clang  5.0.0
CodeGenTypes.h
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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/Basic/ABI.h"
20 #include "clang/Sema/Sema.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/IR/Module.h"
23 
24 namespace llvm {
25 class FunctionType;
26 class DataLayout;
27 class Type;
28 class LLVMContext;
29 class StructType;
30 }
31 
32 namespace clang {
33 class ASTContext;
34 template <typename> class CanQual;
35 class CXXConstructorDecl;
36 class CXXDestructorDecl;
37 class CXXMethodDecl;
38 class CodeGenOptions;
39 class FieldDecl;
40 class FunctionProtoType;
41 class ObjCInterfaceDecl;
42 class ObjCIvarDecl;
43 class PointerType;
44 class QualType;
45 class RecordDecl;
46 class TagDecl;
47 class TargetInfo;
48 class Type;
49 typedef CanQual<Type> CanQualType;
50 class GlobalDecl;
51 
52 namespace CodeGen {
53 class ABIInfo;
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 
66  switch (T) {
68  return Ctor_Complete;
69  case StructorType::Base:
70  return Ctor_Base;
72  llvm_unreachable("cannot have a deleting ctor");
73  }
74  llvm_unreachable("not a StructorType");
75 }
76 
78  switch (T) {
79  case Ctor_Complete:
81  case Ctor_Base:
82  return StructorType::Base;
83  case Ctor_Comdat:
84  llvm_unreachable("not expecting a COMDAT");
87  llvm_unreachable("not expecting a closure");
88  }
89  llvm_unreachable("not a CXXCtorType");
90 }
91 
93  switch (T) {
95  return Dtor_Complete;
96  case StructorType::Base:
97  return Dtor_Base;
99  return Dtor_Deleting;
100  }
101  llvm_unreachable("not a StructorType");
102 }
103 
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 /// This class organizes the cross-module state that is used while lowering
119 /// AST types to LLVM types.
121  CodeGenModule &CGM;
122  // Some of this stuff should probably be left on the CGM.
123  ASTContext &Context;
124  llvm::Module &TheModule;
125  const TargetInfo &Target;
126  CGCXXABI &TheCXXABI;
127 
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;
131 
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;
137 
138  /// Maps clang struct type with corresponding record layout info.
139  llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts;
140 
141  /// Contains the LLVM IR type for any converted RecordDecl.
142  llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes;
143 
144  /// Hold memoized CGFunctionInfo results.
145  llvm::FoldingSet<CGFunctionInfo> FunctionInfos;
146 
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;
152 
153  llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed;
154 
155  /// True if we didn't layout a function due to a being inside
156  /// a recursive struct conversion, set this to true.
157  bool SkippedLayout;
158 
159  SmallVector<const RecordDecl *, 8> DeferredRecords;
160 
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;
164 
165  llvm::SmallSet<const Type *, 8> RecordsWithOpaqueMemberPointers;
166 
167  unsigned ClangCallConvToLLVMCallConv(CallingConv CC);
168 
169 public:
171  ~CodeGenTypes();
172 
173  const llvm::DataLayout &getDataLayout() const {
174  return TheModule.getDataLayout();
175  }
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;
182 
183  /// ConvertType - Convert type T into a llvm::Type.
185 
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.
192  const FunctionDecl *FD = nullptr);
193 
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.
199 
200  /// GetFunctionType - Get the LLVM function type for \arg Info.
201  llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info);
202 
203  llvm::FunctionType *GetFunctionType(GlobalDecl GD);
204 
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
207  /// type).
208  bool isFuncTypeConvertible(const FunctionType *FT);
210 
211  /// Determine if a C++ inheriting constructor should have parameters matching
212  /// those of its inherited constructor.
213  bool inheritingCtorHasParams(const InheritedConstructor &Inherited,
214  CXXCtorType Type);
215 
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.
220 
222 
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);
226 
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);
230 
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.
239  //
240  // Key points:
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
245  // go awry.
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.
250 
252 
253  /// Given a function info for a declaration, return the function info
254  /// for a call with the given arguments.
255  ///
256  /// Often this will be able to simply return the declaration info.
