Bug Summary

File:tools/clang/lib/CodeGen/CGBlocks.cpp
Warning:line 579, column 7
Forming reference to null pointer

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGBlocks.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D 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-8~svn350071/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn350071/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-8~svn350071=. -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 -o /tmp/scan-build-2018-12-27-042839-1215-1 -x c++ /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp -faddrsig
1//===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit blocks.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CGBlocks.h"
15#include "CGCXXABI.h"
16#include "CGDebugInfo.h"
17#include "CGObjCRuntime.h"
18#include "CGOpenCLRuntime.h"
19#include "CodeGenFunction.h"
20#include "CodeGenModule.h"
21#include "ConstantEmitter.h"
22#include "TargetInfo.h"
23#include "clang/AST/DeclObjC.h"
24#include "clang/CodeGen/ConstantInitBuilder.h"
25#include "llvm/ADT/SmallSet.h"
26#include "llvm/IR/CallSite.h"
27#include "llvm/IR/DataLayout.h"
28#include "llvm/IR/Module.h"
29#include "llvm/Support/ScopedPrinter.h"
30#include <algorithm>
31#include <cstdio>
32
33using namespace clang;
34using namespace CodeGen;
35
36CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
37 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
38 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
39 CapturesNonExternalType(false), LocalAddress(Address::invalid()),
40 StructureType(nullptr), Block(block), DominatingIP(nullptr) {
41
42 // Skip asm prefix, if any. 'name' is usually taken directly from
43 // the mangled name of the enclosing function.
44 if (!name.empty() && name[0] == '\01')
45 name = name.substr(1);
46}
47
48// Anchor the vtable to this translation unit.
49BlockByrefHelpers::~BlockByrefHelpers() {}
50
51/// Build the given block as a global block.
52static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
53 const CGBlockInfo &blockInfo,
54 llvm::Constant *blockFn);
55
56/// Build the helper function to copy a block.
57static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
58 const CGBlockInfo &blockInfo) {
59 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
60}
61
62/// Build the helper function to dispose of a block.
63static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
64 const CGBlockInfo &blockInfo) {
65 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
66}
67
68namespace {
69
70/// Represents a type of copy/destroy operation that should be performed for an
71/// entity that's captured by a block.
72enum class BlockCaptureEntityKind {
73 CXXRecord, // Copy or destroy
74 ARCWeak,
75 ARCStrong,
76 NonTrivialCStruct,
77 BlockObject, // Assign or release
78 None
79};
80
81/// Represents a captured entity that requires extra operations in order for
82/// this entity to be copied or destroyed correctly.
83struct BlockCaptureManagedEntity {
84 BlockCaptureEntityKind CopyKind, DisposeKind;
85 BlockFieldFlags CopyFlags, DisposeFlags;
86 const BlockDecl::Capture *CI;
87 const CGBlockInfo::Capture *Capture;
88
89 BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
90 BlockCaptureEntityKind DisposeType,
91 BlockFieldFlags CopyFlags,
92 BlockFieldFlags DisposeFlags,
93 const BlockDecl::Capture &CI,
94 const CGBlockInfo::Capture &Capture)
95 : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
96 DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
97
98 bool operator<(const BlockCaptureManagedEntity &Other) const {
99 return Capture->getOffset() < Other.Capture->getOffset();
100 }
101};
102
103enum class CaptureStrKind {
104 // String for the copy helper.
105 CopyHelper,
106 // String for the dispose helper.
107 DisposeHelper,
108 // Merge the strings for the copy helper and dispose helper.
109 Merged
110};
111
112} // end anonymous namespace
113
114static void findBlockCapturedManagedEntities(
115 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
116 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
117
118static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
119 CaptureStrKind StrKind,
120 CharUnits BlockAlignment,
121 CodeGenModule &CGM);
122
123static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
124 CodeGenModule &CGM) {
125 std::string Name = "__block_descriptor_";
126 Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
127
128 if (BlockInfo.needsCopyDisposeHelpers()) {
129 if (CGM.getLangOpts().Exceptions)
130 Name += "e";
131 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
132 Name += "a";
133 Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
134
135 SmallVector<BlockCaptureManagedEntity, 4> ManagedCaptures;
136 findBlockCapturedManagedEntities(BlockInfo, CGM.getContext().getLangOpts(),
137 ManagedCaptures);
138
139 for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
140 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
141
142 if (E.CopyKind == E.DisposeKind) {
143 // If CopyKind and DisposeKind are the same, merge the capture
144 // information.
145 assert(E.CopyKind != BlockCaptureEntityKind::None &&((E.CopyKind != BlockCaptureEntityKind::None && "shouldn't see BlockCaptureManagedEntity that is None"
) ? static_cast<void> (0) : __assert_fail ("E.CopyKind != BlockCaptureEntityKind::None && \"shouldn't see BlockCaptureManagedEntity that is None\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 146, __PRETTY_FUNCTION__))
146 "shouldn't see BlockCaptureManagedEntity that is None")((E.CopyKind != BlockCaptureEntityKind::None && "shouldn't see BlockCaptureManagedEntity that is None"
) ? static_cast<void> (0) : __assert_fail ("E.CopyKind != BlockCaptureEntityKind::None && \"shouldn't see BlockCaptureManagedEntity that is None\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 146, __PRETTY_FUNCTION__))
;
147 Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
148 BlockInfo.BlockAlign, CGM);
149 } else {
150 // If CopyKind and DisposeKind are not the same, which can happen when
151 // either Kind is None or the captured object is a __strong block,
152 // concatenate the copy and dispose strings.
153 Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
154 BlockInfo.BlockAlign, CGM);
155 Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
156 BlockInfo.BlockAlign, CGM);
157 }
158 }
159 Name += "_";
160 }
161
162 std::string TypeAtEncoding =
163 CGM.getContext().getObjCEncodingForBlock(BlockInfo.getBlockExpr());
164 Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
165 Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
166 return Name;
167}
168
169/// buildBlockDescriptor - Build the block descriptor meta-data for a block.
170/// buildBlockDescriptor is accessed from 5th field of the Block_literal
171/// meta-data and contains stationary information about the block literal.
172/// Its definition will have 4 (or optionally 6) words.
173/// \code
174/// struct Block_descriptor {
175/// unsigned long reserved;
176/// unsigned long size; // size of Block_literal metadata in bytes.
177/// void *copy_func_helper_decl; // optional copy helper.
178/// void *destroy_func_decl; // optional destructor helper.
179/// void *block_method_encoding_address; // @encode for block literal signature.
180/// void *block_layout_info; // encoding of captured block variables.
181/// };
182/// \endcode
183static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
184 const CGBlockInfo &blockInfo) {
185 ASTContext &C = CGM.getContext();
186
187 llvm::IntegerType *ulong =
188 cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
189 llvm::PointerType *i8p = nullptr;
190 if (CGM.getLangOpts().OpenCL)
191 i8p =
192 llvm::Type::getInt8PtrTy(
193 CGM.getLLVMContext(), C.getTargetAddressSpace(LangAS::opencl_constant));
194 else
195 i8p = CGM.VoidPtrTy;
196
197 std::string descName;
198
199 // If an equivalent block descriptor global variable exists, return it.
200 if (C.getLangOpts().ObjC &&
201 CGM.getLangOpts().getGC() == LangOptions::NonGC) {
202 descName = getBlockDescriptorName(blockInfo, CGM);
203 if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
204 return llvm::ConstantExpr::getBitCast(desc,
205 CGM.getBlockDescriptorType());
206 }
207
208 // If there isn't an equivalent block descriptor global variable, create a new
209 // one.
210 ConstantInitBuilder builder(CGM);
211 auto elements = builder.beginStruct();
212
213 // reserved
214 elements.addInt(ulong, 0);
215
216 // Size
217 // FIXME: What is the right way to say this doesn't fit? We should give
218 // a user diagnostic in that case. Better fix would be to change the
219 // API to size_t.
220 elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
221
222 // Optional copy/dispose helpers.
223 bool hasInternalHelper = false;
224 if (blockInfo.needsCopyDisposeHelpers()) {
225 // copy_func_helper_decl
226 llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
227 elements.add(copyHelper);
228
229 // destroy_func_decl
230 llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
231 elements.add(disposeHelper);
232
233 if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
234 cast<llvm::Function>(disposeHelper->getOperand(0))
235 ->hasInternalLinkage())
236 hasInternalHelper = true;
237 }
238
239 // Signature. Mandatory ObjC-style method descriptor @encode sequence.
240 std::string typeAtEncoding =
241 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr());
242 elements.add(llvm::ConstantExpr::getBitCast(
243 CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
244
245 // GC layout.
246 if (C.getLangOpts().ObjC) {
247 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
248 elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
249 else
250 elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
251 }
252 else
253 elements.addNullPointer(i8p);
254
255 unsigned AddrSpace = 0;
256 if (C.getLangOpts().OpenCL)
257 AddrSpace = C.getTargetAddressSpace(LangAS::opencl_constant);
258
259 llvm::GlobalValue::LinkageTypes linkage;
260 if (descName.empty()) {
261 linkage = llvm::GlobalValue::InternalLinkage;
262 descName = "__block_descriptor_tmp";
263 } else if (hasInternalHelper) {
264 // If either the copy helper or the dispose helper has internal linkage,
265 // the block descriptor must have internal linkage too.
266 linkage = llvm::GlobalValue::InternalLinkage;
267 } else {
268 linkage = llvm::GlobalValue::LinkOnceODRLinkage;
269 }
270
271 llvm::GlobalVariable *global =
272 elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
273 /*constant*/ true, linkage, AddrSpace);
274
275 if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
276 global->setVisibility(llvm::GlobalValue::HiddenVisibility);
277 global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
278 }
279
280 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
281}
282
283/*
284 Purely notional variadic template describing the layout of a block.
285
286 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
287 struct Block_literal {
288 /// Initialized to one of:
289 /// extern void *_NSConcreteStackBlock[];
290 /// extern void *_NSConcreteGlobalBlock[];
291 ///
292 /// In theory, we could start one off malloc'ed by setting
293 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
294 /// this isa:
295 /// extern void *_NSConcreteMallocBlock[];
296 struct objc_class *isa;
297
298 /// These are the flags (with corresponding bit number) that the
299 /// compiler is actually supposed to know about.
300 /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
301 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
302 /// descriptor provides copy and dispose helper functions
303 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
304 /// object with a nontrivial destructor or copy constructor
305 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
306 /// as global memory
307 /// 29. BLOCK_USE_STRET - indicates that the block function
308 /// uses stret, which objc_msgSend needs to know about
309 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
310 /// @encoded signature string
311 /// And we're not supposed to manipulate these:
312 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
313 /// to malloc'ed memory
314 /// 27. BLOCK_IS_GC - indicates that the block has been moved to
315 /// to GC-allocated memory
316 /// Additionally, the bottom 16 bits are a reference count which
317 /// should be zero on the stack.
318 int flags;
319
320 /// Reserved; should be zero-initialized.
321 int reserved;
322
323 /// Function pointer generated from block literal.
324 _ResultType (*invoke)(Block_literal *, _ParamTypes...);
325
326 /// Block description metadata generated from block literal.
327 struct Block_descriptor *block_descriptor;
328
329 /// Captured values follow.
330 _CapturesTypes captures...;
331 };
332 */
333
334namespace {
335 /// A chunk of data that we actually have to capture in the block.
336 struct BlockLayoutChunk {
337 CharUnits Alignment;
338 CharUnits Size;
339 Qualifiers::ObjCLifetime Lifetime;
340 const BlockDecl::Capture *Capture; // null for 'this'
341 llvm::Type *Type;
342 QualType FieldType;
343
344 BlockLayoutChunk(CharUnits align, CharUnits size,
345 Qualifiers::ObjCLifetime lifetime,
346 const BlockDecl::Capture *capture,
347 llvm::Type *type, QualType fieldType)
348 : Alignment(align), Size(size), Lifetime(lifetime),
349 Capture(capture), Type(type), FieldType(fieldType) {}
350
351 /// Tell the block info that this chunk has the given field index.
352 void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
353 if (!Capture) {
354 info.CXXThisIndex = index;
355 info.CXXThisOffset = offset;
356 } else {
357 auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
358 info.Captures.insert({Capture->getVariable(), C});
359 }
360 }
361 };
362
363 /// Order by 1) all __strong together 2) next, all byfref together 3) next,
364 /// all __weak together. Preserve descending alignment in all situations.
365 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
366 if (left.Alignment != right.Alignment)
367 return left.Alignment > right.Alignment;
368
369 auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
370 if (chunk.Capture && chunk.Capture->isByRef())
371 return 1;
372 if (chunk.Lifetime == Qualifiers::OCL_Strong)
373 return 0;
374 if (chunk.Lifetime == Qualifiers::OCL_Weak)
375 return 2;
376 return 3;
377 };
378
379 return getPrefOrder(left) < getPrefOrder(right);
380 }
381} // end anonymous namespace
382
383/// Determines if the given type is safe for constant capture in C++.
384static bool isSafeForCXXConstantCapture(QualType type) {
385 const RecordType *recordType =
386 type->getBaseElementTypeUnsafe()->getAs<RecordType>();
387
388 // Only records can be unsafe.
389 if (!recordType) return true;
390
391 const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
392
393 // Maintain semantics for classes with non-trivial dtors or copy ctors.
394 if (!record->hasTrivialDestructor()) return false;
395 if (record->hasNonTrivialCopyConstructor()) return false;
396
397 // Otherwise, we just have to make sure there aren't any mutable
398 // fields that might have changed since initialization.
