CGCleanup.cpp revision 225736
1//===--- CGCleanup.cpp - Bookkeeping and code emission for cleanups -------===// 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 file contains code dealing with the IR generation for cleanups 11// and related information. 12// 13// A "cleanup" is a piece of code which needs to be executed whenever 14// control transfers out of a particular scope. This can be 15// conditionalized to occur only on exceptional control flow, only on 16// normal control flow, or both. 17// 18//===----------------------------------------------------------------------===// 19 20#include "CodeGenFunction.h" 21#include "CGCleanup.h" 22 23using namespace clang; 24using namespace CodeGen; 25 26bool DominatingValue<RValue>::saved_type::needsSaving(RValue rv) { 27 if (rv.isScalar()) 28 return DominatingLLVMValue::needsSaving(rv.getScalarVal()); 29 if (rv.isAggregate()) 30 return DominatingLLVMValue::needsSaving(rv.getAggregateAddr()); 31 return true; 32} 33 34DominatingValue<RValue>::saved_type 35DominatingValue<RValue>::saved_type::save(CodeGenFunction &CGF, RValue rv) { 36 if (rv.isScalar()) { 37 llvm::Value *V = rv.getScalarVal(); 38 39 // These automatically dominate and don't need to be saved. 40 if (!DominatingLLVMValue::needsSaving(V)) 41 return saved_type(V, ScalarLiteral); 42 43 // Everything else needs an alloca. 44 llvm::Value *addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue"); 45 CGF.Builder.CreateStore(V, addr); 46 return saved_type(addr, ScalarAddress); 47 } 48 49 if (rv.isComplex()) { 50 CodeGenFunction::ComplexPairTy V = rv.getComplexVal(); 51 const llvm::Type *ComplexTy = 52 llvm::StructType::get(V.first->getType(), V.second->getType(), 53 (void*) 0); 54 llvm::Value *addr = CGF.CreateTempAlloca(ComplexTy, "saved-complex"); 55 CGF.StoreComplexToAddr(V, addr, /*volatile*/ false); 56 return saved_type(addr, ComplexAddress); 57 } 58 59 assert(rv.isAggregate()); 60 llvm::Value *V = rv.getAggregateAddr(); // TODO: volatile? 61 if (!DominatingLLVMValue::needsSaving(V)) 62 return saved_type(V, AggregateLiteral); 63 64 llvm::Value *addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue"); 65 CGF.Builder.CreateStore(V, addr); 66 return saved_type(addr, AggregateAddress); 67} 68 69/// Given a saved r-value produced by SaveRValue, perform the code 70/// necessary to restore it to usability at the current insertion 71/// point. 72RValue DominatingValue<RValue>::saved_type::restore(CodeGenFunction &CGF) { 73 switch (K) { 74 case ScalarLiteral: 75 return RValue::get(Value); 76 case ScalarAddress: 77 return RValue::get(CGF.Builder.CreateLoad(Value)); 78 case AggregateLiteral: 79 return RValue::getAggregate(Value); 80 case AggregateAddress: 81 return RValue::getAggregate(CGF.Builder.CreateLoad(Value)); 82 case ComplexAddress: 83 return RValue::getComplex(CGF.LoadComplexFromAddr(Value, false)); 84 } 85 86 llvm_unreachable("bad saved r-value kind"); 87 return RValue(); 88} 89 90/// Push an entry of the given size onto this protected-scope stack. 91char *EHScopeStack::allocate(size_t Size) { 92 if (!StartOfBuffer) { 93 unsigned Capacity = 1024; 94 while (Capacity < Size) Capacity *= 2; 95 StartOfBuffer = new char[Capacity]; 96 StartOfData = EndOfBuffer = StartOfBuffer + Capacity; 97 } else if (static_cast<size_t>(StartOfData - StartOfBuffer) < Size) { 98 unsigned CurrentCapacity = EndOfBuffer - StartOfBuffer; 99 unsigned UsedCapacity = CurrentCapacity - (StartOfData - StartOfBuffer); 100 101 unsigned NewCapacity = CurrentCapacity; 102 do { 103 NewCapacity *= 2; 104 } while (NewCapacity < UsedCapacity + Size); 105 106 char *NewStartOfBuffer = new char[NewCapacity]; 107 char *NewEndOfBuffer = NewStartOfBuffer + NewCapacity; 108 char *NewStartOfData = NewEndOfBuffer - UsedCapacity; 109 memcpy(NewStartOfData, StartOfData, UsedCapacity); 110 delete [] StartOfBuffer; 111 StartOfBuffer = NewStartOfBuffer; 112 EndOfBuffer = NewEndOfBuffer; 113 StartOfData = NewStartOfData; 114 } 115 116 assert(StartOfBuffer + Size <= StartOfData); 117 StartOfData -= Size; 118 return StartOfData; 119} 120 121EHScopeStack::stable_iterator 122EHScopeStack::getEnclosingEHCleanup(iterator it) const { 123 assert(it != end()); 124 do { 125 if (isa<EHCleanupScope>(*it)) { 126 if (cast<EHCleanupScope>(*it).isEHCleanup()) 127 return stabilize(it); 128 return cast<EHCleanupScope>(*it).getEnclosingEHCleanup(); 129 } 130 ++it; 131 } while (it != end()); 132 return stable_end(); 133} 134 135 136void *EHScopeStack::pushCleanup(CleanupKind Kind, size_t Size) { 137 assert(((Size % sizeof(void*)) == 0) && "cleanup type is misaligned"); 138 char *Buffer = allocate(EHCleanupScope::getSizeForCleanupSize(Size)); 139 bool IsNormalCleanup = Kind & NormalCleanup; 140 bool IsEHCleanup = Kind & EHCleanup; 141 bool IsActive = !(Kind & InactiveCleanup); 142 EHCleanupScope *Scope = 143 new (Buffer) EHCleanupScope(IsNormalCleanup, 144 IsEHCleanup, 145 IsActive, 146 Size, 147 BranchFixups.size(), 148 InnermostNormalCleanup, 149 InnermostEHCleanup); 150 if (IsNormalCleanup) 151 InnermostNormalCleanup = stable_begin(); 152 if (IsEHCleanup) 153 InnermostEHCleanup = stable_begin(); 154 155 return Scope->getCleanupBuffer(); 156} 157 158void EHScopeStack::popCleanup() { 159 assert(!empty() && "popping exception stack when not empty"); 160 161 assert(isa<EHCleanupScope>(*begin())); 162 EHCleanupScope &Cleanup = cast<EHCleanupScope>(*begin()); 163 InnermostNormalCleanup = Cleanup.getEnclosingNormalCleanup(); 164 InnermostEHCleanup = Cleanup.getEnclosingEHCleanup(); 165 StartOfData += Cleanup.getAllocatedSize(); 166 167 if (empty()) NextEHDestIndex = FirstEHDestIndex; 168 169 // Destroy the cleanup. 