257  const CGFunctionInfo &arrangeCall(const CGFunctionInfo &declFI,
258  const CallArgList &args);
259 
260  /// Free functions are functions that are compatible with an ordinary
261  /// C function pointer type.
264  const FunctionType *Ty,
265  bool ChainCall);
267  const FunctionDecl *FD);
269 
270  /// A nullary function is a freestanding function of type 'void ()'.
271  /// This method works for both calls and declarations.
273 
274  /// A builtin function is a freestanding function using the default
275  /// C conventions.
276  const CGFunctionInfo &
278  const FunctionArgList &args);
279  const CGFunctionInfo &
281  ArrayRef<CanQualType> argTypes);
283  const CallArgList &args);
284 
285  /// Objective-C methods are C functions with some implicit parameters.
288  QualType receiverType);
290  QualType returnType,
291  const CallArgList &args);
292 
293  /// Block invocation functions are C functions with an implicit parameter.
295  const FunctionProtoType *type,
296  const FunctionArgList &args);
298  const FunctionType *type);
299 
300  /// C++ methods have some special rules and also have implicit parameters.
305  const CXXConstructorDecl *D,
306  CXXCtorType CtorKind,
307  unsigned ExtraPrefixArgs,
308  unsigned ExtraSuffixArgs,
309  bool PassProtoArgs = true);
310 
312  const FunctionProtoType *type,
313  RequiredArgs required,
314  unsigned numPrefixArgs);
317  CXXCtorType CT);
319  const FunctionProtoType *FTP,
320  const CXXMethodDecl *MD);
321 
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
325  /// this.
326  ///
327  /// \param argTypes - must all actually be canonical as params
329  bool instanceMethod,
330  bool chainCall,
331  ArrayRef<CanQualType> argTypes,
334  RequiredArgs args);
335 
336  /// \brief Compute a new LLVM record layout object for the given record.
338  llvm::StructType *Ty);
339 
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,
343  StringRef suffix);
344 
345 
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);
349 
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,
354 
355  /// IsZeroInitializable - Return whether a type can be
356  /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
358 
359  /// Check if the pointer type can be zero-initialized (in the C++ sense)
360  /// with an LLVM zeroinitializer.
362 
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);
366 
367  bool isRecordLayoutComplete(const Type *Ty) const;
368  bool noRecordsBeingLaidOut() const {
369  return RecordsBeingLaidOut.empty();
370  }
371  bool isRecordBeingLaidOut(const Type *Ty) const {
372  return RecordsBeingLaidOut.count(Ty);
373  }
374 
375 };
376 
377 } // end namespace CodeGen
378 } // end namespace clang
379 
380 #endif
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:636
void getExpandedTypes(QualType Ty, SmallVectorImpl< llvm::Type * >::iterator &TI)
getExpandedTypes - Expand the type
Definition: CGCall.cpp:962
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1618
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:610
Complete object ctor.
Definition: ABI.h:26
A (possibly-)qualified type.
Definition: Type.h:616
void UpdateCompletedType(const TagDecl *TD)
UpdateCompletedType - When we find the full definition for a TagDecl, replace the 'opaque' type we pr...
CGRecordLayout - This class handles struct and union layout info while lowering AST types to LLVM typ...
The COMDAT used for ctors.
Definition: ABI.h:28
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:2923
const CGFunctionInfo & arrangeFreeFunctionType(CanQual< FunctionProtoType > Ty, const FunctionDecl *FD)
Arrange the argument and result information for a value of the given freestanding function type...
Definition: CGCall.cpp:187
void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, StringRef suffix)
addRecordTypeName - Compute a name from the given record decl with an optional suffix and name the gi...
const CGFunctionInfo & arrangeCXXMethodType(const CXXRecordDecl *RD, const FunctionProtoType *FTP, const CXXMethodDecl *MD)
Arrange the argument and result information for a call to an unknown C++ non-static member function o...
Definition: CGCall.cpp:242
CGCXXABI & getCXXABI() const
Definition: CodeGenTypes.h:179
ASTContext & getContext() const
Definition: CodeGenTypes.h:176
The base class of the type hierarchy.