399 return !record->hasMutableFields();
400}
401
402/// It is illegal to modify a const object after initialization.
403/// Therefore, if a const object has a constant initializer, we don't
404/// actually need to keep storage for it in the block; we'll just
405/// rematerialize it at the start of the block function. This is
406/// acceptable because we make no promises about address stability of
407/// captured variables.
408static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
409 CodeGenFunction *CGF,
410 const VarDecl *var) {
411 // Return if this is a function parameter. We shouldn't try to
412 // rematerialize default arguments of function parameters.
413 if (isa<ParmVarDecl>(var))
414 return nullptr;
415
416 QualType type = var->getType();
417
418 // We can only do this if the variable is const.
419 if (!type.isConstQualified()) return nullptr;
420
421 // Furthermore, in C++ we have to worry about mutable fields:
422 // C++ [dcl.type.cv]p4:
423 // Except that any class member declared mutable can be
424 // modified, any attempt to modify a const object during its
425 // lifetime results in undefined behavior.
426 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
427 return nullptr;
428
429 // If the variable doesn't have any initializer (shouldn't this be
430 // invalid?), it's not clear what we should do. Maybe capture as
431 // zero?
432 const Expr *init = var->getInit();
433 if (!init) return nullptr;
434
435 return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
436}
437
438/// Get the low bit of a nonzero character count. This is the
439/// alignment of the nth byte if the 0th byte is universally aligned.
440static CharUnits getLowBit(CharUnits v) {
441 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
442}
443
444static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
445 SmallVectorImpl<llvm::Type*> &elementTypes) {
446
447 assert(elementTypes.empty())((elementTypes.empty()) ? static_cast<void> (0) : __assert_fail
("elementTypes.empty()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 447, __PRETTY_FUNCTION__))
;
448 if (CGM.getLangOpts().OpenCL) {
449 // The header is basically 'struct { int; int; generic void *;
450 // custom_fields; }'. Assert that struct is packed.
451 auto GenericAS =
452 CGM.getContext().getTargetAddressSpace(LangAS::opencl_generic);
453 auto GenPtrAlign =
454 CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
455 auto GenPtrSize =
456 CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
457 assert(CGM.getIntSize() <= GenPtrSize)((CGM.getIntSize() <= GenPtrSize) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntSize() <= GenPtrSize", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 457, __PRETTY_FUNCTION__))
;
458 assert(CGM.getIntAlign() <= GenPtrAlign)((CGM.getIntAlign() <= GenPtrAlign) ? static_cast<void>
(0) : __assert_fail ("CGM.getIntAlign() <= GenPtrAlign", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 458, __PRETTY_FUNCTION__))
;
459 assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign))(((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign)) ? static_cast
<void> (0) : __assert_fail ("(2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign)"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 459, __PRETTY_FUNCTION__))
;
460 elementTypes.push_back(CGM.IntTy); /* total size */
461 elementTypes.push_back(CGM.IntTy); /* align */
462 elementTypes.push_back(
463 CGM.getOpenCLRuntime()
464 .getGenericVoidPointerType()); /* invoke function */
465 unsigned Offset =
466 2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
467 unsigned BlockAlign = GenPtrAlign.getQuantity();
468 if (auto *Helper =
469 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
470 for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
471 // TargetOpenCLBlockHelp needs to make sure the struct is packed.
472 // If necessary, add padding fields to the custom fields.
473 unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
474 if (BlockAlign < Align)
475 BlockAlign = Align;
476 assert(Offset % Align == 0)((Offset % Align == 0) ? static_cast<void> (0) : __assert_fail
("Offset % Align == 0", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 476, __PRETTY_FUNCTION__))
;
477 Offset += CGM.getDataLayout().getTypeAllocSize(I);
478 elementTypes.push_back(I);
479 }
480 }
481 info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
482 info.BlockSize = CharUnits::fromQuantity(Offset);
483 } else {
484 // The header is basically 'struct { void *; int; int; void *; void *; }'.
485 // Assert that the struct is packed.
486 assert(CGM.getIntSize() <= CGM.getPointerSize())((CGM.getIntSize() <= CGM.getPointerSize()) ? static_cast<
void> (0) : __assert_fail ("CGM.getIntSize() <= CGM.getPointerSize()"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 486, __PRETTY_FUNCTION__))
;
487 assert(CGM.getIntAlign() <= CGM.getPointerAlign())((CGM.getIntAlign() <= CGM.getPointerAlign()) ? static_cast
<void> (0) : __assert_fail ("CGM.getIntAlign() <= CGM.getPointerAlign()"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 487, __PRETTY_FUNCTION__))
;
488 assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()))(((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()))
? static_cast<void> (0) : __assert_fail ("(2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign())"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 488, __PRETTY_FUNCTION__))
;
489 info.BlockAlign = CGM.getPointerAlign();
490 info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
491 elementTypes.push_back(CGM.VoidPtrTy);
492 elementTypes.push_back(CGM.IntTy);
493 elementTypes.push_back(CGM.IntTy);
494 elementTypes.push_back(CGM.VoidPtrTy);
495 elementTypes.push_back(CGM.getBlockDescriptorType());
496 }
497}
498
499static QualType getCaptureFieldType(const CodeGenFunction &CGF,
500 const BlockDecl::Capture &CI) {
501 const VarDecl *VD = CI.getVariable();
502
503 // If the variable is captured by an enclosing block or lambda expression,
504 // use the type of the capture field.
505 if (CGF.BlockInfo && CI.isNested())
506 return CGF.BlockInfo->getCapture(VD).fieldType();
507 if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
508 return FD->getType();
509 // If the captured variable is a non-escaping __block variable, the field
510 // type is the reference type. If the variable is a __block variable that
511 // already has a reference type, the field type is the variable's type.
512 return VD->isNonEscapingByref() ?
513 CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
514}
515
516/// Compute the layout of the given block. Attempts to lay the block
517/// out with minimal space requirements.
518static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF,
519 CGBlockInfo &info) {
520 ASTContext &C = CGM.getContext();
521 const BlockDecl *block = info.getBlockDecl();
522
523 SmallVector<llvm::Type*, 8> elementTypes;
524 initializeForBlockHeader(CGM, info, elementTypes);
525 bool hasNonConstantCustomFields = false;
526 if (auto *OpenCLHelper =
5
Assuming 'OpenCLHelper' is null
6
Taking false branch
527 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper())
528 hasNonConstantCustomFields =
529 !OpenCLHelper->areAllCustomFieldValuesConstant(info);
530 if (!block->hasCaptures() && !hasNonConstantCustomFields) {
531 info.StructureType =
532 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
533 info.CanBeGlobal = true;
534 return;
535 }
536 else if (C.getLangOpts().ObjC &&
7
Assuming the condition is false
537 CGM.getLangOpts().getGC() == LangOptions::NonGC)
538 info.HasCapturedVariableLayout = true;
539
540 // Collect the layout chunks.
541 SmallVector<BlockLayoutChunk, 16> layout;
542 layout.reserve(block->capturesCXXThis() +
543 (block->capture_end() - block->capture_begin()));
544
545 CharUnits maxFieldAlign;
546
547 // First, 'this'.
548 if (block->capturesCXXThis()) {
8
Assuming the condition is false
9
Taking false branch
549 assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&((CGF && CGF->CurFuncDecl && isa<CXXMethodDecl
>(CGF->CurFuncDecl) && "Can't capture 'this' outside a method"
) ? static_cast<void> (0) : __assert_fail ("CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && \"Can't capture 'this' outside a method\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 550, __PRETTY_FUNCTION__))
550 "Can't capture 'this' outside a method")((CGF && CGF->CurFuncDecl && isa<CXXMethodDecl
>(CGF->CurFuncDecl) && "Can't capture 'this' outside a method"
) ? static_cast<void> (0) : __assert_fail ("CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) && \"Can't capture 'this' outside a method\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 550, __PRETTY_FUNCTION__))
;
551 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
552
553 // Theoretically, this could be in a different address space, so
554 // don't assume standard pointer size/align.
555 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
556 std::pair<CharUnits,CharUnits> tinfo
557 = CGM.getContext().getTypeInfoInChars(thisType);
558 maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
559
560 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
561 Qualifiers::OCL_None,
562 nullptr, llvmType, thisType));
563 }
564
565 // Next, all the block captures.
566 for (const auto &CI : block->captures()) {
10
Assuming '__begin1' is not equal to '__end1'
567 const VarDecl *variable = CI.getVariable();
568
569 if (CI.isEscapingByref()) {
11
Assuming the condition is true
12
Taking true branch
570 // We have to copy/dispose of the __block reference.
571 info.NeedsCopyDispose = true;
572
573 // Just use void* instead of a pointer to the byref type.
574 CharUnits align = CGM.getPointerAlign();
575 maxFieldAlign = std::max(maxFieldAlign, align);
576
577 // Since a __block variable cannot be captured by lambdas, its type and
578 // the capture field type should always match.
579 assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&((getCaptureFieldType(*CGF, CI) == variable->getType() &&
"capture type differs from the variable type") ? static_cast
<void> (0) : __assert_fail ("getCaptureFieldType(*CGF, CI) == variable->getType() && \"capture type differs from the variable type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 580, __PRETTY_FUNCTION__))
13
Forming reference to null pointer
580 "capture type differs from the variable type")((getCaptureFieldType(*CGF, CI) == variable->getType() &&
"capture type differs from the variable type") ? static_cast
<void> (0) : __assert_fail ("getCaptureFieldType(*CGF, CI) == variable->getType() && \"capture type differs from the variable type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 580, __PRETTY_FUNCTION__))
;
581 layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
582 Qualifiers::OCL_None, &CI,
583 CGM.VoidPtrTy, variable->getType()));
584 continue;
585 }
586
587 // Otherwise, build a layout chunk with the size and alignment of
588 // the declaration.
589 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
590 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
591 continue;
592 }
593
594 QualType VT = getCaptureFieldType(*CGF, CI);
595
596 // If we have a lifetime qualifier, honor it for capture purposes.
597 // That includes *not* copying it if it's __unsafe_unretained.
598 Qualifiers::ObjCLifetime lifetime = VT.getObjCLifetime();
599 if (lifetime) {
600 switch (lifetime) {
601 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 601)
;
602 case Qualifiers::OCL_ExplicitNone:
603 case Qualifiers::OCL_Autoreleasing:
604 break;
605
606 case Qualifiers::OCL_Strong:
607 case Qualifiers::OCL_Weak:
608 info.NeedsCopyDispose = true;
609 }
610
611 // Block pointers require copy/dispose. So do Objective-C pointers.
612 } else if (VT->isObjCRetainableType()) {
613 // But honor the inert __unsafe_unretained qualifier, which doesn't
614 // actually make it into the type system.
615 if (VT->isObjCInertUnsafeUnretainedType()) {
616 lifetime = Qualifiers::OCL_ExplicitNone;
617 } else {
618 info.NeedsCopyDispose = true;
619 // used for mrr below.
620 lifetime = Qualifiers::OCL_Strong;
621 }
622
623 // So do types that require non-trivial copy construction.
624 } else if (CI.hasCopyExpr()) {
625 info.NeedsCopyDispose = true;
626 info.HasCXXObject = true;
627 if (!VT->getAsCXXRecordDecl()->isExternallyVisible())
628 info.CapturesNonExternalType = true;
629
630 // So do C structs that require non-trivial copy construction or
631 // destruction.
632 } else if (VT.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct ||
633 VT.isDestructedType() == QualType::DK_nontrivial_c_struct) {
634 info.NeedsCopyDispose = true;
635
636 // And so do types with destructors.
637 } else if (CGM.getLangOpts().CPlusPlus) {
638 if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
639 if (!record->hasTrivialDestructor()) {
640 info.HasCXXObject = true;
641 info.NeedsCopyDispose = true;
642 if (!record->isExternallyVisible())
643 info.CapturesNonExternalType = true;
644 }
645 }
646 }
647
648 CharUnits size = C.getTypeSizeInChars(VT);
649 CharUnits align = C.getDeclAlign(variable);
650
651 maxFieldAlign = std::max(maxFieldAlign, align);
652
653 llvm::Type *llvmType =
654 CGM.getTypes().ConvertTypeForMem(VT);
655
656 layout.push_back(
657 BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
658 }
659
660 // If that was everything, we're done here.
661 if (layout.empty()) {
662 info.StructureType =
663 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
664 info.CanBeGlobal = true;
665 return;
666 }
667
668 // Sort the layout by alignment. We have to use a stable sort here
669 // to get reproducible results. There should probably be an
670 // llvm::array_pod_stable_sort.
671 std::stable_sort(layout.begin(), layout.end());
672
673 // Needed for blocks layout info.
674 info.BlockHeaderForcedGapOffset = info.BlockSize;
675 info.BlockHeaderForcedGapSize = CharUnits::Zero();
676
677 CharUnits &blockSize = info.BlockSize;
678 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
679
680 // Assuming that the first byte in the header is maximally aligned,
681 // get the alignment of the first byte following the header.
682 CharUnits endAlign = getLowBit(blockSize);
683
684 // If the end of the header isn't satisfactorily aligned for the
685 // maximum thing, look for things that are okay with the header-end
686 // alignment, and keep appending them until we get something that's
687 // aligned right. This algorithm is only guaranteed optimal if
688 // that condition is satisfied at some point; otherwise we can get
689 // things like:
690 // header // next byte has alignment 4
691 // something_with_size_5; // next byte has alignment 1
692 // something_with_alignment_8;
693 // which has 7 bytes of padding, as opposed to the naive solution
694 // which might have less (?).