170 Cleanup.~EHCleanupScope(); 171 172 // Check whether we can shrink the branch-fixups stack. 173 if (!BranchFixups.empty()) { 174 // If we no longer have any normal cleanups, all the fixups are 175 // complete. 176 if (!hasNormalCleanups()) 177 BranchFixups.clear(); 178 179 // Otherwise we can still trim out unnecessary nulls. 180 else 181 popNullFixups(); 182 } 183} 184 185EHFilterScope *EHScopeStack::pushFilter(unsigned NumFilters) { 186 char *Buffer = allocate(EHFilterScope::getSizeForNumFilters(NumFilters)); 187 CatchDepth++; 188 return new (Buffer) EHFilterScope(NumFilters); 189} 190 191void EHScopeStack::popFilter() { 192 assert(!empty() && "popping exception stack when not empty"); 193 194 EHFilterScope &Filter = cast<EHFilterScope>(*begin()); 195 StartOfData += EHFilterScope::getSizeForNumFilters(Filter.getNumFilters()); 196 197 if (empty()) NextEHDestIndex = FirstEHDestIndex; 198 199 assert(CatchDepth > 0 && "mismatched filter push/pop"); 200 CatchDepth--; 201} 202 203EHCatchScope *EHScopeStack::pushCatch(unsigned NumHandlers) { 204 char *Buffer = allocate(EHCatchScope::getSizeForNumHandlers(NumHandlers)); 205 CatchDepth++; 206 EHCatchScope *Scope = new (Buffer) EHCatchScope(NumHandlers); 207 for (unsigned I = 0; I != NumHandlers; ++I) 208 Scope->getHandlers()[I].Index = getNextEHDestIndex(); 209 return Scope; 210} 211 212void EHScopeStack::pushTerminate() { 213 char *Buffer = allocate(EHTerminateScope::getSize()); 214 CatchDepth++; 215 new (Buffer) EHTerminateScope(getNextEHDestIndex()); 216} 217 218/// Remove any 'null' fixups on the stack. However, we can't pop more 219/// fixups than the fixup depth on the innermost normal cleanup, or 220/// else fixups that we try to add to that cleanup will end up in the 221/// wrong place. We *could* try to shrink fixup depths, but that's 222/// actually a lot of work for little benefit. 223void EHScopeStack::popNullFixups() { 224 // We expect this to only be called when there's still an innermost 225 // normal cleanup; otherwise there really shouldn't be any fixups. 226 assert(hasNormalCleanups()); 227 228 EHScopeStack::iterator it = find(InnermostNormalCleanup); 229 unsigned MinSize = cast<EHCleanupScope>(*it).getFixupDepth(); 230 assert(BranchFixups.size() >= MinSize && "fixup stack out of order"); 231 232 while (BranchFixups.size() > MinSize && 233 BranchFixups.back().Destination == 0) 234 BranchFixups.pop_back(); 235} 236 237void CodeGenFunction::initFullExprCleanup() { 238 // Create a variable to decide whether the cleanup needs to be run. 239 llvm::AllocaInst *active 240 = CreateTempAlloca(Builder.getInt1Ty(), "cleanup.cond"); 241 242 // Initialize it to false at a site that's guaranteed to be run 243 // before each evaluation. 244 llvm::BasicBlock *block = OutermostConditional->getStartingBlock(); 245 new llvm::StoreInst(Builder.getFalse(), active, &block->back()); 246 247 // Initialize it to true at the current location. 248 Builder.CreateStore(Builder.getTrue(), active); 249 250 // Set that as the active flag in the cleanup. 251 EHCleanupScope &cleanup = cast<EHCleanupScope>(*EHStack.begin()); 252 assert(cleanup.getActiveFlag() == 0 && "cleanup already has active flag?"); 253 cleanup.setActiveFlag(active); 254 255 if (cleanup.isNormalCleanup()) cleanup.setTestFlagInNormalCleanup(); 256 if (cleanup.isEHCleanup()) cleanup.setTestFlagInEHCleanup(); 257} 258 259void EHScopeStack::Cleanup::anchor() {} 260 261/// All the branch fixups on the EH stack have propagated out past the 262/// outermost normal cleanup; resolve them all by adding cases to the 263/// given switch instruction. 264static void ResolveAllBranchFixups(CodeGenFunction &CGF, 265 llvm::SwitchInst *Switch, 266 llvm::BasicBlock *CleanupEntry) { 267 llvm::SmallPtrSet<llvm::BasicBlock*, 4> CasesAdded; 268 269 for (unsigned I = 0, E = CGF.EHStack.getNumBranchFixups(); I != E; ++I) { 270 // Skip this fixup if its destination isn't set. 271 BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I); 272 if (Fixup.Destination == 0) continue; 273 274 // If there isn't an OptimisticBranchBlock, then InitialBranch is 275 // still pointing directly to its destination; forward it to the 276 // appropriate cleanup entry. This is required in the specific 277 // case of 278 // { std::string s; goto lbl; } 279 // lbl: 280 // i.e. where there's an unresolved fixup inside a single cleanup 281 // entry which we're currently popping. 282 if (Fixup.OptimisticBranchBlock == 0) { 283 new llvm::StoreInst(CGF.Builder.getInt32(Fixup.DestinationIndex), 284 CGF.getNormalCleanupDestSlot(), 285 Fixup.InitialBranch); 286 Fixup.InitialBranch->setSuccessor(0, CleanupEntry); 287 } 288 289 // Don't add this case to the switch statement twice. 290 if (!CasesAdded.insert(Fixup.Destination)) continue; 291 292 Switch->addCase(CGF.Builder.getInt32(Fixup.DestinationIndex), 293 Fixup.Destination); 294 } 295 296 CGF.EHStack.clearFixups(); 297} 298 299/// Transitions the terminator of the given exit-block of a cleanup to 300/// be a cleanup switch. 