xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CGNonTrivialStruct.cpp (revision 68d75eff68281c1b445e3010bb975eae07aac225)
1 //===--- CGNonTrivialStruct.cpp - Emit Special Functions for C Structs ----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines functions to generate various special functions for C
10 // structs.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CodeGenModule.h"
16 #include "clang/AST/NonTrivialTypeVisitor.h"
17 #include "clang/CodeGen/CodeGenABITypes.h"
18 #include "llvm/Support/ScopedPrinter.h"
19 #include <array>
20 
21 using namespace clang;
22 using namespace CodeGen;
23 
24 // Return the size of a field in number of bits.
25 static uint64_t getFieldSize(const FieldDecl *FD, QualType FT,
26                              ASTContext &Ctx) {
27   if (FD && FD->isBitField())
28     return FD->getBitWidthValue(Ctx);
29   return Ctx.getTypeSize(FT);
30 }
31 
32 namespace {
33 enum { DstIdx = 0, SrcIdx = 1 };
34 const char *ValNameStr[2] = {"dst", "src"};
35 
36 template <class Derived> struct StructVisitor {
37   StructVisitor(ASTContext &Ctx) : Ctx(Ctx) {}
38 
39   template <class... Ts>
40   void visitStructFields(QualType QT, CharUnits CurStructOffset, Ts... Args) {
41     const RecordDecl *RD = QT->castAs<RecordType>()->getDecl();
42 
43     // Iterate over the fields of the struct.
44     for (const FieldDecl *FD : RD->fields()) {
45       QualType FT = FD->getType();
46       FT = QT.isVolatileQualified() ? FT.withVolatile() : FT;
47       asDerived().visit(FT, FD, CurStructOffset, Args...);
48     }
49 
50     asDerived().flushTrivialFields(Args...);
51   }
52 
53   template <class... Ts> void visitTrivial(Ts... Args) {}
54 
55   template <class... Ts> void visitCXXDestructor(Ts... Args) {
56     llvm_unreachable("field of a C++ struct type is not expected");
57   }
58 
59   template <class... Ts> void flushTrivialFields(Ts... Args) {}
60 
61   uint64_t getFieldOffsetInBits(const FieldDecl *FD) {
62     return FD ? Ctx.getASTRecordLayout(FD->getParent())
63                     .getFieldOffset(FD->getFieldIndex())
64               : 0;
65   }
66 
67   CharUnits getFieldOffset(const FieldDecl *FD) {
68     return Ctx.toCharUnitsFromBits(getFieldOffsetInBits(FD));
69   }
70 
71   Derived &asDerived() { return static_cast<Derived &>(*this); }
72 
73   ASTContext &getContext() { return Ctx; }
74   ASTContext &Ctx;
75 };
76 
77 template <class Derived, bool IsMove>
78 struct CopyStructVisitor : StructVisitor<Derived>,
79                            CopiedTypeVisitor<Derived, IsMove> {
80   using StructVisitor<Derived>::asDerived;
81   using Super = CopiedTypeVisitor<Derived, IsMove>;
82 
83   CopyStructVisitor(ASTContext &Ctx) : StructVisitor<Derived>(Ctx) {}
84 
85   template <class... Ts>
86   void preVisit(QualType::PrimitiveCopyKind PCK, QualType FT,
87                 const FieldDecl *FD, CharUnits CurStructOffset, Ts &&... Args) {
88     if (PCK)
89       asDerived().flushTrivialFields(std::forward<Ts>(Args)...);
90   }
91 
92   template <class... Ts>
93   void visitWithKind(QualType::PrimitiveCopyKind PCK, QualType FT,
94                      const FieldDecl *FD, CharUnits CurStructOffset,
95                      Ts &&... Args) {
96     if (const auto *AT = asDerived().getContext().getAsArrayType(FT)) {
97       asDerived().visitArray(PCK, AT, FT.isVolatileQualified(), FD,
98                              CurStructOffset, std::forward<Ts>(Args)...);
99       return;
100     }
101 
102     Super::visitWithKind(PCK, FT, FD, CurStructOffset,
103                          std::forward<Ts>(Args)...);
104   }
105 
106   template <class... Ts>
107   void visitTrivial(QualType FT, const FieldDecl *FD, CharUnits CurStructOffset,
108                     Ts... Args) {
109     assert(!FT.isVolatileQualified() && "volatile field not expected");
110     ASTContext &Ctx = asDerived().getContext();
111     uint64_t FieldSize = getFieldSize(FD, FT, Ctx);
112 
113     // Ignore zero-sized fields.
114     if (FieldSize == 0)
115       return;
116 
117     uint64_t FStartInBits = asDerived().getFieldOffsetInBits(FD);
118     uint64_t FEndInBits = FStartInBits + FieldSize;
119     uint64_t RoundedFEnd = llvm::alignTo(FEndInBits, Ctx.getCharWidth());
120 
121     // Set Start if this is the first field of a sequence of trivial fields.
