Bug Summary

File:tools/clang/lib/CodeGen/CGBlocks.cpp
Warning:line 1805, column 14
Called C++ object pointer is null

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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-10~svn373517/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn373517/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/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/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++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~svn373517/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn373517=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-10-02-234743-9763-1 -x c++ /build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp
1//===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit blocks.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGBlocks.h"
14#include "CGCXXABI.h"
15#include "CGDebugInfo.h"
16#include "CGObjCRuntime.h"
17#include "CGOpenCLRuntime.h"
18#include "CodeGenFunction.h"
19#include "CodeGenModule.h"
20#include "ConstantEmitter.h"
21#include "TargetInfo.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/CodeGen/ConstantInitBuilder.h"
24#include "llvm/ADT/SmallSet.h"
25#include "llvm/IR/DataLayout.h"
26#include "llvm/IR/Module.h"
27#include "llvm/Support/ScopedPrinter.h"
28#include <algorithm>
29#include <cstdio>
30
31using namespace clang;
32using namespace CodeGen;
33
34CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
35 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
36 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
37 CapturesNonExternalType(false), LocalAddress(Address::invalid()),
38 StructureType(nullptr), Block(block), DominatingIP(nullptr) {
39
40 // Skip asm prefix, if any. 'name' is usually taken directly from
41 // the mangled name of the enclosing function.
42 if (!name.empty() && name[0] == '\01')
43 name = name.substr(1);
44}
45
46// Anchor the vtable to this translation unit.
47BlockByrefHelpers::~BlockByrefHelpers() {}
48
49/// Build the given block as a global block.
50static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
51 const CGBlockInfo &blockInfo,
52 llvm::Constant *blockFn);
53
54/// Build the helper function to copy a block.
55static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
56 const CGBlockInfo &blockInfo) {
57 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
58}
59
60/// Build the helper function to dispose of a block.
61static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
62 const CGBlockInfo &blockInfo) {
63 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
64}
65
66namespace {
67
68/// Represents a type of copy/destroy operation that should be performed for an
69/// entity that's captured by a block.
70enum class BlockCaptureEntityKind {
71 CXXRecord, // Copy or destroy
72 ARCWeak,
73 ARCStrong,
74 NonTrivialCStruct,
75 BlockObject, // Assign or release
76 None
77};
78
79/// Represents a captured entity that requires extra operations in order for
80/// this entity to be copied or destroyed correctly.
81struct BlockCaptureManagedEntity {
82 BlockCaptureEntityKind CopyKind, DisposeKind;
83 BlockFieldFlags CopyFlags, DisposeFlags;
84 const BlockDecl::Capture *CI;
85 const CGBlockInfo::Capture *Capture;
86
87 BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
88 BlockCaptureEntityKind DisposeType,
89 BlockFieldFlags CopyFlags,
90 BlockFieldFlags DisposeFlags,
91 const BlockDecl::Capture &CI,
92 const CGBlockInfo::Capture &Capture)
93 : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
94 DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
95
96 bool operator<(const BlockCaptureManagedEntity &Other) const {
97 return Capture->getOffset() < Other.Capture->getOffset();
98 }
99};
100
101enum class CaptureStrKind {
102 // String for the copy helper.
103 CopyHelper,
104 // String for the dispose helper.
105 DisposeHelper,
106 // Merge the strings for the copy helper and dispose helper.
107 Merged
108};
109
110} // end anonymous namespace
111
112static void findBlockCapturedManagedEntities(
113 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
114 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
115
116static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
117 CaptureStrKind StrKind,
118 CharUnits BlockAlignment,
119 CodeGenModule &CGM);
120
121static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
122 CodeGenModule &CGM) {
123 std::string Name = "__block_descriptor_";
124 Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
125
126 if (BlockInfo.needsCopyDisposeHelpers()) {
127 if (CGM.getLangOpts().Exceptions)
128 Name += "e";
129 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
130 Name += "a";
131 Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
132
133 SmallVector<BlockCaptureManagedEntity, 4> ManagedCaptures;
134 findBlockCapturedManagedEntities(BlockInfo, CGM.getContext().getLangOpts(),
135 ManagedCaptures);
136
137 for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
138 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
139
140 if (E.CopyKind == E.DisposeKind) {
141 // If CopyKind and DisposeKind are the same, merge the capture
142 // information.
143 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 144, __PRETTY_FUNCTION__))
144 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 144, __PRETTY_FUNCTION__))
;
145 Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
146 BlockInfo.BlockAlign, CGM);
147 } else {
148 // If CopyKind and DisposeKind are not the same, which can happen when
149 // either Kind is None or the captured object is a __strong block,
150 // concatenate the copy and dispose strings.
151 Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
152 BlockInfo.BlockAlign, CGM);
153 Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
154 BlockInfo.BlockAlign, CGM);
155 }
156 }
157 Name += "_";
158 }
159
160 std::string TypeAtEncoding =
161 CGM.getContext().getObjCEncodingForBlock(BlockInfo.getBlockExpr());
162 /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
163 /// a separator between symbol name and symbol version.
164 std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
165 Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
166 Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
167 return Name;
168}
169
170/// buildBlockDescriptor - Build the block descriptor meta-data for a block.
171/// buildBlockDescriptor is accessed from 5th field of the Block_literal
172/// meta-data and contains stationary information about the block literal.
173/// Its definition will have 4 (or optionally 6) words.
174/// \code
175/// struct Block_descriptor {
176/// unsigned long reserved;
177/// unsigned long size; // size of Block_literal metadata in bytes.
178/// void *copy_func_helper_decl; // optional copy helper.
179/// void *destroy_func_decl; // optional destructor helper.
180/// void *block_method_encoding_address; // @encode for block literal signature.
181/// void *block_layout_info; // encoding of captured block variables.
182/// };
183/// \endcode
184static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
185 const CGBlockInfo &blockInfo) {
186 ASTContext &C = CGM.getContext();
187
188 llvm::IntegerType *ulong =
189 cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
190 llvm::PointerType *i8p = nullptr;
191 if (CGM.getLangOpts().OpenCL)
192 i8p =
193 llvm::Type::getInt8PtrTy(
194 CGM.getLLVMContext(), C.getTargetAddressSpace(LangAS::opencl_constant));
195 else
196 i8p = CGM.VoidPtrTy;
197
198 std::string descName;
199
200 // If an equivalent block descriptor global variable exists, return it.
201 if (C.getLangOpts().ObjC &&
202 CGM.getLangOpts().getGC() == LangOptions::NonGC) {
203 descName = getBlockDescriptorName(blockInfo, CGM);
204 if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
205 return llvm::ConstantExpr::getBitCast(desc,
206 CGM.getBlockDescriptorType());
207 }
208
209 // If there isn't an equivalent block descriptor global variable, create a new
210 // one.
211 ConstantInitBuilder builder(CGM);
212 auto elements = builder.beginStruct();
213
214 // reserved
215 elements.addInt(ulong, 0);
216
217 // Size
218 // FIXME: What is the right way to say this doesn't fit? We should give
219 // a user diagnostic in that case. Better fix would be to change the
220 // API to size_t.
221 elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
222
223 // Optional copy/dispose helpers.
224 bool hasInternalHelper = false;
225 if (blockInfo.needsCopyDisposeHelpers()) {
226 // copy_func_helper_decl
227 llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
228 elements.add(copyHelper);
229
230 // destroy_func_decl
231 llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
232 elements.add(disposeHelper);
233
234 if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
235 cast<llvm::Function>(disposeHelper->getOperand(0))
236 ->hasInternalLinkage())
237 hasInternalHelper = true;
238 }
239
240 // Signature. Mandatory ObjC-style method descriptor @encode sequence.
241 std::string typeAtEncoding =
242 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr());
243 elements.add(llvm::ConstantExpr::getBitCast(
244 CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
245
246 // GC layout.
247 if (C.getLangOpts().ObjC) {
248 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
249 elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
250 else
251 elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
252 }
253 else
254 elements.addNullPointer(i8p);
255
256 unsigned AddrSpace = 0;
257 if (C.getLangOpts().OpenCL)
258 AddrSpace = C.getTargetAddressSpace(LangAS::opencl_constant);
259
260 llvm::GlobalValue::LinkageTypes linkage;
261 if (descName.empty()) {
262 linkage = llvm::GlobalValue::InternalLinkage;
263 descName = "__block_descriptor_tmp";
264 } else if (hasInternalHelper) {
265 // If either the copy helper or the dispose helper has internal linkage,
266 // the block descriptor must have internal linkage too.
267 linkage = llvm::GlobalValue::InternalLinkage;
268 } else {
269 linkage = llvm::GlobalValue::LinkOnceODRLinkage;
270 }
271
272 llvm::GlobalVariable *global =
273 elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
274 /*constant*/ true, linkage, AddrSpace);
275
276 if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
277 if (CGM.supportsCOMDAT())
278 global->setComdat(CGM.getModule().getOrInsertComdat(descName));
279 global->setVisibility(llvm::GlobalValue::HiddenVisibility);
280 global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
281 }
282
283 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
284}
285
286/*
287 Purely notional variadic template describing the layout of a block.
288
289 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
290 struct Block_literal {
291 /// Initialized to one of:
292 /// extern void *_NSConcreteStackBlock[];
293 /// extern void *_NSConcreteGlobalBlock[];
294 ///
295 /// In theory, we could start one off malloc'ed by setting
296 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
297 /// this isa:
298 /// extern void *_NSConcreteMallocBlock[];
299 struct objc_class *isa;
300
301 /// These are the flags (with corresponding bit number) that the
302 /// compiler is actually supposed to know about.
303 /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
304 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
305 /// descriptor provides copy and dispose helper functions
306 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
307 /// object with a nontrivial destructor or copy constructor
308 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
309 /// as global memory
310 /// 29. BLOCK_USE_STRET - indicates that the block function
311 /// uses stret, which objc_msgSend needs to know about
312 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
313 /// @encoded signature string
314 /// And we're not supposed to manipulate these:
315 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
316 /// to malloc'ed memory
317 /// 27. BLOCK_IS_GC - indicates that the block has been moved to
318 /// to GC-allocated memory
319 /// Additionally, the bottom 16 bits are a reference count which
320 /// should be zero on the stack.
321 int flags;
322
323 /// Reserved; should be zero-initialized.
324 int reserved;
325
326 /// Function pointer generated from block literal.
327 _ResultType (*invoke)(Block_literal *, _ParamTypes...);
328
329 /// Block description metadata generated from block literal.
330 struct Block_descriptor *block_descriptor;
331
332 /// Captured values follow.
333 _CapturesTypes captures...;
334 };
335 */
336
337namespace {
338 /// A chunk of data that we actually have to capture in the block.
339 struct BlockLayoutChunk {
340 CharUnits Alignment;
341 CharUnits Size;
342 Qualifiers::ObjCLifetime Lifetime;
343 const BlockDecl::Capture *Capture; // null for 'this'
344 llvm::Type *Type;
345 QualType FieldType;
346
347 BlockLayoutChunk(CharUnits align, CharUnits size,
348 Qualifiers::ObjCLifetime lifetime,
349 const BlockDecl::Capture *capture,
350 llvm::Type *type, QualType fieldType)
351 : Alignment(align), Size(size), Lifetime(lifetime),
352 Capture(capture), Type(type), FieldType(fieldType) {}
353
354 /// Tell the block info that this chunk has the given field index.
355 void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
356 if (!Capture) {
357 info.CXXThisIndex = index;
358 info.CXXThisOffset = offset;
359 } else {
360 auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
361 info.Captures.insert({Capture->getVariable(), C});
362 }
363 }
364 };
365
366 /// Order by 1) all __strong together 2) next, all byfref together 3) next,
367 /// all __weak together. Preserve descending alignment in all situations.
368 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
369 if (left.Alignment != right.Alignment)
370 return left.Alignment > right.Alignment;
371
372 auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
373 if (chunk.Capture && chunk.Capture->isByRef())
374 return 1;
375 if (chunk.Lifetime == Qualifiers::OCL_Strong)
376 return 0;
377 if (chunk.Lifetime == Qualifiers::OCL_Weak)
378 return 2;
379 return 3;
380 };
381
382 return getPrefOrder(left) < getPrefOrder(right);
383 }
384} // end anonymous namespace
385
386/// Determines if the given type is safe for constant capture in C++.