695 if (endAlign < maxFieldAlign) {
696 SmallVectorImpl<BlockLayoutChunk>::iterator
697 li = layout.begin() + 1, le = layout.end();
698
699 // Look for something that the header end is already
700 // satisfactorily aligned for.
701 for (; li != le && endAlign < li->Alignment; ++li)
702 ;
703
704 // If we found something that's naturally aligned for the end of
705 // the header, keep adding things...
706 if (li != le) {
707 SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
708 for (; li != le; ++li) {
709 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 709, __PRETTY_FUNCTION__))
;
710
711 li->setIndex(info, elementTypes.size(), blockSize);
712 elementTypes.push_back(li->Type);
713 blockSize += li->Size;
714 endAlign = getLowBit(blockSize);
715
716 // ...until we get to the alignment of the maximum field.
717 if (endAlign >= maxFieldAlign) {
718 break;
719 }
720 }
721 // Don't re-append everything we just appended.
722 layout.erase(first, li);
723 }
724 }
725
726 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 726, __PRETTY_FUNCTION__))
;
727
728 // At this point, we just have to add padding if the end align still
729 // isn't aligned right.
730 if (endAlign < maxFieldAlign) {
731 CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
732 CharUnits padding = newBlockSize - blockSize;
733
734 // If we haven't yet added any fields, remember that there was an
735 // initial gap; this need to go into the block layout bit map.
736 if (blockSize == info.BlockHeaderForcedGapOffset) {
737 info.BlockHeaderForcedGapSize = padding;
738 }
739
740 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
741 padding.getQuantity()));
742 blockSize = newBlockSize;
743 endAlign = getLowBit(blockSize); // might be > maxFieldAlign
744 }
745
746 assert(endAlign >= maxFieldAlign)((endAlign >= maxFieldAlign) ? static_cast<void> (0)
: __assert_fail ("endAlign >= maxFieldAlign", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 746, __PRETTY_FUNCTION__))
;
747 assert(endAlign == getLowBit(blockSize))((endAlign == getLowBit(blockSize)) ? static_cast<void>
(0) : __assert_fail ("endAlign == getLowBit(blockSize)", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 747, __PRETTY_FUNCTION__))
;
748 // Slam everything else on now. This works because they have
749 // strictly decreasing alignment and we expect that size is always a
750 // multiple of alignment.
751 for (SmallVectorImpl<BlockLayoutChunk>::iterator
752 li = layout.begin(), le = layout.end(); li != le; ++li) {
753 if (endAlign < li->Alignment) {
754 // size may not be multiple of alignment. This can only happen with
755 // an over-aligned variable. We will be adding a padding field to
756 // make the size be multiple of alignment.
757 CharUnits padding = li->Alignment - endAlign;
758 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
759 padding.getQuantity()));
760 blockSize += padding;
761 endAlign = getLowBit(blockSize);
762 }
763 assert(endAlign >= li->Alignment)((endAlign >= li->Alignment) ? static_cast<void> (
0) : __assert_fail ("endAlign >= li->Alignment", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 763, __PRETTY_FUNCTION__))
;
764 li->setIndex(info, elementTypes.size(), blockSize);
765 elementTypes.push_back(li->Type);
766 blockSize += li->Size;
767 endAlign = getLowBit(blockSize);
768 }
769
770 info.StructureType =
771 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
772}
773
774/// Enter the scope of a block. This should be run at the entrance to
775/// a full-expression so that the block's cleanups are pushed at the
776/// right place in the stack.
777static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
778 assert(CGF.HaveInsertPoint())((CGF.HaveInsertPoint()) ? static_cast<void> (0) : __assert_fail
("CGF.HaveInsertPoint()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 778, __PRETTY_FUNCTION__))
;
779
780 // Allocate the block info and place it at the head of the list.
781 CGBlockInfo &blockInfo =
782 *new CGBlockInfo(block, CGF.CurFn->getName());
783 blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
784 CGF.FirstBlockInfo = &blockInfo;
785
786 // Compute information about the layout, etc., of this block,
787 // pushing cleanups as necessary.
788 computeBlockInfo(CGF.CGM, &CGF, blockInfo);
789
790 // Nothing else to do if it can be global.
791 if (blockInfo.CanBeGlobal) return;
792
793 // Make the allocation for the block.
794 blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
795 blockInfo.BlockAlign, "block");
796
797 // If there are cleanups to emit, enter them (but inactive).
798 if (!blockInfo.NeedsCopyDispose) return;
799
800 // Walk through the captures (in order) and find the ones not
801 // captured by constant.
802 for (const auto &CI : block->captures()) {
803 // Ignore __block captures; there's nothing special in the
804 // on-stack block that we need to do for them.
805 if (CI.isByRef()) continue;
806
807 // Ignore variables that are constant-captured.
808 const VarDecl *variable = CI.getVariable();
809 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
810 if (capture.isConstant()) continue;
811
812 // Ignore objects that aren't destructed.
813 QualType VT = getCaptureFieldType(CGF, CI);
814 QualType::DestructionKind dtorKind = VT.isDestructedType();
815 if (dtorKind == QualType::DK_none) continue;
816
817 CodeGenFunction::Destroyer *destroyer;
818
819 // Block captures count as local values and have imprecise semantics.
820 // They also can't be arrays, so need to worry about that.
821 //
822 // For const-qualified captures, emit clang.arc.use to ensure the captured
823 // object doesn't get released while we are still depending on its validity
824 // within the block.
825 if (VT.isConstQualified() &&
826 VT.getObjCLifetime() == Qualifiers::OCL_Strong &&
827 CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
828 assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&((CGF.CGM.getLangOpts().ObjCAutoRefCount && "expected ObjC ARC to be enabled"
) ? static_cast<void> (0) : __assert_fail ("CGF.CGM.getLangOpts().ObjCAutoRefCount && \"expected ObjC ARC to be enabled\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 829, __PRETTY_FUNCTION__))
829 "expected ObjC ARC to be enabled")((CGF.CGM.getLangOpts().ObjCAutoRefCount && "expected ObjC ARC to be enabled"
) ? static_cast<void> (0) : __assert_fail ("CGF.CGM.getLangOpts().ObjCAutoRefCount && \"expected ObjC ARC to be enabled\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 829, __PRETTY_FUNCTION__))
;
830 destroyer = CodeGenFunction::emitARCIntrinsicUse;
831 } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
832 destroyer = CodeGenFunction::destroyARCStrongImprecise;
833 } else {
834 destroyer = CGF.getDestroyer(dtorKind);
835 }
836
837 // GEP down to the address.
838 Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
839 capture.getIndex(),
840 capture.getOffset());
841
842 // We can use that GEP as the dominating IP.
843 if (!blockInfo.DominatingIP)
844 blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
845
846 CleanupKind cleanupKind = InactiveNormalCleanup;
847 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
848 if (useArrayEHCleanup)
849 cleanupKind = InactiveNormalAndEHCleanup;
850
851 CGF.pushDestroy(cleanupKind, addr, VT,
852 destroyer, useArrayEHCleanup);
853
854 // Remember where that cleanup was.
855 capture.setCleanup(CGF.EHStack.stable_begin());
856 }
857}
858
859/// Enter a full-expression with a non-trivial number of objects to
860/// clean up. This is in this file because, at the moment, the only
861/// kind of cleanup object is a BlockDecl*.
862void CodeGenFunction::enterNonTrivialFullExpression(const FullExpr *E) {
863 if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
864 assert(EWC->getNumObjects() != 0)((EWC->getNumObjects() != 0) ? static_cast<void> (0)
: __assert_fail ("EWC->getNumObjects() != 0", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 864, __PRETTY_FUNCTION__))
;
865 for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
866 enterBlockScope(*this, C);
867 }
868}
869
870/// Find the layout for the given block in a linked list and remove it.
871static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head,
872 const BlockDecl *block) {
873 while (true) {
874 assert(head && *head)((head && *head) ? static_cast<void> (0) : __assert_fail
("head && *head", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 874, __PRETTY_FUNCTION__))
;
875 CGBlockInfo *cur = *head;
876
877 // If this is the block we're looking for, splice it out of the list.
878 if (cur->getBlockDecl() == block) {
879 *head = cur->NextBlockInfo;
880 return cur;
881 }
882
883 head = &cur->NextBlockInfo;
884 }
885}
886
887/// Destroy a chain of block layouts.
888void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) {
889 assert(head && "destroying an empty chain")((head && "destroying an empty chain") ? static_cast<
void> (0) : __assert_fail ("head && \"destroying an empty chain\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 889, __PRETTY_FUNCTION__))
;
890 do {
891 CGBlockInfo *cur = head;
892 head = cur->NextBlockInfo;
893 delete cur;
894 } while (head != nullptr);
895}
896
897/// Emit a block literal expression in the current function.
898llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
899 // If the block has no captures, we won't have a pre-computed
900 // layout for it.
901 if (!blockExpr->getBlockDecl()->hasCaptures()) {
902 // The block literal is emitted as a global variable, and the block invoke
903 // function has to be extracted from its initializer.
904 if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
905 return Block;
906 }
907 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
908 computeBlockInfo(CGM, this, blockInfo);
909 blockInfo.BlockExpression = blockExpr;
910 return EmitBlockLiteral(blockInfo);
911 }
912
913 // Find the block info for this block and take ownership of it.
914 std::unique_ptr<CGBlockInfo> blockInfo;
915 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
916 blockExpr->getBlockDecl()));
917
918 blockInfo->BlockExpression = blockExpr;
919 return EmitBlockLiteral(*blockInfo);
920}
921
922llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
923 bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
924 auto GenVoidPtrTy =
925 IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
926 LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
927 auto GenVoidPtrSize = CharUnits::fromQuantity(
928 CGM.getTarget().getPointerWidth(
929 CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
930 8);
931 // Using the computed layout, generate the actual block function.
932 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
933 CodeGenFunction BlockCGF{CGM, true};
934 BlockCGF.SanOpts = SanOpts;
935 auto *InvokeFn = BlockCGF.GenerateBlockFunction(
936 CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
937 auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
938
939 // If there is nothing to capture, we can emit this as a global block.
940 if (blockInfo.CanBeGlobal)
941 return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
942
943 // Otherwise, we have to emit this as a local block.
944
945 Address blockAddr = blockInfo.LocalAddress;
946 assert(blockAddr.isValid() && "block has no address!")((blockAddr.isValid() && "block has no address!") ? static_cast
<void> (0) : __assert_fail ("blockAddr.isValid() && \"block has no address!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 946, __PRETTY_FUNCTION__))
;
947
948 llvm::Constant *isa;
949 llvm::Constant *descriptor;
950 BlockFlags flags;
951 if (!IsOpenCL) {
952 // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
953 // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
954 // block just returns the original block and releasing it is a no-op.
955 llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
956 ? CGM.getNSConcreteGlobalBlock()
957 : CGM.getNSConcreteStackBlock();
958 isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
959
960 // Build the block descriptor.
961 descriptor = buildBlockDescriptor(CGM, blockInfo);
962
963 // Compute the initial on-stack block flags.
964 flags = BLOCK_HAS_SIGNATURE;
965 if (blockInfo.HasCapturedVariableLayout)
966 flags |= BLOCK_HAS_EXTENDED_LAYOUT;
967 if (blockInfo.needsCopyDisposeHelpers())
968 flags |= BLOCK_HAS_COPY_DISPOSE;
969 if (blockInfo.HasCXXObject)
970 flags |= BLOCK_HAS_CXX_OBJ;
971 if (blockInfo.UsesStret)
972 flags |= BLOCK_USE_STRET;
973 if (blockInfo.getBlockDecl()->doesNotEscape())
974 flags |= BLOCK_IS_NOESCAPE | BLOCK_IS_GLOBAL;
975 }
976
977 auto projectField =
978 [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
979 return Builder.CreateStructGEP(blockAddr, index, offset, name);
980 };
981 auto storeField =
982 [&](llvm::Value *value, unsigned index, CharUnits offset,
983 const Twine &name) {
984 Builder.CreateStore(value, projectField(index, offset, name));
985 };
986
987 // Initialize the block header.
988 {
989 // We assume all the header fields are densely packed.
990 unsigned index = 0;
991 CharUnits offset;
992 auto addHeaderField =
993 [&](llvm::Value *value, CharUnits size, const Twine &name) {
994 storeField(value, index, offset, name);
995 offset += size;
996 index++;
997 };
998
999 if (!IsOpenCL) {
1000 addHeaderField(isa, getPointerSize(), "block.isa");
1001 addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1002 getIntSize(), "block.flags");
1003 addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1004 "block.reserved");
1005 } else {
1006 addHeaderField(
1007 llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1008 getIntSize(), "block.size");
1009 addHeaderField(
1010 llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1011 getIntSize(), "block.align");
1012 }
1013 addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1014 if (!IsOpenCL)
1015 addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1016 else if (auto *Helper =
1017 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1018 for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1019 addHeaderField(
1020 I.first,
1021 CharUnits::fromQuantity(
1022 CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1023 I.second);
1024 }
1025 }
1026 }
1027
1028 // Finally, capture all the values into the block.
1029 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1030
1031 // First, 'this'.
1032 if (blockDecl->capturesCXXThis()) {
1033 Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
1034 "block.captured-this.addr");
1035 Builder.CreateStore(LoadCXXThis(), addr);
1036 }
1037
1038 // Next, captured variables.
1039 for (const auto &CI : blockDecl->captures()) {
1040 const VarDecl *variable = CI.getVariable();
1041 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1042
1043 // Ignore constant captures.
