Bug Summary

File:tools/clang/lib/CodeGen/CGBlocks.cpp
Warning:line 594, column 19
Forming reference to null pointer

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGBlocks.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/CodeGen -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp -faddrsig
1//===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
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 "CGCXXABI.h"
16#include "CGDebugInfo.h"
17#include "CGObjCRuntime.h"
18#include "CGOpenCLRuntime.h"
19#include "CodeGenFunction.h"
20#include "CodeGenModule.h"
21#include "ConstantEmitter.h"
22#include "TargetInfo.h"
23#include "clang/AST/DeclObjC.h"
24#include "clang/CodeGen/ConstantInitBuilder.h"
25#include "llvm/ADT/SmallSet.h"
26#include "llvm/IR/CallSite.h"
27#include "llvm/IR/DataLayout.h"
28#include "llvm/IR/Module.h"
29#include "llvm/Support/ScopedPrinter.h"
30#include <algorithm>
31#include <cstdio>
32
33using namespace clang;
34using namespace CodeGen;
35
36CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
37 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
38 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
39 CapturesNonExternalType(false), LocalAddress(Address::invalid()),
40 StructureType(nullptr), Block(block), DominatingIP(nullptr) {
41
42 // Skip asm prefix, if any. 'name' is usually taken directly from
43 // the mangled name of the enclosing function.
44 if (!name.empty() && name[0] == '\01')
45 name = name.substr(1);
46}
47
48// Anchor the vtable to this translation unit.
49BlockByrefHelpers::~BlockByrefHelpers() {}
50
51/// Build the given block as a global block.
52static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
53 const CGBlockInfo &blockInfo,
54 llvm::Constant *blockFn);
55
56/// Build the helper function to copy a block.
57static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
58 const CGBlockInfo &blockInfo) {
59 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
60}
61
62/// Build the helper function to dispose of a block.
63static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
64 const CGBlockInfo &blockInfo) {
65 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
66}
67
68namespace {
69
70/// Represents a type of copy/destroy operation that should be performed for an
71/// entity that's captured by a block.
72enum class BlockCaptureEntityKind {
73 CXXRecord, // Copy or destroy
74 ARCWeak,
75 ARCStrong,
76 NonTrivialCStruct,
77 BlockObject, // Assign or release
78 None
79};
80
81/// Represents a captured entity that requires extra operations in order for
82/// this entity to be copied or destroyed correctly.
83struct BlockCaptureManagedEntity {
84 BlockCaptureEntityKind CopyKind, DisposeKind;
85 BlockFieldFlags CopyFlags, DisposeFlags;
86 const BlockDecl::Capture *CI;
87 const CGBlockInfo::Capture *Capture;
88
89 BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
90 BlockCaptureEntityKind DisposeType,
91 BlockFieldFlags CopyFlags,
92 BlockFieldFlags DisposeFlags,
93 const BlockDecl::Capture &CI,
94 const CGBlockInfo::Capture &Capture)
95 : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
96 DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
97
98 bool operator<(const BlockCaptureManagedEntity &Other) const {
99 return Capture->getOffset() < Other.Capture->getOffset();
100 }
101};
102
103enum class CaptureStrKind {
104 // String for the copy helper.
105 CopyHelper,
106 // String for the dispose helper.
107 DisposeHelper,
108 // Merge the strings for the copy helper and dispose helper.
109 Merged
110};
111
112} // end anonymous namespace
113
114static void findBlockCapturedManagedEntities(
115 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
116 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
117
118static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
119 CaptureStrKind StrKind,
120 CharUnits BlockAlignment,
121 CodeGenModule &CGM);
122
123static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
124 CodeGenModule &CGM) {
125 std::string Name = "__block_descriptor_";
126 Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
127
128 if (BlockInfo.needsCopyDisposeHelpers()) {
129 if (CGM.getLangOpts().Exceptions)
130 Name += "e";
131 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
132 Name += "a";
133 Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
134
135 SmallVector<BlockCaptureManagedEntity, 4> ManagedCaptures;
136 findBlockCapturedManagedEntities(BlockInfo, CGM.getContext().getLangOpts(),
137 ManagedCaptures);
138
139 for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
140 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
141
142 if (E.CopyKind == E.DisposeKind) {
143 // If CopyKind and DisposeKind are the same, merge the capture
144 // information.
145 assert(E.CopyKind != BlockCaptureEntityKind::None &&((E.CopyKind != BlockCaptureEntityKind::None && "shouldn't see BlockCaptureManagedEntity that is None"
) ? static_cast<void> (0) : __assert_fail ("E.CopyKind != BlockCaptureEntityKind::None && \"shouldn't see BlockCaptureManagedEntity that is None\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 146, __PRETTY_FUNCTION__))
146 "shouldn't see BlockCaptureManagedEntity that is None")((E.CopyKind != BlockCaptureEntityKind::None && "shouldn't see BlockCaptureManagedEntity that is None"
) ? static_cast<void> (0) : __assert_fail ("E.CopyKind != BlockCaptureEntityKind::None && \"shouldn't see BlockCaptureManagedEntity that is None\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 146, __PRETTY_FUNCTION__))
;
147 Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
148 BlockInfo.BlockAlign, CGM);
149 } else {
150 // If CopyKind and DisposeKind are not the same, which can happen when
151 // either Kind is None or the captured object is a __strong block,
152 // concatenate the copy and dispose strings.
153 Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
154 BlockInfo.BlockAlign, CGM);
155 Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
156 BlockInfo.BlockAlign, CGM);
157 }
158 }
159 Name += "_";
160 }
161
162 std::string TypeAtEncoding =
163 CGM.getContext().getObjCEncodingForBlock(BlockInfo.getBlockExpr());
164 Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
165 Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
166 return Name;
167}
168
169/// buildBlockDescriptor - Build the block descriptor meta-data for a block.
170/// buildBlockDescriptor is accessed from 5th field of the Block_literal
171/// meta-data and contains stationary information about the block literal.
172/// Its definition will have 4 (or optionally 6) words.
173/// \code
174/// struct Block_descriptor {
175/// unsigned long reserved;
176/// unsigned long size; // size of Block_literal metadata in bytes.
177/// void *copy_func_helper_decl; // optional copy helper.
178/// void *destroy_func_decl; // optioanl destructor helper.
179/// void *block_method_encoding_address; // @encode for block literal signature.
180/// void *block_layout_info; // encoding of captured block variables.
181/// };
182/// \endcode
183static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
184 const CGBlockInfo &blockInfo) {
185 ASTContext &C = CGM.getContext();
186
187 llvm::IntegerType *ulong =
188 cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
189 llvm::PointerType *i8p = nullptr;
190 if (CGM.getLangOpts().OpenCL)
191 i8p =
192 llvm::Type::getInt8PtrTy(
193 CGM.getLLVMContext(), C.getTargetAddressSpace(LangAS::opencl_constant));
194 else
195 i8p = CGM.VoidPtrTy;
196
197 std::string descName;
198
199 // If an equivalent block descriptor global variable exists, return it.
200 if (C.getLangOpts().ObjC1 &&
201 CGM.getLangOpts().getGC() == LangOptions::NonGC) {
202 descName = getBlockDescriptorName(blockInfo, CGM);
203 if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
204 return llvm::ConstantExpr::getBitCast(desc,
205 CGM.getBlockDescriptorType());
206 }
207
208 // If there isn't an equivalent block descriptor global variable, create a new
209 // one.
210 ConstantInitBuilder builder(CGM);
211 auto elements = builder.beginStruct();
212
213 // reserved
214 elements.addInt(ulong, 0);
215
216 // Size
217 // FIXME: What is the right way to say this doesn't fit? We should give
218 // a user diagnostic in that case. Better fix would be to change the
219 // API to size_t.
220 elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
221
222 // Optional copy/dispose helpers.
223 bool hasInternalHelper = false;
224 if (blockInfo.needsCopyDisposeHelpers()) {
225 // copy_func_helper_decl
226 llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
227 elements.add(copyHelper);
228
229 // destroy_func_decl
230 llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
231 elements.add(disposeHelper);
232
233 if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
234 cast<llvm::Function>(disposeHelper->getOperand(0))
235 ->hasInternalLinkage())
236 hasInternalHelper = true;
237 }
238
239 // Signature. Mandatory ObjC-style method descriptor @encode sequence.
240 std::string typeAtEncoding =
241 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr());
242 elements.add(llvm::ConstantExpr::getBitCast(
243 CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
244
245 // GC layout.
246 if (C.getLangOpts().ObjC1) {
247 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
248 elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
249 else
250 elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
251 }
252 else
253 elements.addNullPointer(i8p);
254
255 unsigned AddrSpace = 0;
256 if (C.getLangOpts().OpenCL)
257 AddrSpace = C.getTargetAddressSpace(LangAS::opencl_constant);
258
259 llvm::GlobalValue::LinkageTypes linkage;
260 if (descName.empty()) {
261 linkage = llvm::GlobalValue::InternalLinkage;
262 descName = "__block_descriptor_tmp";
263 } else if (hasInternalHelper) {
264 // If either the copy helper or the dispose helper has internal linkage,
265 // the block descriptor must have internal linkage too.
266 linkage = llvm::GlobalValue::InternalLinkage;
267 } else {
268 linkage = llvm::GlobalValue::LinkOnceODRLinkage;
269 }
270
271 llvm::GlobalVariable *global =
272 elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
273 /*constant*/ true, linkage, AddrSpace);
274
275 if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
276 global->setVisibility(llvm::GlobalValue::HiddenVisibility);
277 global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
278 }
279
280 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
281}
282
283/*
284 Purely notional variadic template describing the layout of a block.
285
286 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
287 struct Block_literal {
288 /// Initialized to one of:
289 /// extern void *_NSConcreteStackBlock[];
290 /// extern void *_NSConcreteGlobalBlock[];
291 ///
292 /// In theory, we could start one off malloc'ed by setting
293 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
294 /// this isa:
295 /// extern void *_NSConcreteMallocBlock[];
296 struct objc_class *isa;
297
298 /// These are the flags (with corresponding bit number) that the
299 /// compiler is actually supposed to know about.
300 /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
301 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
302 /// descriptor provides copy and dispose helper functions
303 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
304 /// object with a nontrivial destructor or copy constructor
305 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
306 /// as global memory
307 /// 29. BLOCK_USE_STRET - indicates that the block function
308 /// uses stret, which objc_msgSend needs to know about
309 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
310 /// @encoded signature string
311 /// And we're not supposed to manipulate these:
312 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
313 /// to malloc'ed memory
314 /// 27. BLOCK_IS_GC - indicates that the block has been moved to
315 /// to GC-allocated memory
316 /// Additionally, the bottom 16 bits are a reference count which
317 /// should be zero on the stack.
318 int flags;
319
320 /// Reserved; should be zero-initialized.
321 int reserved;
322
323 /// Function pointer generated from block literal.
324 _ResultType (*invoke)(Block_literal *, _ParamTypes...);
325
326 /// Block description metadata generated from block literal.
327 struct Block_descriptor *block_descriptor;
328
329 /// Captured values follow.
330 _CapturesTypes captures...;
331 };
332 */
333
334namespace {
335 /// A chunk of data that we actually have to capture in the block.
336 struct BlockLayoutChunk {
337 CharUnits Alignment;
338 CharUnits Size;
339 Qualifiers::ObjCLifetime Lifetime;
340 const BlockDecl::Capture *Capture; // null for 'this'
341 llvm::Type *Type;
342 QualType FieldType;
343
344 BlockLayoutChunk(CharUnits align, CharUnits size,
345 Qualifiers::ObjCLifetime lifetime,
346 const BlockDecl::Capture *capture,
347 llvm::Type *type, QualType fieldType)
348 : Alignment(align), Size(size), Lifetime(lifetime),
349 Capture(capture), Type(type), FieldType(fieldType) {}
350
351 /// Tell the block info that this chunk has the given field index.
352 void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
353 if (!Capture) {
354 info.CXXThisIndex = index;
355 info.CXXThisOffset = offset;
356 } else {
357 auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
358 info.Captures.insert({Capture->getVariable(), C});
359 }
360 }
361 };
362
363 /// Order by 1) all __strong together 2) next, all byfref together 3) next,
364 /// all __weak together. Preserve descending alignment in all situations.
365 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
366 if (left.Alignment != right.Alignment)
367 return left.Alignment > right.Alignment;
368
369 auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
370 if (chunk.Capture && chunk.Capture->isByRef())
371 return 1;
372 if (chunk.Lifetime == Qualifiers::OCL_Strong)
373 return 0;
374 if (chunk.Lifetime == Qualifiers::OCL_Weak)
375 return 2;
376 return 3;
377 };
378
379 return getPrefOrder(left) < getPrefOrder(right);
380 }
381} // end anonymous namespace
382
383/// Determines if the given type is safe for constant capture in C++.
384static bool isSafeForCXXConstantCapture(QualType type) {
385 const RecordType *recordType =
386 type->getBaseElementTypeUnsafe()->getAs<RecordType>();
387
388 // Only records can be unsafe.
389 if (!recordType) return true;
390
391 const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
392
393 // Maintain semantics for classes with non-trivial dtors or copy ctors.
394 if (!record->hasTrivialDestructor()) return false;
395 if (record->hasNonTrivialCopyConstructor()) return false;
396
397 // Otherwise, we just have to make sure there aren't any mutable
398 // fields that might have changed since initialization.
