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 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(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. 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 dipose 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/// 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/// }; 74static 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. 179const unsigned BlockHeaderSize = 5; 180 181namespace { 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++. 240static 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. 264static 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. 291static CharUnits getLowBit(CharUnits v) { 292 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1)); 293} 294 295static 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. 329static 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. 561static 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*. 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 != 0); 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 OwningPtr<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 (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 CharUnits align = getContext().getDeclAlign(variable); 757 758 // This will be a [[type]]*, except that a byref entry will just be 759 // an i8**. 760 llvm::Value *blockField = 761 Builder.CreateStructGEP(blockAddr, capture.getIndex(), 762 "block.captured"); 763 764 // Compute the address of the thing we're going to move into the 765 // block literal. 766 llvm::Value *src; 767 if (BlockInfo && ci->isNested()) { 768 // We need to use the capture from the enclosing block. 769 const CGBlockInfo::Capture &enclosingCapture = 770 BlockInfo->getCapture(variable); 771 772 // This is a [[type]]*, except that a byref entry wil just be an i8**. 773 src = Builder.CreateStructGEP(LoadBlockStruct(), 774 enclosingCapture.getIndex(), 775 "block.capture.addr"); 776 } else if (blockDecl->isConversionFromLambda()) { 777 // The lambda capture in a lambda's conversion-to-block-pointer is 778 // special; we'll simply emit it directly. 779 src = 0; 780 } else { 781 // Just look it up in the locals map, which will give us back a 782 // [[type]]*. If that doesn't work, do the more elaborate DRE 783 // emission. 784 src = LocalDeclMap.lookup(variable); 785 if (!src) { 786 DeclRefExpr declRef(const_cast<VarDecl*>(variable), 787 /*refersToEnclosing*/ ci->isNested(), type, 788 VK_LValue, SourceLocation()); 789 src = EmitDeclRefLValue(&declRef).getAddress(); 790 } 791 } 792 793 // For byrefs, we just write the pointer to the byref struct into 794 // the block field. There's no need to chase the forwarding 795 // pointer at this point, since we're building something that will 796 // live a shorter life than the stack byref anyway. 797 if (ci->isByRef()) { 798 // Get a void* that points to the byref struct. 799 if (ci->isNested()) 800 src = Builder.CreateAlignedLoad(src, align.getQuantity(), 801 "byref.capture"); 802 else 803 src = Builder.CreateBitCast(src, VoidPtrTy); 804 805 // Write that void* into the capture field. 806 Builder.CreateAlignedStore(src, blockField, align.getQuantity()); 807 808 // If we have a copy constructor, evaluate that into the block field. 809 } else if (const Expr *copyExpr = ci->getCopyExpr()) { 810 if (blockDecl->isConversionFromLambda()) { 811 // If we have a lambda conversion, emit the expression 812 // directly into the block instead. 813 AggValueSlot Slot = 814 AggValueSlot::forAddr(blockField, align, Qualifiers(), 815 AggValueSlot::IsDestructed, 816 AggValueSlot::DoesNotNeedGCBarriers, 817 AggValueSlot::IsNotAliased); 818 EmitAggExpr(copyExpr, Slot); 819 } else { 820 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr); 821 } 822 823 // If it's a reference variable, copy the reference into the block field. 824 } else if (type->isReferenceType()) { 825 llvm::Value *ref = 826 Builder.CreateAlignedLoad(src, align.getQuantity(), "ref.val"); 827 Builder.CreateAlignedStore(ref, blockField, align.getQuantity()); 828 829 // If this is an ARC __strong block-pointer variable, don't do a 830 // block copy. 831 // 832 // TODO: this can be generalized into the normal initialization logic: 833 // we should never need to do a block-copy when initializing a local 834 // variable, because the local variable's lifetime should be strictly 835 // contained within the stack block's. 836 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong && 837 type->isBlockPointerType()) { 838 // Load the block and do a simple retain. 839 LValue srcLV = MakeAddrLValue(src, type, align); 840 llvm::Value *value = EmitLoadOfScalar(srcLV); 841 value = EmitARCRetainNonBlock(value); 842 843 // Do a primitive store to the block field. 844 LValue destLV = MakeAddrLValue(blockField, type, align); 845 EmitStoreOfScalar(value, destLV, /*init*/ true); 846 847 // Otherwise, fake up a POD copy into the block field. 848 } else { 849 // Fake up a new variable so that EmitScalarInit doesn't think 850 // we're referring to the variable in its own initializer. 