1044 if (capture.isConstant()) continue;
1045
1046 QualType type = capture.fieldType();
1047
1048 // This will be a [[type]]*, except that a byref entry will just be
1049 // an i8**.
1050 Address blockField =
1051 projectField(capture.getIndex(), capture.getOffset(), "block.captured");
1052
1053 // Compute the address of the thing we're going to move into the
1054 // block literal.
1055 Address src = Address::invalid();
1056
1057 if (blockDecl->isConversionFromLambda()) {
1058 // The lambda capture in a lambda's conversion-to-block-pointer is
1059 // special; we'll simply emit it directly.
1060 src = Address::invalid();
1061 } else if (CI.isEscapingByref()) {
1062 if (BlockInfo && CI.isNested()) {
1063 // We need to use the capture from the enclosing block.
1064 const CGBlockInfo::Capture &enclosingCapture =
1065 BlockInfo->getCapture(variable);
1066
1067 // This is a [[type]]*, except that a byref entry will just be an i8**.
1068 src = Builder.CreateStructGEP(LoadBlockStruct(),
1069 enclosingCapture.getIndex(),
1070 enclosingCapture.getOffset(),
1071 "block.capture.addr");
1072 } else {
1073 auto I = LocalDeclMap.find(variable);
1074 assert(I != LocalDeclMap.end())((I != LocalDeclMap.end()) ? static_cast<void> (0) : __assert_fail
("I != LocalDeclMap.end()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1074, __PRETTY_FUNCTION__))
;
1075 src = I->second;
1076 }
1077 } else {
1078 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1079 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1080 type.getNonReferenceType(), VK_LValue,
1081 SourceLocation());
1082 src = EmitDeclRefLValue(&declRef).getAddress();
1083 };
1084
1085 // For byrefs, we just write the pointer to the byref struct into
1086 // the block field. There's no need to chase the forwarding
1087 // pointer at this point, since we're building something that will
1088 // live a shorter life than the stack byref anyway.
1089 if (CI.isEscapingByref()) {
1090 // Get a void* that points to the byref struct.
1091 llvm::Value *byrefPointer;
1092 if (CI.isNested())
1093 byrefPointer = Builder.CreateLoad(src, "byref.capture");
1094 else
1095 byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1096
1097 // Write that void* into the capture field.
1098 Builder.CreateStore(byrefPointer, blockField);
1099
1100 // If we have a copy constructor, evaluate that into the block field.
1101 } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1102 if (blockDecl->isConversionFromLambda()) {
1103 // If we have a lambda conversion, emit the expression
1104 // directly into the block instead.
1105 AggValueSlot Slot =
1106 AggValueSlot::forAddr(blockField, Qualifiers(),
1107 AggValueSlot::IsDestructed,
1108 AggValueSlot::DoesNotNeedGCBarriers,
1109 AggValueSlot::IsNotAliased,
1110 AggValueSlot::DoesNotOverlap);
1111 EmitAggExpr(copyExpr, Slot);
1112 } else {
1113 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1114 }
1115
1116 // If it's a reference variable, copy the reference into the block field.
1117 } else if (type->isReferenceType()) {
1118 Builder.CreateStore(src.getPointer(), blockField);
1119
1120 // If type is const-qualified, copy the value into the block field.
1121 } else if (type.isConstQualified() &&
1122 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1123 CGM.getCodeGenOpts().OptimizationLevel != 0) {
1124 llvm::Value *value = Builder.CreateLoad(src, "captured");
1125 Builder.CreateStore(value, blockField);
1126
1127 // If this is an ARC __strong block-pointer variable, don't do a
1128 // block copy.
1129 //
1130 // TODO: this can be generalized into the normal initialization logic:
1131 // we should never need to do a block-copy when initializing a local
1132 // variable, because the local variable's lifetime should be strictly
1133 // contained within the stack block's.
1134 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1135 type->isBlockPointerType()) {
1136 // Load the block and do a simple retain.
1137 llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1138 value = EmitARCRetainNonBlock(value);
1139
1140 // Do a primitive store to the block field.
1141 Builder.CreateStore(value, blockField);
1142
1143 // Otherwise, fake up a POD copy into the block field.
1144 } else {
1145 // Fake up a new variable so that EmitScalarInit doesn't think
1146 // we're referring to the variable in its own initializer.
1147 ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1148 ImplicitParamDecl::Other);
1149
1150 // We use one of these or the other depending on whether the
1151 // reference is nested.
1152 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1153 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1154 type, VK_LValue, SourceLocation());
1155
1156 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1157 &declRef, VK_RValue);
1158 // FIXME: Pass a specific location for the expr init so that the store is
1159 // attributed to a reasonable location - otherwise it may be attributed to
1160 // locations of subexpressions in the initialization.
1161 EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1162 MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1163 /*captured by init*/ false);
1164 }
1165
1166 // Activate the cleanup if layout pushed one.
1167 if (!CI.isByRef()) {
1168 EHScopeStack::stable_iterator cleanup = capture.getCleanup();
1169 if (cleanup.isValid())
1170 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1171 }
1172 }
1173
1174 // Cast to the converted block-pointer type, which happens (somewhat
1175 // unfortunately) to be a pointer to function type.
1176 llvm::Value *result = Builder.CreatePointerCast(
1177 blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1178
1179 if (IsOpenCL) {
1180 CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1181 result);
1182 }
1183
1184 return result;
1185}
1186
1187
1188llvm::Type *CodeGenModule::getBlockDescriptorType() {
1189 if (BlockDescriptorType)
1190 return BlockDescriptorType;
1191
1192 llvm::Type *UnsignedLongTy =
1193 getTypes().ConvertType(getContext().UnsignedLongTy);
1194
1195 // struct __block_descriptor {
1196 // unsigned long reserved;
1197 // unsigned long block_size;
1198 //
1199 // // later, the following will be added
1200 //
1201 // struct {
1202 // void (*copyHelper)();
1203 // void (*copyHelper)();
1204 // } helpers; // !!! optional
1205 //
1206 // const char *signature; // the block signature
1207 // const char *layout; // reserved
1208 // };
1209 BlockDescriptorType = llvm::StructType::create(
1210 "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1211
1212 // Now form a pointer to that.
1213 unsigned AddrSpace = 0;
1214 if (getLangOpts().OpenCL)
1215 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1216 BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1217 return BlockDescriptorType;
1218}
1219
1220llvm::Type *CodeGenModule::getGenericBlockLiteralType() {
1221 if (GenericBlockLiteralType)
1222 return GenericBlockLiteralType;
1223
1224 llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1225
1226 if (getLangOpts().OpenCL) {
1227 // struct __opencl_block_literal_generic {
1228 // int __size;
1229 // int __align;
1230 // __generic void *__invoke;
1231 // /* custom fields */
1232 // };
1233 SmallVector<llvm::Type *, 8> StructFields(
1234 {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1235 if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1236 for (auto I : Helper->getCustomFieldTypes())
1237 StructFields.push_back(I);
1238 }
1239 GenericBlockLiteralType = llvm::StructType::create(
1240 StructFields, "struct.__opencl_block_literal_generic");
1241 } else {
1242 // struct __block_literal_generic {
1243 // void *__isa;
1244 // int __flags;
1245 // int __reserved;
1246 // void (*__invoke)(void *);
1247 // struct __block_descriptor *__descriptor;
1248 // };
1249 GenericBlockLiteralType =
1250 llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1251 IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1252 }
1253
1254 return GenericBlockLiteralType;
1255}
1256
1257RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E,
1258 ReturnValueSlot ReturnValue) {
1259 const BlockPointerType *BPT =
1260 E->getCallee()->getType()->getAs<BlockPointerType>();
1261
1262 llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1263
1264 // Get a pointer to the generic block literal.
1265 // For OpenCL we generate generic AS void ptr to be able to reuse the same
1266 // block definition for blocks with captures generated as private AS local
1267 // variables and without captures generated as global AS program scope
1268 // variables.
1269 unsigned AddrSpace = 0;
1270 if (getLangOpts().OpenCL)
1271 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1272
1273 llvm::Type *BlockLiteralTy =
1274 llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1275
1276 // Bitcast the callee to a block literal.
1277 BlockPtr =
1278 Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1279
1280 // Get the function pointer from the literal.
1281 llvm::Value *FuncPtr =
1282 Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr,
1283 CGM.getLangOpts().OpenCL ? 2 : 3);
1284
1285 // Add the block literal.
1286 CallArgList Args;
1287
1288 QualType VoidPtrQualTy = getContext().VoidPtrTy;
1289 llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1290 if (getLangOpts().OpenCL) {
1291 GenericVoidPtrTy = CGM.getOpenCLRuntime().getGenericVoidPointerType();
1292 VoidPtrQualTy =
1293 getContext().getPointerType(getContext().getAddrSpaceQualType(
1294 getContext().VoidTy, LangAS::opencl_generic));
1295 }
1296
1297 BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1298 Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1299
1300 QualType FnType = BPT->getPointeeType();
1301
1302 // And the rest of the arguments.
1303 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1304
1305 // Load the function.
1306 llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1307
1308 const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1309 const CGFunctionInfo &FnInfo =
1310 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1311
1312 // Cast the function pointer to the right type.
1313 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1314
1315 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1316 Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1317
1318 // Prepare the callee.
1319 CGCallee Callee(CGCalleeInfo(), Func);
1320
1321 // And call the block.
1322 return EmitCall(FnInfo, Callee, ReturnValue, Args);
1323}
1324
1325Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable) {
1326 assert(BlockInfo && "evaluating block ref without block information?")((BlockInfo && "evaluating block ref without block information?"
) ? static_cast<void> (0) : __assert_fail ("BlockInfo && \"evaluating block ref without block information?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1326, __PRETTY_FUNCTION__))
;
1327 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1328
1329 // Handle constant captures.
1330 if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1331
1332 Address addr =
1333 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1334 capture.getOffset(), "block.capture.addr");
1335
1336 if (variable->isEscapingByref()) {
1337 // addr should be a void** right now. Load, then cast the result
1338 // to byref*.
1339
1340 auto &byrefInfo = getBlockByrefInfo(variable);
1341 addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1342
1343 auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1344 addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1345
1346 addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1347 variable->getName());
1348 }
1349
1350 assert((!variable->isNonEscapingByref() ||(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1353, __PRETTY_FUNCTION__))
1351 capture.fieldType()->isReferenceType()) &&(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1353, __PRETTY_FUNCTION__))
1352 "the capture field of a non-escaping variable should have a "(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1353, __PRETTY_FUNCTION__))
1353 "reference type")(((!variable->isNonEscapingByref() || capture.fieldType()->
isReferenceType()) && "the capture field of a non-escaping variable should have a "
"reference type") ? static_cast<void> (0) : __assert_fail
("(!variable->isNonEscapingByref() || capture.fieldType()->isReferenceType()) && \"the capture field of a non-escaping variable should have a \" \"reference type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1353, __PRETTY_FUNCTION__))
;
1354 if (capture.fieldType()->isReferenceType())
1355 addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1356
1357 return addr;
1358}
1359
1360void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
1361 llvm::Constant *Addr) {
1362 bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1363 (void)Ok;
1364 assert(Ok && "Trying to replace an already-existing global block!")((Ok && "Trying to replace an already-existing global block!"
) ? static_cast<void> (0) : __assert_fail ("Ok && \"Trying to replace an already-existing global block!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1364, __PRETTY_FUNCTION__))
;
1365}
1366
1367llvm::Constant *
1368CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
1369 StringRef Name) {
1370 if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1
Assuming 'Block' is null
2
Taking false branch
1371 return Block;
1372
1373 CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1374 blockInfo.BlockExpression = BE;
1375
1376 // Compute information about the layout, etc., of this block.
1377 computeBlockInfo(*this, nullptr, blockInfo);
3
Passing null pointer value via 2nd parameter 'CGF'
4
Calling 'computeBlockInfo'
1378
1379 // Using that metadata, generate the actual block function.
1380 {
1381 CodeGenFunction::DeclMapTy LocalDeclMap;
1382 CodeGenFunction(*this).GenerateBlockFunction(
1383 GlobalDecl(), blockInfo, LocalDeclMap,
1384 /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1385 }
1386
1387 return getAddrOfGlobalBlockIfEmitted(BE);
1388}
1389
1390static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1391 const CGBlockInfo &blockInfo,
1392 llvm::Constant *blockFn) {
1393 assert(blockInfo.CanBeGlobal)((blockInfo.CanBeGlobal) ? static_cast<void> (0) : __assert_fail
("blockInfo.CanBeGlobal", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1393, __PRETTY_FUNCTION__))
;
1394 // Callers should detect this case on their own: calling this function
1395 // generally requires computing layout information, which is a waste of time
1396 // if we've already emitted this block.
1397 assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&((!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression
) && "Refusing to re-emit a global block.") ? static_cast
<void> (0) : __assert_fail ("!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) && \"Refusing to re-emit a global block.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1398, __PRETTY_FUNCTION__))
1398 "Refusing to re-emit a global block.")((!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression
) && "Refusing to re-emit a global block.") ? static_cast
<void> (0) : __assert_fail ("!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) && \"Refusing to re-emit a global block.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1398, __PRETTY_FUNCTION__))
;
1399
1400 // Generate the constants for the block literal initializer.
