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/DataLayout.h" 22 #include "llvm/IR/Module.h" 23 #include "llvm/Support/CallSite.h" 24 #include <algorithm> 25 #include <cstdio> 26 27 using namespace clang; 28 using namespace CodeGen; 29 30 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name) 31 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false), 32 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false), 33 StructureType(0), Block(block), 34 DominatingIP(0) { 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. 43 CodeGenModule::ByrefHelpers::~ByrefHelpers() {} 44 45 /// Build the given block as a global block. 46 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, 47 const CGBlockInfo &blockInfo, 48 llvm::Constant *blockFn); 49 50 /// Build the helper function to copy a block. 51 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM, 52 const CGBlockInfo &blockInfo) { 53 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo); 54 } 55 56 /// Build the helper function to dipose of a block. 57 static 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 /// struct Block_descriptor { 67 /// unsigned long reserved; 68 /// unsigned long size; // size of Block_literal metadata in bytes. 69 /// void *copy_func_helper_decl; // optional copy helper. 70 /// void *destroy_func_decl; // optioanl destructor helper. 71 /// void *block_method_encoding_address;//@encode for block literal signature. 72 /// void *block_layout_info; // encoding of captured block variables. 73 /// }; 74 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM, 75 const CGBlockInfo &blockInfo) { 76 ASTContext &C = CGM.getContext(); 77 78 llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy); 79 llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 80 81 SmallVector<llvm::Constant*, 6> elements; 82 83 // reserved 84 elements.push_back(llvm::ConstantInt::get(ulong, 0)); 85 86 // Size 87 // FIXME: What is the right way to say this doesn't fit? We should give 88 // a user diagnostic in that case. Better fix would be to change the 89 // API to size_t. 90 elements.push_back(llvm::ConstantInt::get(ulong, 91 blockInfo.BlockSize.getQuantity())); 92 93 // Optional copy/dispose helpers. 94 if (blockInfo.NeedsCopyDispose) { 95 // copy_func_helper_decl 96 elements.push_back(buildCopyHelper(CGM, blockInfo)); 97 98 // destroy_func_decl 99 elements.push_back(buildDisposeHelper(CGM, blockInfo)); 100 } 101 102 // Signature. Mandatory ObjC-style method descriptor @encode sequence. 103 std::string typeAtEncoding = 104 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr()); 105 elements.push_back(llvm::ConstantExpr::getBitCast( 106 CGM.GetAddrOfConstantCString(typeAtEncoding), i8p)); 107 108 // GC layout. 109 if (C.getLangOpts().ObjC1) { 110 if (CGM.getLangOpts().getGC() != LangOptions::NonGC) 111 elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo)); 112 else 113 elements.push_back(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo)); 114 } 115 else 116 elements.push_back(llvm::Constant::getNullValue(i8p)); 117 118 llvm::Constant *init = llvm::ConstantStruct::getAnon(elements); 119 120 llvm::GlobalVariable *global = 121 new llvm::GlobalVariable(CGM.getModule(), init->getType(), true, 122 llvm::GlobalValue::InternalLinkage, 123 init, "__block_descriptor_tmp"); 124 125 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType()); 126 } 127 128 /* 129 Purely notional variadic template describing the layout of a block. 130 131 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes> 132 struct Block_literal { 133 /// Initialized to one of: 134 /// extern void *_NSConcreteStackBlock[]; 135 /// extern void *_NSConcreteGlobalBlock[]; 136 /// 137 /// In theory, we could start one off malloc'ed by setting 138 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using 139 /// this isa: 140 /// extern void *_NSConcreteMallocBlock[]; 141 struct objc_class *isa; 142 143 /// These are the flags (with corresponding bit number) that the 144 /// compiler is actually supposed to know about. 145 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block 146 /// descriptor provides copy and dispose helper functions 147 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured 148 /// object with a nontrivial destructor or copy constructor 149 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated 150 /// as global memory 151 /// 29. BLOCK_USE_STRET - indicates that the block function 152 /// uses stret, which objc_msgSend needs to know about 153 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an 154 /// @encoded signature string 155 /// And we're not supposed to manipulate these: 156 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved 157 /// to malloc'ed memory 158 /// 27. BLOCK_IS_GC - indicates that the block has been moved to 159 /// to GC-allocated memory 160 /// Additionally, the bottom 16 bits are a reference count which 161 /// should be zero on the stack. 162 int flags; 163 164 /// Reserved; should be zero-initialized. 165 int reserved; 166 167 /// Function pointer generated from block literal. 168 _ResultType (*invoke)(Block_literal *, _ParamTypes...); 169 170 /// Block description metadata generated from block literal. 171 struct Block_descriptor *block_descriptor; 172 173 /// Captured values follow. 174 _CapturesTypes captures...; 175 }; 176 */ 177 178 /// The number of fields in a block header. 179 const unsigned BlockHeaderSize = 5; 180 181 namespace { 182 /// A chunk of data that we actually have to capture in the block. 183 struct BlockLayoutChunk { 184 CharUnits Alignment; 185 CharUnits Size; 186 Qualifiers::ObjCLifetime Lifetime; 187 const BlockDecl::Capture *Capture; // null for 'this' 188 llvm::Type *Type; 189 190 BlockLayoutChunk(CharUnits align, CharUnits size, 191 Qualifiers::ObjCLifetime lifetime, 192 const BlockDecl::Capture *capture, 193 llvm::Type *type) 194 : Alignment(align), Size(size), Lifetime(lifetime), 195 Capture(capture), Type(type) {} 196 197 /// Tell the block info that this chunk has the given field index. 198 void setIndex(CGBlockInfo &info, unsigned index) { 199 if (!Capture) 200 info.CXXThisIndex = index; 201 else 202 info.Captures[Capture->getVariable()] 203 = CGBlockInfo::Capture::makeIndex(index); 204 } 205 }; 206 207 /// Order by 1) all __strong together 2) next, all byfref together 3) next, 208 /// all __weak together. Preserve descending alignment in all situations. 209 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) { 210 CharUnits LeftValue, RightValue; 211 bool LeftByref = left.Capture ? left.Capture->isByRef() : false; 212 bool RightByref = right.Capture ? right.Capture->isByRef() : false; 213 214 if (left.Lifetime == Qualifiers::OCL_Strong && 215 left.Alignment >= right.Alignment) 216 LeftValue = CharUnits::fromQuantity(64); 217 else if (LeftByref && left.Alignment >= right.Alignment) 218 LeftValue = CharUnits::fromQuantity(32); 219 else if (left.Lifetime == Qualifiers::OCL_Weak && 220 left.Alignment >= right.Alignment) 221 LeftValue = CharUnits::fromQuantity(16); 222 else 223 LeftValue = left.Alignment; 224 if (right.Lifetime == Qualifiers::OCL_Strong && 225 right.Alignment >= left.Alignment) 226 RightValue = CharUnits::fromQuantity(64); 227 else if (RightByref && right.Alignment >= left.Alignment) 228 RightValue = CharUnits::fromQuantity(32); 229 else if (right.Lifetime == Qualifiers::OCL_Weak && 230 right.Alignment >= left.Alignment) 231 RightValue = CharUnits::fromQuantity(16); 232 else 233 RightValue = right.Alignment; 234 235 return LeftValue > RightValue; 236 } 237 } 238 239 /// Determines if the given type is safe for constant capture in C++. 240 static bool isSafeForCXXConstantCapture(QualType type) { 241 const RecordType *recordType = 242 type->getBaseElementTypeUnsafe()->getAs<RecordType>(); 243 244 // Only records can be unsafe. 245 if (!recordType) return true; 246 247 const CXXRecordDecl *record = cast<CXXRecordDecl>(recordType->getDecl()); 248 249 // Maintain semantics for classes with non-trivial dtors or copy ctors. 250 if (!record->hasTrivialDestructor()) return false; 251 if (record->hasNonTrivialCopyConstructor()) return false; 252 253 // Otherwise, we just have to make sure there aren't any mutable 254 // fields that might have changed since initialization. 255 return !record->hasMutableFields(); 256 } 257 258 /// It is illegal to modify a const object after initialization. 259 /// Therefore, if a const object has a constant initializer, we don't 260 /// actually need to keep storage for it in the block; we'll just 261 /// rematerialize it at the start of the block function. This is 262 /// acceptable because we make no promises about address stability of 263 /// captured variables. 