301static llvm::SwitchInst *TransitionToCleanupSwitch(CodeGenFunction &CGF, 302 llvm::BasicBlock *Block) { 303 // If it's a branch, turn it into a switch whose default 304 // destination is its original target. 305 llvm::TerminatorInst *Term = Block->getTerminator(); 306 assert(Term && "can't transition block without terminator"); 307 308 if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) { 309 assert(Br->isUnconditional()); 310 llvm::LoadInst *Load = 311 new llvm::LoadInst(CGF.getNormalCleanupDestSlot(), "cleanup.dest", Term); 312 llvm::SwitchInst *Switch = 313 llvm::SwitchInst::Create(Load, Br->getSuccessor(0), 4, Block); 314 Br->eraseFromParent(); 315 return Switch; 316 } else { 317 return cast<llvm::SwitchInst>(Term); 318 } 319} 320 321void CodeGenFunction::ResolveBranchFixups(llvm::BasicBlock *Block) { 322 assert(Block && "resolving a null target block"); 323 if (!EHStack.getNumBranchFixups()) return; 324 325 assert(EHStack.hasNormalCleanups() && 326 "branch fixups exist with no normal cleanups on stack"); 327 328 llvm::SmallPtrSet<llvm::BasicBlock*, 4> ModifiedOptimisticBlocks; 329 bool ResolvedAny = false; 330 331 for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) { 332 // Skip this fixup if its destination doesn't match. 333 BranchFixup &Fixup = EHStack.getBranchFixup(I); 334 if (Fixup.Destination != Block) continue; 335 336 Fixup.Destination = 0; 337 ResolvedAny = true; 338 339 // If it doesn't have an optimistic branch block, LatestBranch is 340 // already pointing to the right place. 341 llvm::BasicBlock *BranchBB = Fixup.OptimisticBranchBlock; 342 if (!BranchBB) 343 continue; 344 345 // Don't process the same optimistic branch block twice. 346 if (!ModifiedOptimisticBlocks.insert(BranchBB)) 347 continue; 348 349 llvm::SwitchInst *Switch = TransitionToCleanupSwitch(*this, BranchBB); 350 351 // Add a case to the switch. 352 Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), Block); 353 } 354 355 if (ResolvedAny) 356 EHStack.popNullFixups(); 357} 358 359/// Pops cleanup blocks until the given savepoint is reached. 360void CodeGenFunction::PopCleanupBlocks(EHScopeStack::stable_iterator Old) { 361 assert(Old.isValid()); 362 363 while (EHStack.stable_begin() != Old) { 364 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); 365 366 // As long as Old strictly encloses the scope's enclosing normal 367 // cleanup, we're going to emit another normal cleanup which 368 // fallthrough can propagate through. 369 bool FallThroughIsBranchThrough = 370 Old.strictlyEncloses(Scope.getEnclosingNormalCleanup()); 371 372 PopCleanupBlock(FallThroughIsBranchThrough); 373 } 374} 375 376static llvm::BasicBlock *CreateNormalEntry(CodeGenFunction &CGF, 377 EHCleanupScope &Scope) { 378 assert(Scope.isNormalCleanup()); 379 llvm::BasicBlock *Entry = Scope.getNormalBlock(); 380 if (!Entry) { 381 Entry = CGF.createBasicBlock("cleanup"); 382 Scope.setNormalBlock(Entry); 383 } 384 return Entry; 385} 386 387static llvm::BasicBlock *CreateEHEntry(CodeGenFunction &CGF, 388 EHCleanupScope &Scope) { 389 assert(Scope.isEHCleanup()); 390 llvm::BasicBlock *Entry = Scope.getEHBlock(); 391 if (!Entry) { 392 Entry = CGF.createBasicBlock("eh.cleanup"); 393 Scope.setEHBlock(Entry); 394 } 395 return Entry; 396} 397 398/// Attempts to reduce a cleanup's entry block to a fallthrough. This 399/// is basically llvm::MergeBlockIntoPredecessor, except 400/// simplified/optimized for the tighter constraints on cleanup blocks. 401/// 402/// Returns the new block, whatever it is. 403static llvm::BasicBlock *SimplifyCleanupEntry(CodeGenFunction &CGF, 404 llvm::BasicBlock *Entry) { 405 llvm::BasicBlock *Pred = Entry->getSinglePredecessor(); 406 if (!Pred) return Entry; 407 408 llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator()); 409 if (!Br || Br->isConditional()) return Entry; 410 assert(Br->getSuccessor(0) == Entry); 411 412 // If we were previously inserting at the end of the cleanup entry 413 // block, we'll need to continue inserting at the end of the 414 // predecessor. 415 bool WasInsertBlock = CGF.Builder.GetInsertBlock() == Entry; 416 assert(!WasInsertBlock || CGF.Builder.GetInsertPoint() == Entry->end()); 417 418 // Kill the branch. 419 Br->eraseFromParent(); 420 421 // Replace all uses of the entry with the predecessor, in case there 422 // are phis in the cleanup. 423 Entry->replaceAllUsesWith(Pred); 424 425 // Merge the blocks. 426 Pred->getInstList().splice(Pred->end(), Entry->getInstList()); 427 428 // Kill the entry block. 429 Entry->eraseFromParent(); 430 431 if (WasInsertBlock) 432 CGF.Builder.SetInsertPoint(Pred); 433 434 return Pred; 435} 436 437static void EmitCleanup(CodeGenFunction &CGF, 438 EHScopeStack::Cleanup *Fn, 439 EHScopeStack::Cleanup::Flags flags, 440 llvm::Value *ActiveFlag) { 441 // EH cleanups always occur within a terminate scope. 442 if (flags.isForEHCleanup()) CGF.EHStack.pushTerminate(); 443 444 // If there's an active flag, load it and skip the cleanup if it's 445 // false. 446 llvm::BasicBlock *ContBB = 0; 447 if (ActiveFlag) { 448 ContBB = CGF.createBasicBlock("cleanup.done"); 449 llvm::BasicBlock *CleanupBB = CGF.createBasicBlock("cleanup.action"); 450 llvm::Value *IsActive 451 = CGF.Builder.CreateLoad(ActiveFlag, "cleanup.is_active"); 452 CGF.Builder.CreateCondBr(IsActive, CleanupBB, ContBB); 453 CGF.EmitBlock(CleanupBB); 454 } 455 456 // Ask the cleanup to emit itself. 