851 ImplicitParamDecl blockFieldPseudoVar(/*DC*/ 0, SourceLocation(), 852 /*name*/ 0, 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, 0, 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 // Check if we should generate debug info for this block function. 1096 maybeInitializeDebugInfo(); 1097 CurGD = GD; 1098 1099 BlockInfo = &blockInfo; 1100 1101 // Arrange for local static and local extern declarations to appear 1102 // to be local to this function as well, in case they're directly 1103 // referenced in a block. 1104 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) { 1105 const VarDecl *var = dyn_cast<VarDecl>(i->first); 1106 if (var && !var->hasLocalStorage()) 1107 LocalDeclMap[var] = i->second; 1108 } 1109 1110 // Begin building the function declaration. 1111 1112 // Build the argument list. 1113 FunctionArgList args; 1114 1115 // The first argument is the block pointer. Just take it as a void* 1116 // and cast it later. 1117 QualType selfTy = getContext().VoidPtrTy; 1118 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor"); 1119 1120 ImplicitParamDecl selfDecl(const_cast<BlockDecl*>(blockDecl), 1121 SourceLocation(), II, selfTy); 1122 args.push_back(&selfDecl); 1123 1124 // Now add the rest of the parameters. 1125 for (BlockDecl::param_const_iterator i = blockDecl->param_begin(), 1126 e = blockDecl->param_end(); i != e; ++i) 1127 args.push_back(*i); 1128 1129 // Create the function declaration. 1130 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType(); 1131 const CGFunctionInfo &fnInfo = 1132 CGM.getTypes().arrangeFunctionDeclaration(fnType->getResultType(), args, 1133 fnType->getExtInfo(), 1134 fnType->isVariadic()); 1135 if (CGM.ReturnTypeUsesSRet(fnInfo)) 1136 blockInfo.UsesStret = true; 1137 1138 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo); 1139 1140 MangleBuffer name; 1141 CGM.getBlockMangledName(GD, name, blockDecl); 1142 llvm::Function *fn = 1143 llvm::Function::Create(fnLLVMType, llvm::GlobalValue::InternalLinkage, 1144 name.getString(), &CGM.getModule()); 1145 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo); 1146 1147 // Begin generating the function. 1148 StartFunction(blockDecl, fnType->getResultType(), fn, fnInfo, args, 1149 blockInfo.getBlockExpr()->getBody()->getLocStart()); 1150 1151 // Okay. Undo some of what StartFunction did. 1152 1153 // Pull the 'self' reference out of the local decl map. 1154 llvm::Value *blockAddr = LocalDeclMap[&selfDecl]; 1155 LocalDeclMap.erase(&selfDecl); 1156 BlockPointer = Builder.CreateBitCast(blockAddr, 1157 blockInfo.StructureType->getPointerTo(), 1158 "block"); 1159 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA 1160 // won't delete the dbg.declare intrinsics for captured variables. 1161 llvm::Value *BlockPointerDbgLoc = BlockPointer; 1162 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1163 // Allocate a stack slot for it, so we can point the debugger to it 1164 llvm::AllocaInst *Alloca = CreateTempAlloca(BlockPointer->getType(), 1165 "block.addr"); 1166 unsigned Align = getContext().getDeclAlign(&selfDecl).getQuantity(); 1167 Alloca->setAlignment(Align); 1168 // Set the DebugLocation to empty, so the store is recognized as a 1169 // frame setup instruction by llvm::DwarfDebug::beginFunction(). 1170 Builder.DisableDebugLocations(); 1171 Builder.CreateAlignedStore(BlockPointer, Alloca, Align); 1172 Builder.EnableDebugLocations(); 1173 BlockPointerDbgLoc = Alloca; 1174 } 1175 1176 // If we have a C++ 'this' reference, go ahead and force it into 1177 // existence now. 1178 if (blockDecl->capturesCXXThis()) { 1179 llvm::Value *addr = Builder.CreateStructGEP(BlockPointer, 1180 blockInfo.CXXThisIndex, 1181 "block.captured-this"); 1182 CXXThisValue = Builder.CreateLoad(addr, "this"); 1183 } 1184 1185 // Also force all the constant captures. 1186 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1187 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1188 const VarDecl *variable = ci->getVariable(); 1189 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1190 if (!capture.isConstant()) continue; 1191 1192 unsigned align = getContext().getDeclAlign(variable).getQuantity(); 1193 1194 llvm::AllocaInst *alloca = 1195 CreateMemTemp(variable->getType(), "block.captured-const"); 1196 alloca->setAlignment(align); 1197 1198 Builder.CreateAlignedStore(capture.getConstant(), alloca, align); 1199 1200 LocalDeclMap[variable] = alloca; 1201 } 1202 1203 // Save a spot to insert the debug information for all the DeclRefExprs. 1204 llvm::BasicBlock *entry = Builder.GetInsertBlock(); 1205 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); 1206 --entry_ptr; 1207 1208 if (IsLambdaConversionToBlock) 1209 EmitLambdaBlockInvokeBody(); 1210 else 1211 EmitStmt(blockDecl->getBody()); 1212 1213 // Remember where we were... 1214 llvm::BasicBlock *resume = Builder.GetInsertBlock(); 1215 1216 // Go back to the entry. 1217 ++entry_ptr; 1218 Builder.SetInsertPoint(entry, entry_ptr); 1219 1220 // Emit debug information for all the DeclRefExprs. 