122     if (Start == End)
123       Start = CurStructOffset + Ctx.toCharUnitsFromBits(FStartInBits);
124     End = CurStructOffset + Ctx.toCharUnitsFromBits(RoundedFEnd);
125   }
126 
127   CharUnits Start = CharUnits::Zero(), End = CharUnits::Zero();
128 };
129 
130 // This function creates the mangled name of a special function of a non-trivial
131 // C struct. Since there is no ODR in C, the function is mangled based on the
132 // struct contents and not the name. The mangled name has the following
133 // structure:
134 //
135 // <function-name> ::= <prefix> <alignment-info> "_" <struct-field-info>
136 // <prefix> ::= "__destructor_" | "__default_constructor_" |
137 //              "__copy_constructor_" | "__move_constructor_" |
138 //              "__copy_assignment_" | "__move_assignment_"
139 // <alignment-info> ::= <dst-alignment> ["_" <src-alignment>]
140 // <struct-field-info> ::= <field-info>+
141 // <field-info> ::= <struct-or-scalar-field-info> | <array-field-info>
142 // <struct-or-scalar-field-info> ::= "_S" <struct-field-info> |
143 //                                   <strong-field-info> | <trivial-field-info>
144 // <array-field-info> ::= "_AB" <array-offset> "s" <element-size> "n"
145 //                        <num-elements> <innermost-element-info> "_AE"
146 // <innermost-element-info> ::= <struct-or-scalar-field-info>
147 // <strong-field-info> ::= "_s" ["b"] ["v"] <field-offset>
148 // <trivial-field-info> ::= "_t" ["v"] <field-offset> "_" <field-size>
149 
150 template <class Derived> struct GenFuncNameBase {
151   std::string getVolatileOffsetStr(bool IsVolatile, CharUnits Offset) {
152     std::string S;
153     if (IsVolatile)
154       S = "v";
155     S += llvm::to_string(Offset.getQuantity());
156     return S;
157   }
158 
159   void visitARCStrong(QualType FT, const FieldDecl *FD,
160                       CharUnits CurStructOffset) {
161     appendStr("_s");
162     if (FT->isBlockPointerType())
163       appendStr("b");
164     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
165     appendStr(getVolatileOffsetStr(FT.isVolatileQualified(), FieldOffset));
166   }
167 
168   void visitARCWeak(QualType FT, const FieldDecl *FD,
169                     CharUnits CurStructOffset) {
170     appendStr("_w");
171     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
172     appendStr(getVolatileOffsetStr(FT.isVolatileQualified(), FieldOffset));
173   }
174 
175   void visitStruct(QualType QT, const FieldDecl *FD,
176                    CharUnits CurStructOffset) {
177     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
178     appendStr("_S");
179     asDerived().visitStructFields(QT, FieldOffset);
180   }
181 
182   template <class FieldKind>
183   void visitArray(FieldKind FK, const ArrayType *AT, bool IsVolatile,
184                   const FieldDecl *FD, CharUnits CurStructOffset) {
185     // String for non-volatile trivial fields is emitted when
186     // flushTrivialFields is called.
187     if (!FK)
188       return asDerived().visitTrivial(QualType(AT, 0), FD, CurStructOffset);
189 
190     asDerived().flushTrivialFields();
191     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
192     ASTContext &Ctx = asDerived().getContext();
193     const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
194     unsigned NumElts = Ctx.getConstantArrayElementCount(CAT);
195     QualType EltTy = Ctx.getBaseElementType(CAT);
196     CharUnits EltSize = Ctx.getTypeSizeInChars(EltTy);
197     appendStr("_AB" + llvm::to_string(FieldOffset.getQuantity()) + "s" +
198               llvm::to_string(EltSize.getQuantity()) + "n" +
199               llvm::to_string(NumElts));
200     EltTy = IsVolatile ? EltTy.withVolatile() : EltTy;
201     asDerived().visitWithKind(FK, EltTy, nullptr, FieldOffset);
202     appendStr("_AE");
203   }
204 
205   void appendStr(StringRef Str) { Name += Str; }
206 
207   std::string getName(QualType QT, bool IsVolatile) {
208     QT = IsVolatile ? QT.withVolatile() : QT;
209     asDerived().visitStructFields(QT, CharUnits::Zero());
210     return Name;
211   }
212 
213   Derived &asDerived() { return static_cast<Derived &>(*this); }
214 
215   std::string Name;
216 };
217 
218 template <class Derived>
219 struct GenUnaryFuncName : StructVisitor<Derived>, GenFuncNameBase<Derived> {
220   GenUnaryFuncName(StringRef Prefix, CharUnits DstAlignment, ASTContext &Ctx)
221       : StructVisitor<Derived>(Ctx) {
222     this->appendStr(Prefix);
223     this->appendStr(llvm::to_string(DstAlignment.getQuantity()));
224   }
225 };
226 
227 // Helper function to create a null constant.
228 static llvm::Constant *getNullForVariable(Address Addr) {
229   llvm::Type *Ty = Addr.getElementType();
230   return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(Ty));
231 }
232 
233 template <bool IsMove>
234 struct GenBinaryFuncName : CopyStructVisitor<GenBinaryFuncName<IsMove>, IsMove>,
235                            GenFuncNameBase<GenBinaryFuncName<IsMove>> {
236 
237   GenBinaryFuncName(StringRef Prefix, CharUnits DstAlignment,
238                     CharUnits SrcAlignment, ASTContext &Ctx)
239       : CopyStructVisitor<GenBinaryFuncName<IsMove>, IsMove>(Ctx) {
240     this->appendStr(Prefix);
241     this->appendStr(llvm::to_string(DstAlignment.getQuantity()));
242     this->appendStr("_" + llvm::to_string(SrcAlignment.getQuantity()));
243   }
244 
245   void flushTrivialFields() {
246     if (this->Start == this->End)
247       return;
248 
249     this->appendStr("_t" + llvm::to_string(this->Start.getQuantity()) + "w" +
250                     llvm::to_string((this->End - this->Start).getQuantity()));
251 
252     this->Start = this->End = CharUnits::Zero();
253   }
254 
255   void visitVolatileTrivial(QualType FT, const FieldDecl *FD,
256                             CharUnits CurStructOffset) {
257     // Because volatile fields can be bit-fields and are individually copied,
258     // their offset and width are in bits.