387static bool isSafeForCXXConstantCapture(QualType type) {
388 const RecordType *recordType =
389 type->getBaseElementTypeUnsafe()->getAs<RecordType>();
390
391 // Only records can be unsafe.
392 if (!recordType) return true;
393
394 const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
395
396 // Maintain semantics for classes with non-trivial dtors or copy ctors.
397 if (!record->hasTrivialDestructor()) return false;
398 if (record->hasNonTrivialCopyConstructor()) return false;
399
400 // Otherwise, we just have to make sure there aren't any mutable
401 // fields that might have changed since initialization.
402 return !record->hasMutableFields();
403}
404
405/// It is illegal to modify a const object after initialization.
406/// Therefore, if a const object has a constant initializer, we don't
407/// actually need to keep storage for it in the block; we'll just
408/// rematerialize it at the start of the block function. This is
409/// acceptable because we make no promises about address stability of
410/// captured variables.
411static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
412 CodeGenFunction *CGF,
413 const VarDecl *var) {
414 // Return if this is a function parameter. We shouldn't try to
415 // rematerialize default arguments of function parameters.
416 if (isa<ParmVarDecl>(var))
417 return nullptr;
418
419 QualType type = var->getType();
420
421 // We can only do this if the variable is const.
422 if (!type.isConstQualified()) return nullptr;
423
424 // Furthermore, in C++ we have to worry about mutable fields:
425 // C++ [dcl.type.cv]p4:
426 // Except that any class member declared mutable can be
427 // modified, any attempt to modify a const object during its
428 // lifetime results in undefined behavior.
429 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
430 return nullptr;
431
432 // If the variable doesn't have any initializer (shouldn't this be
433 // invalid?), it's not clear what we should do. Maybe capture as
434 // zero?
435 const Expr *init = var->getInit();
436 if (!init) return nullptr;
437
438 return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
439}
440
441/// Get the low bit of a nonzero character count. This is the
442/// alignment of the nth byte if the 0th byte is universally aligned.
443static CharUnits getLowBit(CharUnits v) {
444 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
445}
446
447static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
448 SmallVectorImpl<llvm::Type*> &elementTypes) {
449
450 assert(elementTypes.empty())((elementTypes.empty()) ? static_cast<void> (0) : __assert_fail
("elementTypes.empty()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 450, __PRETTY_FUNCTION__))
;
451 if (CGM.getLangOpts().OpenCL) {
452 // The header is basically 'struct { int; int; generic void *;
453 // custom_fields; }'. Assert that struct is packed.
454 auto GenericAS =
455 CGM.getContext().getTargetAddressSpace(LangAS::opencl_generic);
456 auto GenPtrAlign =
457 CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
458 auto GenPtrSize =
459 CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
460 assert(CGM.getIntSize() <= GenPtrSize)((CGM.getIntSize() <= GenPtrSize) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntSize() <= GenPtrSize", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 460, __PRETTY_FUNCTION__))
;
461 assert(CGM.getIntAlign() <= GenPtrAlign)((CGM.getIntAlign() <= GenPtrAlign) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntAlign() <= GenPtrAlign", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 461, __PRETTY_FUNCTION__))
;
462 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 462, __PRETTY_FUNCTION__))
;
463 elementTypes.push_back(CGM.IntTy); /* total size */
464 elementTypes.push_back(CGM.IntTy); /* align */
465 elementTypes.push_back(
466 CGM.getOpenCLRuntime()
467 .getGenericVoidPointerType()); /* invoke function */
468 unsigned Offset =
469 2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
470 unsigned BlockAlign = GenPtrAlign.getQuantity();
471 if (auto *Helper =
472 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
473 for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
474 // TargetOpenCLBlockHelp needs to make sure the struct is packed.
475 // If necessary, add padding fields to the custom fields.
476 unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
477 if (BlockAlign < Align)
478 BlockAlign = Align;
479 assert(Offset % Align == 0)((Offset % Align == 0) ? static_cast<void> (0) : __assert_fail
("Offset % Align == 0", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 479, __PRETTY_FUNCTION__))
;
480 Offset += CGM.getDataLayout().getTypeAllocSize(I);
481 elementTypes.push_back(I);
482 }
483 }
484 info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
485 info.BlockSize = CharUnits::fromQuantity(Offset);
486 } else {
487 // The header is basically 'struct { void *; int; int; void *; void *; }'.
488 // Assert that the struct is packed.
489 assert(CGM.getIntSize() <= CGM.getPointerSize())((CGM.getIntSize() <= CGM.getPointerSize()) ? static_cast<
void> (0) : __assert_fail ("CGM.getIntSize() <= CGM.getPointerSize()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 489, __PRETTY_FUNCTION__))
;
490 assert(CGM.getIntAlign() <= CGM.getPointerAlign())((CGM.getIntAlign() <= CGM.getPointerAlign()) ? static_cast
<void> (0) : __assert_fail ("CGM.getIntAlign() <= CGM.getPointerAlign()"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 490, __PRETTY_FUNCTION__))
;
491 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 491, __PRETTY_FUNCTION__))
;
492 info.BlockAlign = CGM.getPointerAlign();
493 info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
494 elementTypes.push_back(CGM.VoidPtrTy);
495 elementTypes.push_back(CGM.IntTy);
496 elementTypes.push_back(CGM.IntTy);
497 elementTypes.push_back(CGM.VoidPtrTy);
498 elementTypes.push_back(CGM.getBlockDescriptorType());
499 }
500}
501
502static QualType getCaptureFieldType(const CodeGenFunction &CGF,
503 const BlockDecl::Capture &CI) {
504 const VarDecl *VD = CI.getVariable();
505
506 // If the variable is captured by an enclosing block or lambda expression,
507 // use the type of the capture field.
508 if (CGF.BlockInfo && CI.isNested())
509 return CGF.BlockInfo->getCapture(VD).fieldType();
510 if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
511 return FD->getType();
512 // If the captured variable is a non-escaping __block variable, the field
513 // type is the reference type. If the variable is a __block variable that
514 // already has a reference type, the field type is the variable's type.
515 return VD->isNonEscapingByref() ?
516 CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
517}
518
519/// Compute the layout of the given block. Attempts to lay the block
520/// out with minimal space requirements.
521static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF,
522 CGBlockInfo &info) {
523 ASTContext &C = CGM.getContext();
524 const BlockDecl *block = info.getBlockDecl();
525
526 SmallVector<llvm::Type*, 8> elementTypes;
527 initializeForBlockHeader(CGM, info, elementTypes);
528 bool hasNonConstantCustomFields = false;
529 if (auto *OpenCLHelper =
530 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper())
531 hasNonConstantCustomFields =
532 !OpenCLHelper->areAllCustomFieldValuesConstant(info);
533 if (!block->hasCaptures() && !hasNonConstantCustomFields) {
534 info.StructureType =
535 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
536 info.CanBeGlobal = true;
537 return;
538 }
539 else if (C.getLangOpts().ObjC &&
540 CGM.getLangOpts().getGC() == LangOptions::NonGC)
541 info.HasCapturedVariableLayout = true;
542
543 // Collect the layout chunks.
544 SmallVector<BlockLayoutChunk, 16> layout;
545 layout.reserve(block->capturesCXXThis() +
546 (block->capture_end() - block->capture_begin()));
547
548 CharUnits maxFieldAlign;
549
550 // First, 'this'.
551 if (block->capturesCXXThis()) {
552 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 553, __PRETTY_FUNCTION__))
553 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 553, __PRETTY_FUNCTION__))
;
554 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType();
555
556 // Theoretically, this could be in a different address space, so
557 // don't assume standard pointer size/align.
558 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
559 std::pair<CharUnits,CharUnits> tinfo
560 = CGM.getContext().getTypeInfoInChars(thisType);
561 maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
562
563 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
564 Qualifiers::OCL_None,
565 nullptr, llvmType, thisType));
566 }
567
568 // Next, all the block captures.
569 for (const auto &CI : block->captures()) {
570 const VarDecl *variable = CI.getVariable();
571
572 if (CI.isEscapingByref()) {
573 // We have to copy/dispose of the __block reference.
574 info.NeedsCopyDispose = true;
575
576 // Just use void* instead of a pointer to the byref type.
577 CharUnits align = CGM.getPointerAlign();
578 maxFieldAlign = std::max(maxFieldAlign, align);
579
580 // Since a __block variable cannot be captured by lambdas, its type and
581 // the capture field type should always match.
582 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 583, __PRETTY_FUNCTION__))
583 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 583, __PRETTY_FUNCTION__))
;
584 layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
585 Qualifiers::OCL_None, &CI,
586 CGM.VoidPtrTy, variable->getType()));
587 continue;
588 }
589
590 // Otherwise, build a layout chunk with the size and alignment of
591 // the declaration.
592 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
593 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
594 continue;
595 }
596
597 QualType VT = getCaptureFieldType(*CGF, CI);
598
599 // If we have a lifetime qualifier, honor it for capture purposes.
600 // That includes *not* copying it if it's __unsafe_unretained.
601 Qualifiers::ObjCLifetime lifetime = VT.getObjCLifetime();
602 if (lifetime) {
603 switch (lifetime) {
604 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 604)
;
605 case Qualifiers::OCL_ExplicitNone:
606 case Qualifiers::OCL_Autoreleasing:
607 break;
608
609 case Qualifiers::OCL_Strong:
610 case Qualifiers::OCL_Weak:
611 info.NeedsCopyDispose = true;
612 }
613
614 // Block pointers require copy/dispose. So do Objective-C pointers.
615 } else if (VT->isObjCRetainableType()) {
616 // But honor the inert __unsafe_unretained qualifier, which doesn't
617 // actually make it into the type system.
618 if (VT->isObjCInertUnsafeUnretainedType()) {
619 lifetime = Qualifiers::OCL_ExplicitNone;
620 } else {
621 info.NeedsCopyDispose = true;
622 // used for mrr below.
623 lifetime = Qualifiers::OCL_Strong;
624 }
625
626 // So do types that require non-trivial copy construction.
627 } else if (CI.hasCopyExpr()) {
628 info.NeedsCopyDispose = true;
629 info.HasCXXObject = true;
630 if (!VT->getAsCXXRecordDecl()->isExternallyVisible())
631 info.CapturesNonExternalType = true;
632
633 // So do C structs that require non-trivial copy construction or
634 // destruction.
635 } else if (VT.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct ||
636 VT.isDestructedType() == QualType::DK_nontrivial_c_struct) {
637 info.NeedsCopyDispose = true;
638
639 // And so do types with destructors.
640 } else if (CGM.getLangOpts().CPlusPlus) {
641 if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
642 if (!record->hasTrivialDestructor()) {
643 info.HasCXXObject = true;
644 info.NeedsCopyDispose = true;
645 if (!record->isExternallyVisible())
646 info.CapturesNonExternalType = true;
647 }
648 }
649 }
650
651 CharUnits size = C.getTypeSizeInChars(VT);
652 CharUnits align = C.getDeclAlign(variable);
653
654 maxFieldAlign = std::max(maxFieldAlign, align);
655
656 llvm::Type *llvmType =
657 CGM.getTypes().ConvertTypeForMem(VT);
658
659 layout.push_back(
660 BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
661 }
662
663 // If that was everything, we're done here.
664 if (layout.empty()) {
665 info.StructureType =
666 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
667 info.CanBeGlobal = true;
668 return;
669 }
670
671 // Sort the layout by alignment. We have to use a stable sort here
672 // to get reproducible results. There should probably be an
673 // llvm::array_pod_stable_sort.
674 llvm::stable_sort(layout);
675
676 // Needed for blocks layout info.
677 info.BlockHeaderForcedGapOffset = info.BlockSize;
678 info.BlockHeaderForcedGapSize = CharUnits::Zero();
679
680 CharUnits &blockSize = info.BlockSize;
681 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
682
683 // Assuming that the first byte in the header is maximally aligned,
684 // get the alignment of the first byte following the header.