1221 // FIXME: also for 'this' 1222 if (CGDebugInfo *DI = getDebugInfo()) { 1223 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1224 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1225 const VarDecl *variable = ci->getVariable(); 1226 DI->EmitLocation(Builder, variable->getLocation()); 1227 1228 if (CGM.getCodeGenOpts().getDebugInfo() 1229 >= CodeGenOptions::LimitedDebugInfo) { 1230 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1231 if (capture.isConstant()) { 1232 DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], 1233 Builder); 1234 continue; 1235 } 1236 1237 DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointerDbgLoc, 1238 Builder, blockInfo); 1239 } 1240 } 1241 // Recover location if it was changed in the above loop. 1242 DI->EmitLocation(Builder, 1243 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1244 } 1245 1246 // And resume where we left off. 1247 if (resume == 0) 1248 Builder.ClearInsertionPoint(); 1249 else 1250 Builder.SetInsertPoint(resume); 1251 1252 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1253 1254 return fn; 1255} 1256 1257/* 1258 notes.push_back(HelperInfo()); 1259 HelperInfo ¬e = notes.back(); 1260 note.index = capture.getIndex(); 1261 note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type)); 1262 note.cxxbar_import = ci->getCopyExpr(); 1263 1264 if (ci->isByRef()) { 1265 note.flag = BLOCK_FIELD_IS_BYREF; 1266 if (type.isObjCGCWeak()) 1267 note.flag |= BLOCK_FIELD_IS_WEAK; 1268 } else if (type->isBlockPointerType()) { 1269 note.flag = BLOCK_FIELD_IS_BLOCK; 1270 } else { 1271 note.flag = BLOCK_FIELD_IS_OBJECT; 1272 } 1273 */ 1274 1275 1276/// Generate the copy-helper function for a block closure object: 1277/// static void block_copy_helper(block_t *dst, block_t *src); 1278/// The runtime will have previously initialized 'dst' by doing a 1279/// bit-copy of 'src'. 1280/// 1281/// Note that this copies an entire block closure object to the heap; 1282/// it should not be confused with a 'byref copy helper', which moves 1283/// the contents of an individual __block variable to the heap. 1284llvm::Constant * 1285CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) { 1286 ASTContext &C = getContext(); 1287 1288 FunctionArgList args; 1289 ImplicitParamDecl dstDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1290 args.push_back(&dstDecl); 1291 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1292 args.push_back(&srcDecl); 1293 1294 const CGFunctionInfo &FI = 1295 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1296 FunctionType::ExtInfo(), 1297 /*variadic*/ false); 1298 1299 // FIXME: it would be nice if these were mergeable with things with 1300 // identical semantics. 1301 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1302 1303 llvm::Function *Fn = 1304 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1305 "__copy_helper_block_", &CGM.getModule()); 1306 1307 IdentifierInfo *II 1308 = &CGM.getContext().Idents.get("__copy_helper_block_"); 1309 1310 // Check if we should generate debug info for this block helper function. 1311 maybeInitializeDebugInfo(); 1312 1313 FunctionDecl *FD = FunctionDecl::Create(C, 1314 C.getTranslationUnitDecl(), 1315 SourceLocation(), 1316 SourceLocation(), II, C.VoidTy, 0, 1317 SC_Static, 1318 false, 1319 false); 1320 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1321 1322 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1323 1324 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1325 src = Builder.CreateLoad(src); 1326 src = Builder.CreateBitCast(src, structPtrTy, "block.source"); 1327 1328 llvm::Value *dst = GetAddrOfLocalVar(&dstDecl); 1329 dst = Builder.CreateLoad(dst); 1330 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest"); 1331 1332 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1333 1334 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1335 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1336 const VarDecl *variable = ci->getVariable(); 1337 QualType type = variable->getType(); 1338 1339 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1340 if (capture.isConstant()) continue; 1341 1342 const Expr *copyExpr = ci->getCopyExpr(); 1343 BlockFieldFlags flags; 1344 1345 bool useARCWeakCopy = false; 1346 bool useARCStrongCopy = false; 1347 1348 if (copyExpr) { 1349 assert(!ci->isByRef()); 1350 // don't bother computing flags 1351 1352 } else if (ci->isByRef()) { 1353 flags = BLOCK_FIELD_IS_BYREF; 1354 if (type.isObjCGCWeak()) 1355 flags |= BLOCK_FIELD_IS_WEAK; 1356 1357 } else if (type->isObjCRetainableType()) { 1358 flags = BLOCK_FIELD_IS_OBJECT; 1359 bool isBlockPointer = type->isBlockPointerType(); 1360 if (isBlockPointer) 1361 flags = BLOCK_FIELD_IS_BLOCK; 1362 1363 // Special rules for ARC captures: 1364 if (getLangOpts().ObjCAutoRefCount) { 1365 Qualifiers qs = type.getQualifiers(); 1366 1367 // We need to register __weak direct captures with the runtime. 1368 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) { 1369 useARCWeakCopy = true; 1370 1371 // We need to retain the copied value for __strong direct captures. 1372 } else if (qs.getObjCLifetime() == Qualifiers::OCL_Strong) { 1373 // If it's a block pointer, we have to copy the block and 1374 // assign that to the destination pointer, so we might as 1375 // well use _Block_object_assign. Otherwise we can avoid that. 1376 if (!isBlockPointer) 1377 useARCStrongCopy = true; 1378 1379 // Otherwise the memcpy is fine. 1380 } else { 1381 continue; 1382 } 1383 1384 // Non-ARC captures of retainable pointers are strong and 1385 // therefore require a call to _Block_object_assign. 