1208600Srdivacky//===----- CGCXXABI.h - Interface to C++ ABIs -------------------*- C++ -*-===// 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// 10208600Srdivacky// This provides an abstract class for C++ code generation. Concrete subclasses 11208600Srdivacky// of this implement code generation for specific C++ ABIs. 12208600Srdivacky// 13208600Srdivacky//===----------------------------------------------------------------------===// 14208600Srdivacky 15208600Srdivacky#ifndef CLANG_CODEGEN_CXXABI_H 16208600Srdivacky#define CLANG_CODEGEN_CXXABI_H 17208600Srdivacky 18249423Sdim#include "CodeGenFunction.h" 19226633Sdim#include "clang/Basic/LLVM.h" 20226633Sdim 21212904Sdimnamespace llvm { 22212904Sdim class Constant; 23212904Sdim class Type; 24212904Sdim class Value; 25212904Sdim} 26212904Sdim 27208600Srdivackynamespace clang { 28212904Sdim class CastExpr; 29212904Sdim class CXXConstructorDecl; 30212904Sdim class CXXDestructorDecl; 31212904Sdim class CXXMethodDecl; 32212904Sdim class CXXRecordDecl; 33212904Sdim class FieldDecl; 34218893Sdim class MangleContext; 35212904Sdim 36208600Srdivackynamespace CodeGen { 37212904Sdim class CodeGenFunction; 38208600Srdivacky class CodeGenModule; 39208600Srdivacky 40239462Sdim/// \brief Implements C++ ABI-specific code generation functions. 41212904Sdimclass CGCXXABI { 42212904Sdimprotected: 43212904Sdim CodeGenModule &CGM; 44234353Sdim OwningPtr<MangleContext> MangleCtx; 45212904Sdim 46218893Sdim CGCXXABI(CodeGenModule &CGM) 47218893Sdim : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {} 48212904Sdim 49212904Sdimprotected: 50212904Sdim ImplicitParamDecl *&getThisDecl(CodeGenFunction &CGF) { 51234353Sdim return CGF.CXXABIThisDecl; 52212904Sdim } 53212904Sdim llvm::Value *&getThisValue(CodeGenFunction &CGF) { 54234353Sdim return CGF.CXXABIThisValue; 55212904Sdim } 56212904Sdim 57249423Sdim /// Issue a diagnostic about unsupported features in the ABI. 58249423Sdim void ErrorUnsupportedABI(CodeGenFunction &CGF, StringRef S); 59249423Sdim 60249423Sdim /// Get a null value for unsupported member pointers. 61249423Sdim llvm::Constant *GetBogusMemberPointer(QualType T); 62249423Sdim 63249423Sdim // FIXME: Every place that calls getVTT{Decl,Value} is something 64249423Sdim // that needs to be abstracted properly. 65212904Sdim ImplicitParamDecl *&getVTTDecl(CodeGenFunction &CGF) { 66249423Sdim return CGF.CXXStructorImplicitParamDecl; 67212904Sdim } 68212904Sdim llvm::Value *&getVTTValue(CodeGenFunction &CGF) { 69249423Sdim return CGF.CXXStructorImplicitParamValue; 70212904Sdim } 71212904Sdim 72249423Sdim ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) { 73249423Sdim return CGF.CXXStructorImplicitParamDecl; 74249423Sdim } 75249423Sdim llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) { 76249423Sdim return CGF.CXXStructorImplicitParamValue; 77249423Sdim } 78249423Sdim 79212904Sdim /// Build a parameter variable suitable for 'this'. 80212904Sdim void BuildThisParam(CodeGenFunction &CGF, FunctionArgList &Params); 81212904Sdim 82212904Sdim /// Perform prolog initialization of the parameter variable suitable 83212904Sdim /// for 'this' emitted by BuildThisParam. 84212904Sdim void EmitThisParam(CodeGenFunction &CGF); 85212904Sdim 86212904Sdim ASTContext &getContext() const { return CGM.getContext(); } 87212904Sdim 88239462Sdim virtual bool requiresArrayCookie(const CXXDeleteExpr *E, QualType eltType); 89239462Sdim virtual bool requiresArrayCookie(const CXXNewExpr *E); 90239462Sdim 91208600Srdivackypublic: 92208600Srdivacky 93212904Sdim virtual ~CGCXXABI(); 94212904Sdim 95208600Srdivacky /// Gets the mangle context. 96218893Sdim MangleContext &getMangleContext() { 97218893Sdim return *MangleCtx; 98218893Sdim } 99212904Sdim 100249423Sdim /// Returns true if the given instance method is one of the 101249423Sdim /// kinds that the ABI says returns 'this'. 