| //===----- CGCXXABI.h - Interface to C++ ABIs -------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This provides an abstract class for C++ code generation. Concrete subclasses |
| // of this implement code generation for specific C++ ABIs. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef CLANG_CODEGEN_CXXABI_H |
| #define CLANG_CODEGEN_CXXABI_H |
| |
| #include "clang/Basic/LLVM.h" |
| |
| #include "CodeGenFunction.h" |
| |
| namespace llvm { |
| class Constant; |
| class Type; |
| class Value; |
| } |
| |
| namespace clang { |
| class CastExpr; |
| class CXXConstructorDecl; |
| class CXXDestructorDecl; |
| class CXXMethodDecl; |
| class CXXRecordDecl; |
| class FieldDecl; |
| class MangleContext; |
| |
| namespace CodeGen { |
| class CodeGenFunction; |
| class CodeGenModule; |
| |
| /// Implements C++ ABI-specific code generation functions. |
| class CGCXXABI { |
| protected: |
| CodeGenModule &CGM; |
| llvm::OwningPtr<MangleContext> MangleCtx; |
| |
| CGCXXABI(CodeGenModule &CGM) |
| : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {} |
| |
| protected: |
| ImplicitParamDecl *&getThisDecl(CodeGenFunction &CGF) { |
| return CGF.CXXThisDecl; |
| } |
| llvm::Value *&getThisValue(CodeGenFunction &CGF) { |
| return CGF.CXXThisValue; |
| } |
| |
| ImplicitParamDecl *&getVTTDecl(CodeGenFunction &CGF) { |
| return CGF.CXXVTTDecl; |
| } |
| llvm::Value *&getVTTValue(CodeGenFunction &CGF) { |
| return CGF.CXXVTTValue; |
| } |
| |
| /// Build a parameter variable suitable for 'this'. |
| void BuildThisParam(CodeGenFunction &CGF, FunctionArgList &Params); |
| |
| /// Perform prolog initialization of the parameter variable suitable |
| /// for 'this' emitted by BuildThisParam. |
| void EmitThisParam(CodeGenFunction &CGF); |
| |
| ASTContext &getContext() const { return CGM.getContext(); } |
| |
| public: |
| |
| virtual ~CGCXXABI(); |
| |
| /// Gets the mangle context. |
| MangleContext &getMangleContext() { |
| return *MangleCtx; |
| } |
| |
| /// Find the LLVM type used to represent the given member pointer |
| /// type. |
| virtual llvm::Type * |
| ConvertMemberPointerType(const MemberPointerType *MPT); |
| |
| /// Load a member function from an object and a member function |
| /// pointer. Apply the this-adjustment and set 'This' to the |
| /// adjusted value. |
| virtual llvm::Value * |
| EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, |
| llvm::Value *&This, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| /// Calculate an l-value from an object and a data member pointer. |
| virtual llvm::Value *EmitMemberDataPointerAddress(CodeGenFunction &CGF, |
| llvm::Value *Base, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| /// Perform a derived-to-base or base-to-derived member pointer |
| /// conversion. |
| virtual llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF, |
| const CastExpr *E, |
| llvm::Value *Src); |
| |
| /// Perform a derived-to-base or base-to-derived member pointer |
| /// conversion on a constant member pointer. |
| virtual llvm::Constant *EmitMemberPointerConversion(llvm::Constant *C, |
| const CastExpr *E); |
| |
| /// Return true if the given member pointer can be zero-initialized |
| /// (in the C++ sense) with an LLVM zeroinitializer. |
| virtual bool isZeroInitializable(const MemberPointerType *MPT); |
| |
| /// Create a null member pointer of the given type. |
| virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT); |
| |
| /// Create a member pointer for the given method. |
| virtual llvm::Constant *EmitMemberPointer(const CXXMethodDecl *MD); |
| |
| /// Create a member pointer for the given field. |
| virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT, |
| CharUnits offset); |
| |
| /// Create a member pointer for the given member pointer constant. |
| virtual llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT); |
| |
| /// Emit a comparison between two member pointers. Returns an i1. |
| virtual llvm::Value * |
| EmitMemberPointerComparison(CodeGenFunction &CGF, |
| llvm::Value *L, |
| llvm::Value *R, |
| const MemberPointerType *MPT, |
| bool Inequality); |
| |
| /// Determine if a member pointer is non-null. Returns an i1. |
| virtual llvm::Value * |
| EmitMemberPointerIsNotNull(CodeGenFunction &CGF, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| /// Build the signature of the given constructor variant by adding |
| /// any required parameters. For convenience, ResTy has been |
| /// initialized to 'void', and ArgTys has been initialized with the |