1386 } else { 1387 // fall through 1388 } 1389 } else { 1390 continue; 1391 } 1392 1393 unsigned index = capture.getIndex(); 1394 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1395 llvm::Value *dstField = Builder.CreateStructGEP(dst, index); 1396 1397 // If there's an explicit copy expression, we do that. 1398 if (copyExpr) { 1399 EmitSynthesizedCXXCopyCtor(dstField, srcField, copyExpr); 1400 } else if (useARCWeakCopy) { 1401 EmitARCCopyWeak(dstField, srcField); 1402 } else { 1403 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src"); 1404 if (useARCStrongCopy) { 1405 // At -O0, store null into the destination field (so that the 1406 // storeStrong doesn't over-release) and then call storeStrong. 1407 // This is a workaround to not having an initStrong call. 1408 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1409 llvm::PointerType *ty = cast<llvm::PointerType>(srcValue->getType()); 1410 llvm::Value *null = llvm::ConstantPointerNull::get(ty); 1411 Builder.CreateStore(null, dstField); 1412 EmitARCStoreStrongCall(dstField, srcValue, true); 1413 1414 // With optimization enabled, take advantage of the fact that 1415 // the blocks runtime guarantees a memcpy of the block data, and 1416 // just emit a retain of the src field. 1417 } else { 1418 EmitARCRetainNonBlock(srcValue); 1419 1420 // We don't need this anymore, so kill it. It's not quite 1421 // worth the annoyance to avoid creating it in the first place. 1422 cast<llvm::Instruction>(dstField)->eraseFromParent(); 1423 } 1424 } else { 1425 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy); 1426 llvm::Value *dstAddr = Builder.CreateBitCast(dstField, VoidPtrTy); 1427 llvm::Value *args[] = { 1428 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 1429 }; 1430 1431 bool copyCanThrow = false; 1432 if (ci->isByRef() && variable->getType()->getAsCXXRecordDecl()) { 1433 const Expr *copyExpr = 1434 CGM.getContext().getBlockVarCopyInits(variable); 1435 if (copyExpr) { 1436 copyCanThrow = true; // FIXME: reuse the noexcept logic 1437 } 1438 } 1439 1440 if (copyCanThrow) { 1441 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args); 1442 } else { 1443 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args); 1444 } 1445 } 1446 } 1447 } 1448 1449 FinishFunction(); 1450 1451 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1452} 1453 1454/// Generate the destroy-helper function for a block closure object: 1455/// static void block_destroy_helper(block_t *theBlock); 1456/// 1457/// Note that this destroys a heap-allocated block closure object; 1458/// it should not be confused with a 'byref destroy helper', which 1459/// destroys the heap-allocated contents of an individual __block 1460/// variable. 1461llvm::Constant * 1462CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { 1463 ASTContext &C = getContext(); 1464 1465 FunctionArgList args; 1466 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1467 args.push_back(&srcDecl); 1468 1469 const CGFunctionInfo &FI = 1470 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1471 FunctionType::ExtInfo(), 1472 /*variadic*/ false); 1473 1474 // FIXME: We'd like to put these into a mergable by content, with 1475 // internal linkage. 1476 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1477 1478 llvm::Function *Fn = 1479 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1480 "__destroy_helper_block_", &CGM.getModule()); 1481 1482 // Check if we should generate debug info for this block destroy function. 1483 maybeInitializeDebugInfo(); 1484 1485 IdentifierInfo *II 1486 = &CGM.getContext().Idents.get("__destroy_helper_block_"); 1487 1488 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), 1489 SourceLocation(), 1490 SourceLocation(), II, C.VoidTy, 0, 1491 SC_Static, 1492 false, false); 1493 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1494 1495 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1496 1497 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1498 src = Builder.CreateLoad(src); 1499 src = Builder.CreateBitCast(src, structPtrTy, "block"); 1500 1501 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1502 1503 CodeGenFunction::RunCleanupsScope cleanups(*this); 1504 1505 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1506 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1507 const VarDecl *variable = ci->getVariable(); 1508 QualType type = variable->getType(); 1509 1510 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1511 if (capture.isConstant()) continue; 1512 1513 BlockFieldFlags flags; 1514 const CXXDestructorDecl *dtor = 0; 1515 1516 bool useARCWeakDestroy = false; 1517 bool useARCStrongDestroy = false; 1518 1519 if (ci->isByRef()) { 1520 flags = BLOCK_FIELD_IS_BYREF; 1521 if (type.isObjCGCWeak()) 1522 flags |= BLOCK_FIELD_IS_WEAK; 1523 } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1524 if (record->hasTrivialDestructor()) 1525 continue; 1526 dtor = record->getDestructor(); 1527 } else if (type->isObjCRetainableType()) { 1528 flags = BLOCK_FIELD_IS_OBJECT; 1529 if (type->isBlockPointerType()) 1530 flags = BLOCK_FIELD_IS_BLOCK; 1531 1532 // Special rules for ARC captures. 