457 Fn->Emit(CGF, flags); 458 assert(CGF.HaveInsertPoint() && "cleanup ended with no insertion point?"); 459 460 // Emit the continuation block if there was an active flag. 461 if (ActiveFlag) 462 CGF.EmitBlock(ContBB); 463 464 // Leave the terminate scope. 465 if (flags.isForEHCleanup()) CGF.EHStack.popTerminate(); 466} 467 468static void ForwardPrebranchedFallthrough(llvm::BasicBlock *Exit, 469 llvm::BasicBlock *From, 470 llvm::BasicBlock *To) { 471 // Exit is the exit block of a cleanup, so it always terminates in 472 // an unconditional branch or a switch. 473 llvm::TerminatorInst *Term = Exit->getTerminator(); 474 475 if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) { 476 assert(Br->isUnconditional() && Br->getSuccessor(0) == From); 477 Br->setSuccessor(0, To); 478 } else { 479 llvm::SwitchInst *Switch = cast<llvm::SwitchInst>(Term); 480 for (unsigned I = 0, E = Switch->getNumSuccessors(); I != E; ++I) 481 if (Switch->getSuccessor(I) == From) 482 Switch->setSuccessor(I, To); 483 } 484} 485 486/// Pops a cleanup block. If the block includes a normal cleanup, the 487/// current insertion point is threaded through the cleanup, as are 488/// any branch fixups on the cleanup. 489void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) { 490 assert(!EHStack.empty() && "cleanup stack is empty!"); 491 assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!"); 492 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); 493 assert(Scope.getFixupDepth() <= EHStack.getNumBranchFixups()); 494 495 // Remember activation information. 496 bool IsActive = Scope.isActive(); 497 llvm::Value *NormalActiveFlag = 498 Scope.shouldTestFlagInNormalCleanup() ? Scope.getActiveFlag() : 0; 499 llvm::Value *EHActiveFlag = 500 Scope.shouldTestFlagInEHCleanup() ? Scope.getActiveFlag() : 0; 501 502 // Check whether we need an EH cleanup. This is only true if we've 503 // generated a lazy EH cleanup block. 504 bool RequiresEHCleanup = Scope.hasEHBranches(); 505 506 // Check the three conditions which might require a normal cleanup: 507 508 // - whether there are branch fix-ups through this cleanup 509 unsigned FixupDepth = Scope.getFixupDepth(); 510 bool HasFixups = EHStack.getNumBranchFixups() != FixupDepth; 511 512 // - whether there are branch-throughs or branch-afters 513 bool HasExistingBranches = Scope.hasBranches(); 514 515 // - whether there's a fallthrough 516 llvm::BasicBlock *FallthroughSource = Builder.GetInsertBlock(); 517 bool HasFallthrough = (FallthroughSource != 0 && IsActive); 518 519 // Branch-through fall-throughs leave the insertion point set to the 520 // end of the last cleanup, which points to the current scope. The 521 // rest of IR gen doesn't need to worry about this; it only happens 522 // during the execution of PopCleanupBlocks(). 523 bool HasPrebranchedFallthrough = 524 (FallthroughSource && FallthroughSource->getTerminator()); 525 526 // If this is a normal cleanup, then having a prebranched 527 // fallthrough implies that the fallthrough source unconditionally 528 // jumps here. 529 assert(!Scope.isNormalCleanup() || !HasPrebranchedFallthrough || 530 (Scope.getNormalBlock() && 531 FallthroughSource->getTerminator()->getSuccessor(0) 532 == Scope.getNormalBlock())); 533 534 bool RequiresNormalCleanup = false; 535 if (Scope.isNormalCleanup() && 536 (HasFixups || HasExistingBranches || HasFallthrough)) { 537 RequiresNormalCleanup = true; 538 } 539 540 EHScopeStack::Cleanup::Flags cleanupFlags; 541 if (Scope.isNormalCleanup()) 542 cleanupFlags.setIsNormalCleanupKind(); 543 if (Scope.isEHCleanup()) 544 cleanupFlags.setIsEHCleanupKind(); 545 546 // Even if we don't need the normal cleanup, we might still have 547 // prebranched fallthrough to worry about. 548 if (Scope.isNormalCleanup() && !RequiresNormalCleanup && 549 HasPrebranchedFallthrough) { 550 assert(!IsActive); 551 552 llvm::BasicBlock *NormalEntry = Scope.getNormalBlock(); 553 554 // If we're branching through this cleanup, just forward the 555 // prebranched fallthrough to the next cleanup, leaving the insert 556 // point in the old block. 557 if (FallthroughIsBranchThrough) { 558 EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup()); 559 llvm::BasicBlock *EnclosingEntry = 560 CreateNormalEntry(*this, cast<EHCleanupScope>(S)); 561 562 ForwardPrebranchedFallthrough(FallthroughSource, 563 NormalEntry, EnclosingEntry); 564 assert(NormalEntry->use_empty() && 565 "uses of entry remain after forwarding?"); 566 delete NormalEntry; 567 568 // Otherwise, we're branching out; just emit the next block. 569 } else { 570 EmitBlock(NormalEntry); 571 SimplifyCleanupEntry(*this, NormalEntry); 572 } 573 } 574 575 // If we don't need the cleanup at all, we're done. 576 if (!RequiresNormalCleanup && !RequiresEHCleanup) { 577 EHStack.popCleanup(); // safe because there are no fixups 578 assert(EHStack.getNumBranchFixups() == 0 || 579 EHStack.hasNormalCleanups()); 580 return; 581 } 582 583 // Copy the cleanup emission data out. Note that SmallVector 584 // guarantees maximal alignment for its buffer regardless of its 585 // type parameter. 