CGBlocks.cpp revision 276479
1//===--- CGBlocks.cpp - Emit LLVM Code for declarations -------------------===// 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 contains code to emit blocks. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CGBlocks.h" 15#include "CGDebugInfo.h" 16#include "CGObjCRuntime.h" 17#include "CodeGenFunction.h" 18#include "CodeGenModule.h" 19#include "clang/AST/DeclObjC.h" 20#include "llvm/ADT/SmallSet.h" 21#include "llvm/IR/CallSite.h" 22#include "llvm/IR/DataLayout.h" 23#include "llvm/IR/Module.h" 24#include <algorithm> 25#include <cstdio> 26 27using namespace clang; 28using namespace CodeGen; 29 30CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name) 31 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false), 32 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false), 33 StructureType(nullptr), Block(block), 34 DominatingIP(nullptr) { 35 36 // Skip asm prefix, if any. 'name' is usually taken directly from 37 // the mangled name of the enclosing function. 38 if (!name.empty() && name[0] == '\01') 39 name = name.substr(1); 40} 41 42// Anchor the vtable to this translation unit. 43CodeGenModule::ByrefHelpers::~ByrefHelpers() {} 44 45/// Build the given block as a global block. 46static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, 47 const CGBlockInfo &blockInfo, 48 llvm::Constant *blockFn); 49 50/// Build the helper function to copy a block. 51static llvm::Constant *buildCopyHelper(CodeGenModule &CGM, 52 const CGBlockInfo &blockInfo) { 53 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo); 54} 55 56/// Build the helper function to dispose of a block. 57static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM, 58 const CGBlockInfo &blockInfo) { 59 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo); 60} 61 62/// buildBlockDescriptor - Build the block descriptor meta-data for a block. 63/// buildBlockDescriptor is accessed from 5th field of the Block_literal 64/// meta-data and contains stationary information about the block literal. 65/// Its definition will have 4 (or optinally 6) words. 66/// \code 67/// struct Block_descriptor { 68/// unsigned long reserved; 69/// unsigned long size; // size of Block_literal metadata in bytes. 70/// void *copy_func_helper_decl; // optional copy helper. 71/// void *destroy_func_decl; // optioanl destructor helper. 72/// void *block_method_encoding_address; // @encode for block literal signature. 73/// void *block_layout_info; // encoding of captured block variables. 74/// }; 75/// \endcode 76static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM, 77 const CGBlockInfo &blockInfo) { 78 ASTContext &C = CGM.getContext(); 79 80 llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy); 81 llvm::Type *i8p = NULL; 82 if (CGM.getLangOpts().OpenCL) 83 i8p = 84 llvm::Type::getInt8PtrTy( 85 CGM.getLLVMContext(), C.getTargetAddressSpace(LangAS::opencl_constant)); 86 else 87 i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 88 89 SmallVector<llvm::Constant*, 6> elements; 90 91 // reserved 92 elements.push_back(llvm::ConstantInt::get(ulong, 0)); 93 94 // Size 95 // FIXME: What is the right way to say this doesn't fit? We should give 96 // a user diagnostic in that case. Better fix would be to change the 97 // API to size_t. 98 elements.push_back(llvm::ConstantInt::get(ulong, 99 blockInfo.BlockSize.getQuantity())); 100 101 // Optional copy/dispose helpers. 102 if (blockInfo.NeedsCopyDispose) { 103 // copy_func_helper_decl 104 elements.push_back(buildCopyHelper(CGM, blockInfo)); 105 106 // destroy_func_decl 107 elements.push_back(buildDisposeHelper(CGM, blockInfo)); 108 } 109 110 // Signature. Mandatory ObjC-style method descriptor @encode sequence. 111 std::string typeAtEncoding = 112 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr()); 113 elements.push_back(llvm::ConstantExpr::getBitCast( 114 CGM.GetAddrOfConstantCString(typeAtEncoding), i8p)); 115 116 // GC layout. 117 if (C.getLangOpts().ObjC1) { 118 if (CGM.getLangOpts().getGC() != LangOptions::NonGC) 119 elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo)); 120 else 121 elements.push_back(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo)); 122 } 123 else 124 elements.push_back(llvm::Constant::getNullValue(i8p)); 125 126 llvm::Constant *init = llvm::ConstantStruct::getAnon(elements); 127 128 llvm::GlobalVariable *global = 129 new llvm::GlobalVariable(CGM.getModule(), init->getType(), true, 130 llvm::GlobalValue::InternalLinkage, 131 init, "__block_descriptor_tmp"); 132 133 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType()); 134} 135 136/* 137 Purely notional variadic template describing the layout of a block. 138 139 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes> 140 struct Block_literal { 141 /// Initialized to one of: 142 /// extern void *_NSConcreteStackBlock[]; 143 /// extern void *_NSConcreteGlobalBlock[]; 144 /// 145 /// In theory, we could start one off malloc'ed by setting 146 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using 147 /// this isa: 148 /// extern void *_NSConcreteMallocBlock[]; 149 struct objc_class *isa; 150 151 /// These are the flags (with corresponding bit number) that the 152 /// compiler is actually supposed to know about. 153 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block 154 /// descriptor provides copy and dispose helper functions 155 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured 156 /// object with a nontrivial destructor or copy constructor 157 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated 158 /// as global memory 159 /// 29. BLOCK_USE_STRET - indicates that the block function 160 /// uses stret, which objc_msgSend needs to know about 161 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an 162 /// @encoded signature string 163 /// And we're not supposed to manipulate these: 164 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved 165 /// to malloc'ed memory 166 /// 27. BLOCK_IS_GC - indicates that the block has been moved to 167 /// to GC-allocated memory 168 /// Additionally, the bottom 16 bits are a reference count which 169 /// should be zero on the stack. 170 int flags; 171 172 /// Reserved; should be zero-initialized. 173 int reserved; 174 175 /// Function pointer generated from block literal. 176 _ResultType (*invoke)(Block_literal *, _ParamTypes...); 177 178 /// Block description metadata generated from block literal. 179 struct Block_descriptor *block_descriptor; 180 181 /// Captured values follow. 182 _CapturesTypes captures...; 183 }; 184 */ 185 186/// The number of fields in a block header. 187const unsigned BlockHeaderSize = 5; 188 189namespace { 190 /// A chunk of data that we actually have to capture in the block. 191 struct BlockLayoutChunk { 192 CharUnits Alignment; 193 CharUnits Size; 194 Qualifiers::ObjCLifetime Lifetime; 195 const BlockDecl::Capture *Capture; // null for 'this' 196 llvm::Type *Type; 197 198 BlockLayoutChunk(CharUnits align, CharUnits size, 199 Qualifiers::ObjCLifetime lifetime, 200 const BlockDecl::Capture *capture, 201 llvm::Type *type) 202 : Alignment(align), Size(size), Lifetime(lifetime), 203 Capture(capture), Type(type) {} 204 205 /// Tell the block info that this chunk has the given field index. 206 void setIndex(CGBlockInfo &info, unsigned index) { 207 if (!Capture) 208 info.CXXThisIndex = index; 209 else 210 info.Captures[Capture->getVariable()] 211 = CGBlockInfo::Capture::makeIndex(index); 212 } 213 }; 214 215 /// Order by 1) all __strong together 2) next, all byfref together 3) next, 216 /// all __weak together. Preserve descending alignment in all situations. 217 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) { 218 CharUnits LeftValue, RightValue; 219 bool LeftByref = left.Capture ? left.Capture->isByRef() : false; 220 bool RightByref = right.Capture ? right.Capture->isByRef() : false; 221 222 if (left.Lifetime == Qualifiers::OCL_Strong && 223 left.Alignment >= right.Alignment) 224 LeftValue = CharUnits::fromQuantity(64); 225 else if (LeftByref && left.Alignment >= right.Alignment) 226 LeftValue = CharUnits::fromQuantity(32); 227 else if (left.Lifetime == Qualifiers::OCL_Weak && 228 left.Alignment >= right.Alignment) 229 LeftValue = CharUnits::fromQuantity(16); 230 else 231 LeftValue = left.Alignment; 232 if (right.Lifetime == Qualifiers::OCL_Strong && 233 right.Alignment >= left.Alignment) 234 RightValue = CharUnits::fromQuantity(64); 235 else if (RightByref && right.Alignment >= left.Alignment) 236 RightValue = CharUnits::fromQuantity(32); 237 else if (right.Lifetime == Qualifiers::OCL_Weak && 238 right.Alignment >= left.Alignment) 239 RightValue = CharUnits::fromQuantity(16); 240 else 241 RightValue = right.Alignment; 242 243 return LeftValue > RightValue; 244 } 245} 246 247/// Determines if the given type is safe for constant capture in C++. 248static bool isSafeForCXXConstantCapture(QualType type) { 249 const RecordType *recordType = 250 type->getBaseElementTypeUnsafe()->getAs<RecordType>(); 251 252 // Only records can be unsafe. 253 if (!recordType) return true; 254 255 const auto *record = cast<CXXRecordDecl>(recordType->getDecl()); 256 257 // Maintain semantics for classes with non-trivial dtors or copy ctors. 258 if (!record->hasTrivialDestructor()) return false; 259 if (record->hasNonTrivialCopyConstructor()) return false; 260 261 // Otherwise, we just have to make sure there aren't any mutable 262 // fields that might have changed since initialization. 263 return !record->hasMutableFields(); 264} 265 266/// It is illegal to modify a const object after initialization. 267/// Therefore, if a const object has a constant initializer, we don't 268/// actually need to keep storage for it in the block; we'll just 269/// rematerialize it at the start of the block function. This is 270/// acceptable because we make no promises about address stability of 271/// captured variables. 272static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM, 273 CodeGenFunction *CGF, 274 const VarDecl *var) { 275 QualType type = var->getType(); 276 277 // We can only do this if the variable is const. 