264 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM, 265 CodeGenFunction *CGF, 266 const VarDecl *var) { 267 QualType type = var->getType(); 268 269 // We can only do this if the variable is const. 270 if (!type.isConstQualified()) return 0; 271 272 // Furthermore, in C++ we have to worry about mutable fields: 273 // C++ [dcl.type.cv]p4: 274 // Except that any class member declared mutable can be 275 // modified, any attempt to modify a const object during its 276 // lifetime results in undefined behavior. 277 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type)) 278 return 0; 279 280 // If the variable doesn't have any initializer (shouldn't this be 281 // invalid?), it's not clear what we should do. Maybe capture as 282 // zero? 283 const Expr *init = var->getInit(); 284 if (!init) return 0; 285 286 return CGM.EmitConstantInit(*var, CGF); 287 } 288 289 /// Get the low bit of a nonzero character count. This is the 290 /// alignment of the nth byte if the 0th byte is universally aligned. 291 static CharUnits getLowBit(CharUnits v) { 292 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1)); 293 } 294 295 static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, 296 SmallVectorImpl<llvm::Type*> &elementTypes) { 297 ASTContext &C = CGM.getContext(); 298 299 // The header is basically a 'struct { void *; int; int; void *; void *; }'. 300 CharUnits ptrSize, ptrAlign, intSize, intAlign; 301 llvm::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.VoidPtrTy); 302 llvm::tie(intSize, intAlign) = C.getTypeInfoInChars(C.IntTy); 303 304 // Are there crazy embedded platforms where this isn't true? 305 assert(intSize <= ptrSize && "layout assumptions horribly violated"); 306 307 CharUnits headerSize = ptrSize; 308 if (2 * intSize < ptrAlign) headerSize += ptrSize; 309 else headerSize += 2 * intSize; 310 headerSize += 2 * ptrSize; 311 312 info.BlockAlign = ptrAlign; 313 info.BlockSize = headerSize; 314 315 assert(elementTypes.empty()); 316 llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 317 llvm::Type *intTy = CGM.getTypes().ConvertType(C.IntTy); 318 elementTypes.push_back(i8p); 319 elementTypes.push_back(intTy); 320 elementTypes.push_back(intTy); 321 elementTypes.push_back(i8p); 322 elementTypes.push_back(CGM.getBlockDescriptorType()); 323 324 assert(elementTypes.size() == BlockHeaderSize); 325 } 326 327 /// Compute the layout of the given block. Attempts to lay the block 328 /// out with minimal space requirements. 329 static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, 330 CGBlockInfo &info) { 331 ASTContext &C = CGM.getContext(); 332 const BlockDecl *block = info.getBlockDecl(); 333 334 SmallVector<llvm::Type*, 8> elementTypes; 335 initializeForBlockHeader(CGM, info, elementTypes); 336 337 if (!block->hasCaptures()) { 338 info.StructureType = 339 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 340 info.CanBeGlobal = true; 341 return; 342 } 343 else if (C.getLangOpts().ObjC1 && 344 CGM.getLangOpts().getGC() == LangOptions::NonGC) 345 info.HasCapturedVariableLayout = true; 346 347 // Collect the layout chunks. 348 SmallVector<BlockLayoutChunk, 16> layout; 349 layout.reserve(block->capturesCXXThis() + 350 (block->capture_end() - block->capture_begin())); 351 352 CharUnits maxFieldAlign; 353 354 // First, 'this'. 355 if (block->capturesCXXThis()) { 356 const DeclContext *DC = block->getDeclContext(); 357 for (; isa<BlockDecl>(DC); DC = cast<BlockDecl>(DC)->getDeclContext()) 358 ; 359 QualType thisType; 360 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 361 thisType = C.getPointerType(C.getRecordType(RD)); 362 else 363 thisType = cast<CXXMethodDecl>(DC)->getThisType(C); 364 365 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType); 366 std::pair<CharUnits,CharUnits> tinfo 367 = CGM.getContext().getTypeInfoInChars(thisType); 368 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 369 370 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 371 Qualifiers::OCL_None, 372 0, llvmType)); 373 } 374 375 // Next, all the block captures. 376 for (BlockDecl::capture_const_iterator ci = block->capture_begin(), 377 ce = block->capture_end(); ci != ce; ++ci) { 378 const VarDecl *variable = ci->getVariable(); 379 380 if (ci->isByRef()) { 381 // We have to copy/dispose of the __block reference. 382 info.NeedsCopyDispose = true; 383 384 // Just use void* instead of a pointer to the byref type. 385 QualType byRefPtrTy = C.VoidPtrTy; 386 387 llvm::Type *llvmType = CGM.getTypes().ConvertType(byRefPtrTy); 388 std::pair<CharUnits,CharUnits> tinfo 389 = CGM.getContext().getTypeInfoInChars(byRefPtrTy); 390 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 391 392 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 393 Qualifiers::OCL_None, 394 &*ci, llvmType)); 395 continue; 396 } 397 398 // Otherwise, build a layout chunk with the size and alignment of 399 // the declaration. 400 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) { 401 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant); 402 continue; 403 } 404 405 // If we have a lifetime qualifier, honor it for capture purposes. 406 // That includes *not* copying it if it's __unsafe_unretained. 407 Qualifiers::ObjCLifetime lifetime = 408 variable->getType().getObjCLifetime(); 409 if (lifetime) { 410 switch (lifetime) { 411 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 412 case Qualifiers::OCL_ExplicitNone: 413 case Qualifiers::OCL_Autoreleasing: 414 break; 415 416 case Qualifiers::OCL_Strong: 417 case Qualifiers::OCL_Weak: 418 info.NeedsCopyDispose = true; 419 } 420 421 // Block pointers require copy/dispose. So do Objective-C pointers. 422 } else if (variable->getType()->isObjCRetainableType()) { 423 info.NeedsCopyDispose = true; 424 // used for mrr below. 425 lifetime = Qualifiers::OCL_Strong; 426 427 // So do types that require non-trivial copy construction. 428 } else if (ci->hasCopyExpr()) { 429 info.NeedsCopyDispose = true; 430 info.HasCXXObject = true; 431 432 // And so do types with destructors. 433 } else if (CGM.getLangOpts().CPlusPlus) { 434 if (const CXXRecordDecl *record = 435 variable->getType()->getAsCXXRecordDecl()) { 436 if (!record->hasTrivialDestructor()) { 437 info.HasCXXObject = true; 438 info.NeedsCopyDispose = true; 439 } 440 } 441 } 442 443 QualType VT = variable->getType(); 444 CharUnits size = C.getTypeSizeInChars(VT); 445 CharUnits align = C.getDeclAlign(variable); 446 447 maxFieldAlign = std::max(maxFieldAlign, align); 448 449 llvm::Type *llvmType = 450 CGM.getTypes().ConvertTypeForMem(VT); 451 452 layout.push_back(BlockLayoutChunk(align, size, lifetime, &*ci, llvmType)); 453 } 454 455 // If that was everything, we're done here. 456 if (layout.empty()) { 457 info.StructureType = 458 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 459 info.CanBeGlobal = true; 460 return; 461 } 462 463 // Sort the layout by alignment. We have to use a stable sort here 464 // to get reproducible results. There should probably be an 465 // llvm::array_pod_stable_sort. 466 std::stable_sort(layout.begin(), layout.end()); 467 468 // Needed for blocks layout info. 469 info.BlockHeaderForcedGapOffset = info.BlockSize; 470 info.BlockHeaderForcedGapSize = CharUnits::Zero(); 471 472 CharUnits &blockSize = info.BlockSize; 473 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign); 474 475 // Assuming that the first byte in the header is maximally aligned, 476 // get the alignment of the first byte following the header. 477 CharUnits endAlign = getLowBit(blockSize); 478 479 // If the end of the header isn't satisfactorily aligned for the 480 // maximum thing, look for things that are okay with the header-end 481 // alignment, and keep appending them until we get something that's 482 // aligned right. This algorithm is only guaranteed optimal if 483 // that condition is satisfied at some point; otherwise we can get 484 // things like: 485 // header // next byte has alignment 4 486 // something_with_size_5; // next byte has alignment 1 487 // something_with_alignment_8; 488 // which has 7 bytes of padding, as opposed to the naive solution 489 // which might have less (?). 490 if (endAlign < maxFieldAlign) { 491 SmallVectorImpl<BlockLayoutChunk>::iterator 492 li = layout.begin() + 1, le = layout.end(); 493 494 // Look for something that the header end is already 495 // satisfactorily aligned for. 496 for (; li != le && endAlign < li->Alignment; ++li) 497 ; 498 499 // If we found something that's naturally aligned for the end of 500 // the header, keep adding things... 