586 llvm::SmallVector<char, 8*sizeof(void*)> CleanupBuffer; 587 CleanupBuffer.reserve(Scope.getCleanupSize()); 588 memcpy(CleanupBuffer.data(), 589 Scope.getCleanupBuffer(), Scope.getCleanupSize()); 590 CleanupBuffer.set_size(Scope.getCleanupSize()); 591 EHScopeStack::Cleanup *Fn = 592 reinterpret_cast<EHScopeStack::Cleanup*>(CleanupBuffer.data()); 593 594 // We want to emit the EH cleanup after the normal cleanup, but go 595 // ahead and do the setup for the EH cleanup while the scope is still 596 // alive. 597 llvm::BasicBlock *EHEntry = 0; 598 llvm::SmallVector<llvm::Instruction*, 2> EHInstsToAppend; 599 if (RequiresEHCleanup) { 600 EHEntry = CreateEHEntry(*this, Scope); 601 602 // Figure out the branch-through dest if necessary. 603 llvm::BasicBlock *EHBranchThroughDest = 0; 604 if (Scope.hasEHBranchThroughs()) { 605 assert(Scope.getEnclosingEHCleanup() != EHStack.stable_end()); 606 EHScope &S = *EHStack.find(Scope.getEnclosingEHCleanup()); 607 EHBranchThroughDest = CreateEHEntry(*this, cast<EHCleanupScope>(S)); 608 } 609 610 // If we have exactly one branch-after and no branch-throughs, we 611 // can dispatch it without a switch. 612 if (!Scope.hasEHBranchThroughs() && 613 Scope.getNumEHBranchAfters() == 1) { 614 assert(!EHBranchThroughDest); 615 616 // TODO: remove the spurious eh.cleanup.dest stores if this edge 617 // never went through any switches. 618 llvm::BasicBlock *BranchAfterDest = Scope.getEHBranchAfterBlock(0); 619 EHInstsToAppend.push_back(llvm::BranchInst::Create(BranchAfterDest)); 620 621 // Otherwise, if we have any branch-afters, we need a switch. 622 } else if (Scope.getNumEHBranchAfters()) { 623 // The default of the switch belongs to the branch-throughs if 624 // they exist. 625 llvm::BasicBlock *Default = 626 (EHBranchThroughDest ? EHBranchThroughDest : getUnreachableBlock()); 627 628 const unsigned SwitchCapacity = Scope.getNumEHBranchAfters(); 629 630 llvm::LoadInst *Load = 631 new llvm::LoadInst(getEHCleanupDestSlot(), "cleanup.dest"); 632 llvm::SwitchInst *Switch = 633 llvm::SwitchInst::Create(Load, Default, SwitchCapacity); 634 635 EHInstsToAppend.push_back(Load); 636 EHInstsToAppend.push_back(Switch); 637 638 for (unsigned I = 0, E = Scope.getNumEHBranchAfters(); I != E; ++I) 639 Switch->addCase(Scope.getEHBranchAfterIndex(I), 640 Scope.getEHBranchAfterBlock(I)); 641 642 // Otherwise, we have only branch-throughs; jump to the next EH 643 // cleanup. 644 } else { 645 assert(EHBranchThroughDest); 646 EHInstsToAppend.push_back(llvm::BranchInst::Create(EHBranchThroughDest)); 647 } 648 } 649 650 if (!RequiresNormalCleanup) { 651 EHStack.popCleanup(); 652 } else { 653 // If we have a fallthrough and no other need for the cleanup, 654 // emit it directly. 655 if (HasFallthrough && !HasPrebranchedFallthrough && 656 !HasFixups && !HasExistingBranches) { 657 658 // Fixups can cause us to optimistically create a normal block, 659 // only to later have no real uses for it. Just delete it in 660 // this case. 661 // TODO: we can potentially simplify all the uses after this. 662 if (Scope.getNormalBlock()) { 663 Scope.getNormalBlock()->replaceAllUsesWith(getUnreachableBlock()); 664 delete Scope.getNormalBlock(); 665 } 666 667 EHStack.popCleanup(); 668 669 EmitCleanup(*this, Fn, cleanupFlags, NormalActiveFlag); 670 671 // Otherwise, the best approach is to thread everything through 672 // the cleanup block and then try to clean up after ourselves. 673 } else { 674 // Force the entry block to exist. 675 llvm::BasicBlock *NormalEntry = CreateNormalEntry(*this, Scope); 676 677 // I. Set up the fallthrough edge in. 678 679 // If there's a fallthrough, we need to store the cleanup 680 // destination index. For fall-throughs this is always zero. 681 if (HasFallthrough) { 682 if (!HasPrebranchedFallthrough) 683 Builder.CreateStore(Builder.getInt32(0), getNormalCleanupDestSlot()); 684 685 // Otherwise, clear the IP if we don't have fallthrough because 686 // the cleanup is inactive. We don't need to save it because 687 // it's still just FallthroughSource. 688 } else if (FallthroughSource) { 689 assert(!IsActive && "source without fallthrough for active cleanup"); 690 Builder.ClearInsertionPoint(); 691 } 692 693 // II. Emit the entry block. This implicitly branches to it if 694 // we have fallthrough. All the fixups and existing branches 695 // should already be branched to it. 696 EmitBlock(NormalEntry); 697 698 // III. Figure out where we're going and build the cleanup 699 // epilogue. 700 701 bool HasEnclosingCleanups = 702 (Scope.getEnclosingNormalCleanup() != EHStack.stable_end()); 703 704 // Compute the branch-through dest if we need it: 705 // - if there are branch-throughs threaded through the scope 706 // - if fall-through is a branch-through 707 // - if there are fixups that will be optimistically forwarded 708 // to the enclosing cleanup 709 llvm::BasicBlock *BranchThroughDest = 0; 710 if (Scope.hasBranchThroughs() || 711 (FallthroughSource && FallthroughIsBranchThrough) || 712 (HasFixups && HasEnclosingCleanups)) { 713 assert(HasEnclosingCleanups); 714 EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup()); 715 BranchThroughDest = CreateNormalEntry(*this, cast<EHCleanupScope>(S)); 716 } 717 718 llvm::BasicBlock *FallthroughDest = 0; 719 llvm::SmallVector<llvm::Instruction*, 2> InstsToAppend; 720 721 // If there's exactly one branch-after and no other threads, 722 // we can route it without a switch. 