ItaniumCXXABI.cpp revision 249423
1208600Srdivacky//===------- ItaniumCXXABI.cpp - Emit LLVM Code from ASTs for a Module ----===// 2208600Srdivacky// 3208600Srdivacky// The LLVM Compiler Infrastructure 4208600Srdivacky// 5208600Srdivacky// This file is distributed under the University of Illinois Open Source 6208600Srdivacky// License. See LICENSE.TXT for details. 7208600Srdivacky// 8208600Srdivacky//===----------------------------------------------------------------------===// 9208600Srdivacky// 10221345Sdim// This provides C++ code generation targeting the Itanium C++ ABI. The class 11208600Srdivacky// in this file generates structures that follow the Itanium C++ ABI, which is 12208600Srdivacky// documented at: 13208600Srdivacky// http://www.codesourcery.com/public/cxx-abi/abi.html 14208600Srdivacky// http://www.codesourcery.com/public/cxx-abi/abi-eh.html 15212904Sdim// 16212904Sdim// It also supports the closely-related ARM ABI, documented at: 17212904Sdim// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0041c/IHI0041C_cppabi.pdf 18212904Sdim// 19208600Srdivacky//===----------------------------------------------------------------------===// 20208600Srdivacky 21208600Srdivacky#include "CGCXXABI.h" 22212904Sdim#include "CGRecordLayout.h" 23239462Sdim#include "CGVTables.h" 24212904Sdim#include "CodeGenFunction.h" 25208600Srdivacky#include "CodeGenModule.h" 26243830Sdim#include "clang/AST/Mangle.h" 27243830Sdim#include "clang/AST/Type.h" 28249423Sdim#include "llvm/IR/DataLayout.h" 29249423Sdim#include "llvm/IR/Intrinsics.h" 30249423Sdim#include "llvm/IR/Value.h" 31208600Srdivacky 32208600Srdivackyusing namespace clang; 33212904Sdimusing namespace CodeGen; 34208600Srdivacky 35208600Srdivackynamespace { 36212904Sdimclass ItaniumCXXABI : public CodeGen::CGCXXABI { 37212904Sdimprotected: 38212904Sdim bool IsARM; 39212904Sdim 40208600Srdivackypublic: 41212904Sdim ItaniumCXXABI(CodeGen::CodeGenModule &CGM, bool IsARM = false) : 42249423Sdim CGCXXABI(CGM), IsARM(IsARM) { } 43208600Srdivacky 44212904Sdim bool isZeroInitializable(const MemberPointerType *MPT); 45212904Sdim 46224145Sdim llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT); 47212904Sdim 48212904Sdim llvm::Value *EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, 49212904Sdim llvm::Value *&This, 50212904Sdim llvm::Value *MemFnPtr, 51212904Sdim const MemberPointerType *MPT); 52212904Sdim 53212904Sdim llvm::Value *EmitMemberDataPointerAddress(CodeGenFunction &CGF, 54212904Sdim llvm::Value *Base, 55212904Sdim llvm::Value *MemPtr, 56212904Sdim const MemberPointerType *MPT); 57212904Sdim 58212904Sdim llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF, 59212904Sdim const CastExpr *E, 60212904Sdim llvm::Value *Src); 61234353Sdim llvm::Constant *EmitMemberPointerConversion(const CastExpr *E, 62234353Sdim llvm::Constant *Src); 63212904Sdim 64212904Sdim llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT); 65212904Sdim 66212904Sdim llvm::Constant *EmitMemberPointer(const CXXMethodDecl *MD); 67218893Sdim llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT, 68218893Sdim CharUnits offset); 69234353Sdim llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT); 70234353Sdim llvm::Constant *BuildMemberPointer(const CXXMethodDecl *MD, 71234353Sdim CharUnits ThisAdjustment); 72212904Sdim 73212904Sdim llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF, 74212904Sdim llvm::Value *L, 75212904Sdim llvm::Value *R, 76212904Sdim const MemberPointerType *MPT, 77212904Sdim bool Inequality); 78212904Sdim 79212904Sdim llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF, 80212904Sdim llvm::Value *Addr, 81212904Sdim const MemberPointerType *MPT); 82212904Sdim 83243830Sdim llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, 84243830Sdim llvm::Value *ptr, 85243830Sdim QualType type); 86243830Sdim 87212904Sdim void BuildConstructorSignature(const CXXConstructorDecl *Ctor, 88212904Sdim CXXCtorType T, 89212904Sdim CanQualType &ResTy, 90226633Sdim SmallVectorImpl<CanQualType> &ArgTys); 91212904Sdim 92212904Sdim void BuildDestructorSignature(const CXXDestructorDecl *Dtor, 93212904Sdim CXXDtorType T, 94212904Sdim CanQualType &ResTy, 95226633Sdim SmallVectorImpl<CanQualType> &ArgTys); 96212904Sdim 97212904Sdim void BuildInstanceFunctionParams(CodeGenFunction &CGF, 98212904Sdim QualType &ResTy, 99212904Sdim FunctionArgList &Params); 100212904Sdim 101212904Sdim void EmitInstanceFunctionProlog(CodeGenFunction &CGF); 102212904Sdim 103249423Sdim llvm::Value *EmitConstructorCall(CodeGenFunction &CGF, 104249423Sdim const CXXConstructorDecl *D, 105249423Sdim CXXCtorType Type, bool ForVirtualBase, 106249423Sdim bool Delegating, 107249423Sdim llvm::Value *This, 108249423Sdim CallExpr::const_arg_iterator ArgBeg, 109249423Sdim CallExpr::const_arg_iterator ArgEnd); 110249423Sdim 111249423Sdim RValue EmitVirtualDestructorCall(CodeGenFunction &CGF, 112249423Sdim const CXXDestructorDecl *Dtor, 113249423Sdim CXXDtorType DtorType, 114249423Sdim SourceLocation CallLoc, 115249423Sdim ReturnValueSlot ReturnValue, 116249423Sdim llvm::Value *This); 117249423Sdim 118239462Sdim StringRef GetPureVirtualCallName() { return "__cxa_pure_virtual"; } 119243830Sdim StringRef GetDeletedVirtualCallName() { return "__cxa_deleted_virtual"; } 120239462Sdim 121239462Sdim CharUnits getArrayCookieSizeImpl(QualType elementType); 122212904Sdim llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF, 123212904Sdim llvm::Value *NewPtr, 124212904Sdim llvm::Value *NumElements, 125218893Sdim const CXXNewExpr *expr, 126212904Sdim QualType ElementType); 127239462Sdim llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF, 128239462Sdim llvm::Value *allocPtr, 129239462Sdim CharUnits cookieSize); 130218893Sdim 131218893Sdim void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, 132234353Sdim llvm::GlobalVariable *DeclPtr, bool PerformInit); 133239462Sdim void registerGlobalDtor(CodeGenFunction &CGF, llvm::Constant *dtor, 134239462Sdim llvm::Constant *addr); 135208600Srdivacky}; 136212904Sdim 137212904Sdimclass ARMCXXABI : public ItaniumCXXABI { 138212904Sdimpublic: 139212904Sdim ARMCXXABI(CodeGen::CodeGenModule &CGM) : ItaniumCXXABI(CGM, /*ARM*/ true) {} 140212904Sdim 141212904Sdim void BuildConstructorSignature(const CXXConstructorDecl *Ctor, 142212904Sdim CXXCtorType T, 143212904Sdim CanQualType &ResTy, 144226633Sdim SmallVectorImpl<CanQualType> &ArgTys); 145212904Sdim 146212904Sdim void BuildDestructorSignature(const CXXDestructorDecl *Dtor, 147212904Sdim CXXDtorType T, 148212904Sdim CanQualType &ResTy, 149226633Sdim SmallVectorImpl<CanQualType> &ArgTys); 150212904Sdim 151212904Sdim void BuildInstanceFunctionParams(CodeGenFunction &CGF, 152212904Sdim QualType &ResTy, 153212904Sdim FunctionArgList &Params); 154212904Sdim 155212904Sdim void EmitInstanceFunctionProlog(CodeGenFunction &CGF); 156212904Sdim 157212904Sdim void EmitReturnFromThunk(CodeGenFunction &CGF, RValue RV, QualType ResTy); 158212904Sdim 159239462Sdim CharUnits getArrayCookieSizeImpl(QualType elementType); 160212904Sdim llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF, 161212904Sdim llvm::Value *NewPtr, 162212904Sdim llvm::Value *NumElements, 163218893Sdim const CXXNewExpr *expr, 164212904Sdim QualType ElementType); 165239462Sdim llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF, llvm::Value *allocPtr, 166239462Sdim CharUnits cookieSize); 167212904Sdim 168212904Sdim /// \brief Returns true if the given instance method is one of the 169212904Sdim /// kinds that the ARM ABI says returns 'this'. 