278 if (!type.isConstQualified()) return nullptr; 279 280 // Furthermore, in C++ we have to worry about mutable fields: 281 // C++ [dcl.type.cv]p4: 282 // Except that any class member declared mutable can be 283 // modified, any attempt to modify a const object during its 284 // lifetime results in undefined behavior. 285 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type)) 286 return nullptr; 287 288 // If the variable doesn't have any initializer (shouldn't this be 289 // invalid?), it's not clear what we should do. Maybe capture as 290 // zero? 291 const Expr *init = var->getInit(); 292 if (!init) return nullptr; 293 294 return CGM.EmitConstantInit(*var, CGF); 295} 296 297/// Get the low bit of a nonzero character count. This is the 298/// alignment of the nth byte if the 0th byte is universally aligned. 299static CharUnits getLowBit(CharUnits v) { 300 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1)); 301} 302 303static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, 304 SmallVectorImpl<llvm::Type*> &elementTypes) { 305 ASTContext &C = CGM.getContext(); 306 307 // The header is basically a 'struct { void *; int; int; void *; void *; }'. 308 CharUnits ptrSize, ptrAlign, intSize, intAlign; 309 std::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.VoidPtrTy); 310 std::tie(intSize, intAlign) = C.getTypeInfoInChars(C.IntTy); 311 312 // Are there crazy embedded platforms where this isn't true? 313 assert(intSize <= ptrSize && "layout assumptions horribly violated"); 314 315 CharUnits headerSize = ptrSize; 316 if (2 * intSize < ptrAlign) headerSize += ptrSize; 317 else headerSize += 2 * intSize; 318 headerSize += 2 * ptrSize; 319 320 info.BlockAlign = ptrAlign; 321 info.BlockSize = headerSize; 322 323 assert(elementTypes.empty()); 324 llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 325 llvm::Type *intTy = CGM.getTypes().ConvertType(C.IntTy); 326 elementTypes.push_back(i8p); 327 elementTypes.push_back(intTy); 328 elementTypes.push_back(intTy); 329 elementTypes.push_back(i8p); 330 elementTypes.push_back(CGM.getBlockDescriptorType()); 331 332 assert(elementTypes.size() == BlockHeaderSize); 333} 334 335/// Compute the layout of the given block. Attempts to lay the block 336/// out with minimal space requirements. 337static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, 338 CGBlockInfo &info) { 339 ASTContext &C = CGM.getContext(); 340 const BlockDecl *block = info.getBlockDecl(); 341 342 SmallVector<llvm::Type*, 8> elementTypes; 343 initializeForBlockHeader(CGM, info, elementTypes); 344 345 if (!block->hasCaptures()) { 346 info.StructureType = 347 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 348 info.CanBeGlobal = true; 349 return; 350 } 351 else if (C.getLangOpts().ObjC1 && 352 CGM.getLangOpts().getGC() == LangOptions::NonGC) 353 info.HasCapturedVariableLayout = true; 354 355 // Collect the layout chunks. 356 SmallVector<BlockLayoutChunk, 16> layout; 357 layout.reserve(block->capturesCXXThis() + 358 (block->capture_end() - block->capture_begin())); 359 360 CharUnits maxFieldAlign; 361 362 // First, 'this'. 363 if (block->capturesCXXThis()) { 364 assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && 365 "Can't capture 'this' outside a method"); 366 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C); 367 368 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType); 369 std::pair<CharUnits,CharUnits> tinfo 370 = CGM.getContext().getTypeInfoInChars(thisType); 371 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 372 373 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 374 Qualifiers::OCL_None, 375 nullptr, llvmType)); 376 } 377 378 // Next, all the block captures. 379 for (const auto &CI : block->captures()) { 380 const VarDecl *variable = CI.getVariable(); 381 382 if (CI.isByRef()) { 383 // We have to copy/dispose of the __block reference. 384 info.NeedsCopyDispose = true; 385 386 // Just use void* instead of a pointer to the byref type. 387 QualType byRefPtrTy = C.VoidPtrTy; 388 389 llvm::Type *llvmType = CGM.getTypes().ConvertType(byRefPtrTy); 390 std::pair<CharUnits,CharUnits> tinfo 391 = CGM.getContext().getTypeInfoInChars(byRefPtrTy); 392 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 393 394 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 395 Qualifiers::OCL_None, &CI, llvmType)); 396 continue; 397 } 398 399 // Otherwise, build a layout chunk with the size and alignment of 400 // the declaration. 401 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) { 402 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant); 403 continue; 404 } 405 406 // If we have a lifetime qualifier, honor it for capture purposes. 407 // That includes *not* copying it if it's __unsafe_unretained. 408 Qualifiers::ObjCLifetime lifetime = 409 variable->getType().getObjCLifetime(); 410 if (lifetime) { 411 switch (lifetime) { 412 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 413 case Qualifiers::OCL_ExplicitNone: 414 case Qualifiers::OCL_Autoreleasing: 415 break; 416 417 case Qualifiers::OCL_Strong: 418 case Qualifiers::OCL_Weak: 419 info.NeedsCopyDispose = true; 420 } 421 422 // Block pointers require copy/dispose. So do Objective-C pointers. 423 } else if (variable->getType()->isObjCRetainableType()) { 424 info.NeedsCopyDispose = true; 425 // used for mrr below. 426 lifetime = Qualifiers::OCL_Strong; 427 428 // So do types that require non-trivial copy construction. 429 } else if (CI.hasCopyExpr()) { 430 info.NeedsCopyDispose = true; 431 info.HasCXXObject = true; 432 433 // And so do types with destructors. 434 } else if (CGM.getLangOpts().CPlusPlus) { 435 if (const CXXRecordDecl *record = 436 variable->getType()->getAsCXXRecordDecl()) { 437 if (!record->hasTrivialDestructor()) { 438 info.HasCXXObject = true; 439 info.NeedsCopyDispose = true; 440 } 441 } 442 } 443 444 QualType VT = variable->getType(); 445 CharUnits size = C.getTypeSizeInChars(VT); 446 CharUnits align = C.getDeclAlign(variable); 447 448 maxFieldAlign = std::max(maxFieldAlign, align); 449 450 llvm::Type *llvmType = 451 CGM.getTypes().ConvertTypeForMem(VT); 452 453 layout.push_back(BlockLayoutChunk(align, size, lifetime, &CI, llvmType)); 454 } 455 456 // If that was everything, we're done here. 457 if (layout.empty()) { 458 info.StructureType = 459 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 460 info.CanBeGlobal = true; 461 return; 462 } 463 464 // Sort the layout by alignment. We have to use a stable sort here 465 // to get reproducible results. There should probably be an 466 // llvm::array_pod_stable_sort. 467 std::stable_sort(layout.begin(), layout.end()); 468 469 // Needed for blocks layout info. 470 info.BlockHeaderForcedGapOffset = info.BlockSize; 471 info.BlockHeaderForcedGapSize = CharUnits::Zero(); 472 473 CharUnits &blockSize = info.BlockSize; 474 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign); 475 476 // Assuming that the first byte in the header is maximally aligned, 477 // get the alignment of the first byte following the header. 478 CharUnits endAlign = getLowBit(blockSize); 479 480 // If the end of the header isn't satisfactorily aligned for the 481 // maximum thing, look for things that are okay with the header-end 482 // alignment, and keep appending them until we get something that's 483 // aligned right. This algorithm is only guaranteed optimal if 484 // that condition is satisfied at some point; otherwise we can get 485 // things like: 486 // header // next byte has alignment 4 487 // something_with_size_5; // next byte has alignment 1 488 // something_with_alignment_8; 489 // which has 7 bytes of padding, as opposed to the naive solution 490 // which might have less (?). 491 if (endAlign < maxFieldAlign) { 492 SmallVectorImpl<BlockLayoutChunk>::iterator 493 li = layout.begin() + 1, le = layout.end(); 494 495 // Look for something that the header end is already 496 // satisfactorily aligned for. 497 for (; li != le && endAlign < li->Alignment; ++li) 498 ; 499 500 // If we found something that's naturally aligned for the end of 501 // the header, keep adding things... 502 if (li != le) { 503 SmallVectorImpl<BlockLayoutChunk>::iterator first = li; 504 for (; li != le; ++li) { 505 assert(endAlign >= li->Alignment); 506 507 li->setIndex(info, elementTypes.size()); 508 elementTypes.push_back(li->Type); 509 blockSize += li->Size; 510 endAlign = getLowBit(blockSize); 511 512 // ...until we get to the alignment of the maximum field. 513 if (endAlign >= maxFieldAlign) { 514 if (li == first) { 515 // No user field was appended. So, a gap was added. 516 // Save total gap size for use in block layout bit map. 517 info.BlockHeaderForcedGapSize = li->Size; 518 } 519 break; 520 } 521 } 522 // Don't re-append everything we just appended. 523 layout.erase(first, li); 524 } 525 } 526 527 assert(endAlign == getLowBit(blockSize)); 528 529 // At this point, we just have to add padding if the end align still 530 // isn't aligned right. 531 if (endAlign < maxFieldAlign) { 532 CharUnits newBlockSize = blockSize.RoundUpToAlignment(maxFieldAlign); 533 CharUnits padding = newBlockSize - blockSize; 534 535 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty, 536 padding.getQuantity())); 537 blockSize = newBlockSize; 538 endAlign = getLowBit(blockSize); // might be > maxFieldAlign 539 } 540 541 assert(endAlign >= maxFieldAlign); 542 assert(endAlign == getLowBit(blockSize)); 543 // Slam everything else on now. This works because they have 544 // strictly decreasing alignment and we expect that size is always a 545 // multiple of alignment. 546 for (SmallVectorImpl<BlockLayoutChunk>::iterator 547 li = layout.begin(), le = layout.end(); li != le; ++li) { 548 assert(endAlign >= li->Alignment); 549 li->setIndex(info, elementTypes.size()); 550 elementTypes.push_back(li->Type); 551 blockSize += li->Size; 552 endAlign = getLowBit(blockSize); 553 } 554 555 info.StructureType = 556 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 557} 558 559/// Enter the scope of a block. This should be run at the entrance to 560/// a full-expression so that the block's cleanups are pushed at the 561/// right place in the stack. 