501 if (li != le) { 502 SmallVectorImpl<BlockLayoutChunk>::iterator first = li; 503 for (; li != le; ++li) { 504 assert(endAlign >= li->Alignment); 505 506 li->setIndex(info, elementTypes.size()); 507 elementTypes.push_back(li->Type); 508 blockSize += li->Size; 509 endAlign = getLowBit(blockSize); 510 511 // ...until we get to the alignment of the maximum field. 512 if (endAlign >= maxFieldAlign) { 513 if (li == first) { 514 // No user field was appended. So, a gap was added. 515 // Save total gap size for use in block layout bit map. 516 info.BlockHeaderForcedGapSize = li->Size; 517 } 518 break; 519 } 520 } 521 // Don't re-append everything we just appended. 522 layout.erase(first, li); 523 } 524 } 525 526 assert(endAlign == getLowBit(blockSize)); 527 528 // At this point, we just have to add padding if the end align still 529 // isn't aligned right. 530 if (endAlign < maxFieldAlign) { 531 CharUnits newBlockSize = blockSize.RoundUpToAlignment(maxFieldAlign); 532 CharUnits padding = newBlockSize - blockSize; 533 534 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty, 535 padding.getQuantity())); 536 blockSize = newBlockSize; 537 endAlign = getLowBit(blockSize); // might be > maxFieldAlign 538 } 539 540 assert(endAlign >= maxFieldAlign); 541 assert(endAlign == getLowBit(blockSize)); 542 // Slam everything else on now. This works because they have 543 // strictly decreasing alignment and we expect that size is always a 544 // multiple of alignment. 545 for (SmallVectorImpl<BlockLayoutChunk>::iterator 546 li = layout.begin(), le = layout.end(); li != le; ++li) { 547 assert(endAlign >= li->Alignment); 548 li->setIndex(info, elementTypes.size()); 549 elementTypes.push_back(li->Type); 550 blockSize += li->Size; 551 endAlign = getLowBit(blockSize); 552 } 553 554 info.StructureType = 555 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 556 } 557 558 /// Enter the scope of a block. This should be run at the entrance to 559 /// a full-expression so that the block's cleanups are pushed at the 560 /// right place in the stack. 561 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) { 562 assert(CGF.HaveInsertPoint()); 563 564 // Allocate the block info and place it at the head of the list. 565 CGBlockInfo &blockInfo = 566 *new CGBlockInfo(block, CGF.CurFn->getName()); 567 blockInfo.NextBlockInfo = CGF.FirstBlockInfo; 568 CGF.FirstBlockInfo = &blockInfo; 569 570 // Compute information about the layout, etc., of this block, 571 // pushing cleanups as necessary. 572 computeBlockInfo(CGF.CGM, &CGF, blockInfo); 573 574 // Nothing else to do if it can be global. 575 if (blockInfo.CanBeGlobal) return; 576 577 // Make the allocation for the block. 578 blockInfo.Address = 579 CGF.CreateTempAlloca(blockInfo.StructureType, "block"); 580 blockInfo.Address->setAlignment(blockInfo.BlockAlign.getQuantity()); 581 582 // If there are cleanups to emit, enter them (but inactive). 583 if (!blockInfo.NeedsCopyDispose) return; 584 585 // Walk through the captures (in order) and find the ones not 586 // captured by constant. 587 for (BlockDecl::capture_const_iterator ci = block->capture_begin(), 588 ce = block->capture_end(); ci != ce; ++ci) { 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*. 637 void 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. 647 static 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. 664 void 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 != 0); 671 } 672 673 /// Emit a block literal expression in the current function. 674 llvm::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 OwningPtr<CGBlockInfo> blockInfo; 686 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo, 687 blockExpr->getBlockDecl())); 688 689 blockInfo->BlockExpression = blockExpr; 690 return EmitBlockLiteral(*blockInfo); 691 } 692 693 llvm::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 CurFuncDecl, 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 (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 748 ce = blockDecl->capture_end(); ci != ce; ++ci) { 749 const VarDecl *variable = ci->getVariable(); 750 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 751 752 // Ignore constant captures. 753 if (capture.isConstant()) continue; 754 755 QualType type = variable->getType(); 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 = 0; 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.CreateLoad(src, "byref.capture"); 800 else 801 src = Builder.CreateBitCast(src, VoidPtrTy); 802 803 // Write that void* into the capture field. 804 Builder.CreateStore(src, blockField); 805 806 // If we have a copy constructor, evaluate that into the block field. 807 } else if (const Expr *copyExpr = ci->getCopyExpr()) { 808 if (blockDecl->isConversionFromLambda()) { 809 // If we have a lambda conversion, emit the expression 810 // directly into the block instead. 811 CharUnits Align = getContext().getTypeAlignInChars(type); 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 Builder.CreateStore(Builder.CreateLoad(src, "ref.val"), blockField); 825 826 // Otherwise, fake up a POD copy into the block field. 827 } else { 828 // Fake up a new variable so that EmitScalarInit doesn't think 829 // we're referring to the variable in its own initializer. 830 ImplicitParamDecl blockFieldPseudoVar(/*DC*/ 0, SourceLocation(), 831 /*name*/ 0, type); 832 833 // We use one of these or the other depending on whether the 834 // reference is nested. 835 DeclRefExpr declRef(const_cast<VarDecl*>(variable), 836 /*refersToEnclosing*/ ci->isNested(), type, 837 VK_LValue, SourceLocation()); 838 839 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue, 840 &declRef, VK_RValue); 841 EmitExprAsInit(&l2r, &blockFieldPseudoVar, 842 MakeAddrLValue(blockField, type, 843 getContext().getDeclAlign(variable)), 844 /*captured by init*/ false); 845 } 846 847 // Activate the cleanup if layout pushed one. 848 if (!ci->isByRef()) { 849 EHScopeStack::stable_iterator cleanup = capture.getCleanup(); 850 if (cleanup.isValid()) 851 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP); 852 } 853 } 854 855 // Cast to the converted block-pointer type, which happens (somewhat 856 // unfortunately) to be a pointer to function type. 857 llvm::Value *result = 858 Builder.CreateBitCast(blockAddr, 859 ConvertType(blockInfo.getBlockExpr()->getType())); 860 861 return result; 862 } 863 864 865 llvm::Type *CodeGenModule::getBlockDescriptorType() { 866 if (BlockDescriptorType) 867 return BlockDescriptorType; 868 869 llvm::Type *UnsignedLongTy = 870 getTypes().ConvertType(getContext().UnsignedLongTy); 871 872 // struct __block_descriptor { 873 // unsigned long reserved; 874 // unsigned long block_size; 875 // 876 // // later, the following will be added 877 // 878 // struct { 879 // void (*copyHelper)(); 880 // void (*copyHelper)(); 881 // } helpers; // !!! optional 882 // 883 // const char *signature; // the block signature 884 // const char *layout; // reserved 885 // }; 886 BlockDescriptorType = 887 llvm::StructType::create("struct.__block_descriptor", 888 UnsignedLongTy, UnsignedLongTy, NULL); 889 890 // Now form a pointer to that. 891 BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType); 892 return BlockDescriptorType; 893 } 894 895 llvm::Type *CodeGenModule::getGenericBlockLiteralType() { 896 if (GenericBlockLiteralType) 897 return GenericBlockLiteralType; 898 899 llvm::Type *BlockDescPtrTy = getBlockDescriptorType(); 900 901 // struct __block_literal_generic { 902 // void *__isa; 903 // int __flags; 904 // int __reserved; 905 // void (*__invoke)(void *); 906 // struct __block_descriptor *__descriptor; 907 // }; 908 GenericBlockLiteralType = 909 llvm::StructType::create("struct.__block_literal_generic", 910 VoidPtrTy, IntTy, IntTy, VoidPtrTy, 911 BlockDescPtrTy, NULL); 912 913 return GenericBlockLiteralType; 914 } 915 916 917 RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr* E, 918 ReturnValueSlot ReturnValue) { 919 const BlockPointerType *BPT = 920 E->getCallee()->getType()->getAs<BlockPointerType>(); 921 922 llvm::Value *Callee = EmitScalarExpr(E->getCallee()); 923 924 // Get a pointer to the generic block literal. 925 llvm::Type *BlockLiteralTy = 926 llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType()); 927 928 // Bitcast the callee to a block literal. 929 llvm::Value *BlockLiteral = 930 Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal"); 931 932 // Get the function pointer from the literal. 933 llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3); 934 935 BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy); 936 937 // Add the block literal. 938 CallArgList Args; 939 Args.add(RValue::get(BlockLiteral), getContext().VoidPtrTy); 940 941 QualType FnType = BPT->getPointeeType(); 942 943 // And the rest of the arguments. 