170249423Sdim bool HasThisReturn(GlobalDecl GD) const { 171249423Sdim const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(GD.getDecl()); 172249423Sdim if (!MD) return false; 173212904Sdim return ((isa<CXXDestructorDecl>(MD) && GD.getDtorType() != Dtor_Deleting) || 174212904Sdim (isa<CXXConstructorDecl>(MD))); 175212904Sdim } 176212904Sdim}; 177208600Srdivacky} 178208600Srdivacky 179212904SdimCodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) { 180249423Sdim switch (CGM.getContext().getTargetInfo().getCXXABI().getKind()) { 181249423Sdim // For IR-generation purposes, there's no significant difference 182249423Sdim // between the ARM and iOS ABIs. 183249423Sdim case TargetCXXABI::GenericARM: 184249423Sdim case TargetCXXABI::iOS: 185249423Sdim return new ARMCXXABI(CGM); 186208600Srdivacky 187249423Sdim // Note that AArch64 uses the generic ItaniumCXXABI class since it doesn't 188249423Sdim // include the other 32-bit ARM oddities: constructor/destructor return values 189249423Sdim // and array cookies. 190249423Sdim case TargetCXXABI::GenericAArch64: 191249423Sdim return new ItaniumCXXABI(CGM, /*IsARM = */ true); 192249423Sdim 193249423Sdim case TargetCXXABI::GenericItanium: 194249423Sdim return new ItaniumCXXABI(CGM); 195249423Sdim 196249423Sdim case TargetCXXABI::Microsoft: 197249423Sdim llvm_unreachable("Microsoft ABI is not Itanium-based"); 198249423Sdim } 199249423Sdim llvm_unreachable("bad ABI kind"); 200212904Sdim} 201212904Sdim 202224145Sdimllvm::Type * 203212904SdimItaniumCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) { 204212904Sdim if (MPT->isMemberDataPointer()) 205249423Sdim return CGM.PtrDiffTy; 206249423Sdim return llvm::StructType::get(CGM.PtrDiffTy, CGM.PtrDiffTy, NULL); 207212904Sdim} 208212904Sdim 209212904Sdim/// In the Itanium and ARM ABIs, method pointers have the form: 210212904Sdim/// struct { ptrdiff_t ptr; ptrdiff_t adj; } memptr; 211212904Sdim/// 212212904Sdim/// In the Itanium ABI: 213212904Sdim/// - method pointers are virtual if (memptr.ptr & 1) is nonzero 214212904Sdim/// - the this-adjustment is (memptr.adj) 215212904Sdim/// - the virtual offset is (memptr.ptr - 1) 216212904Sdim/// 217212904Sdim/// In the ARM ABI: 218212904Sdim/// - method pointers are virtual if (memptr.adj & 1) is nonzero 219212904Sdim/// - the this-adjustment is (memptr.adj >> 1) 220212904Sdim/// - the virtual offset is (memptr.ptr) 221212904Sdim/// ARM uses 'adj' for the virtual flag because Thumb functions 222212904Sdim/// may be only single-byte aligned. 223212904Sdim/// 224212904Sdim/// If the member is virtual, the adjusted 'this' pointer points 225212904Sdim/// to a vtable pointer from which the virtual offset is applied. 226212904Sdim/// 227212904Sdim/// If the member is non-virtual, memptr.ptr is the address of 228212904Sdim/// the function to call. 229212904Sdimllvm::Value * 230212904SdimItaniumCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, 231212904Sdim llvm::Value *&This, 232212904Sdim llvm::Value *MemFnPtr, 233212904Sdim const MemberPointerType *MPT) { 234212904Sdim CGBuilderTy &Builder = CGF.Builder; 235212904Sdim 236212904Sdim const FunctionProtoType *FPT = 237212904Sdim MPT->getPointeeType()->getAs<FunctionProtoType>(); 238212904Sdim const CXXRecordDecl *RD = 239212904Sdim cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl()); 240212904Sdim 241226633Sdim llvm::FunctionType *FTy = 242234353Sdim CGM.getTypes().GetFunctionType( 243234353Sdim CGM.getTypes().arrangeCXXMethodType(RD, FPT)); 244212904Sdim 245249423Sdim llvm::Constant *ptrdiff_1 = llvm::ConstantInt::get(CGM.PtrDiffTy, 1); 246212904Sdim 247212904Sdim llvm::BasicBlock *FnVirtual = CGF.createBasicBlock("memptr.virtual"); 248212904Sdim llvm::BasicBlock *FnNonVirtual = CGF.createBasicBlock("memptr.nonvirtual"); 249212904Sdim llvm::BasicBlock *FnEnd = CGF.createBasicBlock("memptr.end"); 250212904Sdim 251212904Sdim // Extract memptr.adj, which is in the second field. 252212904Sdim llvm::Value *RawAdj = Builder.CreateExtractValue(MemFnPtr, 1, "memptr.adj"); 253212904Sdim 254212904Sdim // Compute the true adjustment. 255212904Sdim llvm::Value *Adj = RawAdj; 256212904Sdim if (IsARM) 257212904Sdim Adj = Builder.CreateAShr(Adj, ptrdiff_1, "memptr.adj.shifted"); 258212904Sdim 259212904Sdim // Apply the adjustment and cast back to the original struct type 260212904Sdim // for consistency. 261212904Sdim llvm::Value *Ptr = Builder.CreateBitCast(This, Builder.getInt8PtrTy()); 262212904Sdim Ptr = Builder.CreateInBoundsGEP(Ptr, Adj); 263212904Sdim This = Builder.CreateBitCast(Ptr, This->getType(), "this.adjusted"); 264212904Sdim 265212904Sdim // Load the function pointer. 266212904Sdim llvm::Value *FnAsInt = Builder.CreateExtractValue(MemFnPtr, 0, "memptr.ptr"); 267212904Sdim 268212904Sdim // If the LSB in the function pointer is 1, the function pointer points to 269212904Sdim // a virtual function. 270212904Sdim llvm::Value *IsVirtual; 271212904Sdim if (IsARM) 272212904Sdim IsVirtual = Builder.CreateAnd(RawAdj, ptrdiff_1); 273212904Sdim else 274212904Sdim IsVirtual = Builder.CreateAnd(FnAsInt, ptrdiff_1); 275212904Sdim IsVirtual = Builder.CreateIsNotNull(IsVirtual, "memptr.isvirtual"); 276212904Sdim Builder.CreateCondBr(IsVirtual, FnVirtual, FnNonVirtual); 277212904Sdim 278212904Sdim // In the virtual path, the adjustment left 'This' pointing to the 279212904Sdim // vtable of the correct base subobject. The "function pointer" is an 280212904Sdim // offset within the vtable (+1 for the virtual flag on non-ARM). 281212904Sdim CGF.EmitBlock(FnVirtual); 282212904Sdim 283212904Sdim // Cast the adjusted this to a pointer to vtable pointer and load. 284226633Sdim llvm::Type *VTableTy = Builder.getInt8PtrTy(); 285212904Sdim llvm::Value *VTable = Builder.CreateBitCast(This, VTableTy->getPointerTo()); 286212904Sdim VTable = Builder.CreateLoad(VTable, "memptr.vtable"); 287212904Sdim 288212904Sdim // Apply the offset. 289212904Sdim llvm::Value *VTableOffset = FnAsInt; 290212904Sdim if (!IsARM) VTableOffset = Builder.CreateSub(VTableOffset, ptrdiff_1); 291212904Sdim VTable = Builder.CreateGEP(VTable, VTableOffset); 292212904Sdim 293212904Sdim // Load the virtual function to call. 294212904Sdim VTable = Builder.CreateBitCast(VTable, FTy->getPointerTo()->getPointerTo()); 295212904Sdim llvm::Value *VirtualFn = Builder.CreateLoad(VTable, "memptr.virtualfn"); 296212904Sdim CGF.EmitBranch(FnEnd); 297212904Sdim 298212904Sdim // In the non-virtual path, the function pointer is actually a 299212904Sdim // function pointer. 300212904Sdim CGF.EmitBlock(FnNonVirtual); 301212904Sdim llvm::Value *NonVirtualFn = 302212904Sdim Builder.CreateIntToPtr(FnAsInt, FTy->getPointerTo(), "memptr.nonvirtualfn"); 303212904Sdim 304212904Sdim // We're done. 305212904Sdim CGF.EmitBlock(FnEnd); 306221345Sdim llvm::PHINode *Callee = Builder.CreatePHI(FTy->getPointerTo(), 2); 307212904Sdim Callee->addIncoming(VirtualFn, FnVirtual); 308212904Sdim Callee->addIncoming(NonVirtualFn, FnNonVirtual); 309212904Sdim return Callee; 310212904Sdim} 311212904Sdim 312212904Sdim/// Compute an l-value by applying the given pointer-to-member to a 313212904Sdim/// base object. 