1401 ConstantInitBuilder builder(CGM);
1402 auto fields = builder.beginStruct();
1403
1404 bool IsOpenCL = CGM.getLangOpts().OpenCL;
1405 bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1406 if (!IsOpenCL) {
1407 // isa
1408 if (IsWindows)
1409 fields.addNullPointer(CGM.Int8PtrPtrTy);
1410 else
1411 fields.add(CGM.getNSConcreteGlobalBlock());
1412
1413 // __flags
1414 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE;
1415 if (blockInfo.UsesStret)
1416 flags |= BLOCK_USE_STRET;
1417
1418 fields.addInt(CGM.IntTy, flags.getBitMask());
1419
1420 // Reserved
1421 fields.addInt(CGM.IntTy, 0);
1422 } else {
1423 fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1424 fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1425 }
1426
1427 // Function
1428 fields.add(blockFn);
1429
1430 if (!IsOpenCL) {
1431 // Descriptor
1432 fields.add(buildBlockDescriptor(CGM, blockInfo));
1433 } else if (auto *Helper =
1434 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1435 for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1436 fields.add(I);
1437 }
1438 }
1439
1440 unsigned AddrSpace = 0;
1441 if (CGM.getContext().getLangOpts().OpenCL)
1442 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
1443
1444 llvm::Constant *literal = fields.finishAndCreateGlobal(
1445 "__block_literal_global", blockInfo.BlockAlign,
1446 /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1447
1448 // Windows does not allow globals to be initialised to point to globals in
1449 // different DLLs. Any such variables must run code to initialise them.
1450 if (IsWindows) {
1451 auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1452 {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1453 &CGM.getModule());
1454 llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1455 Init));
1456 b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1457 b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1458 b.CreateRetVoid();
1459 // We can't use the normal LLVM global initialisation array, because we
1460 // need to specify that this runs early in library initialisation.
1461 auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1462 /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1463 Init, ".block_isa_init_ptr");
1464 InitVar->setSection(".CRT$XCLa");
1465 CGM.addUsedGlobal(InitVar);
1466 }
1467
1468 // Return a constant of the appropriately-casted type.
1469 llvm::Type *RequiredType =
1470 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1471 llvm::Constant *Result =
1472 llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1473 CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1474 if (CGM.getContext().getLangOpts().OpenCL)
1475 CGM.getOpenCLRuntime().recordBlockInfo(
1476 blockInfo.BlockExpression,
1477 cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1478 return Result;
1479}
1480
1481void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,
1482 unsigned argNum,
1483 llvm::Value *arg) {
1484 assert(BlockInfo && "not emitting prologue of block invocation function?!")((BlockInfo && "not emitting prologue of block invocation function?!"
) ? static_cast<void> (0) : __assert_fail ("BlockInfo && \"not emitting prologue of block invocation function?!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1484, __PRETTY_FUNCTION__))
;
1485
1486 // Allocate a stack slot like for any local variable to guarantee optimal
1487 // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1488 Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1489 Builder.CreateStore(arg, alloc);
1490 if (CGDebugInfo *DI = getDebugInfo()) {
1491 if (CGM.getCodeGenOpts().getDebugInfo() >=
1492 codegenoptions::LimitedDebugInfo) {
1493 DI->setLocation(D->getLocation());
1494 DI->EmitDeclareOfBlockLiteralArgVariable(
1495 *BlockInfo, D->getName(), argNum,
1496 cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1497 }
1498 }
1499
1500 SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1501 ApplyDebugLocation Scope(*this, StartLoc);
1502
1503 // Instead of messing around with LocalDeclMap, just set the value
1504 // directly as BlockPointer.
1505 BlockPointer = Builder.CreatePointerCast(
1506 arg,
1507 BlockInfo->StructureType->getPointerTo(
1508 getContext().getLangOpts().OpenCL
1509 ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1510 : 0),
1511 "block");
1512}
1513
1514Address CodeGenFunction::LoadBlockStruct() {
1515 assert(BlockInfo && "not in a block invocation function!")((BlockInfo && "not in a block invocation function!")
? static_cast<void> (0) : __assert_fail ("BlockInfo && \"not in a block invocation function!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1515, __PRETTY_FUNCTION__))
;
1516 assert(BlockPointer && "no block pointer set!")((BlockPointer && "no block pointer set!") ? static_cast
<void> (0) : __assert_fail ("BlockPointer && \"no block pointer set!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1516, __PRETTY_FUNCTION__))
;
1517 return Address(BlockPointer, BlockInfo->BlockAlign);
1518}
1519
1520llvm::Function *
1521CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
1522 const CGBlockInfo &blockInfo,
1523 const DeclMapTy &ldm,
1524 bool IsLambdaConversionToBlock,
1525 bool BuildGlobalBlock) {
1526 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1527
1528 CurGD = GD;
1529
1530 CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1531
1532 BlockInfo = &blockInfo;
1533
1534 // Arrange for local static and local extern declarations to appear
1535 // to be local to this function as well, in case they're directly
1536 // referenced in a block.
1537 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1538 const auto *var = dyn_cast<VarDecl>(i->first);
1539 if (var && !var->hasLocalStorage())
1540 setAddrOfLocalVar(var, i->second);
1541 }
1542
1543 // Begin building the function declaration.
1544
1545 // Build the argument list.
1546 FunctionArgList args;
1547
1548 // The first argument is the block pointer. Just take it as a void*
1549 // and cast it later.
1550 QualType selfTy = getContext().VoidPtrTy;
1551
1552 // For OpenCL passed block pointer can be private AS local variable or
1553 // global AS program scope variable (for the case with and without captures).
1554 // Generic AS is used therefore to be able to accommodate both private and
1555 // generic AS in one implementation.
1556 if (getLangOpts().OpenCL)
1557 selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1558 getContext().VoidTy, LangAS::opencl_generic));
1559
1560 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1561
1562 ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1563 SourceLocation(), II, selfTy,
1564 ImplicitParamDecl::ObjCSelf);
1565 args.push_back(&SelfDecl);
1566
1567 // Now add the rest of the parameters.
1568 args.append(blockDecl->param_begin(), blockDecl->param_end());
1569
1570 // Create the function declaration.
1571 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1572 const CGFunctionInfo &fnInfo =
1573 CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1574 if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1575 blockInfo.UsesStret = true;
1576
1577 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1578
1579 StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1580 llvm::Function *fn = llvm::Function::Create(
1581 fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1582 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1583
1584 if (BuildGlobalBlock) {
1585 auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1586 ? CGM.getOpenCLRuntime().getGenericVoidPointerType()
1587 : VoidPtrTy;
1588 buildGlobalBlock(CGM, blockInfo,
1589 llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1590 }
1591
1592 // Begin generating the function.
1593 StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1594 blockDecl->getLocation(),
1595 blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1596
1597 // Okay. Undo some of what StartFunction did.
1598
1599 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1600 // won't delete the dbg.declare intrinsics for captured variables.
1601 llvm::Value *BlockPointerDbgLoc = BlockPointer;
1602 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1603 // Allocate a stack slot for it, so we can point the debugger to it
1604 Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1605 getPointerAlign(),
1606 "block.addr");
1607 // Set the DebugLocation to empty, so the store is recognized as a
1608 // frame setup instruction by llvm::DwarfDebug::beginFunction().
1609 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1610 Builder.CreateStore(BlockPointer, Alloca);
1611 BlockPointerDbgLoc = Alloca.getPointer();
1612 }
1613
1614 // If we have a C++ 'this' reference, go ahead and force it into
1615 // existence now.
1616 if (blockDecl->capturesCXXThis()) {
1617 Address addr =
1618 Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1619 blockInfo.CXXThisOffset, "block.captured-this");
1620 CXXThisValue = Builder.CreateLoad(addr, "this");
1621 }
1622
1623 // Also force all the constant captures.
1624 for (const auto &CI : blockDecl->captures()) {
1625 const VarDecl *variable = CI.getVariable();
1626 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1627 if (!capture.isConstant()) continue;
1628
1629 CharUnits align = getContext().getDeclAlign(variable);
1630 Address alloca =
1631 CreateMemTemp(variable->getType(), align, "block.captured-const");
1632
1633 Builder.CreateStore(capture.getConstant(), alloca);
1634
1635 setAddrOfLocalVar(variable, alloca);
1636 }
1637
1638 // Save a spot to insert the debug information for all the DeclRefExprs.
1639 llvm::BasicBlock *entry = Builder.GetInsertBlock();
1640 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1641 --entry_ptr;
1642
1643 if (IsLambdaConversionToBlock)
1644 EmitLambdaBlockInvokeBody();
1645 else {
1646 PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1647 incrementProfileCounter(blockDecl->getBody());
1648 EmitStmt(blockDecl->getBody());
1649 }
1650
1651 // Remember where we were...
1652 llvm::BasicBlock *resume = Builder.GetInsertBlock();
1653
1654 // Go back to the entry.
1655 ++entry_ptr;
1656 Builder.SetInsertPoint(entry, entry_ptr);
1657
1658 // Emit debug information for all the DeclRefExprs.
1659 // FIXME: also for 'this'
1660 if (CGDebugInfo *DI = getDebugInfo()) {
1661 for (const auto &CI : blockDecl->captures()) {
1662 const VarDecl *variable = CI.getVariable();
1663 DI->EmitLocation(Builder, variable->getLocation());
1664
1665 if (CGM.getCodeGenOpts().getDebugInfo() >=
1666 codegenoptions::LimitedDebugInfo) {
1667 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1668 if (capture.isConstant()) {
1669 auto addr = LocalDeclMap.find(variable)->second;
1670 (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1671 Builder);
1672 continue;
1673 }
1674
1675 DI->EmitDeclareOfBlockDeclRefVariable(
1676 variable, BlockPointerDbgLoc, Builder, blockInfo,
1677 entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1678 }
1679 }
1680 // Recover location if it was changed in the above loop.
1681 DI->EmitLocation(Builder,
1682 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1683 }
1684
1685 // And resume where we left off.
1686 if (resume == nullptr)
1687 Builder.ClearInsertionPoint();
1688 else
1689 Builder.SetInsertPoint(resume);
1690
1691 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1692
1693 return fn;
1694}
1695
1696static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1697computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1698 const LangOptions &LangOpts) {
1699 if (CI.getCopyExpr()) {
1700 assert(!CI.isByRef())((!CI.isByRef()) ? static_cast<void> (0) : __assert_fail
("!CI.isByRef()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1700, __PRETTY_FUNCTION__))
;
1701 // don't bother computing flags
1702 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1703 }
1704 BlockFieldFlags Flags;
1705 if (CI.isEscapingByref()) {
1706 Flags = BLOCK_FIELD_IS_BYREF;
1707 if (T.isObjCGCWeak())
1708 Flags |= BLOCK_FIELD_IS_WEAK;
1709 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1710 }
1711
1712 Flags = BLOCK_FIELD_IS_OBJECT;
1713 bool isBlockPointer = T->isBlockPointerType();
1714 if (isBlockPointer)
1715 Flags = BLOCK_FIELD_IS_BLOCK;
1716
1717 switch (T.isNonTrivialToPrimitiveCopy()) {
1718 case QualType::PCK_Struct:
1719 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1720 BlockFieldFlags());
1721 case QualType::PCK_ARCWeak:
1722 // We need to register __weak direct captures with the runtime.
1723 return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1724 case QualType::PCK_ARCStrong:
1725 // We need to retain the copied value for __strong direct captures.
1726 // If it's a block pointer, we have to copy the block and assign that to
1727 // the destination pointer, so we might as well use _Block_object_assign.
1728 // Otherwise we can avoid that.
1729 return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1730 : BlockCaptureEntityKind::BlockObject,
1731 Flags);
1732 case QualType::PCK_Trivial:
1733 case QualType::PCK_VolatileTrivial: {
1734 if (!T->isObjCRetainableType())
1735 // For all other types, the memcpy is fine.
1736 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1737
1738 // Special rules for ARC captures:
1739 Qualifiers QS = T.getQualifiers();
1740
1741 // Non-ARC captures of retainable pointers are strong and
1742 // therefore require a call to _Block_object_assign.
1743 if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1744 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1745
1746 // Otherwise the memcpy is fine.
1747 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1748 }
1749 }
1750 llvm_unreachable("after exhaustive PrimitiveCopyKind switch")::llvm::llvm_unreachable_internal("after exhaustive PrimitiveCopyKind switch"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1750)
;
1751}
1752
1753static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1754computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1755 const LangOptions &LangOpts);
1756
1757/// Find the set of block captures that need to be explicitly copied or destroy.
1758static void findBlockCapturedManagedEntities(
1759 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1760 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1761 for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1762 const VarDecl *Variable = CI.getVariable();
1763 const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1764 if (Capture.isConstant())
1765 continue;
1766
1767 QualType VT = Capture.fieldType();
1768 auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1769 auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1770 if (CopyInfo.first != BlockCaptureEntityKind::None ||
1771 DisposeInfo.first != BlockCaptureEntityKind::None)
1772 ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1773 CopyInfo.second, DisposeInfo.second, CI,
1774 Capture);
1775 }
1776
1777 // Sort the captures by offset.
1778 llvm::sort(ManagedCaptures);
1779}
1780
1781namespace {
1782/// Release a __block variable.
1783struct CallBlockRelease final : EHScopeStack::Cleanup {
1784 Address Addr;
1785 BlockFieldFlags FieldFlags;
1786 bool LoadBlockVarAddr, CanThrow;
1787
1788 CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1789 bool CT)
1790 : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1791 CanThrow(CT) {}
1792
1793 void Emit(CodeGenFunction &CGF, Flags flags) override {
1794 llvm::Value *BlockVarAddr;
1795 if (LoadBlockVarAddr) {
1796 BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1797 BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1798 } else {
1799 BlockVarAddr = Addr.getPointer();
1800 }
1801
1802 CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1803 }
1804};
1805} // end anonymous namespace
1806
1807/// Check if \p T is a C++ class that has a destructor that can throw.