562static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) { 563 assert(CGF.HaveInsertPoint()); 564 565 // Allocate the block info and place it at the head of the list. 566 CGBlockInfo &blockInfo = 567 *new CGBlockInfo(block, CGF.CurFn->getName()); 568 blockInfo.NextBlockInfo = CGF.FirstBlockInfo; 569 CGF.FirstBlockInfo = &blockInfo; 570 571 // Compute information about the layout, etc., of this block, 572 // pushing cleanups as necessary. 573 computeBlockInfo(CGF.CGM, &CGF, blockInfo); 574 575 // Nothing else to do if it can be global. 576 if (blockInfo.CanBeGlobal) return; 577 578 // Make the allocation for the block. 579 blockInfo.Address = 580 CGF.CreateTempAlloca(blockInfo.StructureType, "block"); 581 blockInfo.Address->setAlignment(blockInfo.BlockAlign.getQuantity()); 582 583 // If there are cleanups to emit, enter them (but inactive). 584 if (!blockInfo.NeedsCopyDispose) return; 585 586 // Walk through the captures (in order) and find the ones not 587 // captured by constant. 588 for (const auto &CI : block->captures()) { 589 // Ignore __block captures; there's nothing special in the 590 // on-stack block that we need to do for them. 591 if (CI.isByRef()) continue; 592 593 // Ignore variables that are constant-captured. 594 const VarDecl *variable = CI.getVariable(); 595 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 596 if (capture.isConstant()) continue; 597 598 // Ignore objects that aren't destructed. 599 QualType::DestructionKind dtorKind = 600 variable->getType().isDestructedType(); 601 if (dtorKind == QualType::DK_none) continue; 602 603 CodeGenFunction::Destroyer *destroyer; 604 605 // Block captures count as local values and have imprecise semantics. 606 // They also can't be arrays, so need to worry about that. 607 if (dtorKind == QualType::DK_objc_strong_lifetime) { 608 destroyer = CodeGenFunction::destroyARCStrongImprecise; 609 } else { 610 destroyer = CGF.getDestroyer(dtorKind); 611 } 612 613 // GEP down to the address. 614 llvm::Value *addr = CGF.Builder.CreateStructGEP(blockInfo.Address, 615 capture.getIndex()); 616 617 // We can use that GEP as the dominating IP. 618 if (!blockInfo.DominatingIP) 619 blockInfo.DominatingIP = cast<llvm::Instruction>(addr); 620 621 CleanupKind cleanupKind = InactiveNormalCleanup; 622 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind); 623 if (useArrayEHCleanup) 624 cleanupKind = InactiveNormalAndEHCleanup; 625 626 CGF.pushDestroy(cleanupKind, addr, variable->getType(), 627 destroyer, useArrayEHCleanup); 628 629 // Remember where that cleanup was. 630 capture.setCleanup(CGF.EHStack.stable_begin()); 631 } 632} 633 634/// Enter a full-expression with a non-trivial number of objects to 635/// clean up. This is in this file because, at the moment, the only 636/// kind of cleanup object is a BlockDecl*. 637void CodeGenFunction::enterNonTrivialFullExpression(const ExprWithCleanups *E) { 638 assert(E->getNumObjects() != 0); 639 ArrayRef<ExprWithCleanups::CleanupObject> cleanups = E->getObjects(); 640 for (ArrayRef<ExprWithCleanups::CleanupObject>::iterator 641 i = cleanups.begin(), e = cleanups.end(); i != e; ++i) { 642 enterBlockScope(*this, *i); 643 } 644} 645 646/// Find the layout for the given block in a linked list and remove it. 647static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head, 648 const BlockDecl *block) { 649 while (true) { 650 assert(head && *head); 651 CGBlockInfo *cur = *head; 652 653 // If this is the block we're looking for, splice it out of the list. 654 if (cur->getBlockDecl() == block) { 655 *head = cur->NextBlockInfo; 656 return cur; 657 } 658 659 head = &cur->NextBlockInfo; 660 } 661} 662 663/// Destroy a chain of block layouts. 664void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) { 665 assert(head && "destroying an empty chain"); 666 do { 667 CGBlockInfo *cur = head; 668 head = cur->NextBlockInfo; 669 delete cur; 670 } while (head != nullptr); 671} 672 673/// Emit a block literal expression in the current function. 674llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) { 675 // If the block has no captures, we won't have a pre-computed 676 // layout for it. 677 if (!blockExpr->getBlockDecl()->hasCaptures()) { 678 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName()); 679 computeBlockInfo(CGM, this, blockInfo); 680 blockInfo.BlockExpression = blockExpr; 681 return EmitBlockLiteral(blockInfo); 682 } 683 684 // Find the block info for this block and take ownership of it. 685 std::unique_ptr<CGBlockInfo> blockInfo; 686 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo, 687 blockExpr->getBlockDecl())); 688 689 blockInfo->BlockExpression = blockExpr; 690 return EmitBlockLiteral(*blockInfo); 691} 692 693llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) { 694 // Using the computed layout, generate the actual block function. 695 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda(); 696 llvm::Constant *blockFn 697 = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo, 698 LocalDeclMap, 699 isLambdaConv); 700 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); 701 702 // If there is nothing to capture, we can emit this as a global block. 703 if (blockInfo.CanBeGlobal) 704 return buildGlobalBlock(CGM, blockInfo, blockFn); 705 706 // Otherwise, we have to emit this as a local block. 707 708 llvm::Constant *isa = CGM.getNSConcreteStackBlock(); 709 isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy); 710 711 // Build the block descriptor. 712 llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo); 713 714 llvm::AllocaInst *blockAddr = blockInfo.Address; 715 assert(blockAddr && "block has no address!"); 716 717 // Compute the initial on-stack block flags. 718 BlockFlags flags = BLOCK_HAS_SIGNATURE; 719 if (blockInfo.HasCapturedVariableLayout) flags |= BLOCK_HAS_EXTENDED_LAYOUT; 720 if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE; 721 if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ; 722 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; 723 724 // Initialize the block literal. 725 Builder.CreateStore(isa, Builder.CreateStructGEP(blockAddr, 0, "block.isa")); 726 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 727 Builder.CreateStructGEP(blockAddr, 1, "block.flags")); 728 Builder.CreateStore(llvm::ConstantInt::get(IntTy, 0), 729 Builder.CreateStructGEP(blockAddr, 2, "block.reserved")); 730 Builder.CreateStore(blockFn, Builder.CreateStructGEP(blockAddr, 3, 731 "block.invoke")); 732 Builder.CreateStore(descriptor, Builder.CreateStructGEP(blockAddr, 4, 733 "block.descriptor")); 734 735 // Finally, capture all the values into the block. 736 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 737 738 // First, 'this'. 739 if (blockDecl->capturesCXXThis()) { 740 llvm::Value *addr = Builder.CreateStructGEP(blockAddr, 741 blockInfo.CXXThisIndex, 742 "block.captured-this.addr"); 743 Builder.CreateStore(LoadCXXThis(), addr); 744 } 745 746 // Next, captured variables. 747 for (const auto &CI : blockDecl->captures()) { 748 const VarDecl *variable = CI.getVariable(); 749 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 750 751 // Ignore constant captures. 752 if (capture.isConstant()) continue; 753 754 QualType type = variable->getType(); 755 CharUnits align = getContext().getDeclAlign(variable); 756 757 // This will be a [[type]]*, except that a byref entry will just be 758 // an i8**. 759 llvm::Value *blockField = 760 Builder.CreateStructGEP(blockAddr, capture.getIndex(), 761 "block.captured"); 762 763 // Compute the address of the thing we're going to move into the 764 // block literal. 765 llvm::Value *src; 766 if (BlockInfo && CI.isNested()) { 767 // We need to use the capture from the enclosing block. 768 const CGBlockInfo::Capture &enclosingCapture = 769 BlockInfo->getCapture(variable); 770 771 // This is a [[type]]*, except that a byref entry wil just be an i8**. 772 src = Builder.CreateStructGEP(LoadBlockStruct(), 773 enclosingCapture.getIndex(), 774 "block.capture.addr"); 775 } else if (blockDecl->isConversionFromLambda()) { 776 // The lambda capture in a lambda's conversion-to-block-pointer is 777 // special; we'll simply emit it directly. 778 src = nullptr; 779 } else { 780 // Just look it up in the locals map, which will give us back a 781 // [[type]]*. If that doesn't work, do the more elaborate DRE 782 // emission. 783 src = LocalDeclMap.lookup(variable); 784 if (!src) { 785 DeclRefExpr declRef(const_cast<VarDecl *>(variable), 786 /*refersToEnclosing*/ CI.isNested(), type, 787 VK_LValue, SourceLocation()); 788 src = EmitDeclRefLValue(&declRef).getAddress(); 789 } 790 } 791 792 // For byrefs, we just write the pointer to the byref struct into 793 // the block field. There's no need to chase the forwarding 794 // pointer at this point, since we're building something that will 795 // live a shorter life than the stack byref anyway. 796 if (CI.isByRef()) { 797 // Get a void* that points to the byref struct. 798 if (CI.isNested()) 799 src = Builder.CreateAlignedLoad(src, align.getQuantity(), 800 "byref.capture"); 801 else 802 src = Builder.CreateBitCast(src, VoidPtrTy); 803 804 // Write that void* into the capture field. 805 Builder.CreateAlignedStore(src, blockField, align.getQuantity()); 806 807 // If we have a copy constructor, evaluate that into the block field. 808 } else if (const Expr *copyExpr = CI.getCopyExpr()) { 809 if (blockDecl->isConversionFromLambda()) { 810 // If we have a lambda conversion, emit the expression 811 // directly into the block instead. 812 AggValueSlot Slot = 813 AggValueSlot::forAddr(blockField, align, Qualifiers(), 814 AggValueSlot::IsDestructed, 815 AggValueSlot::DoesNotNeedGCBarriers, 816 AggValueSlot::IsNotAliased); 817 EmitAggExpr(copyExpr, Slot); 818 } else { 819 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr); 820 } 821 822 // If it's a reference variable, copy the reference into the block field. 823 } else if (type->isReferenceType()) { 824 llvm::Value *ref = 825 Builder.CreateAlignedLoad(src, align.getQuantity(), "ref.val"); 826 Builder.CreateAlignedStore(ref, blockField, align.getQuantity()); 827 828 // If this is an ARC __strong block-pointer variable, don't do a 829 // block copy. 830 // 831 // TODO: this can be generalized into the normal initialization logic: 832 // we should never need to do a block-copy when initializing a local 833 // variable, because the local variable's lifetime should be strictly 834 // contained within the stack block's. 835 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong && 836 type->isBlockPointerType()) { 837 // Load the block and do a simple retain. 