259     uint64_t OffsetInBits =
260         this->Ctx.toBits(CurStructOffset) + this->getFieldOffsetInBits(FD);
261     this->appendStr("_tv" + llvm::to_string(OffsetInBits) + "w" +
262                     llvm::to_string(getFieldSize(FD, FT, this->Ctx)));
263   }
264 };
265 
266 struct GenDefaultInitializeFuncName
267     : GenUnaryFuncName<GenDefaultInitializeFuncName>,
268       DefaultInitializedTypeVisitor<GenDefaultInitializeFuncName> {
269   using Super = DefaultInitializedTypeVisitor<GenDefaultInitializeFuncName>;
270   GenDefaultInitializeFuncName(CharUnits DstAlignment, ASTContext &Ctx)
271       : GenUnaryFuncName<GenDefaultInitializeFuncName>("__default_constructor_",
272                                                        DstAlignment, Ctx) {}
273   void visitWithKind(QualType::PrimitiveDefaultInitializeKind PDIK, QualType FT,
274                      const FieldDecl *FD, CharUnits CurStructOffset) {
275     if (const auto *AT = getContext().getAsArrayType(FT)) {
276       visitArray(PDIK, AT, FT.isVolatileQualified(), FD, CurStructOffset);
277       return;
278     }
279 
280     Super::visitWithKind(PDIK, FT, FD, CurStructOffset);
281   }
282 };
283 
284 struct GenDestructorFuncName : GenUnaryFuncName<GenDestructorFuncName>,
285                                DestructedTypeVisitor<GenDestructorFuncName> {
286   using Super = DestructedTypeVisitor<GenDestructorFuncName>;
287   GenDestructorFuncName(const char *Prefix, CharUnits DstAlignment,
288                         ASTContext &Ctx)
289       : GenUnaryFuncName<GenDestructorFuncName>(Prefix, DstAlignment, Ctx) {}
290   void visitWithKind(QualType::DestructionKind DK, QualType FT,
291                      const FieldDecl *FD, CharUnits CurStructOffset) {
292     if (const auto *AT = getContext().getAsArrayType(FT)) {
293       visitArray(DK, AT, FT.isVolatileQualified(), FD, CurStructOffset);
294       return;
295     }
296 
297     Super::visitWithKind(DK, FT, FD, CurStructOffset);
298   }
299 };
300 
301 // Helper function that creates CGFunctionInfo for an N-ary special function.
302 template <size_t N>
303 static const CGFunctionInfo &getFunctionInfo(CodeGenModule &CGM,
304                                              FunctionArgList &Args) {
305   ASTContext &Ctx = CGM.getContext();
306   llvm::SmallVector<ImplicitParamDecl *, N> Params;
307   QualType ParamTy = Ctx.getPointerType(Ctx.VoidPtrTy);
308 
309   for (unsigned I = 0; I < N; ++I)
310     Params.push_back(ImplicitParamDecl::Create(
311         Ctx, nullptr, SourceLocation(), &Ctx.Idents.get(ValNameStr[I]), ParamTy,
312         ImplicitParamDecl::Other));
313 
314   for (auto &P : Params)
315     Args.push_back(P);
316 
317   return CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, Args);
318 }
319 
320 // Template classes that are used as bases for classes that emit special
321 // functions.
322 template <class Derived> struct GenFuncBase {
323   template <size_t N>
324   void visitStruct(QualType FT, const FieldDecl *FD, CharUnits CurStructOffset,
325                    std::array<Address, N> Addrs) {
326     this->asDerived().callSpecialFunction(
327         FT, CurStructOffset + asDerived().getFieldOffset(FD), Addrs);
328   }
329 
330   template <class FieldKind, size_t N>
331   void visitArray(FieldKind FK, const ArrayType *AT, bool IsVolatile,
332                   const FieldDecl *FD, CharUnits CurStructOffset,
333                   std::array<Address, N> Addrs) {
334     // Non-volatile trivial fields are copied when flushTrivialFields is called.
335     if (!FK)
336       return asDerived().visitTrivial(QualType(AT, 0), FD, CurStructOffset,
337                                       Addrs);
338 
339     asDerived().flushTrivialFields(Addrs);
340     CodeGenFunction &CGF = *this->CGF;
341     ASTContext &Ctx = CGF.getContext();
342 
343     // Compute the end address.
344     QualType BaseEltQT;
345     std::array<Address, N> StartAddrs = Addrs;
346     for (unsigned I = 0; I < N; ++I)
347       StartAddrs[I] = getAddrWithOffset(Addrs[I], CurStructOffset, FD);
348     Address DstAddr = StartAddrs[DstIdx];
349     llvm::Value *NumElts = CGF.emitArrayLength(AT, BaseEltQT, DstAddr);
350     unsigned BaseEltSize = Ctx.getTypeSizeInChars(BaseEltQT).getQuantity();
351     llvm::Value *BaseEltSizeVal =
352         llvm::ConstantInt::get(NumElts->getType(), BaseEltSize);
353     llvm::Value *SizeInBytes =
354         CGF.Builder.CreateNUWMul(BaseEltSizeVal, NumElts);
355     Address BC = CGF.Builder.CreateBitCast(DstAddr, CGF.CGM.Int8PtrTy);
356     llvm::Value *DstArrayEnd =
357         CGF.Builder.CreateInBoundsGEP(BC.getPointer(), SizeInBytes);
358     DstArrayEnd = CGF.Builder.CreateBitCast(DstArrayEnd, CGF.CGM.Int8PtrPtrTy,
359                                             "dstarray.end");
360     llvm::BasicBlock *PreheaderBB = CGF.Builder.GetInsertBlock();
361 
362     // Create the header block and insert the phi instructions.
363     llvm::BasicBlock *HeaderBB = CGF.createBasicBlock("loop.header");
364     CGF.EmitBlock(HeaderBB);
365     llvm::PHINode *PHIs[N];
366 
367     for (unsigned I = 0; I < N; ++I) {
368       PHIs[I] = CGF.Builder.CreatePHI(CGF.CGM.Int8PtrPtrTy, 2, "addr.cur");
369       PHIs[I]->addIncoming(StartAddrs[I].getPointer(), PreheaderBB);
370     }
371 
372     // Create the exit and loop body blocks.
373     llvm::BasicBlock *ExitBB = CGF.createBasicBlock("loop.exit");
374     llvm::BasicBlock *LoopBB = CGF.createBasicBlock("loop.body");
375 
376     // Emit the comparison and conditional branch instruction that jumps to
377     // either the exit or the loop body.
378     llvm::Value *Done =
379         CGF.Builder.CreateICmpEQ(PHIs[DstIdx], DstArrayEnd, "done");
380     CGF.Builder.CreateCondBr(Done, ExitBB, LoopBB);
381 
382     // Visit the element of the array in the loop body.
383     CGF.EmitBlock(LoopBB);
384     QualType EltQT = AT->getElementType();
385     CharUnits EltSize = Ctx.getTypeSizeInChars(EltQT);
386     std::array<Address, N> NewAddrs = Addrs;
387 
388     for (unsigned I = 0; I < N; ++I)
389       NewAddrs[I] = Address(
390           PHIs[I], StartAddrs[I].getAlignment().alignmentAtOffset(EltSize));
391 
392     EltQT = IsVolatile ? EltQT.withVolatile() : EltQT;
393     this->asDerived().visitWithKind(FK, EltQT, nullptr, CharUnits::Zero(),
394                                     NewAddrs);
395 
396     LoopBB = CGF.Builder.GetInsertBlock();
397 
398     for (unsigned I = 0; I < N; ++I) {
399       // Instrs to update the destination and source addresses.
