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-c/Core.h"
19 #include "llvm/ADT/APFloat.h"
20 #include "llvm/ADT/SmallPtrSet.h"
21 #include "llvm/Support/CBindingWrapping.h"
22 #include "llvm/Support/Casting.h"
23 #include "llvm/Support/DataTypes.h"
24 #include "llvm/Support/ErrorHandling.h"
25 
26 namespace llvm {
27 
28 class PointerType;
29 class IntegerType;
30 class raw_ostream;
31 class Module;
32 class LLVMContext;
33 class LLVMContextImpl;
34 class StringRef;
35 template<class GraphType> struct GraphTraits;
36 
37 /// The instances of the Type class are immutable: once they are created,
38 /// they are never changed.  Also note that only one instance of a particular
39 /// type is ever created.  Thus seeing if two types are equal is a matter of
40 /// doing a trivial pointer comparison. To enforce that no two equal instances
41 /// are created, Type instances can only be created via static factory methods
42 /// in class Type and in derived classes.  Once allocated, Types are never
43 /// free'd.
44 ///
45 class Type {
46 public:
47   //===--------------------------------------------------------------------===//
48   /// Definitions of all of the base types for the Type system.  Based on this
49   /// value, you can cast to a class defined in DerivedTypes.h.
50   /// Note: If you add an element to this, you need to add an element to the
51   /// Type::getPrimitiveType function, or else things will break!
52   /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
53   ///
54   enum TypeID {
55     // PrimitiveTypes - make sure LastPrimitiveTyID stays up to date.
56     VoidTyID = 0,    ///<  0: type with no size
57     HalfTyID,        ///<  1: 16-bit floating point type
58     FloatTyID,       ///<  2: 32-bit floating point type
59     DoubleTyID,      ///<  3: 64-bit floating point type
60     X86_FP80TyID,    ///<  4: 80-bit floating point type (X87)
61     FP128TyID,       ///<  5: 128-bit floating point type (112-bit mantissa)
62     PPC_FP128TyID,   ///<  6: 128-bit floating point type (two 64-bits, PowerPC)
63     LabelTyID,       ///<  7: Labels
64     MetadataTyID,    ///<  8: Metadata
65     X86_MMXTyID,     ///<  9: MMX vectors (64 bits, X86 specific)
66 
67     // Derived types... see DerivedTypes.h file.
68     // Make sure FirstDerivedTyID stays up to date!
69     IntegerTyID,     ///< 10: Arbitrary bit width integers
70     FunctionTyID,    ///< 11: Functions
71     StructTyID,      ///< 12: Structures
72     ArrayTyID,       ///< 13: Arrays
73     PointerTyID,     ///< 14: Pointers
74     VectorTyID       ///< 15: 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   // Due to Ubuntu GCC bug 910363:
82   // https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/910363
83   // Bitpack ID and SubclassData manually.
84   // Note: TypeID : low 8 bit; SubclassData : high 24 bit.
85   uint32_t IDAndSubclassData;
86 
87 protected:
88   friend class LLVMContextImpl;
Type(LLVMContext & C,TypeID tid)89   explicit Type(LLVMContext &C, TypeID tid)
90     : Context(C), IDAndSubclassData(0),
91       NumContainedTys(0), ContainedTys(nullptr) {
92     setTypeID(tid);
93   }
94   ~Type() = default;
95 
setTypeID(TypeID ID)96   void setTypeID(TypeID ID) {
97     IDAndSubclassData = (ID & 0xFF) | (IDAndSubclassData & 0xFFFFFF00);
98     assert(getTypeID() == ID && "TypeID data too large for field");
99   }
100 
getSubclassData()101   unsigned getSubclassData() const { return IDAndSubclassData >> 8; }
102 
setSubclassData(unsigned val)103   void setSubclassData(unsigned val) {
104     IDAndSubclassData = (IDAndSubclassData & 0xFF) | (val << 8);
105     // Ensure we don't have any accidental truncation.
106     assert(getSubclassData() == val && "Subclass data too large for field");
107   }
108 
109   /// NumContainedTys - Keeps track of how many Type*'s there are in the
110   /// ContainedTys list.
111   unsigned NumContainedTys;
112 
113   /// ContainedTys - A pointer to the array of Types contained by this Type.
