1 //===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the code that handles AST -> LLVM type lowering.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
15 #define LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
18 #include "clang/Basic/ABI.h"
19 #include "clang/CodeGen/CGFunctionInfo.h"
20 #include "clang/Sema/Sema.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/IR/Module.h"
34 template <typename> class CanQual;
35 class CXXConstructorDecl;
36 class CXXDestructorDecl;
40 class FunctionProtoType;
41 class ObjCInterfaceDecl;
49 typedef CanQual<Type> CanQualType;
59 enum class StructorType {
60 Complete, // constructor or destructor
61 Base, // constructor or destructor
62 Deleting // destructor only
65 inline CXXCtorType toCXXCtorType(StructorType T) {
67 case StructorType::Complete:
69 case StructorType::Base:
71 case StructorType::Deleting:
72 llvm_unreachable("cannot have a deleting ctor");
74 llvm_unreachable("not a StructorType");
77 inline StructorType getFromCtorType(CXXCtorType T) {
80 return StructorType::Complete;
82 return StructorType::Base;
84 llvm_unreachable("not expecting a COMDAT");
85 case Ctor_CopyingClosure:
86 case Ctor_DefaultClosure:
87 llvm_unreachable("not expecting a closure");
89 llvm_unreachable("not a CXXCtorType");
92 inline CXXDtorType toCXXDtorType(StructorType T) {
94 case StructorType::Complete:
96 case StructorType::Base:
98 case StructorType::Deleting:
101 llvm_unreachable("not a StructorType");
104 inline StructorType getFromDtorType(CXXDtorType T) {
107 return StructorType::Deleting;
109 return StructorType::Complete;
111 return StructorType::Base;
113 llvm_unreachable("not expecting a COMDAT");
115 llvm_unreachable("not a CXXDtorType");
118 /// This class organizes the cross-module state that is used while lowering
119 /// AST types to LLVM types.
122 // Some of this stuff should probably be left on the CGM.
124 llvm::Module &TheModule;
125 const TargetInfo &Target;
128 // This should not be moved earlier, since its initialization depends on some
129 // of the previous reference members being already initialized
130 const ABIInfo &TheABIInfo;
132 /// The opaque type map for Objective-C interfaces. All direct
133 /// manipulation is done by the runtime interfaces, which are
134 /// responsible for coercing to the appropriate type; these opaque
135 /// types are never refined.
136 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes;
138 /// Maps clang struct type with corresponding record layout info.
139 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts;
141 /// Contains the LLVM IR type for any converted RecordDecl.
142 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes;
144 /// Hold memoized CGFunctionInfo results.
145 llvm::FoldingSet<CGFunctionInfo> FunctionInfos;
147 /// This set keeps track of records that we're currently converting
148 /// to an IR type. For example, when converting:
149 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B'
150 /// types will be in this set.
151 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut;
153 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed;
155 /// True if we didn't layout a function due to a being inside
156 /// a recursive struct conversion, set this to true.
159 SmallVector<const RecordDecl *, 8> DeferredRecords;
161 /// This map keeps cache of llvm::Types and maps clang::Type to
162 /// corresponding llvm::Type.
163 llvm::DenseMap<const Type *, llvm::Type *> TypeCache;
165 llvm::SmallSet<const Type *, 8> RecordsWithOpaqueMemberPointers;
167 unsigned ClangCallConvToLLVMCallConv(CallingConv CC);
170 CodeGenTypes(CodeGenModule &cgm);
173 const llvm::DataLayout &getDataLayout() const {
174 return TheModule.getDataLayout();
176 ASTContext &getContext() const { return Context; }
177 const ABIInfo &getABIInfo() const { return TheABIInfo; }
178 const TargetInfo &getTarget() const { return Target; }
179 CGCXXABI &getCXXABI() const { return TheCXXABI; }
180 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); }
181 const CodeGenOptions &getCodeGenOpts() const;
183 /// ConvertType - Convert type T into a llvm::Type.
184 llvm::Type *ConvertType(QualType T);
186 /// \brief Converts the GlobalDecl into an llvm::Type. This should be used
187 /// when we know the target of the function we want to convert. This is
188 /// because some functions (explicitly, those with pass_object_size
189 /// parameters) may not have the same signature as their type portrays, and
190 /// can only be called directly.
191 llvm::Type *ConvertFunctionType(QualType FT,
192 const FunctionDecl *FD = nullptr);
194 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from
195 /// ConvertType in that it is used to convert to the memory representation for
196 /// a type. For example, the scalar representation for _Bool is i1, but the
197 /// memory representation is usually i8 or i32, depending on the target.
198 llvm::Type *ConvertTypeForMem(QualType T);
200 /// GetFunctionType - Get the LLVM function type for \arg Info.
201 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info);
203 llvm::FunctionType *GetFunctionType(GlobalDecl GD);
205 /// isFuncTypeConvertible - Utility to check whether a function type can
206 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag
208 bool isFuncTypeConvertible(const FunctionType *FT);
209 bool isFuncParamTypeConvertible(QualType Ty);
211 /// Determine if a C++ inheriting constructor should have parameters matching
212 /// those of its inherited constructor.
213 bool inheritingCtorHasParams(const InheritedConstructor &Inherited,
216 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable,
217 /// given a CXXMethodDecl. If the method to has an incomplete return type,
218 /// and/or incomplete argument types, this will return the opaque type.