685 CharUnits endAlign = getLowBit(blockSize);
686
687 // If the end of the header isn't satisfactorily aligned for the
688 // maximum thing, look for things that are okay with the header-end
689 // alignment, and keep appending them until we get something that's
690 // aligned right. This algorithm is only guaranteed optimal if
691 // that condition is satisfied at some point; otherwise we can get
692 // things like:
693 // header // next byte has alignment 4
694 // something_with_size_5; // next byte has alignment 1
695 // something_with_alignment_8;
696 // which has 7 bytes of padding, as opposed to the naive solution
697 // which might have less (?).
698 if (endAlign < maxFieldAlign) {
699 SmallVectorImpl<BlockLayoutChunk>::iterator
700 li = layout.begin() + 1, le = layout.end();
701
702 // Look for something that the header end is already
703 // satisfactorily aligned for.
704 for (; li != le && endAlign < li->Alignment; ++li)
705 ;
706
707 // If we found something that's naturally aligned for the end of
708 // the header, keep adding things...
709 if (li != le) {
710 SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
711 for (; li != le; ++li) {
712 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 712, __PRETTY_FUNCTION__))
;
713
714 li->setIndex(info, elementTypes.size(), blockSize);
715 elementTypes.push_back(li->Type);
716 blockSize += li->Size;
717 endAlign = getLowBit(blockSize);
718
719 // ...until we get to the alignment of the maximum field.
720 if (endAlign >= maxFieldAlign) {
721 break;
722 }
723 }
724 // Don't re-append everything we just appended.
725 layout.erase(first, li);
726 }
727 }
728
729 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 729, __PRETTY_FUNCTION__))
;
730
731 // At this point, we just have to add padding if the end align still
732 // isn't aligned right.
733 if (endAlign < maxFieldAlign) {
734 CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
735 CharUnits padding = newBlockSize - blockSize;
736
737 // If we haven't yet added any fields, remember that there was an
738 // initial gap; this need to go into the block layout bit map.
739 if (blockSize == info.BlockHeaderForcedGapOffset) {
740 info.BlockHeaderForcedGapSize = padding;
741 }
742
743 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
744 padding.getQuantity()));
745 blockSize = newBlockSize;
746 endAlign = getLowBit(blockSize); // might be > maxFieldAlign
747 }
748
749 assert(endAlign >= maxFieldAlign)((endAlign >= maxFieldAlign) ? static_cast<void> (0)
: __assert_fail ("endAlign >= maxFieldAlign", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 749, __PRETTY_FUNCTION__))
;
750 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 750, __PRETTY_FUNCTION__))
;
751 // Slam everything else on now. This works because they have
752 // strictly decreasing alignment and we expect that size is always a
753 // multiple of alignment.
754 for (SmallVectorImpl<BlockLayoutChunk>::iterator
755 li = layout.begin(), le = layout.end(); li != le; ++li) {
756 if (endAlign < li->Alignment) {
757 // size may not be multiple of alignment. This can only happen with
758 // an over-aligned variable. We will be adding a padding field to
759 // make the size be multiple of alignment.
760 CharUnits padding = li->Alignment - endAlign;
761 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
762 padding.getQuantity()));
763 blockSize += padding;
764 endAlign = getLowBit(blockSize);
765 }
766 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 766, __PRETTY_FUNCTION__))
;
767 li->setIndex(info, elementTypes.size(), blockSize);
768 elementTypes.push_back(li->Type);
769 blockSize += li->Size;
770 endAlign = getLowBit(blockSize);
771 }
772
773 info.StructureType =
774 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
775}
776
777/// Enter the scope of a block. This should be run at the entrance to
778/// a full-expression so that the block's cleanups are pushed at the
779/// right place in the stack.
780static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
781 assert(CGF.HaveInsertPoint())((CGF.HaveInsertPoint()) ? static_cast<void> (0) : __assert_fail
("CGF.HaveInsertPoint()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 781, __PRETTY_FUNCTION__))
;
782
783 // Allocate the block info and place it at the head of the list.
784 CGBlockInfo &blockInfo =
785 *new CGBlockInfo(block, CGF.CurFn->getName());
786 blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
787 CGF.FirstBlockInfo = &blockInfo;
788
789 // Compute information about the layout, etc., of this block,
790 // pushing cleanups as necessary.
791 computeBlockInfo(CGF.CGM, &CGF, blockInfo);
792
793 // Nothing else to do if it can be global.
794 if (blockInfo.CanBeGlobal) return;
795
796 // Make the allocation for the block.
797 blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
798 blockInfo.BlockAlign, "block");
799
800 // If there are cleanups to emit, enter them (but inactive).
801 if (!blockInfo.NeedsCopyDispose) return;
802
803 // Walk through the captures (in order) and find the ones not
804 // captured by constant.
805 for (const auto &CI : block->captures()) {
806 // Ignore __block captures; there's nothing special in the
807 // on-stack block that we need to do for them.
808 if (CI.isByRef()) continue;
809
810 // Ignore variables that are constant-captured.
811 const VarDecl *variable = CI.getVariable();
812 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
813 if (capture.isConstant()) continue;
814
815 // Ignore objects that aren't destructed.
816 QualType VT = getCaptureFieldType(CGF, CI);
817 QualType::DestructionKind dtorKind = VT.isDestructedType();
818 if (dtorKind == QualType::DK_none) continue;
819
820 CodeGenFunction::Destroyer *destroyer;
821
822 // Block captures count as local values and have imprecise semantics.
823 // They also can't be arrays, so need to worry about that.
824 //
825 // For const-qualified captures, emit clang.arc.use to ensure the captured
826 // object doesn't get released while we are still depending on its validity
827 // within the block.
828 if (VT.isConstQualified() &&
829 VT.getObjCLifetime() == Qualifiers::OCL_Strong &&
830 CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
831 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 832, __PRETTY_FUNCTION__))
832 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 832, __PRETTY_FUNCTION__))
;
833 destroyer = CodeGenFunction::emitARCIntrinsicUse;
834 } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
835 destroyer = CodeGenFunction::destroyARCStrongImprecise;
836 } else {
837 destroyer = CGF.getDestroyer(dtorKind);
838 }
839
840 // GEP down to the address.
841 Address addr =
842 CGF.Builder.CreateStructGEP(blockInfo.LocalAddress, capture.getIndex());
843
844 // We can use that GEP as the dominating IP.
845 if (!blockInfo.DominatingIP)
846 blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
847
848 CleanupKind cleanupKind = InactiveNormalCleanup;
849 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
850 if (useArrayEHCleanup)
851 cleanupKind = InactiveNormalAndEHCleanup;
852
853 CGF.pushDestroy(cleanupKind, addr, VT,
854 destroyer, useArrayEHCleanup);
855
856 // Remember where that cleanup was.
857 capture.setCleanup(CGF.EHStack.stable_begin());
858 }
859}
860
861/// Enter a full-expression with a non-trivial number of objects to
862/// clean up. This is in this file because, at the moment, the only
863/// kind of cleanup object is a BlockDecl*.
864void CodeGenFunction::enterNonTrivialFullExpression(const FullExpr *E) {
865 if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
866 assert(EWC->getNumObjects() != 0)((EWC->getNumObjects() != 0) ? static_cast<void> (0)
: __assert_fail ("EWC->getNumObjects() != 0", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 866, __PRETTY_FUNCTION__))
;
867 for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
868 enterBlockScope(*this, C);
869 }
870}
871
872/// Find the layout for the given block in a linked list and remove it.
873static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head,
874 const BlockDecl *block) {
875 while (true) {
876 assert(head && *head)((head && *head) ? static_cast<void> (0) : __assert_fail
("head && *head", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 876, __PRETTY_FUNCTION__))
;
877 CGBlockInfo *cur = *head;
878
879 // If this is the block we're looking for, splice it out of the list.
880 if (cur->getBlockDecl() == block) {
881 *head = cur->NextBlockInfo;
882 return cur;
883 }
884
885 head = &cur->NextBlockInfo;
886 }
887}
888
889/// Destroy a chain of block layouts.
890void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) {
891 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 891, __PRETTY_FUNCTION__))
;
892 do {
893 CGBlockInfo *cur = head;
894 head = cur->NextBlockInfo;
895 delete cur;
896 } while (head != nullptr);
897}
898
899/// Emit a block literal expression in the current function.
900llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
901 // If the block has no captures, we won't have a pre-computed
902 // layout for it.
903 if (!blockExpr->getBlockDecl()->hasCaptures()) {
904 // The block literal is emitted as a global variable, and the block invoke
905 // function has to be extracted from its initializer.
906 if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
907 return Block;
908 }
909 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
910 computeBlockInfo(CGM, this, blockInfo);
911 blockInfo.BlockExpression = blockExpr;
912 return EmitBlockLiteral(blockInfo);
913 }
914
915 // Find the block info for this block and take ownership of it.
916 std::unique_ptr<CGBlockInfo> blockInfo;
917 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
918 blockExpr->getBlockDecl()));
919
920 blockInfo->BlockExpression = blockExpr;
921 return EmitBlockLiteral(*blockInfo);
922}
923
924llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
925 bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
926 auto GenVoidPtrTy =
927 IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
928 LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
929 auto GenVoidPtrSize = CharUnits::fromQuantity(
930 CGM.getTarget().getPointerWidth(
931 CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
932 8);
933 // Using the computed layout, generate the actual block function.
934 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
935 CodeGenFunction BlockCGF{CGM, true};
936 BlockCGF.SanOpts = SanOpts;
937 auto *InvokeFn = BlockCGF.GenerateBlockFunction(
938 CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
939 auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
940
941 // If there is nothing to capture, we can emit this as a global block.
942 if (blockInfo.CanBeGlobal)
943 return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
944
945 // Otherwise, we have to emit this as a local block.
946
947 Address blockAddr = blockInfo.LocalAddress;
948 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 948, __PRETTY_FUNCTION__))
;
949
950 llvm::Constant *isa;
951 llvm::Constant *descriptor;
952 BlockFlags flags;
953 if (!IsOpenCL) {
954 // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
955 // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
956 // block just returns the original block and releasing it is a no-op.
957 llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
958 ? CGM.getNSConcreteGlobalBlock()
959 : CGM.getNSConcreteStackBlock();
960 isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
961
962 // Build the block descriptor.
963 descriptor = buildBlockDescriptor(CGM, blockInfo);
964
965 // Compute the initial on-stack block flags.
966 flags = BLOCK_HAS_SIGNATURE;
967 if (blockInfo.HasCapturedVariableLayout)
968 flags |= BLOCK_HAS_EXTENDED_LAYOUT;
969 if (blockInfo.needsCopyDisposeHelpers())
970 flags |= BLOCK_HAS_COPY_DISPOSE;
971 if (blockInfo.HasCXXObject)
972 flags |= BLOCK_HAS_CXX_OBJ;
973 if (blockInfo.UsesStret)
974 flags |= BLOCK_USE_STRET;
975 if (blockInfo.getBlockDecl()->doesNotEscape())
976 flags |= BLOCK_IS_NOESCAPE | BLOCK_IS_GLOBAL;
977 }
978
979 auto projectField = [&](unsigned index, const Twine &name) -> Address {
980 return Builder.CreateStructGEP(blockAddr, index, name);
981 };
982 auto storeField = [&](llvm::Value *value, unsigned index, const Twine &name) {
983 Builder.CreateStore(value, projectField(index, name));
984 };
985
986 // Initialize the block header.
987 {
988 // We assume all the header fields are densely packed.
989 unsigned index = 0;
990 CharUnits offset;
991 auto addHeaderField = [&](llvm::Value *value, CharUnits size,
992 const Twine &name) {
993 storeField(value, index, name);
994 offset += size;
995 index++;
996 };
997
998 if (!IsOpenCL) {
999 addHeaderField(isa, getPointerSize(), "block.isa");
1000 addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1001 getIntSize(), "block.flags");
1002 addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1003 "block.reserved");
1004 } else {
1005 addHeaderField(
1006 llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1007 getIntSize(), "block.size");
1008 addHeaderField(
1009 llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1010 getIntSize(), "block.align");
1011 }
1012 addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1013 if (!IsOpenCL)
1014 addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1015 else if (auto *Helper =
1016 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1017 for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1018 addHeaderField(
1019 I.first,
1020 CharUnits::fromQuantity(
1021 CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1022 I.second);
1023 }
1024 }
1025 }
1026
1027 // Finally, capture all the values into the block.
