1 //===-- llvm/Type.h - Classes for handling data types -----------*- 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 file contains the declaration of the Type class.  For more "Type"
11 // stuff, look in DerivedTypes.h.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_IR_TYPE_H
16 #define LLVM_IR_TYPE_H
17 
18 #include "llvm/ADT/APFloat.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/Support/CBindingWrapping.h"
21 #include "llvm/Support/Casting.h"
22 #include "llvm/Support/DataTypes.h"
23 #include "llvm/Support/ErrorHandling.h"
24 
25 namespace llvm {
26 
27 class PointerType;
28 class IntegerType;
29 class raw_ostream;
30 class Module;
31 class LLVMContext;
32 class LLVMContextImpl;
33 class StringRef;
34 template<class GraphType> struct GraphTraits;
35 
36 /// The instances of the Type class are immutable: once they are created,
37 /// they are never changed.  Also note that only one instance of a particular
38 /// type is ever created.  Thus seeing if two types are equal is a matter of
39 /// doing a trivial pointer comparison. To enforce that no two equal instances
40 /// are created, Type instances can only be created via static factory methods
41 /// in class Type and in derived classes.  Once allocated, Types are never
42 /// free'd.
43 ///
44 class Type {
45 public:
46   //===--------------------------------------------------------------------===//
47   /// Definitions of all of the base types for the Type system.  Based on this
48   /// value, you can cast to a class defined in DerivedTypes.h.
49   /// Note: If you add an element to this, you need to add an element to the
50   /// Type::getPrimitiveType function, or else things will break!
51   /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
52   ///
53   enum TypeID {
54     // PrimitiveTypes - make sure LastPrimitiveTyID stays up to date.
55     VoidTyID = 0,    ///<  0: type with no size
56     HalfTyID,        ///<  1: 16-bit floating point type
57     FloatTyID,       ///<  2: 32-bit floating point type
58     DoubleTyID,      ///<  3: 64-bit floating point type
59     X86_FP80TyID,    ///<  4: 80-bit floating point type (X87)
60     FP128TyID,       ///<  5: 128-bit floating point type (112-bit mantissa)
61     PPC_FP128TyID,   ///<  6: 128-bit floating point type (two 64-bits, PowerPC)
62     LabelTyID,       ///<  7: Labels
63     MetadataTyID,    ///<  8: Metadata
64     X86_MMXTyID,     ///<  9: MMX vectors (64 bits, X86 specific)
65     TokenTyID,       ///< 10: Tokens
66 
67     // Derived types... see DerivedTypes.h file.
68     // Make sure FirstDerivedTyID stays up to date!
69     IntegerTyID,     ///< 11: Arbitrary bit width integers
70     FunctionTyID,    ///< 12: Functions
71     StructTyID,      ///< 13: Structures
72     ArrayTyID,       ///< 14: Arrays
73     PointerTyID,     ///< 15: Pointers
74     VectorTyID       ///< 16: SIMD 'packed' format, or other vector type
75   };
76 
77 private:
78   /// Context - This refers to the LLVMContext in which this type was uniqued.
79   LLVMContext &Context;
80 
81   TypeID   ID : 8;            // The current base type of this type.
82   unsigned SubclassData : 24; // Space for subclasses to store data.
83 
84 protected:
85   friend class LLVMContextImpl;
Type(LLVMContext & C,TypeID tid)86   explicit Type(LLVMContext &C, TypeID tid)
87     : Context(C), ID(tid), SubclassData(0),
88       NumContainedTys(0), ContainedTys(nullptr) {}
89   ~Type() = default;
90 
getSubclassData()91   unsigned getSubclassData() const { return SubclassData; }
92 
setSubclassData(unsigned val)93   void setSubclassData(unsigned val) {
94     SubclassData = val;
95     // Ensure we don't have any accidental truncation.
96     assert(getSubclassData() == val && "Subclass data too large for field");
97   }
98 
99   /// NumContainedTys - Keeps track of how many Type*'s there are in the
100   /// ContainedTys list.
101   unsigned NumContainedTys;
102 
103   /// ContainedTys - A pointer to the array of Types contained by this Type.
104   /// For example, this includes the arguments of a function type, the elements
105   /// of a structure, the pointee of a pointer, the element type of an array,
106   /// etc.  This pointer may be 0 for types that don't contain other types
107   /// (Integer, Double, Float).
108   Type * const *ContainedTys;
109 
110 public:
111   void print(raw_ostream &O, bool IsForDebug = false) const;
112   void dump() const;
113 
114   /// getContext - Return the LLVMContext in which this type was uniqued.
getContext()115   LLVMContext &getContext() const { return Context; }
116 
117   //===--------------------------------------------------------------------===//
118   // Accessors for working with types.