838 LValue srcLV = MakeAddrLValue(src, type, align); 839 llvm::Value *value = EmitLoadOfScalar(srcLV, SourceLocation()); 840 value = EmitARCRetainNonBlock(value); 841 842 // Do a primitive store to the block field. 843 LValue destLV = MakeAddrLValue(blockField, type, align); 844 EmitStoreOfScalar(value, destLV, /*init*/ true); 845 846 // Otherwise, fake up a POD copy into the block field. 847 } else { 848 // Fake up a new variable so that EmitScalarInit doesn't think 849 // we're referring to the variable in its own initializer. 850 ImplicitParamDecl blockFieldPseudoVar(getContext(), /*DC*/ nullptr, 851 SourceLocation(), /*name*/ nullptr, 852 type); 853 854 // We use one of these or the other depending on whether the 855 // reference is nested. 856 DeclRefExpr declRef(const_cast<VarDecl*>(variable), 857 /*refersToEnclosing*/ CI.isNested(), type, 858 VK_LValue, SourceLocation()); 859 860 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue, 861 &declRef, VK_RValue); 862 EmitExprAsInit(&l2r, &blockFieldPseudoVar, 863 MakeAddrLValue(blockField, type, align), 864 /*captured by init*/ false); 865 } 866 867 // Activate the cleanup if layout pushed one. 868 if (!CI.isByRef()) { 869 EHScopeStack::stable_iterator cleanup = capture.getCleanup(); 870 if (cleanup.isValid()) 871 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP); 872 } 873 } 874 875 // Cast to the converted block-pointer type, which happens (somewhat 876 // unfortunately) to be a pointer to function type. 877 llvm::Value *result = 878 Builder.CreateBitCast(blockAddr, 879 ConvertType(blockInfo.getBlockExpr()->getType())); 880 881 return result; 882} 883 884 885llvm::Type *CodeGenModule::getBlockDescriptorType() { 886 if (BlockDescriptorType) 887 return BlockDescriptorType; 888 889 llvm::Type *UnsignedLongTy = 890 getTypes().ConvertType(getContext().UnsignedLongTy); 891 892 // struct __block_descriptor { 893 // unsigned long reserved; 894 // unsigned long block_size; 895 // 896 // // later, the following will be added 897 // 898 // struct { 899 // void (*copyHelper)(); 900 // void (*copyHelper)(); 901 // } helpers; // !!! optional 902 // 903 // const char *signature; // the block signature 904 // const char *layout; // reserved 905 // }; 906 BlockDescriptorType = 907 llvm::StructType::create("struct.__block_descriptor", 908 UnsignedLongTy, UnsignedLongTy, NULL); 909 910 // Now form a pointer to that. 911 BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType); 912 return BlockDescriptorType; 913} 914 915llvm::Type *CodeGenModule::getGenericBlockLiteralType() { 916 if (GenericBlockLiteralType) 917 return GenericBlockLiteralType; 918 919 llvm::Type *BlockDescPtrTy = getBlockDescriptorType(); 920 921 // struct __block_literal_generic { 922 // void *__isa; 923 // int __flags; 924 // int __reserved; 925 // void (*__invoke)(void *); 926 // struct __block_descriptor *__descriptor; 927 // }; 928 GenericBlockLiteralType = 929 llvm::StructType::create("struct.__block_literal_generic", 930 VoidPtrTy, IntTy, IntTy, VoidPtrTy, 931 BlockDescPtrTy, NULL); 932 933 return GenericBlockLiteralType; 934} 935 936 937RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E, 938 ReturnValueSlot ReturnValue) { 939 const BlockPointerType *BPT = 940 E->getCallee()->getType()->getAs<BlockPointerType>(); 941 942 llvm::Value *Callee = EmitScalarExpr(E->getCallee()); 943 944 // Get a pointer to the generic block literal. 945 llvm::Type *BlockLiteralTy = 946 llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType()); 947 948 // Bitcast the callee to a block literal. 949 llvm::Value *BlockLiteral = 950 Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal"); 951 952 // Get the function pointer from the literal. 953 llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3); 954 955 BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy); 956 957 // Add the block literal. 958 CallArgList Args; 959 Args.add(RValue::get(BlockLiteral), getContext().VoidPtrTy); 960 961 QualType FnType = BPT->getPointeeType(); 962 963 // And the rest of the arguments. 964 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), 965 E->arg_begin(), E->arg_end()); 966 967 // Load the function. 968 llvm::Value *Func = Builder.CreateLoad(FuncPtr); 969 970 const FunctionType *FuncTy = FnType->castAs<FunctionType>(); 971 const CGFunctionInfo &FnInfo = 972 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy); 973 974 // Cast the function pointer to the right type. 975 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo); 976 977 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy); 978 Func = Builder.CreateBitCast(Func, BlockFTyPtr); 979 980 // And call the block. 981 return EmitCall(FnInfo, Func, ReturnValue, Args); 982} 983 984llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable, 985 bool isByRef) { 986 assert(BlockInfo && "evaluating block ref without block information?"); 987 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable); 988 989 // Handle constant captures. 990 if (capture.isConstant()) return LocalDeclMap[variable]; 991 992 llvm::Value *addr = 993 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(), 994 "block.capture.addr"); 995 996 if (isByRef) { 997 // addr should be a void** right now. Load, then cast the result 998 // to byref*. 999 1000 addr = Builder.CreateLoad(addr); 1001 llvm::PointerType *byrefPointerType 1002 = llvm::PointerType::get(BuildByRefType(variable), 0); 1003 addr = Builder.CreateBitCast(addr, byrefPointerType, 1004 "byref.addr"); 1005 1006 // Follow the forwarding pointer. 1007 addr = Builder.CreateStructGEP(addr, 1, "byref.forwarding"); 1008 addr = Builder.CreateLoad(addr, "byref.addr.forwarded"); 1009 1010 // Cast back to byref* and GEP over to the actual object. 1011 addr = Builder.CreateBitCast(addr, byrefPointerType); 1012 addr = Builder.CreateStructGEP(addr, getByRefValueLLVMField(variable), 1013 variable->getNameAsString()); 1014 } 1015 1016 if (variable->getType()->isReferenceType()) 1017 addr = Builder.CreateLoad(addr, "ref.tmp"); 1018 1019 return addr; 1020} 1021 1022llvm::Constant * 1023CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *blockExpr, 1024 const char *name) { 1025 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), name); 1026 blockInfo.BlockExpression = blockExpr; 1027 1028 // Compute information about the layout, etc., of this block. 1029 computeBlockInfo(*this, nullptr, blockInfo); 1030 1031 // Using that metadata, generate the actual block function. 1032 llvm::Constant *blockFn; 1033 { 1034 llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap; 1035 blockFn = CodeGenFunction(*this).GenerateBlockFunction(GlobalDecl(), 1036 blockInfo, 1037 LocalDeclMap, 1038 false); 1039 } 1040 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); 1041 1042 return buildGlobalBlock(*this, blockInfo, blockFn); 1043} 1044 1045static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, 1046 const CGBlockInfo &blockInfo, 1047 llvm::Constant *blockFn) { 1048 assert(blockInfo.CanBeGlobal); 1049 1050 // Generate the constants for the block literal initializer. 1051 llvm::Constant *fields[BlockHeaderSize]; 1052 1053 // isa 1054 fields[0] = CGM.getNSConcreteGlobalBlock(); 1055 1056 // __flags 1057 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE; 1058 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; 1059 1060 fields[1] = llvm::ConstantInt::get(CGM.IntTy, flags.getBitMask()); 1061 1062 // Reserved 1063 fields[2] = llvm::Constant::getNullValue(CGM.IntTy); 1064 1065 // Function 1066 fields[3] = blockFn; 1067 1068 // Descriptor 1069 fields[4] = buildBlockDescriptor(CGM, blockInfo); 1070 1071 llvm::Constant *init = llvm::ConstantStruct::getAnon(fields); 1072 1073 llvm::GlobalVariable *literal = 1074 new llvm::GlobalVariable(CGM.getModule(), 1075 init->getType(), 1076 /*constant*/ true, 1077 llvm::GlobalVariable::InternalLinkage, 1078 init, 1079 "__block_literal_global"); 1080 literal->setAlignment(blockInfo.BlockAlign.getQuantity()); 1081 1082 // Return a constant of the appropriately-casted type. 1083 llvm::Type *requiredType = 1084 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType()); 1085 return llvm::ConstantExpr::getBitCast(literal, requiredType); 1086} 1087 1088llvm::Function * 1089CodeGenFunction::GenerateBlockFunction(GlobalDecl GD, 1090 const CGBlockInfo &blockInfo, 1091 const DeclMapTy &ldm, 1092 bool IsLambdaConversionToBlock) { 1093 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1094 1095 CurGD = GD; 1096 1097 BlockInfo = &blockInfo; 1098 1099 // Arrange for local static and local extern declarations to appear 1100 // to be local to this function as well, in case they're directly 1101 // referenced in a block. 1102 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) { 1103 const auto *var = dyn_cast<VarDecl>(i->first); 1104 if (var && !var->hasLocalStorage()) 1105 LocalDeclMap[var] = i->second; 1106 } 1107 1108 // Begin building the function declaration. 1109 1110 // Build the argument list. 1111 FunctionArgList args; 1112 1113 // The first argument is the block pointer. Just take it as a void* 1114 // and cast it later. 1115 QualType selfTy = getContext().VoidPtrTy; 1116 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor"); 1117 1118 ImplicitParamDecl selfDecl(getContext(), const_cast<BlockDecl*>(blockDecl), 1119 SourceLocation(), II, selfTy); 1120 args.push_back(&selfDecl); 1121 1122 // Now add the rest of the parameters. 1123 for (auto i : blockDecl->params()) 1124 args.push_back(i); 1125 1126 // Create the function declaration. 1127 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType(); 1128 const CGFunctionInfo &fnInfo = CGM.getTypes().arrangeFreeFunctionDeclaration( 1129 fnType->getReturnType(), args, fnType->getExtInfo(), 1130 fnType->isVariadic()); 1131 if (CGM.ReturnSlotInterferesWithArgs(fnInfo)) 1132 blockInfo.UsesStret = true; 1133 1134 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo); 1135 1136 StringRef name = CGM.getBlockMangledName(GD, blockDecl); 1137 llvm::Function *fn = llvm::Function::Create( 1138 fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule()); 1139 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo); 1140 1141 // Begin generating the function. 