400       // Update phi instructions.
401       NewAddrs[I] = getAddrWithOffset(NewAddrs[I], EltSize);
402       PHIs[I]->addIncoming(NewAddrs[I].getPointer(), LoopBB);
403     }
404 
405     // Insert an unconditional branch to the header block.
406     CGF.Builder.CreateBr(HeaderBB);
407     CGF.EmitBlock(ExitBB);
408   }
409 
410   /// Return an address with the specified offset from the passed address.
411   Address getAddrWithOffset(Address Addr, CharUnits Offset) {
412     assert(Addr.isValid() && "invalid address");
413     if (Offset.getQuantity() == 0)
414       return Addr;
415     Addr = CGF->Builder.CreateBitCast(Addr, CGF->CGM.Int8PtrTy);
416     Addr = CGF->Builder.CreateConstInBoundsGEP(Addr, Offset.getQuantity());
417     return CGF->Builder.CreateBitCast(Addr, CGF->CGM.Int8PtrPtrTy);
418   }
419 
420   Address getAddrWithOffset(Address Addr, CharUnits StructFieldOffset,
421                             const FieldDecl *FD) {
422     return getAddrWithOffset(Addr, StructFieldOffset +
423                                        asDerived().getFieldOffset(FD));
424   }
425 
426   template <size_t N>
427   llvm::Function *
428   getFunction(StringRef FuncName, QualType QT, std::array<Address, N> Addrs,
429               std::array<CharUnits, N> Alignments, CodeGenModule &CGM) {
430     // If the special function already exists in the module, return it.
431     if (llvm::Function *F = CGM.getModule().getFunction(FuncName)) {
432       bool WrongType = false;
433       if (!F->getReturnType()->isVoidTy())
434         WrongType = true;
435       else {
436         for (const llvm::Argument &Arg : F->args())
437           if (Arg.getType() != CGM.Int8PtrPtrTy)
438             WrongType = true;
439       }
440 
441       if (WrongType) {
442         std::string FuncName = F->getName();
443         SourceLocation Loc = QT->castAs<RecordType>()->getDecl()->getLocation();
444         CGM.Error(Loc, "special function " + FuncName +
445                            " for non-trivial C struct has incorrect type");
446         return nullptr;
447       }
448       return F;
449     }
450 
451     ASTContext &Ctx = CGM.getContext();
452     FunctionArgList Args;
453     const CGFunctionInfo &FI = getFunctionInfo<N>(CGM, Args);
454     llvm::FunctionType *FuncTy = CGM.getTypes().GetFunctionType(FI);
455     llvm::Function *F =
456         llvm::Function::Create(FuncTy, llvm::GlobalValue::LinkOnceODRLinkage,
457                                FuncName, &CGM.getModule());
458     F->setVisibility(llvm::GlobalValue::HiddenVisibility);
459     CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F);
460     CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
461     IdentifierInfo *II = &Ctx.Idents.get(FuncName);
462     FunctionDecl *FD = FunctionDecl::Create(
463         Ctx, Ctx.getTranslationUnitDecl(), SourceLocation(), SourceLocation(),
464         II, Ctx.getFunctionType(Ctx.VoidTy, llvm::None, {}), nullptr,
465         SC_PrivateExtern, false, false);
466     CodeGenFunction NewCGF(CGM);
467     setCGF(&NewCGF);
468     CGF->StartFunction(FD, Ctx.VoidTy, F, FI, Args);
469 
470     for (unsigned I = 0; I < N; ++I) {
471       llvm::Value *V = CGF->Builder.CreateLoad(CGF->GetAddrOfLocalVar(Args[I]));
472       Addrs[I] = Address(V, Alignments[I]);
473     }
474 
475     asDerived().visitStructFields(QT, CharUnits::Zero(), Addrs);
476     CGF->FinishFunction();
477     return F;
478   }
479 
480   template <size_t N>
481   void callFunc(StringRef FuncName, QualType QT, std::array<Address, N> Addrs,
482                 CodeGenFunction &CallerCGF) {
483     std::array<CharUnits, N> Alignments;
484     llvm::Value *Ptrs[N];
485 
486     for (unsigned I = 0; I < N; ++I) {
487       Alignments[I] = Addrs[I].getAlignment();
488       Ptrs[I] =
489           CallerCGF.Builder.CreateBitCast(Addrs[I], CallerCGF.CGM.Int8PtrPtrTy)
490               .getPointer();
491     }
492 
493     if (llvm::Function *F =
494             getFunction(FuncName, QT, Addrs, Alignments, CallerCGF.CGM))
495       CallerCGF.EmitNounwindRuntimeCall(F, Ptrs);
496   }
497 
498   Derived &asDerived() { return static_cast<Derived &>(*this); }
499 
500   void setCGF(CodeGenFunction *F) { CGF = F; }
501 
502   CodeGenFunction *CGF = nullptr;
503 };
504 
505 template <class Derived, bool IsMove>
506 struct GenBinaryFunc : CopyStructVisitor<Derived, IsMove>,
507                        GenFuncBase<Derived> {
508   GenBinaryFunc(ASTContext &Ctx) : CopyStructVisitor<Derived, IsMove>(Ctx) {}
509 
510   void flushTrivialFields(std::array<Address, 2> Addrs) {
511     CharUnits Size = this->End - this->Start;
512 
513     if (Size.getQuantity() == 0)
514       return;
515 
516     Address DstAddr = this->getAddrWithOffset(Addrs[DstIdx], this->Start);
517     Address SrcAddr = this->getAddrWithOffset(Addrs[SrcIdx], this->Start);
518 
519     // Emit memcpy.