102249423Sdim virtual bool HasThisReturn(GlobalDecl GD) const { return false; } 103249423Sdim 104251662Sdim /// Returns true if the given record type should be returned indirectly. 105251662Sdim virtual bool isReturnTypeIndirect(const CXXRecordDecl *RD) const = 0; 106251662Sdim 107251662Sdim /// Specify how one should pass an argument of a record type. 108251662Sdim enum RecordArgABI { 109251662Sdim /// Pass it using the normal C aggregate rules for the ABI, potentially 110251662Sdim /// introducing extra copies and passing some or all of it in registers. 111251662Sdim RAA_Default = 0, 112251662Sdim 113251662Sdim /// Pass it on the stack using its defined layout. The argument must be 114251662Sdim /// evaluated directly into the correct stack position in the arguments area, 115251662Sdim /// and the call machinery must not move it or introduce extra copies. 116251662Sdim RAA_DirectInMemory, 117251662Sdim 118251662Sdim /// Pass it as a pointer to temporary memory. 119251662Sdim RAA_Indirect 120251662Sdim }; 121251662Sdim 122251662Sdim /// Returns how an argument of the given record type should be passed. 123251662Sdim virtual RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const = 0; 124251662Sdim 125212904Sdim /// Find the LLVM type used to represent the given member pointer 126212904Sdim /// type. 127224145Sdim virtual llvm::Type * 128212904Sdim ConvertMemberPointerType(const MemberPointerType *MPT); 129212904Sdim 130212904Sdim /// Load a member function from an object and a member function 131212904Sdim /// pointer. Apply the this-adjustment and set 'This' to the 132212904Sdim /// adjusted value. 133212904Sdim virtual llvm::Value * 134212904Sdim EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, 135212904Sdim llvm::Value *&This, 136212904Sdim llvm::Value *MemPtr, 137212904Sdim const MemberPointerType *MPT); 138212904Sdim 139212904Sdim /// Calculate an l-value from an object and a data member pointer. 140212904Sdim virtual llvm::Value *EmitMemberDataPointerAddress(CodeGenFunction &CGF, 141212904Sdim llvm::Value *Base, 142212904Sdim llvm::Value *MemPtr, 143212904Sdim const MemberPointerType *MPT); 144212904Sdim 145234353Sdim /// Perform a derived-to-base, base-to-derived, or bitcast member 146234353Sdim /// pointer conversion. 147212904Sdim virtual llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF, 148212904Sdim const CastExpr *E, 149212904Sdim llvm::Value *Src); 150212904Sdim 151234353Sdim /// Perform a derived-to-base, base-to-derived, or bitcast member 152234353Sdim /// pointer conversion on a constant value. 153234353Sdim virtual llvm::Constant *EmitMemberPointerConversion(const CastExpr *E, 154234353Sdim llvm::Constant *Src); 155212904Sdim 156212904Sdim /// Return true if the given member pointer can be zero-initialized 157212904Sdim /// (in the C++ sense) with an LLVM zeroinitializer. 158212904Sdim virtual bool isZeroInitializable(const MemberPointerType *MPT); 159212904Sdim 160212904Sdim /// Create a null member pointer of the given type. 161212904Sdim virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT); 162212904Sdim 163212904Sdim /// Create a member pointer for the given method. 164212904Sdim virtual llvm::Constant *EmitMemberPointer(const CXXMethodDecl *MD); 165212904Sdim 166212904Sdim /// Create a member pointer for the given field. 167218893Sdim virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT, 168218893Sdim CharUnits offset); 169212904Sdim 170234353Sdim /// Create a member pointer for the given member pointer constant. 171234353Sdim virtual llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT); 172234353Sdim 173212904Sdim /// Emit a comparison between two member pointers. Returns an i1. 