1028 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1029
1030 // First, 'this'.
1031 if (blockDecl->capturesCXXThis()) {
1032 Address addr =
1033 projectField(blockInfo.CXXThisIndex, "block.captured-this.addr");
1034 Builder.CreateStore(LoadCXXThis(), addr);
1035 }
1036
1037 // Next, captured variables.
1038 for (const auto &CI : blockDecl->captures()) {
1039 const VarDecl *variable = CI.getVariable();
1040 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1041
1042 // Ignore constant captures.
1043 if (capture.isConstant()) continue;
1044
1045 QualType type = capture.fieldType();
1046
1047 // This will be a [[type]]*, except that a byref entry will just be
1048 // an i8**.
1049 Address blockField = projectField(capture.getIndex(), "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 "block.capture.addr");
1069 } else {
1070 auto I = LocalDeclMap.find(variable);
1071 assert(I != LocalDeclMap.end())((I != LocalDeclMap.end()) ? static_cast<void> (0) : __assert_fail
("I != LocalDeclMap.end()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1071, __PRETTY_FUNCTION__))
;
1072 src = I->second;
1073 }
1074 } else {
1075 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1076 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1077 type.getNonReferenceType(), VK_LValue,
1078 SourceLocation());
1079 src = EmitDeclRefLValue(&declRef).getAddress();
1080 };
1081
1082 // For byrefs, we just write the pointer to the byref struct into
1083 // the block field. There's no need to chase the forwarding
1084 // pointer at this point, since we're building something that will
1085 // live a shorter life than the stack byref anyway.
1086 if (CI.isEscapingByref()) {
1087 // Get a void* that points to the byref struct.
1088 llvm::Value *byrefPointer;
1089 if (CI.isNested())
1090 byrefPointer = Builder.CreateLoad(src, "byref.capture");
1091 else
1092 byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1093
1094 // Write that void* into the capture field.
1095 Builder.CreateStore(byrefPointer, blockField);
1096
1097 // If we have a copy constructor, evaluate that into the block field.
1098 } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1099 if (blockDecl->isConversionFromLambda()) {
1100 // If we have a lambda conversion, emit the expression
1101 // directly into the block instead.
1102 AggValueSlot Slot =
1103 AggValueSlot::forAddr(blockField, Qualifiers(),
1104 AggValueSlot::IsDestructed,
1105 AggValueSlot::DoesNotNeedGCBarriers,
1106 AggValueSlot::IsNotAliased,
1107 AggValueSlot::DoesNotOverlap);
1108 EmitAggExpr(copyExpr, Slot);
1109 } else {
1110 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1111 }
1112
1113 // If it's a reference variable, copy the reference into the block field.
1114 } else if (type->isReferenceType()) {
1115 Builder.CreateStore(src.getPointer(), blockField);
1116
1117 // If type is const-qualified, copy the value into the block field.
1118 } else if (type.isConstQualified() &&
1119 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1120 CGM.getCodeGenOpts().OptimizationLevel != 0) {
1121 llvm::Value *value = Builder.CreateLoad(src, "captured");
1122 Builder.CreateStore(value, blockField);
1123
1124 // If this is an ARC __strong block-pointer variable, don't do a
1125 // block copy.
1126 //
1127 // TODO: this can be generalized into the normal initialization logic:
1128 // we should never need to do a block-copy when initializing a local
1129 // variable, because the local variable's lifetime should be strictly
1130 // contained within the stack block's.
1131 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1132 type->isBlockPointerType()) {
1133 // Load the block and do a simple retain.
1134 llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1135 value = EmitARCRetainNonBlock(value);
1136
1137 // Do a primitive store to the block field.
1138 Builder.CreateStore(value, blockField);
1139
1140 // Otherwise, fake up a POD copy into the block field.
1141 } else {
1142 // Fake up a new variable so that EmitScalarInit doesn't think
1143 // we're referring to the variable in its own initializer.
1144 ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1145 ImplicitParamDecl::Other);
1146
1147 // We use one of these or the other depending on whether the
1148 // reference is nested.
1149 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1150 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1151 type, VK_LValue, SourceLocation());
1152
1153 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1154 &declRef, VK_RValue);
1155 // FIXME: Pass a specific location for the expr init so that the store is
1156 // attributed to a reasonable location - otherwise it may be attributed to
1157 // locations of subexpressions in the initialization.
1158 EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1159 MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1160 /*captured by init*/ false);
1161 }
1162
1163 // Activate the cleanup if layout pushed one.
1164 if (!CI.isByRef()) {
1165 EHScopeStack::stable_iterator cleanup = capture.getCleanup();
1166 if (cleanup.isValid())
1167 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1168 }
1169 }
1170
1171 // Cast to the converted block-pointer type, which happens (somewhat
1172 // unfortunately) to be a pointer to function type.
1173 llvm::Value *result = Builder.CreatePointerCast(
1174 blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1175
1176 if (IsOpenCL) {
1177 CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1178 result);
1179 }
1180
1181 return result;
1182}
1183
1184
1185llvm::Type *CodeGenModule::getBlockDescriptorType() {
1186 if (BlockDescriptorType)
1187 return BlockDescriptorType;
1188
1189 llvm::Type *UnsignedLongTy =
1190 getTypes().ConvertType(getContext().UnsignedLongTy);
1191
1192 // struct __block_descriptor {
1193 // unsigned long reserved;
1194 // unsigned long block_size;
1195 //
1196 // // later, the following will be added
1197 //
1198 // struct {
1199 // void (*copyHelper)();
1200 // void (*copyHelper)();
1201 // } helpers; // !!! optional
1202 //
1203 // const char *signature; // the block signature
1204 // const char *layout; // reserved
1205 // };
1206 BlockDescriptorType = llvm::StructType::create(
1207 "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1208
1209 // Now form a pointer to that.
1210 unsigned AddrSpace = 0;
1211 if (getLangOpts().OpenCL)
1212 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1213 BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1214 return BlockDescriptorType;
1215}
1216
1217llvm::Type *CodeGenModule::getGenericBlockLiteralType() {
1218 if (GenericBlockLiteralType)
1219 return GenericBlockLiteralType;
1220
1221 llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1222
1223 if (getLangOpts().OpenCL) {
1224 // struct __opencl_block_literal_generic {
1225 // int __size;
1226 // int __align;
1227 // __generic void *__invoke;
1228 // /* custom fields */
1229 // };
1230 SmallVector<llvm::Type *, 8> StructFields(
1231 {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1232 if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1233 for (auto I : Helper->getCustomFieldTypes())
1234 StructFields.push_back(I);
1235 }
1236 GenericBlockLiteralType = llvm::StructType::create(
1237 StructFields, "struct.__opencl_block_literal_generic");
1238 } else {
1239 // struct __block_literal_generic {
1240 // void *__isa;
1241 // int __flags;
1242 // int __reserved;
1243 // void (*__invoke)(void *);
1244 // struct __block_descriptor *__descriptor;
1245 // };
1246 GenericBlockLiteralType =
1247 llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1248 IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1249 }
1250
1251 return GenericBlockLiteralType;
1252}
1253
1254RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E,
1255 ReturnValueSlot ReturnValue) {
1256 const BlockPointerType *BPT =
1257 E->getCallee()->getType()->getAs<BlockPointerType>();
1258 llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1259 llvm::Type *GenBlockTy = CGM.getGenericBlockLiteralType();
1260 llvm::Value *Func = nullptr;
1261 QualType FnType = BPT->getPointeeType();
1262 ASTContext &Ctx = getContext();
1263 CallArgList Args;
1264
1265 if (getLangOpts().OpenCL) {
1266 // For OpenCL, BlockPtr is already casted to generic block literal.
1267
1268 // First argument of a block call is a generic block literal casted to
1269 // generic void pointer, i.e. i8 addrspace(4)*
1270 llvm::Value *BlockDescriptor = Builder.CreatePointerCast(
1271 BlockPtr, CGM.getOpenCLRuntime().getGenericVoidPointerType());
1272 QualType VoidPtrQualTy = Ctx.getPointerType(
1273 Ctx.getAddrSpaceQualType(Ctx.VoidTy, LangAS::opencl_generic));
1274 Args.add(RValue::get(BlockDescriptor), VoidPtrQualTy);
1275 // And the rest of the arguments.
1276 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1277
1278 // We *can* call the block directly unless it is a function argument.
1279 if (!isa<ParmVarDecl>(E->getCalleeDecl()))
1280 Func = CGM.getOpenCLRuntime().getInvokeFunction(E->getCallee());
1281 else {
1282 llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 2);
1283 Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1284 }
1285 } else {
1286 // Bitcast the block literal to a generic block literal.
1287 BlockPtr = Builder.CreatePointerCast(
1288 BlockPtr, llvm::PointerType::get(GenBlockTy, 0), "block.literal");
1289 // Get pointer to the block invoke function
1290 llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 3);
1291
1292 // First argument is a block literal casted to a void pointer
1293 BlockPtr = Builder.CreatePointerCast(BlockPtr, VoidPtrTy);
1294 Args.add(RValue::get(BlockPtr), Ctx.VoidPtrTy);
1295 // And the rest of the arguments.
1296 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1297
1298 // Load the function.
1299 Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1300 }
1301
1302 const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1303 const CGFunctionInfo &FnInfo =
1304 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1305
1306 // Cast the function pointer to the right type.
1307 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1308
1309 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1310 Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1311
1312 // Prepare the callee.
1313 CGCallee Callee(CGCalleeInfo(), Func);
1314
1315 // And call the block.
1316 return EmitCall(FnInfo, Callee, ReturnValue, Args);
1317}
1318
1319Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable) {
1320 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1320, __PRETTY_FUNCTION__))
;
1321 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1322
1323 // Handle constant captures.
1324 if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1325
1326 Address addr = Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1327 "block.capture.addr");
1328
1329 if (variable->isEscapingByref()) {
1330 // addr should be a void** right now. Load, then cast the result
1331 // to byref*.
1332
1333 auto &byrefInfo = getBlockByrefInfo(variable);
1334 addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1335
1336 auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1337 addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1338
1339 addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1340 variable->getName());
1341 }
1342
1343 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1346, __PRETTY_FUNCTION__))
1344 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1346, __PRETTY_FUNCTION__))
1345 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1346, __PRETTY_FUNCTION__))
1346 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1346, __PRETTY_FUNCTION__))
;
1347 if (capture.fieldType()->isReferenceType())
1348 addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1349
1350 return addr;
1351}
1352
1353void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
1354 llvm::Constant *Addr) {
1355 bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1356 (void)Ok;
1357 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1357, __PRETTY_FUNCTION__))
;
1358}
1359
1360llvm::Constant *
1361CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
1362 StringRef Name) {
1363 if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1364 return Block;
1365
1366 CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1367 blockInfo.BlockExpression = BE;
1368
1369 // Compute information about the layout, etc., of this block.
1370 computeBlockInfo(*this, nullptr, blockInfo);
1371
1372 // Using that metadata, generate the actual block function.
1373 {
1374 CodeGenFunction::DeclMapTy LocalDeclMap;
1375 CodeGenFunction(*this).GenerateBlockFunction(
1376 GlobalDecl(), blockInfo, LocalDeclMap,
1377 /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1378 }
1379
1380 return getAddrOfGlobalBlockIfEmitted(BE);
1381}
1382
1383static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1384 const CGBlockInfo &blockInfo,
1385 llvm::Constant *blockFn) {
1386 assert(blockInfo.CanBeGlobal)((blockInfo.CanBeGlobal) ? static_cast<void> (0) : __assert_fail
("blockInfo.CanBeGlobal", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1386, __PRETTY_FUNCTION__))
;
1387 // Callers should detect this case on their own: calling this function
1388 // generally requires computing layout information, which is a waste of time
1389 // if we've already emitted this block.