520     if (Size.getQuantity() >= 16 || !llvm::isPowerOf2_32(Size.getQuantity())) {
521       llvm::Value *SizeVal =
522           llvm::ConstantInt::get(this->CGF->SizeTy, Size.getQuantity());
523       DstAddr =
524           this->CGF->Builder.CreateElementBitCast(DstAddr, this->CGF->Int8Ty);
525       SrcAddr =
526           this->CGF->Builder.CreateElementBitCast(SrcAddr, this->CGF->Int8Ty);
527       this->CGF->Builder.CreateMemCpy(DstAddr, SrcAddr, SizeVal, false);
528     } else {
529       llvm::Type *Ty = llvm::Type::getIntNTy(
530           this->CGF->getLLVMContext(),
531           Size.getQuantity() * this->CGF->getContext().getCharWidth());
532       DstAddr = this->CGF->Builder.CreateElementBitCast(DstAddr, Ty);
533       SrcAddr = this->CGF->Builder.CreateElementBitCast(SrcAddr, Ty);
534       llvm::Value *SrcVal = this->CGF->Builder.CreateLoad(SrcAddr, false);
535       this->CGF->Builder.CreateStore(SrcVal, DstAddr, false);
536     }
537 
538     this->Start = this->End = CharUnits::Zero();
539   }
540 
541   template <class... Ts>
542   void visitVolatileTrivial(QualType FT, const FieldDecl *FD, CharUnits Offset,
543                             std::array<Address, 2> Addrs) {
544     LValue DstLV, SrcLV;
545     if (FD) {
546       QualType RT = QualType(FD->getParent()->getTypeForDecl(), 0);
547       llvm::PointerType *PtrTy = this->CGF->ConvertType(RT)->getPointerTo();
548       Address DstAddr = this->getAddrWithOffset(Addrs[DstIdx], Offset);
549       LValue DstBase = this->CGF->MakeAddrLValue(
550           this->CGF->Builder.CreateBitCast(DstAddr, PtrTy), FT);
551       DstLV = this->CGF->EmitLValueForField(DstBase, FD);
552       Address SrcAddr = this->getAddrWithOffset(Addrs[SrcIdx], Offset);
553       LValue SrcBase = this->CGF->MakeAddrLValue(
554           this->CGF->Builder.CreateBitCast(SrcAddr, PtrTy), FT);
555       SrcLV = this->CGF->EmitLValueForField(SrcBase, FD);
556     } else {
557       llvm::PointerType *Ty = this->CGF->ConvertType(FT)->getPointerTo();
558       Address DstAddr = this->CGF->Builder.CreateBitCast(Addrs[DstIdx], Ty);
559       Address SrcAddr = this->CGF->Builder.CreateBitCast(Addrs[SrcIdx], Ty);
560       DstLV = this->CGF->MakeAddrLValue(DstAddr, FT);
561       SrcLV = this->CGF->MakeAddrLValue(SrcAddr, FT);
562     }
563     RValue SrcVal = this->CGF->EmitLoadOfLValue(SrcLV, SourceLocation());
564     this->CGF->EmitStoreThroughLValue(SrcVal, DstLV);
565   }
566 };
567 
568 // These classes that emit the special functions for a non-trivial struct.
569 struct GenDestructor : StructVisitor<GenDestructor>,
570                        GenFuncBase<GenDestructor>,
571                        DestructedTypeVisitor<GenDestructor> {
572   using Super = DestructedTypeVisitor<GenDestructor>;
573   GenDestructor(ASTContext &Ctx) : StructVisitor<GenDestructor>(Ctx) {}
574 
575   void visitWithKind(QualType::DestructionKind DK, QualType FT,
576                      const FieldDecl *FD, CharUnits CurStructOffset,
577                      std::array<Address, 1> Addrs) {
578     if (const auto *AT = getContext().getAsArrayType(FT)) {
579       visitArray(DK, AT, FT.isVolatileQualified(), FD, CurStructOffset, Addrs);
580       return;
581     }
582 
583     Super::visitWithKind(DK, FT, FD, CurStructOffset, Addrs);
584   }
585 
586   void visitARCStrong(QualType QT, const FieldDecl *FD,
587                       CharUnits CurStructOffset, std::array<Address, 1> Addrs) {
588     CGF->destroyARCStrongImprecise(
589         *CGF, getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD), QT);
590   }
591 
592   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
593                     std::array<Address, 1> Addrs) {
594     CGF->destroyARCWeak(
595         *CGF, getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD), QT);
596   }
597 
598   void callSpecialFunction(QualType FT, CharUnits Offset,
599                            std::array<Address, 1> Addrs) {
600     CGF->callCStructDestructor(
601         CGF->MakeAddrLValue(getAddrWithOffset(Addrs[DstIdx], Offset), FT));
602   }
603 };
604 
605 struct GenDefaultInitialize
606     : StructVisitor<GenDefaultInitialize>,
607       GenFuncBase<GenDefaultInitialize>,
608       DefaultInitializedTypeVisitor<GenDefaultInitialize> {
609   using Super = DefaultInitializedTypeVisitor<GenDefaultInitialize>;
610   typedef GenFuncBase<GenDefaultInitialize> GenFuncBaseTy;
611 
612   GenDefaultInitialize(ASTContext &Ctx)
613       : StructVisitor<GenDefaultInitialize>(Ctx) {}
614 
615   void visitWithKind(QualType::PrimitiveDefaultInitializeKind PDIK, QualType FT,
616                      const FieldDecl *FD, CharUnits CurStructOffset,
617                      std::array<Address, 1> Addrs) {
618     if (const auto *AT = getContext().getAsArrayType(FT)) {
619       visitArray(PDIK, AT, FT.isVolatileQualified(), FD, CurStructOffset,
620                  Addrs);
621       return;
622     }
623 
624     Super::visitWithKind(PDIK, FT, FD, CurStructOffset, Addrs);
625   }
626 
627   void visitARCStrong(QualType QT, const FieldDecl *FD,
628                       CharUnits CurStructOffset, std::array<Address, 1> Addrs) {
629     CGF->EmitNullInitialization(
630         getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD), QT);
631   }
632 
633   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
634                     std::array<Address, 1> Addrs) {
635     CGF->EmitNullInitialization(
636         getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD), QT);
637   }
638 
639   template <class FieldKind, size_t... Is>
640   void visitArray(FieldKind FK, const ArrayType *AT, bool IsVolatile,
641                   const FieldDecl *FD, CharUnits CurStructOffset,
642                   std::array<Address, 1> Addrs) {
643     if (!FK)
644       return visitTrivial(QualType(AT, 0), FD, CurStructOffset, Addrs);
645 
646     ASTContext &Ctx = getContext();
647     CharUnits Size = Ctx.getTypeSizeInChars(QualType(AT, 0));
648     QualType EltTy = Ctx.getBaseElementType(QualType(AT, 0));
649 
650     if (Size < CharUnits::fromQuantity(16) || EltTy->getAs<RecordType>()) {
651       GenFuncBaseTy::visitArray(FK, AT, IsVolatile, FD, CurStructOffset, Addrs);
652       return;
653     }
654 
655     llvm::Constant *SizeVal = CGF->Builder.getInt64(Size.getQuantity());
656     Address DstAddr = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
657     Address Loc = CGF->Builder.CreateElementBitCast(DstAddr, CGF->Int8Ty);
658     CGF->Builder.CreateMemSet(Loc, CGF->Builder.getInt8(0), SizeVal,
659                               IsVolatile);
660   }
661 
662   void callSpecialFunction(QualType FT, CharUnits Offset,
663                            std::array<Address, 1> Addrs) {
664     CGF->callCStructDefaultConstructor(