314212904Sdimllvm::Value *ItaniumCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF, 315212904Sdim llvm::Value *Base, 316212904Sdim llvm::Value *MemPtr, 317212904Sdim const MemberPointerType *MPT) { 318249423Sdim assert(MemPtr->getType() == CGM.PtrDiffTy); 319212904Sdim 320212904Sdim CGBuilderTy &Builder = CGF.Builder; 321212904Sdim 322243830Sdim unsigned AS = Base->getType()->getPointerAddressSpace(); 323212904Sdim 324212904Sdim // Cast to char*. 325212904Sdim Base = Builder.CreateBitCast(Base, Builder.getInt8Ty()->getPointerTo(AS)); 326212904Sdim 327212904Sdim // Apply the offset, which we assume is non-null. 328212904Sdim llvm::Value *Addr = Builder.CreateInBoundsGEP(Base, MemPtr, "memptr.offset"); 329212904Sdim 330212904Sdim // Cast the address to the appropriate pointer type, adopting the 331212904Sdim // address space of the base pointer. 332226633Sdim llvm::Type *PType 333212904Sdim = CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS); 334212904Sdim return Builder.CreateBitCast(Addr, PType); 335212904Sdim} 336212904Sdim 337234353Sdim/// Perform a bitcast, derived-to-base, or base-to-derived member pointer 338234353Sdim/// conversion. 339212904Sdim/// 340234353Sdim/// Bitcast conversions are always a no-op under Itanium. 341234353Sdim/// 342212904Sdim/// Obligatory offset/adjustment diagram: 343212904Sdim/// <-- offset --> <-- adjustment --> 344212904Sdim/// |--------------------------|----------------------|--------------------| 345212904Sdim/// ^Derived address point ^Base address point ^Member address point 346212904Sdim/// 347212904Sdim/// So when converting a base member pointer to a derived member pointer, 348212904Sdim/// we add the offset to the adjustment because the address point has 349212904Sdim/// decreased; and conversely, when converting a derived MP to a base MP 350212904Sdim/// we subtract the offset from the adjustment because the address point 351212904Sdim/// has increased. 352212904Sdim/// 353212904Sdim/// The standard forbids (at compile time) conversion to and from 354212904Sdim/// virtual bases, which is why we don't have to consider them here. 355212904Sdim/// 356212904Sdim/// The standard forbids (at run time) casting a derived MP to a base 357212904Sdim/// MP when the derived MP does not point to a member of the base. 358212904Sdim/// This is why -1 is a reasonable choice for null data member 359212904Sdim/// pointers. 360212904Sdimllvm::Value * 361212904SdimItaniumCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF, 362212904Sdim const CastExpr *E, 363234353Sdim llvm::Value *src) { 364212904Sdim assert(E->getCastKind() == CK_DerivedToBaseMemberPointer || 365234353Sdim E->getCastKind() == CK_BaseToDerivedMemberPointer || 366234353Sdim E->getCastKind() == CK_ReinterpretMemberPointer); 367212904Sdim 368234353Sdim // Under Itanium, reinterprets don't require any additional processing. 369234353Sdim if (E->getCastKind() == CK_ReinterpretMemberPointer) return src; 370212904Sdim 371234353Sdim // Use constant emission if we can. 372234353Sdim if (isa<llvm::Constant>(src)) 373234353Sdim return EmitMemberPointerConversion(E, cast<llvm::Constant>(src)); 374212904Sdim 375234353Sdim llvm::Constant *adj = getMemberPointerAdjustment(E); 376234353Sdim if (!adj) return src; 377212904Sdim 378234353Sdim CGBuilderTy &Builder = CGF.Builder; 379234353Sdim bool isDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer); 380212904Sdim 381234353Sdim const MemberPointerType *destTy = 382234353Sdim E->getType()->castAs<MemberPointerType>(); 383212904Sdim 384212904Sdim // For member data pointers, this is just a matter of adding the 385212904Sdim // offset if the source is non-null. 386234353Sdim if (destTy->isMemberDataPointer()) { 387234353Sdim llvm::Value *dst; 388234353Sdim if (isDerivedToBase) 389234353Sdim dst = Builder.CreateNSWSub(src, adj, "adj"); 390212904Sdim else 391234353Sdim dst = Builder.CreateNSWAdd(src, adj, "adj"); 392212904Sdim 393212904Sdim // Null check. 394234353Sdim llvm::Value *null = llvm::Constant::getAllOnesValue(src->getType()); 395234353Sdim llvm::Value *isNull = Builder.CreateICmpEQ(src, null, "memptr.isnull"); 396234353Sdim return Builder.CreateSelect(isNull, src, dst); 397212904Sdim } 398212904Sdim 399212904Sdim // The this-adjustment is left-shifted by 1 on ARM. 400212904Sdim if (IsARM) { 401234353Sdim uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue(); 402234353Sdim offset <<= 1; 403234353Sdim adj = llvm::ConstantInt::get(adj->getType(), offset); 404212904Sdim } 405212904Sdim 406234353Sdim llvm::Value *srcAdj = Builder.CreateExtractValue(src, 1, "src.adj"); 407234353Sdim llvm::Value *dstAdj; 408234353Sdim if (isDerivedToBase) 409234353Sdim dstAdj = Builder.CreateNSWSub(srcAdj, adj, "adj"); 410212904Sdim else 411234353Sdim dstAdj = Builder.CreateNSWAdd(srcAdj, adj, "adj"); 412212904Sdim 413234353Sdim return Builder.CreateInsertValue(src, dstAdj, 1); 414212904Sdim} 415212904Sdim 416212904Sdimllvm::Constant * 417234353SdimItaniumCXXABI::EmitMemberPointerConversion(const CastExpr *E, 418234353Sdim llvm::Constant *src) { 419234353Sdim assert(E->getCastKind() == CK_DerivedToBaseMemberPointer || 420234353Sdim E->getCastKind() == CK_BaseToDerivedMemberPointer || 421234353Sdim E->getCastKind() == CK_ReinterpretMemberPointer); 422212904Sdim 423234353Sdim // Under Itanium, reinterprets don't require any additional processing. 424234353Sdim if (E->getCastKind() == CK_ReinterpretMemberPointer) return src; 425212904Sdim 426234353Sdim // If the adjustment is trivial, we don't need to do anything. 427234353Sdim llvm::Constant *adj = getMemberPointerAdjustment(E); 428234353Sdim if (!adj) return src; 429212904Sdim 430234353Sdim bool isDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer); 431212904Sdim 432234353Sdim const MemberPointerType *destTy = 433234353Sdim E->getType()->castAs<MemberPointerType>(); 434212904Sdim 435234353Sdim // For member data pointers, this is just a matter of adding the 436234353Sdim // offset if the source is non-null. 437234353Sdim if (destTy->isMemberDataPointer()) { 438234353Sdim // null maps to null. 439234353Sdim if (src->isAllOnesValue()) return src; 440212904Sdim 441234353Sdim if (isDerivedToBase) 442234353Sdim return llvm::ConstantExpr::getNSWSub(src, adj); 443212904Sdim else 444234353Sdim return llvm::ConstantExpr::getNSWAdd(src, adj); 445212904Sdim } 446212904Sdim 447212904Sdim // The this-adjustment is left-shifted by 1 on ARM. 448212904Sdim if (IsARM) { 449234353Sdim uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue(); 450234353Sdim offset <<= 1; 451234353Sdim adj = llvm::ConstantInt::get(adj->getType(), offset); 452212904Sdim } 453212904Sdim 454234353Sdim llvm::Constant *srcAdj = llvm::ConstantExpr::getExtractValue(src, 1); 455234353Sdim llvm::Constant *dstAdj; 456234353Sdim if (isDerivedToBase) 457234353Sdim dstAdj = llvm::ConstantExpr::getNSWSub(srcAdj, adj); 458212904Sdim else 459234353Sdim dstAdj = llvm::ConstantExpr::getNSWAdd(srcAdj, adj); 460212904Sdim 461234353Sdim return llvm::ConstantExpr::getInsertValue(src, dstAdj, 1); 462234353Sdim} 463212904Sdim 464212904Sdimllvm::Constant * 465212904SdimItaniumCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) { 466212904Sdim // Itanium C++ ABI 2.3: 467212904Sdim // A NULL pointer is represented as -1. 