944 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), 945 E->arg_begin(), E->arg_end()); 946 947 // Load the function. 948 llvm::Value *Func = Builder.CreateLoad(FuncPtr); 949 950 const FunctionType *FuncTy = FnType->castAs<FunctionType>(); 951 const CGFunctionInfo &FnInfo = 952 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy); 953 954 // Cast the function pointer to the right type. 955 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo); 956 957 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy); 958 Func = Builder.CreateBitCast(Func, BlockFTyPtr); 959 960 // And call the block. 961 return EmitCall(FnInfo, Func, ReturnValue, Args); 962 } 963 964 llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable, 965 bool isByRef) { 966 assert(BlockInfo && "evaluating block ref without block information?"); 967 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable); 968 969 // Handle constant captures. 970 if (capture.isConstant()) return LocalDeclMap[variable]; 971 972 llvm::Value *addr = 973 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(), 974 "block.capture.addr"); 975 976 if (isByRef) { 977 // addr should be a void** right now. Load, then cast the result 978 // to byref*. 979 980 addr = Builder.CreateLoad(addr); 981 llvm::PointerType *byrefPointerType 982 = llvm::PointerType::get(BuildByRefType(variable), 0); 983 addr = Builder.CreateBitCast(addr, byrefPointerType, 984 "byref.addr"); 985 986 // Follow the forwarding pointer. 987 addr = Builder.CreateStructGEP(addr, 1, "byref.forwarding"); 988 addr = Builder.CreateLoad(addr, "byref.addr.forwarded"); 989 990 // Cast back to byref* and GEP over to the actual object. 991 addr = Builder.CreateBitCast(addr, byrefPointerType); 992 addr = Builder.CreateStructGEP(addr, getByRefValueLLVMField(variable), 993 variable->getNameAsString()); 994 } 995 996 if (variable->getType()->isReferenceType()) 997 addr = Builder.CreateLoad(addr, "ref.tmp"); 998 999 return addr; 1000 } 1001 1002 llvm::Constant * 1003 CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *blockExpr, 1004 const char *name) { 1005 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), name); 1006 blockInfo.BlockExpression = blockExpr; 1007 1008 // Compute information about the layout, etc., of this block. 1009 computeBlockInfo(*this, 0, blockInfo); 1010 1011 // Using that metadata, generate the actual block function. 1012 llvm::Constant *blockFn; 1013 { 1014 llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap; 1015 blockFn = CodeGenFunction(*this).GenerateBlockFunction(GlobalDecl(), 1016 blockInfo, 1017 0, LocalDeclMap, 1018 false); 1019 } 1020 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); 1021 1022 return buildGlobalBlock(*this, blockInfo, blockFn); 1023 } 1024 1025 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, 1026 const CGBlockInfo &blockInfo, 1027 llvm::Constant *blockFn) { 1028 assert(blockInfo.CanBeGlobal); 1029 1030 // Generate the constants for the block literal initializer. 1031 llvm::Constant *fields[BlockHeaderSize]; 1032 1033 // isa 1034 fields[0] = CGM.getNSConcreteGlobalBlock(); 1035 1036 // __flags 1037 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE; 1038 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; 1039 1040 fields[1] = llvm::ConstantInt::get(CGM.IntTy, flags.getBitMask()); 1041 1042 // Reserved 1043 fields[2] = llvm::Constant::getNullValue(CGM.IntTy); 1044 1045 // Function 1046 fields[3] = blockFn; 1047 1048 // Descriptor 1049 fields[4] = buildBlockDescriptor(CGM, blockInfo); 1050 1051 llvm::Constant *init = llvm::ConstantStruct::getAnon(fields); 1052 1053 llvm::GlobalVariable *literal = 1054 new llvm::GlobalVariable(CGM.getModule(), 1055 init->getType(), 1056 /*constant*/ true, 1057 llvm::GlobalVariable::InternalLinkage, 1058 init, 1059 "__block_literal_global"); 1060 literal->setAlignment(blockInfo.BlockAlign.getQuantity()); 1061 1062 // Return a constant of the appropriately-casted type. 1063 llvm::Type *requiredType = 1064 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType()); 1065 return llvm::ConstantExpr::getBitCast(literal, requiredType); 1066 } 1067 1068 llvm::Function * 1069 CodeGenFunction::GenerateBlockFunction(GlobalDecl GD, 1070 const CGBlockInfo &blockInfo, 1071 const Decl *outerFnDecl, 1072 const DeclMapTy &ldm, 1073 bool IsLambdaConversionToBlock) { 1074 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1075 1076 // Check if we should generate debug info for this block function. 1077 maybeInitializeDebugInfo(); 1078 CurGD = GD; 1079 1080 BlockInfo = &blockInfo; 1081 1082 // Arrange for local static and local extern declarations to appear 1083 // to be local to this function as well, in case they're directly 1084 // referenced in a block. 1085 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) { 1086 const VarDecl *var = dyn_cast<VarDecl>(i->first); 1087 if (var && !var->hasLocalStorage()) 1088 LocalDeclMap[var] = i->second; 1089 } 1090 1091 // Begin building the function declaration. 1092 1093 // Build the argument list. 1094 FunctionArgList args; 1095 1096 // The first argument is the block pointer. Just take it as a void* 1097 // and cast it later. 1098 QualType selfTy = getContext().VoidPtrTy; 1099 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor"); 1100 1101 ImplicitParamDecl selfDecl(const_cast<BlockDecl*>(blockDecl), 1102 SourceLocation(), II, selfTy); 1103 args.push_back(&selfDecl); 1104 1105 // Now add the rest of the parameters. 1106 for (BlockDecl::param_const_iterator i = blockDecl->param_begin(), 1107 e = blockDecl->param_end(); i != e; ++i) 1108 args.push_back(*i); 1109 1110 // Create the function declaration. 1111 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType(); 1112 const CGFunctionInfo &fnInfo = 1113 CGM.getTypes().arrangeFunctionDeclaration(fnType->getResultType(), args, 1114 fnType->getExtInfo(), 1115 fnType->isVariadic()); 1116 if (CGM.ReturnTypeUsesSRet(fnInfo)) 1117 blockInfo.UsesStret = true; 1118 1119 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo); 1120 1121 MangleBuffer name; 1122 CGM.getBlockMangledName(GD, name, blockDecl); 1123 llvm::Function *fn = 1124 llvm::Function::Create(fnLLVMType, llvm::GlobalValue::InternalLinkage, 1125 name.getString(), &CGM.getModule()); 1126 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo); 1127 1128 // Begin generating the function. 1129 StartFunction(blockDecl, fnType->getResultType(), fn, fnInfo, args, 1130 blockInfo.getBlockExpr()->getBody()->getLocStart()); 1131 CurFuncDecl = outerFnDecl; // StartFunction sets this to blockDecl 1132 1133 // Okay. Undo some of what StartFunction did. 1134 1135 // Pull the 'self' reference out of the local decl map. 1136 llvm::Value *blockAddr = LocalDeclMap[&selfDecl]; 1137 LocalDeclMap.erase(&selfDecl); 1138 BlockPointer = Builder.CreateBitCast(blockAddr, 1139 blockInfo.StructureType->getPointerTo(), 1140 "block"); 1141 1142 // If we have a C++ 'this' reference, go ahead and force it into 1143 // existence now. 1144 if (blockDecl->capturesCXXThis()) { 1145 llvm::Value *addr = Builder.CreateStructGEP(BlockPointer, 1146 blockInfo.CXXThisIndex, 1147 "block.captured-this"); 1148 CXXThisValue = Builder.CreateLoad(addr, "this"); 1149 } 1150 1151 // LoadObjCSelf() expects there to be an entry for 'self' in LocalDeclMap; 1152 // appease it. 1153 if (const ObjCMethodDecl *method 1154 = dyn_cast_or_null<ObjCMethodDecl>(CurFuncDecl)) { 1155 const VarDecl *self = method->getSelfDecl(); 1156 1157 // There might not be a capture for 'self', but if there is... 1158 if (blockInfo.Captures.count(self)) { 1159 const CGBlockInfo::Capture &capture = blockInfo.getCapture(self); 1160 1161 llvm::Value *selfAddr = Builder.CreateStructGEP(BlockPointer, 1162 capture.getIndex(), 1163 "block.captured-self"); 1164 1165 // At -O0 we generate an explicit alloca for self to facilitate debugging. 1166 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1167 llvm::Value *load = Builder.CreateLoad(selfAddr); 1168 1169 // Allocate a stack slot for it, so we can generate debug info for it 1170 llvm::AllocaInst *alloca = CreateTempAlloca(load->getType(), 1171 "block.captured-self.addr"); 1172 unsigned align = getContext().getDeclAlign(self).getQuantity(); 1173 alloca->setAlignment(align); 1174 Builder.CreateAlignedStore(load, alloca, align); 1175 LocalDeclMap[self] = alloca; 1176 } else 1177 LocalDeclMap[self] = selfAddr; 1178 } 1179 } 1180 1181 // Also force all the constant captures. 