119   //
120 
121   /// getTypeID - Return the type id for the type.  This will return one
122   /// of the TypeID enum elements defined above.
123   ///
getTypeID()124   TypeID getTypeID() const { return ID; }
125 
126   /// isVoidTy - Return true if this is 'void'.
isVoidTy()127   bool isVoidTy() const { return getTypeID() == VoidTyID; }
128 
129   /// isHalfTy - Return true if this is 'half', a 16-bit IEEE fp type.
isHalfTy()130   bool isHalfTy() const { return getTypeID() == HalfTyID; }
131 
132   /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
isFloatTy()133   bool isFloatTy() const { return getTypeID() == FloatTyID; }
134 
135   /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
isDoubleTy()136   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
137 
138   /// isX86_FP80Ty - Return true if this is x86 long double.
isX86_FP80Ty()139   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
140 
141   /// isFP128Ty - Return true if this is 'fp128'.
isFP128Ty()142   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
143 
144   /// isPPC_FP128Ty - Return true if this is powerpc long double.
isPPC_FP128Ty()145   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
146 
147   /// isFloatingPointTy - Return true if this is one of the six floating point
148   /// types
isFloatingPointTy()149   bool isFloatingPointTy() const {
150     return getTypeID() == HalfTyID || getTypeID() == FloatTyID ||
151            getTypeID() == DoubleTyID ||
152            getTypeID() == X86_FP80TyID || getTypeID() == FP128TyID ||
153            getTypeID() == PPC_FP128TyID;
154   }
155 
getFltSemantics()156   const fltSemantics &getFltSemantics() const {
157     switch (getTypeID()) {
158     case HalfTyID: return APFloat::IEEEhalf;
159     case FloatTyID: return APFloat::IEEEsingle;
160     case DoubleTyID: return APFloat::IEEEdouble;
161     case X86_FP80TyID: return APFloat::x87DoubleExtended;
162     case FP128TyID: return APFloat::IEEEquad;
163     case PPC_FP128TyID: return APFloat::PPCDoubleDouble;
164     default: llvm_unreachable("Invalid floating type");
165     }
166   }
167 
168   /// isX86_MMXTy - Return true if this is X86 MMX.
isX86_MMXTy()169   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
170 
171   /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
172   ///
isFPOrFPVectorTy()173   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
174 
175   /// isLabelTy - Return true if this is 'label'.
isLabelTy()176   bool isLabelTy() const { return getTypeID() == LabelTyID; }
177 
178   /// isMetadataTy - Return true if this is 'metadata'.
isMetadataTy()179   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
180 
181   /// isTokenTy - Return true if this is 'token'.
isTokenTy()182   bool isTokenTy() const { return getTypeID() == TokenTyID; }
183 
184   /// isIntegerTy - True if this is an instance of IntegerType.
185   ///
isIntegerTy()186   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
187 
188   /// isIntegerTy - Return true if this is an IntegerType of the given width.
189   bool isIntegerTy(unsigned Bitwidth) const;
190 
191   /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
192   /// integer types.
193   ///
isIntOrIntVectorTy()194   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
195 
196   /// isFunctionTy - True if this is an instance of FunctionType.
197   ///
isFunctionTy()198   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
199 
200   /// isStructTy - True if this is an instance of StructType.
201   ///
isStructTy()202   bool isStructTy() const { return getTypeID() == StructTyID; }
203 
204   /// isArrayTy - True if this is an instance of ArrayType.
205   ///
isArrayTy()206   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
207 
208   /// isPointerTy - True if this is an instance of PointerType.
209   ///
isPointerTy()210   bool isPointerTy() const { return getTypeID() == PointerTyID; }
211 
212   /// isPtrOrPtrVectorTy - Return true if this is a pointer type or a vector of
213   /// pointer types.
214   ///
isPtrOrPtrVectorTy()215   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
216 
217   /// isVectorTy - True if this is an instance of VectorType.
218   ///
isVectorTy()219   bool isVectorTy() const { return getTypeID() == VectorTyID; }
220 
221   /// canLosslesslyBitCastTo - Return true if this type could be converted
222   /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
223   /// are valid for types of the same size only where no re-interpretation of
224   /// the bits is done.
225   /// @brief Determine if this type could be losslessly bitcast to Ty
226   bool canLosslesslyBitCastTo(Type *Ty) const;
227 
228   /// isEmptyTy - Return true if this type is empty, that is, it has no
229   /// elements or all its elements are empty.
230   bool isEmptyTy() const;
231 
232   /// isFirstClassType - Return true if the type is "first class", meaning it
233   /// is a valid type for a Value.
234   ///
isFirstClassType()235   bool isFirstClassType() const {
236     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
237   }
238 
239   /// isSingleValueType - Return true if the type is a valid type for a
240   /// register in codegen.  This includes all first-class types except struct
241   /// and array types.