468212904Sdim if (MPT->isMemberDataPointer()) 469249423Sdim return llvm::ConstantInt::get(CGM.PtrDiffTy, -1ULL, /*isSigned=*/true); 470212904Sdim 471249423Sdim llvm::Constant *Zero = llvm::ConstantInt::get(CGM.PtrDiffTy, 0); 472212904Sdim llvm::Constant *Values[2] = { Zero, Zero }; 473224145Sdim return llvm::ConstantStruct::getAnon(Values); 474212904Sdim} 475212904Sdim 476218893Sdimllvm::Constant * 477218893SdimItaniumCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT, 478218893Sdim CharUnits offset) { 479212904Sdim // Itanium C++ ABI 2.3: 480212904Sdim // A pointer to data member is an offset from the base address of 481212904Sdim // the class object containing it, represented as a ptrdiff_t 482249423Sdim return llvm::ConstantInt::get(CGM.PtrDiffTy, offset.getQuantity()); 483212904Sdim} 484212904Sdim 485212904Sdimllvm::Constant *ItaniumCXXABI::EmitMemberPointer(const CXXMethodDecl *MD) { 486234353Sdim return BuildMemberPointer(MD, CharUnits::Zero()); 487234353Sdim} 488234353Sdim 489234353Sdimllvm::Constant *ItaniumCXXABI::BuildMemberPointer(const CXXMethodDecl *MD, 490234353Sdim CharUnits ThisAdjustment) { 491212904Sdim assert(MD->isInstance() && "Member function must not be static!"); 492212904Sdim MD = MD->getCanonicalDecl(); 493212904Sdim 494212904Sdim CodeGenTypes &Types = CGM.getTypes(); 495212904Sdim 496212904Sdim // Get the function pointer (or index if this is a virtual function). 497212904Sdim llvm::Constant *MemPtr[2]; 498212904Sdim if (MD->isVirtual()) { 499226633Sdim uint64_t Index = CGM.getVTableContext().getMethodVTableIndex(MD); 500212904Sdim 501221345Sdim const ASTContext &Context = getContext(); 502221345Sdim CharUnits PointerWidth = 503226633Sdim Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0)); 504221345Sdim uint64_t VTableOffset = (Index * PointerWidth.getQuantity()); 505212904Sdim 506212904Sdim if (IsARM) { 507212904Sdim // ARM C++ ABI 3.2.1: 508212904Sdim // This ABI specifies that adj contains twice the this 509212904Sdim // adjustment, plus 1 if the member function is virtual. The 510212904Sdim // least significant bit of adj then makes exactly the same 511212904Sdim // discrimination as the least significant bit of ptr does for 512212904Sdim // Itanium. 513249423Sdim MemPtr[0] = llvm::ConstantInt::get(CGM.PtrDiffTy, VTableOffset); 514249423Sdim MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy, 515234353Sdim 2 * ThisAdjustment.getQuantity() + 1); 516212904Sdim } else { 517212904Sdim // Itanium C++ ABI 2.3: 518212904Sdim // For a virtual function, [the pointer field] is 1 plus the 519212904Sdim // virtual table offset (in bytes) of the function, 520212904Sdim // represented as a ptrdiff_t. 521249423Sdim MemPtr[0] = llvm::ConstantInt::get(CGM.PtrDiffTy, VTableOffset + 1); 522249423Sdim MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy, 523234353Sdim ThisAdjustment.getQuantity()); 524212904Sdim } 525212904Sdim } else { 526221345Sdim const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); 527226633Sdim llvm::Type *Ty; 528212904Sdim // Check whether the function has a computable LLVM signature. 529224145Sdim if (Types.isFuncTypeConvertible(FPT)) { 530212904Sdim // The function has a computable LLVM signature; use the correct type. 531234353Sdim Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD)); 532212904Sdim } else { 533212904Sdim // Use an arbitrary non-function type to tell GetAddrOfFunction that the 534212904Sdim // function type is incomplete. 535249423Sdim Ty = CGM.PtrDiffTy; 536212904Sdim } 537221345Sdim llvm::Constant *addr = CGM.GetAddrOfFunction(MD, Ty); 538212904Sdim 539249423Sdim MemPtr[0] = llvm::ConstantExpr::getPtrToInt(addr, CGM.PtrDiffTy); 540249423Sdim MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy, (IsARM ? 2 : 1) * 541234353Sdim ThisAdjustment.getQuantity()); 542212904Sdim } 543212904Sdim 544224145Sdim return llvm::ConstantStruct::getAnon(MemPtr); 545212904Sdim} 546212904Sdim 547234353Sdimllvm::Constant *ItaniumCXXABI::EmitMemberPointer(const APValue &MP, 548234353Sdim QualType MPType) { 549234353Sdim const MemberPointerType *MPT = MPType->castAs<MemberPointerType>(); 550234353Sdim const ValueDecl *MPD = MP.getMemberPointerDecl(); 551234353Sdim if (!MPD) 552234353Sdim return EmitNullMemberPointer(MPT); 553234353Sdim 554234353Sdim // Compute the this-adjustment. 555234353Sdim CharUnits ThisAdjustment = CharUnits::Zero(); 556234353Sdim ArrayRef<const CXXRecordDecl*> Path = MP.getMemberPointerPath(); 557234353Sdim bool DerivedMember = MP.isMemberPointerToDerivedMember(); 558234353Sdim const CXXRecordDecl *RD = cast<CXXRecordDecl>(MPD->getDeclContext()); 559234353Sdim for (unsigned I = 0, N = Path.size(); I != N; ++I) { 560234353Sdim const CXXRecordDecl *Base = RD; 561234353Sdim const CXXRecordDecl *Derived = Path[I]; 562234353Sdim if (DerivedMember) 563234353Sdim std::swap(Base, Derived); 564234353Sdim ThisAdjustment += 565234353Sdim getContext().getASTRecordLayout(Derived).getBaseClassOffset(Base); 566234353Sdim RD = Path[I]; 567234353Sdim } 568234353Sdim if (DerivedMember) 569234353Sdim ThisAdjustment = -ThisAdjustment; 570234353Sdim 571234353Sdim if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) 572234353Sdim return BuildMemberPointer(MD, ThisAdjustment); 573234353Sdim 574234353Sdim CharUnits FieldOffset = 575234353Sdim getContext().toCharUnitsFromBits(getContext().getFieldOffset(MPD)); 576234353Sdim return EmitMemberDataPointer(MPT, ThisAdjustment + FieldOffset); 577234353Sdim} 578234353Sdim 579212904Sdim/// The comparison algorithm is pretty easy: the member pointers are 580212904Sdim/// the same if they're either bitwise identical *or* both null. 581212904Sdim/// 582212904Sdim/// ARM is different here only because null-ness is more complicated. 583212904Sdimllvm::Value * 584212904SdimItaniumCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF, 585212904Sdim llvm::Value *L, 586212904Sdim llvm::Value *R, 587212904Sdim const MemberPointerType *MPT, 588212904Sdim bool Inequality) { 589212904Sdim CGBuilderTy &Builder = CGF.Builder; 590212904Sdim 591212904Sdim llvm::ICmpInst::Predicate Eq; 592212904Sdim llvm::Instruction::BinaryOps And, Or; 593212904Sdim if (Inequality) { 594212904Sdim Eq = llvm::ICmpInst::ICMP_NE; 595212904Sdim And = llvm::Instruction::Or; 596212904Sdim Or = llvm::Instruction::And; 597212904Sdim } else { 598212904Sdim Eq = llvm::ICmpInst::ICMP_EQ; 599212904Sdim And = llvm::Instruction::And; 600212904Sdim Or = llvm::Instruction::Or; 601212904Sdim } 602212904Sdim 603212904Sdim // Member data pointers are easy because there's a unique null 604212904Sdim // value, so it just comes down to bitwise equality. 605212904Sdim if (MPT->isMemberDataPointer()) 606212904Sdim return Builder.CreateICmp(Eq, L, R); 607212904Sdim 608212904Sdim // For member function pointers, the tautologies are more complex. 609212904Sdim // The Itanium tautology is: 610212904Sdim // (L == R) <==> (L.ptr == R.ptr && (L.ptr == 0 || L.adj == R.adj)) 611212904Sdim // The ARM tautology is: 612212904Sdim // (L == R) <==> (L.ptr == R.ptr && 613212904Sdim // (L.adj == R.adj || 614212904Sdim // (L.ptr == 0 && ((L.adj|R.adj) & 1) == 0))) 615212904Sdim // The inequality tautologies have exactly the same structure, except 616212904Sdim // applying De Morgan's laws. 617212904Sdim 618212904Sdim llvm::Value *LPtr = Builder.CreateExtractValue(L, 0, "lhs.memptr.ptr"); 619212904Sdim llvm::Value *RPtr = Builder.CreateExtractValue(R, 0, "rhs.memptr.ptr"); 620212904Sdim 621212904Sdim // This condition tests whether L.ptr == R.ptr. This must always be 622212904Sdim // true for equality to hold. 623212904Sdim llvm::Value *PtrEq = Builder.CreateICmp(Eq, LPtr, RPtr, "cmp.ptr"); 624212904Sdim 625212904Sdim // This condition, together with the assumption that L.ptr == R.ptr, 626212904Sdim // tests whether the pointers are both null. ARM imposes an extra 627212904Sdim // condition. 