1390 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1391, __PRETTY_FUNCTION__))
1391 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1391, __PRETTY_FUNCTION__))
;
1392
1393 // Generate the constants for the block literal initializer.
1394 ConstantInitBuilder builder(CGM);
1395 auto fields = builder.beginStruct();
1396
1397 bool IsOpenCL = CGM.getLangOpts().OpenCL;
1398 bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1399 if (!IsOpenCL) {
1400 // isa
1401 if (IsWindows)
1402 fields.addNullPointer(CGM.Int8PtrPtrTy);
1403 else
1404 fields.add(CGM.getNSConcreteGlobalBlock());
1405
1406 // __flags
1407 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE;
1408 if (blockInfo.UsesStret)
1409 flags |= BLOCK_USE_STRET;
1410
1411 fields.addInt(CGM.IntTy, flags.getBitMask());
1412
1413 // Reserved
1414 fields.addInt(CGM.IntTy, 0);
1415 } else {
1416 fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1417 fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1418 }
1419
1420 // Function
1421 fields.add(blockFn);
1422
1423 if (!IsOpenCL) {
1424 // Descriptor
1425 fields.add(buildBlockDescriptor(CGM, blockInfo));
1426 } else if (auto *Helper =
1427 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1428 for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1429 fields.add(I);
1430 }
1431 }
1432
1433 unsigned AddrSpace = 0;
1434 if (CGM.getContext().getLangOpts().OpenCL)
1435 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
1436
1437 llvm::GlobalVariable *literal = fields.finishAndCreateGlobal(
1438 "__block_literal_global", blockInfo.BlockAlign,
1439 /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1440
1441 literal->addAttribute("objc_arc_inert");
1442
1443 // Windows does not allow globals to be initialised to point to globals in
1444 // different DLLs. Any such variables must run code to initialise them.
1445 if (IsWindows) {
1446 auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1447 {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1448 &CGM.getModule());
1449 llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1450 Init));
1451 b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1452 b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1453 b.CreateRetVoid();
1454 // We can't use the normal LLVM global initialisation array, because we
1455 // need to specify that this runs early in library initialisation.
1456 auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1457 /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1458 Init, ".block_isa_init_ptr");
1459 InitVar->setSection(".CRT$XCLa");
1460 CGM.addUsedGlobal(InitVar);
1461 }
1462
1463 // Return a constant of the appropriately-casted type.
1464 llvm::Type *RequiredType =
1465 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1466 llvm::Constant *Result =
1467 llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1468 CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1469 if (CGM.getContext().getLangOpts().OpenCL)
1470 CGM.getOpenCLRuntime().recordBlockInfo(
1471 blockInfo.BlockExpression,
1472 cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1473 return Result;
1474}
1475
1476void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,
1477 unsigned argNum,
1478 llvm::Value *arg) {
1479 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1479, __PRETTY_FUNCTION__))
;
1480
1481 // Allocate a stack slot like for any local variable to guarantee optimal
1482 // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1483 Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1484 Builder.CreateStore(arg, alloc);
1485 if (CGDebugInfo *DI = getDebugInfo()) {
1486 if (CGM.getCodeGenOpts().getDebugInfo() >=
1487 codegenoptions::LimitedDebugInfo) {
1488 DI->setLocation(D->getLocation());
1489 DI->EmitDeclareOfBlockLiteralArgVariable(
1490 *BlockInfo, D->getName(), argNum,
1491 cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1492 }
1493 }
1494
1495 SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1496 ApplyDebugLocation Scope(*this, StartLoc);
1497
1498 // Instead of messing around with LocalDeclMap, just set the value
1499 // directly as BlockPointer.
1500 BlockPointer = Builder.CreatePointerCast(
1501 arg,
1502 BlockInfo->StructureType->getPointerTo(
1503 getContext().getLangOpts().OpenCL
1504 ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1505 : 0),
1506 "block");
1507}
1508
1509Address CodeGenFunction::LoadBlockStruct() {
1510 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1510, __PRETTY_FUNCTION__))
;
1511 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1511, __PRETTY_FUNCTION__))
;
1512 return Address(BlockPointer, BlockInfo->BlockAlign);
1513}
1514
1515llvm::Function *
1516CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
1517 const CGBlockInfo &blockInfo,
1518 const DeclMapTy &ldm,
1519 bool IsLambdaConversionToBlock,
1520 bool BuildGlobalBlock) {
1521 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1522
1523 CurGD = GD;
1524
1525 CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1526
1527 BlockInfo = &blockInfo;
1528
1529 // Arrange for local static and local extern declarations to appear
1530 // to be local to this function as well, in case they're directly
1531 // referenced in a block.
1532 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1533 const auto *var = dyn_cast<VarDecl>(i->first);
1534 if (var && !var->hasLocalStorage())
1535 setAddrOfLocalVar(var, i->second);
1536 }
1537
1538 // Begin building the function declaration.
1539
1540 // Build the argument list.
1541 FunctionArgList args;
1542
1543 // The first argument is the block pointer. Just take it as a void*
1544 // and cast it later.
1545 QualType selfTy = getContext().VoidPtrTy;
1546
1547 // For OpenCL passed block pointer can be private AS local variable or
1548 // global AS program scope variable (for the case with and without captures).
1549 // Generic AS is used therefore to be able to accommodate both private and
1550 // generic AS in one implementation.
1551 if (getLangOpts().OpenCL)
1552 selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1553 getContext().VoidTy, LangAS::opencl_generic));
1554
1555 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1556
1557 ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1558 SourceLocation(), II, selfTy,
1559 ImplicitParamDecl::ObjCSelf);
1560 args.push_back(&SelfDecl);
1561
1562 // Now add the rest of the parameters.
1563 args.append(blockDecl->param_begin(), blockDecl->param_end());
1564
1565 // Create the function declaration.
1566 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1567 const CGFunctionInfo &fnInfo =
1568 CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1569 if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1570 blockInfo.UsesStret = true;
1571
1572 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1573
1574 StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1575 llvm::Function *fn = llvm::Function::Create(
1576 fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1577 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1578
1579 if (BuildGlobalBlock) {
1580 auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1581 ? CGM.getOpenCLRuntime().getGenericVoidPointerType()
1582 : VoidPtrTy;
1583 buildGlobalBlock(CGM, blockInfo,
1584 llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1585 }
1586
1587 // Begin generating the function.
1588 StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1589 blockDecl->getLocation(),
1590 blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1591
1592 // Okay. Undo some of what StartFunction did.
1593
1594 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1595 // won't delete the dbg.declare intrinsics for captured variables.
1596 llvm::Value *BlockPointerDbgLoc = BlockPointer;
1597 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1598 // Allocate a stack slot for it, so we can point the debugger to it
1599 Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1600 getPointerAlign(),
1601 "block.addr");
1602 // Set the DebugLocation to empty, so the store is recognized as a
1603 // frame setup instruction by llvm::DwarfDebug::beginFunction().
1604 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1605 Builder.CreateStore(BlockPointer, Alloca);
1606 BlockPointerDbgLoc = Alloca.getPointer();
1607 }
1608
1609 // If we have a C++ 'this' reference, go ahead and force it into
1610 // existence now.
1611 if (blockDecl->capturesCXXThis()) {
1612 Address addr = Builder.CreateStructGEP(
1613 LoadBlockStruct(), blockInfo.CXXThisIndex, "block.captured-this");
1614 CXXThisValue = Builder.CreateLoad(addr, "this");
1615 }
1616
1617 // Also force all the constant captures.
1618 for (const auto &CI : blockDecl->captures()) {
1619 const VarDecl *variable = CI.getVariable();
1620 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1621 if (!capture.isConstant()) continue;
1622
1623 CharUnits align = getContext().getDeclAlign(variable);
1624 Address alloca =
1625 CreateMemTemp(variable->getType(), align, "block.captured-const");
1626
1627 Builder.CreateStore(capture.getConstant(), alloca);
1628
1629 setAddrOfLocalVar(variable, alloca);
1630 }
1631
1632 // Save a spot to insert the debug information for all the DeclRefExprs.
1633 llvm::BasicBlock *entry = Builder.GetInsertBlock();
1634 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1635 --entry_ptr;
1636
1637 if (IsLambdaConversionToBlock)
1638 EmitLambdaBlockInvokeBody();
1639 else {
1640 PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1641 incrementProfileCounter(blockDecl->getBody());
1642 EmitStmt(blockDecl->getBody());
1643 }
1644
1645 // Remember where we were...
1646 llvm::BasicBlock *resume = Builder.GetInsertBlock();
1647
1648 // Go back to the entry.
1649 ++entry_ptr;
1650 Builder.SetInsertPoint(entry, entry_ptr);
1651
1652 // Emit debug information for all the DeclRefExprs.
1653 // FIXME: also for 'this'
1654 if (CGDebugInfo *DI = getDebugInfo()) {
1655 for (const auto &CI : blockDecl->captures()) {
1656 const VarDecl *variable = CI.getVariable();
1657 DI->EmitLocation(Builder, variable->getLocation());
1658
1659 if (CGM.getCodeGenOpts().getDebugInfo() >=
1660 codegenoptions::LimitedDebugInfo) {
1661 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1662 if (capture.isConstant()) {
1663 auto addr = LocalDeclMap.find(variable)->second;
1664 (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1665 Builder);
1666 continue;
1667 }
1668
1669 DI->EmitDeclareOfBlockDeclRefVariable(
1670 variable, BlockPointerDbgLoc, Builder, blockInfo,
1671 entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1672 }
1673 }
1674 // Recover location if it was changed in the above loop.
1675 DI->EmitLocation(Builder,
1676 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1677 }
1678
1679 // And resume where we left off.
1680 if (resume == nullptr)
1681 Builder.ClearInsertionPoint();
1682 else
1683 Builder.SetInsertPoint(resume);
1684
1685 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1686
1687 return fn;
1688}
1689
1690static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1691computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1692 const LangOptions &LangOpts) {
1693 if (CI.getCopyExpr()) {
1694 assert(!CI.isByRef())((!CI.isByRef()) ? static_cast<void> (0) : __assert_fail
("!CI.isByRef()", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1694, __PRETTY_FUNCTION__))
;
1695 // don't bother computing flags
1696 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1697 }
1698 BlockFieldFlags Flags;
1699 if (CI.isEscapingByref()) {
1700 Flags = BLOCK_FIELD_IS_BYREF;
1701 if (T.isObjCGCWeak())
1702 Flags |= BLOCK_FIELD_IS_WEAK;
1703 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1704 }
1705
1706 Flags = BLOCK_FIELD_IS_OBJECT;
1707 bool isBlockPointer = T->isBlockPointerType();
1708 if (isBlockPointer)
1709 Flags = BLOCK_FIELD_IS_BLOCK;
1710
1711 switch (T.isNonTrivialToPrimitiveCopy()) {
1712 case QualType::PCK_Struct:
1713 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1714 BlockFieldFlags());
1715 case QualType::PCK_ARCWeak:
1716 // We need to register __weak direct captures with the runtime.
1717 return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1718 case QualType::PCK_ARCStrong:
1719 // We need to retain the copied value for __strong direct captures.
1720 // If it's a block pointer, we have to copy the block and assign that to
1721 // the destination pointer, so we might as well use _Block_object_assign.
1722 // Otherwise we can avoid that.
1723 return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1724 : BlockCaptureEntityKind::BlockObject,
1725 Flags);
1726 case QualType::PCK_Trivial:
1727 case QualType::PCK_VolatileTrivial: {
1728 if (!T->isObjCRetainableType())
1729 // For all other types, the memcpy is fine.
1730 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1731
1732 // Special rules for ARC captures:
1733 Qualifiers QS = T.getQualifiers();
1734
1735 // Non-ARC captures of retainable pointers are strong and
1736 // therefore require a call to _Block_object_assign.
1737 if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1738 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1739
1740 // Otherwise the memcpy is fine.
1741 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1742 }
1743 }
1744 llvm_unreachable("after exhaustive PrimitiveCopyKind switch")::llvm::llvm_unreachable_internal("after exhaustive PrimitiveCopyKind switch"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1744)
;
1745}
1746
1747static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1748computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1749 const LangOptions &LangOpts);
1750
1751/// Find the set of block captures that need to be explicitly copied or destroy.