1142 StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args, 1143 blockDecl->getLocation(), 1144 blockInfo.getBlockExpr()->getBody()->getLocStart()); 1145 1146 // Okay. Undo some of what StartFunction did. 1147 1148 // Pull the 'self' reference out of the local decl map. 1149 llvm::Value *blockAddr = LocalDeclMap[&selfDecl]; 1150 LocalDeclMap.erase(&selfDecl); 1151 BlockPointer = Builder.CreateBitCast(blockAddr, 1152 blockInfo.StructureType->getPointerTo(), 1153 "block"); 1154 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA 1155 // won't delete the dbg.declare intrinsics for captured variables. 1156 llvm::Value *BlockPointerDbgLoc = BlockPointer; 1157 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1158 // Allocate a stack slot for it, so we can point the debugger to it 1159 llvm::AllocaInst *Alloca = CreateTempAlloca(BlockPointer->getType(), 1160 "block.addr"); 1161 unsigned Align = getContext().getDeclAlign(&selfDecl).getQuantity(); 1162 Alloca->setAlignment(Align); 1163 // Set the DebugLocation to empty, so the store is recognized as a 1164 // frame setup instruction by llvm::DwarfDebug::beginFunction(). 1165 NoLocation NL(*this, Builder); 1166 Builder.CreateAlignedStore(BlockPointer, Alloca, Align); 1167 BlockPointerDbgLoc = Alloca; 1168 } 1169 1170 // If we have a C++ 'this' reference, go ahead and force it into 1171 // existence now. 1172 if (blockDecl->capturesCXXThis()) { 1173 llvm::Value *addr = Builder.CreateStructGEP(BlockPointer, 1174 blockInfo.CXXThisIndex, 1175 "block.captured-this"); 1176 CXXThisValue = Builder.CreateLoad(addr, "this"); 1177 } 1178 1179 // Also force all the constant captures. 1180 for (const auto &CI : blockDecl->captures()) { 1181 const VarDecl *variable = CI.getVariable(); 1182 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1183 if (!capture.isConstant()) continue; 1184 1185 unsigned align = getContext().getDeclAlign(variable).getQuantity(); 1186 1187 llvm::AllocaInst *alloca = 1188 CreateMemTemp(variable->getType(), "block.captured-const"); 1189 alloca->setAlignment(align); 1190 1191 Builder.CreateAlignedStore(capture.getConstant(), alloca, align); 1192 1193 LocalDeclMap[variable] = alloca; 1194 } 1195 1196 // Save a spot to insert the debug information for all the DeclRefExprs. 1197 llvm::BasicBlock *entry = Builder.GetInsertBlock(); 1198 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); 1199 --entry_ptr; 1200 1201 if (IsLambdaConversionToBlock) 1202 EmitLambdaBlockInvokeBody(); 1203 else { 1204 PGO.assignRegionCounters(blockDecl, fn); 1205 RegionCounter Cnt = getPGORegionCounter(blockDecl->getBody()); 1206 Cnt.beginRegion(Builder); 1207 EmitStmt(blockDecl->getBody()); 1208 PGO.emitInstrumentationData(); 1209 PGO.destroyRegionCounters(); 1210 } 1211 1212 // Remember where we were... 1213 llvm::BasicBlock *resume = Builder.GetInsertBlock(); 1214 1215 // Go back to the entry. 1216 ++entry_ptr; 1217 Builder.SetInsertPoint(entry, entry_ptr); 1218 1219 // Emit debug information for all the DeclRefExprs. 1220 // FIXME: also for 'this' 1221 if (CGDebugInfo *DI = getDebugInfo()) { 1222 for (const auto &CI : blockDecl->captures()) { 1223 const VarDecl *variable = CI.getVariable(); 1224 DI->EmitLocation(Builder, variable->getLocation()); 1225 1226 if (CGM.getCodeGenOpts().getDebugInfo() 1227 >= CodeGenOptions::LimitedDebugInfo) { 1228 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1229 if (capture.isConstant()) { 1230 DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], 1231 Builder); 1232 continue; 1233 } 1234 1235 DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointerDbgLoc, 1236 Builder, blockInfo); 1237 } 1238 } 1239 // Recover location if it was changed in the above loop. 1240 DI->EmitLocation(Builder, 1241 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1242 } 1243 1244 // And resume where we left off. 1245 if (resume == nullptr) 1246 Builder.ClearInsertionPoint(); 1247 else 1248 Builder.SetInsertPoint(resume); 1249 1250 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1251 1252 return fn; 1253} 1254 1255/* 1256 notes.push_back(HelperInfo()); 1257 HelperInfo ¬e = notes.back(); 1258 note.index = capture.getIndex(); 1259 note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type)); 1260 note.cxxbar_import = ci->getCopyExpr(); 1261 1262 if (ci->isByRef()) { 1263 note.flag = BLOCK_FIELD_IS_BYREF; 1264 if (type.isObjCGCWeak()) 1265 note.flag |= BLOCK_FIELD_IS_WEAK; 1266 } else if (type->isBlockPointerType()) { 1267 note.flag = BLOCK_FIELD_IS_BLOCK; 1268 } else { 1269 note.flag = BLOCK_FIELD_IS_OBJECT; 1270 } 1271 */ 1272 1273 1274/// Generate the copy-helper function for a block closure object: 1275/// static void block_copy_helper(block_t *dst, block_t *src); 1276/// The runtime will have previously initialized 'dst' by doing a 1277/// bit-copy of 'src'. 1278/// 1279/// Note that this copies an entire block closure object to the heap; 1280/// it should not be confused with a 'byref copy helper', which moves 1281/// the contents of an individual __block variable to the heap. 1282llvm::Constant * 1283CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) { 1284 ASTContext &C = getContext(); 1285 1286 FunctionArgList args; 1287 ImplicitParamDecl dstDecl(getContext(), nullptr, SourceLocation(), nullptr, 1288 C.VoidPtrTy); 1289 args.push_back(&dstDecl); 1290 ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr, 1291 C.VoidPtrTy); 1292 args.push_back(&srcDecl); 1293 1294 const CGFunctionInfo &FI = CGM.getTypes().arrangeFreeFunctionDeclaration( 1295 C.VoidTy, args, FunctionType::ExtInfo(), /*variadic=*/false); 1296 1297 // FIXME: it would be nice if these were mergeable with things with 1298 // identical semantics. 1299 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1300 1301 llvm::Function *Fn = 1302 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1303 "__copy_helper_block_", &CGM.getModule()); 1304 1305 IdentifierInfo *II 1306 = &CGM.getContext().Idents.get("__copy_helper_block_"); 1307 1308 FunctionDecl *FD = FunctionDecl::Create(C, 1309 C.getTranslationUnitDecl(), 1310 SourceLocation(), 1311 SourceLocation(), II, C.VoidTy, 1312 nullptr, SC_Static, 1313 false, 1314 false); 1315 // Create a scope with an artificial location for the body of this function. 1316 ArtificialLocation AL(*this, Builder); 1317 StartFunction(FD, C.VoidTy, Fn, FI, args); 1318 AL.Emit(); 1319 1320 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1321 1322 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1323 src = Builder.CreateLoad(src); 1324 src = Builder.CreateBitCast(src, structPtrTy, "block.source"); 1325 1326 llvm::Value *dst = GetAddrOfLocalVar(&dstDecl); 1327 dst = Builder.CreateLoad(dst); 1328 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest"); 1329 1330 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1331 1332 for (const auto &CI : blockDecl->captures()) { 1333 const VarDecl *variable = CI.getVariable(); 1334 QualType type = variable->getType(); 1335 1336 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1337 if (capture.isConstant()) continue; 1338 1339 const Expr *copyExpr = CI.getCopyExpr(); 1340 BlockFieldFlags flags; 1341 1342 bool useARCWeakCopy = false; 1343 bool useARCStrongCopy = false; 1344 1345 if (copyExpr) { 1346 assert(!CI.isByRef()); 1347 // don't bother computing flags 1348 1349 } else if (CI.isByRef()) { 1350 flags = BLOCK_FIELD_IS_BYREF; 1351 if (type.isObjCGCWeak()) 1352 flags |= BLOCK_FIELD_IS_WEAK; 1353 1354 } else if (type->isObjCRetainableType()) { 1355 flags = BLOCK_FIELD_IS_OBJECT; 1356 bool isBlockPointer = type->isBlockPointerType(); 1357 if (isBlockPointer) 1358 flags = BLOCK_FIELD_IS_BLOCK; 1359 1360 // Special rules for ARC captures: 1361 if (getLangOpts().ObjCAutoRefCount) { 1362 Qualifiers qs = type.getQualifiers(); 1363 1364 // We need to register __weak direct captures with the runtime. 1365 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) { 1366 useARCWeakCopy = true; 1367 1368 // We need to retain the copied value for __strong direct captures. 1369 } else if (qs.getObjCLifetime() == Qualifiers::OCL_Strong) { 1370 // If it's a block pointer, we have to copy the block and 1371 // assign that to the destination pointer, so we might as 1372 // well use _Block_object_assign. Otherwise we can avoid that. 1373 if (!isBlockPointer) 1374 useARCStrongCopy = true; 1375 1376 // Otherwise the memcpy is fine. 1377 } else { 1378 continue; 1379 } 1380 1381 // Non-ARC captures of retainable pointers are strong and 1382 // therefore require a call to _Block_object_assign. 1383 } else { 1384 // fall through 1385 } 1386 } else { 1387 continue; 1388 } 1389 1390 unsigned index = capture.getIndex(); 1391 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1392 llvm::Value *dstField = Builder.CreateStructGEP(dst, index); 1393 1394 // If there's an explicit copy expression, we do that. 1395 if (copyExpr) { 1396 EmitSynthesizedCXXCopyCtor(dstField, srcField, copyExpr); 1397 } else if (useARCWeakCopy) { 1398 EmitARCCopyWeak(dstField, srcField); 1399 } else { 1400 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src"); 1401 if (useARCStrongCopy) { 1402 // At -O0, store null into the destination field (so that the 1403 // storeStrong doesn't over-release) and then call storeStrong. 1404 // This is a workaround to not having an initStrong call. 1405 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1406 auto *ty = cast<llvm::PointerType>(srcValue->getType()); 1407 llvm::Value *null = llvm::ConstantPointerNull::get(ty); 1408 Builder.CreateStore(null, dstField); 1409 EmitARCStoreStrongCall(dstField, srcValue, true); 1410 1411 // With optimization enabled, take advantage of the fact that 1412 // the blocks runtime guarantees a memcpy of the block data, and 1413 // just emit a retain of the src field. 1414 } else { 1415 EmitARCRetainNonBlock(srcValue); 1416 1417 // We don't need this anymore, so kill it. It's not quite 1418 // worth the annoyance to avoid creating it in the first place. 