174212904Sdim virtual llvm::Value * 175212904Sdim EmitMemberPointerComparison(CodeGenFunction &CGF, 176212904Sdim llvm::Value *L, 177212904Sdim llvm::Value *R, 178212904Sdim const MemberPointerType *MPT, 179212904Sdim bool Inequality); 180212904Sdim 181212904Sdim /// Determine if a member pointer is non-null. Returns an i1. 182212904Sdim virtual llvm::Value * 183212904Sdim EmitMemberPointerIsNotNull(CodeGenFunction &CGF, 184212904Sdim llvm::Value *MemPtr, 185212904Sdim const MemberPointerType *MPT); 186212904Sdim 187234353Sdimprotected: 188234353Sdim /// A utility method for computing the offset required for the given 189234353Sdim /// base-to-derived or derived-to-base member-pointer conversion. 190234353Sdim /// Does not handle virtual conversions (in case we ever fully 191234353Sdim /// support an ABI that allows this). Returns null if no adjustment 192234353Sdim /// is required. 193234353Sdim llvm::Constant *getMemberPointerAdjustment(const CastExpr *E); 194234353Sdim 195234353Sdimpublic: 196243830Sdim /// Adjust the given non-null pointer to an object of polymorphic 197243830Sdim /// type to point to the complete object. 198243830Sdim /// 199243830Sdim /// The IR type of the result should be a pointer but is otherwise 200243830Sdim /// irrelevant. 201243830Sdim virtual llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, 202243830Sdim llvm::Value *ptr, 203243830Sdim QualType type) = 0; 204243830Sdim 205212904Sdim /// Build the signature of the given constructor variant by adding 206212904Sdim /// any required parameters. For convenience, ResTy has been 207212904Sdim /// initialized to 'void', and ArgTys has been initialized with the 208212904Sdim /// type of 'this' (although this may be changed by the ABI) and 209212904Sdim /// will have the formal parameters added to it afterwards. 210212904Sdim /// 211212904Sdim /// If there are ever any ABIs where the implicit parameters are 212212904Sdim /// intermixed with the formal parameters, we can address those 213212904Sdim /// then. 214212904Sdim virtual void BuildConstructorSignature(const CXXConstructorDecl *Ctor, 215212904Sdim CXXCtorType T, 216212904Sdim CanQualType &ResTy, 217226633Sdim SmallVectorImpl<CanQualType> &ArgTys) = 0; 218212904Sdim 219249423Sdim virtual llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF); 220249423Sdim 221212904Sdim /// Build the signature of the given destructor variant by adding 222212904Sdim /// any required parameters. For convenience, ResTy has been 223212904Sdim /// initialized to 'void' and ArgTys has been initialized with the 224212904Sdim /// type of 'this' (although this may be changed by the ABI). 225212904Sdim virtual void BuildDestructorSignature(const CXXDestructorDecl *Dtor, 226212904Sdim CXXDtorType T, 227212904Sdim CanQualType &ResTy, 228226633Sdim SmallVectorImpl<CanQualType> &ArgTys) = 0; 229212904Sdim 230212904Sdim /// Build the ABI-specific portion of the parameter list for a 231212904Sdim /// function. This generally involves a 'this' parameter and 232212904Sdim /// possibly some extra data for constructors and destructors. 233212904Sdim /// 234212904Sdim /// ABIs may also choose to override the return type, which has been 235212904Sdim /// initialized with the formal return type of the function. 236212904Sdim virtual void BuildInstanceFunctionParams(CodeGenFunction &CGF, 237212904Sdim QualType &ResTy, 238212904Sdim FunctionArgList &Params) = 0; 239212904Sdim 240212904Sdim /// Emit the ABI-specific prolog for the function. 241212904Sdim virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0; 242212904Sdim 243249423Sdim /// Emit the constructor call. Return the function that is called. 