CGBlocks.cpp revision 263508
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/// \code 67/// struct Block_descriptor { 68/// unsigned long reserved; 69/// unsigned long size; // size of Block_literal metadata in bytes. 70/// void *copy_func_helper_decl; // optional copy helper. 71/// void *destroy_func_decl; // optioanl destructor helper. 72/// void *block_method_encoding_address; // @encode for block literal signature. 73/// void *block_layout_info; // encoding of captured block variables. 74/// }; 75/// \endcode 76static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM, 77 const CGBlockInfo &blockInfo) { 78 ASTContext &C = CGM.getContext(); 79 80 llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy); 81 llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 82 83 SmallVector<llvm::Constant*, 6> elements; 84 85 // reserved 86 elements.push_back(llvm::ConstantInt::get(ulong, 0)); 87 88 // Size 89 // FIXME: What is the right way to say this doesn't fit? We should give 90 // a user diagnostic in that case. Better fix would be to change the 91 // API to size_t. 92 elements.push_back(llvm::ConstantInt::get(ulong, 93 blockInfo.BlockSize.getQuantity())); 94 95 // Optional copy/dispose helpers. 96 if (blockInfo.NeedsCopyDispose) { 97 // copy_func_helper_decl 98 elements.push_back(buildCopyHelper(CGM, blockInfo)); 99 100 // destroy_func_decl 101 elements.push_back(buildDisposeHelper(CGM, blockInfo)); 102 } 103 104 // Signature. Mandatory ObjC-style method descriptor @encode sequence. 105 std::string typeAtEncoding = 106 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr()); 107 elements.push_back(llvm::ConstantExpr::getBitCast( 108 CGM.GetAddrOfConstantCString(typeAtEncoding), i8p)); 109 110 // GC layout. 111 if (C.getLangOpts().ObjC1) { 112 if (CGM.getLangOpts().getGC() != LangOptions::NonGC) 113 elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo)); 114 else 115 elements.push_back(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo)); 116 } 117 else 118 elements.push_back(llvm::Constant::getNullValue(i8p)); 119 120 llvm::Constant *init = llvm::ConstantStruct::getAnon(elements); 121 122 llvm::GlobalVariable *global = 123 new llvm::GlobalVariable(CGM.getModule(), init->getType(), true, 124 llvm::GlobalValue::InternalLinkage, 125 init, "__block_descriptor_tmp"); 126 127 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType()); 128} 129 130/* 131 Purely notional variadic template describing the layout of a block. 132 133 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes> 134 struct Block_literal { 135 /// Initialized to one of: 136 /// extern void *_NSConcreteStackBlock[]; 137 /// extern void *_NSConcreteGlobalBlock[]; 138 /// 139 /// In theory, we could start one off malloc'ed by setting 140 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using 141 /// this isa: 142 /// extern void *_NSConcreteMallocBlock[]; 143 struct objc_class *isa; 144 145 /// These are the flags (with corresponding bit number) that the 146 /// compiler is actually supposed to know about. 147 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block 148 /// descriptor provides copy and dispose helper functions 149 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured 150 /// object with a nontrivial destructor or copy constructor 151 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated 152 /// as global memory 153 /// 29. BLOCK_USE_STRET - indicates that the block function 154 /// uses stret, which objc_msgSend needs to know about 155 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an 156 /// @encoded signature string 157 /// And we're not supposed to manipulate these: 158 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved 159 /// to malloc'ed memory 160 /// 27. BLOCK_IS_GC - indicates that the block has been moved to 161 /// to GC-allocated memory 162 /// Additionally, the bottom 16 bits are a reference count which 163 /// should be zero on the stack. 164 int flags; 165 166 /// Reserved; should be zero-initialized. 167 int reserved; 168 169 /// Function pointer generated from block literal. 170 _ResultType (*invoke)(Block_literal *, _ParamTypes...); 171 172 /// Block description metadata generated from block literal. 173 struct Block_descriptor *block_descriptor; 174 175 /// Captured values follow. 176 _CapturesTypes captures...; 177 }; 178 */ 179 180/// The number of fields in a block header. 181const unsigned BlockHeaderSize = 5; 182 183namespace { 184 /// A chunk of data that we actually have to capture in the block. 185 struct BlockLayoutChunk { 186 CharUnits Alignment; 187 CharUnits Size; 188 Qualifiers::ObjCLifetime Lifetime; 189 const BlockDecl::Capture *Capture; // null for 'this' 190 llvm::Type *Type; 191 192 BlockLayoutChunk(CharUnits align, CharUnits size, 193 Qualifiers::ObjCLifetime lifetime, 194 const BlockDecl::Capture *capture, 195 llvm::Type *type) 196 : Alignment(align), Size(size), Lifetime(lifetime), 197 Capture(capture), Type(type) {} 198 199 /// Tell the block info that this chunk has the given field index. 200 void setIndex(CGBlockInfo &info, unsigned index) { 201 if (!Capture) 202 info.CXXThisIndex = index; 203 else 204 info.Captures[Capture->getVariable()] 205 = CGBlockInfo::Capture::makeIndex(index); 206 } 207 }; 208 209 /// Order by 1) all __strong together 2) next, all byfref together 3) next, 210 /// all __weak together. Preserve descending alignment in all situations. 211 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) { 212 CharUnits LeftValue, RightValue; 213 bool LeftByref = left.Capture ? left.Capture->isByRef() : false; 214 bool RightByref = right.Capture ? right.Capture->isByRef() : false; 215 216 if (left.Lifetime == Qualifiers::OCL_Strong && 217 left.Alignment >= right.Alignment) 218 LeftValue = CharUnits::fromQuantity(64); 219 else if (LeftByref && left.Alignment >= right.Alignment) 220 LeftValue = CharUnits::fromQuantity(32); 221 else if (left.Lifetime == Qualifiers::OCL_Weak && 222 left.Alignment >= right.Alignment) 223 LeftValue = CharUnits::fromQuantity(16); 224 else 225 LeftValue = left.Alignment; 226 if (right.Lifetime == Qualifiers::OCL_Strong && 227 right.Alignment >= left.Alignment) 228 RightValue = CharUnits::fromQuantity(64); 229 else if (RightByref && right.Alignment >= left.Alignment) 230 RightValue = CharUnits::fromQuantity(32); 231 else if (right.Lifetime == Qualifiers::OCL_Weak && 232 right.Alignment >= left.Alignment) 233 RightValue = CharUnits::fromQuantity(16); 234 else 235 RightValue = right.Alignment; 236 237 return LeftValue > RightValue; 238 } 239} 240 241/// Determines if the given type is safe for constant capture in C++. 242static bool isSafeForCXXConstantCapture(QualType type) { 243 const RecordType *recordType = 244 type->getBaseElementTypeUnsafe()->getAs<RecordType>(); 245 246 // Only records can be unsafe. 247 if (!recordType) return true; 248 249 const CXXRecordDecl *record = cast<CXXRecordDecl>(recordType->getDecl()); 250 251 // Maintain semantics for classes with non-trivial dtors or copy ctors. 252 if (!record->hasTrivialDestructor()) return false; 253 if (record->hasNonTrivialCopyConstructor()) return false; 254 255 // Otherwise, we just have to make sure there aren't any mutable 256 // fields that might have changed since initialization. 257 return !record->hasMutableFields(); 258} 259 260/// It is illegal to modify a const object after initialization. 261/// Therefore, if a const object has a constant initializer, we don't 262/// actually need to keep storage for it in the block; we'll just 263/// rematerialize it at the start of the block function. This is 264/// acceptable because we make no promises about address stability of 265/// captured variables. 266static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM, 267 CodeGenFunction *CGF, 268 const VarDecl *var) { 269 QualType type = var->getType(); 270 271 // We can only do this if the variable is const. 272 if (!type.isConstQualified()) return 0; 273 274 // Furthermore, in C++ we have to worry about mutable fields: 275 // C++ [dcl.type.cv]p4: 276 // Except that any class member declared mutable can be 277 // modified, any attempt to modify a const object during its 278 // lifetime results in undefined behavior. 279 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type)) 280 return 0; 281 282 // If the variable doesn't have any initializer (shouldn't this be 283 // invalid?), it's not clear what we should do. Maybe capture as 284 // zero? 285 const Expr *init = var->getInit(); 286 if (!init) return 0; 287 288 return CGM.EmitConstantInit(*var, CGF); 289} 290 291/// Get the low bit of a nonzero character count. This is the 292/// alignment of the nth byte if the 0th byte is universally aligned. 293static CharUnits getLowBit(CharUnits v) { 294 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1)); 295} 296 297static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, 298 SmallVectorImpl<llvm::Type*> &elementTypes) { 299 ASTContext &C = CGM.getContext(); 300 301 // The header is basically a 'struct { void *; int; int; void *; void *; }'. 302 CharUnits ptrSize, ptrAlign, intSize, intAlign; 303 llvm::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.VoidPtrTy); 304 llvm::tie(intSize, intAlign) = C.getTypeInfoInChars(C.IntTy); 305 306 // Are there crazy embedded platforms where this isn't true? 307 assert(intSize <= ptrSize && "layout assumptions horribly violated"); 308 309 CharUnits headerSize = ptrSize; 310 if (2 * intSize < ptrAlign) headerSize += ptrSize; 311 else headerSize += 2 * intSize; 312 headerSize += 2 * ptrSize; 313 314 info.BlockAlign = ptrAlign; 315 info.BlockSize = headerSize; 316 317 assert(elementTypes.empty()); 318 llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); 319 llvm::Type *intTy = CGM.getTypes().ConvertType(C.IntTy); 320 elementTypes.push_back(i8p); 321 elementTypes.push_back(intTy); 322 elementTypes.push_back(intTy); 323 elementTypes.push_back(i8p); 324 elementTypes.push_back(CGM.getBlockDescriptorType()); 325 326 assert(elementTypes.size() == BlockHeaderSize); 327} 328 329/// Compute the layout of the given block. Attempts to lay the block 330/// out with minimal space requirements. 