242   ///
isSingleValueType()243   bool isSingleValueType() const {
244     return isFloatingPointTy() || isX86_MMXTy() || isIntegerTy() ||
245            isPointerTy() || isVectorTy();
246   }
247 
248   /// isAggregateType - Return true if the type is an aggregate type. This
249   /// means it is valid as the first operand of an insertvalue or
250   /// extractvalue instruction. This includes struct and array types, but
251   /// does not include vector types.
252   ///
isAggregateType()253   bool isAggregateType() const {
254     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
255   }
256 
257   /// isSized - Return true if it makes sense to take the size of this type.  To
258   /// get the actual size for a particular target, it is reasonable to use the
259   /// DataLayout subsystem to do this.
260   ///
261   bool isSized(SmallPtrSetImpl<Type*> *Visited = nullptr) const {
262     // If it's a primitive, it is always sized.
263     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
264         getTypeID() == PointerTyID ||
265         getTypeID() == X86_MMXTyID)
266       return true;
267     // If it is not something that can have a size (e.g. a function or label),
268     // it doesn't have a size.
269     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID &&
270         getTypeID() != VectorTyID)
271       return false;
272     // Otherwise we have to try harder to decide.
273     return isSizedDerivedType(Visited);
274   }
275 
276   /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
277   /// primitive type.  These are fixed by LLVM and are not target dependent.
278   /// This will return zero if the type does not have a size or is not a
279   /// primitive type.
280   ///
281   /// Note that this may not reflect the size of memory allocated for an
282   /// instance of the type or the number of bytes that are written when an
283   /// instance of the type is stored to memory. The DataLayout class provides
284   /// additional query functions to provide this information.
285   ///
286   unsigned getPrimitiveSizeInBits() const LLVM_READONLY;
287 
288   /// getScalarSizeInBits - If this is a vector type, return the
289   /// getPrimitiveSizeInBits value for the element type. Otherwise return the
290   /// getPrimitiveSizeInBits value for this type.
291   unsigned getScalarSizeInBits() const LLVM_READONLY;
292 
293   /// getFPMantissaWidth - Return the width of the mantissa of this type.  This
294   /// is only valid on floating point types.  If the FP type does not
295   /// have a stable mantissa (e.g. ppc long double), this method returns -1.
296   int getFPMantissaWidth() const;
297 
298   /// getScalarType - If this is a vector type, return the element type,
299   /// otherwise return 'this'.
300   Type *getScalarType() const LLVM_READONLY;
301 
302   //===--------------------------------------------------------------------===//
303   // Type Iteration support.
304   //
305   typedef Type * const *subtype_iterator;
subtype_begin()306   subtype_iterator subtype_begin() const { return ContainedTys; }
subtype_end()307   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
subtypes()308   ArrayRef<Type*> subtypes() const {
309     return makeArrayRef(subtype_begin(), subtype_end());
310   }
311 
312   typedef std::reverse_iterator<subtype_iterator> subtype_reverse_iterator;
subtype_rbegin()313   subtype_reverse_iterator subtype_rbegin() const {
314     return subtype_reverse_iterator(subtype_end());
315   }
subtype_rend()316   subtype_reverse_iterator subtype_rend() const {
317     return subtype_reverse_iterator(subtype_begin());
318   }
319 
320   /// getContainedType - This method is used to implement the type iterator
321   /// (defined at the end of the file).  For derived types, this returns the
322   /// types 'contained' in the derived type.
323   ///
getContainedType(unsigned i)324   Type *getContainedType(unsigned i) const {
325     assert(i < NumContainedTys && "Index out of range!");
326     return ContainedTys[i];
327   }
328 
329   /// getNumContainedTypes - Return the number of types in the derived type.
330   ///
getNumContainedTypes()331   unsigned getNumContainedTypes() const { return NumContainedTys; }
332 
333   //===--------------------------------------------------------------------===//
334   // Helper methods corresponding to subclass methods.  This forces a cast to
335   // the specified subclass and calls its accessor.  "getVectorNumElements" (for
336   // example) is shorthand for cast<VectorType>(Ty)->getNumElements().  This is
337   // only intended to cover the core methods that are frequently used, helper
338   // methods should not be added here.
339 
340   unsigned getIntegerBitWidth() const;
341 
342   Type *getFunctionParamType(unsigned i) const;
343   unsigned getFunctionNumParams() const;
344   bool isFunctionVarArg() const;
345 
346   StringRef getStructName() const;
347   unsigned getStructNumElements() const;
348   Type *getStructElementType(unsigned N) const;
349 
350   Type *getSequentialElementType() const;
351 
352   uint64_t getArrayNumElements() const;
getArrayElementType()353   Type *getArrayElementType() const { return getSequentialElementType(); }
354 
355   unsigned getVectorNumElements() const;
getVectorElementType()356   Type *getVectorElementType() const { return getSequentialElementType(); }
357 
getPointerElementType()358   Type *getPointerElementType() const { return getSequentialElementType(); }
359 
360   /// \brief Get the address space of this pointer or pointer vector type.