1182 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1183 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1184 const VarDecl *variable = ci->getVariable(); 1185 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1186 if (!capture.isConstant()) continue; 1187 1188 unsigned align = getContext().getDeclAlign(variable).getQuantity(); 1189 1190 llvm::AllocaInst *alloca = 1191 CreateMemTemp(variable->getType(), "block.captured-const"); 1192 alloca->setAlignment(align); 1193 1194 Builder.CreateAlignedStore(capture.getConstant(), alloca, align); 1195 1196 LocalDeclMap[variable] = alloca; 1197 } 1198 1199 // Save a spot to insert the debug information for all the DeclRefExprs. 1200 llvm::BasicBlock *entry = Builder.GetInsertBlock(); 1201 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); 1202 --entry_ptr; 1203 1204 if (IsLambdaConversionToBlock) 1205 EmitLambdaBlockInvokeBody(); 1206 else 1207 EmitStmt(blockDecl->getBody()); 1208 1209 // Remember where we were... 1210 llvm::BasicBlock *resume = Builder.GetInsertBlock(); 1211 1212 // Go back to the entry. 1213 ++entry_ptr; 1214 Builder.SetInsertPoint(entry, entry_ptr); 1215 1216 // Emit debug information for all the DeclRefExprs. 1217 // FIXME: also for 'this' 1218 if (CGDebugInfo *DI = getDebugInfo()) { 1219 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1220 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1221 const VarDecl *variable = ci->getVariable(); 1222 DI->EmitLocation(Builder, variable->getLocation()); 1223 1224 if (CGM.getCodeGenOpts().getDebugInfo() 1225 >= CodeGenOptions::LimitedDebugInfo) { 1226 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1227 if (capture.isConstant()) { 1228 DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], 1229 Builder); 1230 continue; 1231 } 1232 1233 DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointer, 1234 Builder, blockInfo); 1235 } 1236 } 1237 // Recover location if it was changed in the above loop. 1238 DI->EmitLocation(Builder, 1239 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1240 } 1241 1242 // And resume where we left off. 1243 if (resume == 0) 1244 Builder.ClearInsertionPoint(); 1245 else 1246 Builder.SetInsertPoint(resume); 1247 1248 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1249 1250 return fn; 1251 } 1252 1253 /* 1254 notes.push_back(HelperInfo()); 1255 HelperInfo ¬e = notes.back(); 1256 note.index = capture.getIndex(); 1257 note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type)); 1258 note.cxxbar_import = ci->getCopyExpr(); 1259 1260 if (ci->isByRef()) { 1261 note.flag = BLOCK_FIELD_IS_BYREF; 1262 if (type.isObjCGCWeak()) 1263 note.flag |= BLOCK_FIELD_IS_WEAK; 1264 } else if (type->isBlockPointerType()) { 1265 note.flag = BLOCK_FIELD_IS_BLOCK; 1266 } else { 1267 note.flag = BLOCK_FIELD_IS_OBJECT; 1268 } 1269 */ 1270 1271 1272 /// Generate the copy-helper function for a block closure object: 1273 /// static void block_copy_helper(block_t *dst, block_t *src); 1274 /// The runtime will have previously initialized 'dst' by doing a 1275 /// bit-copy of 'src'. 1276 /// 1277 /// Note that this copies an entire block closure object to the heap; 1278 /// it should not be confused with a 'byref copy helper', which moves 1279 /// the contents of an individual __block variable to the heap. 1280 llvm::Constant * 1281 CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) { 1282 ASTContext &C = getContext(); 1283 1284 FunctionArgList args; 1285 ImplicitParamDecl dstDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1286 args.push_back(&dstDecl); 1287 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1288 args.push_back(&srcDecl); 1289 1290 const CGFunctionInfo &FI = 1291 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1292 FunctionType::ExtInfo(), 1293 /*variadic*/ false); 1294 1295 // FIXME: it would be nice if these were mergeable with things with 1296 // identical semantics. 1297 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1298 1299 llvm::Function *Fn = 1300 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1301 "__copy_helper_block_", &CGM.getModule()); 1302 1303 IdentifierInfo *II 1304 = &CGM.getContext().Idents.get("__copy_helper_block_"); 1305 1306 // Check if we should generate debug info for this block helper function. 1307 maybeInitializeDebugInfo(); 1308 1309 FunctionDecl *FD = FunctionDecl::Create(C, 1310 C.getTranslationUnitDecl(), 1311 SourceLocation(), 1312 SourceLocation(), II, C.VoidTy, 0, 1313 SC_Static, 1314 SC_None, 1315 false, 1316 false); 1317 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1318 1319 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1320 1321 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1322 src = Builder.CreateLoad(src); 1323 src = Builder.CreateBitCast(src, structPtrTy, "block.source"); 1324 1325 llvm::Value *dst = GetAddrOfLocalVar(&dstDecl); 1326 dst = Builder.CreateLoad(dst); 1327 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest"); 1328 1329 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1330 1331 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1332 ce = blockDecl->capture_end(); ci != ce; ++ci) { 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 llvm::PointerType *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. 1458 llvm::Constant * 1459 CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { 1460 ASTContext &C = getContext(); 1461 1462 FunctionArgList args; 1463 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1464 args.push_back(&srcDecl); 1465 1466 const CGFunctionInfo &FI = 1467 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1468 FunctionType::ExtInfo(), 1469 /*variadic*/ false); 1470 1471 // FIXME: We'd like to put these into a mergable by content, with 1472 // internal linkage. 1473 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1474 1475 llvm::Function *Fn = 1476 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1477 "__destroy_helper_block_", &CGM.getModule()); 1478 1479 // Check if we should generate debug info for this block destroy function. 1480 maybeInitializeDebugInfo(); 1481 1482 IdentifierInfo *II 1483 = &CGM.getContext().Idents.get("__destroy_helper_block_"); 1484 1485 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), 1486 SourceLocation(), 1487 SourceLocation(), II, C.VoidTy, 0, 1488 SC_Static, 1489 SC_None, 1490 false, false); 1491 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1492 1493 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1494 1495 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1496 src = Builder.CreateLoad(src); 1497 src = Builder.CreateBitCast(src, structPtrTy, "block"); 1498 1499 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1500 1501 CodeGenFunction::RunCleanupsScope cleanups(*this); 1502 1503 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1504 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1505 const VarDecl *variable = ci->getVariable(); 1506 QualType type = variable->getType(); 1507 1508 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1509 if (capture.isConstant()) continue; 1510 1511 BlockFieldFlags flags; 1512 const CXXDestructorDecl *dtor = 0; 1513 1514 bool useARCWeakDestroy = false; 1515 bool useARCStrongDestroy = false; 1516 1517 if (ci->isByRef()) { 1518 flags = BLOCK_FIELD_IS_BYREF; 1519 if (type.isObjCGCWeak()) 1520 flags |= BLOCK_FIELD_IS_WEAK; 1521 } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1522 if (record->hasTrivialDestructor()) 1523 continue; 1524 dtor = record->getDestructor(); 1525 } else if (type->isObjCRetainableType()) { 1526 flags = BLOCK_FIELD_IS_OBJECT; 1527 if (type->isBlockPointerType()) 1528 flags = BLOCK_FIELD_IS_BLOCK; 1529 1530 // Special rules for ARC captures. 1531 if (getLangOpts().ObjCAutoRefCount) { 1532 Qualifiers qs = type.getQualifiers(); 1533 1534 // Don't generate special dispose logic for a captured object 1535 // unless it's __strong or __weak. 1536 if (!qs.hasStrongOrWeakObjCLifetime()) 1537 continue; 1538 1539 // Support __weak direct captures. 1540 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) 1541 useARCWeakDestroy = true; 1542 1543 // Tools really want us to use objc_storeStrong here. 1544 else 1545 useARCStrongDestroy = true; 1546 } 1547 } else { 1548 continue; 1549 } 1550 1551 unsigned index = capture.getIndex(); 1552 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1553 1554 // If there's an explicit copy expression, we do that. 1555 if (dtor) { 1556 PushDestructorCleanup(dtor, srcField); 1557 1558 // If this is a __weak capture, emit the release directly. 1559 } else if (useARCWeakDestroy) { 1560 EmitARCDestroyWeak(srcField); 1561 1562 // Destroy strong objects with a call if requested. 1563 } else if (useARCStrongDestroy) { 1564 EmitARCDestroyStrong(srcField, ARCImpreciseLifetime); 1565 1566 // Otherwise we call _Block_object_dispose. It wouldn't be too 1567 // hard to just emit this as a cleanup if we wanted to make sure 1568 // that things were done in reverse. 