331static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, 332 CGBlockInfo &info) { 333 ASTContext &C = CGM.getContext(); 334 const BlockDecl *block = info.getBlockDecl(); 335 336 SmallVector<llvm::Type*, 8> elementTypes; 337 initializeForBlockHeader(CGM, info, elementTypes); 338 339 if (!block->hasCaptures()) { 340 info.StructureType = 341 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 342 info.CanBeGlobal = true; 343 return; 344 } 345 else if (C.getLangOpts().ObjC1 && 346 CGM.getLangOpts().getGC() == LangOptions::NonGC) 347 info.HasCapturedVariableLayout = true; 348 349 // Collect the layout chunks. 350 SmallVector<BlockLayoutChunk, 16> layout; 351 layout.reserve(block->capturesCXXThis() + 352 (block->capture_end() - block->capture_begin())); 353 354 CharUnits maxFieldAlign; 355 356 // First, 'this'. 357 if (block->capturesCXXThis()) { 358 assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && 359 "Can't capture 'this' outside a method"); 360 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C); 361 362 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType); 363 std::pair<CharUnits,CharUnits> tinfo 364 = CGM.getContext().getTypeInfoInChars(thisType); 365 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 366 367 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 368 Qualifiers::OCL_None, 369 0, llvmType)); 370 } 371 372 // Next, all the block captures. 373 for (BlockDecl::capture_const_iterator ci = block->capture_begin(), 374 ce = block->capture_end(); ci != ce; ++ci) { 375 const VarDecl *variable = ci->getVariable(); 376 377 if (ci->isByRef()) { 378 // We have to copy/dispose of the __block reference. 379 info.NeedsCopyDispose = true; 380 381 // Just use void* instead of a pointer to the byref type. 382 QualType byRefPtrTy = C.VoidPtrTy; 383 384 llvm::Type *llvmType = CGM.getTypes().ConvertType(byRefPtrTy); 385 std::pair<CharUnits,CharUnits> tinfo 386 = CGM.getContext().getTypeInfoInChars(byRefPtrTy); 387 maxFieldAlign = std::max(maxFieldAlign, tinfo.second); 388 389 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 390 Qualifiers::OCL_None, 391 &*ci, llvmType)); 392 continue; 393 } 394 395 // Otherwise, build a layout chunk with the size and alignment of 396 // the declaration. 397 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) { 398 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant); 399 continue; 400 } 401 402 // If we have a lifetime qualifier, honor it for capture purposes. 403 // That includes *not* copying it if it's __unsafe_unretained. 404 Qualifiers::ObjCLifetime lifetime = 405 variable->getType().getObjCLifetime(); 406 if (lifetime) { 407 switch (lifetime) { 408 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 409 case Qualifiers::OCL_ExplicitNone: 410 case Qualifiers::OCL_Autoreleasing: 411 break; 412 413 case Qualifiers::OCL_Strong: 414 case Qualifiers::OCL_Weak: 415 info.NeedsCopyDispose = true; 416 } 417 418 // Block pointers require copy/dispose. So do Objective-C pointers. 419 } else if (variable->getType()->isObjCRetainableType()) { 420 info.NeedsCopyDispose = true; 421 // used for mrr below. 422 lifetime = Qualifiers::OCL_Strong; 423 424 // So do types that require non-trivial copy construction. 425 } else if (ci->hasCopyExpr()) { 426 info.NeedsCopyDispose = true; 427 info.HasCXXObject = true; 428 429 // And so do types with destructors. 430 } else if (CGM.getLangOpts().CPlusPlus) { 431 if (const CXXRecordDecl *record = 432 variable->getType()->getAsCXXRecordDecl()) { 433 if (!record->hasTrivialDestructor()) { 434 info.HasCXXObject = true; 435 info.NeedsCopyDispose = true; 436 } 437 } 438 } 439 440 QualType VT = variable->getType(); 441 CharUnits size = C.getTypeSizeInChars(VT); 442 CharUnits align = C.getDeclAlign(variable); 443 444 maxFieldAlign = std::max(maxFieldAlign, align); 445 446 llvm::Type *llvmType = 447 CGM.getTypes().ConvertTypeForMem(VT); 448 449 layout.push_back(BlockLayoutChunk(align, size, lifetime, &*ci, llvmType)); 450 } 451 452 // If that was everything, we're done here. 453 if (layout.empty()) { 454 info.StructureType = 455 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 456 info.CanBeGlobal = true; 457 return; 458 } 459 460 // Sort the layout by alignment. We have to use a stable sort here 461 // to get reproducible results. There should probably be an 462 // llvm::array_pod_stable_sort. 463 std::stable_sort(layout.begin(), layout.end()); 464 465 // Needed for blocks layout info. 466 info.BlockHeaderForcedGapOffset = info.BlockSize; 467 info.BlockHeaderForcedGapSize = CharUnits::Zero(); 468 469 CharUnits &blockSize = info.BlockSize; 470 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign); 471 472 // Assuming that the first byte in the header is maximally aligned, 473 // get the alignment of the first byte following the header. 474 CharUnits endAlign = getLowBit(blockSize); 475 476 // If the end of the header isn't satisfactorily aligned for the 477 // maximum thing, look for things that are okay with the header-end 478 // alignment, and keep appending them until we get something that's 479 // aligned right. This algorithm is only guaranteed optimal if 480 // that condition is satisfied at some point; otherwise we can get 481 // things like: 482 // header // next byte has alignment 4 483 // something_with_size_5; // next byte has alignment 1 484 // something_with_alignment_8; 485 // which has 7 bytes of padding, as opposed to the naive solution 486 // which might have less (?). 487 if (endAlign < maxFieldAlign) { 488 SmallVectorImpl<BlockLayoutChunk>::iterator 489 li = layout.begin() + 1, le = layout.end(); 490 491 // Look for something that the header end is already 492 // satisfactorily aligned for. 493 for (; li != le && endAlign < li->Alignment; ++li) 494 ; 495 496 // If we found something that's naturally aligned for the end of 497 // the header, keep adding things... 498 if (li != le) { 499 SmallVectorImpl<BlockLayoutChunk>::iterator first = li; 500 for (; li != le; ++li) { 501 assert(endAlign >= li->Alignment); 502 503 li->setIndex(info, elementTypes.size()); 504 elementTypes.push_back(li->Type); 505 blockSize += li->Size; 506 endAlign = getLowBit(blockSize); 507 508 // ...until we get to the alignment of the maximum field. 509 if (endAlign >= maxFieldAlign) { 510 if (li == first) { 511 // No user field was appended. So, a gap was added. 512 // Save total gap size for use in block layout bit map. 513 info.BlockHeaderForcedGapSize = li->Size; 514 } 515 break; 516 } 517 } 518 // Don't re-append everything we just appended. 519 layout.erase(first, li); 520 } 521 } 522 523 assert(endAlign == getLowBit(blockSize)); 524 525 // At this point, we just have to add padding if the end align still 526 // isn't aligned right. 527 if (endAlign < maxFieldAlign) { 528 CharUnits newBlockSize = blockSize.RoundUpToAlignment(maxFieldAlign); 529 CharUnits padding = newBlockSize - blockSize; 530 531 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty, 532 padding.getQuantity())); 533 blockSize = newBlockSize; 534 endAlign = getLowBit(blockSize); // might be > maxFieldAlign 535 } 536 537 assert(endAlign >= maxFieldAlign); 538 assert(endAlign == getLowBit(blockSize)); 539 // Slam everything else on now. This works because they have 540 // strictly decreasing alignment and we expect that size is always a 541 // multiple of alignment. 542 for (SmallVectorImpl<BlockLayoutChunk>::iterator 543 li = layout.begin(), le = layout.end(); li != le; ++li) { 544 assert(endAlign >= li->Alignment); 545 li->setIndex(info, elementTypes.size()); 546 elementTypes.push_back(li->Type); 547 blockSize += li->Size; 548 endAlign = getLowBit(blockSize); 549 } 550 551 info.StructureType = 552 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); 553} 554 555/// Enter the scope of a block. This should be run at the entrance to 556/// a full-expression so that the block's cleanups are pushed at the 557/// right place in the stack. 558static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) { 559 assert(CGF.HaveInsertPoint()); 560 561 // Allocate the block info and place it at the head of the list. 562 CGBlockInfo &blockInfo = 563 *new CGBlockInfo(block, CGF.CurFn->getName()); 564 blockInfo.NextBlockInfo = CGF.FirstBlockInfo; 565 CGF.FirstBlockInfo = &blockInfo; 566 567 // Compute information about the layout, etc., of this block, 568 // pushing cleanups as necessary. 569 computeBlockInfo(CGF.CGM, &CGF, blockInfo); 570 571 // Nothing else to do if it can be global. 572 if (blockInfo.CanBeGlobal) return; 573 574 // Make the allocation for the block. 575 blockInfo.Address = 576 CGF.CreateTempAlloca(blockInfo.StructureType, "block"); 577 blockInfo.Address->setAlignment(blockInfo.BlockAlign.getQuantity()); 578 579 // If there are cleanups to emit, enter them (but inactive). 580 if (!blockInfo.NeedsCopyDispose) return; 581 582 // Walk through the captures (in order) and find the ones not 583 // captured by constant. 584 for (BlockDecl::capture_const_iterator ci = block->capture_begin(), 585 ce = block->capture_end(); ci != ce; ++ci) { 586 // Ignore __block captures; there's nothing special in the 587 // on-stack block that we need to do for them. 588 if (ci->isByRef()) continue; 589 590 // Ignore variables that are constant-captured. 591 const VarDecl *variable = ci->getVariable(); 592 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 593 if (capture.isConstant()) continue; 594 595 // Ignore objects that aren't destructed. 596 QualType::DestructionKind dtorKind = 597 variable->getType().isDestructedType(); 598 if (dtorKind == QualType::DK_none) continue; 599 600 CodeGenFunction::Destroyer *destroyer; 601 602 // Block captures count as local values and have imprecise semantics. 