628212904Sdim llvm::Value *Zero = llvm::Constant::getNullValue(LPtr->getType()); 629212904Sdim llvm::Value *EqZero = Builder.CreateICmp(Eq, LPtr, Zero, "cmp.ptr.null"); 630212904Sdim 631212904Sdim // This condition tests whether L.adj == R.adj. If this isn't 632212904Sdim // true, the pointers are unequal unless they're both null. 633212904Sdim llvm::Value *LAdj = Builder.CreateExtractValue(L, 1, "lhs.memptr.adj"); 634212904Sdim llvm::Value *RAdj = Builder.CreateExtractValue(R, 1, "rhs.memptr.adj"); 635212904Sdim llvm::Value *AdjEq = Builder.CreateICmp(Eq, LAdj, RAdj, "cmp.adj"); 636212904Sdim 637212904Sdim // Null member function pointers on ARM clear the low bit of Adj, 638212904Sdim // so the zero condition has to check that neither low bit is set. 639212904Sdim if (IsARM) { 640212904Sdim llvm::Value *One = llvm::ConstantInt::get(LPtr->getType(), 1); 641212904Sdim 642212904Sdim // Compute (l.adj | r.adj) & 1 and test it against zero. 643212904Sdim llvm::Value *OrAdj = Builder.CreateOr(LAdj, RAdj, "or.adj"); 644212904Sdim llvm::Value *OrAdjAnd1 = Builder.CreateAnd(OrAdj, One); 645212904Sdim llvm::Value *OrAdjAnd1EqZero = Builder.CreateICmp(Eq, OrAdjAnd1, Zero, 646212904Sdim "cmp.or.adj"); 647212904Sdim EqZero = Builder.CreateBinOp(And, EqZero, OrAdjAnd1EqZero); 648212904Sdim } 649212904Sdim 650212904Sdim // Tie together all our conditions. 651212904Sdim llvm::Value *Result = Builder.CreateBinOp(Or, EqZero, AdjEq); 652212904Sdim Result = Builder.CreateBinOp(And, PtrEq, Result, 653212904Sdim Inequality ? "memptr.ne" : "memptr.eq"); 654212904Sdim return Result; 655212904Sdim} 656212904Sdim 657212904Sdimllvm::Value * 658212904SdimItaniumCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF, 659212904Sdim llvm::Value *MemPtr, 660212904Sdim const MemberPointerType *MPT) { 661212904Sdim CGBuilderTy &Builder = CGF.Builder; 662212904Sdim 663212904Sdim /// For member data pointers, this is just a check against -1. 664212904Sdim if (MPT->isMemberDataPointer()) { 665249423Sdim assert(MemPtr->getType() == CGM.PtrDiffTy); 666212904Sdim llvm::Value *NegativeOne = 667212904Sdim llvm::Constant::getAllOnesValue(MemPtr->getType()); 668212904Sdim return Builder.CreateICmpNE(MemPtr, NegativeOne, "memptr.tobool"); 669212904Sdim } 670212904Sdim 671221345Sdim // In Itanium, a member function pointer is not null if 'ptr' is not null. 672212904Sdim llvm::Value *Ptr = Builder.CreateExtractValue(MemPtr, 0, "memptr.ptr"); 673212904Sdim 674212904Sdim llvm::Constant *Zero = llvm::ConstantInt::get(Ptr->getType(), 0); 675212904Sdim llvm::Value *Result = Builder.CreateICmpNE(Ptr, Zero, "memptr.tobool"); 676212904Sdim 677221345Sdim // On ARM, a member function pointer is also non-null if the low bit of 'adj' 678221345Sdim // (the virtual bit) is set. 679212904Sdim if (IsARM) { 680212904Sdim llvm::Constant *One = llvm::ConstantInt::get(Ptr->getType(), 1); 681212904Sdim llvm::Value *Adj = Builder.CreateExtractValue(MemPtr, 1, "memptr.adj"); 682212904Sdim llvm::Value *VirtualBit = Builder.CreateAnd(Adj, One, "memptr.virtualbit"); 683221345Sdim llvm::Value *IsVirtual = Builder.CreateICmpNE(VirtualBit, Zero, 684221345Sdim "memptr.isvirtual"); 685221345Sdim Result = Builder.CreateOr(Result, IsVirtual); 686212904Sdim } 687212904Sdim 688212904Sdim return Result; 689212904Sdim} 690212904Sdim 691212904Sdim/// The Itanium ABI requires non-zero initialization only for data 692212904Sdim/// member pointers, for which '0' is a valid offset. 693212904Sdimbool ItaniumCXXABI::isZeroInitializable(const MemberPointerType *MPT) { 694212904Sdim return MPT->getPointeeType()->isFunctionType(); 695212904Sdim} 696212904Sdim 697243830Sdim/// The Itanium ABI always places an offset to the complete object 698243830Sdim/// at entry -2 in the vtable. 699243830Sdimllvm::Value *ItaniumCXXABI::adjustToCompleteObject(CodeGenFunction &CGF, 700243830Sdim llvm::Value *ptr, 701243830Sdim QualType type) { 702243830Sdim // Grab the vtable pointer as an intptr_t*. 703243830Sdim llvm::Value *vtable = CGF.GetVTablePtr(ptr, CGF.IntPtrTy->getPointerTo()); 704243830Sdim 705243830Sdim // Track back to entry -2 and pull out the offset there. 706243830Sdim llvm::Value *offsetPtr = 707243830Sdim CGF.Builder.CreateConstInBoundsGEP1_64(vtable, -2, "complete-offset.ptr"); 708243830Sdim llvm::LoadInst *offset = CGF.Builder.CreateLoad(offsetPtr); 709243830Sdim offset->setAlignment(CGF.PointerAlignInBytes); 710243830Sdim 711243830Sdim // Apply the offset. 712243830Sdim ptr = CGF.Builder.CreateBitCast(ptr, CGF.Int8PtrTy); 713243830Sdim return CGF.Builder.CreateInBoundsGEP(ptr, offset); 714243830Sdim} 715243830Sdim 716212904Sdim/// The generic ABI passes 'this', plus a VTT if it's initializing a 717212904Sdim/// base subobject. 718212904Sdimvoid ItaniumCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor, 719212904Sdim CXXCtorType Type, 720212904Sdim CanQualType &ResTy, 721226633Sdim SmallVectorImpl<CanQualType> &ArgTys) { 722212904Sdim ASTContext &Context = getContext(); 723212904Sdim 724212904Sdim // 'this' is already there. 725212904Sdim 726212904Sdim // Check if we need to add a VTT parameter (which has type void **). 727212904Sdim if (Type == Ctor_Base && Ctor->getParent()->getNumVBases() != 0) 728212904Sdim ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy)); 729212904Sdim} 730212904Sdim 731212904Sdim/// The ARM ABI does the same as the Itanium ABI, but returns 'this'. 732212904Sdimvoid ARMCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor, 733212904Sdim CXXCtorType Type, 734212904Sdim CanQualType &ResTy, 735226633Sdim SmallVectorImpl<CanQualType> &ArgTys) { 736212904Sdim ItaniumCXXABI::BuildConstructorSignature(Ctor, Type, ResTy, ArgTys); 737212904Sdim ResTy = ArgTys[0]; 738212904Sdim} 739212904Sdim 740212904Sdim/// The generic ABI passes 'this', plus a VTT if it's destroying a 741212904Sdim/// base subobject. 742212904Sdimvoid ItaniumCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor, 743212904Sdim CXXDtorType Type, 744212904Sdim CanQualType &ResTy, 745226633Sdim SmallVectorImpl<CanQualType> &ArgTys) { 746212904Sdim ASTContext &Context = getContext(); 747212904Sdim 748212904Sdim // 'this' is already there. 749212904Sdim 750212904Sdim // Check if we need to add a VTT parameter (which has type void **). 751212904Sdim if (Type == Dtor_Base && Dtor->getParent()->getNumVBases() != 0) 752212904Sdim ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy)); 753212904Sdim} 754212904Sdim 755212904Sdim/// The ARM ABI does the same as the Itanium ABI, but returns 'this' 756212904Sdim/// for non-deleting destructors. 757212904Sdimvoid ARMCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor, 758212904Sdim CXXDtorType Type, 759212904Sdim CanQualType &ResTy, 760226633Sdim SmallVectorImpl<CanQualType> &ArgTys) { 761212904Sdim ItaniumCXXABI::BuildDestructorSignature(Dtor, Type, ResTy, ArgTys); 762212904Sdim 763212904Sdim if (Type != Dtor_Deleting) 764212904Sdim ResTy = ArgTys[0]; 765212904Sdim} 766212904Sdim 767212904Sdimvoid ItaniumCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF, 768212904Sdim QualType &ResTy, 769212904Sdim FunctionArgList &Params) { 770212904Sdim /// Create the 'this' variable. 