304
305 // Turn the machine code intermediate representation into bytes in memory that
306 // may be executed.
307 if (TM.addPassesToEmitMachineCode(PM, *JCE, OptLevel)) {
308 report_fatal_error("Target does not support machine code emission!");
309 }
310
311 // Register routine for informing unwinding runtime about new EH frames
312 #if defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__USING_SJLJ_EXCEPTIONS__)
313 #if USE_KEYMGR
314 struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
315 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
316
317 // The key is created on demand, and libgcc creates it the first time an
318 // exception occurs. Since we need the key to register frames, we create
319 // it now.
320 if (!LOI)
321 LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1);
322 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI);
323 InstallExceptionTableRegister(DarwinRegisterFrame);
324 #else
325 InstallExceptionTableRegister(__register_frame);
326 #endif // __APPLE__
327 #endif // __GNUC__
328
329 // Initialize passes.
330 PM.doInitialization();
331 }
332
~JIT()333 JIT::~JIT() {
334 AllJits->Remove(this);
335 delete jitstate;
336 delete JCE;
337 delete &TM;
338 }
339
340 /// addModule - Add a new Module to the JIT. If we previously removed the last
341 /// Module, we need re-initialize jitstate with a valid Module.
addModule(Module * M)342 void JIT::addModule(Module *M) {
343 MutexGuard locked(lock);
344
345 if (Modules.empty()) {
346 assert(!jitstate && "jitstate should be NULL if Modules vector is empty!");
347
348 jitstate = new JITState(M);
349
350 FunctionPassManager &PM = jitstate->getPM(locked);
351 PM.add(new TargetData(*TM.getTargetData()));
352
353 // Turn the machine code intermediate representation into bytes in memory
354 // that may be executed.
355 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
356 report_fatal_error("Target does not support machine code emission!");
357 }
358
359 // Initialize passes.
360 PM.doInitialization();
361 }
362
363 ExecutionEngine::addModule(M);
364 }
365
366 /// removeModule - If we are removing the last Module, invalidate the jitstate
367 /// since the PassManager it contains references a released Module.
removeModule(Module * M)368 bool JIT::removeModule(Module *M) {
369 bool result = ExecutionEngine::removeModule(M);
370
371 MutexGuard locked(lock);
372
373 if (jitstate->getModule() == M) {
374 delete jitstate;
375 jitstate = 0;
376 }
377
378 if (!jitstate && !Modules.empty()) {
379 jitstate = new JITState(Modules[0]);
380
381 FunctionPassManager &PM = jitstate->getPM(locked);
382 PM.add(new TargetData(*TM.getTargetData()));
383
384 // Turn the machine code intermediate representation into bytes in memory
385 // that may be executed.
386 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
387 report_fatal_error("Target does not support machine code emission!");
388 }
389
390 // Initialize passes.
391 PM.doInitialization();
392 }
393 return result;
394 }
395
396 /// run - Start execution with the specified function and arguments.
397 ///
runFunction(Function * F,const std::vector<GenericValue> & ArgValues)398 GenericValue JIT::runFunction(Function *F,
399 const std::vector<GenericValue> &ArgValues) {
400 assert(F && "Function *F was null at entry to run()");
401
402 void *FPtr = getPointerToFunction(F);
403 assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
404 const FunctionType *FTy = F->getFunctionType();
405 const Type *RetTy = FTy->getReturnType();
406
407 assert((FTy->getNumParams() == ArgValues.size() ||
408 (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
409 "Wrong number of arguments passed into function!");
410 assert(FTy->getNumParams() == ArgValues.size() &&
411 "This doesn't support passing arguments through varargs (yet)!");
412
413 // Handle some common cases first. These cases correspond to common `main'
414 // prototypes.
415 if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
416 switch (ArgValues.size()) {
417 case 3:
418 if (FTy->getParamType(0)->isIntegerTy(32) &&
419 FTy->getParamType(1)->isPointerTy() &&
420 FTy->getParamType(2)->isPointerTy()) {
421 int (*PF)(int, char **, const char **) =
422 (int(*)(int, char **, const char **))(intptr_t)FPtr;
423
424 // Call the function.