603 // They also can't be arrays, so need to worry about that. 604 if (dtorKind == QualType::DK_objc_strong_lifetime) { 605 destroyer = CodeGenFunction::destroyARCStrongImprecise; 606 } else { 607 destroyer = CGF.getDestroyer(dtorKind); 608 } 609 610 // GEP down to the address. 611 llvm::Value *addr = CGF.Builder.CreateStructGEP(blockInfo.Address, 612 capture.getIndex()); 613 614 // We can use that GEP as the dominating IP. 615 if (!blockInfo.DominatingIP) 616 blockInfo.DominatingIP = cast<llvm::Instruction>(addr); 617 618 CleanupKind cleanupKind = InactiveNormalCleanup; 619 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind); 620 if (useArrayEHCleanup) 621 cleanupKind = InactiveNormalAndEHCleanup; 622 623 CGF.pushDestroy(cleanupKind, addr, variable->getType(), 624 destroyer, useArrayEHCleanup); 625 626 // Remember where that cleanup was. 627 capture.setCleanup(CGF.EHStack.stable_begin()); 628 } 629} 630 631/// Enter a full-expression with a non-trivial number of objects to 632/// clean up. This is in this file because, at the moment, the only 633/// kind of cleanup object is a BlockDecl*. 634void CodeGenFunction::enterNonTrivialFullExpression(const ExprWithCleanups *E) { 635 assert(E->getNumObjects() != 0); 636 ArrayRef<ExprWithCleanups::CleanupObject> cleanups = E->getObjects(); 637 for (ArrayRef<ExprWithCleanups::CleanupObject>::iterator 638 i = cleanups.begin(), e = cleanups.end(); i != e; ++i) { 639 enterBlockScope(*this, *i); 640 } 641} 642 643/// Find the layout for the given block in a linked list and remove it. 644static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head, 645 const BlockDecl *block) { 646 while (true) { 647 assert(head && *head); 648 CGBlockInfo *cur = *head; 649 650 // If this is the block we're looking for, splice it out of the list. 651 if (cur->getBlockDecl() == block) { 652 *head = cur->NextBlockInfo; 653 return cur; 654 } 655 656 head = &cur->NextBlockInfo; 657 } 658} 659 660/// Destroy a chain of block layouts. 661void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) { 662 assert(head && "destroying an empty chain"); 663 do { 664 CGBlockInfo *cur = head; 665 head = cur->NextBlockInfo; 666 delete cur; 667 } while (head != 0); 668} 669 670/// Emit a block literal expression in the current function. 671llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) { 672 // If the block has no captures, we won't have a pre-computed 673 // layout for it. 674 if (!blockExpr->getBlockDecl()->hasCaptures()) { 675 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName()); 676 computeBlockInfo(CGM, this, blockInfo); 677 blockInfo.BlockExpression = blockExpr; 678 return EmitBlockLiteral(blockInfo); 679 } 680 681 // Find the block info for this block and take ownership of it. 682 OwningPtr<CGBlockInfo> blockInfo; 683 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo, 684 blockExpr->getBlockDecl())); 685 686 blockInfo->BlockExpression = blockExpr; 687 return EmitBlockLiteral(*blockInfo); 688} 689 690llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) { 691 // Using the computed layout, generate the actual block function. 692 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda(); 693 llvm::Constant *blockFn 694 = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo, 695 LocalDeclMap, 696 isLambdaConv); 697 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); 698 699 // If there is nothing to capture, we can emit this as a global block. 700 if (blockInfo.CanBeGlobal) 701 return buildGlobalBlock(CGM, blockInfo, blockFn); 702 703 // Otherwise, we have to emit this as a local block. 704 705 llvm::Constant *isa = CGM.getNSConcreteStackBlock(); 706 isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy); 707 708 // Build the block descriptor. 709 llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo); 710 711 llvm::AllocaInst *blockAddr = blockInfo.Address; 712 assert(blockAddr && "block has no address!"); 713 714 // Compute the initial on-stack block flags. 715 BlockFlags flags = BLOCK_HAS_SIGNATURE; 716 if (blockInfo.HasCapturedVariableLayout) flags |= BLOCK_HAS_EXTENDED_LAYOUT; 717 if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE; 718 if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ; 719 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; 720 721 // Initialize the block literal. 722 Builder.CreateStore(isa, Builder.CreateStructGEP(blockAddr, 0, "block.isa")); 723 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 724 Builder.CreateStructGEP(blockAddr, 1, "block.flags")); 725 Builder.CreateStore(llvm::ConstantInt::get(IntTy, 0), 726 Builder.CreateStructGEP(blockAddr, 2, "block.reserved")); 727 Builder.CreateStore(blockFn, Builder.CreateStructGEP(blockAddr, 3, 728 "block.invoke")); 729 Builder.CreateStore(descriptor, Builder.CreateStructGEP(blockAddr, 4, 730 "block.descriptor")); 731 732 // Finally, capture all the values into the block. 733 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 734 735 // First, 'this'. 736 if (blockDecl->capturesCXXThis()) { 737 llvm::Value *addr = Builder.CreateStructGEP(blockAddr, 738 blockInfo.CXXThisIndex, 739 "block.captured-this.addr"); 740 Builder.CreateStore(LoadCXXThis(), addr); 741 } 742 743 // Next, captured variables. 744 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 745 ce = blockDecl->capture_end(); ci != ce; ++ci) { 746 const VarDecl *variable = ci->getVariable(); 747 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 748 749 // Ignore constant captures. 750 if (capture.isConstant()) continue; 751 752 QualType type = variable->getType(); 753 CharUnits align = getContext().getDeclAlign(variable); 754 755 // This will be a [[type]]*, except that a byref entry will just be 756 // an i8**. 757 llvm::Value *blockField = 758 Builder.CreateStructGEP(blockAddr, capture.getIndex(), 759 "block.captured"); 760 761 // Compute the address of the thing we're going to move into the 762 // block literal. 763 llvm::Value *src; 764 if (BlockInfo && ci->isNested()) { 765 // We need to use the capture from the enclosing block. 766 const CGBlockInfo::Capture &enclosingCapture = 767 BlockInfo->getCapture(variable); 768 769 // This is a [[type]]*, except that a byref entry wil just be an i8**. 770 src = Builder.CreateStructGEP(LoadBlockStruct(), 771 enclosingCapture.getIndex(), 772 "block.capture.addr"); 773 } else if (blockDecl->isConversionFromLambda()) { 774 // The lambda capture in a lambda's conversion-to-block-pointer is 775 // special; we'll simply emit it directly. 776 src = 0; 777 } else { 778 // Just look it up in the locals map, which will give us back a 779 // [[type]]*. If that doesn't work, do the more elaborate DRE 780 // emission. 781 src = LocalDeclMap.lookup(variable); 782 if (!src) { 783 DeclRefExpr declRef(const_cast<VarDecl*>(variable), 784 /*refersToEnclosing*/ ci->isNested(), type, 785 VK_LValue, SourceLocation()); 786 src = EmitDeclRefLValue(&declRef).getAddress(); 787 } 788 } 789 790 // For byrefs, we just write the pointer to the byref struct into 791 // the block field. There's no need to chase the forwarding 792 // pointer at this point, since we're building something that will 793 // live a shorter life than the stack byref anyway. 794 if (ci->isByRef()) { 795 // Get a void* that points to the byref struct. 796 if (ci->isNested()) 797 src = Builder.CreateAlignedLoad(src, align.getQuantity(), 798 "byref.capture"); 799 else 800 src = Builder.CreateBitCast(src, VoidPtrTy); 801 802 // Write that void* into the capture field. 803 Builder.CreateAlignedStore(src, blockField, align.getQuantity()); 804 805 // If we have a copy constructor, evaluate that into the block field. 806 } else if (const Expr *copyExpr = ci->getCopyExpr()) { 807 if (blockDecl->isConversionFromLambda()) { 808 // If we have a lambda conversion, emit the expression 809 // directly into the block instead. 810 AggValueSlot Slot = 811 AggValueSlot::forAddr(blockField, align, Qualifiers(), 812 AggValueSlot::IsDestructed, 813 AggValueSlot::DoesNotNeedGCBarriers, 814 AggValueSlot::IsNotAliased); 815 EmitAggExpr(copyExpr, Slot); 816 } else { 817 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr); 818 } 819 820 // If it's a reference variable, copy the reference into the block field. 821 } else if (type->isReferenceType()) { 822 llvm::Value *ref = 823 Builder.CreateAlignedLoad(src, align.getQuantity(), "ref.val"); 824 Builder.CreateAlignedStore(ref, blockField, align.getQuantity()); 825 826 // If this is an ARC __strong block-pointer variable, don't do a 827 // block copy. 828 // 829 // TODO: this can be generalized into the normal initialization logic: 830 // we should never need to do a block-copy when initializing a local 831 // variable, because the local variable's lifetime should be strictly 832 // contained within the stack block's. 833 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong && 834 type->isBlockPointerType()) { 835 // Load the block and do a simple retain. 836 LValue srcLV = MakeAddrLValue(src, type, align); 837 llvm::Value *value = EmitLoadOfScalar(srcLV, SourceLocation()); 838 value = EmitARCRetainNonBlock(value); 839 840 // Do a primitive store to the block field. 841 LValue destLV = MakeAddrLValue(blockField, type, align); 842 EmitStoreOfScalar(value, destLV, /*init*/ true); 843 844 // Otherwise, fake up a POD copy into the block field. 845 } else { 846 // Fake up a new variable so that EmitScalarInit doesn't think 847 // we're referring to the variable in its own initializer. 848 ImplicitParamDecl blockFieldPseudoVar(/*DC*/ 0, SourceLocation(), 849 /*name*/ 0, type); 850 851 // We use one of these or the other depending on whether the 852 // reference is nested. 