1752static void findBlockCapturedManagedEntities(
1753 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1754 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1755 for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1756 const VarDecl *Variable = CI.getVariable();
1757 const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1758 if (Capture.isConstant())
1759 continue;
1760
1761 QualType VT = Capture.fieldType();
1762 auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1763 auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1764 if (CopyInfo.first != BlockCaptureEntityKind::None ||
1765 DisposeInfo.first != BlockCaptureEntityKind::None)
1766 ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1767 CopyInfo.second, DisposeInfo.second, CI,
1768 Capture);
1769 }
1770
1771 // Sort the captures by offset.
1772 llvm::sort(ManagedCaptures);
1773}
1774
1775namespace {
1776/// Release a __block variable.
1777struct CallBlockRelease final : EHScopeStack::Cleanup {
1778 Address Addr;
1779 BlockFieldFlags FieldFlags;
1780 bool LoadBlockVarAddr, CanThrow;
1781
1782 CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1783 bool CT)
1784 : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1785 CanThrow(CT) {}
1786
1787 void Emit(CodeGenFunction &CGF, Flags flags) override {
1788 llvm::Value *BlockVarAddr;
1789 if (LoadBlockVarAddr) {
1790 BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1791 BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1792 } else {
1793 BlockVarAddr = Addr.getPointer();
1794 }
1795
1796 CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1797 }
1798};
1799} // end anonymous namespace
1800
1801/// Check if \p T is a C++ class that has a destructor that can throw.
1802bool CodeGenFunction::cxxDestructorCanThrow(QualType T) {
1803 if (const auto *RD = T->getAsCXXRecordDecl())
1
Assuming 'RD' is non-null
2
Taking true branch
1804 if (const CXXDestructorDecl *DD = RD->getDestructor())
3
Assuming 'DD' is non-null
4
Taking true branch
1805 return DD->getType()->getAs<FunctionProtoType>()->canThrow();
5
Assuming the object is not a 'FunctionProtoType'
6
Called C++ object pointer is null
1806 return false;
1807}
1808
1809// Return a string that has the information about a capture.
1810static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1811 CaptureStrKind StrKind,
1812 CharUnits BlockAlignment,
1813 CodeGenModule &CGM) {
1814 std::string Str;
1815 ASTContext &Ctx = CGM.getContext();
1816 const BlockDecl::Capture &CI = *E.CI;
1817 QualType CaptureTy = CI.getVariable()->getType();
1818
1819 BlockCaptureEntityKind Kind;
1820 BlockFieldFlags Flags;
1821
1822 // CaptureStrKind::Merged should be passed only when the operations and the
1823 // flags are the same for copy and dispose.
1824 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1826, __PRETTY_FUNCTION__))
1825 (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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1826, __PRETTY_FUNCTION__))
1826 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1826, __PRETTY_FUNCTION__))
;
1827
1828 if (StrKind == CaptureStrKind::DisposeHelper) {
1829 Kind = E.DisposeKind;
1830 Flags = E.DisposeFlags;
1831 } else {
1832 Kind = E.CopyKind;
1833 Flags = E.CopyFlags;
1834 }
1835
1836 switch (Kind) {
1837 case BlockCaptureEntityKind::CXXRecord: {
1838 Str += "c";
1839 SmallString<256> TyStr;
1840 llvm::raw_svector_ostream Out(TyStr);
1841 CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1842 Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1843 break;
1844 }
1845 case BlockCaptureEntityKind::ARCWeak:
1846 Str += "w";
1847 break;
1848 case BlockCaptureEntityKind::ARCStrong:
1849 Str += "s";
1850 break;
1851 case BlockCaptureEntityKind::BlockObject: {
1852 const VarDecl *Var = CI.getVariable();
1853 unsigned F = Flags.getBitMask();
1854 if (F & BLOCK_FIELD_IS_BYREF) {
1855 Str += "r";
1856 if (F & BLOCK_FIELD_IS_WEAK)
1857 Str += "w";
1858 else {
1859 // If CaptureStrKind::Merged is passed, check both the copy expression
1860 // and the destructor.
1861 if (StrKind != CaptureStrKind::DisposeHelper) {
1862 if (Ctx.getBlockVarCopyInit(Var).canThrow())
1863 Str += "c";
1864 }
1865 if (StrKind != CaptureStrKind::CopyHelper) {
1866 if (CodeGenFunction::cxxDestructorCanThrow(CaptureTy))
1867 Str += "d";
1868 }
1869 }
1870 } else {
1871 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1871, __PRETTY_FUNCTION__))
;
1872 if (F == BLOCK_FIELD_IS_BLOCK)
1873 Str += "b";
1874 else
1875 Str += "o";
1876 }
1877 break;
1878 }
1879 case BlockCaptureEntityKind::NonTrivialCStruct: {
1880 bool IsVolatile = CaptureTy.isVolatileQualified();
1881 CharUnits Alignment =
1882 BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1883
1884 Str += "n";
1885 std::string FuncStr;
1886 if (StrKind == CaptureStrKind::DisposeHelper)
1887 FuncStr = CodeGenFunction::getNonTrivialDestructorStr(
1888 CaptureTy, Alignment, IsVolatile, Ctx);
1889 else
1890 // If CaptureStrKind::Merged is passed, use the copy constructor string.
1891 // It has all the information that the destructor string has.
1892 FuncStr = CodeGenFunction::getNonTrivialCopyConstructorStr(
1893 CaptureTy, Alignment, IsVolatile, Ctx);
1894 // The underscore is necessary here because non-trivial copy constructor
1895 // and destructor strings can start with a number.
1896 Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1897 break;
1898 }
1899 case BlockCaptureEntityKind::None:
1900 break;
1901 }
1902
1903 return Str;
1904}
1905
1906static std::string getCopyDestroyHelperFuncName(
1907 const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1908 CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1909 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1911, __PRETTY_FUNCTION__))
1910 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1911, __PRETTY_FUNCTION__))
1911 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1911, __PRETTY_FUNCTION__))
;
1912 std::string Name = StrKind == CaptureStrKind::CopyHelper
1913 ? "__copy_helper_block_"
1914 : "__destroy_helper_block_";
1915 if (CGM.getLangOpts().Exceptions)
1916 Name += "e";
1917 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1918 Name += "a";
1919 Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1920
1921 for (const BlockCaptureManagedEntity &E : Captures) {
1922 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1923 Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1924 }
1925
1926 return Name;
1927}
1928
1929static void pushCaptureCleanup(BlockCaptureEntityKind CaptureKind,
1930 Address Field, QualType CaptureType,
1931 BlockFieldFlags Flags, bool ForCopyHelper,
1932 VarDecl *Var, CodeGenFunction &CGF) {
1933 bool EHOnly = ForCopyHelper;
1934
1935 switch (CaptureKind) {
1936 case BlockCaptureEntityKind::CXXRecord:
1937 case BlockCaptureEntityKind::ARCWeak:
1938 case BlockCaptureEntityKind::NonTrivialCStruct:
1939 case BlockCaptureEntityKind::ARCStrong: {
1940 if (CaptureType.isDestructedType() &&
1941 (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1942 CodeGenFunction::Destroyer *Destroyer =
1943 CaptureKind == BlockCaptureEntityKind::ARCStrong
1944 ? CodeGenFunction::destroyARCStrongImprecise
1945 : CGF.getDestroyer(CaptureType.isDestructedType());
1946 CleanupKind Kind =
1947 EHOnly ? EHCleanup
1948 : CGF.getCleanupKind(CaptureType.isDestructedType());
1949 CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1950 }
1951 break;
1952 }
1953 case BlockCaptureEntityKind::BlockObject: {
1954 if (!EHOnly || CGF.getLangOpts().Exceptions) {
1955 CleanupKind Kind = EHOnly ? EHCleanup : NormalAndEHCleanup;
1956 // Calls to _Block_object_dispose along the EH path in the copy helper
1957 // function don't throw as newly-copied __block variables always have a
1958 // reference count of 2.
1959 bool CanThrow =
1960 !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1961 CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1962 CanThrow);
1963 }
1964 break;
1965 }
1966 case BlockCaptureEntityKind::None:
1967 break;
1968 }
1969}
1970
1971static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType,
1972 llvm::Function *Fn,
1973 const CGFunctionInfo &FI,
1974 CodeGenModule &CGM) {
1975 if (CapturesNonExternalType) {
1976 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
1977 } else {
1978 Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1979 Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1980 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1981 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1982 }
1983}
1984/// Generate the copy-helper function for a block closure object:
1985/// static void block_copy_helper(block_t *dst, block_t *src);
1986/// The runtime will have previously initialized 'dst' by doing a
1987/// bit-copy of 'src'.
1988///
1989/// Note that this copies an entire block closure object to the heap;
1990/// it should not be confused with a 'byref copy helper', which moves
1991/// the contents of an individual __block variable to the heap.
1992llvm::Constant *
1993CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
1994 SmallVector<BlockCaptureManagedEntity, 4> CopiedCaptures;
1995 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
1996 std::string FuncName =
1997 getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
1998 CaptureStrKind::CopyHelper, CGM);
1999
2000 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2001 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2002
2003 ASTContext &C = getContext();
2004
2005 QualType ReturnTy = C.VoidTy;
2006
2007 FunctionArgList args;
2008 ImplicitParamDecl DstDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2009 args.push_back(&DstDecl);
2010 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2011 args.push_back(&SrcDecl);
2012
2013 const CGFunctionInfo &FI =
2014 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2015
2016 // FIXME: it would be nice if these were mergeable with things with
2017 // identical semantics.
2018 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2019
2020 llvm::Function *Fn =
2021 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2022 FuncName, &CGM.getModule());
2023 if (CGM.supportsCOMDAT())
2024 Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2025
2026 IdentifierInfo *II = &C.Idents.get(FuncName);
2027
2028 SmallVector<QualType, 2> ArgTys;
2029 ArgTys.push_back(C.VoidPtrTy);
2030 ArgTys.push_back(C.VoidPtrTy);
2031 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2032
2033 FunctionDecl *FD = FunctionDecl::Create(
2034 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
2035 FunctionTy, nullptr, SC_Static, false, false);
2036
2037 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2038 CGM);
2039 StartFunction(FD, ReturnTy, Fn, FI, args);
2040 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2041 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2042
2043 Address src = GetAddrOfLocalVar(&SrcDecl);
2044 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2045 src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2046
2047 Address dst = GetAddrOfLocalVar(&DstDecl);
2048 dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2049 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2050
2051 for (const auto &CopiedCapture : CopiedCaptures) {
2052 const BlockDecl::Capture &CI = *CopiedCapture.CI;
2053 const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2054 QualType captureType = CI.getVariable()->getType();
2055 BlockFieldFlags flags = CopiedCapture.CopyFlags;
2056
2057 unsigned index = capture.getIndex();
2058 Address srcField = Builder.CreateStructGEP(src, index);
2059 Address dstField = Builder.CreateStructGEP(dst, index);
2060
2061 switch (CopiedCapture.CopyKind) {
2062 case BlockCaptureEntityKind::CXXRecord:
2063 // If there's an explicit copy expression, we do that.
2064 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2064, __PRETTY_FUNCTION__))
;
2065 EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2066 break;
2067 case BlockCaptureEntityKind::ARCWeak:
2068 EmitARCCopyWeak(dstField, srcField);
2069 break;
2070 case BlockCaptureEntityKind::NonTrivialCStruct: {
2071 // If this is a C struct that requires non-trivial copy construction,
2072 // emit a call to its copy constructor.
2073 QualType varType = CI.getVariable()->getType();
2074 callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2075 MakeAddrLValue(srcField, varType));
2076 break;
2077 }
2078 case BlockCaptureEntityKind::ARCStrong: {
2079 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2080 // At -O0, store null into the destination field (so that the
2081 // storeStrong doesn't over-release) and then call storeStrong.
2082 // This is a workaround to not having an initStrong call.