665         CGF->MakeAddrLValue(getAddrWithOffset(Addrs[DstIdx], Offset), FT));
666   }
667 };
668 
669 struct GenCopyConstructor : GenBinaryFunc<GenCopyConstructor, false> {
670   GenCopyConstructor(ASTContext &Ctx)
671       : GenBinaryFunc<GenCopyConstructor, false>(Ctx) {}
672 
673   void visitARCStrong(QualType QT, const FieldDecl *FD,
674                       CharUnits CurStructOffset, std::array<Address, 2> Addrs) {
675     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
676     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
677     llvm::Value *SrcVal = CGF->EmitLoadOfScalar(
678         Addrs[SrcIdx], QT.isVolatileQualified(), QT, SourceLocation());
679     llvm::Value *Val = CGF->EmitARCRetain(QT, SrcVal);
680     CGF->EmitStoreOfScalar(Val, CGF->MakeAddrLValue(Addrs[DstIdx], QT), true);
681   }
682 
683   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
684                     std::array<Address, 2> Addrs) {
685     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
686     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
687     CGF->EmitARCCopyWeak(Addrs[DstIdx], Addrs[SrcIdx]);
688   }
689 
690   void callSpecialFunction(QualType FT, CharUnits Offset,
691                            std::array<Address, 2> Addrs) {
692     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], Offset);
693     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], Offset);
694     CGF->callCStructCopyConstructor(CGF->MakeAddrLValue(Addrs[DstIdx], FT),
695                                     CGF->MakeAddrLValue(Addrs[SrcIdx], FT));
696   }
697 };
698 
699 struct GenMoveConstructor : GenBinaryFunc<GenMoveConstructor, true> {
700   GenMoveConstructor(ASTContext &Ctx)
701       : GenBinaryFunc<GenMoveConstructor, true>(Ctx) {}
702 
703   void visitARCStrong(QualType QT, const FieldDecl *FD,
704                       CharUnits CurStructOffset, std::array<Address, 2> Addrs) {
705     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
706     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
707     LValue SrcLV = CGF->MakeAddrLValue(Addrs[SrcIdx], QT);
708     llvm::Value *SrcVal =
709         CGF->EmitLoadOfLValue(SrcLV, SourceLocation()).getScalarVal();
710     CGF->EmitStoreOfScalar(getNullForVariable(SrcLV.getAddress()), SrcLV);
711     CGF->EmitStoreOfScalar(SrcVal, CGF->MakeAddrLValue(Addrs[DstIdx], QT),
712                            /* isInitialization */ true);
713   }
714 
715   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
716                     std::array<Address, 2> Addrs) {
717     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
718     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
719     CGF->EmitARCMoveWeak(Addrs[DstIdx], Addrs[SrcIdx]);
720   }
721 
722   void callSpecialFunction(QualType FT, CharUnits Offset,
723                            std::array<Address, 2> Addrs) {
724     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], Offset);
725     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], Offset);
726     CGF->callCStructMoveConstructor(CGF->MakeAddrLValue(Addrs[DstIdx], FT),
727                                     CGF->MakeAddrLValue(Addrs[SrcIdx], FT));
728   }
729 };
730 
731 struct GenCopyAssignment : GenBinaryFunc<GenCopyAssignment, false> {
732   GenCopyAssignment(ASTContext &Ctx)
733       : GenBinaryFunc<GenCopyAssignment, false>(Ctx) {}
734 
735   void visitARCStrong(QualType QT, const FieldDecl *FD,
736                       CharUnits CurStructOffset, std::array<Address, 2> Addrs) {
737     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
738     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
739     llvm::Value *SrcVal = CGF->EmitLoadOfScalar(
740         Addrs[SrcIdx], QT.isVolatileQualified(), QT, SourceLocation());
741     CGF->EmitARCStoreStrong(CGF->MakeAddrLValue(Addrs[DstIdx], QT), SrcVal,
742                             false);
743   }
744 
745   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
746                     std::array<Address, 2> Addrs) {
747     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
748     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
749     CGF->emitARCCopyAssignWeak(QT, Addrs[DstIdx], Addrs[SrcIdx]);
750   }
751 
752   void callSpecialFunction(QualType FT, CharUnits Offset,
753                            std::array<Address, 2> Addrs) {
754     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], Offset);
755     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], Offset);
756     CGF->callCStructCopyAssignmentOperator(
757         CGF->MakeAddrLValue(Addrs[DstIdx], FT),
758         CGF->MakeAddrLValue(Addrs[SrcIdx], FT));
759   }
760 };
761 
762 struct GenMoveAssignment : GenBinaryFunc<GenMoveAssignment, true> {
763   GenMoveAssignment(ASTContext &Ctx)
764       : GenBinaryFunc<GenMoveAssignment, true>(Ctx) {}
765 
766   void visitARCStrong(QualType QT, const FieldDecl *FD,
767                       CharUnits CurStructOffset, std::array<Address, 2> Addrs) {
768     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
769     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
770     LValue SrcLV = CGF->MakeAddrLValue(Addrs[SrcIdx], QT);
771     llvm::Value *SrcVal =
772         CGF->EmitLoadOfLValue(SrcLV, SourceLocation()).getScalarVal();
773     CGF->EmitStoreOfScalar(getNullForVariable(SrcLV.getAddress()), SrcLV);
774     LValue DstLV = CGF->MakeAddrLValue(Addrs[DstIdx], QT);
775     llvm::Value *DstVal =
776         CGF->EmitLoadOfLValue(DstLV, SourceLocation()).getScalarVal();
777     CGF->EmitStoreOfScalar(SrcVal, DstLV);
778     CGF->EmitARCRelease(DstVal, ARCImpreciseLifetime);
779   }
780 
781   void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStructOffset,
782                     std::array<Address, 2> Addrs) {
783     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStructOffset, FD);
784     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStructOffset, FD);
785     CGF->emitARCMoveAssignWeak(QT, Addrs[DstIdx], Addrs[SrcIdx]);
786   }
787 
788   void callSpecialFunction(QualType FT, CharUnits Offset,
789                            std::array<Address, 2> Addrs) {
790     Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], Offset);
791     Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], Offset);
792     CGF->callCStructMoveAssignmentOperator(
793         CGF->MakeAddrLValue(Addrs[DstIdx], FT),
794         CGF->MakeAddrLValue(Addrs[SrcIdx], FT));
795   }
796 };
797 
798 } // namespace
799 
800 void CodeGenFunction::destroyNonTrivialCStruct(CodeGenFunction &CGF,
801                                                Address Addr, QualType Type) {
802   CGF.callCStructDestructor(CGF.MakeAddrLValue(Addr, Type));
803 }
804 
805 // Default-initialize a variable that is a non-trivial struct or an array of
806 // such structure.