853 DeclRefExpr declRef(const_cast<VarDecl*>(variable), 854 /*refersToEnclosing*/ ci->isNested(), type, 855 VK_LValue, SourceLocation()); 856 857 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue, 858 &declRef, VK_RValue); 859 EmitExprAsInit(&l2r, &blockFieldPseudoVar, 860 MakeAddrLValue(blockField, type, align), 861 /*captured by init*/ false); 862 } 863 864 // Activate the cleanup if layout pushed one. 865 if (!ci->isByRef()) { 866 EHScopeStack::stable_iterator cleanup = capture.getCleanup(); 867 if (cleanup.isValid()) 868 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP); 869 } 870 } 871 872 // Cast to the converted block-pointer type, which happens (somewhat 873 // unfortunately) to be a pointer to function type. 874 llvm::Value *result = 875 Builder.CreateBitCast(blockAddr, 876 ConvertType(blockInfo.getBlockExpr()->getType())); 877 878 return result; 879} 880 881 882llvm::Type *CodeGenModule::getBlockDescriptorType() { 883 if (BlockDescriptorType) 884 return BlockDescriptorType; 885 886 llvm::Type *UnsignedLongTy = 887 getTypes().ConvertType(getContext().UnsignedLongTy); 888 889 // struct __block_descriptor { 890 // unsigned long reserved; 891 // unsigned long block_size; 892 // 893 // // later, the following will be added 894 // 895 // struct { 896 // void (*copyHelper)(); 897 // void (*copyHelper)(); 898 // } helpers; // !!! optional 899 // 900 // const char *signature; // the block signature 901 // const char *layout; // reserved 902 // }; 903 BlockDescriptorType = 904 llvm::StructType::create("struct.__block_descriptor", 905 UnsignedLongTy, UnsignedLongTy, NULL); 906 907 // Now form a pointer to that. 908 BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType); 909 return BlockDescriptorType; 910} 911 912llvm::Type *CodeGenModule::getGenericBlockLiteralType() { 913 if (GenericBlockLiteralType) 914 return GenericBlockLiteralType; 915 916 llvm::Type *BlockDescPtrTy = getBlockDescriptorType(); 917 918 // struct __block_literal_generic { 919 // void *__isa; 920 // int __flags; 921 // int __reserved; 922 // void (*__invoke)(void *); 923 // struct __block_descriptor *__descriptor; 924 // }; 925 GenericBlockLiteralType = 926 llvm::StructType::create("struct.__block_literal_generic", 927 VoidPtrTy, IntTy, IntTy, VoidPtrTy, 928 BlockDescPtrTy, NULL); 929 930 return GenericBlockLiteralType; 931} 932 933 934RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E, 935 ReturnValueSlot ReturnValue) { 936 const BlockPointerType *BPT = 937 E->getCallee()->getType()->getAs<BlockPointerType>(); 938 939 llvm::Value *Callee = EmitScalarExpr(E->getCallee()); 940 941 // Get a pointer to the generic block literal. 942 llvm::Type *BlockLiteralTy = 943 llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType()); 944 945 // Bitcast the callee to a block literal. 946 llvm::Value *BlockLiteral = 947 Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal"); 948 949 // Get the function pointer from the literal. 950 llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3); 951 952 BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy); 953 954 // Add the block literal. 955 CallArgList Args; 956 Args.add(RValue::get(BlockLiteral), getContext().VoidPtrTy); 957 958 QualType FnType = BPT->getPointeeType(); 959 960 // And the rest of the arguments. 961 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), 962 E->arg_begin(), E->arg_end()); 963 964 // Load the function. 965 llvm::Value *Func = Builder.CreateLoad(FuncPtr); 966 967 const FunctionType *FuncTy = FnType->castAs<FunctionType>(); 968 const CGFunctionInfo &FnInfo = 969 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy); 970 971 // Cast the function pointer to the right type. 972 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo); 973 974 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy); 975 Func = Builder.CreateBitCast(Func, BlockFTyPtr); 976 977 // And call the block. 978 return EmitCall(FnInfo, Func, ReturnValue, Args); 979} 980 981llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable, 982 bool isByRef) { 983 assert(BlockInfo && "evaluating block ref without block information?"); 984 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable); 985 986 // Handle constant captures. 987 if (capture.isConstant()) return LocalDeclMap[variable]; 988 989 llvm::Value *addr = 990 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(), 991 "block.capture.addr"); 992 993 if (isByRef) { 994 // addr should be a void** right now. Load, then cast the result 995 // to byref*. 996 997 addr = Builder.CreateLoad(addr); 998 llvm::PointerType *byrefPointerType 999 = llvm::PointerType::get(BuildByRefType(variable), 0); 1000 addr = Builder.CreateBitCast(addr, byrefPointerType, 1001 "byref.addr"); 1002 1003 // Follow the forwarding pointer. 1004 addr = Builder.CreateStructGEP(addr, 1, "byref.forwarding"); 1005 addr = Builder.CreateLoad(addr, "byref.addr.forwarded"); 1006 1007 // Cast back to byref* and GEP over to the actual object. 1008 addr = Builder.CreateBitCast(addr, byrefPointerType); 1009 addr = Builder.CreateStructGEP(addr, getByRefValueLLVMField(variable), 1010 variable->getNameAsString()); 1011 } 1012 1013 if (variable->getType()->isReferenceType()) 1014 addr = Builder.CreateLoad(addr, "ref.tmp"); 1015 1016 return addr; 1017} 1018 1019llvm::Constant * 1020CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *blockExpr, 1021 const char *name) { 1022 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), name); 1023 blockInfo.BlockExpression = blockExpr; 1024 1025 // Compute information about the layout, etc., of this block. 1026 computeBlockInfo(*this, 0, blockInfo); 1027 1028 // Using that metadata, generate the actual block function. 1029 llvm::Constant *blockFn; 1030 { 1031 llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap; 1032 blockFn = CodeGenFunction(*this).GenerateBlockFunction(GlobalDecl(), 1033 blockInfo, 1034 LocalDeclMap, 1035 false); 1036 } 1037 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); 1038 1039 return buildGlobalBlock(*this, blockInfo, blockFn); 1040} 1041 1042static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, 1043 const CGBlockInfo &blockInfo, 1044 llvm::Constant *blockFn) { 1045 assert(blockInfo.CanBeGlobal); 1046 1047 // Generate the constants for the block literal initializer. 1048 llvm::Constant *fields[BlockHeaderSize]; 1049 1050 // isa 1051 fields[0] = CGM.getNSConcreteGlobalBlock(); 1052 1053 // __flags 1054 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE; 1055 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; 1056 1057 fields[1] = llvm::ConstantInt::get(CGM.IntTy, flags.getBitMask()); 1058 1059 // Reserved 1060 fields[2] = llvm::Constant::getNullValue(CGM.IntTy); 1061 1062 // Function 1063 fields[3] = blockFn; 1064 1065 // Descriptor 1066 fields[4] = buildBlockDescriptor(CGM, blockInfo); 1067 1068 llvm::Constant *init = llvm::ConstantStruct::getAnon(fields); 1069 1070 llvm::GlobalVariable *literal = 1071 new llvm::GlobalVariable(CGM.getModule(), 1072 init->getType(), 1073 /*constant*/ true, 1074 llvm::GlobalVariable::InternalLinkage, 1075 init, 1076 "__block_literal_global"); 1077 literal->setAlignment(blockInfo.BlockAlign.getQuantity()); 1078 1079 // Return a constant of the appropriately-casted type. 1080 llvm::Type *requiredType = 1081 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType()); 1082 return llvm::ConstantExpr::getBitCast(literal, requiredType); 1083} 1084 1085llvm::Function * 1086CodeGenFunction::GenerateBlockFunction(GlobalDecl GD, 1087 const CGBlockInfo &blockInfo, 1088 const DeclMapTy &ldm, 1089 bool IsLambdaConversionToBlock) { 1090 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1091 1092 CurGD = GD; 1093 1094 BlockInfo = &blockInfo; 1095 1096 // Arrange for local static and local extern declarations to appear 1097 // to be local to this function as well, in case they're directly 1098 // referenced in a block. 1099 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) { 1100 const VarDecl *var = dyn_cast<VarDecl>(i->first); 1101 if (var && !var->hasLocalStorage()) 1102 LocalDeclMap[var] = i->second; 1103 } 1104 1105 // Begin building the function declaration. 1106 1107 // Build the argument list. 1108 FunctionArgList args; 1109 1110 // The first argument is the block pointer. Just take it as a void* 1111 // and cast it later. 1112 QualType selfTy = getContext().VoidPtrTy; 1113 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor"); 1114 1115 ImplicitParamDecl selfDecl(const_cast<BlockDecl*>(blockDecl), 1116 SourceLocation(), II, selfTy); 1117 args.push_back(&selfDecl); 1118 1119 // Now add the rest of the parameters. 1120 for (BlockDecl::param_const_iterator i = blockDecl->param_begin(), 1121 e = blockDecl->param_end(); i != e; ++i) 1122 args.push_back(*i); 1123 1124 // Create the function declaration. 1125 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType(); 1126 const CGFunctionInfo &fnInfo = 1127 CGM.getTypes().arrangeFunctionDeclaration(fnType->getResultType(), args, 1128 fnType->getExtInfo(), 1129 fnType->isVariadic()); 1130 if (CGM.ReturnTypeUsesSRet(fnInfo)) 1131 blockInfo.UsesStret = true; 1132 1133 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo); 1134 1135 MangleBuffer name; 1136 CGM.getBlockMangledName(GD, name, blockDecl); 1137 llvm::Function *fn = 1138 llvm::Function::Create(fnLLVMType, llvm::GlobalValue::InternalLinkage, 1139 name.getString(), &CGM.getModule()); 1140 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo); 1141 1142 // Begin generating the function. 1143 StartFunction(blockDecl, fnType->getResultType(), fn, fnInfo, args, 1144 blockInfo.getBlockExpr()->getBody()->getLocStart()); 1145 1146 // Okay. Undo some of what StartFunction did. 1147 1148 // Pull the 'self' reference out of the local decl map. 1149 llvm::Value *blockAddr = LocalDeclMap[&selfDecl]; 1150 LocalDeclMap.erase(&selfDecl); 1151 BlockPointer = Builder.CreateBitCast(blockAddr, 1152 blockInfo.StructureType->getPointerTo(), 1153 "block"); 1154 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA 1155 // won't delete the dbg.declare intrinsics for captured variables. 