1569 } else { 1570 llvm::Value *value = Builder.CreateLoad(srcField); 1571 value = Builder.CreateBitCast(value, VoidPtrTy); 1572 BuildBlockRelease(value, flags); 1573 } 1574 } 1575 1576 cleanups.ForceCleanup(); 1577 1578 FinishFunction(); 1579 1580 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1581 } 1582 1583 namespace { 1584 1585 /// Emits the copy/dispose helper functions for a __block object of id type. 1586 class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers { 1587 BlockFieldFlags Flags; 1588 1589 public: 1590 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags) 1591 : ByrefHelpers(alignment), Flags(flags) {} 1592 1593 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1594 llvm::Value *srcField) { 1595 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy); 1596 1597 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy); 1598 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField); 1599 1600 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask(); 1601 1602 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags); 1603 llvm::Value *fn = CGF.CGM.getBlockObjectAssign(); 1604 1605 llvm::Value *args[] = { destField, srcValue, flagsVal }; 1606 CGF.EmitNounwindRuntimeCall(fn, args); 1607 } 1608 1609 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1610 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0)); 1611 llvm::Value *value = CGF.Builder.CreateLoad(field); 1612 1613 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER); 1614 } 1615 1616 void profileImpl(llvm::FoldingSetNodeID &id) const { 1617 id.AddInteger(Flags.getBitMask()); 1618 } 1619 }; 1620 1621 /// Emits the copy/dispose helpers for an ARC __block __weak variable. 1622 class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers { 1623 public: 1624 ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1625 1626 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1627 llvm::Value *srcField) { 1628 CGF.EmitARCMoveWeak(destField, srcField); 1629 } 1630 1631 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1632 CGF.EmitARCDestroyWeak(field); 1633 } 1634 1635 void profileImpl(llvm::FoldingSetNodeID &id) const { 1636 // 0 is distinguishable from all pointers and byref flags 1637 id.AddInteger(0); 1638 } 1639 }; 1640 1641 /// Emits the copy/dispose helpers for an ARC __block __strong variable 1642 /// that's not of block-pointer type. 1643 class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers { 1644 public: 1645 ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1646 1647 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1648 llvm::Value *srcField) { 1649 // Do a "move" by copying the value and then zeroing out the old 1650 // variable. 1651 1652 llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField); 1653 value->setAlignment(Alignment.getQuantity()); 1654 1655 llvm::Value *null = 1656 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType())); 1657 1658 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) { 1659 llvm::StoreInst *store = CGF.Builder.CreateStore(null, destField); 1660 store->setAlignment(Alignment.getQuantity()); 1661 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true); 1662 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true); 1663 return; 1664 } 1665 llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField); 1666 store->setAlignment(Alignment.getQuantity()); 1667 1668 store = CGF.Builder.CreateStore(null, srcField); 1669 store->setAlignment(Alignment.getQuantity()); 1670 } 1671 1672 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1673 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1674 } 1675 1676 void profileImpl(llvm::FoldingSetNodeID &id) const { 1677 // 1 is distinguishable from all pointers and byref flags 1678 id.AddInteger(1); 1679 } 1680 }; 1681 1682 /// Emits the copy/dispose helpers for an ARC __block __strong 1683 /// variable that's of block-pointer type. 1684 class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers { 1685 public: 1686 ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1687 1688 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1689 llvm::Value *srcField) { 1690 // Do the copy with objc_retainBlock; that's all that 1691 // _Block_object_assign would do anyway, and we'd have to pass the 1692 // right arguments to make sure it doesn't get no-op'ed. 1693 llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField); 1694 oldValue->setAlignment(Alignment.getQuantity()); 1695 1696 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true); 1697 1698 llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField); 1699 store->setAlignment(Alignment.getQuantity()); 1700 } 1701 1702 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1703 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1704 } 1705 1706 void profileImpl(llvm::FoldingSetNodeID &id) const { 1707 // 2 is distinguishable from all pointers and byref flags 1708 id.AddInteger(2); 1709 } 1710 }; 1711 1712 /// Emits the copy/dispose helpers for a __block variable with a 1713 /// nontrivial copy constructor or destructor. 1714 class CXXByrefHelpers : public CodeGenModule::ByrefHelpers { 1715 QualType VarType; 1716 const Expr *CopyExpr; 1717 1718 public: 1719 CXXByrefHelpers(CharUnits alignment, QualType type, 1720 const Expr *copyExpr) 1721 : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {} 1722 1723 bool needsCopy() const { return CopyExpr != 0; } 1724 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1725 llvm::Value *srcField) { 1726 if (!CopyExpr) return; 1727 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr); 1728 } 1729 1730 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1731 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin(); 1732 CGF.PushDestructorCleanup(VarType, field); 1733 CGF.PopCleanupBlocks(cleanupDepth); 1734 } 1735 1736 void profileImpl(llvm::FoldingSetNodeID &id) const { 1737 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr()); 1738 } 1739 }; 1740 } // end anonymous namespace 1741 1742 static llvm::Constant * 1743 generateByrefCopyHelper(CodeGenFunction &CGF, 1744 llvm::StructType &byrefType, 1745 unsigned valueFieldIndex, 1746 CodeGenModule::ByrefHelpers &byrefInfo) { 1747 ASTContext &Context = CGF.getContext(); 1748 1749 QualType R = Context.VoidTy; 1750 1751 FunctionArgList args; 1752 ImplicitParamDecl dst(0, SourceLocation(), 0, Context.VoidPtrTy); 1753 args.push_back(&dst); 1754 1755 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1756 args.push_back(&src); 1757 1758 const CGFunctionInfo &FI = 1759 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1760 FunctionType::ExtInfo(), 1761 /*variadic*/ false); 1762 1763 CodeGenTypes &Types = CGF.CGM.getTypes(); 1764 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1765 1766 // FIXME: We'd like to put these into a mergable by content, with 1767 // internal linkage. 1768 llvm::Function *Fn = 1769 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1770 "__Block_byref_object_copy_", &CGF.CGM.getModule()); 1771 1772 IdentifierInfo *II 1773 = &Context.Idents.get("__Block_byref_object_copy_"); 1774 1775 FunctionDecl *FD = FunctionDecl::Create(Context, 1776 Context.getTranslationUnitDecl(), 1777 SourceLocation(), 1778 SourceLocation(), II, R, 0, 1779 SC_Static, 1780 SC_None, 1781 false, false); 1782 1783 // Initialize debug info if necessary. 1784 CGF.maybeInitializeDebugInfo(); 1785 CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); 1786 1787 if (byrefInfo.needsCopy()) { 1788 llvm::Type *byrefPtrType = byrefType.getPointerTo(0); 1789 1790 // dst->x 1791 llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst); 1792 destField = CGF.Builder.CreateLoad(destField); 1793 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType); 1794 destField = CGF.Builder.CreateStructGEP(destField, valueFieldIndex, "x"); 1795 1796 // src->x 1797 llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src); 1798 srcField = CGF.Builder.CreateLoad(srcField); 1799 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType); 1800 srcField = CGF.Builder.CreateStructGEP(srcField, valueFieldIndex, "x"); 1801 1802 byrefInfo.emitCopy(CGF, destField, srcField); 1803 } 1804 1805 CGF.FinishFunction(); 1806 1807 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1808 } 1809 1810 /// Build the copy helper for a __block variable. 1811 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM, 1812 llvm::StructType &byrefType, 1813 unsigned byrefValueIndex, 1814 CodeGenModule::ByrefHelpers &info) { 1815 CodeGenFunction CGF(CGM); 1816 return generateByrefCopyHelper(CGF, byrefType, byrefValueIndex, info); 1817 } 1818 1819 /// Generate code for a __block variable's dispose helper. 