Definition: Type.h:1303
bool isFuncTypeConvertible(const FunctionType *FT)
isFuncTypeConvertible - Utility to check whether a function type can be converted to an LLVM type (i...
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2329
Default closure variant of a ctor.
Definition: ABI.h:30
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:113
const CGFunctionInfo & arrangeCXXStructorDeclaration(const CXXMethodDecl *MD, StructorType Type)
Definition: CGCall.cpp:288
llvm::Type * ConvertTypeForMem(QualType T)
ConvertTypeForMem - Convert type T into a llvm::Type.
RecordDecl - Represents a struct/union/class.
Definition: Decl.h:3354
Description of a constructor that was inherited from a base class.
Definition: DeclCXX.h:2303
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
StructorType getFromDtorType(CXXDtorType T)
Definition: CodeGenTypes.h:104
Base object ctor.
Definition: ABI.h:27
Deleting dtor.
Definition: ABI.h:35
const CGFunctionInfo & arrangeCXXConstructorCall(const CallArgList &Args, const CXXConstructorDecl *D, CXXCtorType CtorKind, unsigned ExtraPrefixArgs, unsigned ExtraSuffixArgs, bool PassProtoArgs=true)
Arrange a call to a C++ method, passing the given arguments.
Definition: CGCall.cpp:378
const CGFunctionInfo & arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, QualType receiverType)
Arrange the argument and result information for the function type through which to perform a send to ...
Definition: CGCall.cpp:455
const CGFunctionInfo & arrangeCall(const CGFunctionInfo &declFI, const CallArgList &args)
Given a function info for a declaration, return the function info for a call with the given arguments...
Definition: CGCall.cpp:685
Enums/classes describing ABI related information about constructors, destructors and thunks...
const CGFunctionInfo & arrangeCXXMethodDeclaration(const CXXMethodDecl *MD)
C++ methods have some special rules and also have implicit parameters.
Definition: CGCall.cpp:263
const CGFunctionInfo & arrangeLLVMFunctionInfo(CanQualType returnType, bool instanceMethod, bool chainCall, ArrayRef< CanQualType > argTypes, FunctionType::ExtInfo info, ArrayRef< FunctionProtoType::ExtParameterInfo > paramInfos, RequiredArgs args)
"Arrange" the LLVM information for a call or type with the given signature.
Definition: CGCall.cpp:720
const CGFunctionInfo & arrangeGlobalDeclaration(GlobalDecl GD)
Definition: CGCall.cpp:493
const CGFunctionInfo & arrangeUnprototypedObjCMessageSend(QualType returnType, const CallArgList &args)
Definition: CGCall.cpp:482
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3129
bool isPointerZeroInitializable(QualType T)
Check if the pointer type can be zero-initialized (in the C++ sense) with an LLVM zeroinitializer...
Exposes information about the current target.
Definition: TargetInfo.h:54
CXXDtorType
C++ destructor types.
Definition: ABI.h:34
CodeGenTypes(CodeGenModule &cgm)
const CGFunctionInfo & arrangeNullaryFunction()
A nullary function is a freestanding function of type 'void ()'.
Definition: CGCall.cpp:678
A class for recording the number of arguments that a function signature requires. ...
const CGFunctionInfo & arrangeBuiltinFunctionCall(QualType resultType, const CallArgList &args)
Definition: CGCall.cpp:623
Base object dtor.
Definition: ABI.h:37
The COMDAT used for dtors.
Definition: ABI.h:38
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:232
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:29
The l-value was considered opaque, so the alignment was determined from a type.
const llvm::DataLayout & getDataLayout() const
Definition: CodeGenTypes.h:173
bool inheritingCtorHasParams(const InheritedConstructor &Inherited, CXXCtorType Type)
Determine if a C++ inheriting constructor should have parameters matching those of its inherited cons...
Definition: CGCall.cpp:278
TagDecl - Represents the declaration of a struct/union/class/enum.
Definition: Decl.h:2816
const CGFunctionInfo & arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD)
Objective-C methods are C functions with some implicit parameters.