1156 llvm::Value *BlockPointerDbgLoc = BlockPointer; 1157 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1158 // Allocate a stack slot for it, so we can point the debugger to it 1159 llvm::AllocaInst *Alloca = CreateTempAlloca(BlockPointer->getType(), 1160 "block.addr"); 1161 unsigned Align = getContext().getDeclAlign(&selfDecl).getQuantity(); 1162 Alloca->setAlignment(Align); 1163 // Set the DebugLocation to empty, so the store is recognized as a 1164 // frame setup instruction by llvm::DwarfDebug::beginFunction(). 1165 NoLocation NL(*this, Builder); 1166 Builder.CreateAlignedStore(BlockPointer, Alloca, Align); 1167 BlockPointerDbgLoc = Alloca; 1168 } 1169 1170 // If we have a C++ 'this' reference, go ahead and force it into 1171 // existence now. 1172 if (blockDecl->capturesCXXThis()) { 1173 llvm::Value *addr = Builder.CreateStructGEP(BlockPointer, 1174 blockInfo.CXXThisIndex, 1175 "block.captured-this"); 1176 CXXThisValue = Builder.CreateLoad(addr, "this"); 1177 } 1178 1179 // Also force all the constant captures. 1180 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1181 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1182 const VarDecl *variable = ci->getVariable(); 1183 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1184 if (!capture.isConstant()) continue; 1185 1186 unsigned align = getContext().getDeclAlign(variable).getQuantity(); 1187 1188 llvm::AllocaInst *alloca = 1189 CreateMemTemp(variable->getType(), "block.captured-const"); 1190 alloca->setAlignment(align); 1191 1192 Builder.CreateAlignedStore(capture.getConstant(), alloca, align); 1193 1194 LocalDeclMap[variable] = alloca; 1195 } 1196 1197 // Save a spot to insert the debug information for all the DeclRefExprs. 1198 llvm::BasicBlock *entry = Builder.GetInsertBlock(); 1199 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); 1200 --entry_ptr; 1201 1202 if (IsLambdaConversionToBlock) 1203 EmitLambdaBlockInvokeBody(); 1204 else 1205 EmitStmt(blockDecl->getBody()); 1206 1207 // Remember where we were... 1208 llvm::BasicBlock *resume = Builder.GetInsertBlock(); 1209 1210 // Go back to the entry. 1211 ++entry_ptr; 1212 Builder.SetInsertPoint(entry, entry_ptr); 1213 1214 // Emit debug information for all the DeclRefExprs. 1215 // FIXME: also for 'this' 1216 if (CGDebugInfo *DI = getDebugInfo()) { 1217 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1218 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1219 const VarDecl *variable = ci->getVariable(); 1220 DI->EmitLocation(Builder, variable->getLocation()); 1221 1222 if (CGM.getCodeGenOpts().getDebugInfo() 1223 >= CodeGenOptions::LimitedDebugInfo) { 1224 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1225 if (capture.isConstant()) { 1226 DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], 1227 Builder); 1228 continue; 1229 } 1230 1231 DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointerDbgLoc, 1232 Builder, blockInfo); 1233 } 1234 } 1235 // Recover location if it was changed in the above loop. 1236 DI->EmitLocation(Builder, 1237 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1238 } 1239 1240 // And resume where we left off. 1241 if (resume == 0) 1242 Builder.ClearInsertionPoint(); 1243 else 1244 Builder.SetInsertPoint(resume); 1245 1246 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); 1247 1248 return fn; 1249} 1250 1251/* 1252 notes.push_back(HelperInfo()); 1253 HelperInfo ¬e = notes.back(); 1254 note.index = capture.getIndex(); 1255 note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type)); 1256 note.cxxbar_import = ci->getCopyExpr(); 1257 1258 if (ci->isByRef()) { 1259 note.flag = BLOCK_FIELD_IS_BYREF; 1260 if (type.isObjCGCWeak()) 1261 note.flag |= BLOCK_FIELD_IS_WEAK; 1262 } else if (type->isBlockPointerType()) { 1263 note.flag = BLOCK_FIELD_IS_BLOCK; 1264 } else { 1265 note.flag = BLOCK_FIELD_IS_OBJECT; 1266 } 1267 */ 1268 1269 1270/// Generate the copy-helper function for a block closure object: 1271/// static void block_copy_helper(block_t *dst, block_t *src); 1272/// The runtime will have previously initialized 'dst' by doing a 1273/// bit-copy of 'src'. 1274/// 1275/// Note that this copies an entire block closure object to the heap; 1276/// it should not be confused with a 'byref copy helper', which moves 1277/// the contents of an individual __block variable to the heap. 1278llvm::Constant * 1279CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) { 1280 ASTContext &C = getContext(); 1281 1282 FunctionArgList args; 1283 ImplicitParamDecl dstDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1284 args.push_back(&dstDecl); 1285 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1286 args.push_back(&srcDecl); 1287 1288 const CGFunctionInfo &FI = 1289 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1290 FunctionType::ExtInfo(), 1291 /*variadic*/ false); 1292 1293 // FIXME: it would be nice if these were mergeable with things with 1294 // identical semantics. 1295 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1296 1297 llvm::Function *Fn = 1298 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1299 "__copy_helper_block_", &CGM.getModule()); 1300 1301 IdentifierInfo *II 1302 = &CGM.getContext().Idents.get("__copy_helper_block_"); 1303 1304 FunctionDecl *FD = FunctionDecl::Create(C, 1305 C.getTranslationUnitDecl(), 1306 SourceLocation(), 1307 SourceLocation(), II, C.VoidTy, 0, 1308 SC_Static, 1309 false, 1310 false); 1311 // Create a scope with an artificial location for the body of this function. 1312 ArtificialLocation AL(*this, Builder); 1313 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1314 AL.Emit(); 1315 1316 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1317 1318 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1319 src = Builder.CreateLoad(src); 1320 src = Builder.CreateBitCast(src, structPtrTy, "block.source"); 1321 1322 llvm::Value *dst = GetAddrOfLocalVar(&dstDecl); 1323 dst = Builder.CreateLoad(dst); 1324 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest"); 1325 1326 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1327 1328 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1329 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1330 const VarDecl *variable = ci->getVariable(); 1331 QualType type = variable->getType(); 1332 1333 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1334 if (capture.isConstant()) continue; 1335 1336 const Expr *copyExpr = ci->getCopyExpr(); 1337 BlockFieldFlags flags; 1338 1339 bool useARCWeakCopy = false; 1340 bool useARCStrongCopy = false; 1341 1342 if (copyExpr) { 1343 assert(!ci->isByRef()); 1344 // don't bother computing flags 1345 1346 } else if (ci->isByRef()) { 1347 flags = BLOCK_FIELD_IS_BYREF; 1348 if (type.isObjCGCWeak()) 1349 flags |= BLOCK_FIELD_IS_WEAK; 1350 1351 } else if (type->isObjCRetainableType()) { 1352 flags = BLOCK_FIELD_IS_OBJECT; 1353 bool isBlockPointer = type->isBlockPointerType(); 1354 if (isBlockPointer) 1355 flags = BLOCK_FIELD_IS_BLOCK; 1356 1357 // Special rules for ARC captures: 1358 if (getLangOpts().ObjCAutoRefCount) { 1359 Qualifiers qs = type.getQualifiers(); 1360 1361 // We need to register __weak direct captures with the runtime. 1362 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) { 1363 useARCWeakCopy = true; 1364 1365 // We need to retain the copied value for __strong direct captures. 1366 } else if (qs.getObjCLifetime() == Qualifiers::OCL_Strong) { 1367 // If it's a block pointer, we have to copy the block and 1368 // assign that to the destination pointer, so we might as 1369 // well use _Block_object_assign. Otherwise we can avoid that. 1370 if (!isBlockPointer) 1371 useARCStrongCopy = true; 1372 1373 // Otherwise the memcpy is fine. 1374 } else { 1375 continue; 1376 } 1377 1378 // Non-ARC captures of retainable pointers are strong and 1379 // therefore require a call to _Block_object_assign. 1380 } else { 1381 // fall through 1382 } 1383 } else { 1384 continue; 1385 } 1386 1387 unsigned index = capture.getIndex(); 1388 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1389 llvm::Value *dstField = Builder.CreateStructGEP(dst, index); 1390 1391 // If there's an explicit copy expression, we do that. 1392 if (copyExpr) { 1393 EmitSynthesizedCXXCopyCtor(dstField, srcField, copyExpr); 1394 } else if (useARCWeakCopy) { 1395 EmitARCCopyWeak(dstField, srcField); 1396 } else { 1397 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src"); 1398 if (useARCStrongCopy) { 1399 // At -O0, store null into the destination field (so that the 1400 // storeStrong doesn't over-release) and then call storeStrong. 1401 // This is a workaround to not having an initStrong call. 1402 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1403 llvm::PointerType *ty = cast<llvm::PointerType>(srcValue->getType()); 1404 llvm::Value *null = llvm::ConstantPointerNull::get(ty); 1405 Builder.CreateStore(null, dstField); 1406 EmitARCStoreStrongCall(dstField, srcValue, true); 1407 1408 // With optimization enabled, take advantage of the fact that 1409 // the blocks runtime guarantees a memcpy of the block data, and 1410 // just emit a retain of the src field. 1411 } else { 1412 EmitARCRetainNonBlock(srcValue); 1413 1414 // We don't need this anymore, so kill it. It's not quite 1415 // worth the annoyance to avoid creating it in the first place. 1416 cast<llvm::Instruction>(dstField)->eraseFromParent(); 1417 } 1418 } else { 1419 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy); 1420 llvm::Value *dstAddr = Builder.CreateBitCast(dstField, VoidPtrTy); 1421 llvm::Value *args[] = { 1422 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 1423 }; 1424 1425 bool copyCanThrow = false; 1426 if (ci->isByRef() && variable->getType()->getAsCXXRecordDecl()) { 1427 const Expr *copyExpr = 1428 CGM.getContext().getBlockVarCopyInits(variable); 1429 if (copyExpr) { 1430 copyCanThrow = true; // FIXME: reuse the noexcept logic 1431 } 1432 } 1433 1434 if (copyCanThrow) { 1435 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args); 1436 } else { 1437 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args); 1438 } 1439 } 1440 } 1441 } 1442 1443 FinishFunction(); 1444 1445 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1446} 1447 1448/// Generate the destroy-helper function for a block closure object: 1449/// static void block_destroy_helper(block_t *theBlock); 1450/// 1451/// Note that this destroys a heap-allocated block closure object; 1452/// it should not be confused with a 'byref destroy helper', which 1453/// destroys the heap-allocated contents of an individual __block 1454/// variable. 