xref: /freebsd/contrib/llvm-project/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 //===---- IndirectionUtils.cpp - Utilities for call indirection in Orc ----===//
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/Triple.h"
12 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
13 #include "llvm/ExecutionEngine/Orc/OrcABISupport.h"
14 #include "llvm/IR/IRBuilder.h"
15 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
16 #include "llvm/MC/MCInstrAnalysis.h"
17 #include "llvm/Support/Format.h"
18 #include "llvm/Transforms/Utils/Cloning.h"
19 #include <sstream>
20 
21 #define DEBUG_TYPE "orc"
22 
23 using namespace llvm;
24 using namespace llvm::orc;
25 
26 namespace {
27 
28 class CompileCallbackMaterializationUnit : public orc::MaterializationUnit {
29 public:
30   using CompileFunction = JITCompileCallbackManager::CompileFunction;
31 
32   CompileCallbackMaterializationUnit(SymbolStringPtr Name,
33                                      CompileFunction Compile)
34       : MaterializationUnit(Interface(
35             SymbolFlagsMap({{Name, JITSymbolFlags::Exported}}), nullptr)),
36         Name(std::move(Name)), Compile(std::move(Compile)) {}
37 
38   StringRef getName() const override { return "<Compile Callbacks>"; }
39 
40 private:
41   void materialize(std::unique_ptr<MaterializationResponsibility> R) override {
42     SymbolMap Result;
43     Result[Name] = JITEvaluatedSymbol(Compile(), JITSymbolFlags::Exported);
44     // No dependencies, so these calls cannot fail.
45     cantFail(R->notifyResolved(Result));
46     cantFail(R->notifyEmitted());
47   }
48 
49   void discard(const JITDylib &JD, const SymbolStringPtr &Name) override {
50     llvm_unreachable("Discard should never occur on a LMU?");
51   }
52 
53   SymbolStringPtr Name;
54   CompileFunction Compile;
55 };
56 
57 } // namespace
58 
59 namespace llvm {
60 namespace orc {
61 
62 TrampolinePool::~TrampolinePool() = default;
63 void IndirectStubsManager::anchor() {}
64 
65 Expected<JITTargetAddress>
66 JITCompileCallbackManager::getCompileCallback(CompileFunction Compile) {
67   if (auto TrampolineAddr = TP->getTrampoline()) {
68     auto CallbackName =
69         ES.intern(std::string("cc") + std::to_string(++NextCallbackId));
70 
71     std::lock_guard<std::mutex> Lock(CCMgrMutex);
72     AddrToSymbol[*TrampolineAddr] = CallbackName;
73     cantFail(
74         CallbacksJD.define(std::make_unique<CompileCallbackMaterializationUnit>(
75             std::move(CallbackName), std::move(Compile))));
76     return *TrampolineAddr;
77   } else
78     return TrampolineAddr.takeError();
79 }
80 
81 JITTargetAddress JITCompileCallbackManager::executeCompileCallback(
82     JITTargetAddress TrampolineAddr) {
83   SymbolStringPtr Name;
84 
85   {
86     std::unique_lock<std::mutex> Lock(CCMgrMutex);
87     auto I = AddrToSymbol.find(TrampolineAddr);
88 
89     // If this address is not associated with a compile callback then report an
90     // error to the execution session and return ErrorHandlerAddress to the
91     // callee.