361   unsigned getPointerAddressSpace() const;
362 
363   //===--------------------------------------------------------------------===//
364   // Static members exported by the Type class itself.  Useful for getting
365   // instances of Type.
366   //
367 
368   /// getPrimitiveType - Return a type based on an identifier.
369   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
370 
371   //===--------------------------------------------------------------------===//
372   // These are the builtin types that are always available.
373   //
374   static Type *getVoidTy(LLVMContext &C);
375   static Type *getLabelTy(LLVMContext &C);
376   static Type *getHalfTy(LLVMContext &C);
377   static Type *getFloatTy(LLVMContext &C);
378   static Type *getDoubleTy(LLVMContext &C);
379   static Type *getMetadataTy(LLVMContext &C);
380   static Type *getX86_FP80Ty(LLVMContext &C);
381   static Type *getFP128Ty(LLVMContext &C);
382   static Type *getPPC_FP128Ty(LLVMContext &C);
383   static Type *getX86_MMXTy(LLVMContext &C);
384   static Type *getTokenTy(LLVMContext &C);
385   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
386   static IntegerType *getInt1Ty(LLVMContext &C);
387   static IntegerType *getInt8Ty(LLVMContext &C);
388   static IntegerType *getInt16Ty(LLVMContext &C);
389   static IntegerType *getInt32Ty(LLVMContext &C);
390   static IntegerType *getInt64Ty(LLVMContext &C);
391   static IntegerType *getInt128Ty(LLVMContext &C);
392 
393   //===--------------------------------------------------------------------===//
394   // Convenience methods for getting pointer types with one of the above builtin
395   // types as pointee.
396   //
397   static PointerType *getHalfPtrTy(LLVMContext &C, unsigned AS = 0);
398   static PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
399   static PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
400   static PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
401   static PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
402   static PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
403   static PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
404   static PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS = 0);
405   static PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
406   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
407   static PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
408   static PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
409   static PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
410 
411   /// getPointerTo - Return a pointer to the current type.  This is equivalent
412   /// to PointerType::get(Foo, AddrSpace).
413   PointerType *getPointerTo(unsigned AddrSpace = 0) const;
414 
415 private:
416   /// isSizedDerivedType - Derived types like structures and arrays are sized
417   /// iff all of the members of the type are sized as well.  Since asking for
418   /// their size is relatively uncommon, move this operation out of line.
419   bool isSizedDerivedType(SmallPtrSetImpl<Type*> *Visited = nullptr) const;
420 };
421 
422 // Printing of types.
423 static inline raw_ostream &operator<<(raw_ostream &OS, Type &T) {
424   T.print(OS);
425   return OS;
426 }
427 
428 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
429 template <> struct isa_impl<PointerType, Type> {
430   static inline bool doit(const Type &Ty) {
431     return Ty.getTypeID() == Type::PointerTyID;
432   }
433 };
434 
435 //===----------------------------------------------------------------------===//
436 // Provide specializations of GraphTraits to be able to treat a type as a
437 // graph of sub types.
438 
439 template <> struct GraphTraits<Type *> {
440   typedef Type NodeType;
441   typedef Type::subtype_iterator ChildIteratorType;
442 
443   static inline NodeType *getEntryNode(Type *T) { return T; }
444   static inline ChildIteratorType child_begin(NodeType *N) {
445     return N->subtype_begin();
446   }
447   static inline ChildIteratorType child_end(NodeType *N) {
448     return N->subtype_end();
449   }
450 };
451 
452 template <> struct GraphTraits<const Type*> {
453   typedef const Type NodeType;
454   typedef Type::subtype_iterator ChildIteratorType;
455 
456   static inline NodeType *getEntryNode(NodeType *T) { return T; }
457   static inline ChildIteratorType child_begin(NodeType *N) {
458     return N->subtype_begin();
459   }
460   static inline ChildIteratorType child_end(NodeType *N) {
461     return N->subtype_end();
462   }
463 };
464 
465 // Create wrappers for C Binding types (see CBindingWrapping.h).
466 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
467 
468 /* Specialized opaque type conversions.
469  */
470 inline Type **unwrap(LLVMTypeRef* Tys) {
471   return reinterpret_cast<Type**>(Tys);
472 }
473 
474 inline LLVMTypeRef *wrap(Type **Tys) {
475   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
476 }
477 
478 } // End llvm namespace
479 
480 #endif
481