244249423Sdim virtual llvm::Value *EmitConstructorCall(CodeGenFunction &CGF, 245249423Sdim const CXXConstructorDecl *D, 246249423Sdim CXXCtorType Type, bool ForVirtualBase, 247249423Sdim bool Delegating, 248249423Sdim llvm::Value *This, 249249423Sdim CallExpr::const_arg_iterator ArgBeg, 250249423Sdim CallExpr::const_arg_iterator ArgEnd) = 0; 251249423Sdim 252249423Sdim /// Emit the ABI-specific virtual destructor call. 253249423Sdim virtual RValue EmitVirtualDestructorCall(CodeGenFunction &CGF, 254249423Sdim const CXXDestructorDecl *Dtor, 255249423Sdim CXXDtorType DtorType, 256249423Sdim SourceLocation CallLoc, 257249423Sdim ReturnValueSlot ReturnValue, 258249423Sdim llvm::Value *This) = 0; 259249423Sdim 260212904Sdim virtual void EmitReturnFromThunk(CodeGenFunction &CGF, 261212904Sdim RValue RV, QualType ResultType); 262212904Sdim 263239462Sdim /// Gets the pure virtual member call function. 264239462Sdim virtual StringRef GetPureVirtualCallName() = 0; 265239462Sdim 266243830Sdim /// Gets the deleted virtual member call name. 267243830Sdim virtual StringRef GetDeletedVirtualCallName() = 0; 268243830Sdim 269212904Sdim /**************************** Array cookies ******************************/ 270212904Sdim 271212904Sdim /// Returns the extra size required in order to store the array 272239462Sdim /// cookie for the given new-expression. May return 0 to indicate that no 273212904Sdim /// array cookie is required. 274212904Sdim /// 275212904Sdim /// Several cases are filtered out before this method is called: 276212904Sdim /// - non-array allocations never need a cookie 277239462Sdim /// - calls to \::operator new(size_t, void*) never need a cookie 278212904Sdim /// 279239462Sdim /// \param expr - the new-expression being allocated. 280218893Sdim virtual CharUnits GetArrayCookieSize(const CXXNewExpr *expr); 281212904Sdim 282212904Sdim /// Initialize the array cookie for the given allocation. 283212904Sdim /// 284212904Sdim /// \param NewPtr - a char* which is the presumed-non-null 285212904Sdim /// return value of the allocation function 286212904Sdim /// \param NumElements - the computed number of elements, 287239462Sdim /// potentially collapsed from the multidimensional array case; 288239462Sdim /// always a size_t 289212904Sdim /// \param ElementType - the base element allocated type, 290212904Sdim /// i.e. the allocated type after stripping all array types 291212904Sdim virtual llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF, 292212904Sdim llvm::Value *NewPtr, 293212904Sdim llvm::Value *NumElements, 294218893Sdim const CXXNewExpr *expr, 295212904Sdim QualType ElementType); 296212904Sdim 297212904Sdim /// Reads the array cookie associated with the given pointer, 298212904Sdim /// if it has one. 299212904Sdim /// 300212904Sdim /// \param Ptr - a pointer to the first element in the array 301212904Sdim /// \param ElementType - the base element type of elements of the array 302212904Sdim /// \param NumElements - an out parameter which will be initialized 303212904Sdim /// with the number of elements allocated, or zero if there is no 304212904Sdim /// cookie 305212904Sdim /// \param AllocPtr - an out parameter which will be initialized 306212904Sdim /// with a char* pointing to the address returned by the allocation 307212904Sdim /// function 308212904Sdim /// \param CookieSize - an out parameter which will be initialized 309212904Sdim /// with the size of the cookie, or zero if there is no cookie 310212904Sdim virtual void ReadArrayCookie(CodeGenFunction &CGF, llvm::Value *Ptr, 311218893Sdim const CXXDeleteExpr *expr, 312212904Sdim QualType ElementType, llvm::Value *&NumElements, 313212904Sdim llvm::Value *&AllocPtr, CharUnits &CookieSize); 314212904Sdim 315239462Sdimprotected: 316239462Sdim /// Returns the extra size required in order to store the array 317239462Sdim /// cookie for the given type. Assumes that an array cookie is 318239462Sdim /// required. 