1419 cast<llvm::Instruction>(dstField)->eraseFromParent(); 1420 } 1421 } else { 1422 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy); 1423 llvm::Value *dstAddr = Builder.CreateBitCast(dstField, VoidPtrTy); 1424 llvm::Value *args[] = { 1425 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 1426 }; 1427 1428 bool copyCanThrow = false; 1429 if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) { 1430 const Expr *copyExpr = 1431 CGM.getContext().getBlockVarCopyInits(variable); 1432 if (copyExpr) { 1433 copyCanThrow = true; // FIXME: reuse the noexcept logic 1434 } 1435 } 1436 1437 if (copyCanThrow) { 1438 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args); 1439 } else { 1440 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args); 1441 } 1442 } 1443 } 1444 } 1445 1446 FinishFunction(); 1447 1448 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1449} 1450 1451/// Generate the destroy-helper function for a block closure object: 1452/// static void block_destroy_helper(block_t *theBlock); 1453/// 1454/// Note that this destroys a heap-allocated block closure object; 1455/// it should not be confused with a 'byref destroy helper', which 1456/// destroys the heap-allocated contents of an individual __block 1457/// variable. 1458llvm::Constant * 1459CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { 1460 ASTContext &C = getContext(); 1461 1462 FunctionArgList args; 1463 ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr, 1464 C.VoidPtrTy); 1465 args.push_back(&srcDecl); 1466 1467 const CGFunctionInfo &FI = CGM.getTypes().arrangeFreeFunctionDeclaration( 1468 C.VoidTy, args, FunctionType::ExtInfo(), /*variadic=*/false); 1469 1470 // FIXME: We'd like to put these into a mergable by content, with 1471 // internal linkage. 1472 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1473 1474 llvm::Function *Fn = 1475 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1476 "__destroy_helper_block_", &CGM.getModule()); 1477 1478 IdentifierInfo *II 1479 = &CGM.getContext().Idents.get("__destroy_helper_block_"); 1480 1481 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), 1482 SourceLocation(), 1483 SourceLocation(), II, C.VoidTy, 1484 nullptr, SC_Static, 1485 false, false); 1486 // Create a scope with an artificial location for the body of this function. 1487 ArtificialLocation AL(*this, Builder); 1488 StartFunction(FD, C.VoidTy, Fn, FI, args); 1489 AL.Emit(); 1490 1491 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1492 1493 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1494 src = Builder.CreateLoad(src); 1495 src = Builder.CreateBitCast(src, structPtrTy, "block"); 1496 1497 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1498 1499 CodeGenFunction::RunCleanupsScope cleanups(*this); 1500 1501 for (const auto &CI : blockDecl->captures()) { 1502 const VarDecl *variable = CI.getVariable(); 1503 QualType type = variable->getType(); 1504 1505 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1506 if (capture.isConstant()) continue; 1507 1508 BlockFieldFlags flags; 1509 const CXXDestructorDecl *dtor = nullptr; 1510 1511 bool useARCWeakDestroy = false; 1512 bool useARCStrongDestroy = false; 1513 1514 if (CI.isByRef()) { 1515 flags = BLOCK_FIELD_IS_BYREF; 1516 if (type.isObjCGCWeak()) 1517 flags |= BLOCK_FIELD_IS_WEAK; 1518 } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1519 if (record->hasTrivialDestructor()) 1520 continue; 1521 dtor = record->getDestructor(); 1522 } else if (type->isObjCRetainableType()) { 1523 flags = BLOCK_FIELD_IS_OBJECT; 1524 if (type->isBlockPointerType()) 1525 flags = BLOCK_FIELD_IS_BLOCK; 1526 1527 // Special rules for ARC captures. 1528 if (getLangOpts().ObjCAutoRefCount) { 1529 Qualifiers qs = type.getQualifiers(); 1530 1531 // Don't generate special dispose logic for a captured object 1532 // unless it's __strong or __weak. 1533 if (!qs.hasStrongOrWeakObjCLifetime()) 1534 continue; 1535 1536 // Support __weak direct captures. 1537 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) 1538 useARCWeakDestroy = true; 1539 1540 // Tools really want us to use objc_storeStrong here. 1541 else 1542 useARCStrongDestroy = true; 1543 } 1544 } else { 1545 continue; 1546 } 1547 1548 unsigned index = capture.getIndex(); 1549 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1550 1551 // If there's an explicit copy expression, we do that. 1552 if (dtor) { 1553 PushDestructorCleanup(dtor, srcField); 1554 1555 // If this is a __weak capture, emit the release directly. 1556 } else if (useARCWeakDestroy) { 1557 EmitARCDestroyWeak(srcField); 1558 1559 // Destroy strong objects with a call if requested. 1560 } else if (useARCStrongDestroy) { 1561 EmitARCDestroyStrong(srcField, ARCImpreciseLifetime); 1562 1563 // Otherwise we call _Block_object_dispose. It wouldn't be too 1564 // hard to just emit this as a cleanup if we wanted to make sure 1565 // that things were done in reverse. 1566 } else { 1567 llvm::Value *value = Builder.CreateLoad(srcField); 1568 value = Builder.CreateBitCast(value, VoidPtrTy); 1569 BuildBlockRelease(value, flags); 1570 } 1571 } 1572 1573 cleanups.ForceCleanup(); 1574 1575 FinishFunction(); 1576 1577 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1578} 1579 1580namespace { 1581 1582/// Emits the copy/dispose helper functions for a __block object of id type. 1583class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers { 1584 BlockFieldFlags Flags; 1585 1586public: 1587 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags) 1588 : ByrefHelpers(alignment), Flags(flags) {} 1589 1590 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1591 llvm::Value *srcField) override { 1592 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy); 1593 1594 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy); 1595 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField); 1596 1597 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask(); 1598 1599 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags); 1600 llvm::Value *fn = CGF.CGM.getBlockObjectAssign(); 1601 1602 llvm::Value *args[] = { destField, srcValue, flagsVal }; 1603 CGF.EmitNounwindRuntimeCall(fn, args); 1604 } 1605 1606 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override { 1607 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0)); 1608 llvm::Value *value = CGF.Builder.CreateLoad(field); 1609 1610 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER); 1611 } 1612 1613 void profileImpl(llvm::FoldingSetNodeID &id) const override { 1614 id.AddInteger(Flags.getBitMask()); 1615 } 1616}; 1617 1618/// Emits the copy/dispose helpers for an ARC __block __weak variable. 1619class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers { 1620public: 1621 ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1622 1623 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1624 llvm::Value *srcField) override { 1625 CGF.EmitARCMoveWeak(destField, srcField); 1626 } 1627 1628 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override { 1629 CGF.EmitARCDestroyWeak(field); 1630 } 1631 1632 void profileImpl(llvm::FoldingSetNodeID &id) const override { 1633 // 0 is distinguishable from all pointers and byref flags 1634 id.AddInteger(0); 1635 } 1636}; 1637 1638/// Emits the copy/dispose helpers for an ARC __block __strong variable 1639/// that's not of block-pointer type. 1640class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers { 1641public: 1642 ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1643 1644 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1645 llvm::Value *srcField) override { 1646 // Do a "move" by copying the value and then zeroing out the old 1647 // variable. 1648 1649 llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField); 1650 value->setAlignment(Alignment.getQuantity()); 1651 1652 llvm::Value *null = 1653 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType())); 1654 1655 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) { 1656 llvm::StoreInst *store = CGF.Builder.CreateStore(null, destField); 1657 store->setAlignment(Alignment.getQuantity()); 1658 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true); 1659 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true); 1660 return; 1661 } 1662 llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField); 1663 store->setAlignment(Alignment.getQuantity()); 1664 1665 store = CGF.Builder.CreateStore(null, srcField); 1666 store->setAlignment(Alignment.getQuantity()); 1667 } 1668 1669 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override { 1670 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1671 } 1672 1673 void profileImpl(llvm::FoldingSetNodeID &id) const override { 1674 // 1 is distinguishable from all pointers and byref flags 1675 id.AddInteger(1); 1676 } 1677}; 1678 1679/// Emits the copy/dispose helpers for an ARC __block __strong 1680/// variable that's of block-pointer type. 1681class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers { 1682public: 1683 ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1684 1685 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1686 llvm::Value *srcField) override { 1687 // Do the copy with objc_retainBlock; that's all that 1688 // _Block_object_assign would do anyway, and we'd have to pass the 1689 // right arguments to make sure it doesn't get no-op'ed. 1690 llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField); 1691 oldValue->setAlignment(Alignment.getQuantity()); 1692 1693 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true); 1694 1695 llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField); 1696 store->setAlignment(Alignment.getQuantity()); 1697 } 1698 1699 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override { 1700 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1701 } 1702 1703 void profileImpl(llvm::FoldingSetNodeID &id) const override { 1704 // 2 is distinguishable from all pointers and byref flags 1705 id.AddInteger(2); 1706 } 1707}; 1708 1709/// Emits the copy/dispose helpers for a __block variable with a 1710/// nontrivial copy constructor or destructor. 