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Diffstat (limited to 'clang/lib/CodeGen/CGCXXABI.h')
| -rw-r--r-- | clang/lib/CodeGen/CGCXXABI.h | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGCXXABI.h b/clang/lib/CodeGen/CGCXXABI.h new file mode 100644 index 0000000..4e045f5 --- /dev/null +++ b/clang/lib/CodeGen/CGCXXABI.h @@ -0,0 +1,262 @@ +//===----- 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; + OwningPtr<MangleContext> MangleCtx; + + CGCXXABI(CodeGenModule &CGM) + : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {} + +protected: + ImplicitParamDecl *&getThisDecl(CodeGenFunction &CGF) { + return CGF.CXXABIThisDecl; + } + llvm::Value *&getThisValue(CodeGenFunction &CGF) { + return CGF.CXXABIThisValue; + } + + 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, base-to-derived, or bitcast member + /// pointer conversion. + virtual llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF, + const CastExpr *E, + llvm::Value *Src); + + /// Perform a derived-to-base, base-to-derived, or bitcast member + /// pointer conversion on a constant value. + virtual llvm::Constant *EmitMemberPointerConversion(const CastExpr *E, + llvm::Constant *Src); + + /// 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); + +protected: + /// A utility method for computing the offset required for the given + /// base-to-derived or derived-to-base member-pointer conversion. + /// Does not handle virtual conversions (in case we ever fully + /// support an ABI that allows this). Returns null if no adjustment + /// is required. + llvm::Constant *getMemberPointerAdjustment(const CastExpr *E); + +public: + /// 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. + /// If \p PerformInit is false, the initialization has been folded to a + /// constant and should not be performed. + /// + /// 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, bool PerformInit); + +}; + +/// Creates an instance of a C++ ABI class. +CGCXXABI *CreateARMCXXABI(CodeGenModule &CGM); +CGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM); +CGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM); + +} +} + +#endif |