1455llvm::Constant * 1456CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { 1457 ASTContext &C = getContext(); 1458 1459 FunctionArgList args; 1460 ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); 1461 args.push_back(&srcDecl); 1462 1463 const CGFunctionInfo &FI = 1464 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 1465 FunctionType::ExtInfo(), 1466 /*variadic*/ false); 1467 1468 // FIXME: We'd like to put these into a mergable by content, with 1469 // internal linkage. 1470 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 1471 1472 llvm::Function *Fn = 1473 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1474 "__destroy_helper_block_", &CGM.getModule()); 1475 1476 IdentifierInfo *II 1477 = &CGM.getContext().Idents.get("__destroy_helper_block_"); 1478 1479 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), 1480 SourceLocation(), 1481 SourceLocation(), II, C.VoidTy, 0, 1482 SC_Static, 1483 false, false); 1484 // Create a scope with an artificial location for the body of this function. 1485 ArtificialLocation AL(*this, Builder); 1486 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 1487 AL.Emit(); 1488 1489 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); 1490 1491 llvm::Value *src = GetAddrOfLocalVar(&srcDecl); 1492 src = Builder.CreateLoad(src); 1493 src = Builder.CreateBitCast(src, structPtrTy, "block"); 1494 1495 const BlockDecl *blockDecl = blockInfo.getBlockDecl(); 1496 1497 CodeGenFunction::RunCleanupsScope cleanups(*this); 1498 1499 for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), 1500 ce = blockDecl->capture_end(); ci != ce; ++ci) { 1501 const VarDecl *variable = ci->getVariable(); 1502 QualType type = variable->getType(); 1503 1504 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); 1505 if (capture.isConstant()) continue; 1506 1507 BlockFieldFlags flags; 1508 const CXXDestructorDecl *dtor = 0; 1509 1510 bool useARCWeakDestroy = false; 1511 bool useARCStrongDestroy = false; 1512 1513 if (ci->isByRef()) { 1514 flags = BLOCK_FIELD_IS_BYREF; 1515 if (type.isObjCGCWeak()) 1516 flags |= BLOCK_FIELD_IS_WEAK; 1517 } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1518 if (record->hasTrivialDestructor()) 1519 continue; 1520 dtor = record->getDestructor(); 1521 } else if (type->isObjCRetainableType()) { 1522 flags = BLOCK_FIELD_IS_OBJECT; 1523 if (type->isBlockPointerType()) 1524 flags = BLOCK_FIELD_IS_BLOCK; 1525 1526 // Special rules for ARC captures. 1527 if (getLangOpts().ObjCAutoRefCount) { 1528 Qualifiers qs = type.getQualifiers(); 1529 1530 // Don't generate special dispose logic for a captured object 1531 // unless it's __strong or __weak. 1532 if (!qs.hasStrongOrWeakObjCLifetime()) 1533 continue; 1534 1535 // Support __weak direct captures. 1536 if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) 1537 useARCWeakDestroy = true; 1538 1539 // Tools really want us to use objc_storeStrong here. 1540 else 1541 useARCStrongDestroy = true; 1542 } 1543 } else { 1544 continue; 1545 } 1546 1547 unsigned index = capture.getIndex(); 1548 llvm::Value *srcField = Builder.CreateStructGEP(src, index); 1549 1550 // If there's an explicit copy expression, we do that. 1551 if (dtor) { 1552 PushDestructorCleanup(dtor, srcField); 1553 1554 // If this is a __weak capture, emit the release directly. 1555 } else if (useARCWeakDestroy) { 1556 EmitARCDestroyWeak(srcField); 1557 1558 // Destroy strong objects with a call if requested. 1559 } else if (useARCStrongDestroy) { 1560 EmitARCDestroyStrong(srcField, ARCImpreciseLifetime); 1561 1562 // Otherwise we call _Block_object_dispose. It wouldn't be too 1563 // hard to just emit this as a cleanup if we wanted to make sure 1564 // that things were done in reverse. 1565 } else { 1566 llvm::Value *value = Builder.CreateLoad(srcField); 1567 value = Builder.CreateBitCast(value, VoidPtrTy); 1568 BuildBlockRelease(value, flags); 1569 } 1570 } 1571 1572 cleanups.ForceCleanup(); 1573 1574 FinishFunction(); 1575 1576 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 1577} 1578 1579namespace { 1580 1581/// Emits the copy/dispose helper functions for a __block object of id type. 1582class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers { 1583 BlockFieldFlags Flags; 1584 1585public: 1586 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags) 1587 : ByrefHelpers(alignment), Flags(flags) {} 1588 1589 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1590 llvm::Value *srcField) { 1591 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy); 1592 1593 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy); 1594 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField); 1595 1596 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask(); 1597 1598 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags); 1599 llvm::Value *fn = CGF.CGM.getBlockObjectAssign(); 1600 1601 llvm::Value *args[] = { destField, srcValue, flagsVal }; 1602 CGF.EmitNounwindRuntimeCall(fn, args); 1603 } 1604 1605 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1606 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0)); 1607 llvm::Value *value = CGF.Builder.CreateLoad(field); 1608 1609 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER); 1610 } 1611 1612 void profileImpl(llvm::FoldingSetNodeID &id) const { 1613 id.AddInteger(Flags.getBitMask()); 1614 } 1615}; 1616 1617/// Emits the copy/dispose helpers for an ARC __block __weak variable. 1618class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers { 1619public: 1620 ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1621 1622 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1623 llvm::Value *srcField) { 1624 CGF.EmitARCMoveWeak(destField, srcField); 1625 } 1626 1627 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1628 CGF.EmitARCDestroyWeak(field); 1629 } 1630 1631 void profileImpl(llvm::FoldingSetNodeID &id) const { 1632 // 0 is distinguishable from all pointers and byref flags 1633 id.AddInteger(0); 1634 } 1635}; 1636 1637/// Emits the copy/dispose helpers for an ARC __block __strong variable 1638/// that's not of block-pointer type. 1639class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers { 1640public: 1641 ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1642 1643 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1644 llvm::Value *srcField) { 1645 // Do a "move" by copying the value and then zeroing out the old 1646 // variable. 1647 1648 llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField); 1649 value->setAlignment(Alignment.getQuantity()); 1650 1651 llvm::Value *null = 1652 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType())); 1653 1654 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) { 1655 llvm::StoreInst *store = CGF.Builder.CreateStore(null, destField); 1656 store->setAlignment(Alignment.getQuantity()); 1657 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true); 1658 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true); 1659 return; 1660 } 1661 llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField); 1662 store->setAlignment(Alignment.getQuantity()); 1663 1664 store = CGF.Builder.CreateStore(null, srcField); 1665 store->setAlignment(Alignment.getQuantity()); 1666 } 1667 1668 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1669 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1670 } 1671 1672 void profileImpl(llvm::FoldingSetNodeID &id) const { 1673 // 1 is distinguishable from all pointers and byref flags 1674 id.AddInteger(1); 1675 } 1676}; 1677 1678/// Emits the copy/dispose helpers for an ARC __block __strong 1679/// variable that's of block-pointer type. 1680class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers { 1681public: 1682 ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} 1683 1684 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1685 llvm::Value *srcField) { 1686 // Do the copy with objc_retainBlock; that's all that 1687 // _Block_object_assign would do anyway, and we'd have to pass the 1688 // right arguments to make sure it doesn't get no-op'ed. 1689 llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField); 1690 oldValue->setAlignment(Alignment.getQuantity()); 1691 1692 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true); 1693 1694 llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField); 1695 store->setAlignment(Alignment.getQuantity()); 1696 } 1697 1698 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1699 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime); 1700 } 1701 1702 void profileImpl(llvm::FoldingSetNodeID &id) const { 1703 // 2 is distinguishable from all pointers and byref flags 1704 id.AddInteger(2); 1705 } 1706}; 1707 1708/// Emits the copy/dispose helpers for a __block variable with a 1709/// nontrivial copy constructor or destructor. 