| /// type of 'this' (although this may be changed by the ABI) and |
| /// will have the formal parameters added to it afterwards. |
| /// |
| /// If there are ever any ABIs where the implicit parameters are |
| /// intermixed with the formal parameters, we can address those |
| /// then. |
| virtual void BuildConstructorSignature(const CXXConstructorDecl *Ctor, |
| CXXCtorType T, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys) = 0; |
| |
| /// Build the signature of the given destructor variant by adding |
| /// any required parameters. For convenience, ResTy has been |
| /// initialized to 'void' and ArgTys has been initialized with the |
| /// type of 'this' (although this may be changed by the ABI). |
| virtual void BuildDestructorSignature(const CXXDestructorDecl *Dtor, |
| CXXDtorType T, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys) = 0; |
| |
| /// Build the ABI-specific portion of the parameter list for a |
| /// function. This generally involves a 'this' parameter and |
| /// possibly some extra data for constructors and destructors. |
| /// |
| /// ABIs may also choose to override the return type, which has been |
| /// initialized with the formal return type of the function. |
| virtual void BuildInstanceFunctionParams(CodeGenFunction &CGF, |
| QualType &ResTy, |
| FunctionArgList &Params) = 0; |
| |
| /// Emit the ABI-specific prolog for the function. |
| virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0; |
| |
| virtual void EmitReturnFromThunk(CodeGenFunction &CGF, |
| RValue RV, QualType ResultType); |
| |
| /**************************** Array cookies ******************************/ |
| |
| /// Returns the extra size required in order to store the array |
| /// cookie for the given type. May return 0 to indicate that no |
| /// array cookie is required. |
| /// |
| /// Several cases are filtered out before this method is called: |
| /// - non-array allocations never need a cookie |
| /// - calls to ::operator new(size_t, void*) never need a cookie |
| /// |
| /// \param ElementType - the allocated type of the expression, |
| /// i.e. the pointee type of the expression result type |
| virtual CharUnits GetArrayCookieSize(const CXXNewExpr *expr); |
| |
| /// Initialize the array cookie for the given allocation. |
| /// |
| /// \param NewPtr - a char* which is the presumed-non-null |
| /// return value of the allocation function |
| /// \param NumElements - the computed number of elements, |
| /// potentially collapsed from the multidimensional array case |
| /// \param ElementType - the base element allocated type, |
| /// i.e. the allocated type after stripping all array types |
| virtual llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF, |
| llvm::Value *NewPtr, |
| llvm::Value *NumElements, |
| const CXXNewExpr *expr, |
| QualType ElementType); |
| |
| /// Reads the array cookie associated with the given pointer, |
| /// if it has one. |
| /// |
| /// \param Ptr - a pointer to the first element in the array |
| /// \param ElementType - the base element type of elements of the array |
| /// \param NumElements - an out parameter which will be initialized |
| /// with the number of elements allocated, or zero if there is no |
| /// cookie |
| /// \param AllocPtr - an out parameter which will be initialized |
| /// with a char* pointing to the address returned by the allocation |
| /// function |
| /// \param CookieSize - an out parameter which will be initialized |
| /// with the size of the cookie, or zero if there is no cookie |
| virtual void ReadArrayCookie(CodeGenFunction &CGF, llvm::Value *Ptr, |
| const CXXDeleteExpr *expr, |
| QualType ElementType, llvm::Value *&NumElements, |
| llvm::Value *&AllocPtr, CharUnits &CookieSize); |
| |
| /*************************** Static local guards ****************************/ |
| |
| /// Emits the guarded initializer and destructor setup for the given |
| /// variable, given that it couldn't be emitted as a constant. |
| /// |
| /// The variable may be: |
| /// - a static local variable |
| /// - a static data member of a class template instantiation |
| virtual void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, |
| llvm::GlobalVariable *DeclPtr); |
| |
| }; |
| |
| /// Creates an instance of a C++ ABI class. |
| CGCXXABI *CreateARMCXXABI(CodeGenModule &CGM); |
| CGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM); |
| CGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM); |
| |
| } |
| } |
| |
| #endif |