723 if (!Scope.hasBranchThroughs() && !HasFixups && !HasFallthrough && 724 Scope.getNumBranchAfters() == 1) { 725 assert(!BranchThroughDest || !IsActive); 726 727 // TODO: clean up the possibly dead stores to the cleanup dest slot. 728 llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0); 729 InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter)); 730 731 // Build a switch-out if we need it: 732 // - if there are branch-afters threaded through the scope 733 // - if fall-through is a branch-after 734 // - if there are fixups that have nowhere left to go and 735 // so must be immediately resolved 736 } else if (Scope.getNumBranchAfters() || 737 (HasFallthrough && !FallthroughIsBranchThrough) || 738 (HasFixups && !HasEnclosingCleanups)) { 739 740 llvm::BasicBlock *Default = 741 (BranchThroughDest ? BranchThroughDest : getUnreachableBlock()); 742 743 // TODO: base this on the number of branch-afters and fixups 744 const unsigned SwitchCapacity = 10; 745 746 llvm::LoadInst *Load = 747 new llvm::LoadInst(getNormalCleanupDestSlot(), "cleanup.dest"); 748 llvm::SwitchInst *Switch = 749 llvm::SwitchInst::Create(Load, Default, SwitchCapacity); 750 751 InstsToAppend.push_back(Load); 752 InstsToAppend.push_back(Switch); 753 754 // Branch-after fallthrough. 755 if (FallthroughSource && !FallthroughIsBranchThrough) { 756 FallthroughDest = createBasicBlock("cleanup.cont"); 757 if (HasFallthrough) 758 Switch->addCase(Builder.getInt32(0), FallthroughDest); 759 } 760 761 for (unsigned I = 0, E = Scope.getNumBranchAfters(); I != E; ++I) { 762 Switch->addCase(Scope.getBranchAfterIndex(I), 763 Scope.getBranchAfterBlock(I)); 764 } 765 766 // If there aren't any enclosing cleanups, we can resolve all 767 // the fixups now. 768 if (HasFixups && !HasEnclosingCleanups) 769 ResolveAllBranchFixups(*this, Switch, NormalEntry); 770 } else { 771 // We should always have a branch-through destination in this case. 772 assert(BranchThroughDest); 773 InstsToAppend.push_back(llvm::BranchInst::Create(BranchThroughDest)); 774 } 775 776 // IV. Pop the cleanup and emit it. 777 EHStack.popCleanup(); 778 assert(EHStack.hasNormalCleanups() == HasEnclosingCleanups); 779 780 EmitCleanup(*this, Fn, cleanupFlags, NormalActiveFlag); 781 782 // Append the prepared cleanup prologue from above. 783 llvm::BasicBlock *NormalExit = Builder.GetInsertBlock(); 784 for (unsigned I = 0, E = InstsToAppend.size(); I != E; ++I) 785 NormalExit->getInstList().push_back(InstsToAppend[I]); 786 787 // Optimistically hope that any fixups will continue falling through. 788 for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); 789 I < E; ++I) { 790 BranchFixup &Fixup = EHStack.getBranchFixup(I); 791 if (!Fixup.Destination) continue; 792 if (!Fixup.OptimisticBranchBlock) { 793 new llvm::StoreInst(Builder.getInt32(Fixup.DestinationIndex), 794 getNormalCleanupDestSlot(), 795 Fixup.InitialBranch); 796 Fixup.InitialBranch->setSuccessor(0, NormalEntry); 797 } 798 Fixup.OptimisticBranchBlock = NormalExit; 799 } 800 801 // V. Set up the fallthrough edge out. 802 803 // Case 1: a fallthrough source exists but shouldn't branch to 804 // the cleanup because the cleanup is inactive. 805 if (!HasFallthrough && FallthroughSource) { 806 assert(!IsActive); 807 808 // If we have a prebranched fallthrough, that needs to be 809 // forwarded to the right block. 810 if (HasPrebranchedFallthrough) { 811 llvm::BasicBlock *Next; 812 if (FallthroughIsBranchThrough) { 813 Next = BranchThroughDest; 814 assert(!FallthroughDest); 815 } else { 816 Next = FallthroughDest; 817 } 818 819 ForwardPrebranchedFallthrough(FallthroughSource, NormalEntry, Next); 820 } 821 Builder.SetInsertPoint(FallthroughSource); 822 823 // Case 2: a fallthrough source exists and should branch to the 824 // cleanup, but we're not supposed to branch through to the next 825 // cleanup. 826 } else if (HasFallthrough && FallthroughDest) { 827 assert(!FallthroughIsBranchThrough); 828 EmitBlock(FallthroughDest); 829 830 // Case 3: a fallthrough source exists and should branch to the 831 // cleanup and then through to the next. 832 } else if (HasFallthrough) { 833 // Everything is already set up for this. 834 835 // Case 4: no fallthrough source exists. 836 } else { 837 Builder.ClearInsertionPoint(); 838 } 839 840 // VI. Assorted cleaning. 841 842 // Check whether we can merge NormalEntry into a single predecessor. 843 // This might invalidate (non-IR) pointers to NormalEntry. 844 llvm::BasicBlock *NewNormalEntry = 845 SimplifyCleanupEntry(*this, NormalEntry); 846 847 // If it did invalidate those pointers, and NormalEntry was the same 848 // as NormalExit, go back and patch up the fixups. 849 if (NewNormalEntry != NormalEntry && NormalEntry == NormalExit) 850 for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); 851 I < E; ++I) 852 EHStack.getBranchFixup(I).OptimisticBranchBlock = NewNormalEntry; 853 } 854 } 855 856 assert(EHStack.hasNormalCleanups() || EHStack.getNumBranchFixups() == 0); 857 858 // Emit the EH cleanup if required. 859 if (RequiresEHCleanup) { 860 CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); 861 862 EmitBlock(EHEntry); 863 864 cleanupFlags.setIsForEHCleanup(); 865 EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag); 866 867 // Append the prepared cleanup prologue from above. 