1820 static llvm::Constant * 1821 generateByrefDisposeHelper(CodeGenFunction &CGF, 1822 llvm::StructType &byrefType, 1823 unsigned byrefValueIndex, 1824 CodeGenModule::ByrefHelpers &byrefInfo) { 1825 ASTContext &Context = CGF.getContext(); 1826 QualType R = Context.VoidTy; 1827 1828 FunctionArgList args; 1829 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1830 args.push_back(&src); 1831 1832 const CGFunctionInfo &FI = 1833 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1834 FunctionType::ExtInfo(), 1835 /*variadic*/ false); 1836 1837 CodeGenTypes &Types = CGF.CGM.getTypes(); 1838 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1839 1840 // FIXME: We'd like to put these into a mergable by content, with 1841 // internal linkage. 1842 llvm::Function *Fn = 1843 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1844 "__Block_byref_object_dispose_", 1845 &CGF.CGM.getModule()); 1846 1847 IdentifierInfo *II 1848 = &Context.Idents.get("__Block_byref_object_dispose_"); 1849 1850 FunctionDecl *FD = FunctionDecl::Create(Context, 1851 Context.getTranslationUnitDecl(), 1852 SourceLocation(), 1853 SourceLocation(), II, R, 0, 1854 SC_Static, 1855 SC_None, 1856 false, false); 1857 // Initialize debug info if necessary. 1858 CGF.maybeInitializeDebugInfo(); 1859 CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); 1860 1861 if (byrefInfo.needsDispose()) { 1862 llvm::Value *V = CGF.GetAddrOfLocalVar(&src); 1863 V = CGF.Builder.CreateLoad(V); 1864 V = CGF.Builder.CreateBitCast(V, byrefType.getPointerTo(0)); 1865 V = CGF.Builder.CreateStructGEP(V, byrefValueIndex, "x"); 1866 1867 byrefInfo.emitDispose(CGF, V); 1868 } 1869 1870 CGF.FinishFunction(); 1871 1872 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1873 } 1874 1875 /// Build the dispose helper for a __block variable. 1876 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM, 1877 llvm::StructType &byrefType, 1878 unsigned byrefValueIndex, 1879 CodeGenModule::ByrefHelpers &info) { 1880 CodeGenFunction CGF(CGM); 1881 return generateByrefDisposeHelper(CGF, byrefType, byrefValueIndex, info); 1882 } 1883 1884 /// Lazily build the copy and dispose helpers for a __block variable 1885 /// with the given information. 1886 template <class T> static T *buildByrefHelpers(CodeGenModule &CGM, 1887 llvm::StructType &byrefTy, 1888 unsigned byrefValueIndex, 1889 T &byrefInfo) { 1890 // Increase the field's alignment to be at least pointer alignment, 1891 // since the layout of the byref struct will guarantee at least that. 1892 byrefInfo.Alignment = std::max(byrefInfo.Alignment, 1893 CharUnits::fromQuantity(CGM.PointerAlignInBytes)); 1894 1895 llvm::FoldingSetNodeID id; 1896 byrefInfo.Profile(id); 1897 1898 void *insertPos; 1899 CodeGenModule::ByrefHelpers *node 1900 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos); 1901 if (node) return static_cast<T*>(node); 1902 1903 byrefInfo.CopyHelper = 1904 buildByrefCopyHelper(CGM, byrefTy, byrefValueIndex, byrefInfo); 1905 byrefInfo.DisposeHelper = 1906 buildByrefDisposeHelper(CGM, byrefTy, byrefValueIndex,byrefInfo); 1907 1908 T *copy = new (CGM.getContext()) T(byrefInfo); 1909 CGM.ByrefHelpersCache.InsertNode(copy, insertPos); 1910 return copy; 1911 } 1912 1913 /// Build the copy and dispose helpers for the given __block variable 1914 /// emission. Places the helpers in the global cache. Returns null 1915 /// if no helpers are required. 1916 CodeGenModule::ByrefHelpers * 1917 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType, 1918 const AutoVarEmission &emission) { 1919 const VarDecl &var = *emission.Variable; 1920 QualType type = var.getType(); 1921 1922 unsigned byrefValueIndex = getByRefValueLLVMField(&var); 1923 1924 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1925 const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var); 1926 if (!copyExpr && record->hasTrivialDestructor()) return 0; 1927 1928 CXXByrefHelpers byrefInfo(emission.Alignment, type, copyExpr); 1929 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1930 } 1931 1932 // Otherwise, if we don't have a retainable type, there's nothing to do. 1933 // that the runtime does extra copies. 1934 if (!type->isObjCRetainableType()) return 0; 1935 1936 Qualifiers qs = type.getQualifiers(); 1937 1938 // If we have lifetime, that dominates. 1939 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) { 1940 assert(getLangOpts().ObjCAutoRefCount); 1941 1942 switch (lifetime) { 1943 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 1944 1945 // These are just bits as far as the runtime is concerned. 1946 case Qualifiers::OCL_ExplicitNone: 1947 case Qualifiers::OCL_Autoreleasing: 1948 return 0; 1949 1950 // Tell the runtime that this is ARC __weak, called by the 1951 // byref routines. 1952 case Qualifiers::OCL_Weak: { 1953 ARCWeakByrefHelpers byrefInfo(emission.Alignment); 1954 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1955 } 1956 1957 // ARC __strong __block variables need to be retained. 1958 case Qualifiers::OCL_Strong: 1959 // Block pointers need to be copied, and there's no direct 1960 // transfer possible. 1961 if (type->isBlockPointerType()) { 1962 ARCStrongBlockByrefHelpers byrefInfo(emission.Alignment); 1963 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1964 1965 // Otherwise, we transfer ownership of the retain from the stack 1966 // to the heap. 1967 } else { 1968 ARCStrongByrefHelpers byrefInfo(emission.Alignment); 1969 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1970 } 1971 } 1972 llvm_unreachable("fell out of lifetime switch!"); 1973 } 1974 1975 BlockFieldFlags flags; 1976 if (type->isBlockPointerType()) { 1977 flags |= BLOCK_FIELD_IS_BLOCK; 1978 } else if (CGM.getContext().isObjCNSObjectType(type) || 1979 type->isObjCObjectPointerType()) { 1980 flags |= BLOCK_FIELD_IS_OBJECT; 1981 } else { 1982 return 0; 1983 } 1984 1985 if (type.isObjCGCWeak()) 1986 flags |= BLOCK_FIELD_IS_WEAK; 1987 1988 ObjectByrefHelpers byrefInfo(emission.Alignment, flags); 1989 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1990 } 1991 1992 unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const { 1993 assert(ByRefValueInfo.count(VD) && "Did not find value!"); 1994 1995 return ByRefValueInfo.find(VD)->second.second; 1996 } 1997 1998 llvm::Value *CodeGenFunction::BuildBlockByrefAddress(llvm::Value *BaseAddr, 1999 const VarDecl *V) { 2000 llvm::Value *Loc = Builder.CreateStructGEP(BaseAddr, 1, "forwarding"); 2001 Loc = Builder.CreateLoad(Loc); 2002 Loc = Builder.CreateStructGEP(Loc, getByRefValueLLVMField(V), 2003 V->getNameAsString()); 2004 return Loc; 2005 } 2006 2007 /// BuildByRefType - This routine changes a __block variable declared as T x 2008 /// into: 2009 /// 2010 /// struct { 2011 /// void *__isa; 2012 /// void *__forwarding; 2013 /// int32_t __flags; 2014 /// int32_t __size; 2015 /// void *__copy_helper; // only if needed 2016 /// void *__destroy_helper; // only if needed 2017 /// void *__byref_variable_layout;// only if needed 2018 /// char padding[X]; // only if needed 2019 /// T x; 2020 /// } x 2021 /// 2022 llvm::Type *CodeGenFunction::BuildByRefType(const VarDecl *D) { 2023 std::pair<llvm::Type *, unsigned> &Info = ByRefValueInfo[D]; 2024 if (Info.first) 2025 return Info.first; 2026 2027 QualType Ty = D->getType(); 2028 2029 SmallVector<llvm::Type *, 8> types; 2030 2031 llvm::StructType *ByRefType = 2032 llvm::StructType::create(getLLVMContext(), 2033 "struct.__block_byref_" + D->getNameAsString()); 2034 2035 // void *__isa; 2036 types.push_back(Int8PtrTy); 2037 2038 // void *__forwarding; 2039 types.push_back(llvm::PointerType::getUnqual(ByRefType)); 2040 2041 // int32_t __flags; 2042 types.push_back(Int32Ty); 2043 2044 // int32_t __size; 2045 types.push_back(Int32Ty); 2046 // Note that this must match *exactly* the logic in buildByrefHelpers. 2047 bool HasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D); 2048 if (HasCopyAndDispose) { 2049 /// void *__copy_helper; 2050 types.push_back(Int8PtrTy); 2051 2052 /// void *__destroy_helper; 2053 types.push_back(Int8PtrTy); 2054 } 2055 bool HasByrefExtendedLayout = false; 2056 Qualifiers::ObjCLifetime Lifetime; 2057 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) && 2058 HasByrefExtendedLayout) 2059 /// void *__byref_variable_layout; 2060 types.push_back(Int8PtrTy); 2061 2062 bool Packed = false; 2063 CharUnits Align = getContext().getDeclAlign(D); 2064 if (Align > getContext().toCharUnitsFromBits(Target.getPointerAlign(0))) { 2065 // We have to insert padding. 2066 2067 // The struct above has 2 32-bit integers. 