771212904Sdim BuildThisParam(CGF, Params); 772212904Sdim 773212904Sdim const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl()); 774212904Sdim assert(MD->isInstance()); 775212904Sdim 776212904Sdim // Check if we need a VTT parameter as well. 777212904Sdim if (CodeGenVTables::needsVTTParameter(CGF.CurGD)) { 778212904Sdim ASTContext &Context = getContext(); 779212904Sdim 780212904Sdim // FIXME: avoid the fake decl 781212904Sdim QualType T = Context.getPointerType(Context.VoidPtrTy); 782212904Sdim ImplicitParamDecl *VTTDecl 783212904Sdim = ImplicitParamDecl::Create(Context, 0, MD->getLocation(), 784212904Sdim &Context.Idents.get("vtt"), T); 785221345Sdim Params.push_back(VTTDecl); 786212904Sdim getVTTDecl(CGF) = VTTDecl; 787212904Sdim } 788212904Sdim} 789212904Sdim 790212904Sdimvoid ARMCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF, 791212904Sdim QualType &ResTy, 792212904Sdim FunctionArgList &Params) { 793212904Sdim ItaniumCXXABI::BuildInstanceFunctionParams(CGF, ResTy, Params); 794212904Sdim 795212904Sdim // Return 'this' from certain constructors and destructors. 796212904Sdim if (HasThisReturn(CGF.CurGD)) 797221345Sdim ResTy = Params[0]->getType(); 798212904Sdim} 799212904Sdim 800212904Sdimvoid ItaniumCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { 801212904Sdim /// Initialize the 'this' slot. 802212904Sdim EmitThisParam(CGF); 803212904Sdim 804212904Sdim /// Initialize the 'vtt' slot if needed. 805212904Sdim if (getVTTDecl(CGF)) { 806212904Sdim getVTTValue(CGF) 807212904Sdim = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(getVTTDecl(CGF)), 808212904Sdim "vtt"); 809212904Sdim } 810212904Sdim} 811212904Sdim 812212904Sdimvoid ARMCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { 813212904Sdim ItaniumCXXABI::EmitInstanceFunctionProlog(CGF); 814212904Sdim 815212904Sdim /// Initialize the return slot to 'this' at the start of the 816212904Sdim /// function. 817212904Sdim if (HasThisReturn(CGF.CurGD)) 818234353Sdim CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue); 819212904Sdim} 820212904Sdim 821249423Sdimllvm::Value *ItaniumCXXABI::EmitConstructorCall(CodeGenFunction &CGF, 822249423Sdim const CXXConstructorDecl *D, 823249423Sdim CXXCtorType Type, bool ForVirtualBase, 824249423Sdim bool Delegating, 825249423Sdim llvm::Value *This, 826249423Sdim CallExpr::const_arg_iterator ArgBeg, 827249423Sdim CallExpr::const_arg_iterator ArgEnd) { 828249423Sdim llvm::Value *VTT = CGF.GetVTTParameter(GlobalDecl(D, Type), ForVirtualBase, 829249423Sdim Delegating); 830249423Sdim QualType VTTTy = getContext().getPointerType(getContext().VoidPtrTy); 831249423Sdim llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Type); 832249423Sdim 833249423Sdim // FIXME: Provide a source location here. 834249423Sdim CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(), This, 835249423Sdim VTT, VTTTy, ArgBeg, ArgEnd); 836249423Sdim return Callee; 837249423Sdim} 838249423Sdim 839249423SdimRValue ItaniumCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF, 840249423Sdim const CXXDestructorDecl *Dtor, 841249423Sdim CXXDtorType DtorType, 842249423Sdim SourceLocation CallLoc, 843249423Sdim ReturnValueSlot ReturnValue, 844249423Sdim llvm::Value *This) { 845249423Sdim assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete); 846249423Sdim 847249423Sdim const CGFunctionInfo *FInfo 848249423Sdim = &CGM.getTypes().arrangeCXXDestructor(Dtor, DtorType); 849249423Sdim llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo); 850249423Sdim llvm::Value *Callee = CGF.BuildVirtualCall(Dtor, DtorType, This, Ty); 851249423Sdim 852249423Sdim return CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValue, This, 853249423Sdim /*ImplicitParam=*/0, QualType(), 0, 0); 854249423Sdim} 855249423Sdim 856212904Sdimvoid ARMCXXABI::EmitReturnFromThunk(CodeGenFunction &CGF, 857212904Sdim RValue RV, QualType ResultType) { 858212904Sdim if (!isa<CXXDestructorDecl>(CGF.CurGD.getDecl())) 859212904Sdim return ItaniumCXXABI::EmitReturnFromThunk(CGF, RV, ResultType); 860212904Sdim 861212904Sdim // Destructor thunks in the ARM ABI have indeterminate results. 862226633Sdim llvm::Type *T = 863212904Sdim cast<llvm::PointerType>(CGF.ReturnValue->getType())->getElementType(); 864212904Sdim RValue Undef = RValue::get(llvm::UndefValue::get(T)); 865212904Sdim return ItaniumCXXABI::EmitReturnFromThunk(CGF, Undef, ResultType); 866212904Sdim} 867212904Sdim 868212904Sdim/************************** Array allocation cookies **************************/ 869212904Sdim 870239462SdimCharUnits ItaniumCXXABI::getArrayCookieSizeImpl(QualType elementType) { 871239462Sdim // The array cookie is a size_t; pad that up to the element alignment. 872239462Sdim // The cookie is actually right-justified in that space. 873239462Sdim return std::max(CharUnits::fromQuantity(CGM.SizeSizeInBytes), 874239462Sdim CGM.getContext().getTypeAlignInChars(elementType)); 875218893Sdim} 876212904Sdim 877212904Sdimllvm::Value *ItaniumCXXABI::InitializeArrayCookie(CodeGenFunction &CGF, 878212904Sdim llvm::Value *NewPtr, 879212904Sdim llvm::Value *NumElements, 880218893Sdim const CXXNewExpr *expr, 881212904Sdim QualType ElementType) { 882239462Sdim assert(requiresArrayCookie(expr)); 883212904Sdim 884243830Sdim unsigned AS = NewPtr->getType()->getPointerAddressSpace(); 885212904Sdim 886212904Sdim ASTContext &Ctx = getContext(); 887212904Sdim QualType SizeTy = Ctx.getSizeType(); 888212904Sdim CharUnits SizeSize = Ctx.getTypeSizeInChars(SizeTy); 889212904Sdim 890212904Sdim // The size of the cookie. 891212904Sdim CharUnits CookieSize = 892212904Sdim std::max(SizeSize, Ctx.getTypeAlignInChars(ElementType)); 893239462Sdim assert(CookieSize == getArrayCookieSizeImpl(ElementType)); 894212904Sdim 895212904Sdim // Compute an offset to the cookie. 896212904Sdim llvm::Value *CookiePtr = NewPtr; 897212904Sdim CharUnits CookieOffset = CookieSize - SizeSize; 898212904Sdim if (!CookieOffset.isZero()) 899212904Sdim CookiePtr = CGF.Builder.CreateConstInBoundsGEP1_64(CookiePtr, 900212904Sdim CookieOffset.getQuantity()); 901212904Sdim 902212904Sdim // Write the number of elements into the appropriate slot. 903212904Sdim llvm::Value *NumElementsPtr 904212904Sdim = CGF.Builder.CreateBitCast(CookiePtr, 905212904Sdim CGF.ConvertType(SizeTy)->getPointerTo(AS)); 906212904Sdim CGF.Builder.CreateStore(NumElements, NumElementsPtr); 907212904Sdim 908212904Sdim // Finally, compute a pointer to the actual data buffer by skipping 909212904Sdim // over the cookie completely. 910212904Sdim return CGF.Builder.CreateConstInBoundsGEP1_64(NewPtr, 911212904Sdim CookieSize.getQuantity()); 912212904Sdim} 913212904Sdim 914239462Sdimllvm::Value *ItaniumCXXABI::readArrayCookieImpl(CodeGenFunction &CGF, 915239462Sdim llvm::Value *allocPtr, 916239462Sdim CharUnits cookieSize) { 917239462Sdim // The element size is right-justified in the cookie. 