399 return !record->hasMutableFields();
400}
401
402/// It is illegal to modify a const object after initialization.
403/// Therefore, if a const object has a constant initializer, we don't
404/// actually need to keep storage for it in the block; we'll just
405/// rematerialize it at the start of the block function. This is
406/// acceptable because we make no promises about address stability of
407/// captured variables.
408static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
409 CodeGenFunction *CGF,
410 const VarDecl *var) {
411 // Return if this is a function parameter. We shouldn't try to
412 // rematerialize default arguments of function parameters.
413 if (isa<ParmVarDecl>(var))
414 return nullptr;
415
416 QualType type = var->getType();
417
418 // We can only do this if the variable is const.
419 if (!type.isConstQualified()) return nullptr;
420
421 // Furthermore, in C++ we have to worry about mutable fields:
422 // C++ [dcl.type.cv]p4:
423 // Except that any class member declared mutable can be
424 // modified, any attempt to modify a const object during its
425 // lifetime results in undefined behavior.
426 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
427 return nullptr;
428
429 // If the variable doesn't have any initializer (shouldn't this be
430 // invalid?), it's not clear what we should do. Maybe capture as
431 // zero?
432 const Expr *init = var->getInit();
433 if (!init) return nullptr;
434
435 return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
436}
437
438/// Get the low bit of a nonzero character count. This is the
439/// alignment of the nth byte if the 0th byte is universally aligned.
440static CharUnits getLowBit(CharUnits v) {
441 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
442}
443
444static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
445 SmallVectorImpl<llvm::Type*> &elementTypes) {
446
447 assert(elementTypes.empty())((elementTypes.empty()) ? static_cast<void> (0) : __assert_fail
("elementTypes.empty()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 447, __PRETTY_FUNCTION__))
;
448 if (CGM.getLangOpts().OpenCL) {
449 // The header is basically 'struct { int; int; generic void *;
450 // custom_fields; }'. Assert that struct is packed.
451 auto GenericAS =
452 CGM.getContext().getTargetAddressSpace(LangAS::opencl_generic);
453 auto GenPtrAlign =
454 CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
455 auto GenPtrSize =
456 CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
457 assert(CGM.getIntSize() <= GenPtrSize)((CGM.getIntSize() <= GenPtrSize) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntSize() <= GenPtrSize", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 457, __PRETTY_FUNCTION__))
;
458 assert(CGM.getIntAlign() <= GenPtrAlign)((CGM.getIntAlign() <= GenPtrAlign) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntAlign() <= GenPtrAlign", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 458, __PRETTY_FUNCTION__))
;
459 assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign))(((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign)) ? static_cast
<void> (0) : __assert_fail ("(2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign)"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 459, __PRETTY_FUNCTION__))
;
460 elementTypes.push_back(CGM.IntTy); /* total size */
461 elementTypes.push_back(CGM.IntTy); /* align */
462 elementTypes.push_back(
463 CGM.getOpenCLRuntime()
464 .getGenericVoidPointerType()); /* invoke function */
465 unsigned Offset =
466 2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
467 unsigned BlockAlign = GenPtrAlign.getQuantity();
468 if (auto *Helper =
469 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
470 for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
471 // TargetOpenCLBlockHelp needs to make sure the struct is packed.
472 // If necessary, add padding fields to the custom fields.
473 unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
474 if (BlockAlign < Align)
475 BlockAlign = Align;
476 assert(Offset % Align == 0)((Offset % Align == 0) ? static_cast<void> (0) : __assert_fail
("Offset % Align == 0", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 476, __PRETTY_FUNCTION__))
;
477 Offset += CGM.getDataLayout().getTypeAllocSize(I);
478 elementTypes.push_back(I);
479 }
480 }
481 info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
482 info.BlockSize = CharUnits::fromQuantity(Offset);
483 } else {
484 // The header is basically 'struct { void *; int; int; void *; void *; }'.
485 // Assert that the struct is packed.
486 assert(CGM.getIntSize() <= CGM.getPointerSize())((CGM.getIntSize() <= CGM.getPointerSize()) ? static_cast<
void> (0) : __assert_fail ("CGM.getIntSize() <= CGM.getPointerSize()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 486, __PRETTY_FUNCTION__))
;
487 assert(CGM.getIntAlign() <= CGM.getPointerAlign())((CGM.getIntAlign() <= CGM.getPointerAlign()) ? static_cast
<void> (0) : __assert_fail ("CGM.getIntAlign() <= CGM.getPointerAlign()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 487, __PRETTY_FUNCTION__))
;
488 assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()))(((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()))
? static_cast<void> (0) : __assert_fail ("(2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign())"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 488, __PRETTY_FUNCTION__))
;
489 info.BlockAlign = CGM.getPointerAlign();
490 info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
491 elementTypes.push_back(CGM.VoidPtrTy);
492 elementTypes.push_back(CGM.IntTy);
493 elementTypes.push_back(CGM.IntTy);
494 elementTypes.push_back(CGM.VoidPtrTy);
495 elementTypes.push_back(CGM.getBlockDescriptorType());
496 }
497}
498
499static QualType getCaptureFieldType(const CodeGenFunction &CGF,
500 const BlockDecl::Capture &CI) {
501 const VarDecl *VD = CI.getVariable();
502
503 // If the variable is captured by an enclosing block or lambda expression,
504 // use the type of the capture field.
505 if (CGF.BlockInfo && CI.isNested())
506 return CGF.BlockInfo->getCapture(VD).fieldType();
507 if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
508 return FD->getType();
509 // If the captured variable is a non-escaping __block variable, the field
510 // type is the reference type. If the variable is a __block variable that
511 // already has a reference type, the field type is the variable's type.
512 return VD->isNonEscapingByref() ?
513 CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
514}
515
516/// Compute the layout of the given block. Attempts to lay the block
517/// out with minimal space requirements.
518static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF,
519 CGBlockInfo &info) {
520 ASTContext &C = CGM.getContext();
521 const BlockDecl *block = info.getBlockDecl();
522
523 SmallVector<llvm::Type*, 8> elementTypes;
524 initializeForBlockHeader(CGM, info, elementTypes);
525 bool hasNonConstantCustomFields = false;
526 if (auto *OpenCLHelper =
5
Assuming 'OpenCLHelper' is null
6
Taking false branch
527 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper())
528 hasNonConstantCustomFields =
529 !OpenCLHelper->areAllCustomFieldValuesConstant(info);
530 if (!block->hasCaptures() && !hasNonConstantCustomFields) {
531 info.StructureType =
532 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
533 info.CanBeGlobal = true;
534 return;
535 }
536 else if (C.getLangOpts().ObjC1 &&
7
Assuming the condition is false
537 CGM.getLangOpts().getGC() == LangOptions::NonGC)
538 info.HasCapturedVariableLayout = true;
539
540 // Collect the layout chunks.
541 SmallVector<BlockLayoutChunk, 16> layout;
542 layout.reserve(block->capturesCXXThis() +
543 (block->capture_end() - block->capture_begin()));
544
545 CharUnits maxFieldAlign;
546
547 // First, 'this'.
548 if (block->capturesCXXThis()) {
8
Assuming the condition is false
9
Taking false branch
549 assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&((CGF && CGF->CurFuncDecl && isa<CXXMethodDecl
>(CGF->CurFuncDecl) && "Can't capture 'this' outside a method"
) ? static_cast<void> (0) : __assert_fail ("CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && \"Can't capture 'this' outside a method\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 550, __PRETTY_FUNCTION__))
550 "Can't capture 'this' outside a method")((CGF && CGF->CurFuncDecl && isa<CXXMethodDecl
>(CGF->CurFuncDecl) && "Can't capture 'this' outside a method"
) ? static_cast<void> (0) : __assert_fail ("CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && \"Can't capture 'this' outside a method\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 550, __PRETTY_FUNCTION__))
;
551 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
552
553 // Theoretically, this could be in a different address space, so
554 // don't assume standard pointer size/align.
555 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
556 std::pair<CharUnits,CharUnits> tinfo
557 = CGM.getContext().getTypeInfoInChars(thisType);
558 maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
559
560 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
561 Qualifiers::OCL_None,
562 nullptr, llvmType, thisType));
563 }
564
565 // Next, all the block captures.
566 for (const auto &CI : block->captures()) {
10
Assuming '__begin1' is not equal to '__end1'
567 const VarDecl *variable = CI.getVariable();
568
569 if (CI.isEscapingByref()) {
11
Assuming the condition is false
12
Taking false branch
570 // We have to copy/dispose of the __block reference.
571 info.NeedsCopyDispose = true;
572
573 // Just use void* instead of a pointer to the byref type.
574 CharUnits align = CGM.getPointerAlign();
575 maxFieldAlign = std::max(maxFieldAlign, align);
576
577 // Since a __block variable cannot be captured by lambdas, its type and
578 // the capture field type should always match.
579 assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&((getCaptureFieldType(*CGF, CI) == variable->getType() &&
"capture type differs from the variable type") ? static_cast
<void> (0) : __assert_fail ("getCaptureFieldType(*CGF, CI) == variable->getType() && \"capture type differs from the variable type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 580, __PRETTY_FUNCTION__))
580 "capture type differs from the variable type")((getCaptureFieldType(*CGF, CI) == variable->getType() &&
"capture type differs from the variable type") ? static_cast
<void> (0) : __assert_fail ("getCaptureFieldType(*CGF, CI) == variable->getType() && \"capture type differs from the variable type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 580, __PRETTY_FUNCTION__))
;
581 layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
582 Qualifiers::OCL_None, &CI,
583 CGM.VoidPtrTy, variable->getType()));
584 continue;
585 }
586
587 // Otherwise, build a layout chunk with the size and alignment of
588 // the declaration.
589 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
13
Taking false branch
590 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
591 continue;
592 }
593
594 QualType VT = getCaptureFieldType(*CGF, CI);
14
Forming reference to null pointer
595
596 // If we have a lifetime qualifier, honor it for capture purposes.
597 // That includes *not* copying it if it's __unsafe_unretained.
598 Qualifiers::ObjCLifetime lifetime = VT.getObjCLifetime();
599 if (lifetime) {
600 switch (lifetime) {
601 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 601)
;
602 case Qualifiers::OCL_ExplicitNone:
603 case Qualifiers::OCL_Autoreleasing:
604 break;
605
606 case Qualifiers::OCL_Strong:
607 case Qualifiers::OCL_Weak:
608 info.NeedsCopyDispose = true;
609 }
610
611 // Block pointers require copy/dispose. So do Objective-C pointers.
612 } else if (VT->isObjCRetainableType()) {
613 // But honor the inert __unsafe_unretained qualifier, which doesn't
614 // actually make it into the type system.
615 if (VT->isObjCInertUnsafeUnretainedType()) {
616 lifetime = Qualifiers::OCL_ExplicitNone;
617 } else {
618 info.NeedsCopyDispose = true;
619 // used for mrr below.
620 lifetime = Qualifiers::OCL_Strong;
621 }
622
623 // So do types that require non-trivial copy construction.
624 } else if (CI.hasCopyExpr()) {
625 info.NeedsCopyDispose = true;
626 info.HasCXXObject = true;
627 if (!VT->getAsCXXRecordDecl()->isExternallyVisible())
628 info.CapturesNonExternalType = true;
629
630 // So do C structs that require non-trivial copy construction or
631 // destruction.
632 } else if (VT.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct ||
633 VT.isDestructedType() == QualType::DK_nontrivial_c_struct) {
634 info.NeedsCopyDispose = true;
635
636 // And so do types with destructors.
637 } else if (CGM.getLangOpts().CPlusPlus) {
638 if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
639 if (!record->hasTrivialDestructor()) {
640 info.HasCXXObject = true;
641 info.NeedsCopyDispose = true;
642 if (!record->isExternallyVisible())
643 info.CapturesNonExternalType = true;
644 }
645 }
646 }
647
648 CharUnits size = C.getTypeSizeInChars(VT);
649 CharUnits align = C.getDeclAlign(variable);
650
651 maxFieldAlign = std::max(maxFieldAlign, align);
652
653 llvm::Type *llvmType =
654 CGM.getTypes().ConvertTypeForMem(VT);
655
656 layout.push_back(
657 BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
658 }
659
660 // If that was everything, we're done here.
661 if (layout.empty()) {
662 info.StructureType =
663 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
664 info.CanBeGlobal = true;
665 return;
666 }
667
668 // Sort the layout by alignment. We have to use a stable sort here
669 // to get reproducible results. There should probably be an
670 // llvm::array_pod_stable_sort.
671 std::stable_sort(layout.begin(), layout.end());
672
673 // Needed for blocks layout info.
674 info.BlockHeaderForcedGapOffset = info.BlockSize;
675 info.BlockHeaderForcedGapSize = CharUnits::Zero();
676
677 CharUnits &blockSize = info.BlockSize;
678 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
679
680 // Assuming that the first byte in the header is maximally aligned,
681 // get the alignment of the first byte following the header.
682 CharUnits endAlign = getLowBit(blockSize);
683
684 // If the end of the header isn't satisfactorily aligned for the
685 // maximum thing, look for things that are okay with the header-end
686 // alignment, and keep appending them until we get something that's
687 // aligned right. This algorithm is only guaranteed optimal if
688 // that condition is satisfied at some point; otherwise we can get
689 // things like:
690 // header // next byte has alignment 4
691 // something_with_size_5; // next byte has alignment 1
692 // something_with_alignment_8;
693 // which has 7 bytes of padding, as opposed to the naive solution
694 // which might have less (?).
