1 //===- DwarfEHPrepare - Prepare exception handling for code generation ----===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
12 //===----------------------------------------------------------------------===//
45 #define DEBUG_TYPE "dwarf-eh-prepare"
69   Value *GetExceptionObject(ResumeInst *RI);
93 Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {  in GetExceptionObject()  argument
94   Value *V = RI->getOperand(0);  in GetExceptionObject()
102     if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {  in GetExceptionObject()
103       ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));  in GetExceptionObject()
104       if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&  in GetExceptionObject()
105           ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {  in GetExceptionObject()
106         ExnObj = ExcIVI->getOperand(1);  in GetExceptionObject()
107         SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));  in GetExceptionObject()
114     ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj",  in GetExceptionObject()
115                                       RI->getIterator());  in GetExceptionObject()
117   RI->eraseFromParent();  in GetExceptionObject()
120     if (SelIVI->use_empty())  in GetExceptionObject()
121       SelIVI->eraseFromParent();  in GetExceptionObject()
122     if (ExcIVI->use_empty())  in GetExceptionObject()
123       ExcIVI->eraseFromParent();  in GetExceptionObject()
124     if (SelLoad && SelLoad->use_empty())  in GetExceptionObject()
125       SelLoad->eraseFromParent();  in GetExceptionObject()
138   for (auto *RI : Resumes) {  in pruneUnreachableResumes()  local
140       if (isPotentiallyReachable(LP, RI, nullptr, &DTU->getDomTree())) {  in pruneUnreachableResumes()
157     ResumeInst *RI = Resumes[I];  in pruneUnreachableResumes()  local
159       Resumes[ResumesLeft++] = RI;  in pruneUnreachableResumes()
161       BasicBlock *BB = RI->getParent();  in pruneUnreachableResumes()
162       new UnreachableInst(Ctx, RI->getIterator());  in pruneUnreachableResumes()
163       RI->eraseFromParent();  in pruneUnreachableResumes()
179     if (auto *RI = dyn_cast<ResumeInst>(BB.getTerminator()))  in InsertUnwindResumeCalls()  local
180       Resumes.push_back(RI);  in InsertUnwindResumeCalls()
182       if (LP->isCleanup())  in InsertUnwindResumeCalls()
191   // Check the personality, don't do anything if it's scope-based.  in InsertUnwindResumeCalls()
205         if (LP->isCleanup())  in InsertUnwindResumeCalls()
208     NumCleanupLandingPadsUnreachable += CleanupLPads.size() - NumRemainingLPs;  in InsertUnwindResumeCalls()
209     NumCleanupLandingPadsRemaining -= CleanupLPads.size() - NumRemainingLPs;  in InsertUnwindResumeCalls()
216   // RewindFunction - _Unwind_Resume or the target equivalent.  in InsertUnwindResumeCalls()
237   RewindFunction = F.getParent()->getOrInsertFunction(RewindName, FTy);  in InsertUnwindResumeCalls()
243     ResumeInst *RI = Resumes.front();  in InsertUnwindResumeCalls()  local
244     BasicBlock *UnwindBB = RI->getParent();  in InsertUnwindResumeCalls()
245     Value *ExnObj = GetExceptionObject(RI);  in InsertUnwindResumeCalls()
253     // The verifier requires that all calls of debug-info-bearing functions  in InsertUnwindResumeCalls()
254     // from debug-info-bearing functions have a debug location (for inlining  in InsertUnwindResumeCalls()
257     if (RewindFn && RewindFn->getSubprogram())  in InsertUnwindResumeCalls()
259         CI->setDebugLoc(DILocation::get(SP->getContext(), 0, 0, SP));  in InsertUnwindResumeCalls()
260     CI->setCallingConv(RewindFunctionCallingConv);  in InsertUnwindResumeCalls()
263     CI->setDoesNotReturn();  in InsertUnwindResumeCalls()
279   for (ResumeInst *RI : Resumes) {  in InsertUnwindResumeCalls()
280     BasicBlock *Parent = RI->getParent();  in InsertUnwindResumeCalls()
284     Value *ExnObj = GetExceptionObject(RI);  in InsertUnwindResumeCalls()
285     PN->addIncoming(ExnObj, Parent);  in InsertUnwindResumeCalls()
296   // The verifier requires that all calls of debug-info-bearing functions  in InsertUnwindResumeCalls()
297   // from debug-info-bearing functions have a debug location (for inlining  in InsertUnwindResumeCalls()
300   if (RewindFn && RewindFn->getSubprogram())  in InsertUnwindResumeCalls()
302       CI->setDebugLoc(DILocation::get(SP->getContext(), 0, 0, SP));  in InsertUnwindResumeCalls()
303   CI->setCallingConv(RewindFunctionCallingConv);  in InsertUnwindResumeCalls()
306   CI->setDoesNotReturn();  in InsertUnwindResumeCalls()
310     DTU->applyUpdates(Updates);  in InsertUnwindResumeCalls()
344   bool runOnFunction(Function &F) override {  in runOnFunction()
347     const TargetLowering &TLI = *TM.getSubtargetImpl(F)->getTargetLowering();  in runOnFunction()
351       DT = &DTWP->getDomTree();  in runOnFunction()
360   void getAnalysisUsage(AnalysisUsage &AU) const override {  in getAnalysisUsage()
370   StringRef getPassName() const override {  in getPassName()
379   const auto &TLI = *TM->getSubtargetImpl(F)->getTargetLowering();  in run()
382   auto OptLevel = TM->getOptLevel();  in run()
389       prepareDwarfEH(OptLevel, F, TLI, DT, TTI, TM->getTargetTriple());  in run()