918239462Sdim llvm::Value *numElementsPtr = allocPtr; 919239462Sdim CharUnits numElementsOffset = 920239462Sdim cookieSize - CharUnits::fromQuantity(CGF.SizeSizeInBytes); 921239462Sdim if (!numElementsOffset.isZero()) 922239462Sdim numElementsPtr = 923239462Sdim CGF.Builder.CreateConstInBoundsGEP1_64(numElementsPtr, 924239462Sdim numElementsOffset.getQuantity()); 925212904Sdim 926243830Sdim unsigned AS = allocPtr->getType()->getPointerAddressSpace(); 927239462Sdim numElementsPtr = 928239462Sdim CGF.Builder.CreateBitCast(numElementsPtr, CGF.SizeTy->getPointerTo(AS)); 929239462Sdim return CGF.Builder.CreateLoad(numElementsPtr); 930212904Sdim} 931212904Sdim 932239462SdimCharUnits ARMCXXABI::getArrayCookieSizeImpl(QualType elementType) { 933249423Sdim // ARM says that the cookie is always: 934212904Sdim // struct array_cookie { 935212904Sdim // std::size_t element_size; // element_size != 0 936212904Sdim // std::size_t element_count; 937212904Sdim // }; 938249423Sdim // But the base ABI doesn't give anything an alignment greater than 939249423Sdim // 8, so we can dismiss this as typical ABI-author blindness to 940249423Sdim // actual language complexity and round up to the element alignment. 941249423Sdim return std::max(CharUnits::fromQuantity(2 * CGM.SizeSizeInBytes), 942249423Sdim CGM.getContext().getTypeAlignInChars(elementType)); 943212904Sdim} 944212904Sdim 945212904Sdimllvm::Value *ARMCXXABI::InitializeArrayCookie(CodeGenFunction &CGF, 946249423Sdim llvm::Value *newPtr, 947249423Sdim llvm::Value *numElements, 948218893Sdim const CXXNewExpr *expr, 949249423Sdim QualType elementType) { 950239462Sdim assert(requiresArrayCookie(expr)); 951212904Sdim 952249423Sdim // NewPtr is a char*, but we generalize to arbitrary addrspaces. 953249423Sdim unsigned AS = newPtr->getType()->getPointerAddressSpace(); 954212904Sdim 955212904Sdim // The cookie is always at the start of the buffer. 956249423Sdim llvm::Value *cookie = newPtr; 957212904Sdim 958212904Sdim // The first element is the element size. 959249423Sdim cookie = CGF.Builder.CreateBitCast(cookie, CGF.SizeTy->getPointerTo(AS)); 960249423Sdim llvm::Value *elementSize = llvm::ConstantInt::get(CGF.SizeTy, 961249423Sdim getContext().getTypeSizeInChars(elementType).getQuantity()); 962249423Sdim CGF.Builder.CreateStore(elementSize, cookie); 963212904Sdim 964212904Sdim // The second element is the element count. 965249423Sdim cookie = CGF.Builder.CreateConstInBoundsGEP1_32(cookie, 1); 966249423Sdim CGF.Builder.CreateStore(numElements, cookie); 967212904Sdim 968212904Sdim // Finally, compute a pointer to the actual data buffer by skipping 969212904Sdim // over the cookie completely. 970249423Sdim CharUnits cookieSize = ARMCXXABI::getArrayCookieSizeImpl(elementType); 971249423Sdim return CGF.Builder.CreateConstInBoundsGEP1_64(newPtr, 972249423Sdim cookieSize.getQuantity()); 973212904Sdim} 974212904Sdim 975239462Sdimllvm::Value *ARMCXXABI::readArrayCookieImpl(CodeGenFunction &CGF, 976239462Sdim llvm::Value *allocPtr, 977239462Sdim CharUnits cookieSize) { 978239462Sdim // The number of elements is at offset sizeof(size_t) relative to 979239462Sdim // the allocated pointer. 980239462Sdim llvm::Value *numElementsPtr 981239462Sdim = CGF.Builder.CreateConstInBoundsGEP1_64(allocPtr, CGF.SizeSizeInBytes); 982212904Sdim 983243830Sdim unsigned AS = allocPtr->getType()->getPointerAddressSpace(); 984239462Sdim numElementsPtr = 985239462Sdim CGF.Builder.CreateBitCast(numElementsPtr, CGF.SizeTy->getPointerTo(AS)); 986239462Sdim return CGF.Builder.CreateLoad(numElementsPtr); 987212904Sdim} 988212904Sdim 989218893Sdim/*********************** Static local initialization **************************/ 990218893Sdim 991218893Sdimstatic llvm::Constant *getGuardAcquireFn(CodeGenModule &CGM, 992224145Sdim llvm::PointerType *GuardPtrTy) { 993218893Sdim // int __cxa_guard_acquire(__guard *guard_object); 994226633Sdim llvm::FunctionType *FTy = 995218893Sdim llvm::FunctionType::get(CGM.getTypes().ConvertType(CGM.getContext().IntTy), 996226633Sdim GuardPtrTy, /*isVarArg=*/false); 997234353Sdim return CGM.CreateRuntimeFunction(FTy, "__cxa_guard_acquire", 998249423Sdim llvm::AttributeSet::get(CGM.getLLVMContext(), 999249423Sdim llvm::AttributeSet::FunctionIndex, 1000249423Sdim llvm::Attribute::NoUnwind)); 1001218893Sdim} 1002218893Sdim 1003218893Sdimstatic llvm::Constant *getGuardReleaseFn(CodeGenModule &CGM, 1004224145Sdim llvm::PointerType *GuardPtrTy) { 1005218893Sdim // void __cxa_guard_release(__guard *guard_object); 1006226633Sdim llvm::FunctionType *FTy = 1007234353Sdim llvm::FunctionType::get(CGM.VoidTy, GuardPtrTy, /*isVarArg=*/false); 1008234353Sdim return CGM.CreateRuntimeFunction(FTy, "__cxa_guard_release", 1009249423Sdim llvm::AttributeSet::get(CGM.getLLVMContext(), 1010249423Sdim llvm::AttributeSet::FunctionIndex, 1011249423Sdim llvm::Attribute::NoUnwind)); 1012218893Sdim} 1013218893Sdim 1014218893Sdimstatic llvm::Constant *getGuardAbortFn(CodeGenModule &CGM, 1015224145Sdim llvm::PointerType *GuardPtrTy) { 1016218893Sdim // void __cxa_guard_abort(__guard *guard_object); 1017226633Sdim llvm::FunctionType *FTy = 1018234353Sdim llvm::FunctionType::get(CGM.VoidTy, GuardPtrTy, /*isVarArg=*/false); 1019234353Sdim return CGM.CreateRuntimeFunction(FTy, "__cxa_guard_abort", 1020249423Sdim llvm::AttributeSet::get(CGM.getLLVMContext(), 1021249423Sdim llvm::AttributeSet::FunctionIndex, 1022249423Sdim llvm::Attribute::NoUnwind)); 1023218893Sdim} 1024218893Sdim 1025218893Sdimnamespace { 1026218893Sdim struct CallGuardAbort : EHScopeStack::Cleanup { 1027218893Sdim llvm::GlobalVariable *Guard; 1028218893Sdim CallGuardAbort(llvm::GlobalVariable *Guard) : Guard(Guard) {} 1029218893Sdim 1030224145Sdim void Emit(CodeGenFunction &CGF, Flags flags) { 1031249423Sdim CGF.EmitNounwindRuntimeCall(getGuardAbortFn(CGF.CGM, Guard->getType()), 1032249423Sdim Guard); 1033218893Sdim } 1034218893Sdim }; 1035218893Sdim} 1036218893Sdim 1037218893Sdim/// The ARM code here follows the Itanium code closely enough that we 1038218893Sdim/// just special-case it at particular places. 1039218893Sdimvoid ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF, 1040218893Sdim const VarDecl &D, 1041234353Sdim llvm::GlobalVariable *var, 1042234353Sdim bool shouldPerformInit) { 1043218893Sdim CGBuilderTy &Builder = CGF.Builder; 1044218893Sdim 1045218893Sdim // We only need to use thread-safe statics for local variables; 1046218893Sdim // global initialization is always single-threaded. 1047224145Sdim bool threadsafe = 1048234353Sdim (getContext().getLangOpts().ThreadsafeStatics && D.isLocalVarDecl()); 1049221345Sdim 1050221345Sdim // If we have a global variable with internal linkage and thread-safe statics 1051221345Sdim // are disabled, we can just let the guard variable be of type i8. 1052234353Sdim bool useInt8GuardVariable = !threadsafe && var->hasInternalLinkage(); 1053234353Sdim 1054234353Sdim llvm::IntegerType *guardTy; 1055224145Sdim if (useInt8GuardVariable) { 1056234353Sdim guardTy = CGF.Int8Ty; 1057224145Sdim } else { 1058249423Sdim // Guard variables are 64 bits in the generic ABI and size width on ARM 1059249423Sdim // (i.e. 32-bit on AArch32, 64-bit on AArch64). 1060249423Sdim guardTy = (IsARM ? CGF.SizeTy : CGF.Int64Ty); 1061221345Sdim } 1062234353Sdim llvm::PointerType *guardPtrTy = guardTy->getPointerTo(); 1063218893Sdim 1064234353Sdim // Create the guard variable if we don't already have it (as we 1065234353Sdim // might if we're double-emitting this function body). 1066234353Sdim llvm::GlobalVariable *guard = CGM.getStaticLocalDeclGuardAddress(&D); 1067234353Sdim if (!guard) { 1068234353Sdim // Mangle the name for the guard. 1069234353Sdim SmallString<256> guardName; 1070234353Sdim { 1071234353Sdim llvm::raw_svector_ostream out(guardName); 1072234353Sdim getMangleContext().mangleItaniumGuardVariable(&D, out); 1073234353Sdim out.flush(); 1074234353Sdim } 1075218893Sdim 1076234353Sdim // Create the guard variable with a zero-initializer. 