807 void CodeGenFunction::defaultInitNonTrivialCStructVar(LValue Dst) {
808   GenDefaultInitialize Gen(getContext());
809   Address DstPtr = Builder.CreateBitCast(Dst.getAddress(), CGM.Int8PtrPtrTy);
810   Gen.setCGF(this);
811   QualType QT = Dst.getType();
812   QT = Dst.isVolatile() ? QT.withVolatile() : QT;
813   Gen.visit(QT, nullptr, CharUnits::Zero(), std::array<Address, 1>({{DstPtr}}));
814 }
815 
816 template <class G, size_t N>
817 static void callSpecialFunction(G &&Gen, StringRef FuncName, QualType QT,
818                                 bool IsVolatile, CodeGenFunction &CGF,
819                                 std::array<Address, N> Addrs) {
820   for (unsigned I = 0; I < N; ++I)
821     Addrs[I] = CGF.Builder.CreateBitCast(Addrs[I], CGF.CGM.Int8PtrPtrTy);
822   QT = IsVolatile ? QT.withVolatile() : QT;
823   Gen.callFunc(FuncName, QT, Addrs, CGF);
824 }
825 
826 template <size_t N> static std::array<Address, N> createNullAddressArray();
827 
828 template <> std::array<Address, 1> createNullAddressArray() {
829   return std::array<Address, 1>({{Address(nullptr, CharUnits::Zero())}});
830 }
831 
832 template <> std::array<Address, 2> createNullAddressArray() {
833   return std::array<Address, 2>({{Address(nullptr, CharUnits::Zero()),
834                                   Address(nullptr, CharUnits::Zero())}});
835 }
836 
837 template <class G, size_t N>
838 static llvm::Function *
839 getSpecialFunction(G &&Gen, StringRef FuncName, QualType QT, bool IsVolatile,
840                    std::array<CharUnits, N> Alignments, CodeGenModule &CGM) {
841   QT = IsVolatile ? QT.withVolatile() : QT;
842   // The following call requires an array of addresses as arguments, but doesn't
843   // actually use them (it overwrites them with the addresses of the arguments
844   // of the created function).
845   return Gen.getFunction(FuncName, QT, createNullAddressArray<N>(), Alignments,
846                          CGM);
847 }
848 
849 // Functions to emit calls to the special functions of a non-trivial C struct.
850 void CodeGenFunction::callCStructDefaultConstructor(LValue Dst) {
851   bool IsVolatile = Dst.isVolatile();
852   Address DstPtr = Dst.getAddress();
853   QualType QT = Dst.getType();
854   GenDefaultInitializeFuncName GenName(DstPtr.getAlignment(), getContext());
855   std::string FuncName = GenName.getName(QT, IsVolatile);
856   callSpecialFunction(GenDefaultInitialize(getContext()), FuncName, QT,
857                       IsVolatile, *this, std::array<Address, 1>({{DstPtr}}));
858 }
859 
860 std::string CodeGenFunction::getNonTrivialCopyConstructorStr(
861     QualType QT, CharUnits Alignment, bool IsVolatile, ASTContext &Ctx) {
862   GenBinaryFuncName<false> GenName("", Alignment, Alignment, Ctx);
863   return GenName.getName(QT, IsVolatile);
864 }
865 
866 std::string CodeGenFunction::getNonTrivialDestructorStr(QualType QT,
867                                                         CharUnits Alignment,
868                                                         bool IsVolatile,
869                                                         ASTContext &Ctx) {
870   GenDestructorFuncName GenName("", Alignment, Ctx);
871   return GenName.getName(QT, IsVolatile);
872 }
873 
874 void CodeGenFunction::callCStructDestructor(LValue Dst) {
875   bool IsVolatile = Dst.isVolatile();
876   Address DstPtr = Dst.getAddress();
877   QualType QT = Dst.getType();
878   GenDestructorFuncName GenName("__destructor_", DstPtr.getAlignment(),
879                                 getContext());
880   std::string FuncName = GenName.getName(QT, IsVolatile);
881   callSpecialFunction(GenDestructor(getContext()), FuncName, QT, IsVolatile,
882                       *this, std::array<Address, 1>({{DstPtr}}));
883 }
884 
885 void CodeGenFunction::callCStructCopyConstructor(LValue Dst, LValue Src) {
886   bool IsVolatile = Dst.isVolatile() || Src.isVolatile();
887   Address DstPtr = Dst.getAddress(), SrcPtr = Src.getAddress();
888   QualType QT = Dst.getType();
889   GenBinaryFuncName<false> GenName("__copy_constructor_", DstPtr.getAlignment(),
890                                    SrcPtr.getAlignment(), getContext());
891   std::string FuncName = GenName.getName(QT, IsVolatile);
892   callSpecialFunction(GenCopyConstructor(getContext()), FuncName, QT,
893                       IsVolatile, *this,
894                       std::array<Address, 2>({{DstPtr, SrcPtr}}));
895 }
896 
897 void CodeGenFunction::callCStructCopyAssignmentOperator(LValue Dst, LValue Src
898 
899 ) {
900   bool IsVolatile = Dst.isVolatile() || Src.isVolatile();
901   Address DstPtr = Dst.getAddress(), SrcPtr = Src.getAddress();
902   QualType QT = Dst.getType();
903   GenBinaryFuncName<false> GenName("__copy_assignment_", DstPtr.getAlignment(),
904                                    SrcPtr.getAlignment(), getContext());