1710class CXXByrefHelpers : public CodeGenModule::ByrefHelpers { 1711 QualType VarType; 1712 const Expr *CopyExpr; 1713 1714public: 1715 CXXByrefHelpers(CharUnits alignment, QualType type, 1716 const Expr *copyExpr) 1717 : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {} 1718 1719 bool needsCopy() const { return CopyExpr != 0; } 1720 void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, 1721 llvm::Value *srcField) { 1722 if (!CopyExpr) return; 1723 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr); 1724 } 1725 1726 void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { 1727 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin(); 1728 CGF.PushDestructorCleanup(VarType, field); 1729 CGF.PopCleanupBlocks(cleanupDepth); 1730 } 1731 1732 void profileImpl(llvm::FoldingSetNodeID &id) const { 1733 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr()); 1734 } 1735}; 1736} // end anonymous namespace 1737 1738static llvm::Constant * 1739generateByrefCopyHelper(CodeGenFunction &CGF, 1740 llvm::StructType &byrefType, 1741 unsigned valueFieldIndex, 1742 CodeGenModule::ByrefHelpers &byrefInfo) { 1743 ASTContext &Context = CGF.getContext(); 1744 1745 QualType R = Context.VoidTy; 1746 1747 FunctionArgList args; 1748 ImplicitParamDecl dst(0, SourceLocation(), 0, Context.VoidPtrTy); 1749 args.push_back(&dst); 1750 1751 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1752 args.push_back(&src); 1753 1754 const CGFunctionInfo &FI = 1755 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1756 FunctionType::ExtInfo(), 1757 /*variadic*/ false); 1758 1759 CodeGenTypes &Types = CGF.CGM.getTypes(); 1760 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1761 1762 // FIXME: We'd like to put these into a mergable by content, with 1763 // internal linkage. 1764 llvm::Function *Fn = 1765 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1766 "__Block_byref_object_copy_", &CGF.CGM.getModule()); 1767 1768 IdentifierInfo *II 1769 = &Context.Idents.get("__Block_byref_object_copy_"); 1770 1771 FunctionDecl *FD = FunctionDecl::Create(Context, 1772 Context.getTranslationUnitDecl(), 1773 SourceLocation(), 1774 SourceLocation(), II, R, 0, 1775 SC_Static, 1776 false, false); 1777 1778 CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); 1779 1780 if (byrefInfo.needsCopy()) { 1781 llvm::Type *byrefPtrType = byrefType.getPointerTo(0); 1782 1783 // dst->x 1784 llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst); 1785 destField = CGF.Builder.CreateLoad(destField); 1786 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType); 1787 destField = CGF.Builder.CreateStructGEP(destField, valueFieldIndex, "x"); 1788 1789 // src->x 1790 llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src); 1791 srcField = CGF.Builder.CreateLoad(srcField); 1792 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType); 1793 srcField = CGF.Builder.CreateStructGEP(srcField, valueFieldIndex, "x"); 1794 1795 byrefInfo.emitCopy(CGF, destField, srcField); 1796 } 1797 1798 CGF.FinishFunction(); 1799 1800 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1801} 1802 1803/// Build the copy helper for a __block variable. 1804static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM, 1805 llvm::StructType &byrefType, 1806 unsigned byrefValueIndex, 1807 CodeGenModule::ByrefHelpers &info) { 1808 CodeGenFunction CGF(CGM); 1809 return generateByrefCopyHelper(CGF, byrefType, byrefValueIndex, info); 1810} 1811 1812/// Generate code for a __block variable's dispose helper. 1813static llvm::Constant * 1814generateByrefDisposeHelper(CodeGenFunction &CGF, 1815 llvm::StructType &byrefType, 1816 unsigned byrefValueIndex, 1817 CodeGenModule::ByrefHelpers &byrefInfo) { 1818 ASTContext &Context = CGF.getContext(); 1819 QualType R = Context.VoidTy; 1820 1821 FunctionArgList args; 1822 ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); 1823 args.push_back(&src); 1824 1825 const CGFunctionInfo &FI = 1826 CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, 1827 FunctionType::ExtInfo(), 1828 /*variadic*/ false); 1829 1830 CodeGenTypes &Types = CGF.CGM.getTypes(); 1831 llvm::FunctionType *LTy = Types.GetFunctionType(FI); 1832 1833 // FIXME: We'd like to put these into a mergable by content, with 1834 // internal linkage. 1835 llvm::Function *Fn = 1836 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 1837 "__Block_byref_object_dispose_", 1838 &CGF.CGM.getModule()); 1839 1840 IdentifierInfo *II 1841 = &Context.Idents.get("__Block_byref_object_dispose_"); 1842 1843 FunctionDecl *FD = FunctionDecl::Create(Context, 1844 Context.getTranslationUnitDecl(), 1845 SourceLocation(), 1846 SourceLocation(), II, R, 0, 1847 SC_Static, 1848 false, false); 1849 CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); 1850 1851 if (byrefInfo.needsDispose()) { 1852 llvm::Value *V = CGF.GetAddrOfLocalVar(&src); 1853 V = CGF.Builder.CreateLoad(V); 1854 V = CGF.Builder.CreateBitCast(V, byrefType.getPointerTo(0)); 1855 V = CGF.Builder.CreateStructGEP(V, byrefValueIndex, "x"); 1856 1857 byrefInfo.emitDispose(CGF, V); 1858 } 1859 1860 CGF.FinishFunction(); 1861 1862 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); 1863} 1864 1865/// Build the dispose helper for a __block variable. 1866static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM, 1867 llvm::StructType &byrefType, 1868 unsigned byrefValueIndex, 1869 CodeGenModule::ByrefHelpers &info) { 1870 CodeGenFunction CGF(CGM); 1871 return generateByrefDisposeHelper(CGF, byrefType, byrefValueIndex, info); 1872} 1873 1874/// Lazily build the copy and dispose helpers for a __block variable 1875/// with the given information. 1876template <class T> static T *buildByrefHelpers(CodeGenModule &CGM, 1877 llvm::StructType &byrefTy, 1878 unsigned byrefValueIndex, 1879 T &byrefInfo) { 1880 // Increase the field's alignment to be at least pointer alignment, 1881 // since the layout of the byref struct will guarantee at least that. 1882 byrefInfo.Alignment = std::max(byrefInfo.Alignment, 1883 CharUnits::fromQuantity(CGM.PointerAlignInBytes)); 1884 1885 llvm::FoldingSetNodeID id; 1886 byrefInfo.Profile(id); 1887 1888 void *insertPos; 1889 CodeGenModule::ByrefHelpers *node 1890 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos); 1891 if (node) return static_cast<T*>(node); 1892 1893 byrefInfo.CopyHelper = 1894 buildByrefCopyHelper(CGM, byrefTy, byrefValueIndex, byrefInfo); 1895 byrefInfo.DisposeHelper = 1896 buildByrefDisposeHelper(CGM, byrefTy, byrefValueIndex,byrefInfo); 1897 1898 T *copy = new (CGM.getContext()) T(byrefInfo); 1899 CGM.ByrefHelpersCache.InsertNode(copy, insertPos); 1900 return copy; 1901} 1902 1903/// Build the copy and dispose helpers for the given __block variable 1904/// emission. Places the helpers in the global cache. Returns null 1905/// if no helpers are required. 1906CodeGenModule::ByrefHelpers * 1907CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType, 1908 const AutoVarEmission &emission) { 1909 const VarDecl &var = *emission.Variable; 1910 QualType type = var.getType(); 1911 1912 unsigned byrefValueIndex = getByRefValueLLVMField(&var); 1913 1914 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { 1915 const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var); 1916 if (!copyExpr && record->hasTrivialDestructor()) return 0; 1917 1918 CXXByrefHelpers byrefInfo(emission.Alignment, type, copyExpr); 1919 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1920 } 1921 1922 // Otherwise, if we don't have a retainable type, there's nothing to do. 1923 // that the runtime does extra copies. 1924 if (!type->isObjCRetainableType()) return 0; 1925 1926 Qualifiers qs = type.getQualifiers(); 1927 1928 // If we have lifetime, that dominates. 1929 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) { 1930 assert(getLangOpts().ObjCAutoRefCount); 1931 1932 switch (lifetime) { 1933 case Qualifiers::OCL_None: llvm_unreachable("impossible"); 1934 1935 // These are just bits as far as the runtime is concerned. 1936 case Qualifiers::OCL_ExplicitNone: 1937 case Qualifiers::OCL_Autoreleasing: 1938 return 0; 1939 1940 // Tell the runtime that this is ARC __weak, called by the 1941 // byref routines. 1942 case Qualifiers::OCL_Weak: { 1943 ARCWeakByrefHelpers byrefInfo(emission.Alignment); 1944 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1945 } 1946 1947 // ARC __strong __block variables need to be retained. 1948 case Qualifiers::OCL_Strong: 1949 // Block pointers need to be copied, and there's no direct 1950 // transfer possible. 1951 if (type->isBlockPointerType()) { 1952 ARCStrongBlockByrefHelpers byrefInfo(emission.Alignment); 1953 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1954 1955 // Otherwise, we transfer ownership of the retain from the stack 1956 // to the heap. 1957 } else { 1958 ARCStrongByrefHelpers byrefInfo(emission.Alignment); 1959 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1960 } 1961 } 1962 llvm_unreachable("fell out of lifetime switch!"); 1963 } 1964 1965 BlockFieldFlags flags; 1966 if (type->isBlockPointerType()) { 1967 flags |= BLOCK_FIELD_IS_BLOCK; 1968 } else if (CGM.getContext().isObjCNSObjectType(type) || 1969 type->isObjCObjectPointerType()) { 1970 flags |= BLOCK_FIELD_IS_OBJECT; 1971 } else { 1972 return 0; 1973 } 1974 1975 if (type.isObjCGCWeak()) 1976 flags |= BLOCK_FIELD_IS_WEAK; 1977 1978 ObjectByrefHelpers byrefInfo(emission.Alignment, flags); 1979 return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo); 1980} 1981 1982unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const { 1983 assert(ByRefValueInfo.count(VD) && "Did not find value!"); 1984 1985 return ByRefValueInfo.find(VD)->second.second; 1986} 1987 1988llvm::Value *CodeGenFunction::BuildBlockByrefAddress(llvm::Value *BaseAddr, 1989 const VarDecl *V) { 1990 llvm::Value *Loc = Builder.CreateStructGEP(BaseAddr, 1, "forwarding"); 1991 Loc = Builder.CreateLoad(Loc); 1992 Loc = Builder.CreateStructGEP(Loc, getByRefValueLLVMField(V), 1993 V->getNameAsString()); 1994 return Loc; 1995} 1996 1997/// BuildByRefType - This routine changes a __block variable declared as T x 1998/// into: 1999/// 2000/// struct { 2001/// void *__isa; 2002/// void *__forwarding; 2003/// int32_t __flags; 2004/// int32_t __size; 2005/// void *__copy_helper; // only if needed 2006/// void *__destroy_helper; // only if needed 2007/// void *__byref_variable_layout;// only if needed 2008/// char padding[X]; // only if needed 2009/// T x; 2010/// } x 2011/// 2012llvm::Type *CodeGenFunction::BuildByRefType(const VarDecl *D) { 2013 std::pair<llvm::Type *, unsigned> &Info = ByRefValueInfo[D]; 2014 if (Info.first) 2015 return Info.first; 2016 2017 QualType Ty = D->getType(); 2018 2019 SmallVector<llvm::Type *, 8> types; 2020 2021 llvm::StructType *ByRefType = 2022 llvm::StructType::create(getLLVMContext(), 2023 "struct.