1077234353Sdim // Just absorb linkage and visibility from the guarded variable. 1078234353Sdim guard = new llvm::GlobalVariable(CGM.getModule(), guardTy, 1079234353Sdim false, var->getLinkage(), 1080234353Sdim llvm::ConstantInt::get(guardTy, 0), 1081234353Sdim guardName.str()); 1082234353Sdim guard->setVisibility(var->getVisibility()); 1083218893Sdim 1084234353Sdim CGM.setStaticLocalDeclGuardAddress(&D, guard); 1085234353Sdim } 1086234353Sdim 1087218893Sdim // Test whether the variable has completed initialization. 1088234353Sdim llvm::Value *isInitialized; 1089218893Sdim 1090218893Sdim // ARM C++ ABI 3.2.3.1: 1091218893Sdim // To support the potential use of initialization guard variables 1092218893Sdim // as semaphores that are the target of ARM SWP and LDREX/STREX 1093218893Sdim // synchronizing instructions we define a static initialization 1094218893Sdim // guard variable to be a 4-byte aligned, 4- byte word with the 1095218893Sdim // following inline access protocol. 1096218893Sdim // #define INITIALIZED 1 1097218893Sdim // if ((obj_guard & INITIALIZED) != INITIALIZED) { 1098218893Sdim // if (__cxa_guard_acquire(&obj_guard)) 1099218893Sdim // ... 1100218893Sdim // } 1101224145Sdim if (IsARM && !useInt8GuardVariable) { 1102234353Sdim llvm::Value *V = Builder.CreateLoad(guard); 1103249423Sdim llvm::Value *Test1 = llvm::ConstantInt::get(guardTy, 1); 1104249423Sdim V = Builder.CreateAnd(V, Test1); 1105234353Sdim isInitialized = Builder.CreateIsNull(V, "guard.uninitialized"); 1106218893Sdim 1107218893Sdim // Itanium C++ ABI 3.3.2: 1108218893Sdim // The following is pseudo-code showing how these functions can be used: 1109218893Sdim // if (obj_guard.first_byte == 0) { 1110218893Sdim // if ( __cxa_guard_acquire (&obj_guard) ) { 1111218893Sdim // try { 1112218893Sdim // ... initialize the object ...; 1113218893Sdim // } catch (...) { 1114218893Sdim // __cxa_guard_abort (&obj_guard); 1115218893Sdim // throw; 1116218893Sdim // } 1117218893Sdim // ... queue object destructor with __cxa_atexit() ...; 1118218893Sdim // __cxa_guard_release (&obj_guard); 1119218893Sdim // } 1120218893Sdim // } 1121218893Sdim } else { 1122218893Sdim // Load the first byte of the guard variable. 1123226633Sdim llvm::LoadInst *LI = 1124234353Sdim Builder.CreateLoad(Builder.CreateBitCast(guard, CGM.Int8PtrTy)); 1125226633Sdim LI->setAlignment(1); 1126218893Sdim 1127226633Sdim // Itanium ABI: 1128226633Sdim // An implementation supporting thread-safety on multiprocessor 1129226633Sdim // systems must also guarantee that references to the initialized 1130226633Sdim // object do not occur before the load of the initialization flag. 1131226633Sdim // 1132226633Sdim // In LLVM, we do this by marking the load Acquire. 1133226633Sdim if (threadsafe) 1134226633Sdim LI->setAtomic(llvm::Acquire); 1135226633Sdim 1136234353Sdim isInitialized = Builder.CreateIsNull(LI, "guard.uninitialized"); 1137218893Sdim } 1138218893Sdim 1139218893Sdim llvm::BasicBlock *InitCheckBlock = CGF.createBasicBlock("init.check"); 1140218893Sdim llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end"); 1141218893Sdim 1142218893Sdim // Check if the first byte of the guard variable is zero. 1143234353Sdim Builder.CreateCondBr(isInitialized, InitCheckBlock, EndBlock); 1144218893Sdim 1145218893Sdim CGF.EmitBlock(InitCheckBlock); 1146218893Sdim 1147218893Sdim // Variables used when coping with thread-safe statics and exceptions. 1148224145Sdim if (threadsafe) { 1149218893Sdim // Call __cxa_guard_acquire. 1150218893Sdim llvm::Value *V 1151249423Sdim = CGF.EmitNounwindRuntimeCall(getGuardAcquireFn(CGM, guardPtrTy), guard); 1152218893Sdim 1153218893Sdim llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init"); 1154218893Sdim 1155218893Sdim Builder.CreateCondBr(Builder.CreateIsNotNull(V, "tobool"), 1156218893Sdim InitBlock, EndBlock); 1157218893Sdim 1158218893Sdim // Call __cxa_guard_abort along the exceptional edge. 1159234353Sdim CGF.EHStack.pushCleanup<CallGuardAbort>(EHCleanup, guard); 1160218893Sdim 1161218893Sdim CGF.EmitBlock(InitBlock); 1162218893Sdim } 1163218893Sdim 1164218893Sdim // Emit the initializer and add a global destructor if appropriate. 1165234353Sdim CGF.EmitCXXGlobalVarDeclInit(D, var, shouldPerformInit); 1166218893Sdim 1167224145Sdim if (threadsafe) { 1168218893Sdim // Pop the guard-abort cleanup if we pushed one. 1169218893Sdim CGF.PopCleanupBlock(); 1170218893Sdim 1171218893Sdim // Call __cxa_guard_release. This cannot throw. 1172249423Sdim CGF.EmitNounwindRuntimeCall(getGuardReleaseFn(CGM, guardPtrTy), guard); 1173218893Sdim } else { 1174234353Sdim Builder.CreateStore(llvm::ConstantInt::get(guardTy, 1), guard); 1175218893Sdim } 1176218893Sdim 1177218893Sdim CGF.EmitBlock(EndBlock); 1178218893Sdim} 1179239462Sdim 1180239462Sdim/// Register a global destructor using __cxa_atexit. 1181239462Sdimstatic void emitGlobalDtorWithCXAAtExit(CodeGenFunction &CGF, 1182239462Sdim llvm::Constant *dtor, 1183239462Sdim llvm::Constant *addr) { 1184239462Sdim // We're assuming that the destructor function is something we can 1185239462Sdim // reasonably call with the default CC. Go ahead and cast it to the 1186239462Sdim // right prototype. 1187239462Sdim llvm::Type *dtorTy = 1188239462Sdim llvm::FunctionType::get(CGF.VoidTy, CGF.Int8PtrTy, false)->getPointerTo(); 1189239462Sdim 1190239462Sdim // extern "C" int __cxa_atexit(void (*f)(void *), void *p, void *d); 1191239462Sdim llvm::Type *paramTys[] = { dtorTy, CGF.Int8PtrTy, CGF.Int8PtrTy }; 1192239462Sdim llvm::FunctionType *atexitTy = 1193239462Sdim llvm::FunctionType::get(CGF.IntTy, paramTys, false); 1194239462Sdim 1195239462Sdim // Fetch the actual function. 1196239462Sdim llvm::Constant *atexit = 1197239462Sdim CGF.CGM.CreateRuntimeFunction(atexitTy, "__cxa_atexit"); 1198239462Sdim if (llvm::Function *fn = dyn_cast<llvm::Function>(atexit)) 1199239462Sdim fn->setDoesNotThrow(); 1200239462Sdim 1201239462Sdim // Create a variable that binds the atexit to this shared object. 1202239462Sdim llvm::Constant *handle = 1203239462Sdim CGF.CGM.CreateRuntimeVariable(CGF.Int8Ty, "__dso_handle"); 1204239462Sdim 1205239462Sdim llvm::Value *args[] = { 1206239462Sdim llvm::ConstantExpr::getBitCast(dtor, dtorTy), 1207239462Sdim llvm::ConstantExpr::getBitCast(addr, CGF.Int8PtrTy), 1208239462Sdim handle 1209239462Sdim }; 1210249423Sdim CGF.EmitNounwindRuntimeCall(atexit, args); 1211239462Sdim} 1212239462Sdim 1213239462Sdim/// Register a global destructor as best as we know how. 1214239462Sdimvoid ItaniumCXXABI::registerGlobalDtor(CodeGenFunction &CGF, 1215239462Sdim llvm::Constant *dtor, 1216239462Sdim llvm::Constant *addr) { 1217239462Sdim // Use __cxa_atexit if available. 1218239462Sdim if (CGM.getCodeGenOpts().CXAAtExit) { 1219239462Sdim return emitGlobalDtorWithCXAAtExit(CGF, dtor, addr); 1220239462Sdim } 1221239462Sdim 1222239462Sdim // In Apple kexts, we want to add a global destructor entry. 1223239462Sdim // FIXME: shouldn't this be guarded by some variable? 1224243830Sdim if (CGM.getLangOpts().AppleKext) { 1225239462Sdim // Generate a global destructor entry. 1226239462Sdim return CGM.AddCXXDtorEntry(dtor, addr); 1227239462Sdim } 1228239462Sdim 1229239462Sdim CGF.registerGlobalDtorWithAtExit(dtor, addr); 1230239462Sdim} 1231