92     if (I == AddrToSymbol.end()) {
93       Lock.unlock();
94       std::string ErrMsg;
95       {
96         raw_string_ostream ErrMsgStream(ErrMsg);
97         ErrMsgStream << "No compile callback for trampoline at "
98                      << format("0x%016" PRIx64, TrampolineAddr);
99       }
100       ES.reportError(
101           make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode()));
102       return ErrorHandlerAddress;
103     } else
104       Name = I->second;
105   }
106 
107   if (auto Sym =
108           ES.lookup(makeJITDylibSearchOrder(
109                         &CallbacksJD, JITDylibLookupFlags::MatchAllSymbols),
110                     Name))
111     return Sym->getAddress();
112   else {
113     llvm::dbgs() << "Didn't find callback.\n";
114     // If anything goes wrong materializing Sym then report it to the session
115     // and return the ErrorHandlerAddress;
116     ES.reportError(Sym.takeError());
117     return ErrorHandlerAddress;
118   }
119 }
120 
121 Expected<std::unique_ptr<JITCompileCallbackManager>>
122 createLocalCompileCallbackManager(const Triple &T, ExecutionSession &ES,
123                                   JITTargetAddress ErrorHandlerAddress) {
124   switch (T.getArch()) {
125   default:
126     return make_error<StringError>(
127         std::string("No callback manager available for ") + T.str(),
128         inconvertibleErrorCode());
129   case Triple::aarch64:
130   case Triple::aarch64_32: {
131     typedef orc::LocalJITCompileCallbackManager<orc::OrcAArch64> CCMgrT;
132     return CCMgrT::Create(ES, ErrorHandlerAddress);
133     }
134 
135     case Triple::x86: {
136       typedef orc::LocalJITCompileCallbackManager<orc::OrcI386> CCMgrT;
137       return CCMgrT::Create(ES, ErrorHandlerAddress);
138     }
139 
140     case Triple::loongarch64: {
141       typedef orc::LocalJITCompileCallbackManager<orc::OrcLoongArch64> CCMgrT;
142       return CCMgrT::Create(ES, ErrorHandlerAddress);
143     }
144 
145     case Triple::mips: {
146       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Be> CCMgrT;
147       return CCMgrT::Create(ES, ErrorHandlerAddress);
148     }
149     case Triple::mipsel: {
150       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Le> CCMgrT;
151       return CCMgrT::Create(ES, ErrorHandlerAddress);
152     }
153 
154     case Triple::mips64:
155     case Triple::mips64el: {
156       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips64> CCMgrT;
157       return CCMgrT::Create(ES, ErrorHandlerAddress);
158     }
159 
160     case Triple::riscv64: {
161       typedef orc::LocalJITCompileCallbackManager<orc::OrcRiscv64> CCMgrT;
162       return CCMgrT::Create(ES, ErrorHandlerAddress);
163     }
164 
165     case Triple::x86_64: {
166       if (T.getOS() == Triple::OSType::Win32) {
167         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_Win32> CCMgrT;
168         return CCMgrT::Create(ES, ErrorHandlerAddress);
169       } else {
170         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_SysV> CCMgrT;
171         return CCMgrT::Create(ES, ErrorHandlerAddress);
172       }
173     }
174 
175   }
176 }
177 
178 std::function<std::unique_ptr<IndirectStubsManager>()>
179 createLocalIndirectStubsManagerBuilder(const Triple &T) {
180   switch (T.getArch()) {
181     default:
182       return [](){
183         return std::make_unique<
184                        orc::LocalIndirectStubsManager<orc::OrcGenericABI>>();
185       };
186 
187     case Triple::aarch64:
188     case Triple::aarch64_32:
189       return [](){
190         return std::make_unique<
191                        orc::LocalIndirectStubsManager<orc::OrcAArch64>>();
192       };
193 
194     case Triple::x86:
195       return [](){
196         return std::make_unique<
197                        orc::LocalIndirectStubsManager<orc::OrcI386>>();
198       };
199 
200     case Triple::loongarch64:
201       return []() {
202         return std::make_unique<
203             orc::LocalIndirectStubsManager<orc::OrcLoongArch64>>();
204       };
205 
206     case Triple::mips:
207       return [](){
208           return std::make_unique<
209                       orc::LocalIndirectStubsManager<orc::OrcMips32Be>>();
210       };
211 
212     case Triple::mipsel:
213       return [](){
214           return std::make_unique<
215                       orc::LocalIndirectStubsManager<orc::OrcMips32Le>>();
216       };
217 
218     case Triple::mips64:
219     case Triple::mips64el:
220       return [](){
221           return std::make_unique<
222                       orc::LocalIndirectStubsManager<orc::OrcMips64>>();
223       };
224 
225     case Triple::riscv64:
226       return []() {
227         return std::make_unique<
228             orc::LocalIndirectStubsManager<orc::OrcRiscv64>>();
229       };
230 
231     case Triple::x86_64:
232       if (T.getOS() == Triple::OSType::Win32) {
233         return [](){
234           return std::make_unique<
235                      orc::LocalIndirectStubsManager<orc::OrcX86_64_Win32>>();
236         };
237       } else {
238         return [](){
239           return std::make_unique<
240                      orc::LocalIndirectStubsManager<orc::OrcX86_64_SysV>>();
241         };
242       }
243 
244   }
245 }
246 
247 Constant* createIRTypedAddress(FunctionType &FT, JITTargetAddress Addr) {
248   Constant *AddrIntVal =
249     ConstantInt::get(Type::getInt64Ty(FT.getContext()), Addr);
250   Constant *AddrPtrVal =
251     ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
252                           PointerType::get(&FT, 0));
253   return AddrPtrVal;
254 }
255 
256 GlobalVariable* createImplPointer(PointerType &PT, Module &M,
257                                   const Twine &Name, Constant *Initializer) {
258   auto IP = new GlobalVariable(M, &PT, false, GlobalValue::ExternalLinkage,
259                                Initializer, Name, nullptr,
260                                GlobalValue::NotThreadLocal, 0, true);
261   IP->setVisibility(GlobalValue::HiddenVisibility);
262   return IP;
263 }
264 
265 void makeStub(Function &F, Value &ImplPointer) {
266   assert(F.isDeclaration() && "Can't turn a definition into a stub.");
267   assert(F.getParent() && "Function isn't in a module.");
268   Module &M = *F.getParent();
269   BasicBlock *EntryBlock = BasicBlock::Create(M.getContext(), "entry", &F);
270   IRBuilder<> Builder(EntryBlock);
271   LoadInst *ImplAddr = Builder.CreateLoad(F.getType(), &ImplPointer);
272   std::vector<Value*> CallArgs;
273   for (auto &A : F.args())
274     CallArgs.push_back(&A);
275   CallInst *Call = Builder.CreateCall(F.getFunctionType(), ImplAddr, CallArgs);
276   Call->setTailCall();
277   Call->setAttributes(F.getAttributes());
278   if (F.getReturnType()->isVoidTy())
279     Builder.CreateRetVoid();
280   else
281     Builder.CreateRet(Call);
282 }
283 
284 std::vector<GlobalValue *> SymbolLinkagePromoter::operator()(Module &M) {
285   std::vector<GlobalValue *> PromotedGlobals;
286 
287   for (auto &GV : M.global_values()) {
288     bool Promoted = true;
289 
290     // Rename if necessary.
291     if (!GV.hasName())
292       GV.setName("__orc_anon." + Twine(NextId++));
293     else if (GV.getName().startswith("\01L"))
294       GV.setName("__" + GV.getName().substr(1) + "." + Twine(NextId++));
295     else if (GV.hasLocalLinkage())
296       GV.setName("__orc_lcl." + GV.getName() + "." + Twine(NextId++));
297     else
298       Promoted = false;
299 
300     if (GV.hasLocalLinkage()) {
301       GV.setLinkage(GlobalValue::ExternalLinkage);
302       GV.setVisibility(GlobalValue::HiddenVisibility);
303       Promoted = true;
304     }
305     GV.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
306 
307     if (Promoted)
308       PromotedGlobals.push_back(&GV);
309   }
310 
311   return PromotedGlobals;
312 }
313 
314 Function* cloneFunctionDecl(Module &Dst, const Function &F,
315                             ValueToValueMapTy *VMap) {
316   Function *NewF =
317     Function::Create(cast<FunctionType>(F.getValueType()),
318                      F.getLinkage(), F.getName(), &Dst);
319   NewF->copyAttributesFrom(&F);
320 
321   if (VMap) {
322     (*VMap)[&F] = NewF;
323     auto NewArgI = NewF->arg_begin();
324     for (auto ArgI = F.arg_begin(), ArgE = F.arg_end(); ArgI != ArgE;
325          ++ArgI, ++NewArgI)
326       (*VMap)[&*ArgI] = &*NewArgI;
327   }
328 
329   return NewF;
330 }
331 
332 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
333                       ValueMaterializer *Materializer,
334                       Function *NewF) {
335   assert(!OrigF.isDeclaration() && "Nothing to move");
336   if (!NewF)
337     NewF = cast<Function>(VMap[&OrigF]);
338   else
339     assert(VMap[&OrigF] == NewF && "Incorrect function mapping in VMap.");
340   assert(NewF && "Function mapping missing from VMap.");
341   assert(NewF->getParent() != OrigF.getParent() &&
342          "moveFunctionBody should only be used to move bodies between "
343          "modules.");
344 
345   SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
346   CloneFunctionInto(NewF, &OrigF, VMap,
347                     CloneFunctionChangeType::DifferentModule, Returns, "",
348                     nullptr, nullptr, Materializer);
349   OrigF.deleteBody();
350 }
351 
352 GlobalVariable* cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
353                                         ValueToValueMapTy *VMap) {
354   GlobalVariable *NewGV = new GlobalVariable(
355       Dst, GV.getValueType(), GV.isConstant(),
356       GV.getLinkage(), nullptr, GV.getName(), nullptr,
357       GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
358   NewGV->copyAttributesFrom(&GV);