2068 unsigned CurrentOffsetInBytes = 4 * 2; 2069 2070 // And either 2, 3, 4 or 5 pointers. 2071 unsigned noPointers = 2; 2072 if (HasCopyAndDispose) 2073 noPointers += 2; 2074 if (HasByrefExtendedLayout) 2075 noPointers += 1; 2076 2077 CurrentOffsetInBytes += noPointers * CGM.getDataLayout().getTypeAllocSize(Int8PtrTy); 2078 2079 // Align the offset. 2080 unsigned AlignedOffsetInBytes = 2081 llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity()); 2082 2083 unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes; 2084 if (NumPaddingBytes > 0) { 2085 llvm::Type *Ty = Int8Ty; 2086 // FIXME: We need a sema error for alignment larger than the minimum of 2087 // the maximal stack alignment and the alignment of malloc on the system. 2088 if (NumPaddingBytes > 1) 2089 Ty = llvm::ArrayType::get(Ty, NumPaddingBytes); 2090 2091 types.push_back(Ty); 2092 2093 // We want a packed struct. 2094 Packed = true; 2095 } 2096 } 2097 2098 // T x; 2099 types.push_back(ConvertTypeForMem(Ty)); 2100 2101 ByRefType->setBody(types, Packed); 2102 2103 Info.first = ByRefType; 2104 2105 Info.second = types.size() - 1; 2106 2107 return Info.first; 2108 } 2109 2110 /// Initialize the structural components of a __block variable, i.e. 2111 /// everything but the actual object. 2112 void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) { 2113 // Find the address of the local. 2114 llvm::Value *addr = emission.Address; 2115 2116 // That's an alloca of the byref structure type. 2117 llvm::StructType *byrefType = cast<llvm::StructType>( 2118 cast<llvm::PointerType>(addr->getType())->getElementType()); 2119 2120 // Build the byref helpers if necessary. This is null if we don't need any. 2121 CodeGenModule::ByrefHelpers *helpers = 2122 buildByrefHelpers(*byrefType, emission); 2123 2124 const VarDecl &D = *emission.Variable; 2125 QualType type = D.getType(); 2126 2127 bool HasByrefExtendedLayout; 2128 Qualifiers::ObjCLifetime ByrefLifetime; 2129 bool ByRefHasLifetime = 2130 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout); 2131 2132 llvm::Value *V; 2133 2134 // Initialize the 'isa', which is just 0 or 1. 2135 int isa = 0; 2136 if (type.isObjCGCWeak()) 2137 isa = 1; 2138 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa"); 2139 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 0, "byref.isa")); 2140 2141 // Store the address of the variable into its own forwarding pointer. 2142 Builder.CreateStore(addr, 2143 Builder.CreateStructGEP(addr, 1, "byref.forwarding")); 2144 2145 // Blocks ABI: 2146 // c) the flags field is set to either 0 if no helper functions are 2147 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are, 2148 BlockFlags flags; 2149 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE; 2150 if (ByRefHasLifetime) { 2151 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED; 2152 else switch (ByrefLifetime) { 2153 case Qualifiers::OCL_Strong: 2154 flags |= BLOCK_BYREF_LAYOUT_STRONG; 2155 break; 2156 case Qualifiers::OCL_Weak: 2157 flags |= BLOCK_BYREF_LAYOUT_WEAK; 2158 break; 2159 case Qualifiers::OCL_ExplicitNone: 2160 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED; 2161 break; 2162 case Qualifiers::OCL_None: 2163 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType()) 2164 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT; 2165 break; 2166 default: 2167 break; 2168 } 2169 if (CGM.getLangOpts().ObjCGCBitmapPrint) { 2170 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask()); 2171 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE) 2172 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE"); 2173 if (flags & BLOCK_BYREF_LAYOUT_MASK) { 2174 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK); 2175 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED) 2176 printf(" BLOCK_BYREF_LAYOUT_EXTENDED"); 2177 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG) 2178 printf(" BLOCK_BYREF_LAYOUT_STRONG"); 2179 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK) 2180 printf(" BLOCK_BYREF_LAYOUT_WEAK"); 2181 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED) 2182 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED"); 2183 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT) 2184 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT"); 2185 } 2186 printf("\n"); 2187 } 2188 } 2189 2190 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 2191 Builder.CreateStructGEP(addr, 2, "byref.flags")); 2192 2193 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType); 2194 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity()); 2195 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 3, "byref.size")); 2196 2197 if (helpers) { 2198 llvm::Value *copy_helper = Builder.CreateStructGEP(addr, 4); 2199 Builder.CreateStore(helpers->CopyHelper, copy_helper); 2200 2201 llvm::Value *destroy_helper = Builder.CreateStructGEP(addr, 5); 2202 Builder.CreateStore(helpers->DisposeHelper, destroy_helper); 2203 } 2204 if (ByRefHasLifetime && HasByrefExtendedLayout) { 2205 llvm::Constant* ByrefLayoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type); 2206 llvm::Value *ByrefInfoAddr = Builder.CreateStructGEP(addr, helpers ? 6 : 4, 2207 "byref.layout"); 2208 // cast destination to pointer to source type. 2209 llvm::Type *DesTy = ByrefLayoutInfo->getType(); 2210 DesTy = DesTy->getPointerTo(); 2211 llvm::Value *BC = Builder.CreatePointerCast(ByrefInfoAddr, DesTy); 2212 Builder.CreateStore(ByrefLayoutInfo, BC); 2213 } 2214 } 2215 2216 void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) { 2217 llvm::Value *F = CGM.getBlockObjectDispose(); 2218 llvm::Value *args[] = { 2219 Builder.CreateBitCast(V, Int8PtrTy), 2220 llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 2221 }; 2222 EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors? 2223 } 2224 2225 namespace { 2226 struct CallBlockRelease : EHScopeStack::Cleanup { 2227 llvm::Value *Addr; 2228 CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {} 2229 2230 void Emit(CodeGenFunction &CGF, Flags flags) { 2231 // Should we be passing FIELD_IS_WEAK here? 2232 CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF); 2233 } 2234 }; 2235 } 2236 2237 /// Enter a cleanup to destroy a __block variable. Note that this 2238 /// cleanup should be a no-op if the variable hasn't left the stack 2239 /// yet; if a cleanup is required for the variable itself, that needs 2240 /// to be done externally. 2241 void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) { 2242 // We don't enter this cleanup if we're in pure-GC mode. 2243 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) 2244 return; 2245 2246 EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address); 2247 } 2248 2249 /// Adjust the declaration of something from the blocks API. 2250 static void configureBlocksRuntimeObject(CodeGenModule &CGM, 2251 llvm::Constant *C) { 2252 if (!CGM.getLangOpts().BlocksRuntimeOptional) return; 2253 2254 llvm::GlobalValue *GV = cast<llvm::GlobalValue>(C->stripPointerCasts()); 2255 if (GV->isDeclaration() && 2256 GV->getLinkage() == llvm::GlobalValue::ExternalLinkage) 2257 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 2258 } 2259 2260 llvm::Constant *CodeGenModule::getBlockObjectDispose() { 2261 if (BlockObjectDispose) 2262 return BlockObjectDispose; 2263 2264 llvm::Type *args[] = { Int8PtrTy, Int32Ty }; 2265 llvm::FunctionType *fty 2266 = llvm::FunctionType::get(VoidTy, args, false); 2267 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose"); 2268 configureBlocksRuntimeObject(*this, BlockObjectDispose); 2269 return BlockObjectDispose; 2270 } 2271 2272 llvm::Constant *CodeGenModule::getBlockObjectAssign() { 2273 if (BlockObjectAssign) 2274 return BlockObjectAssign; 2275 2276 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty }; 2277 llvm::FunctionType *fty 2278 = llvm::FunctionType::get(VoidTy, args, false); 2279 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign"); 2280 configureBlocksRuntimeObject(*this, BlockObjectAssign); 2281 return BlockObjectAssign; 2282 } 2283 2284 llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { 2285 if (NSConcreteGlobalBlock) 2286 return NSConcreteGlobalBlock; 2287 2288 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock", 2289 Int8PtrTy->getPointerTo(), 0); 2290 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock); 2291 return NSConcreteGlobalBlock; 2292 } 2293 2294 llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { 2295 if (NSConcreteStackBlock) 2296 return NSConcreteStackBlock; 2297 2298 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock", 2299 Int8PtrTy->getPointerTo(), 0); 2300 configureBlocksRuntimeObject(*this, NSConcreteStackBlock); 2301 return NSConcreteStackBlock; 2302 } 2303