1808bool CodeGenFunction::cxxDestructorCanThrow(QualType T) {
1809 if (const auto *RD = T->getAsCXXRecordDecl())
1810 if (const CXXDestructorDecl *DD = RD->getDestructor())
1811 return DD->getType()->getAs<FunctionProtoType>()->canThrow();
1812 return false;
1813}
1814
1815// Return a string that has the information about a capture.
1816static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1817 CaptureStrKind StrKind,
1818 CharUnits BlockAlignment,
1819 CodeGenModule &CGM) {
1820 std::string Str;
1821 ASTContext &Ctx = CGM.getContext();
1822 const BlockDecl::Capture &CI = *E.CI;
1823 QualType CaptureTy = CI.getVariable()->getType();
1824
1825 BlockCaptureEntityKind Kind;
1826 BlockFieldFlags Flags;
1827
1828 // CaptureStrKind::Merged should be passed only when the operations and the
1829 // flags are the same for copy and dispose.
1830 assert((StrKind != CaptureStrKind::Merged ||(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1832, __PRETTY_FUNCTION__))
1831 (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1832, __PRETTY_FUNCTION__))
1832 "different operations and flags")(((StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind
&& E.CopyFlags == E.DisposeFlags)) && "different operations and flags"
) ? static_cast<void> (0) : __assert_fail ("(StrKind != CaptureStrKind::Merged || (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) && \"different operations and flags\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1832, __PRETTY_FUNCTION__))
;
1833
1834 if (StrKind == CaptureStrKind::DisposeHelper) {
1835 Kind = E.DisposeKind;
1836 Flags = E.DisposeFlags;
1837 } else {
1838 Kind = E.CopyKind;
1839 Flags = E.CopyFlags;
1840 }
1841
1842 switch (Kind) {
1843 case BlockCaptureEntityKind::CXXRecord: {
1844 Str += "c";
1845 SmallString<256> TyStr;
1846 llvm::raw_svector_ostream Out(TyStr);
1847 CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1848 Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1849 break;
1850 }
1851 case BlockCaptureEntityKind::ARCWeak:
1852 Str += "w";
1853 break;
1854 case BlockCaptureEntityKind::ARCStrong:
1855 Str += "s";
1856 break;
1857 case BlockCaptureEntityKind::BlockObject: {
1858 const VarDecl *Var = CI.getVariable();
1859 unsigned F = Flags.getBitMask();
1860 if (F & BLOCK_FIELD_IS_BYREF) {
1861 Str += "r";
1862 if (F & BLOCK_FIELD_IS_WEAK)
1863 Str += "w";
1864 else {
1865 // If CaptureStrKind::Merged is passed, check both the copy expression
1866 // and the destructor.
1867 if (StrKind != CaptureStrKind::DisposeHelper) {
1868 if (Ctx.getBlockVarCopyInit(Var).canThrow())
1869 Str += "c";
1870 }
1871 if (StrKind != CaptureStrKind::CopyHelper) {
1872 if (CodeGenFunction::cxxDestructorCanThrow(CaptureTy))
1873 Str += "d";
1874 }
1875 }
1876 } else {
1877 assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value")(((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value"
) ? static_cast<void> (0) : __assert_fail ("(F & BLOCK_FIELD_IS_OBJECT) && \"unexpected flag value\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1877, __PRETTY_FUNCTION__))
;
1878 if (F == BLOCK_FIELD_IS_BLOCK)
1879 Str += "b";
1880 else
1881 Str += "o";
1882 }
1883 break;
1884 }
1885 case BlockCaptureEntityKind::NonTrivialCStruct: {
1886 bool IsVolatile = CaptureTy.isVolatileQualified();
1887 CharUnits Alignment =
1888 BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1889
1890 Str += "n";
1891 std::string FuncStr;
1892 if (StrKind == CaptureStrKind::DisposeHelper)
1893 FuncStr = CodeGenFunction::getNonTrivialDestructorStr(
1894 CaptureTy, Alignment, IsVolatile, Ctx);
1895 else
1896 // If CaptureStrKind::Merged is passed, use the copy constructor string.
1897 // It has all the information that the destructor string has.
1898 FuncStr = CodeGenFunction::getNonTrivialCopyConstructorStr(
1899 CaptureTy, Alignment, IsVolatile, Ctx);
1900 // The underscore is necessary here because non-trivial copy constructor
1901 // and destructor strings can start with a number.
1902 Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1903 break;
1904 }
1905 case BlockCaptureEntityKind::None:
1906 break;
1907 }
1908
1909 return Str;
1910}
1911
1912static std::string getCopyDestroyHelperFuncName(
1913 const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1914 CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1915 assert((StrKind == CaptureStrKind::CopyHelper ||(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1917, __PRETTY_FUNCTION__))
1916 StrKind == CaptureStrKind::DisposeHelper) &&(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1917, __PRETTY_FUNCTION__))
1917 "unexpected CaptureStrKind")(((StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind
::DisposeHelper) && "unexpected CaptureStrKind") ? static_cast
<void> (0) : __assert_fail ("(StrKind == CaptureStrKind::CopyHelper || StrKind == CaptureStrKind::DisposeHelper) && \"unexpected CaptureStrKind\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 1917, __PRETTY_FUNCTION__))
;
1918 std::string Name = StrKind == CaptureStrKind::CopyHelper
1919 ? "__copy_helper_block_"
1920 : "__destroy_helper_block_";
1921 if (CGM.getLangOpts().Exceptions)
1922 Name += "e";
1923 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1924 Name += "a";
1925 Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1926
1927 for (const BlockCaptureManagedEntity &E : Captures) {
1928 Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1929 Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1930 }
1931
1932 return Name;
1933}
1934
1935static void pushCaptureCleanup(BlockCaptureEntityKind CaptureKind,
1936 Address Field, QualType CaptureType,
1937 BlockFieldFlags Flags, bool ForCopyHelper,
1938 VarDecl *Var, CodeGenFunction &CGF) {
1939 bool EHOnly = ForCopyHelper;
1940
1941 switch (CaptureKind) {
1942 case BlockCaptureEntityKind::CXXRecord:
1943 case BlockCaptureEntityKind::ARCWeak:
1944 case BlockCaptureEntityKind::NonTrivialCStruct:
1945 case BlockCaptureEntityKind::ARCStrong: {
1946 if (CaptureType.isDestructedType() &&
1947 (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1948 CodeGenFunction::Destroyer *Destroyer =
1949 CaptureKind == BlockCaptureEntityKind::ARCStrong
1950 ? CodeGenFunction::destroyARCStrongImprecise
1951 : CGF.getDestroyer(CaptureType.isDestructedType());
1952 CleanupKind Kind =
1953 EHOnly ? EHCleanup
1954 : CGF.getCleanupKind(CaptureType.isDestructedType());
1955 CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1956 }
1957 break;
1958 }
1959 case BlockCaptureEntityKind::BlockObject: {
1960 if (!EHOnly || CGF.getLangOpts().Exceptions) {
1961 CleanupKind Kind = EHOnly ? EHCleanup : NormalAndEHCleanup;
1962 // Calls to _Block_object_dispose along the EH path in the copy helper
1963 // function don't throw as newly-copied __block variables always have a
1964 // reference count of 2.
1965 bool CanThrow =
1966 !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1967 CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1968 CanThrow);
1969 }
1970 break;
1971 }
1972 case BlockCaptureEntityKind::None:
1973 break;
1974 }
1975}
1976
1977static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType,
1978 llvm::Function *Fn,
1979 const CGFunctionInfo &FI,
1980 CodeGenModule &CGM) {
1981 if (CapturesNonExternalType) {
1982 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
1983 } else {
1984 Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1985 Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1986 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1987 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1988 }
1989}
1990/// Generate the copy-helper function for a block closure object:
1991/// static void block_copy_helper(block_t *dst, block_t *src);
1992/// The runtime will have previously initialized 'dst' by doing a
1993/// bit-copy of 'src'.
1994///
1995/// Note that this copies an entire block closure object to the heap;
1996/// it should not be confused with a 'byref copy helper', which moves
1997/// the contents of an individual __block variable to the heap.
1998llvm::Constant *
1999CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
2000 SmallVector<BlockCaptureManagedEntity, 4> CopiedCaptures;
2001 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
2002 std::string FuncName =
2003 getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
2004 CaptureStrKind::CopyHelper, CGM);
2005
2006 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2007 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2008
2009 ASTContext &C = getContext();
2010
2011 QualType ReturnTy = C.VoidTy;
2012
2013 FunctionArgList args;
2014 ImplicitParamDecl DstDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2015 args.push_back(&DstDecl);
2016 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2017 args.push_back(&SrcDecl);
2018
2019 const CGFunctionInfo &FI =
2020 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2021
2022 // FIXME: it would be nice if these were mergeable with things with
2023 // identical semantics.
2024 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2025
2026 llvm::Function *Fn =
2027 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2028 FuncName, &CGM.getModule());
2029
2030 IdentifierInfo *II = &C.Idents.get(FuncName);
2031
2032 SmallVector<QualType, 2> ArgTys;
2033 ArgTys.push_back(C.VoidPtrTy);
2034 ArgTys.push_back(C.VoidPtrTy);
2035 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2036
2037 FunctionDecl *FD = FunctionDecl::Create(
2038 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
2039 FunctionTy, nullptr, SC_Static, false, false);
2040
2041 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2042 CGM);
2043 StartFunction(FD, ReturnTy, Fn, FI, args);
2044 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2045 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2046
2047 Address src = GetAddrOfLocalVar(&SrcDecl);
2048 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2049 src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2050
2051 Address dst = GetAddrOfLocalVar(&DstDecl);
2052 dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2053 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2054
2055 for (const auto &CopiedCapture : CopiedCaptures) {
2056 const BlockDecl::Capture &CI = *CopiedCapture.CI;
2057 const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2058 QualType captureType = CI.getVariable()->getType();
2059 BlockFieldFlags flags = CopiedCapture.CopyFlags;
2060
2061 unsigned index = capture.getIndex();
2062 Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
2063 Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
2064
2065 switch (CopiedCapture.CopyKind) {
2066 case BlockCaptureEntityKind::CXXRecord:
2067 // If there's an explicit copy expression, we do that.
2068 assert(CI.getCopyExpr() && "copy expression for variable is missing")((CI.getCopyExpr() && "copy expression for variable is missing"
) ? static_cast<void> (0) : __assert_fail ("CI.getCopyExpr() && \"copy expression for variable is missing\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2068, __PRETTY_FUNCTION__))
;
2069 EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2070 break;
2071 case BlockCaptureEntityKind::ARCWeak:
2072 EmitARCCopyWeak(dstField, srcField);
2073 break;
2074 case BlockCaptureEntityKind::NonTrivialCStruct: {
2075 // If this is a C struct that requires non-trivial copy construction,
2076 // emit a call to its copy constructor.
2077 QualType varType = CI.getVariable()->getType();
2078 callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2079 MakeAddrLValue(srcField, varType));
2080 break;
2081 }
2082 case BlockCaptureEntityKind::ARCStrong: {
2083 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2084 // At -O0, store null into the destination field (so that the
2085 // storeStrong doesn't over-release) and then call storeStrong.
2086 // This is a workaround to not having an initStrong call.
2087 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2088 auto *ty = cast<llvm::PointerType>(srcValue->getType());
2089 llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2090 Builder.CreateStore(null, dstField);
2091 EmitARCStoreStrongCall(dstField, srcValue, true);
2092
2093 // With optimization enabled, take advantage of the fact that
2094 // the blocks runtime guarantees a memcpy of the block data, and
2095 // just emit a retain of the src field.
2096 } else {
2097 EmitARCRetainNonBlock(srcValue);
2098
2099 // Unless EH cleanup is required, we don't need this anymore, so kill
2100 // it. It's not quite worth the annoyance to avoid creating it in the
2101 // first place.
2102 if (!needsEHCleanup(captureType.isDestructedType()))
2103 cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2104 }
2105 break;
2106 }
2107 case BlockCaptureEntityKind::BlockObject: {
2108 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2109 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2110 llvm::Value *dstAddr =
2111 Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2112 llvm::Value *args[] = {
2113 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2114 };
2115
2116 if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2117 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2118 else
2119 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2120 break;
2121 }
2122 case BlockCaptureEntityKind::None:
2123 continue;
2124 }
2125
2126 // Ensure that we destroy the copied object if an exception is thrown later
2127 // in the helper function.
2128 pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2129 /*ForCopyHelper*/ true, CI.getVariable(), *this);
2130 }
2131
2132 FinishFunction();
2133
2134 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2135}
2136
2137static BlockFieldFlags
2138getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI,
2139 QualType T) {
2140 BlockFieldFlags Flags = BLOCK_FIELD_IS_OBJECT;
2141 if (T->isBlockPointerType())
2142 Flags = BLOCK_FIELD_IS_BLOCK;
2143 return Flags;
2144}
2145
2146static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2147computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
2148 const LangOptions &LangOpts) {
2149 if (CI.isEscapingByref()) {
2150 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2151 if (T.isObjCGCWeak())
2152 Flags |= BLOCK_FIELD_IS_WEAK;
2153 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2154 }
2155
2156 switch (T.isDestructedType()) {
2157 case QualType::DK_cxx_destructor:
2158 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2159 case QualType::DK_objc_strong_lifetime:
2160 // Use objc_storeStrong for __strong direct captures; the
2161 // dynamic tools really like it when we do this.
2162 return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2163 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2164 case QualType::DK_objc_weak_lifetime:
2165 // Support __weak direct captures.