Definition: CGCall.cpp:442
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1903
CanQual< Type > CanQualType
Represents a canonical, potentially-qualified type.
llvm::LLVMContext & getLLVMContext()
Definition: CodeGenTypes.h:180
Complete object dtor.
Definition: ABI.h:36
CXXCtorType
C++ constructor types.
Definition: ABI.h:25
const CGFunctionInfo & arrangeBlockFunctionCall(const CallArgList &args, const FunctionType *type)
A block function is essentially a free function with an extra implicit argument.
Definition: CGCall.cpp:603
bool isRecordBeingLaidOut(const Type *Ty) const
Definition: CodeGenTypes.h:371
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:276
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
const CodeGenOptions & getCodeGenOpts() const
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:2126
CXXDtorType toCXXDtorType(StructorType T)
Definition: CodeGenTypes.h:92
const CGFunctionInfo & arrangeFunctionDeclaration(const FunctionDecl *FD)
Free functions are functions that are compatible with an ordinary C function pointer type...
Definition: CGCall.cpp:419
llvm::StructType * ConvertRecordDeclType(const RecordDecl *TD)
ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
StructorType getFromCtorType(CXXCtorType T)
Definition: CodeGenTypes.h:77
llvm::Type * ConvertFunctionType(QualType FT, const FunctionDecl *FD=nullptr)
Converts the GlobalDecl into an llvm::Type.
Implements C++ ABI-specific code generation functions.
Definition: CGCXXABI.h:44
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:120
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
const CGFunctionInfo & arrangeMSMemberPointerThunk(const CXXMethodDecl *MD)
Arrange a thunk that takes 'this' as the first parameter followed by varargs.
Definition: CGCall.cpp:512
bool isRecordLayoutComplete(const Type *Ty) const
isRecordLayoutComplete - Return true if the specified type is already completely laid out...
llvm::Type * GetFunctionTypeForVTable(GlobalDecl GD)
GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable, given a CXXMethodDecl...
Definition: CGCall.cpp:1647
Represents a C++ struct/union/class.
Definition: DeclCXX.h:267
bool isFuncParamTypeConvertible(QualType Ty)
isFuncParamTypeConvertible - Return true if the specified type in a function parameter or result posi...
const TargetInfo & getTarget() const
Definition: CodeGenTypes.h:178
Copying closure variant of a ctor.
Definition: ABI.h:29
void RefreshTypeCacheForClass(const CXXRecordDecl *RD)
Remove stale types from the type cache when an inheritance model gets assigned to a class...
ABIInfo - Target specific hooks for defining how a type should be passed or returned from functions...
Definition: ABIInfo.h:51
const CGFunctionInfo & arrangeMSCtorClosure(const CXXConstructorDecl *CD, CXXCtorType CT)
Definition: CGCall.cpp:522
const ABIInfo & getABIInfo() const
Definition: CodeGenTypes.h:177
const CGFunctionInfo & arrangeFreeFunctionCall(const CallArgList &Args, const FunctionType *Ty, bool ChainCall)
Figure out the rules for calling a function with the given formal type using the given arguments...
Definition: CGCall.cpp:593
CXXCtorType toCXXCtorType(StructorType T)
Definition: CodeGenTypes.h:65
CGRecordLayout * ComputeRecordLayout(const RecordDecl *D, llvm::StructType *Ty)
Compute a new LLVM record layout object for the given record.
const CGRecordLayout & getCGRecordLayout(const RecordDecl *)
getCGRecordLayout - Return record layout info for the given record decl.
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:182
const CGFunctionInfo & arrangeCXXMethodCall(const CallArgList &args, const FunctionProtoType *type, RequiredArgs required, unsigned numPrefixArgs)
Arrange a call to a C++ method, passing the given arguments.
Definition: CGCall.cpp:658
bool noRecordsBeingLaidOut() const
Definition: CodeGenTypes.h:368
bool isZeroInitializable(QualType T)
IsZeroInitializable - Return whether a type can be zero-initialized (in the C++ sense) with an LLVM z...
A class which abstracts out some details necessary for making a call.
Definition: Type.h:2948
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1519