2083 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2084 auto *ty = cast<llvm::PointerType>(srcValue->getType());
2085 llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2086 Builder.CreateStore(null, dstField);
2087 EmitARCStoreStrongCall(dstField, srcValue, true);
2088
2089 // With optimization enabled, take advantage of the fact that
2090 // the blocks runtime guarantees a memcpy of the block data, and
2091 // just emit a retain of the src field.
2092 } else {
2093 EmitARCRetainNonBlock(srcValue);
2094
2095 // Unless EH cleanup is required, we don't need this anymore, so kill
2096 // it. It's not quite worth the annoyance to avoid creating it in the
2097 // first place.
2098 if (!needsEHCleanup(captureType.isDestructedType()))
2099 cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2100 }
2101 break;
2102 }
2103 case BlockCaptureEntityKind::BlockObject: {
2104 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2105 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2106 llvm::Value *dstAddr =
2107 Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2108 llvm::Value *args[] = {
2109 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2110 };
2111
2112 if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2113 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2114 else
2115 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2116 break;
2117 }
2118 case BlockCaptureEntityKind::None:
2119 continue;
2120 }
2121
2122 // Ensure that we destroy the copied object if an exception is thrown later
2123 // in the helper function.
2124 pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2125 /*ForCopyHelper*/ true, CI.getVariable(), *this);
2126 }
2127
2128 FinishFunction();
2129
2130 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2131}
2132
2133static BlockFieldFlags
2134getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI,
2135 QualType T) {
2136 BlockFieldFlags Flags = BLOCK_FIELD_IS_OBJECT;
2137 if (T->isBlockPointerType())
2138 Flags = BLOCK_FIELD_IS_BLOCK;
2139 return Flags;
2140}
2141
2142static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2143computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
2144 const LangOptions &LangOpts) {
2145 if (CI.isEscapingByref()) {
2146 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2147 if (T.isObjCGCWeak())
2148 Flags |= BLOCK_FIELD_IS_WEAK;
2149 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2150 }
2151
2152 switch (T.isDestructedType()) {
2153 case QualType::DK_cxx_destructor:
2154 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2155 case QualType::DK_objc_strong_lifetime:
2156 // Use objc_storeStrong for __strong direct captures; the
2157 // dynamic tools really like it when we do this.
2158 return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2159 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2160 case QualType::DK_objc_weak_lifetime:
2161 // Support __weak direct captures.
2162 return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2163 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2164 case QualType::DK_nontrivial_c_struct:
2165 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2166 BlockFieldFlags());
2167 case QualType::DK_none: {
2168 // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2169 if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2170 !LangOpts.ObjCAutoRefCount)
2171 return std::make_pair(BlockCaptureEntityKind::BlockObject,
2172 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2173 // Otherwise, we have nothing to do.
2174 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2175 }
2176 }
2177 llvm_unreachable("after exhaustive DestructionKind switch")::llvm::llvm_unreachable_internal("after exhaustive DestructionKind switch"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2177)
;
2178}
2179
2180/// Generate the destroy-helper function for a block closure object:
2181/// static void block_destroy_helper(block_t *theBlock);
2182///
2183/// Note that this destroys a heap-allocated block closure object;
2184/// it should not be confused with a 'byref destroy helper', which
2185/// destroys the heap-allocated contents of an individual __block
2186/// variable.
2187llvm::Constant *
2188CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
2189 SmallVector<BlockCaptureManagedEntity, 4> DestroyedCaptures;
2190 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2191 std::string FuncName =
2192 getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2193 CaptureStrKind::DisposeHelper, CGM);
2194
2195 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2196 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2197
2198 ASTContext &C = getContext();
2199
2200 QualType ReturnTy = C.VoidTy;
2201
2202 FunctionArgList args;
2203 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2204 args.push_back(&SrcDecl);
2205
2206 const CGFunctionInfo &FI =
2207 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2208
2209 // FIXME: We'd like to put these into a mergable by content, with
2210 // internal linkage.
2211 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2212
2213 llvm::Function *Fn =
2214 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2215 FuncName, &CGM.getModule());
2216 if (CGM.supportsCOMDAT())
2217 Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2218
2219 IdentifierInfo *II = &C.Idents.get(FuncName);
2220
2221 SmallVector<QualType, 1> ArgTys;
2222 ArgTys.push_back(C.VoidPtrTy);
2223 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2224
2225 FunctionDecl *FD = FunctionDecl::Create(
2226 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
2227 FunctionTy, nullptr, SC_Static, false, false);
2228
2229 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2230 CGM);
2231 StartFunction(FD, ReturnTy, Fn, FI, args);
2232 markAsIgnoreThreadCheckingAtRuntime(Fn);
2233
2234 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2235
2236 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2237
2238 Address src = GetAddrOfLocalVar(&SrcDecl);
2239 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2240 src = Builder.CreateBitCast(src, structPtrTy, "block");
2241
2242 CodeGenFunction::RunCleanupsScope cleanups(*this);
2243
2244 for (const auto &DestroyedCapture : DestroyedCaptures) {
2245 const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2246 const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2247 BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2248
2249 Address srcField = Builder.CreateStructGEP(src, capture.getIndex());
2250
2251 pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2252 CI.getVariable()->getType(), flags,
2253 /*ForCopyHelper*/ false, CI.getVariable(), *this);
2254 }
2255
2256 cleanups.ForceCleanup();
2257
2258 FinishFunction();
2259
2260 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2261}
2262
2263namespace {
2264
2265/// Emits the copy/dispose helper functions for a __block object of id type.
2266class ObjectByrefHelpers final : public BlockByrefHelpers {
2267 BlockFieldFlags Flags;
2268
2269public:
2270 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2271 : BlockByrefHelpers(alignment), Flags(flags) {}
2272
2273 void emitCopy(CodeGenFunction &CGF, Address destField,
2274 Address srcField) override {
2275 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2276
2277 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2278 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2279
2280 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2281
2282 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2283 llvm::FunctionCallee fn = CGF.CGM.getBlockObjectAssign();
2284
2285 llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2286 CGF.EmitNounwindRuntimeCall(fn, args);
2287 }
2288
2289 void emitDispose(CodeGenFunction &CGF, Address field) override {
2290 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2291 llvm::Value *value = CGF.Builder.CreateLoad(field);
2292
2293 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2294 }
2295
2296 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2297 id.AddInteger(Flags.getBitMask());
2298 }
2299};
2300
2301/// Emits the copy/dispose helpers for an ARC __block __weak variable.
2302class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2303public:
2304 ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2305
2306 void emitCopy(CodeGenFunction &CGF, Address destField,
2307 Address srcField) override {
2308 CGF.EmitARCMoveWeak(destField, srcField);
2309 }
2310
2311 void emitDispose(CodeGenFunction &CGF, Address field) override {
2312 CGF.EmitARCDestroyWeak(field);
2313 }
2314
2315 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2316 // 0 is distinguishable from all pointers and byref flags
2317 id.AddInteger(0);
2318 }
2319};
2320
2321/// Emits the copy/dispose helpers for an ARC __block __strong variable
2322/// that's not of block-pointer type.
2323class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2324public:
2325 ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2326
2327 void emitCopy(CodeGenFunction &CGF, Address destField,
2328 Address srcField) override {
2329 // Do a "move" by copying the value and then zeroing out the old
2330 // variable.
2331
2332 llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2333
2334 llvm::Value *null =
2335 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2336
2337 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2338 CGF.Builder.CreateStore(null, destField);
2339 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2340 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2341 return;
2342 }
2343 CGF.Builder.CreateStore(value, destField);
2344 CGF.Builder.CreateStore(null, srcField);
2345 }
2346
2347 void emitDispose(CodeGenFunction &CGF, Address field) override {
2348 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2349 }
2350
2351 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2352 // 1 is distinguishable from all pointers and byref flags
2353 id.AddInteger(1);
2354 }
2355};
2356
2357/// Emits the copy/dispose helpers for an ARC __block __strong
2358/// variable that's of block-pointer type.
2359class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2360public:
2361 ARCStrongBlockByrefHelpers(CharUnits alignment)
2362 : BlockByrefHelpers(alignment) {}
2363
2364 void emitCopy(CodeGenFunction &CGF, Address destField,
2365 Address srcField) override {
2366 // Do the copy with objc_retainBlock; that's all that
2367 // _Block_object_assign would do anyway, and we'd have to pass the
2368 // right arguments to make sure it doesn't get no-op'ed.
2369 llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2370 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2371 CGF.Builder.CreateStore(copy, destField);
2372 }
2373
2374 void emitDispose(CodeGenFunction &CGF, Address field) override {
2375 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2376 }
2377
2378 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2379 // 2 is distinguishable from all pointers and byref flags
2380 id.AddInteger(2);
2381 }
2382};
2383
2384/// Emits the copy/dispose helpers for a __block variable with a
2385/// nontrivial copy constructor or destructor.
2386class CXXByrefHelpers final : public BlockByrefHelpers {
2387 QualType VarType;
2388 const Expr *CopyExpr;
2389
2390public:
2391 CXXByrefHelpers(CharUnits alignment, QualType type,
2392 const Expr *copyExpr)
2393 : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2394
2395 bool needsCopy() const override { return CopyExpr != nullptr; }
2396 void emitCopy(CodeGenFunction &CGF, Address destField,
2397 Address srcField) override {
2398 if (!CopyExpr) return;
2399 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2400 }
2401
2402 void emitDispose(CodeGenFunction &CGF, Address field) override {
2403 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2404 CGF.PushDestructorCleanup(VarType, field);
2405 CGF.PopCleanupBlocks(cleanupDepth);
2406 }
2407
2408 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2409 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2410 }
2411};
2412
2413/// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2414/// C struct.
2415class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2416 QualType VarType;
2417
2418public:
2419 NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2420 : BlockByrefHelpers(alignment), VarType(type) {}
2421
2422 void emitCopy(CodeGenFunction &CGF, Address destField,
2423 Address srcField) override {
2424 CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2425 CGF.MakeAddrLValue(srcField, VarType));
2426 }
2427
2428 bool needsDispose() const override {
2429 return VarType.isDestructedType();
2430 }
2431
2432 void emitDispose(CodeGenFunction &CGF, Address field) override {
2433 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2434 CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2435 CGF.PopCleanupBlocks(cleanupDepth);
2436 }
2437
2438 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2439 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2440 }
2441};
2442} // end anonymous namespace
2443
2444static llvm::Constant *
2445generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo,
2446 BlockByrefHelpers &generator) {
2447 ASTContext &Context = CGF.getContext();
2448
2449 QualType ReturnTy = Context.VoidTy;
2450
2451 FunctionArgList args;
2452 ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2453 args.push_back(&Dst);
2454
2455 ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2456 args.push_back(&Src);
2457
2458 const CGFunctionInfo &FI =
2459 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2460
2461 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2462
2463 // FIXME: We'd like to put these into a mergable by content, with
2464 // internal linkage.
2465 llvm::Function *Fn =
2466 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2467 "__Block_byref_object_copy_", &CGF.CGM.getModule());
2468
2469 IdentifierInfo *II
2470 = &Context.Idents.get("__Block_byref_object_copy_");
2471
2472 SmallVector<QualType, 2> ArgTys;
2473 ArgTys.push_back(Context.VoidPtrTy);
2474 ArgTys.push_back(Context.VoidPtrTy);
2475 QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2476
2477 FunctionDecl *FD = FunctionDecl::Create(
2478 Context, Context.getTranslationUnitDecl(), SourceLocation(),
2479 SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2480
2481 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2482
2483 CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2484
2485 if (generator.needsCopy()) {
2486 llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2487
2488 // dst->x
2489 Address destField = CGF.GetAddrOfLocalVar(&Dst);
2490 destField = Address(CGF.Builder.CreateLoad(destField),
2491 byrefInfo.ByrefAlignment);
2492 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2493 destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2494 "dest-object");
2495
2496 // src->x
2497 Address srcField = CGF.GetAddrOfLocalVar(&Src);
2498 srcField = Address(CGF.Builder.CreateLoad(srcField),
2499 byrefInfo.ByrefAlignment);
2500 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2501 srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2502 "src-object");
2503
2504 generator.emitCopy(CGF, destField, srcField);
2505 }
2506
2507 CGF.FinishFunction();
2508
2509 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2510}
2511
2512/// Build the copy helper for a __block variable.
