//
//===----------------------------------------------------------------------===//
-#ifndef CLANG_CODEGEN_CXXABI_H
-#define CLANG_CODEGEN_CXXABI_H
+#ifndef LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
+#define LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
+
+#include "CodeGenFunction.h"
+#include "clang/Basic/LLVM.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 CodeGenModule;
- class MangleContext;
+class CodeGenFunction;
+class CodeGenModule;
-/// Implements C++ ABI-specific code generation functions.
+/// \brief Implements C++ ABI-specific code generation functions.
class CGCXXABI {
+protected:
+ CodeGenModule &CGM;
+ std::unique_ptr<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;
+ }
+
+ /// Issue a diagnostic about unsupported features in the ABI.
+ void ErrorUnsupportedABI(CodeGenFunction &CGF, StringRef S);
+
+ /// Get a null value for unsupported member pointers.
+ llvm::Constant *GetBogusMemberPointer(QualType T);
+
+ ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) {
+ return CGF.CXXStructorImplicitParamDecl;
+ }
+ llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) {
+ return CGF.CXXStructorImplicitParamValue;
+ }
+
+ /// Perform prolog initialization of the parameter variable suitable
+ /// for 'this' emitted by buildThisParam.
+ void EmitThisParam(CodeGenFunction &CGF);
+
+ ASTContext &getContext() const { return CGM.getContext(); }
+
+ virtual bool requiresArrayCookie(const CXXDeleteExpr *E, QualType eltType);
+ virtual bool requiresArrayCookie(const CXXNewExpr *E);
+
public:
+
virtual ~CGCXXABI();
/// Gets the mangle context.
- virtual MangleContext &getMangleContext() = 0;
+ MangleContext &getMangleContext() {
+ return *MangleCtx;
+ }
+
+ /// Returns true if the given constructor or destructor is one of the
+ /// kinds that the ABI says returns 'this' (only applies when called
+ /// non-virtually for destructors).
+ ///
+ /// There currently is no way to indicate if a destructor returns 'this'
+ /// when called virtually, and code generation does not support the case.
+ virtual bool HasThisReturn(GlobalDecl GD) const { return false; }
+
+ /// If the C++ ABI requires the given type be returned in a particular way,
+ /// this method sets RetAI and returns true.
+ virtual bool classifyReturnType(CGFunctionInfo &FI) const = 0;
+
+ /// Specify how one should pass an argument of a record type.
+ enum RecordArgABI {
+ /// Pass it using the normal C aggregate rules for the ABI, potentially
+ /// introducing extra copies and passing some or all of it in registers.
+ RAA_Default = 0,
+
+ /// Pass it on the stack using its defined layout. The argument must be
+ /// evaluated directly into the correct stack position in the arguments area,
+ /// and the call machinery must not move it or introduce extra copies.
+ RAA_DirectInMemory,
+
+ /// Pass it as a pointer to temporary memory.
+ RAA_Indirect
+ };
+
+ /// Returns true if C++ allows us to copy the memory of an object of type RD
+ /// when it is passed as an argument.
+ bool canCopyArgument(const CXXRecordDecl *RD) const;
+
+ /// Returns how an argument of the given record type should be passed.
+ virtual RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const = 0;
+
+ /// Returns true if the implicit 'sret' parameter comes after the implicit
+ /// 'this' parameter of C++ instance methods.
+ virtual bool isSRetParameterAfterThis() const { return false; }
+
+ /// 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, const Expr *E, 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, const Expr *E,
+ 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);
+
+ /// Return whether or not a member pointers type is convertible to an IR type.
+ virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const {
+ return true;
+ }
+
+ /// 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);
+
+ /// \brief Computes the non-virtual adjustment needed for a member pointer
+ /// conversion along an inheritance path stored in an APValue. Unlike
+ /// getMemberPointerAdjustment(), the adjustment can be negative if the path
+ /// is from a derived type to a base type.
+ CharUnits getMemberPointerPathAdjustment(const APValue &MP);
+
+public:
+ /// Adjust the given non-null pointer to an object of polymorphic
+ /// type to point to the complete object.
+ ///
+ /// The IR type of the result should be a pointer but is otherwise
+ /// irrelevant.