1711class CXXByrefHelpers : public CodeGenModule::ByrefHelpers { 1712 QualType VarType; 1713 const Expr *CopyExpr; 1714 1715public: 1716 CXXByrefHelpers(CharUnits alignment, QualType type, 1717 const Expr *copyExpr) 1718 : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {} 1719 1720 bool needsCopy() const override { return CopyExpr != nullptr; } 1721 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1722 llvm::Value *srcField) override { 1723 if (!CopyExpr) return; 1724 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr); 1725 } 1726 1727 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override { 1728 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin(); 1729 CGF.PushDestructorCleanup(VarType, field); 1730 CGF.PopCleanupBlocks(cleanupDepth); 1731 } 1732 1733 void profileImpl(llvm::FoldingSetNodeID &id) const override { 1734 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr()); 1735 } 1736}; 1737} // end anonymous namespace 1738 1739static llvm::Constant * 1740generateByrefCopyHelper(CodeGenFunction &CGF, 1741 llvm::StructType &byrefType, 1742 unsigned valueFieldIndex, 1743 CodeGenModule::ByrefHelpers &byrefInfo) { 1744 ASTContext &Context = CGF.getContext(); 1745 1746 QualType R = Context.VoidTy; 1747 1748 FunctionArgList args; 1749 ImplicitParamDecl dst(CGF.getContext(), nullptr, SourceLocation(), nullptr, 1750 Context.VoidPtrTy); 1751 args.push_back(&dst); 1752 1753 ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr, 1754 Context.VoidPtrTy); 1755 args.push_back(&src); 1756 1757 const CGFunctionInfo &FI = CGF.CGM.getTypes().arrangeFreeFunctionDeclaration( 1758 R, args, FunctionType::ExtInfo(), /*variadic=*/false); 1759 1760 CodeGenTypes &Types = CGF.CGM.getTypes(); 1761 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1762 1763 // FIXME: We'd like to put these into a mergable by content, with 1764 // internal linkage. 1765 llvm::Function *Fn = 1766 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1767 "__Block_byref_object_copy_", &CGF.CGM.getModule()); 1768 1769 IdentifierInfo *II 1770 = &Context.Idents.get("__Block_byref_object_copy_"); 1771 1772 FunctionDecl *FD = FunctionDecl::Create(Context, 1773 Context.getTranslationUnitDecl(), 1774 SourceLocation(), 1775 SourceLocation(), II, R, nullptr, 1776 SC_Static, 1777 false, false); 1778 1779 CGF.StartFunction(FD, R, Fn, FI, args); 1780 1781 if (byrefInfo.needsCopy()) { 1782 llvm::Type *byrefPtrType = byrefType.getPointerTo(0); 1783 1784 // dst->x 1785 llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst); 1786 destField = CGF.Builder.CreateLoad(destField); 1787 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType); 1788 destField = CGF.Builder.CreateStructGEP(destField, valueFieldIndex, "x"); 1789 1790 // src->x 1791 llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src); 1792 srcField = CGF.Builder.CreateLoad(srcField); 1793 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType); 1794 srcField = CGF.Builder.CreateStructGEP(srcField, valueFieldIndex, "x"); 1795 1796 byrefInfo.emitCopy(CGF, destField, srcField); 1797 } 1798 1799 CGF.FinishFunction(); 1800 1801 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1802} 1803 1804/// Build the copy helper for a __block variable. 1805static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM, 1806 llvm::StructType &byrefType, 1807 unsigned byrefValueIndex, 1808 CodeGenModule::ByrefHelpers &info) { 1809 CodeGenFunction CGF(CGM); 1810 return generateByrefCopyHelper(CGF, byrefType, byrefValueIndex, info); 1811} 1812 1813/// Generate code for a __block variable's dispose helper. 1814static llvm::Constant * 1815generateByrefDisposeHelper(CodeGenFunction &CGF, 1816 llvm::StructType &byrefType, 1817 unsigned byrefValueIndex, 1818 CodeGenModule::ByrefHelpers &byrefInfo) { 1819 ASTContext &Context = CGF.getContext(); 1820 QualType R = Context.VoidTy; 1821 1822 FunctionArgList args; 1823 ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr, 1824 Context.VoidPtrTy); 1825 args.push_back(&src); 1826 1827 const CGFunctionInfo &FI = CGF.CGM.getTypes().arrangeFreeFunctionDeclaration( 1828 R, args, FunctionType::ExtInfo(), /*variadic=*/false); 1829 1830 CodeGenTypes &Types = CGF.CGM.getTypes(); 1831 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1832 1833 // FIXME: We'd like to put these into a mergable by content, with 1834 // internal linkage. 1835 llvm::Function *Fn = 1836 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1837 "__Block_byref_object_dispose_", 1838 &CGF.CGM.getModule()); 1839 1840 IdentifierInfo *II 1841 = &Context.Idents.get("__Block_byref_object_dispose_"); 1842 1843 FunctionDecl *FD = FunctionDecl::Create(Context, 1844 Context.getTranslationUnitDecl(), 1845 SourceLocation(), 1846 SourceLocation(), II, R, nullptr, 1847 SC_Static, 1848 false, false); 1849 CGF.StartFunction(FD, R, Fn, FI, args); 1850 1851 if (byrefInfo.needsDispose()) { 1852 llvm::Value *V = CGF.GetAddrOfLocalVar(&src); 1853 V = CGF.Builder.CreateLoad(V); 1854 V = CGF.Builder.CreateBitCast(V, byrefType.getPointerTo(0)); 1855 V = CGF.Builder.CreateStructGEP(V, byrefValueIndex, "x"); 1856 1857 byrefInfo.emitDispose(CGF, V); 1858 } 1859 1860 CGF.FinishFunction(); 1861 1862 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1863} 1864 1865/// Build the dispose helper for a __block variable. 1866static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM, 1867 llvm::StructType &byrefType, 1868 unsigned byrefValueIndex, 1869 CodeGenModule::ByrefHelpers &info) { 1870 CodeGenFunction CGF(CGM); 1871 return generateByrefDisposeHelper(CGF, byrefType, byrefValueIndex, info); 1872} 1873 1874/// Lazily build the copy and dispose helpers for a __block variable 1875/// with the given information. 1876template <class T> static T *buildByrefHelpers(CodeGenModule &CGM, 1877 llvm::StructType &byrefTy, 1878 unsigned byrefValueIndex, 1879 T &byrefInfo) { 1880 // Increase the field's alignment to be at least pointer alignment, 1881 // since the layout of the byref struct will guarantee at least that. 1882 byrefInfo.Alignment = std::max(byrefInfo.Alignment, 1883 CharUnits::fromQuantity(CGM.PointerAlignInBytes)); 1884 1885 llvm::FoldingSetNodeID id; 1886 byrefInfo.Profile(id); 1887 1888 void *insertPos; 1889 CodeGenModule::ByrefHelpers *node 1890 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos); 1891 if (node) return static_cast<T*>(node); 1892 1893 byrefInfo.CopyHelper = 1894 buildByrefCopyHelper(CGM, byrefTy, byrefValueIndex, byrefInfo); 1895 byrefInfo.DisposeHelper = 1896 buildByrefDisposeHelper(CGM, byrefTy, byrefValueIndex,byrefInfo); 1897 1898 T *copy = new (CGM.getContext()) T(byrefInfo); 1899 CGM.ByrefHelpersCache.InsertNode(copy, insertPos); 1900 return copy; 1901} 1902 1903/// Build the copy and dispose helpers for the given __block variable 1904/// emission. Places the helpers in the global cache. Returns null 1905/// if no helpers are required. 1906CodeGenModule::ByrefHelpers * 1907CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType, 1908 const AutoVarEmission &emission) { 1909 const VarDecl &var = *emission.Variable; 1910 QualType type = var.getType(); 1911 1912 unsigned byrefValueIndex = getByRefValueLLVMField(&var); 1913 1914 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1915 const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var); 1916 if (!copyExpr && record->hasTrivialDestructor()) return nullptr; 1917 1918 CXXByrefHelpers byrefInfo(emission.Alignment, type, copyExpr); 1919 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1920 } 1921 1922 // Otherwise, if we don't have a retainable type, there's nothing to do. 1923 // that the runtime does extra copies. 1924 if (!type->isObjCRetainableType()) return nullptr; 1925 1926 Qualifiers qs = type.getQualifiers(); 1927 1928 // If we have lifetime, that dominates. 1929 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) { 1930 assert(getLangOpts().ObjCAutoRefCount); 1931 1932 switch (lifetime) { 1933 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 1934 1935 // These are just bits as far as the runtime is concerned. 1936 case Qualifiers::OCL_ExplicitNone: 1937 case Qualifiers::OCL_Autoreleasing: 1938 return nullptr; 1939 1940 // Tell the runtime that this is ARC __weak, called by the 1941 // byref routines. 1942 case Qualifiers::OCL_Weak: { 1943 ARCWeakByrefHelpers byrefInfo(emission.Alignment); 1944 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1945 } 1946 1947 // ARC __strong __block variables need to be retained. 1948 case Qualifiers::OCL_Strong: 1949 // Block pointers need to be copied, and there's no direct 1950 // transfer possible. 1951 if (type->isBlockPointerType()) { 1952 ARCStrongBlockByrefHelpers byrefInfo(emission.Alignment); 1953 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1954 1955 // Otherwise, we transfer ownership of the retain from the stack 1956 // to the heap. 1957 } else { 1958 ARCStrongByrefHelpers byrefInfo(emission.Alignment); 1959 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1960 } 1961 } 1962 llvm_unreachable("fell out of lifetime switch!"); 1963 } 1964 1965 BlockFieldFlags flags; 1966 if (type->isBlockPointerType()) { 1967 flags |= BLOCK_FIELD_IS_BLOCK; 1968 } else if (CGM.getContext().isObjCNSObjectType(type) || 1969 type->isObjCObjectPointerType()) { 1970 flags |= BLOCK_FIELD_IS_OBJECT; 1971 } else { 1972 return nullptr; 1973 } 1974 1975 if (type.isObjCGCWeak()) 1976 flags |= BLOCK_FIELD_IS_WEAK; 1977 1978 ObjectByrefHelpers byrefInfo(emission.Alignment, flags); 1979 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1980} 1981 1982unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const { 1983 assert(ByRefValueInfo.count(VD) && "Did not find value!"); 1984 1985 return ByRefValueInfo.find(VD)->second.second; 1986} 1987 1988llvm::Value *CodeGenFunction::BuildBlockByrefAddress(llvm::Value *BaseAddr, 1989 const VarDecl *V) { 1990 llvm::Value *Loc = Builder.CreateStructGEP(BaseAddr, 1, "forwarding"); 1991 Loc = Builder.CreateLoad(Loc); 1992 Loc = Builder.CreateStructGEP(Loc, getByRefValueLLVMField(V), 1993 V->getNameAsString()); 1994 return Loc; 1995} 1996 1997/// BuildByRefType - This routine changes a __block variable declared as T x 1998/// into: 1999/// 2000/// struct { 2001/// void *__isa; 2002/// void *__forwarding; 2003/// int32_t __flags; 2004/// int32_t __size; 2005/// void *__copy_helper; // only if needed 2006/// void *__destroy_helper; // only if needed 2007/// void *__byref_variable_layout;// only if needed 2008/// char padding[X]; // only if needed 2009/// T x; 2010/// } x 2011/// 2012llvm::Type *CodeGenFunction::BuildByRefType(const VarDecl *D) { 2013 std::pair<llvm::Type *, unsigned> &Info = ByRefValueInfo[D]; 2014 if (Info.first) 2015 return Info.first; 2016 2017 QualType Ty = D->getType(); 2018 2019 SmallVector<llvm::Type *, 8> types; 2020 2021 llvm::StructType *ByRefType = 2022 llvm::StructType::create(getLLVMContext(), 2023 "struct.