695 if (endAlign < maxFieldAlign) {
696 SmallVectorImpl<BlockLayoutChunk>::iterator
697 li = layout.begin() + 1, le = layout.end();
698
699 // Look for something that the header end is already
700 // satisfactorily aligned for.
701 for (; li != le && endAlign < li->Alignment; ++li)
702 ;
703
704 // If we found something that's naturally aligned for the end of
705 // the header, keep adding things...
706 if (li != le) {
707 SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
708 for (; li != le; ++li) {
709 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 709, __PRETTY_FUNCTION__))
;
710
711 li->setIndex(info, elementTypes.size(), blockSize);
712 elementTypes.push_back(li->Type);
713 blockSize += li->Size;
714 endAlign = getLowBit(blockSize);
715
716 // ...until we get to the alignment of the maximum field.
717 if (endAlign >= maxFieldAlign) {
718 break;
719 }
720 }
721 // Don't re-append everything we just appended.
722 layout.erase(first, li);
723 }
724 }
725
726 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 726, __PRETTY_FUNCTION__))
;
727
728 // At this point, we just have to add padding if the end align still
729 // isn't aligned right.
730 if (endAlign < maxFieldAlign) {
731 CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
732 CharUnits padding = newBlockSize - blockSize;
733
734 // If we haven't yet added any fields, remember that there was an
735 // initial gap; this need to go into the block layout bit map.
736 if (blockSize == info.BlockHeaderForcedGapOffset) {
737 info.BlockHeaderForcedGapSize = padding;
738 }
739
740 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
741 padding.getQuantity()));
742 blockSize = newBlockSize;
743 endAlign = getLowBit(blockSize); // might be > maxFieldAlign
744 }
745
746 assert(endAlign >= maxFieldAlign)((endAlign >= maxFieldAlign) ? static_cast<void> (0)
: __assert_fail ("endAlign >= maxFieldAlign", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 746, __PRETTY_FUNCTION__))
;
747 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 747, __PRETTY_FUNCTION__))
;
748 // Slam everything else on now. This works because they have
749 // strictly decreasing alignment and we expect that size is always a
750 // multiple of alignment.
751 for (SmallVectorImpl<BlockLayoutChunk>::iterator
752 li = layout.begin(), le = layout.end(); li != le; ++li) {
753 if (endAlign < li->Alignment) {
754 // size may not be multiple of alignment. This can only happen with
755 // an over-aligned variable. We will be adding a padding field to
756 // make the size be multiple of alignment.
757 CharUnits padding = li->Alignment - endAlign;
758 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
759 padding.getQuantity()));
760 blockSize += padding;
761 endAlign = getLowBit(blockSize);
762 }
763 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 763, __PRETTY_FUNCTION__))
;
764 li->setIndex(info, elementTypes.size(), blockSize);
765 elementTypes.push_back(li->Type);
766 blockSize += li->Size;
767 endAlign = getLowBit(blockSize);
768 }
769
770 info.StructureType =
771 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
772}
773
774/// Enter the scope of a block. This should be run at the entrance to
775/// a full-expression so that the block's cleanups are pushed at the
776/// right place in the stack.
777static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
778 assert(CGF.HaveInsertPoint())((CGF.HaveInsertPoint()) ? static_cast<void> (0) : __assert_fail
("CGF.HaveInsertPoint()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 778, __PRETTY_FUNCTION__))
;
779
780 // Allocate the block info and place it at the head of the list.
781 CGBlockInfo &blockInfo =
782 *new CGBlockInfo(block, CGF.CurFn->getName());
783 blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
784 CGF.FirstBlockInfo = &blockInfo;
785
786 // Compute information about the layout, etc., of this block,
787 // pushing cleanups as necessary.
788 computeBlockInfo(CGF.CGM, &CGF, blockInfo);
789
790 // Nothing else to do if it can be global.
791 if (blockInfo.CanBeGlobal) return;
792
793 // Make the allocation for the block.
794 blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
795 blockInfo.BlockAlign, "block");
796
797 // If there are cleanups to emit, enter them (but inactive).
798 if (!blockInfo.NeedsCopyDispose) return;
799
800 // Walk through the captures (in order) and find the ones not
801 // captured by constant.
802 for (const auto &CI : block->captures()) {
803 // Ignore __block captures; there's nothing special in the
804 // on-stack block that we need to do for them.
805 if (CI.isByRef()) continue;
806
807 // Ignore variables that are constant-captured.
808 const VarDecl *variable = CI.getVariable();
809 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
810 if (capture.isConstant()) continue;
811
812 // Ignore objects that aren't destructed.
813 QualType VT = getCaptureFieldType(CGF, CI);
814 QualType::DestructionKind dtorKind = VT.isDestructedType();
815 if (dtorKind == QualType::DK_none) continue;
816
817 CodeGenFunction::Destroyer *destroyer;
818
819 // Block captures count as local values and have imprecise semantics.
820 // They also can't be arrays, so need to worry about that.
821 //
822 // For const-qualified captures, emit clang.arc.use to ensure the captured
823 // object doesn't get released while we are still depending on its validity
824 // within the block.
825 if (VT.isConstQualified() &&
826 VT.getObjCLifetime() == Qualifiers::OCL_Strong &&
827 CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
828 assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&((CGF.CGM.getLangOpts().ObjCAutoRefCount && "expected ObjC ARC to be enabled"
) ? static_cast<void> (0) : __assert_fail ("CGF.CGM.getLangOpts().ObjCAutoRefCount && \"expected ObjC ARC to be enabled\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 829, __PRETTY_FUNCTION__))
829 "expected ObjC ARC to be enabled")((CGF.CGM.getLangOpts().ObjCAutoRefCount && "expected ObjC ARC to be enabled"
) ? static_cast<void> (0) : __assert_fail ("CGF.CGM.getLangOpts().ObjCAutoRefCount && \"expected ObjC ARC to be enabled\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 829, __PRETTY_FUNCTION__))
;
830 destroyer = CodeGenFunction::emitARCIntrinsicUse;
831 } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
832 destroyer = CodeGenFunction::destroyARCStrongImprecise;
833 } else {
834 destroyer = CGF.getDestroyer(dtorKind);
835 }
836
837 // GEP down to the address.
838 Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
839 capture.getIndex(),
840 capture.getOffset());
841
842 // We can use that GEP as the dominating IP.
843 if (!blockInfo.DominatingIP)
844 blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
845
846 CleanupKind cleanupKind = InactiveNormalCleanup;
847 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
848 if (useArrayEHCleanup)
849 cleanupKind = InactiveNormalAndEHCleanup;
850
851 CGF.pushDestroy(cleanupKind, addr, VT,
852 destroyer, useArrayEHCleanup);
853
854 // Remember where that cleanup was.
855 capture.setCleanup(CGF.EHStack.stable_begin());
856 }
857}
858
859/// Enter a full-expression with a non-trivial number of objects to
860/// clean up. This is in this file because, at the moment, the only
861/// kind of cleanup object is a BlockDecl*.
862void CodeGenFunction::enterNonTrivialFullExpression(const ExprWithCleanups *E) {
863 assert(E->getNumObjects() != 0)((E->getNumObjects() != 0) ? static_cast<void> (0) :
__assert_fail ("E->getNumObjects() != 0", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 863, __PRETTY_FUNCTION__))
;
864 for (const ExprWithCleanups::CleanupObject &C : E->getObjects())
865 enterBlockScope(*this, C);
866}
867
868/// Find the layout for the given block in a linked list and remove it.
869static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head,
870 const BlockDecl *block) {
871 while (true) {
872 assert(head && *head)((head && *head) ? static_cast<void> (0) : __assert_fail
("head && *head", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 872, __PRETTY_FUNCTION__))
;
873 CGBlockInfo *cur = *head;
874
875 // If this is the block we're looking for, splice it out of the list.
876 if (cur->getBlockDecl() == block) {
877 *head = cur->NextBlockInfo;
878 return cur;
879 }
880
881 head = &cur->NextBlockInfo;
882 }
883}
884
885/// Destroy a chain of block layouts.
886void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) {
887 assert(head && "destroying an empty chain")((head && "destroying an empty chain") ? static_cast<
void> (0) : __assert_fail ("head && \"destroying an empty chain\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 887, __PRETTY_FUNCTION__))
;
888 do {
889 CGBlockInfo *cur = head;
890 head = cur->NextBlockInfo;
891 delete cur;
892 } while (head != nullptr);
893}
894
895/// Emit a block literal expression in the current function.
896llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
897 // If the block has no captures, we won't have a pre-computed
898 // layout for it.
899 if (!blockExpr->getBlockDecl()->hasCaptures()) {
900 // The block literal is emitted as a global variable, and the block invoke
901 // function has to be extracted from its initializer.
902 if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
903 return Block;
904 }
905 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
906 computeBlockInfo(CGM, this, blockInfo);
907 blockInfo.BlockExpression = blockExpr;
908 return EmitBlockLiteral(blockInfo);
909 }
910
911 // Find the block info for this block and take ownership of it.
912 std::unique_ptr<CGBlockInfo> blockInfo;
913 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
914 blockExpr->getBlockDecl()));
915
916 blockInfo->BlockExpression = blockExpr;
917 return EmitBlockLiteral(*blockInfo);
918}
919
920llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
921 bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
922 auto GenVoidPtrTy =
923 IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
924 LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
925 auto GenVoidPtrSize = CharUnits::fromQuantity(
926 CGM.getTarget().getPointerWidth(
927 CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
928 8);
929 // Using the computed layout, generate the actual block function.
930 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
931 CodeGenFunction BlockCGF{CGM, true};
932 BlockCGF.SanOpts = SanOpts;
933 auto *InvokeFn = BlockCGF.GenerateBlockFunction(
934 CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
935 auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
936
937 // If there is nothing to capture, we can emit this as a global block.
938 if (blockInfo.CanBeGlobal)
939 return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
940
941 // Otherwise, we have to emit this as a local block.
942
943 Address blockAddr = blockInfo.LocalAddress;
944 assert(blockAddr.isValid() && "block has no address!")((blockAddr.isValid() && "block has no address!") ? static_cast
<void> (0) : __assert_fail ("blockAddr.isValid() && \"block has no address!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 944, __PRETTY_FUNCTION__))
;
945
946 llvm::Constant *isa;
947 llvm::Constant *descriptor;
948 BlockFlags flags;
949 if (!IsOpenCL) {
950 // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
951 // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
952 // block just returns the original block and releasing it is a no-op.
953 llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
954 ? CGM.getNSConcreteGlobalBlock()
955 : CGM.getNSConcreteStackBlock();
956 isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
957
958 // Build the block descriptor.
959 descriptor = buildBlockDescriptor(CGM, blockInfo);
960
961 // Compute the initial on-stack block flags.
962 flags = BLOCK_HAS_SIGNATURE;
963 if (blockInfo.HasCapturedVariableLayout)
964 flags |= BLOCK_HAS_EXTENDED_LAYOUT;
965 if (blockInfo.needsCopyDisposeHelpers())
966 flags |= BLOCK_HAS_COPY_DISPOSE;
967 if (blockInfo.HasCXXObject)
968 flags |= BLOCK_HAS_CXX_OBJ;
969 if (blockInfo.UsesStret)
970 flags |= BLOCK_USE_STRET;
971 if (blockInfo.getBlockDecl()->doesNotEscape())
972 flags |= BLOCK_IS_NOESCAPE | BLOCK_IS_GLOBAL;
973 }
974
975 auto projectField =
976 [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
977 return Builder.CreateStructGEP(blockAddr, index, offset, name);
978 };
979 auto storeField =
980 [&](llvm::Value *value, unsigned index, CharUnits offset,
981 const Twine &name) {
982 Builder.CreateStore(value, projectField(index, offset, name));
983 };
984
985 // Initialize the block header.
986 {
987 // We assume all the header fields are densely packed.
988 unsigned index = 0;
989 CharUnits offset;
990 auto addHeaderField =
991 [&](llvm::Value *value, CharUnits size, const Twine &name) {
992 storeField(value, index, offset, name);
993 offset += size;
994 index++;
995 };
996
997 if (!IsOpenCL) {
998 addHeaderField(isa, getPointerSize(), "block.isa");
999 addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1000 getIntSize(), "block.flags");
1001 addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1002 "block.reserved");
1003 } else {
1004 addHeaderField(
1005 llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1006 getIntSize(), "block.size");
1007 addHeaderField(
1008 llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1009 getIntSize(), "block.align");
1010 }
1011 addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1012 if (!IsOpenCL)
1013 addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1014 else if (auto *Helper =
1015 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1016 for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1017 addHeaderField(
1018 I.first,
1019 CharUnits::fromQuantity(
1020 CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1021 I.second);
1022 }
1023 }
1024 }
1025
1026 // Finally, capture all the values into the block.
1027 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1028
1029 // First, 'this'.
1030 if (blockDecl->capturesCXXThis()) {
1031 Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
1032 "block.captured-this.addr");
1033 Builder.CreateStore(LoadCXXThis(), addr);
1034 }
1035
1036 // Next, captured variables.