114   /// For example, this includes the arguments of a function type, the elements
115   /// of a structure, the pointee of a pointer, the element type of an array,
116   /// etc.  This pointer may be 0 for types that don't contain other types
117   /// (Integer, Double, Float).
118   Type * const *ContainedTys;
119 
120 public:
121   void print(raw_ostream &O) const;
122   void dump() const;
123 
124   /// getContext - Return the LLVMContext in which this type was uniqued.
getContext()125   LLVMContext &getContext() const { return Context; }
126 
127   //===--------------------------------------------------------------------===//
128   // Accessors for working with types.
129   //
130 
131   /// getTypeID - Return the type id for the type.  This will return one
132   /// of the TypeID enum elements defined above.
133   ///
getTypeID()134   TypeID getTypeID() const { return (TypeID)(IDAndSubclassData & 0xFF); }
135 
136   /// isVoidTy - Return true if this is 'void'.
isVoidTy()137   bool isVoidTy() const { return getTypeID() == VoidTyID; }
138 
139   /// isHalfTy - Return true if this is 'half', a 16-bit IEEE fp type.
isHalfTy()140   bool isHalfTy() const { return getTypeID() == HalfTyID; }
141 
142   /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
isFloatTy()143   bool isFloatTy() const { return getTypeID() == FloatTyID; }
144 
145   /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
isDoubleTy()146   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
147 
148   /// isX86_FP80Ty - Return true if this is x86 long double.
isX86_FP80Ty()149   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
150 
151   /// isFP128Ty - Return true if this is 'fp128'.
isFP128Ty()152   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
153 
154   /// isPPC_FP128Ty - Return true if this is powerpc long double.
isPPC_FP128Ty()155   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
156 
157   /// isFloatingPointTy - Return true if this is one of the six floating point
158   /// types
isFloatingPointTy()159   bool isFloatingPointTy() const {
160     return getTypeID() == HalfTyID || getTypeID() == FloatTyID ||
161            getTypeID() == DoubleTyID ||
162            getTypeID() == X86_FP80TyID || getTypeID() == FP128TyID ||
163            getTypeID() == PPC_FP128TyID;
164   }
165 
getFltSemantics()166   const fltSemantics &getFltSemantics() const {
167     switch (getTypeID()) {
168     case HalfTyID: return APFloat::IEEEhalf;
169     case FloatTyID: return APFloat::IEEEsingle;
170     case DoubleTyID: return APFloat::IEEEdouble;
171     case X86_FP80TyID: return APFloat::x87DoubleExtended;
172     case FP128TyID: return APFloat::IEEEquad;
173     case PPC_FP128TyID: return APFloat::PPCDoubleDouble;
174     default: llvm_unreachable("Invalid floating type");
175     }
176   }
177 
178   /// isX86_MMXTy - Return true if this is X86 MMX.
isX86_MMXTy()179   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
180 
181   /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
182   ///
isFPOrFPVectorTy()183   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
184 
185   /// isLabelTy - Return true if this is 'label'.
isLabelTy()186   bool isLabelTy() const { return getTypeID() == LabelTyID; }
187 
188   /// isMetadataTy - Return true if this is 'metadata'.
isMetadataTy()189   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
190 
191   /// isIntegerTy - True if this is an instance of IntegerType.
192   ///
isIntegerTy()193   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
194 
195   /// isIntegerTy - Return true if this is an IntegerType of the given width.
196   bool isIntegerTy(unsigned Bitwidth) const;
197 
198   /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
199   /// integer types.
200   ///
isIntOrIntVectorTy()201   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
202 
203   /// isFunctionTy - True if this is an instance of FunctionType.
204   ///
isFunctionTy()205   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
206 
207   /// isStructTy - True if this is an instance of StructType.
208   ///
isStructTy()209   bool isStructTy() const { return getTypeID() == StructTyID; }
210 
211   /// isArrayTy - True if this is an instance of ArrayType.
212   ///
isArrayTy()213   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
214 
215   /// isPointerTy - True if this is an instance of PointerType.
216   ///
isPointerTy()217   bool isPointerTy() const { return getTypeID() == PointerTyID; }
218 
219   /// isPtrOrPtrVectorTy - Return true if this is a pointer type or a vector of
220   /// pointer types.