2166 return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2167 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2168 case QualType::DK_nontrivial_c_struct:
2169 return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2170 BlockFieldFlags());
2171 case QualType::DK_none: {
2172 // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2173 if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2174 !LangOpts.ObjCAutoRefCount)
2175 return std::make_pair(BlockCaptureEntityKind::BlockObject,
2176 getBlockFieldFlagsForObjCObjectPointer(CI, T));
2177 // Otherwise, we have nothing to do.
2178 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2179 }
2180 }
2181 llvm_unreachable("after exhaustive DestructionKind switch")::llvm::llvm_unreachable_internal("after exhaustive DestructionKind switch"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2181)
;
2182}
2183
2184/// Generate the destroy-helper function for a block closure object:
2185/// static void block_destroy_helper(block_t *theBlock);
2186///
2187/// Note that this destroys a heap-allocated block closure object;
2188/// it should not be confused with a 'byref destroy helper', which
2189/// destroys the heap-allocated contents of an individual __block
2190/// variable.
2191llvm::Constant *
2192CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
2193 SmallVector<BlockCaptureManagedEntity, 4> DestroyedCaptures;
2194 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2195 std::string FuncName =
2196 getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2197 CaptureStrKind::DisposeHelper, CGM);
2198
2199 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2200 return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2201
2202 ASTContext &C = getContext();
2203
2204 QualType ReturnTy = C.VoidTy;
2205
2206 FunctionArgList args;
2207 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamDecl::Other);
2208 args.push_back(&SrcDecl);
2209
2210 const CGFunctionInfo &FI =
2211 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2212
2213 // FIXME: We'd like to put these into a mergable by content, with
2214 // internal linkage.
2215 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2216
2217 llvm::Function *Fn =
2218 llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2219 FuncName, &CGM.getModule());
2220
2221 IdentifierInfo *II = &C.Idents.get(FuncName);
2222
2223 SmallVector<QualType, 1> ArgTys;
2224 ArgTys.push_back(C.VoidPtrTy);
2225 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2226
2227 FunctionDecl *FD = FunctionDecl::Create(
2228 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
2229 FunctionTy, nullptr, SC_Static, false, false);
2230
2231 setBlockHelperAttributesVisibility(blockInfo.CapturesNonExternalType, Fn, FI,
2232 CGM);
2233 StartFunction(FD, ReturnTy, Fn, FI, args);
2234 markAsIgnoreThreadCheckingAtRuntime(Fn);
2235
2236 ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2237
2238 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2239
2240 Address src = GetAddrOfLocalVar(&SrcDecl);
2241 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2242 src = Builder.CreateBitCast(src, structPtrTy, "block");
2243
2244 CodeGenFunction::RunCleanupsScope cleanups(*this);
2245
2246 for (const auto &DestroyedCapture : DestroyedCaptures) {
2247 const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2248 const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2249 BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2250
2251 Address srcField =
2252 Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
2253
2254 pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2255 CI.getVariable()->getType(), flags,
2256 /*ForCopyHelper*/ false, CI.getVariable(), *this);
2257 }
2258
2259 cleanups.ForceCleanup();
2260
2261 FinishFunction();
2262
2263 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2264}
2265
2266namespace {
2267
2268/// Emits the copy/dispose helper functions for a __block object of id type.
2269class ObjectByrefHelpers final : public BlockByrefHelpers {
2270 BlockFieldFlags Flags;
2271
2272public:
2273 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2274 : BlockByrefHelpers(alignment), Flags(flags) {}
2275
2276 void emitCopy(CodeGenFunction &CGF, Address destField,
2277 Address srcField) override {
2278 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2279
2280 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2281 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2282
2283 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2284
2285 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2286 llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
2287
2288 llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2289 CGF.EmitNounwindRuntimeCall(fn, args);
2290 }
2291
2292 void emitDispose(CodeGenFunction &CGF, Address field) override {
2293 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2294 llvm::Value *value = CGF.Builder.CreateLoad(field);
2295
2296 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2297 }
2298
2299 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2300 id.AddInteger(Flags.getBitMask());
2301 }
2302};
2303
2304/// Emits the copy/dispose helpers for an ARC __block __weak variable.
2305class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2306public:
2307 ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2308
2309 void emitCopy(CodeGenFunction &CGF, Address destField,
2310 Address srcField) override {
2311 CGF.EmitARCMoveWeak(destField, srcField);
2312 }
2313
2314 void emitDispose(CodeGenFunction &CGF, Address field) override {
2315 CGF.EmitARCDestroyWeak(field);
2316 }
2317
2318 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2319 // 0 is distinguishable from all pointers and byref flags
2320 id.AddInteger(0);
2321 }
2322};
2323
2324/// Emits the copy/dispose helpers for an ARC __block __strong variable
2325/// that's not of block-pointer type.
2326class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2327public:
2328 ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2329
2330 void emitCopy(CodeGenFunction &CGF, Address destField,
2331 Address srcField) override {
2332 // Do a "move" by copying the value and then zeroing out the old
2333 // variable.
2334
2335 llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2336
2337 llvm::Value *null =
2338 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2339
2340 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2341 CGF.Builder.CreateStore(null, destField);
2342 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2343 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2344 return;
2345 }
2346 CGF.Builder.CreateStore(value, destField);
2347 CGF.Builder.CreateStore(null, srcField);
2348 }
2349
2350 void emitDispose(CodeGenFunction &CGF, Address field) override {
2351 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2352 }
2353
2354 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2355 // 1 is distinguishable from all pointers and byref flags
2356 id.AddInteger(1);
2357 }
2358};
2359
2360/// Emits the copy/dispose helpers for an ARC __block __strong
2361/// variable that's of block-pointer type.
2362class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2363public:
2364 ARCStrongBlockByrefHelpers(CharUnits alignment)
2365 : BlockByrefHelpers(alignment) {}
2366
2367 void emitCopy(CodeGenFunction &CGF, Address destField,
2368 Address srcField) override {
2369 // Do the copy with objc_retainBlock; that's all that
2370 // _Block_object_assign would do anyway, and we'd have to pass the
2371 // right arguments to make sure it doesn't get no-op'ed.
2372 llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2373 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2374 CGF.Builder.CreateStore(copy, destField);
2375 }
2376
2377 void emitDispose(CodeGenFunction &CGF, Address field) override {
2378 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
2379 }
2380
2381 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2382 // 2 is distinguishable from all pointers and byref flags
2383 id.AddInteger(2);
2384 }
2385};
2386
2387/// Emits the copy/dispose helpers for a __block variable with a
2388/// nontrivial copy constructor or destructor.
2389class CXXByrefHelpers final : public BlockByrefHelpers {
2390 QualType VarType;
2391 const Expr *CopyExpr;
2392
2393public:
2394 CXXByrefHelpers(CharUnits alignment, QualType type,
2395 const Expr *copyExpr)
2396 : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2397
2398 bool needsCopy() const override { return CopyExpr != nullptr; }
2399 void emitCopy(CodeGenFunction &CGF, Address destField,
2400 Address srcField) override {
2401 if (!CopyExpr) return;
2402 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2403 }
2404
2405 void emitDispose(CodeGenFunction &CGF, Address field) override {
2406 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2407 CGF.PushDestructorCleanup(VarType, field);
2408 CGF.PopCleanupBlocks(cleanupDepth);
2409 }
2410
2411 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2412 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2413 }
2414};
2415
2416/// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2417/// C struct.
2418class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2419 QualType VarType;
2420
2421public:
2422 NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2423 : BlockByrefHelpers(alignment), VarType(type) {}
2424
2425 void emitCopy(CodeGenFunction &CGF, Address destField,
2426 Address srcField) override {
2427 CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2428 CGF.MakeAddrLValue(srcField, VarType));
2429 }
2430
2431 bool needsDispose() const override {
2432 return VarType.isDestructedType();
2433 }
2434
2435 void emitDispose(CodeGenFunction &CGF, Address field) override {
2436 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2437 CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2438 CGF.PopCleanupBlocks(cleanupDepth);
2439 }
2440
2441 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2442 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2443 }
2444};
2445} // end anonymous namespace
2446
2447static llvm::Constant *
2448generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo,
2449 BlockByrefHelpers &generator) {
2450 ASTContext &Context = CGF.getContext();
2451
2452 QualType ReturnTy = Context.VoidTy;
2453
2454 FunctionArgList args;
2455 ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2456 args.push_back(&Dst);
2457
2458 ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2459 args.push_back(&Src);
2460
2461 const CGFunctionInfo &FI =
2462 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2463
2464 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2465
2466 // FIXME: We'd like to put these into a mergable by content, with
2467 // internal linkage.
2468 llvm::Function *Fn =
2469 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2470 "__Block_byref_object_copy_", &CGF.CGM.getModule());
2471
2472 IdentifierInfo *II
2473 = &Context.Idents.get("__Block_byref_object_copy_");
2474
2475 SmallVector<QualType, 2> ArgTys;
2476 ArgTys.push_back(Context.VoidPtrTy);
2477 ArgTys.push_back(Context.VoidPtrTy);
2478 QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2479
2480 FunctionDecl *FD = FunctionDecl::Create(
2481 Context, Context.getTranslationUnitDecl(), SourceLocation(),
2482 SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2483
2484 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2485
2486 CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2487
2488 if (generator.needsCopy()) {
2489 llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2490
2491 // dst->x
2492 Address destField = CGF.GetAddrOfLocalVar(&Dst);
2493 destField = Address(CGF.Builder.CreateLoad(destField),
2494 byrefInfo.ByrefAlignment);
2495 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2496 destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2497 "dest-object");
2498
2499 // src->x
2500 Address srcField = CGF.GetAddrOfLocalVar(&Src);
2501 srcField = Address(CGF.Builder.CreateLoad(srcField),
2502 byrefInfo.ByrefAlignment);
2503 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2504 srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2505 "src-object");
2506
2507 generator.emitCopy(CGF, destField, srcField);
2508 }
2509
2510 CGF.FinishFunction();
2511
2512 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2513}
2514
2515/// Build the copy helper for a __block variable.
2516static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2517 const BlockByrefInfo &byrefInfo,
2518 BlockByrefHelpers &generator) {
2519 CodeGenFunction CGF(CGM);
2520 return generateByrefCopyHelper(CGF, byrefInfo, generator);
2521}
2522
2523/// Generate code for a __block variable's dispose helper.
2524static llvm::Constant *
2525generateByrefDisposeHelper(CodeGenFunction &CGF,
2526 const BlockByrefInfo &byrefInfo,
2527 BlockByrefHelpers &generator) {
2528 ASTContext &Context = CGF.getContext();
2529 QualType R = Context.VoidTy;
2530
2531 FunctionArgList args;
2532 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2533 ImplicitParamDecl::Other);
2534 args.push_back(&Src);
2535
2536 const CGFunctionInfo &FI =
2537 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
2538
2539 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2540
2541 // FIXME: We'd like to put these into a mergable by content, with
2542 // internal linkage.
2543 llvm::Function *Fn =
2544 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2545 "__Block_byref_object_dispose_",
2546 &CGF.CGM.getModule());
2547
2548 IdentifierInfo *II
2549 = &Context.Idents.get("__Block_byref_object_dispose_");
2550
2551 SmallVector<QualType, 1> ArgTys;
2552 ArgTys.push_back(Context.VoidPtrTy);
2553 QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2554
2555 FunctionDecl *FD = FunctionDecl::Create(
2556 Context, Context.getTranslationUnitDecl(), SourceLocation(),
2557 SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2558
2559 CGF.CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
2560
2561 CGF.StartFunction(FD, R, Fn, FI, args);
2562
2563 if (generator.needsDispose()) {
2564 Address addr = CGF.GetAddrOfLocalVar(&Src);
2565 addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2566 auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2567 addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2568 addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2569
2570 generator.emitDispose(CGF, addr);
2571 }
2572
2573 CGF.FinishFunction();
2574
2575 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2576}
2577
2578/// Build the dispose helper for a __block variable.
2579static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2580 const BlockByrefInfo &byrefInfo,
2581 BlockByrefHelpers &generator) {
2582 CodeGenFunction CGF(CGM);
2583 return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2584}
2585
2586/// Lazily build the copy and dispose helpers for a __block variable
2587/// with the given information.
2588template <class T>
2589static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2590 T &&generator) {
2591 llvm::FoldingSetNodeID id;
2592 generator.Profile(id);
2593
2594 void *insertPos;
2595 BlockByrefHelpers *node
2596 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2597 if (node) return static_cast<T*>(node);
2598
2599 generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2600 generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2601
2602 T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2603 CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2604 return copy;
2605}
2606
2607/// Build the copy and dispose helpers for the given __block variable
2608/// emission. Places the helpers in the global cache. Returns null
2609/// if no helpers are required.
2610BlockByrefHelpers *
2611CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2612 const AutoVarEmission &emission) {
2613 const VarDecl &var = *emission.Variable;
2614 assert(var.isEscapingByref() &&((var.isEscapingByref() && "only escaping __block variables need byref helpers"
) ? static_cast<void> (0) : __assert_fail ("var.isEscapingByref() && \"only escaping __block variables need byref helpers\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2615, __PRETTY_FUNCTION__))
2615 "only escaping __block variables need byref helpers")((var.isEscapingByref() && "only escaping __block variables need byref helpers"
) ? static_cast<void> (0) : __assert_fail ("var.isEscapingByref() && \"only escaping __block variables need byref helpers\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2615, __PRETTY_FUNCTION__))
;
2616
2617 QualType type = var.getType();
2618
2619 auto &byrefInfo = getBlockByrefInfo(&var);
2620
2621 // The alignment we care about for the purposes of uniquing byref
2622 // helpers is the alignment of the actual byref value field.