425 GenericValue rv;
426 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
427 (char **)GVTOP(ArgValues[1]),
428 (const char **)GVTOP(ArgValues[2])));
429 return rv;
430 }
431 break;
432 case 2:
433 if (FTy->getParamType(0)->isIntegerTy(32) &&
434 FTy->getParamType(1)->isPointerTy()) {
435 int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
436
437 // Call the function.
438 GenericValue rv;
439 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
440 (char **)GVTOP(ArgValues[1])));
441 return rv;
442 }
443 break;
444 case 1:
445 if (FTy->getNumParams() == 1 &&
446 FTy->getParamType(0)->isIntegerTy(32)) {
447 GenericValue rv;
448 int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
449 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
450 return rv;
451 }
452 break;
453 }
454 }
455
456 // Handle cases where no arguments are passed first.
457 if (ArgValues.empty()) {
458 GenericValue rv;
459 switch (RetTy->getTypeID()) {
460 default: llvm_unreachable("Unknown return type for function call!");
461 case Type::IntegerTyID: {
462 unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
463 if (BitWidth == 1)
464 rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
465 else if (BitWidth <= 8)
466 rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
467 else if (BitWidth <= 16)
468 rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
469 else if (BitWidth <= 32)
470 rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
471 else if (BitWidth <= 64)
472 rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
473 else
474 llvm_unreachable("Integer types > 64 bits not supported");
475 return rv;
476 }
477 case Type::VoidTyID:
478 rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
479 return rv;
480 case Type::FloatTyID:
481 rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
482 return rv;
483 case Type::DoubleTyID:
484 rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
485 return rv;
486 case Type::X86_FP80TyID:
487 case Type::FP128TyID:
488 case Type::PPC_FP128TyID:
489 llvm_unreachable("long double not supported yet");
490 return rv;
491 case Type::PointerTyID:
492 return PTOGV(((void*(*)())(intptr_t)FPtr)());
493 }
494 }
495
496 // Okay, this is not one of our quick and easy cases. Because we don't have a
497 // full FFI, we have to codegen a nullary stub function that just calls the
498 // function we are interested in, passing in constants for all of the
499 // arguments. Make this function and return.
500
501 // First, create the function.
502 FunctionType *STy=FunctionType::get(RetTy, false);
503 Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
504 F->getParent());
505
506 // Insert a basic block.
507 BasicBlock *StubBB = BasicBlock::Create(F->getContext(), "", Stub);
508
509 // Convert all of the GenericValue arguments over to constants. Note that we
510 // currently don't support varargs.
511 SmallVector<Value*, 8> Args;
512 for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
513 Constant *C = 0;
514 const Type *ArgTy = FTy->getParamType(i);
515 const GenericValue &AV = ArgValues[i];
516 switch (ArgTy->getTypeID()) {
517 default: llvm_unreachable("Unknown argument type for function call!");
518 case Type::IntegerTyID:
519 C = ConstantInt::get(F->getContext(), AV.IntVal);
520 break;
521 case Type::FloatTyID:
522 C = ConstantFP::get(F->getContext(), APFloat(AV.FloatVal));
523 break;
524 case Type::DoubleTyID:
525 C = ConstantFP::get(F->getContext(), APFloat(AV.DoubleVal));
526 break;
527 case Type::PPC_FP128TyID:
528 case Type::X86_FP80TyID:
529 case Type::FP128TyID:
530 C = ConstantFP::get(F->getContext(), APFloat(AV.IntVal));
531 break;
532 case Type::PointerTyID:
533 void *ArgPtr = GVTOP(AV);
534 if (sizeof(void*) == 4)
535 C = ConstantInt::get(Type::getInt32Ty(F->getContext()),
536 (int)(intptr_t)ArgPtr);
537 else
538 C = ConstantInt::get(Type::getInt64Ty(F->getContext()),
539 (intptr_t)ArgPtr);
540 // Cast the integer to pointer
541 C = ConstantExpr::getIntToPtr(C, ArgTy);
542 break;
543 }
544 Args.push_back(C);
545 }
546
547 CallInst *TheCall = CallInst::Create(F, Args.begin(), Args.end(),
548 "", StubBB);
549 TheCall->setCallingConv(F->getCallingConv());
550 TheCall->setTailCall();
551 if (!TheCall->getType()->isVoidTy())
552 // Return result of the call.