1037 for (const auto &CI : blockDecl->captures()) {
1038 const VarDecl *variable = CI.getVariable();
1039 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1040
1041 // Ignore constant captures.
1042 if (capture.isConstant()) continue;
1043
1044 QualType type = capture.fieldType();
1045
1046 // This will be a [[type]]*, except that a byref entry will just be
1047 // an i8**.
1048 Address blockField =
1049 projectField(capture.getIndex(), capture.getOffset(), "block.captured");
1050
1051 // Compute the address of the thing we're going to move into the
1052 // block literal.
1053 Address src = Address::invalid();
1054
1055 if (blockDecl->isConversionFromLambda()) {
1056 // The lambda capture in a lambda's conversion-to-block-pointer is
1057 // special; we'll simply emit it directly.
1058 src = Address::invalid();
1059 } else if (CI.isEscapingByref()) {
1060 if (BlockInfo && CI.isNested()) {
1061 // We need to use the capture from the enclosing block.
1062 const CGBlockInfo::Capture &enclosingCapture =
1063 BlockInfo->getCapture(variable);
1064
1065 // This is a [[type]]*, except that a byref entry will just be an i8**.
1066 src = Builder.CreateStructGEP(LoadBlockStruct(),
1067 enclosingCapture.getIndex(),
1068 enclosingCapture.getOffset(),
1069 "block.capture.addr");
1070 } else {
1071 auto I = LocalDeclMap.find(variable);
1072 assert(I != LocalDeclMap.end())((I != LocalDeclMap.end()) ? static_cast<void> (0) : __assert_fail
("I != LocalDeclMap.end()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1072, __PRETTY_FUNCTION__))
;
1073 src = I->second;
1074 }
1075 } else {
1076 DeclRefExpr declRef(const_cast<VarDecl *>(variable),
1077 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1078 type.getNonReferenceType(), VK_LValue,
1079 SourceLocation());
1080 src = EmitDeclRefLValue(&declRef).getAddress();
1081 };
1082
1083 // For byrefs, we just write the pointer to the byref struct into
1084 // the block field. There's no need to chase the forwarding
1085 // pointer at this point, since we're building something that will
1086 // live a shorter life than the stack byref anyway.
1087 if (CI.isEscapingByref()) {
1088 // Get a void* that points to the byref struct.
1089 llvm::Value *byrefPointer;
1090 if (CI.isNested())
1091 byrefPointer = Builder.CreateLoad(src, "byref.capture");
1092 else
1093 byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1094
1095 // Write that void* into the capture field.
1096 Builder.CreateStore(byrefPointer, blockField);
1097
1098 // If we have a copy constructor, evaluate that into the block field.
1099 } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1100 if (blockDecl->isConversionFromLambda()) {
1101 // If we have a lambda conversion, emit the expression
1102 // directly into the block instead.
1103 AggValueSlot Slot =
1104 AggValueSlot::forAddr(blockField, Qualifiers(),
1105 AggValueSlot::IsDestructed,
1106 AggValueSlot::DoesNotNeedGCBarriers,
1107 AggValueSlot::IsNotAliased,
1108 AggValueSlot::DoesNotOverlap);
1109 EmitAggExpr(copyExpr, Slot);
1110 } else {
1111 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1112 }
1113
1114 // If it's a reference variable, copy the reference into the block field.
1115 } else if (type->isReferenceType()) {
1116 Builder.CreateStore(src.getPointer(), blockField);
1117
1118 // If type is const-qualified, copy the value into the block field.
1119 } else if (type.isConstQualified() &&
1120 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1121 CGM.getCodeGenOpts().OptimizationLevel != 0) {
1122 llvm::Value *value = Builder.CreateLoad(src, "captured");
1123 Builder.CreateStore(value, blockField);
1124
1125 // If this is an ARC __strong block-pointer variable, don't do a
1126 // block copy.
1127 //
1128 // TODO: this can be generalized into the normal initialization logic:
1129 // we should never need to do a block-copy when initializing a local
1130 // variable, because the local variable's lifetime should be strictly
1131 // contained within the stack block's.
1132 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1133 type->isBlockPointerType()) {
1134 // Load the block and do a simple retain.
1135 llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1136 value = EmitARCRetainNonBlock(value);
1137
1138 // Do a primitive store to the block field.
1139 Builder.CreateStore(value, blockField);
1140
1141 // Otherwise, fake up a POD copy into the block field.
1142 } else {
1143 // Fake up a new variable so that EmitScalarInit doesn't think
1144 // we're referring to the variable in its own initializer.
1145 ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1146 ImplicitParamDecl::Other);
1147
1148 // We use one of these or the other depending on whether the
1149 // reference is nested.
1150 DeclRefExpr declRef(const_cast<VarDecl *>(variable),
1151 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1152 type, VK_LValue, SourceLocation());
1153
1154 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1155 &declRef, VK_RValue);
1156 // FIXME: Pass a specific location for the expr init so that the store is
1157 // attributed to a reasonable location - otherwise it may be attributed to
1158 // locations of subexpressions in the initialization.
1159 EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1160 MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1161 /*captured by init*/ false);
1162 }
1163
1164 // Activate the cleanup if layout pushed one.
1165 if (!CI.isByRef()) {
1166 EHScopeStack::stable_iterator cleanup = capture.getCleanup();
1167 if (cleanup.isValid())
1168 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1169 }
1170 }
1171
1172 // Cast to the converted block-pointer type, which happens (somewhat
1173 // unfortunately) to be a pointer to function type.
1174 llvm::Value *result = Builder.CreatePointerCast(
1175 blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1176
1177 if (IsOpenCL) {
1178 CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1179 result);
1180 }
1181
1182 return result;
1183}
1184
1185
1186llvm::Type *CodeGenModule::getBlockDescriptorType() {
1187 if (BlockDescriptorType)
1188 return BlockDescriptorType;
1189
1190 llvm::Type *UnsignedLongTy =
1191 getTypes().ConvertType(getContext().UnsignedLongTy);
1192
1193 // struct __block_descriptor {
1194 // unsigned long reserved;
1195 // unsigned long block_size;
1196 //
1197 // // later, the following will be added
1198 //
1199 // struct {
1200 // void (*copyHelper)();
1201 // void (*copyHelper)();
1202 // } helpers; // !!! optional
1203 //
1204 // const char *signature; // the block signature
1205 // const char *layout; // reserved
1206 // };
1207 BlockDescriptorType = llvm::StructType::create(
1208 "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1209
1210 // Now form a pointer to that.
1211 unsigned AddrSpace = 0;
1212 if (getLangOpts().OpenCL)
1213 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1214 BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1215 return BlockDescriptorType;
1216}
1217
1218llvm::Type *CodeGenModule::getGenericBlockLiteralType() {
1219 if (GenericBlockLiteralType)
1220 return GenericBlockLiteralType;
1221
1222 llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1223
1224 if (getLangOpts().OpenCL) {
1225 // struct __opencl_block_literal_generic {
1226 // int __size;
1227 // int __align;
1228 // __generic void *__invoke;
1229 // /* custom fields */
1230 // };
1231 SmallVector<llvm::Type *, 8> StructFields(
1232 {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1233 if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1234 for (auto I : Helper->getCustomFieldTypes())
1235 StructFields.push_back(I);
1236 }
1237 GenericBlockLiteralType = llvm::StructType::create(
1238 StructFields, "struct.__opencl_block_literal_generic");
1239 } else {
1240 // struct __block_literal_generic {
1241 // void *__isa;
1242 // int __flags;
1243 // int __reserved;
1244 // void (*__invoke)(void *);
1245 // struct __block_descriptor *__descriptor;
1246 // };
1247 GenericBlockLiteralType =
1248 llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1249 IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1250 }
1251
1252 return GenericBlockLiteralType;
1253}
1254
1255RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E,
1256 ReturnValueSlot ReturnValue) {
1257 const BlockPointerType *BPT =
1258 E->getCallee()->getType()->getAs<BlockPointerType>();
1259
1260 llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1261
1262 // Get a pointer to the generic block literal.
1263 // For OpenCL we generate generic AS void ptr to be able to reuse the same
1264 // block definition for blocks with captures generated as private AS local
1265 // variables and without captures generated as global AS program scope
1266 // variables.
1267 unsigned AddrSpace = 0;
1268 if (getLangOpts().OpenCL)
1269 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1270
1271 llvm::Type *BlockLiteralTy =
1272 llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1273
1274 // Bitcast the callee to a block literal.
1275 BlockPtr =
1276 Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1277
1278 // Get the function pointer from the literal.
1279 llvm::Value *FuncPtr =
1280 Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr,
1281 CGM.getLangOpts().OpenCL ? 2 : 3);
1282
1283 // Add the block literal.
1284 CallArgList Args;
1285
1286 QualType VoidPtrQualTy = getContext().VoidPtrTy;
1287 llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1288 if (getLangOpts().OpenCL) {
1289 GenericVoidPtrTy = CGM.getOpenCLRuntime().getGenericVoidPointerType();
1290 VoidPtrQualTy =
1291 getContext().getPointerType(getContext().getAddrSpaceQualType(
1292 getContext().VoidTy, LangAS::opencl_generic));
1293 }
1294
1295 BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1296 Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1297
1298 QualType FnType = BPT->getPointeeType();
1299
1300 // And the rest of the arguments.
1301 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1302
1303 // Load the function.
1304 llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1305
1306 const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1307 const CGFunctionInfo &FnInfo =
1308 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1309
1310 // Cast the function pointer to the right type.
1311 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1312
1313 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1314 Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1315
1316 // Prepare the callee.
1317 CGCallee Callee(CGCalleeInfo(), Func);
1318
1319 // And call the block.
1320 return EmitCall(FnInfo, Callee, ReturnValue, Args);
1321}
1322
1323Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable) {
1324 assert(BlockInfo && "evaluating block ref without block information?")((BlockInfo && "evaluating block ref without block information?"
) ? static_cast<void> (0) : __assert_fail ("BlockInfo && \"evaluating block ref without block information?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1324, __PRETTY_FUNCTION__))
;
1325 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1326
1327 // Handle constant captures.
1328 if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1329
1330 Address addr =
1331 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1332 capture.getOffset(), "block.capture.addr");
1333
1334 if (variable->isEscapingByref()) {
1335 // addr should be a void** right now. Load, then cast the result
1336 // to byref*.
1337
1338 auto &byrefInfo = getBlockByrefInfo(variable);
1339 addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1340
1341 auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1342 addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1343
1344 addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1345 variable->getName());
1346 }
1347
1348 assert((!variable->isNonEscapingByref() ||(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1351, __PRETTY_FUNCTION__))
1349 capture.fieldType()->isReferenceType()) &&(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1351, __PRETTY_FUNCTION__))
1350 "the capture field of a non-escaping variable should have a "(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1351, __PRETTY_FUNCTION__))
1351 "reference type")(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1351, __PRETTY_FUNCTION__))
;
1352 if (capture.fieldType()->isReferenceType())
1353 addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1354
1355 return addr;
1356}
1357
1358void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
1359 llvm::Constant *Addr) {
1360 bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1361 (void)Ok;
1362 assert(Ok && "Trying to replace an already-existing global block!")((Ok && "Trying to replace an already-existing global block!"
) ? static_cast<void> (0) : __assert_fail ("Ok && \"Trying to replace an already-existing global block!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1362, __PRETTY_FUNCTION__))
;
1363}
1364
1365llvm::Constant *
1366CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
1367 StringRef Name) {
1368 if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1
Assuming 'Block' is null
2
Taking false branch
1369 return Block;
1370
1371 CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1372 blockInfo.BlockExpression = BE;
1373
1374 // Compute information about the layout, etc., of this block.
1375 computeBlockInfo(*this, nullptr, blockInfo);
3
Passing null pointer value via 2nd parameter 'CGF'
4
Calling 'computeBlockInfo'
1376
1377 // Using that metadata, generate the actual block function.
1378 {
1379 CodeGenFunction::DeclMapTy LocalDeclMap;
1380 CodeGenFunction(*this).GenerateBlockFunction(
1381 GlobalDecl(), blockInfo, LocalDeclMap,
1382 /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1383 }
1384
1385 return getAddrOfGlobalBlockIfEmitted(BE);
1386}
1387
1388static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1389 const CGBlockInfo &blockInfo,
1390 llvm::Constant *blockFn) {
1391 assert(blockInfo.CanBeGlobal)((blockInfo.CanBeGlobal) ? static_cast<void> (0) : __assert_fail
("blockInfo.CanBeGlobal", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1391, __PRETTY_FUNCTION__))
;
1392 // Callers should detect this case on their own: calling this function
1393 // generally requires computing layout information, which is a waste of time
1394 // if we've already emitted this block.
1395 assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&((!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression
) && "Refusing to re-emit a global block.") ? static_cast
<void> (0) : __assert_fail ("!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) && \"Refusing to re-emit a global block.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1396, __PRETTY_FUNCTION__))
1396 "Refusing to re-emit a global block.")((!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression
) && "Refusing to re-emit a global block.") ? static_cast
<void> (0) : __assert_fail ("!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) && \"Refusing to re-emit a global block.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1396, __PRETTY_FUNCTION__))
;
1397
1398 // Generate the constants for the block literal initializer.