1533 if (getLangOpts().ObjCAutoRefCount) { 1534 Qualifiers qs = type.getQualifiers(); 1535 1536 // Don't generate special dispose logic for a captured object 1537 // unless it's __strong or __weak. 1538 if (!qs.hasStrongOrWeakObjCLifetime()) 1539 continue; 1540 1541 // Support __weak direct captures. 1542 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) 1543 useARCWeakDestroy = true; 1544 1545 // Tools really want us to use objc_storeStrong here. 1546 else 1547 useARCStrongDestroy = true; 1548 } 1549 } else { 1550 continue; 1551 } 1552 1553 unsigned index = capture.getIndex(); 1554 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1555 1556 // If there's an explicit copy expression, we do that. 1557 if (dtor) { 1558 PushDestructorCleanup(dtor, srcField); 1559 1560 // If this is a __weak capture, emit the release directly. 1561 } else if (useARCWeakDestroy) { 1562 EmitARCDestroyWeak(srcField); 1563 1564 // Destroy strong objects with a call if requested. 1565 } else if (useARCStrongDestroy) { 1566 EmitARCDestroyStrong(srcField, ARCImpreciseLifetime); 1567 1568 // Otherwise we call _Block_object_dispose. It wouldn't be too 1569 // hard to just emit this as a cleanup if we wanted to make sure 1570 // that things were done in reverse. 1571 } else { 1572 llvm::Value *value = Builder.CreateLoad(srcField); 1573 value = Builder.CreateBitCast(value, VoidPtrTy); 1574 BuildBlockRelease(value, flags); 1575 } 1576 } 1577 1578 cleanups.ForceCleanup(); 1579 1580 FinishFunction(); 1581 1582 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1583} 1584 1585namespace { 1586 1587/// Emits the copy/dispose helper functions for a __block object of id type. 1588class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers { 1589 BlockFieldFlags Flags; 1590 1591public: 1592 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags) 1593 : ByrefHelpers(alignment), Flags(flags) {} 1594 1595 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1596 llvm::Value *srcField) { 1597 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy); 1598 1599 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy); 1600 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField); 1601 1602 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask(); 1603 1604 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags); 1605 llvm::Value *fn = CGF.CGM.getBlockObjectAssign(); 1606 1607 llvm::Value *args[] = { destField, srcValue, flagsVal }; 1608 CGF.EmitNounwindRuntimeCall(fn, args); 1609 } 1610 1611 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1612 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0)); 1613 llvm::Value *value = CGF.Builder.CreateLoad(field); 1614 1615 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER); 1616 } 1617 1618 void profileImpl(llvm::FoldingSetNodeID &id) const { 1619 id.AddInteger(Flags.getBitMask()); 1620 } 1621}; 1622 1623/// Emits the copy/dispose helpers for an ARC __block __weak variable. 1624class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers { 1625public: 1626 ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1627 1628 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1629 llvm::Value *srcField) { 1630 CGF.EmitARCMoveWeak(destField, srcField); 1631 } 1632 1633 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1634 CGF.EmitARCDestroyWeak(field); 1635 } 1636 1637 void profileImpl(llvm::FoldingSetNodeID &id) const { 1638 // 0 is distinguishable from all pointers and byref flags 1639 id.AddInteger(0); 1640 } 1641}; 1642 1643/// Emits the copy/dispose helpers for an ARC __block __strong variable 1644/// that's not of block-pointer type. 1645class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers { 1646public: 1647 ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1648 1649 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1650 llvm::Value *srcField) { 1651 // Do a "move" by copying the value and then zeroing out the old 1652 // variable. 1653 1654 llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField); 1655 value->setAlignment(Alignment.getQuantity()); 1656 1657 llvm::Value *null = 1658 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType())); 1659 1660 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) { 1661 llvm::StoreInst *store = CGF.Builder.CreateStore(null, destField); 1662 store->setAlignment(Alignment.getQuantity()); 1663 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true); 1664 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true); 1665 return; 1666 } 1667 llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField); 1668 store->setAlignment(Alignment.getQuantity()); 1669 1670 store = CGF.Builder.CreateStore(null, srcField); 1671 store->setAlignment(Alignment.getQuantity()); 1672 } 1673 1674 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1675 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1676 } 1677 1678 void profileImpl(llvm::FoldingSetNodeID &id) const { 1679 // 1 is distinguishable from all pointers and byref flags 1680 id.AddInteger(1); 1681 } 1682}; 1683 1684/// Emits the copy/dispose helpers for an ARC __block __strong 1685/// variable that's of block-pointer type. 1686class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers { 1687public: 1688 ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1689 1690 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1691 llvm::Value *srcField) { 1692 // Do the copy with objc_retainBlock; that's all that 1693 // _Block_object_assign would do anyway, and we'd have to pass the 1694 // right arguments to make sure it doesn't get no-op'ed. 1695 llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField); 1696 oldValue->setAlignment(Alignment.getQuantity()); 1697 1698 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true); 1699 1700 llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField); 1701 store->setAlignment(Alignment.getQuantity()); 1702 } 1703 1704 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1705 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1706 } 1707 1708 void profileImpl(llvm::FoldingSetNodeID &id) const { 1709 // 2 is distinguishable from all pointers and byref flags 1710 id.AddInteger(2); 1711 } 1712}; 1713 1714/// Emits the copy/dispose helpers for a __block variable with a 1715/// nontrivial copy constructor or destructor. 1716class CXXByrefHelpers : public CodeGenModule::ByrefHelpers { 1717 QualType VarType; 1718 const Expr *CopyExpr; 1719 1720public: 1721 CXXByrefHelpers(CharUnits alignment, QualType type, 1722 const Expr *copyExpr) 1723 : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {} 1724 1725 bool needsCopy() const { return CopyExpr != 0; } 1726 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1727 llvm::Value *srcField) { 1728 if (!CopyExpr) return; 1729 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr); 1730 } 1731 1732 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1733 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin(); 1734 CGF.PushDestructorCleanup(VarType, field); 1735 CGF.PopCleanupBlocks(cleanupDepth); 1736 } 1737 1738 void profileImpl(llvm::FoldingSetNodeID &id) const { 1739 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr()); 1740 } 1741}; 1742} // end anonymous namespace 1743 1744static llvm::Constant * 1745generateByrefCopyHelper(CodeGenFunction &CGF, 1746 llvm::StructType &byrefType, 1747 unsigned valueFieldIndex, 1748 CodeGenModule::ByrefHelpers &byrefInfo) { 1749 ASTContext &Context = CGF.getContext(); 1750 1751 QualType R = Context.VoidTy; 1752 1753 FunctionArgList args; 1754 ImplicitParamDecl dst(0, SourceLocation(), 0, Context.VoidPtrTy); 1755 args.push_back(&dst); 1756 1757 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1758 args.push_back(&src); 1759 1760 const CGFunctionInfo &FI = 1761 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1762 FunctionType::ExtInfo(), 1763 /*variadic*/ false); 1764 1765 CodeGenTypes &Types = CGF.CGM.getTypes(); 1766 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1767 1768 // FIXME: We'd like to put these into a mergable by content, with 1769 // internal linkage. 1770 llvm::Function *Fn = 1771 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1772 "__Block_byref_object_copy_", &CGF.CGM.getModule()); 1773 1774 IdentifierInfo *II 1775 = &Context.Idents.get("__Block_byref_object_copy_"); 1776 1777 FunctionDecl *FD = FunctionDecl::Create(Context, 1778 Context.getTranslationUnitDecl(), 1779 SourceLocation(), 1780 SourceLocation(), II, R, 0, 1781 SC_Static, 1782 false, false); 1783 1784 // Initialize debug info if necessary. 1785 CGF.maybeInitializeDebugInfo(); 1786 CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); 1787 1788 if (byrefInfo.needsCopy()) { 1789 llvm::Type *byrefPtrType = byrefType.getPointerTo(0); 1790 1791 // dst->x 1792 llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst); 1793 destField = CGF.Builder.CreateLoad(destField); 1794 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType); 1795 destField = CGF.Builder.CreateStructGEP(destField, valueFieldIndex, "x"); 1796 1797 // src->x 1798 llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src); 1799 srcField = CGF.Builder.CreateLoad(srcField); 1800 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType); 1801 srcField = CGF.Builder.CreateStructGEP(srcField, valueFieldIndex, "x"); 1802 1803 byrefInfo.emitCopy(CGF, destField, srcField); 1804 } 1805 1806 CGF.FinishFunction(); 1807 1808 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1809} 1810 1811/// Build the copy helper for a __block variable. 1812static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM, 1813 llvm::StructType &byrefType, 1814 unsigned byrefValueIndex, 1815 CodeGenModule::ByrefHelpers &info) { 1816 CodeGenFunction CGF(CGM); 1817 return generateByrefCopyHelper(CGF, byrefType, byrefValueIndex, info); 1818} 1819 1820/// Generate code for a __block variable's dispose helper. 