1 //===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This is the code that handles AST -> LLVM type lowering.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
15 #define LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
16
17 #include "CGCall.h"
18 #include "clang/AST/GlobalDecl.h"
19 #include "clang/CodeGen/CGFunctionInfo.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/IR/Module.h"
22 #include <vector>
23
24 namespace llvm {
25 class FunctionType;
26 class Module;
27 class DataLayout;
28 class Type;
29 class LLVMContext;
30 class StructType;
31 }
32
33 namespace clang {
34 class ABIInfo;
35 class ASTContext;
36 template <typename> class CanQual;
37 class CXXConstructorDecl;
38 class CXXDestructorDecl;
39 class CXXMethodDecl;
40 class CodeGenOptions;
41 class FieldDecl;
42 class FunctionProtoType;
43 class ObjCInterfaceDecl;
44 class ObjCIvarDecl;
45 class PointerType;
46 class QualType;
47 class RecordDecl;
48 class TagDecl;
49 class TargetInfo;
50 class Type;
51 typedef CanQual<Type> CanQualType;
52
53 namespace CodeGen {
54 class CGCXXABI;
55 class CGRecordLayout;
56 class CodeGenModule;
57 class RequiredArgs;
58
59 enum class StructorType {
60 Complete, // constructor or destructor
61 Base, // constructor or destructor
62 Deleting // destructor only
63 };
64
toCXXCtorType(StructorType T)65 inline CXXCtorType toCXXCtorType(StructorType T) {
66 switch (T) {
67 case StructorType::Complete:
68 return Ctor_Complete;
69 case StructorType::Base:
70 return Ctor_Base;
71 case StructorType::Deleting:
72 llvm_unreachable("cannot have a deleting ctor");
73 }
74 llvm_unreachable("not a StructorType");
75 }
76
getFromCtorType(CXXCtorType T)77 inline StructorType getFromCtorType(CXXCtorType T) {
78 switch (T) {
79 case Ctor_Complete:
80 return StructorType::Complete;
81 case Ctor_Base:
82 return StructorType::Base;
83 case Ctor_Comdat:
84 llvm_unreachable("not expecting a COMDAT");
85 case Ctor_CopyingClosure:
86 case Ctor_DefaultClosure:
87 llvm_unreachable("not expecting a closure");
88 }
89 llvm_unreachable("not a CXXCtorType");
90 }
91
toCXXDtorType(StructorType T)92 inline CXXDtorType toCXXDtorType(StructorType T) {
93 switch (T) {
94 case StructorType::Complete:
95 return Dtor_Complete;
96 case StructorType::Base:
97 return Dtor_Base;
98 case StructorType::Deleting:
99 return Dtor_Deleting;
100 }
101 llvm_unreachable("not a StructorType");
102 }
103
getFromDtorType(CXXDtorType T)104 inline StructorType getFromDtorType(CXXDtorType T) {
105 switch (T) {
106 case Dtor_Deleting:
107 return StructorType::Deleting;
108 case Dtor_Complete:
109 return StructorType::Complete;
110 case Dtor_Base:
111 return StructorType::Base;
112 case Dtor_Comdat:
113 llvm_unreachable("not expecting a COMDAT");
114 }
115 llvm_unreachable("not a CXXDtorType");
116 }
117
118 /// CodeGenTypes - This class organizes the cross-module state that is used
119 /// while lowering AST types to LLVM types.
120 class CodeGenTypes {
121 CodeGenModule &CGM;
122 // Some of this stuff should probably be left on the CGM.
123 ASTContext &Context;
124 llvm::Module &TheModule;
125 const llvm::DataLayout &TheDataLayout;
126 const TargetInfo &Target;
127 CGCXXABI &TheCXXABI;
128
129 // This should not be moved earlier, since its initialization depends on some
130 // of the previous reference members being already initialized
131 const ABIInfo &TheABIInfo;
132
133 /// The opaque type map for Objective-C interfaces. All direct
134 /// manipulation is done by the runtime interfaces, which are
135 /// responsible for coercing to the appropriate type; these opaque
136 /// types are never refined.
137 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes;
138
139 /// CGRecordLayouts - This maps llvm struct type with corresponding
140 /// record layout info.
141 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts;
142
143 /// RecordDeclTypes - This contains the LLVM IR type for any converted
144 /// RecordDecl.
145 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes;
146
147 /// FunctionInfos - Hold memoized CGFunctionInfo results.
148 llvm::FoldingSet<CGFunctionInfo> FunctionInfos;
149
150 /// RecordsBeingLaidOut - This set keeps track of records that we're currently
151 /// converting to an IR type. For example, when converting:
152 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B'
153 /// types will be in this set.
154 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut;
155
156 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed;
157
158 /// SkippedLayout - True if we didn't layout a function due to a being inside
159 /// a recursive struct conversion, set this to true.
160 bool SkippedLayout;
161
162 SmallVector<const RecordDecl *, 8> DeferredRecords;
163
164 private:
165 /// TypeCache - This map keeps cache of llvm::Types
166 /// and maps clang::Type to corresponding llvm::Type.
167 llvm::DenseMap<const Type *, llvm::Type *> TypeCache;
168
169 public:
170 CodeGenTypes(CodeGenModule &cgm);
171 ~CodeGenTypes();
172
getDataLayout()173 const llvm::DataLayout &getDataLayout() const { return TheDataLayout; }
getContext()174 ASTContext &getContext() const { return Context; }
getABIInfo()175 const ABIInfo &getABIInfo() const { return TheABIInfo; }
getTarget()176 const TargetInfo &getTarget() const { return Target; }
getCXXABI()177 CGCXXABI &getCXXABI() const { return TheCXXABI; }
getLLVMContext()178 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); }
179
180 /// ConvertType - Convert type T into a llvm::Type.