905   std::string FuncName = GenName.getName(QT, IsVolatile);
906   callSpecialFunction(GenCopyAssignment(getContext()), FuncName, QT, IsVolatile,
907                       *this, std::array<Address, 2>({{DstPtr, SrcPtr}}));
908 }
909 
910 void CodeGenFunction::callCStructMoveConstructor(LValue Dst, LValue Src) {
911   bool IsVolatile = Dst.isVolatile() || Src.isVolatile();
912   Address DstPtr = Dst.getAddress(), SrcPtr = Src.getAddress();
913   QualType QT = Dst.getType();
914   GenBinaryFuncName<true> GenName("__move_constructor_", DstPtr.getAlignment(),
915                                   SrcPtr.getAlignment(), getContext());
916   std::string FuncName = GenName.getName(QT, IsVolatile);
917   callSpecialFunction(GenMoveConstructor(getContext()), FuncName, QT,
918                       IsVolatile, *this,
919                       std::array<Address, 2>({{DstPtr, SrcPtr}}));
920 }
921 
922 void CodeGenFunction::callCStructMoveAssignmentOperator(LValue Dst, LValue Src
923 
924 ) {
925   bool IsVolatile = Dst.isVolatile() || Src.isVolatile();
926   Address DstPtr = Dst.getAddress(), SrcPtr = Src.getAddress();
927   QualType QT = Dst.getType();
928   GenBinaryFuncName<true> GenName("__move_assignment_", DstPtr.getAlignment(),
929                                   SrcPtr.getAlignment(), getContext());
930   std::string FuncName = GenName.getName(QT, IsVolatile);
931   callSpecialFunction(GenMoveAssignment(getContext()), FuncName, QT, IsVolatile,
932                       *this, std::array<Address, 2>({{DstPtr, SrcPtr}}));
933 }
934 
935 llvm::Function *clang::CodeGen::getNonTrivialCStructDefaultConstructor(
936     CodeGenModule &CGM, CharUnits DstAlignment, bool IsVolatile, QualType QT) {
937   ASTContext &Ctx = CGM.getContext();
938   GenDefaultInitializeFuncName GenName(DstAlignment, Ctx);
939   std::string FuncName = GenName.getName(QT, IsVolatile);
940   return getSpecialFunction(GenDefaultInitialize(Ctx), FuncName, QT, IsVolatile,
941                             std::array<CharUnits, 1>({{DstAlignment}}), CGM);
942 }
943 
944 llvm::Function *clang::CodeGen::getNonTrivialCStructCopyConstructor(
945     CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
946     bool IsVolatile, QualType QT) {
947   ASTContext &Ctx = CGM.getContext();
948   GenBinaryFuncName<false> GenName("__copy_constructor_", DstAlignment,
949                                    SrcAlignment, Ctx);
950   std::string FuncName = GenName.getName(QT, IsVolatile);
951   return getSpecialFunction(
952       GenCopyConstructor(Ctx), FuncName, QT, IsVolatile,
953       std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
954 }
955 
956 llvm::Function *clang::CodeGen::getNonTrivialCStructMoveConstructor(
957     CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
958     bool IsVolatile, QualType QT) {
959   ASTContext &Ctx = CGM.getContext();
960   GenBinaryFuncName<true> GenName("__move_constructor_", DstAlignment,
961                                   SrcAlignment, Ctx);
962   std::string FuncName = GenName.getName(QT, IsVolatile);
963   return getSpecialFunction(
964       GenMoveConstructor(Ctx), FuncName, QT, IsVolatile,
965       std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
966 }
967 
968 llvm::Function *clang::CodeGen::getNonTrivialCStructCopyAssignmentOperator(
969     CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
970     bool IsVolatile, QualType QT) {
971   ASTContext &Ctx = CGM.getContext();
972   GenBinaryFuncName<false> GenName("__copy_assignment_", DstAlignment,
973                                    SrcAlignment, Ctx);
974   std::string FuncName = GenName.getName(QT, IsVolatile);
975   return getSpecialFunction(
976       GenCopyAssignment(Ctx), FuncName, QT, IsVolatile,
977       std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
978 }
979 
980 llvm::Function *clang::CodeGen::getNonTrivialCStructMoveAssignmentOperator(
981     CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
982     bool IsVolatile, QualType QT) {
983   ASTContext &Ctx = CGM.getContext();
984   GenBinaryFuncName<true> GenName("__move_assignment_", DstAlignment,
985                                   SrcAlignment, Ctx);
986   std::string FuncName = GenName.getName(QT, IsVolatile);
987   return getSpecialFunction(
988       GenMoveAssignment(Ctx), FuncName, QT, IsVolatile,
989       std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
990 }
991 
992 llvm::Function *clang::CodeGen::getNonTrivialCStructDestructor(
993     CodeGenModule &CGM, CharUnits DstAlignment, bool IsVolatile, QualType QT) {
994   ASTContext &Ctx = CGM.getContext();
995   GenDestructorFuncName GenName("__destructor_", DstAlignment, Ctx);
996   std::string FuncName = GenName.getName(QT, IsVolatile);
997   return getSpecialFunction(GenDestructor(Ctx), FuncName, QT, IsVolatile,
998                             std::array<CharUnits, 1>({{DstAlignment}}), CGM);
999 }
1000