1821static llvm::Constant * 1822generateByrefDisposeHelper(CodeGenFunction &CGF, 1823 llvm::StructType &byrefType, 1824 unsigned byrefValueIndex, 1825 CodeGenModule::ByrefHelpers &byrefInfo) { 1826 ASTContext &Context = CGF.getContext(); 1827 QualType R = Context.VoidTy; 1828 1829 FunctionArgList args; 1830 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1831 args.push_back(&src); 1832 1833 const CGFunctionInfo &FI = 1834 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1835 FunctionType::ExtInfo(), 1836 /*variadic*/ false); 1837 1838 CodeGenTypes &Types = CGF.CGM.getTypes(); 1839 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1840 1841 // FIXME: We'd like to put these into a mergable by content, with 1842 // internal linkage. 1843 llvm::Function *Fn = 1844 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1845 "__Block_byref_object_dispose_", 1846 &CGF.CGM.getModule()); 1847 1848 IdentifierInfo *II 1849 = &Context.Idents.get("__Block_byref_object_dispose_"); 1850 1851 FunctionDecl *FD = FunctionDecl::Create(Context, 1852 Context.getTranslationUnitDecl(), 1853 SourceLocation(), 1854 SourceLocation(), II, R, 0, 1855 SC_Static, 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. 1876static 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. 1886template <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. 1916CodeGenModule::ByrefHelpers * 1917CodeGenFunction::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 1992unsigned 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 1998llvm::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/// 2022llvm::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 > 2065 getContext().toCharUnitsFromBits(getTarget().getPointerAlign(0))) { 2066 // We have to insert padding. 2067 2068 // The struct above has 2 32-bit integers. 2069 unsigned CurrentOffsetInBytes = 4 * 2; 2070 2071 // And either 2, 3, 4 or 5 pointers. 2072 unsigned noPointers = 2; 2073 if (HasCopyAndDispose) 2074 noPointers += 2; 2075 if (HasByrefExtendedLayout) 2076 noPointers += 1; 2077 2078 CurrentOffsetInBytes += noPointers * CGM.getDataLayout().getTypeAllocSize(Int8PtrTy); 2079 2080 // Align the offset. 2081 unsigned AlignedOffsetInBytes = 2082 llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity()); 2083 2084 unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes; 2085 if (NumPaddingBytes > 0) { 2086 llvm::Type *Ty = Int8Ty; 2087 // FIXME: We need a sema error for alignment larger than the minimum of 2088 // the maximal stack alignment and the alignment of malloc on the system. 2089 if (NumPaddingBytes > 1) 2090 Ty = llvm::ArrayType::get(Ty, NumPaddingBytes); 2091 2092 types.push_back(Ty); 2093 2094 // We want a packed struct. 2095 Packed = true; 2096 } 2097 } 2098 2099 // T x; 2100 types.push_back(ConvertTypeForMem(Ty)); 2101 2102 ByRefType->setBody(types, Packed); 2103 2104 Info.first = ByRefType; 2105 2106 Info.second = types.size() - 1; 2107 2108 return Info.first; 2109} 2110 2111/// Initialize the structural components of a __block variable, i.e. 2112/// everything but the actual object. 2113void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) { 2114 // Find the address of the local. 2115 llvm::Value *addr = emission.Address; 2116 2117 // That's an alloca of the byref structure type. 2118 llvm::StructType *byrefType = cast<llvm::StructType>( 2119 cast<llvm::PointerType>(addr->getType())->getElementType()); 2120 2121 // Build the byref helpers if necessary. This is null if we don't need any. 2122 CodeGenModule::ByrefHelpers *helpers = 2123 buildByrefHelpers(*byrefType, emission); 2124 2125 const VarDecl &D = *emission.Variable; 2126 QualType type = D.getType(); 2127 2128 bool HasByrefExtendedLayout; 2129 Qualifiers::ObjCLifetime ByrefLifetime; 2130 bool ByRefHasLifetime = 2131 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout); 2132 2133 llvm::Value *V; 2134 2135 // Initialize the 'isa', which is just 0 or 1. 2136 int isa = 0; 2137 if (type.isObjCGCWeak()) 2138 isa = 1; 2139 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa"); 2140 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 0, "byref.isa")); 2141 2142 // Store the address of the variable into its own forwarding pointer. 2143 Builder.CreateStore(addr, 2144 Builder.CreateStructGEP(addr, 1, "byref.forwarding")); 2145 2146 // Blocks ABI: 2147 // c) the flags field is set to either 0 if no helper functions are 2148 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are, 2149 BlockFlags flags; 2150 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE; 2151 if (ByRefHasLifetime) { 2152 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED; 2153 else switch (ByrefLifetime) { 2154 case Qualifiers::OCL_Strong: 2155 flags |= BLOCK_BYREF_LAYOUT_STRONG; 2156 break; 2157 case Qualifiers::OCL_Weak: 2158 flags |= BLOCK_BYREF_LAYOUT_WEAK; 2159 break; 2160 case Qualifiers::OCL_ExplicitNone: 2161 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED; 2162 break; 2163 case Qualifiers::OCL_None: 2164 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType()) 2165 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT; 2166 break; 2167 default: 2168 break; 2169 } 2170 if (CGM.getLangOpts().ObjCGCBitmapPrint) { 2171 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask()); 2172 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE) 