553 ReturnInst::Create(F->getContext(), TheCall, StubBB);
554 else
555 ReturnInst::Create(F->getContext(), StubBB); // Just return void.
556
557 // Finally, call our nullary stub function.
558 GenericValue Result = runFunction(Stub, std::vector<GenericValue>());
559 // Erase it, since no other function can have a reference to it.
560 Stub->eraseFromParent();
561 // And return the result.
562 return Result;
563 }
564
RegisterJITEventListener(JITEventListener * L)565 void JIT::RegisterJITEventListener(JITEventListener *L) {
566 if (L == NULL)
567 return;
568 MutexGuard locked(lock);
569 EventListeners.push_back(L);
570 }
UnregisterJITEventListener(JITEventListener * L)571 void JIT::UnregisterJITEventListener(JITEventListener *L) {
572 if (L == NULL)
573 return;
574 MutexGuard locked(lock);
575 std::vector<JITEventListener*>::reverse_iterator I=
576 std::find(EventListeners.rbegin(), EventListeners.rend(), L);
577 if (I != EventListeners.rend()) {
578 std::swap(*I, EventListeners.back());
579 EventListeners.pop_back();
580 }
581 }
NotifyFunctionEmitted(const Function & F,void * Code,size_t Size,const JITEvent_EmittedFunctionDetails & Details)582 void JIT::NotifyFunctionEmitted(
583 const Function &F,
584 void *Code, size_t Size,
585 const JITEvent_EmittedFunctionDetails &Details) {
586 MutexGuard locked(lock);
587 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
588 EventListeners[I]->NotifyFunctionEmitted(F, Code, Size, Details);
589 }
590 }
591
NotifyFreeingMachineCode(void * OldPtr)592 void JIT::NotifyFreeingMachineCode(void *OldPtr) {
593 MutexGuard locked(lock);
594 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
595 EventListeners[I]->NotifyFreeingMachineCode(OldPtr);
596 }
597 }
598
599 /// runJITOnFunction - Run the FunctionPassManager full of
600 /// just-in-time compilation passes on F, hopefully filling in
601 /// GlobalAddress[F] with the address of F's machine code.
602 ///
runJITOnFunction(Function * F,MachineCodeInfo * MCI)603 void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) {
604 MutexGuard locked(lock);
605
606 class MCIListener : public JITEventListener {
607 MachineCodeInfo *const MCI;
608 public:
609 MCIListener(MachineCodeInfo *mci) : MCI(mci) {}
610 virtual void NotifyFunctionEmitted(const Function &,
611 void *Code, size_t Size,
612 const EmittedFunctionDetails &) {
613 MCI->setAddress(Code);
614 MCI->setSize(Size);
615 }
616 };
617 MCIListener MCIL(MCI);
618 if (MCI)
619 RegisterJITEventListener(&MCIL);
620
621 runJITOnFunctionUnlocked(F, locked);
622
623 if (MCI)
624 UnregisterJITEventListener(&MCIL);
625 }
626
runJITOnFunctionUnlocked(Function * F,const MutexGuard & locked)627 void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) {
628 assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
629
630 jitTheFunction(F, locked);
631
632 // If the function referred to another function that had not yet been
633 // read from bitcode, and we are jitting non-lazily, emit it now.