181 llvm::Type *ConvertType(QualType T);
182
183 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from
184 /// ConvertType in that it is used to convert to the memory representation for
185 /// a type. For example, the scalar representation for _Bool is i1, but the
186 /// memory representation is usually i8 or i32, depending on the target.
187 llvm::Type *ConvertTypeForMem(QualType T);
188
189 /// GetFunctionType - Get the LLVM function type for \arg Info.
190 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info);
191
192 llvm::FunctionType *GetFunctionType(GlobalDecl GD);
193
194 /// isFuncTypeConvertible - Utility to check whether a function type can
195 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag
196 /// type).
197 bool isFuncTypeConvertible(const FunctionType *FT);
198 bool isFuncParamTypeConvertible(QualType Ty);
199
200 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable,
201 /// given a CXXMethodDecl. If the method to has an incomplete return type,
202 /// and/or incomplete argument types, this will return the opaque type.
203 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD);
204
205 const CGRecordLayout &getCGRecordLayout(const RecordDecl*);
206
207 /// UpdateCompletedType - When we find the full definition for a TagDecl,
208 /// replace the 'opaque' type we previously made for it if applicable.
209 void UpdateCompletedType(const TagDecl *TD);
210
211 /// getNullaryFunctionInfo - Get the function info for a void()
212 /// function with standard CC.
213 const CGFunctionInfo &arrangeNullaryFunction();
214
215 // The arrangement methods are split into three families:
216 // - those meant to drive the signature and prologue/epilogue
217 // of a function declaration or definition,
218 // - those meant for the computation of the LLVM type for an abstract
219 // appearance of a function, and
220 // - those meant for performing the IR-generation of a call.
221 // They differ mainly in how they deal with optional (i.e. variadic)
222 // arguments, as well as unprototyped functions.
223 //
224 // Key points:
225 // - The CGFunctionInfo for emitting a specific call site must include
226 // entries for the optional arguments.
227 // - The function type used at the call site must reflect the formal
228 // signature of the declaration being called, or else the call will
229 // go awry.
230 // - For the most part, unprototyped functions are called by casting to
231 // a formal signature inferred from the specific argument types used
232 // at the call-site. However, some targets (e.g. x86-64) screw with
233 // this for compatibility reasons.
234
235 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD);
236 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD);
237 const CGFunctionInfo &
238 arrangeFreeFunctionDeclaration(QualType ResTy, const FunctionArgList &Args,
239 const FunctionType::ExtInfo &Info,
240 bool isVariadic);
241
242 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD);
243 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD,
244 QualType receiverType);
245
246 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD);
247 const CGFunctionInfo &arrangeCXXStructorDeclaration(const CXXMethodDecl *MD,
248 StructorType Type);
249 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args,
250 const CXXConstructorDecl *D,
251 CXXCtorType CtorKind,
252 unsigned ExtraArgs);
253 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args,
254 const FunctionType *Ty,
255 bool ChainCall);
256 const CGFunctionInfo &arrangeFreeFunctionCall(QualType ResTy,
257 const CallArgList &args,
258 FunctionType::ExtInfo info,
259 RequiredArgs required);
260 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args,
261 const FunctionType *type);
262
263 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args,
264 const FunctionProtoType *type,
265 RequiredArgs required);
266 const CGFunctionInfo &arrangeMSMemberPointerThunk(const CXXMethodDecl *MD);
267 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD,
268 CXXCtorType CT);
269
270 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty);
271 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty);
272 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD,
273 const FunctionProtoType *FTP);
274
275 /// "Arrange" the LLVM information for a call or type with the given
276 /// signature. This is largely an internal method; other clients
277 /// should use one of the above routines, which ultimately defer to
278 /// this.
279 ///
280 /// \param argTypes - must all actually be canonical as params
281 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType,
282 bool instanceMethod,
283 bool chainCall,
284 ArrayRef<CanQualType> argTypes,
285 FunctionType::ExtInfo info,
286 RequiredArgs args);
287
288 /// \brief Compute a new LLVM record layout object for the given record.
289 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D,
290 llvm::StructType *Ty);
291
292 /// addRecordTypeName - Compute a name from the given record decl with an
293 /// optional suffix and name the given LLVM type using it.
294 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty,
295 StringRef suffix);
296
297
298 public: // These are internal details of CGT that shouldn't be used externally.
299 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
300 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD);
301
302 /// getExpandedTypes - Expand the type \arg Ty into the LLVM
303 /// argument types it would be passed as. See ABIArgInfo::Expand.
304 void getExpandedTypes(QualType Ty,
305 SmallVectorImpl<llvm::Type *>::iterator &TI);
306
307 /// IsZeroInitializable - Return whether a type can be
308 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
309 bool isZeroInitializable(QualType T);
310
311 /// IsZeroInitializable - Return whether a record type can be
312 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
313 bool isZeroInitializable(const CXXRecordDecl *RD);
314
315 bool isRecordLayoutComplete(const Type *Ty) const;
noRecordsBeingLaidOut()316 bool noRecordsBeingLaidOut() const {
317 return RecordsBeingLaidOut.empty();
318 }
isRecordBeingLaidOut(const Type * Ty)319 bool isRecordBeingLaidOut(const Type *Ty) const {
320 return RecordsBeingLaidOut.count(Ty);
321 }
322
323 };
324
325 } // end namespace CodeGen
326 } // end namespace clang
327
328 #endif
329