219 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD);
221 const CGRecordLayout &getCGRecordLayout(const RecordDecl*);
223 /// UpdateCompletedType - When we find the full definition for a TagDecl,
224 /// replace the 'opaque' type we previously made for it if applicable.
225 void UpdateCompletedType(const TagDecl *TD);
227 /// \brief Remove stale types from the type cache when an inheritance model
228 /// gets assigned to a class.
229 void RefreshTypeCacheForClass(const CXXRecordDecl *RD);
231 // The arrangement methods are split into three families:
232 // - those meant to drive the signature and prologue/epilogue
233 // of a function declaration or definition,
234 // - those meant for the computation of the LLVM type for an abstract
235 // appearance of a function, and
236 // - those meant for performing the IR-generation of a call.
237 // They differ mainly in how they deal with optional (i.e. variadic)
238 // arguments, as well as unprototyped functions.
241 // - The CGFunctionInfo for emitting a specific call site must include
242 // entries for the optional arguments.
243 // - The function type used at the call site must reflect the formal
244 // signature of the declaration being called, or else the call will
246 // - For the most part, unprototyped functions are called by casting to
247 // a formal signature inferred from the specific argument types used
248 // at the call-site. However, some targets (e.g. x86-64) screw with
249 // this for compatibility reasons.
251 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD);
253 /// Given a function info for a declaration, return the function info
254 /// for a call with the given arguments.
256 /// Often this will be able to simply return the declaration info.
257 const CGFunctionInfo &arrangeCall(const CGFunctionInfo &declFI,
258 const CallArgList &args);
260 /// Free functions are functions that are compatible with an ordinary
261 /// C function pointer type.
262 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD);
263 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args,
264 const FunctionType *Ty,
266 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty,
267 const FunctionDecl *FD);
268 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty);
270 /// A nullary function is a freestanding function of type 'void ()'.
271 /// This method works for both calls and declarations.
272 const CGFunctionInfo &arrangeNullaryFunction();
274 /// A builtin function is a freestanding function using the default
276 const CGFunctionInfo &
277 arrangeBuiltinFunctionDeclaration(QualType resultType,
278 const FunctionArgList &args);
279 const CGFunctionInfo &
280 arrangeBuiltinFunctionDeclaration(CanQualType resultType,
281 ArrayRef<CanQualType> argTypes);
282 const CGFunctionInfo &arrangeBuiltinFunctionCall(QualType resultType,
283 const CallArgList &args);
285 /// Objective-C methods are C functions with some implicit parameters.
286 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD);
287 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD,
288 QualType receiverType);
289 const CGFunctionInfo &arrangeUnprototypedObjCMessageSend(
291 const CallArgList &args);
293 /// Block invocation functions are C functions with an implicit parameter.
294 const CGFunctionInfo &arrangeBlockFunctionDeclaration(
295 const FunctionProtoType *type,
296 const FunctionArgList &args);
297 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args,
298 const FunctionType *type);
300 /// C++ methods have some special rules and also have implicit parameters.
301 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD);
302 const CGFunctionInfo &arrangeCXXStructorDeclaration(const CXXMethodDecl *MD,
304 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args,
305 const CXXConstructorDecl *D,
306 CXXCtorType CtorKind,
307 unsigned ExtraPrefixArgs,
308 unsigned ExtraSuffixArgs,
309 bool PassProtoArgs = true);
311 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args,
312 const FunctionProtoType *type,
313 RequiredArgs required,
314 unsigned numPrefixArgs);
315 const CGFunctionInfo &arrangeMSMemberPointerThunk(const CXXMethodDecl *MD);
316 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD,
318 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD,
319 const FunctionProtoType *FTP,
320 const CXXMethodDecl *MD);
322 /// "Arrange" the LLVM information for a call or type with the given
323 /// signature. This is largely an internal method; other clients
324 /// should use one of the above routines, which ultimately defer to
327 /// \param argTypes - must all actually be canonical as params
328 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType,
331 ArrayRef<CanQualType> argTypes,
332 FunctionType::ExtInfo info,
333 ArrayRef<FunctionProtoType::ExtParameterInfo> paramInfos,
336 /// \brief Compute a new LLVM record layout object for the given record.
337 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D,
338 llvm::StructType *Ty);
340 /// addRecordTypeName - Compute a name from the given record decl with an
341 /// optional suffix and name the given LLVM type using it.
342 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty,
346 public: // These are internal details of CGT that shouldn't be used externally.
347 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
348 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD);
350 /// getExpandedTypes - Expand the type \arg Ty into the LLVM
351 /// argument types it would be passed as. See ABIArgInfo::Expand.
352 void getExpandedTypes(QualType Ty,
353 SmallVectorImpl<llvm::Type *>::iterator &TI);
355 /// IsZeroInitializable - Return whether a type can be
356 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
357 bool isZeroInitializable(QualType T);
359 /// Check if the pointer type can be zero-initialized (in the C++ sense)
360 /// with an LLVM zeroinitializer.
361 bool isPointerZeroInitializable(QualType T);
363 /// IsZeroInitializable - Return whether a record type can be
364 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
365 bool isZeroInitializable(const RecordDecl *RD);
367 bool isRecordLayoutComplete(const Type *Ty) const;
368 bool noRecordsBeingLaidOut() const {
369 return RecordsBeingLaidOut.empty();
371 bool isRecordBeingLaidOut(const Type *Ty) const {
372 return RecordsBeingLaidOut.count(Ty);
377 } // end namespace CodeGen
378 } // end namespace clang