221   ///
isPtrOrPtrVectorTy()222   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
223 
224   /// isVectorTy - True if this is an instance of VectorType.
225   ///
isVectorTy()226   bool isVectorTy() const { return getTypeID() == VectorTyID; }
227 
228   /// canLosslesslyBitCastTo - Return true if this type could be converted
229   /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
230   /// are valid for types of the same size only where no re-interpretation of
231   /// the bits is done.
232   /// @brief Determine if this type could be losslessly bitcast to Ty
233   bool canLosslesslyBitCastTo(Type *Ty) const;
234 
235   /// isEmptyTy - Return true if this type is empty, that is, it has no
236   /// elements or all its elements are empty.
237   bool isEmptyTy() const;
238 
239   /// isFirstClassType - Return true if the type is "first class", meaning it
240   /// is a valid type for a Value.
241   ///
isFirstClassType()242   bool isFirstClassType() const {
243     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
244   }
245 
246   /// isSingleValueType - Return true if the type is a valid type for a
247   /// register in codegen.  This includes all first-class types except struct
248   /// and array types.
249   ///
isSingleValueType()250   bool isSingleValueType() const {
251     return isFloatingPointTy() || isX86_MMXTy() || isIntegerTy() ||
252            isPointerTy() || isVectorTy();
253   }
254 
255   /// isAggregateType - Return true if the type is an aggregate type. This
256   /// means it is valid as the first operand of an insertvalue or
257   /// extractvalue instruction. This includes struct and array types, but
258   /// does not include vector types.
259   ///
isAggregateType()260   bool isAggregateType() const {
261     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
262   }
263 
264   /// isSized - Return true if it makes sense to take the size of this type.  To
265   /// get the actual size for a particular target, it is reasonable to use the
266   /// DataLayout subsystem to do this.
267   ///
268   bool isSized(SmallPtrSetImpl<const Type*> *Visited = nullptr) const {
269     // If it's a primitive, it is always sized.
270     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
271         getTypeID() == PointerTyID ||
272         getTypeID() == X86_MMXTyID)
273       return true;
274     // If it is not something that can have a size (e.g. a function or label),
275     // it doesn't have a size.
276     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID &&
277         getTypeID() != VectorTyID)
278       return false;
279     // Otherwise we have to try harder to decide.
280     return isSizedDerivedType(Visited);
281   }
282 
283   /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
284   /// primitive type.  These are fixed by LLVM and are not target dependent.
285   /// This will return zero if the type does not have a size or is not a
286   /// primitive type.
287   ///
288   /// Note that this may not reflect the size of memory allocated for an
289   /// instance of the type or the number of bytes that are written when an
290   /// instance of the type is stored to memory. The DataLayout class provides
291   /// additional query functions to provide this information.
292   ///
293   unsigned getPrimitiveSizeInBits() const LLVM_READONLY;
294 
295   /// getScalarSizeInBits - If this is a vector type, return the
296   /// getPrimitiveSizeInBits value for the element type. Otherwise return the
297   /// getPrimitiveSizeInBits value for this type.
298   unsigned getScalarSizeInBits() const LLVM_READONLY;
299 
300   /// getFPMantissaWidth - Return the width of the mantissa of this type.  This
301   /// is only valid on floating point types.  If the FP type does not
302   /// have a stable mantissa (e.g. ppc long double), this method returns -1.
303   int getFPMantissaWidth() const;
304 
305   /// getScalarType - If this is a vector type, return the element type,
306   /// otherwise return 'this'.
307   const Type *getScalarType() const LLVM_READONLY;
308   Type *getScalarType() LLVM_READONLY;
309 
310   //===--------------------------------------------------------------------===//
311   // Type Iteration support.
312   //
313   typedef Type * const *subtype_iterator;
subtype_begin()314   subtype_iterator subtype_begin() const { return ContainedTys; }
subtype_end()315   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
subtypes()316   ArrayRef<Type*> subtypes() const {
317     return makeArrayRef(subtype_begin(), subtype_end());
318   }
319 
320   typedef std::reverse_iterator<subtype_iterator> subtype_reverse_iterator;
subtype_rbegin()321   subtype_reverse_iterator subtype_rbegin() const {
322     return subtype_reverse_iterator(subtype_end());
323   }
subtype_rend()324   subtype_reverse_iterator subtype_rend() const {
325     return subtype_reverse_iterator(subtype_begin());
326   }
327 
328   /// getContainedType - This method is used to implement the type iterator
329   /// (defined at the end of the file).  For derived types, this returns the
330   /// types 'contained' in the derived type.