319239462Sdim virtual CharUnits getArrayCookieSizeImpl(QualType elementType); 320239462Sdim 321239462Sdim /// Reads the array cookie for an allocation which is known to have one. 322239462Sdim /// This is called by the standard implementation of ReadArrayCookie. 323239462Sdim /// 324239462Sdim /// \param ptr - a pointer to the allocation made for an array, as a char* 325239462Sdim /// \param cookieSize - the computed cookie size of an array 326239462Sdim /// 327239462Sdim /// Other parameters are as above. 328239462Sdim /// 329239462Sdim /// \return a size_t 330239462Sdim virtual llvm::Value *readArrayCookieImpl(CodeGenFunction &IGF, 331239462Sdim llvm::Value *ptr, 332239462Sdim CharUnits cookieSize); 333239462Sdim 334239462Sdimpublic: 335239462Sdim 336218893Sdim /*************************** Static local guards ****************************/ 337218893Sdim 338218893Sdim /// Emits the guarded initializer and destructor setup for the given 339218893Sdim /// variable, given that it couldn't be emitted as a constant. 340234353Sdim /// If \p PerformInit is false, the initialization has been folded to a 341234353Sdim /// constant and should not be performed. 342218893Sdim /// 343218893Sdim /// The variable may be: 344218893Sdim /// - a static local variable 345218893Sdim /// - a static data member of a class template instantiation 346218893Sdim virtual void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, 347234353Sdim llvm::GlobalVariable *DeclPtr, bool PerformInit); 348218893Sdim 349239462Sdim /// Emit code to force the execution of a destructor during global 350239462Sdim /// teardown. The default implementation of this uses atexit. 351239462Sdim /// 352239462Sdim /// \param dtor - a function taking a single pointer argument 353239462Sdim /// \param addr - a pointer to pass to the destructor function. 354251662Sdim virtual void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D, 355251662Sdim llvm::Constant *dtor, llvm::Constant *addr); 356251662Sdim 357251662Sdim /*************************** thread_local initialization ********************/ 358251662Sdim 359251662Sdim /// Emits ABI-required functions necessary to initialize thread_local 360251662Sdim /// variables in this translation unit. 361251662Sdim /// 362251662Sdim /// \param Decls The thread_local declarations in this translation unit. 363251662Sdim /// \param InitFunc If this translation unit contains any non-constant 364251662Sdim /// initialization or non-trivial destruction for thread_local 365251662Sdim /// variables, a function to perform the initialization. Otherwise, 0. 366251662Sdim virtual void EmitThreadLocalInitFuncs( 367251662Sdim llvm::ArrayRef<std::pair<const VarDecl *, llvm::GlobalVariable *> > Decls, 368251662Sdim llvm::Function *InitFunc); 369251662Sdim 370251662Sdim /// Emit a reference to a non-local thread_local variable (including 371251662Sdim /// triggering the initialization of all thread_local variables in its 372251662Sdim /// translation unit). 373251662Sdim virtual LValue EmitThreadLocalDeclRefExpr(CodeGenFunction &CGF, 374251662Sdim const DeclRefExpr *DRE); 375249423Sdim}; 376239462Sdim 377249423Sdim// Create an instance of a C++ ABI class: 378239462Sdim 379249423Sdim/// Creates an Itanium-family ABI. 380249423SdimCGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM); 381208600Srdivacky 382249423Sdim/// Creates a Microsoft-family ABI. 383212904SdimCGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM); 384212904Sdim 385208600Srdivacky} 386208600Srdivacky} 387208600Srdivacky 388208600Srdivacky#endif 389