359   if (VMap)
360     (*VMap)[&GV] = NewGV;
361   return NewGV;
362 }
363 
364 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
365                                    ValueToValueMapTy &VMap,
366                                    ValueMaterializer *Materializer,
367                                    GlobalVariable *NewGV) {
368   assert(OrigGV.hasInitializer() && "Nothing to move");
369   if (!NewGV)
370     NewGV = cast<GlobalVariable>(VMap[&OrigGV]);
371   else
372     assert(VMap[&OrigGV] == NewGV &&
373            "Incorrect global variable mapping in VMap.");
374   assert(NewGV->getParent() != OrigGV.getParent() &&
375          "moveGlobalVariableInitializer should only be used to move "
376          "initializers between modules");
377 
378   NewGV->setInitializer(MapValue(OrigGV.getInitializer(), VMap, RF_None,
379                                  nullptr, Materializer));
380 }
381 
382 GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
383                                   ValueToValueMapTy &VMap) {
384   assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
385   auto *NewA = GlobalAlias::create(OrigA.getValueType(),
386                                    OrigA.getType()->getPointerAddressSpace(),
387                                    OrigA.getLinkage(), OrigA.getName(), &Dst);
388   NewA->copyAttributesFrom(&OrigA);
389   VMap[&OrigA] = NewA;
390   return NewA;
391 }
392 
393 void cloneModuleFlagsMetadata(Module &Dst, const Module &Src,
394                               ValueToValueMapTy &VMap) {
395   auto *MFs = Src.getModuleFlagsMetadata();
396   if (!MFs)
397     return;
398   for (auto *MF : MFs->operands())
399     Dst.addModuleFlag(MapMetadata(MF, VMap));
400 }
401 
402 Error addFunctionPointerRelocationsToCurrentSymbol(jitlink::Symbol &Sym,
403                                                    jitlink::LinkGraph &G,
404                                                    MCDisassembler &Disassembler,
405                                                    MCInstrAnalysis &MIA) {
406   // AArch64 appears to already come with the necessary relocations. Among other
407   // architectures, only x86_64 is currently implemented here.
408   if (G.getTargetTriple().getArch() != Triple::x86_64)
409     return Error::success();
410 
411   raw_null_ostream CommentStream;
412   auto &STI = Disassembler.getSubtargetInfo();
413 
414   // Determine the function bounds
415   auto &B = Sym.getBlock();
416   assert(!B.isZeroFill() && "expected content block");
417   auto SymAddress = Sym.getAddress();
418   auto SymStartInBlock =
419       (const uint8_t *)B.getContent().data() + Sym.getOffset();
420   auto SymSize = Sym.getSize() ? Sym.getSize() : B.getSize() - Sym.getOffset();
421   auto Content = ArrayRef(SymStartInBlock, SymSize);
422 
423   LLVM_DEBUG(dbgs() << "Adding self-relocations to " << Sym.getName() << "\n");
424 
425   SmallDenseSet<uintptr_t, 8> ExistingRelocations;
426   for (auto &E : B.edges()) {
427     if (E.isRelocation())
428       ExistingRelocations.insert(E.getOffset());
429   }
430 
431   size_t I = 0;
432   while (I < Content.size()) {
433     MCInst Instr;
434     uint64_t InstrSize = 0;
435     uint64_t InstrStart = SymAddress.getValue() + I;
436     auto DecodeStatus = Disassembler.getInstruction(
437         Instr, InstrSize, Content.drop_front(I), InstrStart, CommentStream);
438     if (DecodeStatus != MCDisassembler::Success) {
439       LLVM_DEBUG(dbgs() << "Aborting due to disassembly failure at address "
440                         << InstrStart);
441       return make_error<StringError>(
442           formatv("failed to disassemble at address {0:x16}", InstrStart),
443           inconvertibleErrorCode());
444     }
445     // Advance to the next instruction.
446     I += InstrSize;
447 
448     // Check for a PC-relative address equal to the symbol itself.
449     auto PCRelAddr =
450         MIA.evaluateMemoryOperandAddress(Instr, &STI, InstrStart, InstrSize);
451     if (!PCRelAddr || *PCRelAddr != SymAddress.getValue())
452       continue;
453 
454     auto RelocOffInInstr =
455         MIA.getMemoryOperandRelocationOffset(Instr, InstrSize);
456     if (!RelocOffInInstr || InstrSize - *RelocOffInInstr != 4) {
457       LLVM_DEBUG(dbgs() << "Skipping unknown self-relocation at "
458                         << InstrStart);
459       continue;
460     }
461 
462     auto RelocOffInBlock = orc::ExecutorAddr(InstrStart) + *RelocOffInInstr -
463                            SymAddress + Sym.getOffset();
464     if (ExistingRelocations.contains(RelocOffInBlock))
465       continue;
466 
467     LLVM_DEBUG(dbgs() << "Adding delta32 self-relocation at " << InstrStart);
468     B.addEdge(jitlink::x86_64::Delta32, RelocOffInBlock, Sym, /*Addend=*/-4);
469   }
470   return Error::success();
471 }
472 
473 } // End namespace orc.
474 } // End namespace llvm.
475