868 llvm::BasicBlock *EHExit = Builder.GetInsertBlock(); 869 for (unsigned I = 0, E = EHInstsToAppend.size(); I != E; ++I) 870 EHExit->getInstList().push_back(EHInstsToAppend[I]); 871 872 Builder.restoreIP(SavedIP); 873 874 SimplifyCleanupEntry(*this, EHEntry); 875 } 876} 877 878/// isObviouslyBranchWithoutCleanups - Return true if a branch to the 879/// specified destination obviously has no cleanups to run. 'false' is always 880/// a conservatively correct answer for this method. 881bool CodeGenFunction::isObviouslyBranchWithoutCleanups(JumpDest Dest) const { 882 assert(Dest.getScopeDepth().encloses(EHStack.stable_begin()) 883 && "stale jump destination"); 884 885 // Calculate the innermost active normal cleanup. 886 EHScopeStack::stable_iterator TopCleanup = 887 EHStack.getInnermostActiveNormalCleanup(); 888 889 // If we're not in an active normal cleanup scope, or if the 890 // destination scope is within the innermost active normal cleanup 891 // scope, we don't need to worry about fixups. 892 if (TopCleanup == EHStack.stable_end() || 893 TopCleanup.encloses(Dest.getScopeDepth())) // works for invalid 894 return true; 895 896 // Otherwise, we might need some cleanups. 897 return false; 898} 899 900 901/// Terminate the current block by emitting a branch which might leave 902/// the current cleanup-protected scope. The target scope may not yet 903/// be known, in which case this will require a fixup. 904/// 905/// As a side-effect, this method clears the insertion point. 906void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) { 907 assert(Dest.getScopeDepth().encloses(EHStack.stable_begin()) 908 && "stale jump destination"); 909 910 if (!HaveInsertPoint()) 911 return; 912 913 // Create the branch. 914 llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock()); 915 916 // Calculate the innermost active normal cleanup. 917 EHScopeStack::stable_iterator 918 TopCleanup = EHStack.getInnermostActiveNormalCleanup(); 919 920 // If we're not in an active normal cleanup scope, or if the 921 // destination scope is within the innermost active normal cleanup 922 // scope, we don't need to worry about fixups. 923 if (TopCleanup == EHStack.stable_end() || 924 TopCleanup.encloses(Dest.getScopeDepth())) { // works for invalid 925 Builder.ClearInsertionPoint(); 926 return; 927 } 928 929 // If we can't resolve the destination cleanup scope, just add this 930 // to the current cleanup scope as a branch fixup. 931 if (!Dest.getScopeDepth().isValid()) { 932 BranchFixup &Fixup = EHStack.addBranchFixup(); 933 Fixup.Destination = Dest.getBlock(); 934 Fixup.DestinationIndex = Dest.getDestIndex(); 935 Fixup.InitialBranch = BI; 936 Fixup.OptimisticBranchBlock = 0; 937 938 Builder.ClearInsertionPoint(); 939 return; 940 } 941 942 // Otherwise, thread through all the normal cleanups in scope. 943 944 // Store the index at the start. 945 llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex()); 946 new llvm::StoreInst(Index, getNormalCleanupDestSlot(), BI); 947 948 // Adjust BI to point to the first cleanup block. 949 { 950 EHCleanupScope &Scope = 951 cast<EHCleanupScope>(*EHStack.find(TopCleanup)); 952 BI->setSuccessor(0, CreateNormalEntry(*this, Scope)); 953 } 954 955 // Add this destination to all the scopes involved. 956 EHScopeStack::stable_iterator I = TopCleanup; 957 EHScopeStack::stable_iterator E = Dest.getScopeDepth(); 958 if (E.strictlyEncloses(I)) { 959 while (true) { 960 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I)); 961 assert(Scope.isNormalCleanup()); 962 I = Scope.getEnclosingNormalCleanup(); 963 964 // If this is the last cleanup we're propagating through, tell it 965 // that there's a resolved jump moving through it. 966 if (!E.strictlyEncloses(I)) { 967 Scope.addBranchAfter(Index, Dest.getBlock()); 968 break; 969 } 970 971 // Otherwise, tell the scope that there's a jump propoagating 972 // through it. If this isn't new information, all the rest of 973 // the work has been done before. 974 if (!Scope.addBranchThrough(Dest.getBlock())) 975 break; 976 } 977 } 978 979 Builder.ClearInsertionPoint(); 980} 981 982void CodeGenFunction::EmitBranchThroughEHCleanup(UnwindDest Dest) { 983 // We should never get invalid scope depths for an UnwindDest; that 984 // implies that the destination wasn't set up correctly. 985 assert(Dest.getScopeDepth().isValid() && "invalid scope depth on EH dest?"); 986 987 if (!HaveInsertPoint()) 988 return; 989 990 // Create the branch. 991 llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock()); 992 993 // Calculate the innermost active cleanup. 994 EHScopeStack::stable_iterator 995 InnermostCleanup = EHStack.getInnermostActiveEHCleanup(); 996 997 // If the destination is in the same EH cleanup scope as us, we 998 // don't need to thread through anything. 999 if (InnermostCleanup.encloses(Dest.getScopeDepth())) { 1000 Builder.ClearInsertionPoint(); 1001 return; 1002 } 1003 assert(InnermostCleanup != EHStack.stable_end()); 1004 1005 // Store the index at the start. 1006 llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex()); 1007 new llvm::StoreInst(Index, getEHCleanupDestSlot(), BI); 1008 1009 // Adjust BI to point to the first cleanup block. 1010 { 1011 EHCleanupScope &Scope = 1012 cast<EHCleanupScope>(*EHStack.find(InnermostCleanup)); 1013 BI->setSuccessor(0, CreateEHEntry(*this, Scope)); 1014 } 1015 1016 // Add this destination to all the scopes involved. 