1399 ConstantInitBuilder builder(CGM);
1400 auto fields = builder.beginStruct();
1401
1402 bool IsOpenCL = CGM.getLangOpts().OpenCL;
1403 bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1404 if (!IsOpenCL) {
1405 // isa
1406 if (IsWindows)
1407 fields.addNullPointer(CGM.Int8PtrPtrTy);
1408 else
1409 fields.add(CGM.getNSConcreteGlobalBlock());
1410
1411 // __flags
1412 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE;
1413 if (blockInfo.UsesStret)
1414 flags |= BLOCK_USE_STRET;
1415
1416 fields.addInt(CGM.IntTy, flags.getBitMask());
1417
1418 // Reserved
1419 fields.addInt(CGM.IntTy, 0);
1420 } else {
1421 fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1422 fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1423 }
1424
1425 // Function
1426 fields.add(blockFn);
1427
1428 if (!IsOpenCL) {
1429 // Descriptor
1430 fields.add(buildBlockDescriptor(CGM, blockInfo));
1431 } else if (auto *Helper =
1432 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1433 for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1434 fields.add(I);
1435 }
1436 }
1437
1438 unsigned AddrSpace = 0;
1439 if (CGM.getContext().getLangOpts().OpenCL)
1440 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
1441
1442 llvm::Constant *literal = fields.finishAndCreateGlobal(
1443 "__block_literal_global", blockInfo.BlockAlign,
1444 /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1445
1446 // Windows does not allow globals to be initialised to point to globals in
1447 // different DLLs. Any such variables must run code to initialise them.
1448 if (IsWindows) {
1449 auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1450 {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1451 &CGM.getModule());
1452 llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1453 Init));
1454 b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1455 b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1456 b.CreateRetVoid();
1457 // We can't use the normal LLVM global initialisation array, because we
1458 // need to specify that this runs early in library initialisation.
1459 auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1460 /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1461 Init, ".block_isa_init_ptr");
1462 InitVar->setSection(".CRT$XCLa");
1463 CGM.addUsedGlobal(InitVar);
1464 }
1465
1466 // Return a constant of the appropriately-casted type.
1467 llvm::Type *RequiredType =
1468 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1469 llvm::Constant *Result =
1470 llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1471 CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1472 if (CGM.getContext().getLangOpts().OpenCL)
1473 CGM.getOpenCLRuntime().recordBlockInfo(
1474 blockInfo.BlockExpression,
1475 cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1476 return Result;
1477}
1478
1479void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,
1480 unsigned argNum,
1481 llvm::Value *arg) {
1482 assert(BlockInfo && "not emitting prologue of block invocation function?!")((BlockInfo && "not emitting prologue of block invocation function?!"
) ? static_cast<void> (0) : __assert_fail ("BlockInfo && \"not emitting prologue of block invocation function?!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1482, __PRETTY_FUNCTION__))
;
1483
1484 // Allocate a stack slot like for any local variable to guarantee optimal
1485 // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1486 Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1487 Builder.CreateStore(arg, alloc);
1488 if (CGDebugInfo *DI = getDebugInfo()) {
1489 if (CGM.getCodeGenOpts().getDebugInfo() >=
1490 codegenoptions::LimitedDebugInfo) {
1491 DI->setLocation(D->getLocation());
1492 DI->EmitDeclareOfBlockLiteralArgVariable(
1493 *BlockInfo, D->getName(), argNum,
1494 cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1495 }
1496 }
1497
1498 SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1499 ApplyDebugLocation Scope(*this, StartLoc);
1500
1501 // Instead of messing around with LocalDeclMap, just set the value
1502 // directly as BlockPointer.
1503 BlockPointer = Builder.CreatePointerCast(
1504 arg,
1505 BlockInfo->StructureType->getPointerTo(
1506 getContext().getLangOpts().OpenCL
1507 ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1508 : 0),
1509 "block");
1510}
1511
1512Address CodeGenFunction::LoadBlockStruct() {
1513 assert(BlockInfo && "not in a block invocation function!")((BlockInfo && "not in a block invocation function!")
? static_cast<void> (0) : __assert_fail ("BlockInfo && \"not in a block invocation function!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1513, __PRETTY_FUNCTION__))
;
1514 assert(BlockPointer && "no block pointer set!")((BlockPointer && "no block pointer set!") ? static_cast
<void> (0) : __assert_fail ("BlockPointer && \"no block pointer set!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1514, __PRETTY_FUNCTION__))
;
1515 return Address(BlockPointer, BlockInfo->BlockAlign);
1516}
1517
1518llvm::Function *
1519CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
1520 const CGBlockInfo &blockInfo,
1521 const DeclMapTy &ldm,
1522 bool IsLambdaConversionToBlock,
1523 bool BuildGlobalBlock) {
1524 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1525
1526 CurGD = GD;
1527
1528 CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1529
1530 BlockInfo = &blockInfo;
1531
1532 // Arrange for local static and local extern declarations to appear
1533 // to be local to this function as well, in case they're directly
1534 // referenced in a block.
1535 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1536 const auto *var = dyn_cast<VarDecl>(i->first);
1537 if (var && !var->hasLocalStorage())
1538 setAddrOfLocalVar(var, i->second);
1539 }
1540
1541 // Begin building the function declaration.
1542
1543 // Build the argument list.
1544 FunctionArgList args;
1545
1546 // The first argument is the block pointer. Just take it as a void*
1547 // and cast it later.
1548 QualType selfTy = getContext().VoidPtrTy;
1549
1550 // For OpenCL passed block pointer can be private AS local variable or
1551 // global AS program scope variable (for the case with and without captures).
1552 // Generic AS is used therefore to be able to accommodate both private and
1553 // generic AS in one implementation.
1554 if (getLangOpts().OpenCL)
1555 selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1556 getContext().VoidTy, LangAS::opencl_generic));
1557
1558 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1559
1560 ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1561 SourceLocation(), II, selfTy,
1562 ImplicitParamDecl::ObjCSelf);
1563 args.push_back(&SelfDecl);
1564
1565 // Now add the rest of the parameters.
1566 args.append(blockDecl->param_begin(), blockDecl->param_end());
1567
1568 // Create the function declaration.
1569 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1570 const CGFunctionInfo &fnInfo =
1571 CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1572 if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1573 blockInfo.UsesStret = true;
1574
1575 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1576
1577 StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1578 llvm::Function *fn = llvm::Function::Create(
1579 fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1580 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1581
1582 if (BuildGlobalBlock) {
1583 auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1584 ? CGM.getOpenCLRuntime().getGenericVoidPointerType()
1585 : VoidPtrTy;
1586 buildGlobalBlock(CGM, blockInfo,
1587 llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1588 }
1589
1590 // Begin generating the function.
1591 StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1592 blockDecl->getLocation(),
1593 blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1594
1595 // Okay. Undo some of what StartFunction did.
1596
1597 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1598 // won't delete the dbg.declare intrinsics for captured variables.
1599 llvm::Value *BlockPointerDbgLoc = BlockPointer;
1600 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1601 // Allocate a stack slot for it, so we can point the debugger to it
1602 Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1603 getPointerAlign(),
1604 "block.addr");
1605 // Set the DebugLocation to empty, so the store is recognized as a
1606 // frame setup instruction by llvm::DwarfDebug::beginFunction().
1607 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1608 Builder.CreateStore(BlockPointer, Alloca);
1609 BlockPointerDbgLoc = Alloca.getPointer();
1610 }
1611
1612 // If we have a C++ 'this' reference, go ahead and force it into
1613 // existence now.
1614 if (blockDecl->capturesCXXThis()) {
1615 Address addr =
1616 Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1617 blockInfo.CXXThisOffset, "block.captured-this");
1618 CXXThisValue = Builder.CreateLoad(addr, "this");
1619 }
1620
1621 // Also force all the constant captures.
1622 for (const auto &CI : blockDecl->captures()) {
1623 const VarDecl *variable = CI.getVariable();
1624 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1625 if (!capture.isConstant()) continue;
1626
1627 CharUnits align = getContext().getDeclAlign(variable);
1628 Address alloca =
1629 CreateMemTemp(variable->getType(), align, "block.captured-const");
1630
1631 Builder.CreateStore(capture.getConstant(), alloca);
1632
1633 setAddrOfLocalVar(variable, alloca);
1634 }
1635
1636 // Save a spot to insert the debug information for all the DeclRefExprs.
1637 llvm::BasicBlock *entry = Builder.GetInsertBlock();
1638 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1639 --entry_ptr;
1640
1641 if (IsLambdaConversionToBlock)
1642 EmitLambdaBlockInvokeBody();
1643 else {
1644 PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1645 incrementProfileCounter(blockDecl->getBody());
1646 EmitStmt(blockDecl->getBody());
1647 }
1648
1649 // Remember where we were...
1650 llvm::BasicBlock *resume = Builder.GetInsertBlock();
1651
1652 // Go back to the entry.
1653 ++entry_ptr;
1654 Builder.SetInsertPoint(entry, entry_ptr);
1655
1656 // Emit debug information for all the DeclRefExprs.
1657 // FIXME: also for 'this'
1658 if (CGDebugInfo *DI = getDebugInfo()) {
1659 for (const auto &CI : blockDecl->captures()) {
1660 const VarDecl *variable = CI.getVariable();
1661 DI->EmitLocation(Builder, variable->getLocation());
1662
1663 if (CGM.getCodeGenOpts().getDebugInfo() >=
1664 codegenoptions::LimitedDebugInfo) {
1665 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1666 if (capture.isConstant()) {
1667 auto addr = LocalDeclMap.find(variable)->second;
1668 (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1669 Builder);
1670 continue;
1671 }
1672
1673 DI->EmitDeclareOfBlockDeclRefVariable(
1674 variable, BlockPointerDbgLoc, Builder, blockInfo,
1675 entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1676 }
1677 }
1678 // Recover location if it was changed in the above loop.
1679 DI->EmitLocation(Builder,
1680 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1681 }
1682
1683 // And resume where we left off.
1684 if (resume == nullptr)
1685 Builder.ClearInsertionPoint();
1686 else
1687 Builder.SetInsertPoint(resume);
1688
1689 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1690
1691 return fn;
1692}
1693
1694static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1695computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1696 const LangOptions &LangOpts) {
1697 if (CI.getCopyExpr()) {
1698 assert(!CI.isByRef())((!CI.isByRef()) ? static_cast<void> (0) : __assert_fail
("!CI.isByRef()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1698, __PRETTY_FUNCTION__))
;
1699 // don't bother computing flags
1700 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1701 }
1702 BlockFieldFlags Flags;
1703 if (CI.isEscapingByref()) {
1704 Flags = BLOCK_FIELD_IS_BYREF;
1705 if (T.isObjCGCWeak())
1706 Flags |= BLOCK_FIELD_IS_WEAK;
1707 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1708 }
1709
1710 Flags = BLOCK_FIELD_IS_OBJECT;
1711 bool isBlockPointer = T->isBlockPointerType();
1712 if (isBlockPointer)
1713 Flags = BLOCK_FIELD_IS_BLOCK;
1714
1715 switch (T.isNonTrivialToPrimitiveCopy()) {
1716 case QualType::PCK_Struct:
1717 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1718 BlockFieldFlags());
1719 case QualType::PCK_ARCWeak:
1720 // We need to register __weak direct captures with the runtime.
1721 return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1722 case QualType::PCK_ARCStrong:
1723 // We need to retain the copied value for __strong direct captures.
1724 // If it's a block pointer, we have to copy the block and assign that to
1725 // the destination pointer, so we might as well use _Block_object_assign.
1726 // Otherwise we can avoid that.
1727 return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1728 : BlockCaptureEntityKind::BlockObject,
1729 Flags);
1730 case QualType::PCK_Trivial:
1731 case QualType::PCK_VolatileTrivial: {
1732 if (!T->isObjCRetainableType())
1733 // For all other types, the memcpy is fine.
1734 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1735
1736 // Special rules for ARC captures:
1737 Qualifiers QS = T.getQualifiers();
1738
1739 // Non-ARC captures of retainable pointers are strong and
1740 // therefore require a call to _Block_object_assign.
1741 if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1742 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1743
1744 // Otherwise the memcpy is fine.
1745 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1746 }
1747 }
1748 llvm_unreachable("after exhaustive PrimitiveCopyKind switch")::llvm::llvm_unreachable_internal("after exhaustive PrimitiveCopyKind switch"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1748)
;
1749}
1750
1751static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1752computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1753 const LangOptions &LangOpts);
1754
1755/// Find the set of block captures that need to be explicitly copied or destroy.
1756static void findBlockCapturedManagedEntities(
1757 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1758 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1759 for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1760 const VarDecl *Variable = CI.getVariable();
1761 const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1762 if (Capture.isConstant())
1763 continue;
1764
1765 QualType VT = Capture.fieldType();
1766 auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1767 auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1768 if (CopyInfo.first != BlockCaptureEntityKind::None ||
1769 DisposeInfo.first != BlockCaptureEntityKind::None)
1770 ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1771 CopyInfo.second, DisposeInfo.second, CI,
1772 Capture);
1773 }
1774
1775 // Sort the captures by offset.
1776 llvm::sort(ManagedCaptures);
1777}
1778
1779namespace {
1780/// Release a __block variable.