2623 CharUnits valueAlignment =
2624 byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2625
2626 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2627 const Expr *copyExpr =
2628 CGM.getContext().getBlockVarCopyInit(&var).getCopyExpr();
2629 if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2630
2631 return ::buildByrefHelpers(
2632 CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2633 }
2634
2635 // If type is a non-trivial C struct type that is non-trivial to
2636 // destructly move or destroy, build the copy and dispose helpers.
2637 if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2638 type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2639 return ::buildByrefHelpers(
2640 CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2641
2642 // Otherwise, if we don't have a retainable type, there's nothing to do.
2643 // that the runtime does extra copies.
2644 if (!type->isObjCRetainableType()) return nullptr;
2645
2646 Qualifiers qs = type.getQualifiers();
2647
2648 // If we have lifetime, that dominates.
2649 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2650 switch (lifetime) {
2651 case Qualifiers::OCL_None: llvm_unreachable("impossible")::llvm::llvm_unreachable_internal("impossible", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2651)
;
2652
2653 // These are just bits as far as the runtime is concerned.
2654 case Qualifiers::OCL_ExplicitNone:
2655 case Qualifiers::OCL_Autoreleasing:
2656 return nullptr;
2657
2658 // Tell the runtime that this is ARC __weak, called by the
2659 // byref routines.
2660 case Qualifiers::OCL_Weak:
2661 return ::buildByrefHelpers(CGM, byrefInfo,
2662 ARCWeakByrefHelpers(valueAlignment));
2663
2664 // ARC __strong __block variables need to be retained.
2665 case Qualifiers::OCL_Strong:
2666 // Block pointers need to be copied, and there's no direct
2667 // transfer possible.
2668 if (type->isBlockPointerType()) {
2669 return ::buildByrefHelpers(CGM, byrefInfo,
2670 ARCStrongBlockByrefHelpers(valueAlignment));
2671
2672 // Otherwise, we transfer ownership of the retain from the stack
2673 // to the heap.
2674 } else {
2675 return ::buildByrefHelpers(CGM, byrefInfo,
2676 ARCStrongByrefHelpers(valueAlignment));
2677 }
2678 }
2679 llvm_unreachable("fell out of lifetime switch!")::llvm::llvm_unreachable_internal("fell out of lifetime switch!"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2679)
;
2680 }
2681
2682 BlockFieldFlags flags;
2683 if (type->isBlockPointerType()) {
2684 flags |= BLOCK_FIELD_IS_BLOCK;
2685 } else if (CGM.getContext().isObjCNSObjectType(type) ||
2686 type->isObjCObjectPointerType()) {
2687 flags |= BLOCK_FIELD_IS_OBJECT;
2688 } else {
2689 return nullptr;
2690 }
2691
2692 if (type.isObjCGCWeak())
2693 flags |= BLOCK_FIELD_IS_WEAK;
2694
2695 return ::buildByrefHelpers(CGM, byrefInfo,
2696 ObjectByrefHelpers(valueAlignment, flags));
2697}
2698
2699Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2700 const VarDecl *var,
2701 bool followForward) {
2702 auto &info = getBlockByrefInfo(var);
2703 return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2704}
2705
2706Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2707 const BlockByrefInfo &info,
2708 bool followForward,
2709 const llvm::Twine &name) {
2710 // Chase the forwarding address if requested.
2711 if (followForward) {
2712 Address forwardingAddr =
2713 Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2714 baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2715 }
2716
2717 return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2718 info.FieldOffset, name);
2719}
2720
2721/// BuildByrefInfo - This routine changes a __block variable declared as T x
2722/// into:
2723///
2724/// struct {
2725/// void *__isa;
2726/// void *__forwarding;
2727/// int32_t __flags;
2728/// int32_t __size;
2729/// void *__copy_helper; // only if needed
2730/// void *__destroy_helper; // only if needed
2731/// void *__byref_variable_layout;// only if needed
2732/// char padding[X]; // only if needed
2733/// T x;
2734/// } x
2735///
2736const BlockByrefInfo &CodeGenFunction::getBlockByrefInfo(const VarDecl *D) {
2737 auto it = BlockByrefInfos.find(D);
2738 if (it != BlockByrefInfos.end())
2739 return it->second;
2740
2741 llvm::StructType *byrefType =
2742 llvm::StructType::create(getLLVMContext(),
2743 "struct.__block_byref_" + D->getNameAsString());
2744
2745 QualType Ty = D->getType();
2746
2747 CharUnits size;
2748 SmallVector<llvm::Type *, 8> types;
2749
2750 // void *__isa;
2751 types.push_back(Int8PtrTy);
2752 size += getPointerSize();
2753
2754 // void *__forwarding;
2755 types.push_back(llvm::PointerType::getUnqual(byrefType));
2756 size += getPointerSize();
2757
2758 // int32_t __flags;
2759 types.push_back(Int32Ty);
2760 size += CharUnits::fromQuantity(4);
2761
2762 // int32_t __size;
2763 types.push_back(Int32Ty);
2764 size += CharUnits::fromQuantity(4);
2765
2766 // Note that this must match *exactly* the logic in buildByrefHelpers.
2767 bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2768 if (hasCopyAndDispose) {
2769 /// void *__copy_helper;
2770 types.push_back(Int8PtrTy);
2771 size += getPointerSize();
2772
2773 /// void *__destroy_helper;
2774 types.push_back(Int8PtrTy);
2775 size += getPointerSize();
2776 }
2777
2778 bool HasByrefExtendedLayout = false;
2779 Qualifiers::ObjCLifetime Lifetime;
2780 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2781 HasByrefExtendedLayout) {
2782 /// void *__byref_variable_layout;
2783 types.push_back(Int8PtrTy);
2784 size += CharUnits::fromQuantity(PointerSizeInBytes);
2785 }
2786
2787 // T x;
2788 llvm::Type *varTy = ConvertTypeForMem(Ty);
2789
2790 bool packed = false;
2791 CharUnits varAlign = getContext().getDeclAlign(D);
2792 CharUnits varOffset = size.alignTo(varAlign);
2793
2794 // We may have to insert padding.
2795 if (varOffset != size) {
2796 llvm::Type *paddingTy =
2797 llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2798
2799 types.push_back(paddingTy);
2800 size = varOffset;
2801
2802 // Conversely, we might have to prevent LLVM from inserting padding.
2803 } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2804 > varAlign.getQuantity()) {
2805 packed = true;
2806 }
2807 types.push_back(varTy);
2808
2809 byrefType->setBody(types, packed);
2810
2811 BlockByrefInfo info;
2812 info.Type = byrefType;
2813 info.FieldIndex = types.size() - 1;
2814 info.FieldOffset = varOffset;
2815 info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2816
2817 auto pair = BlockByrefInfos.insert({D, info});
2818 assert(pair.second && "info was inserted recursively?")((pair.second && "info was inserted recursively?") ? static_cast
<void> (0) : __assert_fail ("pair.second && \"info was inserted recursively?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2818, __PRETTY_FUNCTION__))
;
2819 return pair.first->second;
2820}
2821
2822/// Initialize the structural components of a __block variable, i.e.
2823/// everything but the actual object.
2824void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) {
2825 // Find the address of the local.
2826 Address addr = emission.Addr;
2827
2828 // That's an alloca of the byref structure type.
2829 llvm::StructType *byrefType = cast<llvm::StructType>(
2830 cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2831
2832 unsigned nextHeaderIndex = 0;
2833 CharUnits nextHeaderOffset;
2834 auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2835 const Twine &name) {
2836 auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2837 nextHeaderOffset, name);
2838 Builder.CreateStore(value, fieldAddr);
2839
2840 nextHeaderIndex++;
2841 nextHeaderOffset += fieldSize;
2842 };
2843
2844 // Build the byref helpers if necessary. This is null if we don't need any.
2845 BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2846
2847 const VarDecl &D = *emission.Variable;
2848 QualType type = D.getType();
2849
2850 bool HasByrefExtendedLayout;
2851 Qualifiers::ObjCLifetime ByrefLifetime;
2852 bool ByRefHasLifetime =
2853 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2854
2855 llvm::Value *V;
2856
2857 // Initialize the 'isa', which is just 0 or 1.
2858 int isa = 0;
2859 if (type.isObjCGCWeak())
2860 isa = 1;
2861 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2862 storeHeaderField(V, getPointerSize(), "byref.isa");
2863
2864 // Store the address of the variable into its own forwarding pointer.
2865 storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2866
2867 // Blocks ABI:
2868 // c) the flags field is set to either 0 if no helper functions are
2869 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2870 BlockFlags flags;
2871 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2872 if (ByRefHasLifetime) {
2873 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2874 else switch (ByrefLifetime) {
2875 case Qualifiers::OCL_Strong:
2876 flags |= BLOCK_BYREF_LAYOUT_STRONG;
2877 break;
2878 case Qualifiers::OCL_Weak:
2879 flags |= BLOCK_BYREF_LAYOUT_WEAK;
2880 break;
2881 case Qualifiers::OCL_ExplicitNone:
2882 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED;
2883 break;
2884 case Qualifiers::OCL_None:
2885 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2886 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT;
2887 break;
2888 default:
2889 break;
2890 }
2891 if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2892 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2893 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2894 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2895 if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2896 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2897 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2898 printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2899 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2900 printf(" BLOCK_BYREF_LAYOUT_STRONG");
2901 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2902 printf(" BLOCK_BYREF_LAYOUT_WEAK");
2903 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2904 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2905 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2906 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2907 }
2908 printf("\n");
2909 }
2910 }
2911 storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2912 getIntSize(), "byref.flags");
2913
2914 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2915 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2916 storeHeaderField(V, getIntSize(), "byref.size");
2917
2918 if (helpers) {
2919 storeHeaderField(helpers->CopyHelper, getPointerSize(),
2920 "byref.copyHelper");
2921 storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2922 "byref.disposeHelper");
2923 }
2924
2925 if (ByRefHasLifetime && HasByrefExtendedLayout) {
2926 auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2927 storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2928 }
2929}
2930
2931void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags,
2932 bool CanThrow) {
2933 llvm::Value *F = CGM.getBlockObjectDispose();
2934 llvm::Value *args[] = {
2935 Builder.CreateBitCast(V, Int8PtrTy),
2936 llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2937 };
2938
2939 if (CanThrow)
2940 EmitRuntimeCallOrInvoke(F, args);
2941 else
2942 EmitNounwindRuntimeCall(F, args);
2943}
2944
2945void CodeGenFunction::enterByrefCleanup(CleanupKind Kind, Address Addr,
2946 BlockFieldFlags Flags,
2947 bool LoadBlockVarAddr, bool CanThrow) {
2948 EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2949 CanThrow);
2950}
2951
2952/// Adjust the declaration of something from the blocks API.
2953static void configureBlocksRuntimeObject(CodeGenModule &CGM,
2954 llvm::Constant *C) {
2955 auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2956
2957 if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2958 IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2959 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2960 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2961
2962 assert((isa<llvm::Function>(C->stripPointerCasts()) ||(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2964, __PRETTY_FUNCTION__))
2963 isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2964, __PRETTY_FUNCTION__))
2964 "expected Function or GlobalVariable")(((isa<llvm::Function>(C->stripPointerCasts()) || isa
<llvm::GlobalVariable>(C->stripPointerCasts())) &&
"expected Function or GlobalVariable") ? static_cast<void
> (0) : __assert_fail ("(isa<llvm::Function>(C->stripPointerCasts()) || isa<llvm::GlobalVariable>(C->stripPointerCasts())) && \"expected Function or GlobalVariable\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGBlocks.cpp"
, 2964, __PRETTY_FUNCTION__))
;
2965
2966 const NamedDecl *ND = nullptr;
2967 for (const auto &Result : DC->lookup(&II))
2968 if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2969 (ND = dyn_cast<VarDecl>(Result)))
2970 break;
2971
2972 // TODO: support static blocks runtime
2973 if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2974 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2975 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2976 } else {
2977 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2978 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2979 }
2980 }
2981
2982 if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2983 GV->hasExternalLinkage())
2984 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2985
2986 CGM.setDSOLocal(GV);
2987}
2988
2989llvm::Constant *CodeGenModule::getBlockObjectDispose() {
2990 if (BlockObjectDispose)
2991 return BlockObjectDispose;
2992
2993 llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2994 llvm::FunctionType *fty
2995 = llvm::FunctionType::get(VoidTy, args, false);
2996 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2997 configureBlocksRuntimeObject(*this, BlockObjectDispose);
2998 return BlockObjectDispose;
2999}
3000
3001llvm::Constant *CodeGenModule::getBlockObjectAssign() {
3002 if (BlockObjectAssign)
3003 return BlockObjectAssign;
3004
3005 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
3006 llvm::FunctionType *fty
3007 = llvm::FunctionType::get(VoidTy, args, false);
3008 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3009 configureBlocksRuntimeObject(*this, BlockObjectAssign);
3010 return BlockObjectAssign;
3011}
3012
3013llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
3014 if (NSConcreteGlobalBlock)
3015 return NSConcreteGlobalBlock;
3016
3017 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3018 Int8PtrTy->getPointerTo(),
3019 nullptr);
3020 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3021 return NSConcreteGlobalBlock;
3022}
3023
3024llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
3025 if (NSConcreteStackBlock)
3026 return NSConcreteStackBlock;
3027
3028 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3029 Int8PtrTy->getPointerTo(),
3030 nullptr);
3031 configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3032 return NSConcreteStackBlock;
3033}