1017 for (EHScopeStack::stable_iterator 1018 I = InnermostCleanup, E = Dest.getScopeDepth(); ; ) { 1019 assert(E.strictlyEncloses(I)); 1020 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I)); 1021 assert(Scope.isEHCleanup()); 1022 I = Scope.getEnclosingEHCleanup(); 1023 1024 // If this is the last cleanup we're propagating through, add this 1025 // as a branch-after. 1026 if (I == E) { 1027 Scope.addEHBranchAfter(Index, Dest.getBlock()); 1028 break; 1029 } 1030 1031 // Otherwise, add it as a branch-through. If this isn't new 1032 // information, all the rest of the work has been done before. 1033 if (!Scope.addEHBranchThrough(Dest.getBlock())) 1034 break; 1035 } 1036 1037 Builder.ClearInsertionPoint(); 1038} 1039 1040static bool IsUsedAsNormalCleanup(EHScopeStack &EHStack, 1041 EHScopeStack::stable_iterator C) { 1042 // If we needed a normal block for any reason, that counts. 1043 if (cast<EHCleanupScope>(*EHStack.find(C)).getNormalBlock()) 1044 return true; 1045 1046 // Check whether any enclosed cleanups were needed. 1047 for (EHScopeStack::stable_iterator 1048 I = EHStack.getInnermostNormalCleanup(); 1049 I != C; ) { 1050 assert(C.strictlyEncloses(I)); 1051 EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I)); 1052 if (S.getNormalBlock()) return true; 1053 I = S.getEnclosingNormalCleanup(); 1054 } 1055 1056 return false; 1057} 1058 1059static bool IsUsedAsEHCleanup(EHScopeStack &EHStack, 1060 EHScopeStack::stable_iterator C) { 1061 // If we needed an EH block for any reason, that counts. 1062 if (cast<EHCleanupScope>(*EHStack.find(C)).getEHBlock()) 1063 return true; 1064 1065 // Check whether any enclosed cleanups were needed. 1066 for (EHScopeStack::stable_iterator 1067 I = EHStack.getInnermostEHCleanup(); I != C; ) { 1068 assert(C.strictlyEncloses(I)); 1069 EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I)); 1070 if (S.getEHBlock()) return true; 1071 I = S.getEnclosingEHCleanup(); 1072 } 1073 1074 return false; 1075} 1076 1077enum ForActivation_t { 1078 ForActivation, 1079 ForDeactivation 1080}; 1081 1082/// The given cleanup block is changing activation state. Configure a 1083/// cleanup variable if necessary. 1084/// 1085/// It would be good if we had some way of determining if there were 1086/// extra uses *after* the change-over point. 1087static void SetupCleanupBlockActivation(CodeGenFunction &CGF, 1088 EHScopeStack::stable_iterator C, 1089 ForActivation_t Kind) { 1090 EHCleanupScope &Scope = cast<EHCleanupScope>(*CGF.EHStack.find(C)); 1091 1092 // We always need the flag if we're activating the cleanup, because 1093 // we have to assume that the current location doesn't necessarily 1094 // dominate all future uses of the cleanup. 1095 bool NeedFlag = (Kind == ForActivation); 1096 1097 // Calculate whether the cleanup was used: 1098 1099 // - as a normal cleanup 1100 if (Scope.isNormalCleanup() && IsUsedAsNormalCleanup(CGF.EHStack, C)) { 1101 Scope.setTestFlagInNormalCleanup(); 1102 NeedFlag = true; 1103 } 1104 1105 // - as an EH cleanup 1106 if (Scope.isEHCleanup() && IsUsedAsEHCleanup(CGF.EHStack, C)) { 1107 Scope.setTestFlagInEHCleanup(); 1108 NeedFlag = true; 1109 } 1110 1111 // If it hasn't yet been used as either, we're done. 1112 if (!NeedFlag) return; 1113 1114 llvm::AllocaInst *Var = Scope.getActiveFlag(); 1115 if (!Var) { 1116 Var = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), "cleanup.isactive"); 1117 Scope.setActiveFlag(Var); 1118 1119 // Initialize to true or false depending on whether it was 1120 // active up to this point. 1121 CGF.InitTempAlloca(Var, CGF.Builder.getInt1(Kind == ForDeactivation)); 1122 } 1123 1124 CGF.Builder.CreateStore(CGF.Builder.getInt1(Kind == ForActivation), Var); 1125} 1126 1127/// Activate a cleanup that was created in an inactivated state. 1128void CodeGenFunction::ActivateCleanupBlock(EHScopeStack::stable_iterator C) { 1129 assert(C != EHStack.stable_end() && "activating bottom of stack?"); 1130 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C)); 1131 assert(!Scope.isActive() && "double activation"); 1132 1133 SetupCleanupBlockActivation(*this, C, ForActivation); 1134 1135 Scope.setActive(true); 1136} 1137 1138/// Deactive a cleanup that was created in an active state. 1139void CodeGenFunction::DeactivateCleanupBlock(EHScopeStack::stable_iterator C) { 1140 assert(C != EHStack.stable_end() && "deactivating bottom of stack?"); 1141 EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C)); 1142 assert(Scope.isActive() && "double deactivation"); 1143 1144 // If it's the top of the stack, just pop it. 1145 if (C == EHStack.stable_begin()) { 1146 // If it's a normal cleanup, we need to pretend that the 1147 // fallthrough is unreachable. 1148 CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); 1149 PopCleanupBlock(); 1150 Builder.restoreIP(SavedIP); 1151 return; 1152 } 1153 1154 // Otherwise, follow the general case. 1155 SetupCleanupBlockActivation(*this, C, ForDeactivation); 1156 1157 Scope.setActive(false); 1158} 1159 1160llvm::Value *CodeGenFunction::getNormalCleanupDestSlot() { 1161 if (!NormalCleanupDest) 1162 NormalCleanupDest = 1163 CreateTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot"); 1164 return NormalCleanupDest; 1165} 1166 1167llvm::Value *CodeGenFunction::getEHCleanupDestSlot() { 1168 if (!EHCleanupDest) 1169 EHCleanupDest = 1170 CreateTempAlloca(Builder.getInt32Ty(), "eh.cleanup.dest.slot"); 1171 return EHCleanupDest; 1172} 1173