1781struct CallBlockRelease final : EHScopeStack::Cleanup {
1782 Address Addr;
1783 BlockFieldFlags FieldFlags;
1784 bool LoadBlockVarAddr, CanThrow;
1785
1786 CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1787 bool CT)
1788 : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1789 CanThrow(CT) {}
1790
1791 void Emit(CodeGenFunction &CGF, Flags flags) override {
1792 llvm::Value *BlockVarAddr;
1793 if (LoadBlockVarAddr) {
1794 BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1795 BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1796 } else {
1797 BlockVarAddr = Addr.getPointer();
1798 }
1799
1800 CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1801 }
1802};
1803} // end anonymous namespace
1804
1805/// Check if \p T is a C++ class that has a destructor that can throw.
1806bool CodeGenFunction::cxxDestructorCanThrow(QualType T) {
1807 if (const auto *RD = T->getAsCXXRecordDecl())
1808 if (const CXXDestructorDecl *DD = RD->getDestructor())
1809 return DD->getType()->getAs<FunctionProtoType>()->canThrow();
1810 return false;
1811}
1812
1813// Return a string that has the information about a capture.
1814static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1815 CaptureStrKind StrKind,
1816 CharUnits BlockAlignment,
1817 CodeGenModule &CGM) {
1818 std::string Str;
1819 ASTContext &Ctx = CGM.getContext();
1820 const BlockDecl::Capture &CI = *E.CI;
1821 QualType CaptureTy = CI.getVariable()->getType();
1822
1823 BlockCaptureEntityKind Kind;
1824 BlockFieldFlags Flags;
1825
1826 // CaptureStrKind::Merged should be passed only when the operations and the
1827 // flags are the same for copy and dispose.
1828 assert((StrKind != CaptureStrKind::Merged ||(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1830, __PRETTY_FUNCTION__))
1829 (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1830, __PRETTY_FUNCTION__))
1830 "different operations and flags")(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1830, __PRETTY_FUNCTION__))
;
1831
1832 if (StrKind == CaptureStrKind::DisposeHelper) {
1833 Kind = E.DisposeKind;
1834 Flags = E.DisposeFlags;
1835 } else {
1836 Kind = E.CopyKind;
1837 Flags = E.CopyFlags;
1838 }
1839
1840 switch (Kind) {
1841 case BlockCaptureEntityKind::CXXRecord: {
1842 Str += "c";
1843 SmallString<256> TyStr;
1844 llvm::raw_svector_ostream Out(TyStr);
1845 CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1846 Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1847 break;
1848 }
1849 case BlockCaptureEntityKind::ARCWeak:
1850 Str += "w";
1851 break;
1852 case BlockCaptureEntityKind::ARCStrong:
1853 Str += "s";
1854 break;
1855 case BlockCaptureEntityKind::BlockObject: {
1856 const VarDecl *Var = CI.getVariable();
1857 unsigned F = Flags.getBitMask();
1858 if (F & BLOCK_FIELD_IS_BYREF) {
1859 Str += "r";
1860 if (F & BLOCK_FIELD_IS_WEAK)
1861 Str += "w";
1862 else {
1863 // If CaptureStrKind::Merged is passed, check both the copy expression
1864 // and the destructor.
1865 if (StrKind != CaptureStrKind::DisposeHelper) {
1866 if (Ctx.getBlockVarCopyInit(Var).canThrow())
1867 Str += "c";
1868 }
1869 if (StrKind != CaptureStrKind::CopyHelper) {
1870 if (CodeGenFunction::cxxDestructorCanThrow(CaptureTy))
1871 Str += "d";
1872 }
1873 }
1874 } else {
1875 assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value")(((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value"
) ? static_cast<void> (0) : __assert_fail ("(F & BLOCK_FIELD_IS_OBJECT) && \"unexpected flag value\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1875, __PRETTY_FUNCTION__))
;
1876 if (F == BLOCK_FIELD_IS_BLOCK)
1877 Str += "b";
1878 else
1879 Str += "o";
1880 }
1881 break;
1882 }
1883 case BlockCaptureEntityKind::NonTrivialCStruct: {
1884 bool IsVolatile = CaptureTy.isVolatileQualified();
1885 CharUnits Alignment =
1886 BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1887
1888 Str += "n";
1889 std::string FuncStr;
1890 if (StrKind == CaptureStrKind::DisposeHelper)
1891 FuncStr = CodeGenFunction::getNonTrivialDestructorStr(
1892 CaptureTy, Alignment, IsVolatile, Ctx);
1893 else
1894 // If CaptureStrKind::Merged is passed, use the copy constructor string.
1895 // It has all the information that the destructor string has.
1896 FuncStr = CodeGenFunction::getNonTrivialCopyConstructorStr(
1897 CaptureTy, Alignment, IsVolatile, Ctx);
1898 // The underscore is necessary here because non-trivial copy constructor
1899 // and destructor strings can start with a number.
1900 Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1901 break;
1902 }
1903 case BlockCaptureEntityKind::None:
1904 break;
1905 }
1906
1907 return Str;
1908}
1909
1910static std::string getCopyDestroyHelperFuncName(
1911 const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1912 CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1913 assert((StrKind == CaptureStrKind::CopyHelper ||(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1915, __PRETTY_FUNCTION__))
1914 StrKind == CaptureStrKind::DisposeHelper) &&(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1915, __PRETTY_FUNCTION__))
1915 "unexpected CaptureStrKind")(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1915, __PRETTY_FUNCTION__))
;
1916 std::string Name = StrKind == CaptureStrKind::CopyHelper
1917 ? "__copy_helper_block_"
1918 : "__destroy_helper_block_";
1919 if (CGM.getLangOpts().Exceptions)
1920 Name += "e";
1921 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1922 Name += "a";
1923 Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1924
1925 for (const BlockCaptureManagedEntity &E : Captures) {
1926 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1927 Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1928 }
1929
1930 return Name;
1931}
1932
1933static void pushCaptureCleanup(BlockCaptureEntityKind CaptureKind,
1934 Address Field, QualType CaptureType,
1935 BlockFieldFlags Flags, bool ForCopyHelper,
1936 VarDecl *Var, CodeGenFunction &CGF) {
1937 bool EHOnly = ForCopyHelper;
1938
1939 switch (CaptureKind) {
1940 case BlockCaptureEntityKind::CXXRecord:
1941 case BlockCaptureEntityKind::ARCWeak:
1942 case BlockCaptureEntityKind::NonTrivialCStruct:
1943 case BlockCaptureEntityKind::ARCStrong: {
1944 if (CaptureType.isDestructedType() &&
1945 (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1946 CodeGenFunction::Destroyer *Destroyer =
1947 CaptureKind == BlockCaptureEntityKind::ARCStrong
1948 ? CodeGenFunction::destroyARCStrongImprecise
1949 : CGF.getDestroyer(CaptureType.isDestructedType());
1950 CleanupKind Kind =
1951 EHOnly ? EHCleanup
1952 : CGF.getCleanupKind(CaptureType.isDestructedType());
1953 CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1954 }
1955 break;
1956 }
1957 case BlockCaptureEntityKind::BlockObject: {
1958 if (!EHOnly || CGF.getLangOpts().Exceptions) {
1959 CleanupKind Kind = EHOnly ? EHCleanup : NormalAndEHCleanup;
1960 // Calls to _Block_object_dispose along the EH path in the copy helper
1961 // function don't throw as newly-copied __block variables always have a
1962 // reference count of 2.
1963 bool CanThrow =
1964 !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1965 CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1966 CanThrow);
1967 }
1968 break;
1969 }
1970 case BlockCaptureEntityKind::None:
1971 break;
1972 }
1973}
1974
1975static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType,
1976 llvm::Function *Fn,
1977 const CGFunctionInfo &FI,
1978 CodeGenModule &CGM) {
1979 if (CapturesNonExternalType) {
1980 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
1981 } else {
1982 Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1983 Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1984 CGM.SetLLVMFunctionAttributes(nullptr, FI, Fn);
1985 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1986 }
1987}
1988/// Generate the copy-helper function for a block closure object:
1989/// static void block_copy_helper(block_t *dst, block_t *src);
1990/// The runtime will have previously initialized 'dst' by doing a
1991/// bit-copy of 'src'.
1992///
1993/// Note that this copies an entire block closure object to the heap;
1994/// it should not be confused with a 'byref copy helper', which moves
1995/// the contents of an individual __block variable to the heap.
1996llvm::Constant *
1997CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
1998 SmallVector<BlockCaptureManagedEntity, 4> CopiedCaptures;
1999 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
2000 std::string FuncName =
2001 getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
2002 CaptureStrKind::CopyHelper, CGM);
2003
2004 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2005 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2006
2007 ASTContext &C = getContext();
2008
2009 FunctionArgList args;
2010 ImplicitParamDecl DstDecl(getContext(), C.VoidPtrTy,
2011 ImplicitParamDecl::Other);
2012 args.push_back(&DstDecl);
2013 ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
2014 ImplicitParamDecl::Other);
2015 args.push_back(&SrcDecl);
2016
2017 const CGFunctionInfo &FI =
2018 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
2019
2020 // FIXME: it would be nice if these were mergeable with things with
2021 // identical semantics.
2022 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2023
2024 llvm::Function *Fn =
2025 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2026 FuncName, &CGM.getModule());
2027
2028 IdentifierInfo *II
2029 = &CGM.getContext().Idents.get(FuncName);
2030
2031 FunctionDecl *FD = FunctionDecl::Create(C,
2032 C.getTranslationUnitDecl(),
2033 SourceLocation(),
2034 SourceLocation(), II, C.VoidTy,
2035 nullptr, SC_Static,
2036 false,
2037 false);
2038
2039 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2040 CGM);
2041 StartFunction(FD, C.VoidTy, Fn, FI, args);
2042 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2043 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2044
2045 Address src = GetAddrOfLocalVar(&SrcDecl);
2046 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2047 src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2048
2049 Address dst = GetAddrOfLocalVar(&DstDecl);
2050 dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2051 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2052
2053 for (const auto &CopiedCapture : CopiedCaptures) {
2054 const BlockDecl::Capture &CI = *CopiedCapture.CI;
2055 const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2056 QualType captureType = CI.getVariable()->getType();
2057 BlockFieldFlags flags = CopiedCapture.CopyFlags;
2058
2059 unsigned index = capture.getIndex();
2060 Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
2061 Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
2062
2063 switch (CopiedCapture.CopyKind) {
2064 case BlockCaptureEntityKind::CXXRecord:
2065 // If there's an explicit copy expression, we do that.
2066 assert(CI.getCopyExpr() && "copy expression for variable is missing")((CI.getCopyExpr() && "copy expression for variable is missing"
) ? static_cast<void> (0) : __assert_fail ("CI.getCopyExpr() && \"copy expression for variable is missing\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2066, __PRETTY_FUNCTION__))
;
2067 EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2068 break;
2069 case BlockCaptureEntityKind::ARCWeak:
2070 EmitARCCopyWeak(dstField, srcField);
2071 break;
2072 case BlockCaptureEntityKind::NonTrivialCStruct: {
2073 // If this is a C struct that requires non-trivial copy construction,
2074 // emit a call to its copy constructor.
2075 QualType varType = CI.getVariable()->getType();
2076 callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2077 MakeAddrLValue(srcField, varType));
2078 break;
2079 }
2080 case BlockCaptureEntityKind::ARCStrong: {
2081 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2082 // At -O0, store null into the destination field (so that the
2083 // storeStrong doesn't over-release) and then call storeStrong.
2084 // This is a workaround to not having an initStrong call.
2085 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2086 auto *ty = cast<llvm::PointerType>(srcValue->getType());
2087 llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2088 Builder.CreateStore(null, dstField);
2089 EmitARCStoreStrongCall(dstField, srcValue, true);
2090
2091 // With optimization enabled, take advantage of the fact that
2092 // the blocks runtime guarantees a memcpy of the block data, and
2093 // just emit a retain of the src field.
2094 } else {
2095 EmitARCRetainNonBlock(srcValue);
2096
2097 // Unless EH cleanup is required, we don't need this anymore, so kill
2098 // it. It's not quite worth the annoyance to avoid creating it in the
2099 // first place.
2100 if (!needsEHCleanup(captureType.isDestructedType()))
2101 cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2102 }
2103 break;
2104 }
2105 case BlockCaptureEntityKind::BlockObject: {
2106 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2107 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2108 llvm::Value *dstAddr =
2109 Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2110 llvm::Value *args[] = {
2111 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2112 };
2113
2114 if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2115 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2116 else
2117 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2118 break;
2119 }
2120 case BlockCaptureEntityKind::None:
2121 continue;
2122 }
2123
2124 // Ensure that we destroy the copied object if an exception is thrown later
2125 // in the helper function.
2126 pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2127 /*ForCopyHelper*/ true, CI.getVariable(), *this);
2128 }
2129
2130 FinishFunction();
2131
2132 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2133}
2134
2135static BlockFieldFlags
2136getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI,
2137 QualType T) {
2138 BlockFieldFlags Flags = BLOCK_FIELD_IS_OBJECT;
2139 if (T->isBlockPointerType())
2140 Flags = BLOCK_FIELD_IS_BLOCK;
2141 return Flags;
2142}
2143
2144static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2145computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
2146 const LangOptions &LangOpts) {
2147 if (CI.isEscapingByref()) {
2148 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2149 if (T.isObjCGCWeak())
2150 Flags |= BLOCK_FIELD_IS_WEAK;
2151 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2152 }
2153
2154 switch (T.isDestructedType()) {
2155 case QualType::DK_cxx_destructor:
2156 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2157 case QualType::DK_objc_strong_lifetime:
2158 // Use objc_storeStrong for __strong direct captures; the
2159 // dynamic tools really like it when we do this.