2173 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE"); 2174 if (flags & BLOCK_BYREF_LAYOUT_MASK) { 2175 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK); 2176 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED) 2177 printf(" BLOCK_BYREF_LAYOUT_EXTENDED"); 2178 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG) 2179 printf(" BLOCK_BYREF_LAYOUT_STRONG"); 2180 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK) 2181 printf(" BLOCK_BYREF_LAYOUT_WEAK"); 2182 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED) 2183 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED"); 2184 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT) 2185 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT"); 2186 } 2187 printf("\n"); 2188 } 2189 } 2190 2191 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 2192 Builder.CreateStructGEP(addr, 2, "byref.flags")); 2193 2194 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType); 2195 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity()); 2196 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 3, "byref.size")); 2197 2198 if (helpers) { 2199 llvm::Value *copy_helper = Builder.CreateStructGEP(addr, 4); 2200 Builder.CreateStore(helpers->CopyHelper, copy_helper); 2201 2202 llvm::Value *destroy_helper = Builder.CreateStructGEP(addr, 5); 2203 Builder.CreateStore(helpers->DisposeHelper, destroy_helper); 2204 } 2205 if (ByRefHasLifetime && HasByrefExtendedLayout) { 2206 llvm::Constant* ByrefLayoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type); 2207 llvm::Value *ByrefInfoAddr = Builder.CreateStructGEP(addr, helpers ? 6 : 4, 2208 "byref.layout"); 2209 // cast destination to pointer to source type. 2210 llvm::Type *DesTy = ByrefLayoutInfo->getType(); 2211 DesTy = DesTy->getPointerTo(); 2212 llvm::Value *BC = Builder.CreatePointerCast(ByrefInfoAddr, DesTy); 2213 Builder.CreateStore(ByrefLayoutInfo, BC); 2214 } 2215} 2216 2217void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) { 2218 llvm::Value *F = CGM.getBlockObjectDispose(); 2219 llvm::Value *args[] = { 2220 Builder.CreateBitCast(V, Int8PtrTy), 2221 llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 2222 }; 2223 EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors? 2224} 2225 2226namespace { 2227 struct CallBlockRelease : EHScopeStack::Cleanup { 2228 llvm::Value *Addr; 2229 CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {} 2230 2231 void Emit(CodeGenFunction &CGF, Flags flags) { 2232 // Should we be passing FIELD_IS_WEAK here? 2233 CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF); 2234 } 2235 }; 2236} 2237 2238/// Enter a cleanup to destroy a __block variable. Note that this 2239/// cleanup should be a no-op if the variable hasn't left the stack 2240/// yet; if a cleanup is required for the variable itself, that needs 2241/// to be done externally. 2242void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) { 2243 // We don't enter this cleanup if we're in pure-GC mode. 2244 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) 2245 return; 2246 2247 EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address); 2248} 2249 2250/// Adjust the declaration of something from the blocks API. 2251static void configureBlocksRuntimeObject(CodeGenModule &CGM, 2252 llvm::Constant *C) { 2253 if (!CGM.getLangOpts().BlocksRuntimeOptional) return; 2254 2255 llvm::GlobalValue *GV = cast<llvm::GlobalValue>(C->stripPointerCasts()); 2256 if (GV->isDeclaration() && 2257 GV->getLinkage() == llvm::GlobalValue::ExternalLinkage) 2258 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 2259} 2260 2261llvm::Constant *CodeGenModule::getBlockObjectDispose() { 2262 if (BlockObjectDispose) 2263 return BlockObjectDispose; 2264 2265 llvm::Type *args[] = { Int8PtrTy, Int32Ty }; 2266 llvm::FunctionType *fty 2267 = llvm::FunctionType::get(VoidTy, args, false); 2268 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose"); 2269 configureBlocksRuntimeObject(*this, BlockObjectDispose); 2270 return BlockObjectDispose; 2271} 2272 2273llvm::Constant *CodeGenModule::getBlockObjectAssign() { 2274 if (BlockObjectAssign) 2275 return BlockObjectAssign; 2276 2277 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty }; 2278 llvm::FunctionType *fty 2279 = llvm::FunctionType::get(VoidTy, args, false); 2280 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign"); 2281 configureBlocksRuntimeObject(*this, BlockObjectAssign); 2282 return BlockObjectAssign; 2283} 2284 2285llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { 2286 if (NSConcreteGlobalBlock) 2287 return NSConcreteGlobalBlock; 2288 2289 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock", 2290 Int8PtrTy->getPointerTo(), 0); 2291 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock); 2292 return NSConcreteGlobalBlock; 2293} 2294 2295llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { 2296 if (NSConcreteStackBlock) 2297 return NSConcreteStackBlock; 2298 2299 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock", 2300 Int8PtrTy->getPointerTo(), 0); 2301 configureBlocksRuntimeObject(*this, NSConcreteStackBlock); 2302 return NSConcreteStackBlock; 2303} 2304