634 while (!jitstate->getPendingFunctions(locked).empty()) {
635 Function *PF = jitstate->getPendingFunctions(locked).back();
636 jitstate->getPendingFunctions(locked).pop_back();
637
638 assert(!PF->hasAvailableExternallyLinkage() &&
639 "Externally-defined function should not be in pending list.");
640
641 jitTheFunction(PF, locked);
642
643 // Now that the function has been jitted, ask the JITEmitter to rewrite
644 // the stub with real address of the function.
645 updateFunctionStub(PF);
646 }
647 }
648
jitTheFunction(Function * F,const MutexGuard & locked)649 void JIT::jitTheFunction(Function *F, const MutexGuard &locked) {
650 isAlreadyCodeGenerating = true;
651 jitstate->getPM(locked).run(*F);
652 isAlreadyCodeGenerating = false;
653
654 // clear basic block addresses after this function is done
655 getBasicBlockAddressMap(locked).clear();
656 }
657
658 /// getPointerToFunction - This method is used to get the address of the
659 /// specified function, compiling it if neccesary.
660 ///
getPointerToFunction(Function * F)661 void *JIT::getPointerToFunction(Function *F) {
662
663 if (void *Addr = getPointerToGlobalIfAvailable(F))
664 return Addr; // Check if function already code gen'd
665
666 MutexGuard locked(lock);
667
668 // Now that this thread owns the lock, make sure we read in the function if it
669 // exists in this Module.
670 std::string ErrorMsg;
671 if (F->Materialize(&ErrorMsg)) {
672 report_fatal_error("Error reading function '" + F->getName()+
673 "' from bitcode file: " + ErrorMsg);
674 }
675
676 // ... and check if another thread has already code gen'd the function.
677 if (void *Addr = getPointerToGlobalIfAvailable(F))
678 return Addr;
679
680 if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
681 bool AbortOnFailure = !F->hasExternalWeakLinkage();
682 void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
683 addGlobalMapping(F, Addr);
684 return Addr;
685 }
686
687 runJITOnFunctionUnlocked(F, locked);
688
689 void *Addr = getPointerToGlobalIfAvailable(F);
690 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
691 return Addr;
692 }
693
addPointerToBasicBlock(const BasicBlock * BB,void * Addr)694 void JIT::addPointerToBasicBlock(const BasicBlock *BB, void *Addr) {
695 MutexGuard locked(lock);
696
697 BasicBlockAddressMapTy::iterator I =
698 getBasicBlockAddressMap(locked).find(BB);
699 if (I == getBasicBlockAddressMap(locked).end()) {
700 getBasicBlockAddressMap(locked)[BB] = Addr;
701 } else {
702 // ignore repeats: some BBs can be split into few MBBs?
703 }
704 }
705
clearPointerToBasicBlock(const BasicBlock * BB)706 void JIT::clearPointerToBasicBlock(const BasicBlock *BB) {
707 MutexGuard locked(lock);
708 getBasicBlockAddressMap(locked).erase(BB);
709 }
710
getPointerToBasicBlock(BasicBlock * BB)711 void *JIT::getPointerToBasicBlock(BasicBlock *BB) {
712 // make sure it's function is compiled by JIT
713 (void)getPointerToFunction(BB->getParent());
714
715 // resolve basic block address
716 MutexGuard locked(lock);
717
718 BasicBlockAddressMapTy::iterator I =
719 getBasicBlockAddressMap(locked).find(BB);
720 if (I != getBasicBlockAddressMap(locked).end()) {
721 return I->second;
722 } else {
723 assert(0 && "JIT does not have BB address for address-of-label, was"
724 " it eliminated by optimizer?");
725 return 0;
726 }
727 }
728
729 /// getOrEmitGlobalVariable - Return the address of the specified global
730 /// variable, possibly emitting it to memory if needed. This is used by the
731 /// Emitter.
getOrEmitGlobalVariable(const GlobalVariable * GV)732 void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
733 MutexGuard locked(lock);
734
735 void *Ptr = getPointerToGlobalIfAvailable(GV);
736 if (Ptr) return Ptr;
737
738 // If the global is external, just remember the address.