__block_byref_" + D->getNameAsString()); 2024 2025 // void *__isa; 2026 types.push_back(Int8PtrTy); 2027 2028 // void *__forwarding; 2029 types.push_back(llvm::PointerType::getUnqual(ByRefType)); 2030 2031 // int32_t __flags; 2032 types.push_back(Int32Ty); 2033 2034 // int32_t __size; 2035 types.push_back(Int32Ty); 2036 // Note that this must match *exactly* the logic in buildByrefHelpers. 2037 bool HasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D); 2038 if (HasCopyAndDispose) { 2039 /// void *__copy_helper; 2040 types.push_back(Int8PtrTy); 2041 2042 /// void *__destroy_helper; 2043 types.push_back(Int8PtrTy); 2044 } 2045 bool HasByrefExtendedLayout = false; 2046 Qualifiers::ObjCLifetime Lifetime; 2047 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) && 2048 HasByrefExtendedLayout) 2049 /// void *__byref_variable_layout; 2050 types.push_back(Int8PtrTy); 2051 2052 bool Packed = false; 2053 CharUnits Align = getContext().getDeclAlign(D); 2054 if (Align > 2055 getContext().toCharUnitsFromBits(getTarget().getPointerAlign(0))) { 2056 // We have to insert padding. 2057 2058 // The struct above has 2 32-bit integers. 2059 unsigned CurrentOffsetInBytes = 4 * 2; 2060 2061 // And either 2, 3, 4 or 5 pointers. 2062 unsigned noPointers = 2; 2063 if (HasCopyAndDispose) 2064 noPointers += 2; 2065 if (HasByrefExtendedLayout) 2066 noPointers += 1; 2067 2068 CurrentOffsetInBytes += noPointers * CGM.getDataLayout().getTypeAllocSize(Int8PtrTy); 2069 2070 // Align the offset. 2071 unsigned AlignedOffsetInBytes = 2072 llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity()); 2073 2074 unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes; 2075 if (NumPaddingBytes > 0) { 2076 llvm::Type *Ty = Int8Ty; 2077 // FIXME: We need a sema error for alignment larger than the minimum of 2078 // the maximal stack alignment and the alignment of malloc on the system. 2079 if (NumPaddingBytes > 1) 2080 Ty = llvm::ArrayType::get(Ty, NumPaddingBytes); 2081 2082 types.push_back(Ty); 2083 2084 // We want a packed struct. 2085 Packed = true; 2086 } 2087 } 2088 2089 // T x; 2090 types.push_back(ConvertTypeForMem(Ty)); 2091 2092 ByRefType->setBody(types, Packed); 2093 2094 Info.first = ByRefType; 2095 2096 Info.second = types.size() - 1; 2097 2098 return Info.first; 2099} 2100 2101/// Initialize the structural components of a __block variable, i.e. 2102/// everything but the actual object. 2103void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) { 2104 // Find the address of the local. 2105 llvm::Value *addr = emission.Address; 2106 2107 // That's an alloca of the byref structure type. 2108 llvm::StructType *byrefType = cast<llvm::StructType>( 2109 cast<llvm::PointerType>(addr->getType())->getElementType()); 2110 2111 // Build the byref helpers if necessary. This is null if we don't need any. 2112 CodeGenModule::ByrefHelpers *helpers = 2113 buildByrefHelpers(*byrefType, emission); 2114 2115 const VarDecl &D = *emission.Variable; 2116 QualType type = D.getType(); 2117 2118 bool HasByrefExtendedLayout; 2119 Qualifiers::ObjCLifetime ByrefLifetime; 2120 bool ByRefHasLifetime = 2121 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout); 2122 2123 llvm::Value *V; 2124 2125 // Initialize the 'isa', which is just 0 or 1. 2126 int isa = 0; 2127 if (type.isObjCGCWeak()) 2128 isa = 1; 2129 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa"); 2130 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 0, "byref.isa")); 2131 2132 // Store the address of the variable into its own forwarding pointer. 2133 Builder.CreateStore(addr, 2134 Builder.CreateStructGEP(addr, 1, "byref.forwarding")); 2135 2136 // Blocks ABI: 2137 // c) the flags field is set to either 0 if no helper functions are 2138 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are, 2139 BlockFlags flags; 2140 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE; 2141 if (ByRefHasLifetime) { 2142 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED; 2143 else switch (ByrefLifetime) { 2144 case Qualifiers::OCL_Strong: 2145 flags |= BLOCK_BYREF_LAYOUT_STRONG; 2146 break; 2147 case Qualifiers::OCL_Weak: 2148 flags |= BLOCK_BYREF_LAYOUT_WEAK; 2149 break; 2150 case Qualifiers::OCL_ExplicitNone: 2151 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED; 2152 break; 2153 case Qualifiers::OCL_None: 2154 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType()) 2155 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT; 2156 break; 2157 default: 2158 break; 2159 } 2160 if (CGM.getLangOpts().ObjCGCBitmapPrint) { 2161 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask()); 2162 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE) 2163 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE"); 2164 if (flags & BLOCK_BYREF_LAYOUT_MASK) { 2165 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK); 2166 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED) 2167 printf(" BLOCK_BYREF_LAYOUT_EXTENDED"); 2168 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG) 2169 printf(" BLOCK_BYREF_LAYOUT_STRONG"); 2170 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK) 2171 printf(" BLOCK_BYREF_LAYOUT_WEAK"); 2172 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED) 2173 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED"); 2174 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT) 2175 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT"); 2176 } 2177 printf("\n"); 2178 } 2179 } 2180 2181 Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), 2182 Builder.CreateStructGEP(addr, 2, "byref.flags")); 2183 2184 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType); 2185 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity()); 2186 Builder.CreateStore(V, Builder.CreateStructGEP(addr, 3, "byref.size")); 2187 2188 if (helpers) { 2189 llvm::Value *copy_helper = Builder.CreateStructGEP(addr, 4); 2190 Builder.CreateStore(helpers->CopyHelper, copy_helper); 2191 2192 llvm::Value *destroy_helper = Builder.CreateStructGEP(addr, 5); 2193 Builder.CreateStore(helpers->DisposeHelper, destroy_helper); 2194 } 2195 if (ByRefHasLifetime && HasByrefExtendedLayout) { 2196 llvm::Constant* ByrefLayoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type); 2197 llvm::Value *ByrefInfoAddr = Builder.CreateStructGEP(addr, helpers ? 6 : 4, 2198 "byref.layout"); 2199 // cast destination to pointer to source type. 2200 llvm::Type *DesTy = ByrefLayoutInfo->getType(); 2201 DesTy = DesTy->getPointerTo(); 2202 llvm::Value *BC = Builder.CreatePointerCast(ByrefInfoAddr, DesTy); 2203 Builder.CreateStore(ByrefLayoutInfo, BC); 2204 } 2205} 2206 2207void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) { 2208 llvm::Value *F = CGM.getBlockObjectDispose(); 2209 llvm::Value *args[] = { 2210 Builder.CreateBitCast(V, Int8PtrTy), 2211 llvm::ConstantInt::get(Int32Ty, flags.getBitMask()) 2212 }; 2213 EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors? 2214} 2215 2216namespace { 2217 struct CallBlockRelease : EHScopeStack::Cleanup { 2218 llvm::Value *Addr; 2219 CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {} 2220 2221 void Emit(CodeGenFunction &CGF, Flags flags) { 2222 // Should we be passing FIELD_IS_WEAK here? 2223 CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF); 2224 } 2225 }; 2226} 2227 2228/// Enter a cleanup to destroy a __block variable. Note that this 2229/// cleanup should be a no-op if the variable hasn't left the stack 2230/// yet; if a cleanup is required for the variable itself, that needs 2231/// to be done externally. 2232void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) { 2233 // We don't enter this cleanup if we're in pure-GC mode. 2234 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) 2235 return; 2236 2237 EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address); 2238} 2239 2240/// Adjust the declaration of something from the blocks API. 2241static void configureBlocksRuntimeObject(CodeGenModule &CGM, 2242 llvm::Constant *C) { 2243 if (!CGM.getLangOpts().BlocksRuntimeOptional) return; 2244 2245 llvm::GlobalValue *GV = cast<llvm::GlobalValue>(C->stripPointerCasts()); 2246 if (GV->isDeclaration() && 2247 GV->getLinkage() == llvm::GlobalValue::ExternalLinkage) 2248 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 2249} 2250 2251llvm::Constant *CodeGenModule::getBlockObjectDispose() { 2252 if (BlockObjectDispose) 2253 return BlockObjectDispose; 2254 2255 llvm::Type *args[] = { Int8PtrTy, Int32Ty }; 2256 llvm::FunctionType *fty 2257 = llvm::FunctionType::get(VoidTy, args, false); 2258 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose"); 2259 configureBlocksRuntimeObject(*this, BlockObjectDispose); 2260 return BlockObjectDispose; 2261} 2262 2263llvm::Constant *CodeGenModule::getBlockObjectAssign() { 2264 if (BlockObjectAssign) 2265 return BlockObjectAssign; 2266 2267 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty }; 2268 llvm::FunctionType *fty 2269 = llvm::FunctionType::get(VoidTy, args, false); 2270 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign"); 2271 configureBlocksRuntimeObject(*this, BlockObjectAssign); 2272 return BlockObjectAssign; 2273} 2274 2275llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { 2276 if (NSConcreteGlobalBlock) 2277 return NSConcreteGlobalBlock; 2278 2279 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock", 2280 Int8PtrTy->getPointerTo(), 0); 2281 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock); 2282 return NSConcreteGlobalBlock; 2283} 2284 2285llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { 2286 if (NSConcreteStackBlock) 2287 return NSConcreteStackBlock; 2288 2289 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock", 2290 Int8PtrTy->getPointerTo(), 0); 2291 configureBlocksRuntimeObject(*this, NSConcreteStackBlock); 2292 return NSConcreteStackBlock; 2293} 2294