__block_byref_" + D->getNameAsString()); 2024 2025 // void *__isa; 2026 types.push_back(Int8PtrTy); 2027 2028 // void *__forwarding; 2029 types.push_back(llvm::PointerType::getUnqual(ByRefType)); 2030 2031 // int32_t __flags; 2032 types.push_back(Int32Ty); 2033 2034 // int32_t __size; 2035 types.push_back(Int32Ty); 2036 // Note that this must match *exactly* the logic in buildByrefHelpers. 2037 bool HasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D); 2038 if (HasCopyAndDispose) { 2039 /// void *__copy_helper; 2040 types.push_back(Int8PtrTy); 2041 2042 /// void *__destroy_helper; 2043 types.push_back(Int8PtrTy); 2044 } 2045 bool HasByrefExtendedLayout = false; 2046 Qualifiers::ObjCLifetime Lifetime; 2047 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) && 2048 HasByrefExtendedLayout) 2049 /// void *__byref_variable_layout; 2050 types.push_back(Int8PtrTy); 2051 2052 bool Packed = false; 2053 CharUnits Align = getContext().getDeclAlign(D); 2054 if (Align > 2055 getContext().toCharUnitsFromBits(getTarget().getPointerAlign(0))) { 2056 // We have to insert padding. 2057 2058 // The struct above has 2 32-bit integers. 2059 unsigned CurrentOffsetInBytes = 4 * 2; 2060 2061 // And either 2, 3, 4 or 5 pointers. 2062 unsigned noPointers = 2; 2063 if (HasCopyAndDispose) 2064 noPointers += 2; 2065 if (HasByrefExtendedLayout) 2066 noPointers += 1; 2067 2068 CurrentOffsetInBytes += noPointers * CGM.getDataLayout().getTypeAllocSize(Int8PtrTy); 2069 2070 // Align the offset. 2071 unsigned AlignedOffsetInBytes = 2072 llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity()); 2073 2074 unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes; 2075 if (NumPaddingBytes > 0) { 2076 llvm::Type *Ty = Int8Ty; 2077 // FIXME: We need a sema error for alignment larger than the minimum of 2078 // the maximal stack alignment and the alignment of malloc on the system. 2079 if (NumPaddingBytes > 1) 2080 Ty = llvm::ArrayType::get(Ty, NumPaddingBytes); 2081 2082 types.push_back(Ty); 2083 2084 // We want a packed struct. 2085 Packed = true; 2086 } 2087 } 2088 2089 // T x; 2090 types.push_back(ConvertTypeForMem(Ty)); 2091 2092 ByRefType->setBody(types, Packed); 2093 2094 Info.first = ByRefType; 2095 2096 Info.second = types.size() - 1; 2097 2098 return Info.first; 2099} 2100 2101/// Initialize the structural components of a __block variable, i.e. 2102/// everything but the actual object. 2103void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) { 2104 // Find the address of the local. 2105 llvm::Value *addr = emission.Address; 2106 2107 // That's an alloca of the byref structure type. 2108 llvm::StructType *byrefType = cast<llvm::StructType>( 2109 cast<llvm::PointerType>(addr->getType())->getElementType()); 2110 2111 // Build the byref helpers if necessary. This is null if we don't need any. 2112 CodeGenModule::ByrefHelpers *helpers = 2113 buildByrefHelpers(*byrefType, emission); 2114 2115 const VarDecl &D = *emission.Variable; 2116 QualType type = D.getType(); 2117 2118 bool HasByrefExtendedLayout; 2119 Qualifiers::ObjCLifetime ByrefLifetime; 2120 bool ByRefHasLifetime = 2121 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout); 2122 2123 llvm::Value *V; 2124 2125 // Initialize the 'isa', which is just 0 or 1. 2126 int isa = 0; 2127 if (type.isObjCGCWeak()) 2128 isa = 1; 2129 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa"); 2130 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 0, "byref.isa")); 2131 2132 // Store the address of the variable into its own forwarding pointer. 2133 Builder.CreateStore(addr, 2134 Builder.CreateStructGEP(addr, 1, "byref.forwarding")); 2135 2136 // Blocks ABI: 2137 // c) the flags field is set to either 0 if no helper functions are 2138 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are, 2139 BlockFlags flags; 2140 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE; 2141 if (ByRefHasLifetime) { 2142 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED; 2143 else switch (ByrefLifetime) { 2144 case Qualifiers::OCL_Strong: 2145 flags |= BLOCK_BYREF_LAYOUT_STRONG; 2146 break; 2147 case Qualifiers::OCL_Weak: 2148 flags |= BLOCK_BYREF_LAYOUT_WEAK; 2149 break; 2150 case Qualifiers::OCL_ExplicitNone: 2151 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED; 2152 break; 2153 case Qualifiers::OCL_None: 2154 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType()) 2155 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT; 2156 break; 2157 default: 2158 break; 2159 } 2160 if (CGM.getLangOpts().ObjCGCBitmapPrint) { 2161 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask()); 2162 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE) 2163 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE"); 2164 if (flags & BLOCK_BYREF_LAYOUT_MASK) { 2165 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK); 2166 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED) 2167 printf(" BLOCK_BYREF_LAYOUT_EXTENDED"); 2168 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG) 2169 printf(" BLOCK_BYREF_LAYOUT_STRONG"); 2170 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK) 2171 printf(" BLOCK_BYREF_LAYOUT_WEAK"); 2172 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED) 2173 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED"); 2174 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT) 2175 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT"); 2176 } 2177 printf("\n"); 2178 } 2179 } 2180 2181 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 2182 Builder.CreateStructGEP(addr, 2, "byref.flags")); 2183 2184 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType); 2185 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity()); 2186 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 3, "byref.size")); 2187 2188 if (helpers) { 2189 llvm::Value *copy_helper = Builder.CreateStructGEP(addr, 4); 2190 Builder.CreateStore(helpers->CopyHelper, copy_helper); 2191 2192 llvm::Value *destroy_helper = Builder.CreateStructGEP(addr, 5); 2193 Builder.CreateStore(helpers->DisposeHelper, destroy_helper); 2194 } 2195 if (ByRefHasLifetime && HasByrefExtendedLayout) { 2196 llvm::Constant* ByrefLayoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type); 2197 llvm::Value *ByrefInfoAddr = Builder.CreateStructGEP(addr, helpers ? 6 : 4, 2198 "byref.layout"); 2199 // cast destination to pointer to source type. 2200 llvm::Type *DesTy = ByrefLayoutInfo->getType(); 2201 DesTy = DesTy->getPointerTo(); 2202 llvm::Value *BC = Builder.CreatePointerCast(ByrefInfoAddr, DesTy); 2203 Builder.CreateStore(ByrefLayoutInfo, BC); 2204 } 2205} 2206 2207void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) { 2208 llvm::Value *F = CGM.getBlockObjectDispose(); 2209 llvm::Value *args[] = { 2210 Builder.CreateBitCast(V, Int8PtrTy), 2211 llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 2212 }; 2213 EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors? 2214} 2215 2216namespace { 2217 struct CallBlockRelease : EHScopeStack::Cleanup { 2218 llvm::Value *Addr; 2219 CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {} 2220 2221 void Emit(CodeGenFunction &CGF, Flags flags) override { 2222 // Should we be passing FIELD_IS_WEAK here? 2223 CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF); 2224 } 2225 }; 2226} 2227 2228/// Enter a cleanup to destroy a __block variable. Note that this 2229/// cleanup should be a no-op if the variable hasn't left the stack 2230/// yet; if a cleanup is required for the variable itself, that needs 2231/// to be done externally. 2232void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) { 2233 // We don't enter this cleanup if we're in pure-GC mode. 2234 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) 2235 return; 2236 2237 EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address); 2238} 2239 2240/// Adjust the declaration of something from the blocks API. 2241static void configureBlocksRuntimeObject(CodeGenModule &CGM, 2242 llvm::Constant *C) { 2243 if (!CGM.getLangOpts().BlocksRuntimeOptional) return; 2244 2245 auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts()); 2246 if (GV->isDeclaration() && GV->hasExternalLinkage()) 2247 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 2248} 2249 2250llvm::Constant *CodeGenModule::getBlockObjectDispose() { 2251 if (BlockObjectDispose) 2252 return BlockObjectDispose; 2253 2254 llvm::Type *args[] = { Int8PtrTy, Int32Ty }; 2255 llvm::FunctionType *fty 2256 = llvm::FunctionType::get(VoidTy, args, false); 2257 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose"); 2258 configureBlocksRuntimeObject(*this, BlockObjectDispose); 2259 return BlockObjectDispose; 2260} 2261 2262llvm::Constant *CodeGenModule::getBlockObjectAssign() { 2263 if (BlockObjectAssign) 2264 return BlockObjectAssign; 2265 2266 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty }; 2267 llvm::FunctionType *fty 2268 = llvm::FunctionType::get(VoidTy, args, false); 2269 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign"); 2270 configureBlocksRuntimeObject(*this, BlockObjectAssign); 2271 return BlockObjectAssign; 2272} 2273 2274llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { 2275 if (NSConcreteGlobalBlock) 2276 return NSConcreteGlobalBlock; 2277 2278 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock", 2279 Int8PtrTy->getPointerTo(), 2280 nullptr); 2281 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock); 2282 return NSConcreteGlobalBlock; 2283} 2284 2285llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { 2286 if (NSConcreteStackBlock) 2287 return NSConcreteStackBlock; 2288 2289 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock", 2290 Int8PtrTy->getPointerTo(), 2291 nullptr); 2292 configureBlocksRuntimeObject(*this, NSConcreteStackBlock); 2293 return NSConcreteStackBlock; 2294} 2295