739 if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage()) {
740 #if HAVE___DSO_HANDLE
741 if (GV->getName() == "__dso_handle")
742 return (void*)&__dso_handle;
743 #endif
744 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName());
745 if (Ptr == 0) {
746 report_fatal_error("Could not resolve external global address: "
747 +GV->getName());
748 }
749 addGlobalMapping(GV, Ptr);
750 } else {
751 // If the global hasn't been emitted to memory yet, allocate space and
752 // emit it into memory.
753 Ptr = getMemoryForGV(GV);
754 addGlobalMapping(GV, Ptr);
755 EmitGlobalVariable(GV); // Initialize the variable.
756 }
757 return Ptr;
758 }
759
760 /// recompileAndRelinkFunction - This method is used to force a function
761 /// which has already been compiled, to be compiled again, possibly
762 /// after it has been modified. Then the entry to the old copy is overwritten
763 /// with a branch to the new copy. If there was no old copy, this acts
764 /// just like JIT::getPointerToFunction().
765 ///
recompileAndRelinkFunction(Function * F)766 void *JIT::recompileAndRelinkFunction(Function *F) {
767 void *OldAddr = getPointerToGlobalIfAvailable(F);
768
769 // If it's not already compiled there is no reason to patch it up.
770 if (OldAddr == 0) { return getPointerToFunction(F); }
771
772 // Delete the old function mapping.
773 addGlobalMapping(F, 0);
774
775 // Recodegen the function
776 runJITOnFunction(F);
777
778 // Update state, forward the old function to the new function.
779 void *Addr = getPointerToGlobalIfAvailable(F);
780 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
781 TJI.replaceMachineCodeForFunction(OldAddr, Addr);
782 return Addr;
783 }
784
785 /// getMemoryForGV - This method abstracts memory allocation of global
786 /// variable so that the JIT can allocate thread local variables depending
787 /// on the target.
788 ///
getMemoryForGV(const GlobalVariable * GV)789 char* JIT::getMemoryForGV(const GlobalVariable* GV) {
790 char *Ptr;
791
792 // GlobalVariable's which are not "constant" will cause trouble in a server
793 // situation. It's returned in the same block of memory as code which may
794 // not be writable.
795 if (isGVCompilationDisabled() && !GV->isConstant()) {
796 report_fatal_error("Compilation of non-internal GlobalValue is disabled!");
797 }
798
799 // Some applications require globals and code to live together, so they may
800 // be allocated into the same buffer, but in general globals are allocated
801 // through the memory manager which puts them near the code but not in the
802 // same buffer.
803 const Type *GlobalType = GV->getType()->getElementType();
804 size_t S = getTargetData()->getTypeAllocSize(GlobalType);
805 size_t A = getTargetData()->getPreferredAlignment(GV);
806 if (GV->isThreadLocal()) {
807 MutexGuard locked(lock);
808 Ptr = TJI.allocateThreadLocalMemory(S);
809 } else if (TJI.allocateSeparateGVMemory()) {
810 if (A <= 8) {
811 Ptr = (char*)malloc(S);
812 } else {
813 // Allocate S+A bytes of memory, then use an aligned pointer within that
814 // space.
815 Ptr = (char*)malloc(S+A);
816 unsigned MisAligned = ((intptr_t)Ptr & (A-1));
817 Ptr = Ptr + (MisAligned ? (A-MisAligned) : 0);
818 }
819 } else if (AllocateGVsWithCode) {
820 Ptr = (char*)JCE->allocateSpace(S, A);
821 } else {
822 Ptr = (char*)JCE->allocateGlobal(S, A);
823 }
824 return Ptr;
825 }
826
addPendingFunction(Function * F)827 void JIT::addPendingFunction(Function *F) {
828 MutexGuard locked(lock);
829 jitstate->getPendingFunctions(locked).push_back(F);
830 }
831
832
~JITEventListener()833 JITEventListener::~JITEventListener() {}
834