+ virtual llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF,
+ llvm::Value *ptr,
+ QualType type) = 0;
+
+ virtual llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) = 0;
+
+ virtual bool shouldTypeidBeNullChecked(bool IsDeref,
+ QualType SrcRecordTy) = 0;
+ virtual void EmitBadTypeidCall(CodeGenFunction &CGF) = 0;
+ virtual llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
+ llvm::Value *ThisPtr,
+ llvm::Type *StdTypeInfoPtrTy) = 0;
+
+ virtual bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
+ QualType SrcRecordTy) = 0;
+
+ virtual llvm::Value *
+ EmitDynamicCastCall(CodeGenFunction &CGF, llvm::Value *Value,
+ QualType SrcRecordTy, QualType DestTy,
+ QualType DestRecordTy, llvm::BasicBlock *CastEnd) = 0;
+
+ virtual llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF,
+ llvm::Value *Value,
+ QualType SrcRecordTy,
+ QualType DestTy) = 0;
+
+ virtual bool EmitBadCastCall(CodeGenFunction &CGF) = 0;
+
+ virtual llvm::Value *GetVirtualBaseClassOffset(CodeGenFunction &CGF,
+ llvm::Value *This,
+ const CXXRecordDecl *ClassDecl,
+ const CXXRecordDecl *BaseClassDecl) = 0;
+
+ /// Build the signature of the given constructor variant by adding
+ /// any required parameters. For convenience, ArgTys has been initialized
+ /// with the type of 'this' and ResTy has been initialized with the type of
+ /// 'this' if HasThisReturn(GlobalDecl(Ctor, T)) is true or 'void' otherwise
+ /// (although both may be changed by the ABI).
+ ///
+ /// 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;
+
+ virtual llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
+ const CXXRecordDecl *RD);
+
+ /// Emit the code to initialize hidden members required
+ /// to handle virtual inheritance, if needed by the ABI.
+ virtual void
+ initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
+ const CXXRecordDecl *RD) {}
+
+ /// Emit constructor variants required by this ABI.
+ virtual void EmitCXXConstructors(const CXXConstructorDecl *D) = 0;
+
+ /// Build the signature of the given destructor variant by adding
+ /// any required parameters. For convenience, ArgTys has been initialized
+ /// with the type of 'this' and ResTy has been initialized with the type of
+ /// 'this' if HasThisReturn(GlobalDecl(Dtor, T)) is true or 'void' otherwise
+ /// (although both may be changed by the ABI).
+ virtual void BuildDestructorSignature(const CXXDestructorDecl *Dtor,
+ CXXDtorType T,
+ CanQualType &ResTy,
+ SmallVectorImpl<CanQualType> &ArgTys) = 0;
+
+ /// Returns true if the given destructor type should be emitted as a linkonce
+ /// delegating thunk, regardless of whether the dtor is defined in this TU or
+ /// not.
+ virtual bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
+ CXXDtorType DT) const = 0;
+
+ /// Emit destructor variants required by this ABI.
+ virtual void EmitCXXDestructors(const CXXDestructorDecl *D) = 0;
+
+ /// Get the type of the implicit "this" parameter used by a method. May return
+ /// zero if no specific type is applicable, e.g. if the ABI expects the "this"
+ /// parameter to point to some artificial offset in a complete object due to
+ /// vbases being reordered.
+ virtual const CXXRecordDecl *
+ getThisArgumentTypeForMethod(const CXXMethodDecl *MD) {
+ return MD->getParent();
+ }
+
+ /// Perform ABI-specific "this" argument adjustment required prior to
+ /// a call of a virtual function.
+ /// The "VirtualCall" argument is true iff the call itself is virtual.
+ virtual llvm::Value *
+ adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
+ llvm::Value *This,
+ bool VirtualCall) {
+ return This;
+ }
+
+ /// Build a parameter variable suitable for 'this'.
+ void buildThisParam(CodeGenFunction &CGF, FunctionArgList &Params);
+
+ /// Insert any ABI-specific implicit parameters into the parameter list for a
+ /// function. This generally involves extra data for constructors and
+ /// destructors.
+ ///
+ /// ABIs may also choose to override the return type, which has been
+ /// initialized with the type of 'this' if HasThisReturn(CGF.CurGD) is true or
+ /// the formal return type of the function otherwise.
+ virtual void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
+ FunctionArgList &Params) = 0;
+
+ /// Perform ABI-specific "this" parameter adjustment in a virtual function
+ /// prologue.
+ virtual llvm::Value *adjustThisParameterInVirtualFunctionPrologue(
+ CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) {
+ return This;
+ }
+
+ /// Emit the ABI-specific prolog for the function.
+ virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0;
+
+ /// Add any ABI-specific implicit arguments needed to call a constructor.
+ ///
+ /// \return The number of args added to the call, which is typically zero or
+ /// one.
+ virtual unsigned
+ addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
+ CXXCtorType Type, bool ForVirtualBase,
+ bool Delegating, CallArgList &Args) = 0;
+
+ /// Emit the destructor call.
+ virtual void EmitDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *DD, CXXDtorType Type,
+ bool ForVirtualBase, bool Delegating,
+ llvm::Value *This) = 0;
+
+ /// Emits the VTable definitions required for the given record type.
+ virtual void emitVTableDefinitions(CodeGenVTables &CGVT,
+ const CXXRecordDecl *RD) = 0;
+
+ /// Get the address point of the vtable for the given base subobject while
+ /// building a constructor or a destructor. On return, NeedsVirtualOffset
+ /// tells if a virtual base adjustment is needed in order to get the offset
+ /// of the base subobject.