2160 return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2161 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2162 case QualType::DK_objc_weak_lifetime:
2163 // Support __weak direct captures.
2164 return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2165 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2166 case QualType::DK_nontrivial_c_struct:
2167 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2168 BlockFieldFlags());
2169 case QualType::DK_none: {
2170 // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2171 if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2172 !LangOpts.ObjCAutoRefCount)
2173 return std::make_pair(BlockCaptureEntityKind::BlockObject,
2174 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2175 // Otherwise, we have nothing to do.
2176 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2177 }
2178 }
2179 llvm_unreachable("after exhaustive DestructionKind switch")::llvm::llvm_unreachable_internal("after exhaustive DestructionKind switch"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2179)
;
2180}
2181
2182/// Generate the destroy-helper function for a block closure object:
2183/// static void block_destroy_helper(block_t *theBlock);
2184///
2185/// Note that this destroys a heap-allocated block closure object;
2186/// it should not be confused with a 'byref destroy helper', which
2187/// destroys the heap-allocated contents of an individual __block
2188/// variable.
2189llvm::Constant *
2190CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
2191 SmallVector<BlockCaptureManagedEntity, 4> DestroyedCaptures;
2192 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2193 std::string FuncName =
2194 getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2195 CaptureStrKind::DisposeHelper, CGM);
2196
2197 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2198 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2199
2200 ASTContext &C = getContext();
2201
2202 FunctionArgList args;
2203 ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
2204 ImplicitParamDecl::Other);
2205 args.push_back(&SrcDecl);
2206
2207 const CGFunctionInfo &FI =
2208 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
2209
2210 // FIXME: We'd like to put these into a mergable by content, with
2211 // internal linkage.
2212 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2213
2214 llvm::Function *Fn =
2215 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2216 FuncName, &CGM.getModule());
2217
2218 IdentifierInfo *II
2219 = &CGM.getContext().Idents.get(FuncName);
2220
2221 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(),
2222 SourceLocation(),
2223 SourceLocation(), II, C.VoidTy,
2224 nullptr, SC_Static,
2225 false, false);
2226
2227 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2228 CGM);
2229 StartFunction(FD, C.VoidTy, Fn, FI, args);
2230 markAsIgnoreThreadCheckingAtRuntime(Fn);
2231
2232 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2233
2234 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2235
2236 Address src = GetAddrOfLocalVar(&SrcDecl);
2237 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2238 src = Builder.CreateBitCast(src, structPtrTy, "block");
2239
2240 CodeGenFunction::RunCleanupsScope cleanups(*this);
2241
2242 for (const auto &DestroyedCapture : DestroyedCaptures) {
2243 const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2244 const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2245 BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2246
2247 Address srcField =
2248 Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
2249
2250 pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2251 CI.getVariable()->getType(), flags,
2252 /*ForCopyHelper*/ false, CI.getVariable(), *this);
2253 }
2254
2255 cleanups.ForceCleanup();
2256
2257 FinishFunction();
2258
2259 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2260}
2261
2262namespace {
2263
2264/// Emits the copy/dispose helper functions for a __block object of id type.
2265class ObjectByrefHelpers final : public BlockByrefHelpers {
2266 BlockFieldFlags Flags;
2267
2268public:
2269 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2270 : BlockByrefHelpers(alignment), Flags(flags) {}
2271
2272 void emitCopy(CodeGenFunction &CGF, Address destField,
2273 Address srcField) override {
2274 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2275
2276 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2277 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2278
2279 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2280
2281 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2282 llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
2283
2284 llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2285 CGF.EmitNounwindRuntimeCall(fn, args);
2286 }
2287
2288 void emitDispose(CodeGenFunction &CGF, Address field) override {
2289 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2290 llvm::Value *value = CGF.Builder.CreateLoad(field);
2291
2292 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2293 }
2294
2295 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2296 id.AddInteger(Flags.getBitMask());
2297 }
2298};
2299
2300/// Emits the copy/dispose helpers for an ARC __block __weak variable.
2301class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2302public:
2303 ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2304
2305 void emitCopy(CodeGenFunction &CGF, Address destField,
2306 Address srcField) override {
2307 CGF.EmitARCMoveWeak(destField, srcField);
2308 }
2309
2310 void emitDispose(CodeGenFunction &CGF, Address field) override {
2311 CGF.EmitARCDestroyWeak(field);
2312 }
2313
2314 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2315 // 0 is distinguishable from all pointers and byref flags
2316 id.AddInteger(0);
2317 }
2318};
2319
2320/// Emits the copy/dispose helpers for an ARC __block __strong variable
2321/// that's not of block-pointer type.
2322class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2323public:
2324 ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2325
2326 void emitCopy(CodeGenFunction &CGF, Address destField,
2327 Address srcField) override {
2328 // Do a "move" by copying the value and then zeroing out the old
2329 // variable.
2330
2331 llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2332
2333 llvm::Value *null =
2334 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2335
2336 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2337 CGF.Builder.CreateStore(null, destField);
2338 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2339 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2340 return;
2341 }
2342 CGF.Builder.CreateStore(value, destField);
2343 CGF.Builder.CreateStore(null, srcField);
2344 }
2345
2346 void emitDispose(CodeGenFunction &CGF, Address field) override {
2347 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2348 }
2349
2350 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2351 // 1 is distinguishable from all pointers and byref flags
2352 id.AddInteger(1);
2353 }
2354};
2355
2356/// Emits the copy/dispose helpers for an ARC __block __strong
2357/// variable that's of block-pointer type.
2358class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2359public:
2360 ARCStrongBlockByrefHelpers(CharUnits alignment)
2361 : BlockByrefHelpers(alignment) {}
2362
2363 void emitCopy(CodeGenFunction &CGF, Address destField,
2364 Address srcField) override {
2365 // Do the copy with objc_retainBlock; that's all that
2366 // _Block_object_assign would do anyway, and we'd have to pass the
2367 // right arguments to make sure it doesn't get no-op'ed.
2368 llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2369 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2370 CGF.Builder.CreateStore(copy, destField);
2371 }
2372
2373 void emitDispose(CodeGenFunction &CGF, Address field) override {
2374 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2375 }
2376
2377 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2378 // 2 is distinguishable from all pointers and byref flags
2379 id.AddInteger(2);
2380 }
2381};
2382
2383/// Emits the copy/dispose helpers for a __block variable with a
2384/// nontrivial copy constructor or destructor.
2385class CXXByrefHelpers final : public BlockByrefHelpers {
2386 QualType VarType;
2387 const Expr *CopyExpr;
2388
2389public:
2390 CXXByrefHelpers(CharUnits alignment, QualType type,
2391 const Expr *copyExpr)
2392 : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2393
2394 bool needsCopy() const override { return CopyExpr != nullptr; }
2395 void emitCopy(CodeGenFunction &CGF, Address destField,
2396 Address srcField) override {
2397 if (!CopyExpr) return;
2398 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2399 }
2400
2401 void emitDispose(CodeGenFunction &CGF, Address field) override {
2402 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2403 CGF.PushDestructorCleanup(VarType, field);
2404 CGF.PopCleanupBlocks(cleanupDepth);
2405 }
2406
2407 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2408 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2409 }
2410};
2411
2412/// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2413/// C struct.
2414class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2415 QualType VarType;
2416
2417public:
2418 NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2419 : BlockByrefHelpers(alignment), VarType(type) {}
2420
2421 void emitCopy(CodeGenFunction &CGF, Address destField,
2422 Address srcField) override {
2423 CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2424 CGF.MakeAddrLValue(srcField, VarType));
2425 }
2426
2427 bool needsDispose() const override {
2428 return VarType.isDestructedType();
2429 }
2430
2431 void emitDispose(CodeGenFunction &CGF, Address field) override {
2432 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2433 CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2434 CGF.PopCleanupBlocks(cleanupDepth);
2435 }
2436
2437 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2438 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2439 }
2440};
2441} // end anonymous namespace
2442
2443static llvm::Constant *
2444generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo,
2445 BlockByrefHelpers &generator) {
2446 ASTContext &Context = CGF.getContext();
2447
2448 QualType R = Context.VoidTy;
2449
2450 FunctionArgList args;
2451 ImplicitParamDecl Dst(CGF.getContext(), Context.VoidPtrTy,
2452 ImplicitParamDecl::Other);
2453 args.push_back(&Dst);
2454
2455 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2456 ImplicitParamDecl::Other);
2457 args.push_back(&Src);
2458
2459 const CGFunctionInfo &FI =
2460 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
2461
2462 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2463
2464 // FIXME: We'd like to put these into a mergable by content, with
2465 // internal linkage.
2466 llvm::Function *Fn =
2467 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2468 "__Block_byref_object_copy_", &CGF.CGM.getModule());
2469
2470 IdentifierInfo *II
2471 = &Context.Idents.get("__Block_byref_object_copy_");
2472
2473 FunctionDecl *FD = FunctionDecl::Create(Context,
2474 Context.getTranslationUnitDecl(),
2475 SourceLocation(),
2476 SourceLocation(), II, R, nullptr,
2477 SC_Static,
2478 false, false);
2479
2480 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2481
2482 CGF.StartFunction(FD, R, Fn, FI, args);
2483
2484 if (generator.needsCopy()) {
2485 llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2486
2487 // dst->x
2488 Address destField = CGF.GetAddrOfLocalVar(&Dst);
2489 destField = Address(CGF.Builder.CreateLoad(destField),
2490 byrefInfo.ByrefAlignment);
2491 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2492 destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2493 "dest-object");
2494
2495 // src->x
2496 Address srcField = CGF.GetAddrOfLocalVar(&Src);
2497 srcField = Address(CGF.Builder.CreateLoad(srcField),
2498 byrefInfo.ByrefAlignment);
2499 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2500 srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2501 "src-object");
2502
2503 generator.emitCopy(CGF, destField, srcField);
2504 }
2505
2506 CGF.FinishFunction();
2507
2508 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2509}
2510
2511/// Build the copy helper for a __block variable.
2512static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2513 const BlockByrefInfo &byrefInfo,
2514 BlockByrefHelpers &generator) {
2515 CodeGenFunction CGF(CGM);
2516 return generateByrefCopyHelper(CGF, byrefInfo, generator);
2517}
2518
2519/// Generate code for a __block variable's dispose helper.
2520static llvm::Constant *
2521generateByrefDisposeHelper(CodeGenFunction &CGF,
2522 const BlockByrefInfo &byrefInfo,
2523 BlockByrefHelpers &generator) {
2524 ASTContext &Context = CGF.getContext();
2525 QualType R = Context.VoidTy;
2526
2527 FunctionArgList args;
2528 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2529 ImplicitParamDecl::Other);
2530 args.push_back(&Src);
2531
2532 const CGFunctionInfo &FI =
2533 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
2534
2535 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2536
2537 // FIXME: We'd like to put these into a mergable by content, with
2538 // internal linkage.
2539 llvm::Function *Fn =
2540 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2541 "__Block_byref_object_dispose_",
2542 &CGF.CGM.getModule());
2543
2544 IdentifierInfo *II
2545 = &Context.Idents.get("__Block_byref_object_dispose_");
2546
2547 FunctionDecl *FD = FunctionDecl::Create(Context,
2548 Context.getTranslationUnitDecl(),
2549 SourceLocation(),
2550 SourceLocation(), II, R, nullptr,
2551 SC_Static,
2552 false, false);
2553
2554 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2555
2556 CGF.StartFunction(FD, R, Fn, FI, args);
2557
2558 if (generator.needsDispose()) {
2559 Address addr = CGF.GetAddrOfLocalVar(&Src);
2560 addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2561 auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2562 addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2563 addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2564
2565 generator.emitDispose(CGF, addr);
2566 }
2567
2568 CGF.FinishFunction();
2569
2570 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2571}
2572
2573/// Build the dispose helper for a __block variable.
2574static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2575 const BlockByrefInfo &byrefInfo,
2576 BlockByrefHelpers &generator) {
2577 CodeGenFunction CGF(CGM);
2578 return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2579}
2580
2581/// Lazily build the copy and dispose helpers for a __block variable
2582/// with the given information.
2583template <class T>
2584static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2585 T &&generator) {
2586 llvm::FoldingSetNodeID id;
2587 generator.Profile(id);
2588
2589 void *insertPos;
2590 BlockByrefHelpers *node
2591 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2592 if (node) return static_cast<T*>(node);
2593
2594 generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2595 generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2596
2597 T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2598 CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2599 return copy;
2600}
2601
2602/// Build the copy and dispose helpers for the given __block variable
2603/// emission. Places the helpers in the global cache. Returns null
2604/// if no helpers are required.
2605BlockByrefHelpers *
2606CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2607 const AutoVarEmission &emission) {
2608 const VarDecl &var = *emission.Variable;
2609 assert(var.isEscapingByref() &&((var.isEscapingByref() && "only escaping __block variables need byref helpers"
) ? static_cast<void> (0) : __assert_fail ("var.isEscapingByref() && \"only escaping __block variables need byref helpers\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2610, __PRETTY_FUNCTION__))
2610 "only escaping __block variables need byref helpers")((var.isEscapingByref() && "only escaping __block variables need byref helpers"
) ? static_cast<void> (0) : __assert_fail ("var.isEscapingByref() && \"only escaping __block variables need byref helpers\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2610, __PRETTY_FUNCTION__))
;
2611
2612 QualType type = var.getType();
2613
2614 auto &byrefInfo = getBlockByrefInfo(&var);
2615
2616 // The alignment we care about for the purposes of uniquing byref
2617 // helpers is the alignment of the actual byref value field.