2513static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2514 const BlockByrefInfo &byrefInfo,
2515 BlockByrefHelpers &generator) {
2516 CodeGenFunction CGF(CGM);
2517 return generateByrefCopyHelper(CGF, byrefInfo, generator);
2518}
2519
2520/// Generate code for a __block variable's dispose helper.
2521static llvm::Constant *
2522generateByrefDisposeHelper(CodeGenFunction &CGF,
2523 const BlockByrefInfo &byrefInfo,
2524 BlockByrefHelpers &generator) {
2525 ASTContext &Context = CGF.getContext();
2526 QualType R = Context.VoidTy;
2527
2528 FunctionArgList args;
2529 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2530 ImplicitParamDecl::Other);
2531 args.push_back(&Src);
2532
2533 const CGFunctionInfo &FI =
2534 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
2535
2536 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2537
2538 // FIXME: We'd like to put these into a mergable by content, with
2539 // internal linkage.
2540 llvm::Function *Fn =
2541 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2542 "__Block_byref_object_dispose_",
2543 &CGF.CGM.getModule());
2544
2545 IdentifierInfo *II
2546 = &Context.Idents.get("__Block_byref_object_dispose_");
2547
2548 SmallVector<QualType, 1> ArgTys;
2549 ArgTys.push_back(Context.VoidPtrTy);
2550 QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2551
2552 FunctionDecl *FD = FunctionDecl::Create(
2553 Context, Context.getTranslationUnitDecl(), SourceLocation(),
2554 SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2555
2556 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2557
2558 CGF.StartFunction(FD, R, Fn, FI, args);
2559
2560 if (generator.needsDispose()) {
2561 Address addr = CGF.GetAddrOfLocalVar(&Src);
2562 addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2563 auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2564 addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2565 addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2566
2567 generator.emitDispose(CGF, addr);
2568 }
2569
2570 CGF.FinishFunction();
2571
2572 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2573}
2574
2575/// Build the dispose helper for a __block variable.
2576static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2577 const BlockByrefInfo &byrefInfo,
2578 BlockByrefHelpers &generator) {
2579 CodeGenFunction CGF(CGM);
2580 return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2581}
2582
2583/// Lazily build the copy and dispose helpers for a __block variable
2584/// with the given information.
2585template <class T>
2586static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2587 T &&generator) {
2588 llvm::FoldingSetNodeID id;
2589 generator.Profile(id);
2590
2591 void *insertPos;
2592 BlockByrefHelpers *node
2593 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2594 if (node) return static_cast<T*>(node);
2595
2596 generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2597 generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2598
2599 T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2600 CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2601 return copy;
2602}
2603
2604/// Build the copy and dispose helpers for the given __block variable
2605/// emission. Places the helpers in the global cache. Returns null
2606/// if no helpers are required.
2607BlockByrefHelpers *
2608CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2609 const AutoVarEmission &emission) {
2610 const VarDecl &var = *emission.Variable;
2611 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2612, __PRETTY_FUNCTION__))
2612 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2612, __PRETTY_FUNCTION__))
;
2613
2614 QualType type = var.getType();
2615
2616 auto &byrefInfo = getBlockByrefInfo(&var);
2617
2618 // The alignment we care about for the purposes of uniquing byref
2619 // helpers is the alignment of the actual byref value field.
2620 CharUnits valueAlignment =
2621 byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2622
2623 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2624 const Expr *copyExpr =
2625 CGM.getContext().getBlockVarCopyInit(&var).getCopyExpr();
2626 if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2627
2628 return ::buildByrefHelpers(
2629 CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2630 }
2631
2632 // If type is a non-trivial C struct type that is non-trivial to
2633 // destructly move or destroy, build the copy and dispose helpers.
2634 if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2635 type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2636 return ::buildByrefHelpers(
2637 CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2638
2639 // Otherwise, if we don't have a retainable type, there's nothing to do.
2640 // that the runtime does extra copies.
2641 if (!type->isObjCRetainableType()) return nullptr;
2642
2643 Qualifiers qs = type.getQualifiers();
2644
2645 // If we have lifetime, that dominates.
2646 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2647 switch (lifetime) {
2648 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2648)
;
2649
2650 // These are just bits as far as the runtime is concerned.
2651 case Qualifiers::OCL_ExplicitNone:
2652 case Qualifiers::OCL_Autoreleasing:
2653 return nullptr;
2654
2655 // Tell the runtime that this is ARC __weak, called by the
2656 // byref routines.
2657 case Qualifiers::OCL_Weak:
2658 return ::buildByrefHelpers(CGM, byrefInfo,
2659 ARCWeakByrefHelpers(valueAlignment));
2660
2661 // ARC __strong __block variables need to be retained.
2662 case Qualifiers::OCL_Strong:
2663 // Block pointers need to be copied, and there's no direct
2664 // transfer possible.
2665 if (type->isBlockPointerType()) {
2666 return ::buildByrefHelpers(CGM, byrefInfo,
2667 ARCStrongBlockByrefHelpers(valueAlignment));
2668
2669 // Otherwise, we transfer ownership of the retain from the stack
2670 // to the heap.
2671 } else {
2672 return ::buildByrefHelpers(CGM, byrefInfo,
2673 ARCStrongByrefHelpers(valueAlignment));
2674 }
2675 }
2676 llvm_unreachable("fell out of lifetime switch!")::llvm::llvm_unreachable_internal("fell out of lifetime switch!"
, "/build/llvm-toolchain-snapshot-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2676)
;
2677 }
2678
2679 BlockFieldFlags flags;
2680 if (type->isBlockPointerType()) {
2681 flags |= BLOCK_FIELD_IS_BLOCK;
2682 } else if (CGM.getContext().isObjCNSObjectType(type) ||
2683 type->isObjCObjectPointerType()) {
2684 flags |= BLOCK_FIELD_IS_OBJECT;
2685 } else {
2686 return nullptr;
2687 }
2688
2689 if (type.isObjCGCWeak())
2690 flags |= BLOCK_FIELD_IS_WEAK;
2691
2692 return ::buildByrefHelpers(CGM, byrefInfo,
2693 ObjectByrefHelpers(valueAlignment, flags));
2694}
2695
2696Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2697 const VarDecl *var,
2698 bool followForward) {
2699 auto &info = getBlockByrefInfo(var);
2700 return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2701}
2702
2703Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2704 const BlockByrefInfo &info,
2705 bool followForward,
2706 const llvm::Twine &name) {
2707 // Chase the forwarding address if requested.
2708 if (followForward) {
2709 Address forwardingAddr = Builder.CreateStructGEP(baseAddr, 1, "forwarding");
2710 baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2711 }
2712
2713 return Builder.CreateStructGEP(baseAddr, info.FieldIndex, 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-10~svn373517/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, name);
2832 Builder.CreateStore(value, fieldAddr);
2833
2834 nextHeaderIndex++;
2835 nextHeaderOffset += fieldSize;
2836 };
2837
2838 // Build the byref helpers if necessary. This is null if we don't need any.
2839 BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2840
2841 const VarDecl &D = *emission.Variable;
2842 QualType type = D.getType();
2843
2844 bool HasByrefExtendedLayout;
2845 Qualifiers::ObjCLifetime ByrefLifetime;
2846 bool ByRefHasLifetime =
2847 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2848
2849 llvm::Value *V;
2850
2851 // Initialize the 'isa', which is just 0 or 1.
2852 int isa = 0;
2853 if (type.isObjCGCWeak())
2854 isa = 1;
2855 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2856 storeHeaderField(V, getPointerSize(), "byref.isa");
2857
2858 // Store the address of the variable into its own forwarding pointer.
2859 storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2860
2861 // Blocks ABI:
2862 // c) the flags field is set to either 0 if no helper functions are
2863 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2864 BlockFlags flags;
2865 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2866 if (ByRefHasLifetime) {
2867 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2868 else switch (ByrefLifetime) {
2869 case Qualifiers::OCL_Strong:
2870 flags |= BLOCK_BYREF_LAYOUT_STRONG;
2871 break;
2872 case Qualifiers::OCL_Weak:
2873 flags |= BLOCK_BYREF_LAYOUT_WEAK;
2874 break;
2875 case Qualifiers::OCL_ExplicitNone:
2876 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED;
2877 break;
2878 case Qualifiers::OCL_None:
2879 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2880 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT;
2881 break;
2882 default:
2883 break;
2884 }
2885 if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2886 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2887 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2888 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2889 if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2890 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2891 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2892 printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2893 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2894 printf(" BLOCK_BYREF_LAYOUT_STRONG");
2895 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2896 printf(" BLOCK_BYREF_LAYOUT_WEAK");
2897 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2898 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2899 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2900 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2901 }
2902 printf("\n");
2903 }
2904 }
2905 storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2906 getIntSize(), "byref.flags");
2907
2908 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2909 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2910 storeHeaderField(V, getIntSize(), "byref.size");
2911
2912 if (helpers) {
2913 storeHeaderField(helpers->CopyHelper, getPointerSize(),
2914 "byref.copyHelper");
2915 storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2916 "byref.disposeHelper");
2917 }
2918
2919 if (ByRefHasLifetime && HasByrefExtendedLayout) {
2920 auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2921 storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2922 }
2923}
2924
2925void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags,
2926 bool CanThrow) {
2927 llvm::FunctionCallee F = CGM.getBlockObjectDispose();
2928 llvm::Value *args[] = {
2929 Builder.CreateBitCast(V, Int8PtrTy),
2930 llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2931 };
2932
2933 if (CanThrow)
2934 EmitRuntimeCallOrInvoke(F, args);
2935 else
2936 EmitNounwindRuntimeCall(F, args);
2937}
2938
2939void CodeGenFunction::enterByrefCleanup(CleanupKind Kind, Address Addr,
2940 BlockFieldFlags Flags,
2941 bool LoadBlockVarAddr, bool CanThrow) {
2942 EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2943 CanThrow);
2944}
2945
2946/// Adjust the declaration of something from the blocks API.
2947static void configureBlocksRuntimeObject(CodeGenModule &CGM,
2948 llvm::Constant *C) {
2949 auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2950
2951 if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2952 IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2953 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2954 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2955
2956 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2958, __PRETTY_FUNCTION__))
2957 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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2958, __PRETTY_FUNCTION__))
2958 "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-10~svn373517/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2958, __PRETTY_FUNCTION__))
;
2959
2960 const NamedDecl *ND = nullptr;
2961 for (const auto &Result : DC->lookup(&II))
2962 if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2963 (ND = dyn_cast<VarDecl>(Result)))
2964 break;
2965
2966 // TODO: support static blocks runtime
2967 if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2968 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2969 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2970 } else {
2971 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2972 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2973 }
2974 }
2975
2976 if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2977 GV->hasExternalLinkage())
2978 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2979
2980 CGM.setDSOLocal(GV);
2981}
2982
2983llvm::FunctionCallee CodeGenModule::getBlockObjectDispose() {
2984 if (BlockObjectDispose)
2985 return BlockObjectDispose;
2986
2987 llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2988 llvm::FunctionType *fty
2989 = llvm::FunctionType::get(VoidTy, args, false);
2990 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2991 configureBlocksRuntimeObject(
2992 *this, cast<llvm::Constant>(BlockObjectDispose.getCallee()));
2993 return BlockObjectDispose;
2994}
2995
2996llvm::FunctionCallee 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(
3005 *this, cast<llvm::Constant>(BlockObjectAssign.getCallee()));
3006 return BlockObjectAssign;
3007}
3008
3009llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
3010 if (NSConcreteGlobalBlock)
3011 return NSConcreteGlobalBlock;
3012
3013 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3014 Int8PtrTy->getPointerTo(),
3015 nullptr);
3016 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3017 return NSConcreteGlobalBlock;
3018}
3019
3020llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
3021 if (NSConcreteStackBlock)
3022 return NSConcreteStackBlock;
3023
3024 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3025 Int8PtrTy->getPointerTo(),
3026 nullptr);
3027 configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3028 return NSConcreteStackBlock;
3029}