+ virtual llvm::Value *getVTableAddressPointInStructor(
+ CodeGenFunction &CGF, const CXXRecordDecl *RD, BaseSubobject Base,
+ const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) = 0;
+
+ /// Get the address point of the vtable for the given base subobject while
+ /// building a constexpr.
+ virtual llvm::Constant *
+ getVTableAddressPointForConstExpr(BaseSubobject Base,
+ const CXXRecordDecl *VTableClass) = 0;
+
+ /// Get the address of the vtable for the given record decl which should be
+ /// used for the vptr at the given offset in RD.
+ virtual llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
+ CharUnits VPtrOffset) = 0;
+
+ /// Build a virtual function pointer in the ABI-specific way.
+ virtual llvm::Value *getVirtualFunctionPointer(CodeGenFunction &CGF,
+ GlobalDecl GD,
+ llvm::Value *This,
+ llvm::Type *Ty) = 0;
+
+ /// Emit the ABI-specific virtual destructor call.
+ virtual void EmitVirtualDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *Dtor,
+ CXXDtorType DtorType,
+ SourceLocation CallLoc,
+ llvm::Value *This) = 0;
+
+ virtual void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF,
+ GlobalDecl GD,
+ CallArgList &CallArgs) {}
+
+ /// Emit any tables needed to implement virtual inheritance. For Itanium,
+ /// this emits virtual table tables. For the MSVC++ ABI, this emits virtual
+ /// base tables.
+ virtual void emitVirtualInheritanceTables(const CXXRecordDecl *RD) = 0;
+
+ virtual void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
+ GlobalDecl GD, bool ReturnAdjustment) = 0;
+
+ virtual llvm::Value *performThisAdjustment(CodeGenFunction &CGF,
+ llvm::Value *This,
+ const ThisAdjustment &TA) = 0;
+
+ virtual llvm::Value *performReturnAdjustment(CodeGenFunction &CGF,
+ llvm::Value *Ret,
+ const ReturnAdjustment &RA) = 0;
+
+ virtual void EmitReturnFromThunk(CodeGenFunction &CGF,
+ RValue RV, QualType ResultType);
+
+ /// Gets the pure virtual member call function.
+ virtual StringRef GetPureVirtualCallName() = 0;
+
+ /// Gets the deleted virtual member call name.
+ virtual StringRef GetDeletedVirtualCallName() = 0;
+
+ /**************************** Array cookies ******************************/
+
+ /// Returns the extra size required in order to store the array
+ /// cookie for the given new-expression. 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 expr - the new-expression being allocated.
+ 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;
+ /// always a size_t
+ /// \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);
+
+ /// Return whether the given global decl needs a VTT parameter.
+ virtual bool NeedsVTTParameter(GlobalDecl GD);
+
+protected:
+ /// Returns the extra size required in order to store the array
+ /// cookie for the given type. Assumes that an array cookie is
+ /// required.
+ virtual CharUnits getArrayCookieSizeImpl(QualType elementType);
+
+ /// Reads the array cookie for an allocation which is known to have one.
+ /// This is called by the standard implementation of ReadArrayCookie.
+ ///
+ /// \param ptr - a pointer to the allocation made for an array, as a char*
+ /// \param cookieSize - the computed cookie size of an array
+ ///
+ /// Other parameters are as above.
+ ///
+ /// \return a size_t
+ virtual llvm::Value *readArrayCookieImpl(CodeGenFunction &IGF,
+ llvm::Value *ptr,
+ CharUnits cookieSize);
+
+public:
+
+ /*************************** 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) = 0;
+
+ /// Emit code to force the execution of a destructor during global
+ /// teardown. The default implementation of this uses atexit.
+ ///
+ /// \param dtor - a function taking a single pointer argument
+ /// \param addr - a pointer to pass to the destructor function.
+ virtual void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
+ llvm::Constant *dtor, llvm::Constant *addr);
+
+ /*************************** thread_local initialization ********************/
+
+ /// Emits ABI-required functions necessary to initialize thread_local
+ /// variables in this translation unit.
+ ///
+ /// \param Decls The thread_local declarations in this translation unit.
+ /// \param InitFunc If this translation unit contains any non-constant
+ /// initialization or non-trivial destruction for thread_local
+ /// variables, a function to perform the initialization. Otherwise, 0.
+ virtual void EmitThreadLocalInitFuncs(
+ ArrayRef<std::pair<const VarDecl *, llvm::GlobalVariable *> > Decls,
+ llvm::Function *InitFunc);
+
+ /// Emit a reference to a non-local thread_local variable (including
+ /// triggering the initialization of all thread_local variables in its
+ /// translation unit).
+ virtual LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
+ const VarDecl *VD,
+ QualType LValType);
};
-/// Creates an instance of a C++ ABI class.
-CGCXXABI *CreateARMCXXABI(CodeGenModule &CGM);
+// Create an instance of a C++ ABI class:
+
+/// Creates an Itanium-family ABI.
CGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM);
+
+/// Creates a Microsoft-family ABI.
CGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM);
+
}
}
projects / clang / blobdiff