2618 CharUnits valueAlignment =
2619 byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2620
2621 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2622 const Expr *copyExpr =
2623 CGM.getContext().getBlockVarCopyInit(&var).getCopyExpr();
2624 if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2625
2626 return ::buildByrefHelpers(
2627 CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2628 }
2629
2630 // If type is a non-trivial C struct type that is non-trivial to
2631 // destructly move or destroy, build the copy and dispose helpers.
2632 if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2633 type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2634 return ::buildByrefHelpers(
2635 CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2636
2637 // Otherwise, if we don't have a retainable type, there's nothing to do.
2638 // that the runtime does extra copies.
2639 if (!type->isObjCRetainableType()) return nullptr;
2640
2641 Qualifiers qs = type.getQualifiers();
2642
2643 // If we have lifetime, that dominates.
2644 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2645 switch (lifetime) {
2646 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2646)
;
2647
2648 // These are just bits as far as the runtime is concerned.
2649 case Qualifiers::OCL_ExplicitNone:
2650 case Qualifiers::OCL_Autoreleasing:
2651 return nullptr;
2652
2653 // Tell the runtime that this is ARC __weak, called by the
2654 // byref routines.
2655 case Qualifiers::OCL_Weak:
2656 return ::buildByrefHelpers(CGM, byrefInfo,
2657 ARCWeakByrefHelpers(valueAlignment));
2658
2659 // ARC __strong __block variables need to be retained.
2660 case Qualifiers::OCL_Strong:
2661 // Block pointers need to be copied, and there's no direct
2662 // transfer possible.
2663 if (type->isBlockPointerType()) {
2664 return ::buildByrefHelpers(CGM, byrefInfo,
2665 ARCStrongBlockByrefHelpers(valueAlignment));
2666
2667 // Otherwise, we transfer ownership of the retain from the stack
2668 // to the heap.
2669 } else {
2670 return ::buildByrefHelpers(CGM, byrefInfo,
2671 ARCStrongByrefHelpers(valueAlignment));
2672 }
2673 }
2674 llvm_unreachable("fell out of lifetime switch!")::llvm::llvm_unreachable_internal("fell out of lifetime switch!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2674)
;
2675 }
2676
2677 BlockFieldFlags flags;
2678 if (type->isBlockPointerType()) {
2679 flags |= BLOCK_FIELD_IS_BLOCK;
2680 } else if (CGM.getContext().isObjCNSObjectType(type) ||
2681 type->isObjCObjectPointerType()) {
2682 flags |= BLOCK_FIELD_IS_OBJECT;
2683 } else {
2684 return nullptr;
2685 }
2686
2687 if (type.isObjCGCWeak())
2688 flags |= BLOCK_FIELD_IS_WEAK;
2689
2690 return ::buildByrefHelpers(CGM, byrefInfo,
2691 ObjectByrefHelpers(valueAlignment, flags));
2692}
2693
2694Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2695 const VarDecl *var,
2696 bool followForward) {
2697 auto &info = getBlockByrefInfo(var);
2698 return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2699}
2700
2701Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2702 const BlockByrefInfo &info,
2703 bool followForward,
2704 const llvm::Twine &name) {
2705 // Chase the forwarding address if requested.
2706 if (followForward) {
2707 Address forwardingAddr =
2708 Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2709 baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2710 }
2711
2712 return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2713 info.FieldOffset, name);
2714}
2715
2716/// BuildByrefInfo - This routine changes a __block variable declared as T x
2717/// into:
2718///
2719/// struct {
2720/// void *__isa;
2721/// void *__forwarding;
2722/// int32_t __flags;
2723/// int32_t __size;
2724/// void *__copy_helper; // only if needed
2725/// void *__destroy_helper; // only if needed
2726/// void *__byref_variable_layout;// only if needed
2727/// char padding[X]; // only if needed
2728/// T x;
2729/// } x
2730///
2731const BlockByrefInfo &CodeGenFunction::getBlockByrefInfo(const VarDecl *D) {
2732 auto it = BlockByrefInfos.find(D);
2733 if (it != BlockByrefInfos.end())
2734 return it->second;
2735
2736 llvm::StructType *byrefType =
2737 llvm::StructType::create(getLLVMContext(),
2738 "struct.__block_byref_" + D->getNameAsString());
2739
2740 QualType Ty = D->getType();
2741
2742 CharUnits size;
2743 SmallVector<llvm::Type *, 8> types;
2744
2745 // void *__isa;
2746 types.push_back(Int8PtrTy);
2747 size += getPointerSize();
2748
2749 // void *__forwarding;
2750 types.push_back(llvm::PointerType::getUnqual(byrefType));
2751 size += getPointerSize();
2752
2753 // int32_t __flags;
2754 types.push_back(Int32Ty);
2755 size += CharUnits::fromQuantity(4);
2756
2757 // int32_t __size;
2758 types.push_back(Int32Ty);
2759 size += CharUnits::fromQuantity(4);
2760
2761 // Note that this must match *exactly* the logic in buildByrefHelpers.
2762 bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2763 if (hasCopyAndDispose) {
2764 /// void *__copy_helper;
2765 types.push_back(Int8PtrTy);
2766 size += getPointerSize();
2767
2768 /// void *__destroy_helper;
2769 types.push_back(Int8PtrTy);
2770 size += getPointerSize();
2771 }
2772
2773 bool HasByrefExtendedLayout = false;
2774 Qualifiers::ObjCLifetime Lifetime;
2775 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2776 HasByrefExtendedLayout) {
2777 /// void *__byref_variable_layout;
2778 types.push_back(Int8PtrTy);
2779 size += CharUnits::fromQuantity(PointerSizeInBytes);
2780 }
2781
2782 // T x;
2783 llvm::Type *varTy = ConvertTypeForMem(Ty);
2784
2785 bool packed = false;
2786 CharUnits varAlign = getContext().getDeclAlign(D);
2787 CharUnits varOffset = size.alignTo(varAlign);
2788
2789 // We may have to insert padding.
2790 if (varOffset != size) {
2791 llvm::Type *paddingTy =
2792 llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2793
2794 types.push_back(paddingTy);
2795 size = varOffset;
2796
2797 // Conversely, we might have to prevent LLVM from inserting padding.
2798 } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2799 > varAlign.getQuantity()) {
2800 packed = true;
2801 }
2802 types.push_back(varTy);
2803
2804 byrefType->setBody(types, packed);
2805
2806 BlockByrefInfo info;
2807 info.Type = byrefType;
2808 info.FieldIndex = types.size() - 1;
2809 info.FieldOffset = varOffset;
2810 info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2811
2812 auto pair = BlockByrefInfos.insert({D, info});
2813 assert(pair.second && "info was inserted recursively?")((pair.second && "info was inserted recursively?") ? static_cast
<void> (0) : __assert_fail ("pair.second && \"info was inserted recursively?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2813, __PRETTY_FUNCTION__))
;
2814 return pair.first->second;
2815}
2816
2817/// Initialize the structural components of a __block variable, i.e.
2818/// everything but the actual object.
2819void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) {
2820 // Find the address of the local.
2821 Address addr = emission.Addr;
2822
2823 // That's an alloca of the byref structure type.
2824 llvm::StructType *byrefType = cast<llvm::StructType>(
2825 cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2826
2827 unsigned nextHeaderIndex = 0;
2828 CharUnits nextHeaderOffset;
2829 auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2830 const Twine &name) {
2831 auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2832 nextHeaderOffset, name);
2833 Builder.CreateStore(value, fieldAddr);
2834
2835 nextHeaderIndex++;
2836 nextHeaderOffset += fieldSize;
2837 };
2838
2839 // Build the byref helpers if necessary. This is null if we don't need any.
2840 BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2841
2842 const VarDecl &D = *emission.Variable;
2843 QualType type = D.getType();
2844
2845 bool HasByrefExtendedLayout;
2846 Qualifiers::ObjCLifetime ByrefLifetime;
2847 bool ByRefHasLifetime =
2848 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2849
2850 llvm::Value *V;
2851
2852 // Initialize the 'isa', which is just 0 or 1.
2853 int isa = 0;
2854 if (type.isObjCGCWeak())
2855 isa = 1;
2856 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2857 storeHeaderField(V, getPointerSize(), "byref.isa");
2858
2859 // Store the address of the variable into its own forwarding pointer.
2860 storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2861
2862 // Blocks ABI:
2863 // c) the flags field is set to either 0 if no helper functions are
2864 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2865 BlockFlags flags;
2866 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2867 if (ByRefHasLifetime) {
2868 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2869 else switch (ByrefLifetime) {
2870 case Qualifiers::OCL_Strong:
2871 flags |= BLOCK_BYREF_LAYOUT_STRONG;
2872 break;
2873 case Qualifiers::OCL_Weak:
2874 flags |= BLOCK_BYREF_LAYOUT_WEAK;
2875 break;
2876 case Qualifiers::OCL_ExplicitNone:
2877 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED;
2878 break;
2879 case Qualifiers::OCL_None:
2880 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2881 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT;
2882 break;
2883 default:
2884 break;
2885 }
2886 if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2887 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2888 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2889 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2890 if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2891 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2892 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2893 printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2894 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2895 printf(" BLOCK_BYREF_LAYOUT_STRONG");
2896 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2897 printf(" BLOCK_BYREF_LAYOUT_WEAK");
2898 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2899 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2900 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2901 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2902 }
2903 printf("\n");
2904 }
2905 }
2906 storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2907 getIntSize(), "byref.flags");
2908
2909 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2910 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2911 storeHeaderField(V, getIntSize(), "byref.size");
2912
2913 if (helpers) {
2914 storeHeaderField(helpers->CopyHelper, getPointerSize(),
2915 "byref.copyHelper");
2916 storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2917 "byref.disposeHelper");
2918 }
2919
2920 if (ByRefHasLifetime && HasByrefExtendedLayout) {
2921 auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2922 storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2923 }
2924}
2925
2926void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags,
2927 bool CanThrow) {
2928 llvm::Value *F = CGM.getBlockObjectDispose();
2929 llvm::Value *args[] = {
2930 Builder.CreateBitCast(V, Int8PtrTy),
2931 llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2932 };
2933
2934 if (CanThrow)
2935 EmitRuntimeCallOrInvoke(F, args);
2936 else
2937 EmitNounwindRuntimeCall(F, args);
2938}
2939
2940void CodeGenFunction::enterByrefCleanup(CleanupKind Kind, Address Addr,
2941 BlockFieldFlags Flags,
2942 bool LoadBlockVarAddr, bool CanThrow) {
2943 EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2944 CanThrow);
2945}
2946
2947/// Adjust the declaration of something from the blocks API.
2948static void configureBlocksRuntimeObject(CodeGenModule &CGM,
2949 llvm::Constant *C) {
2950 auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2951
2952 if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2953 IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2954 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2955 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2956
2957 assert((isa<llvm::Function>(C->stripPointerCasts()) ||(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2959, __PRETTY_FUNCTION__))
2958 isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2959, __PRETTY_FUNCTION__))
2959 "expected Function or GlobalVariable")(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2959, __PRETTY_FUNCTION__))
;
2960
2961 const NamedDecl *ND = nullptr;
2962 for (const auto &Result : DC->lookup(&II))
2963 if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2964 (ND = dyn_cast<VarDecl>(Result)))
2965 break;
2966
2967 // TODO: support static blocks runtime
2968 if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2969 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2970 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2971 } else {
2972 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2973 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2974 }
2975 }
2976
2977 if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2978 GV->hasExternalLinkage())
2979 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2980
2981 CGM.setDSOLocal(GV);
2982}
2983
2984llvm::Constant *CodeGenModule::getBlockObjectDispose() {
2985 if (BlockObjectDispose)
2986 return BlockObjectDispose;
2987
2988 llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2989 llvm::FunctionType *fty
2990 = llvm::FunctionType::get(VoidTy, args, false);
2991 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2992 configureBlocksRuntimeObject(*this, BlockObjectDispose);
2993 return BlockObjectDispose;
2994}
2995
2996llvm::Constant *CodeGenModule::getBlockObjectAssign() {
2997 if (BlockObjectAssign)
2998 return BlockObjectAssign;
2999
3000 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
3001 llvm::FunctionType *fty
3002 = llvm::FunctionType::get(VoidTy, args, false);
3003 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3004 configureBlocksRuntimeObject(*this, BlockObjectAssign);
3005 return BlockObjectAssign;
3006}
3007
3008llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
3009 if (NSConcreteGlobalBlock)
3010 return NSConcreteGlobalBlock;
3011
3012 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3013 Int8PtrTy->getPointerTo(),
3014 nullptr);
3015 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3016 return NSConcreteGlobalBlock;
3017}
3018
3019llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
3020 if (NSConcreteStackBlock)
3021 return NSConcreteStackBlock;
3022
3023 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3024 Int8PtrTy->getPointerTo(),
3025 nullptr);
3026 configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3027 return NSConcreteStackBlock;
3028}