331   ///
getContainedType(unsigned i)332   Type *getContainedType(unsigned i) const {
333     assert(i < NumContainedTys && "Index out of range!");
334     return ContainedTys[i];
335   }
336 
337   /// getNumContainedTypes - Return the number of types in the derived type.
338   ///
getNumContainedTypes()339   unsigned getNumContainedTypes() const { return NumContainedTys; }
340 
341   //===--------------------------------------------------------------------===//
342   // Helper methods corresponding to subclass methods.  This forces a cast to
343   // the specified subclass and calls its accessor.  "getVectorNumElements" (for
344   // example) is shorthand for cast<VectorType>(Ty)->getNumElements().  This is
345   // only intended to cover the core methods that are frequently used, helper
346   // methods should not be added here.
347 
348   unsigned getIntegerBitWidth() const;
349 
350   Type *getFunctionParamType(unsigned i) const;
351   unsigned getFunctionNumParams() const;
352   bool isFunctionVarArg() const;
353 
354   StringRef getStructName() const;
355   unsigned getStructNumElements() const;
356   Type *getStructElementType(unsigned N) const;
357 
358   Type *getSequentialElementType() const;
359 
360   uint64_t getArrayNumElements() const;
getArrayElementType()361   Type *getArrayElementType() const { return getSequentialElementType(); }
362 
363   unsigned getVectorNumElements() const;
getVectorElementType()364   Type *getVectorElementType() const { return getSequentialElementType(); }
365 
getPointerElementType()366   Type *getPointerElementType() const { return getSequentialElementType(); }
367 
368   /// \brief Get the address space of this pointer or pointer vector type.
369   unsigned getPointerAddressSpace() const;
370 
371   //===--------------------------------------------------------------------===//
372   // Static members exported by the Type class itself.  Useful for getting
373   // instances of Type.
374   //
375 
376   /// getPrimitiveType - Return a type based on an identifier.
377   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
378 
379   //===--------------------------------------------------------------------===//
380   // These are the builtin types that are always available.
381   //
382   static Type *getVoidTy(LLVMContext &C);
383   static Type *getLabelTy(LLVMContext &C);
384   static Type *getHalfTy(LLVMContext &C);
385   static Type *getFloatTy(LLVMContext &C);
386   static Type *getDoubleTy(LLVMContext &C);
387   static Type *getMetadataTy(LLVMContext &C);
388   static Type *getX86_FP80Ty(LLVMContext &C);
389   static Type *getFP128Ty(LLVMContext &C);
390   static Type *getPPC_FP128Ty(LLVMContext &C);
391   static Type *getX86_MMXTy(LLVMContext &C);
392   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
393   static IntegerType *getInt1Ty(LLVMContext &C);
394   static IntegerType *getInt8Ty(LLVMContext &C);
395   static IntegerType *getInt16Ty(LLVMContext &C);
396   static IntegerType *getInt32Ty(LLVMContext &C);
397   static IntegerType *getInt64Ty(LLVMContext &C);
398 
399   //===--------------------------------------------------------------------===//
400   // Convenience methods for getting pointer types with one of the above builtin
401   // types as pointee.
402   //
403   static PointerType *getHalfPtrTy(LLVMContext &C, unsigned AS = 0);
404   static PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
405   static PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
406   static PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
407   static PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
408   static PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
409   static PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
410   static PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS = 0);
411   static PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
412   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
413   static PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
414   static PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
415   static PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
416 
417   /// getPointerTo - Return a pointer to the current type.  This is equivalent
418   /// to PointerType::get(Foo, AddrSpace).
419   PointerType *getPointerTo(unsigned AddrSpace = 0);
420 
421 private:
422   /// isSizedDerivedType - Derived types like structures and arrays are sized
423   /// iff all of the members of the type are sized as well.  Since asking for
424   /// their size is relatively uncommon, move this operation out of line.
425   bool isSizedDerivedType(SmallPtrSetImpl<const Type*> *Visited = nullptr) const;
426 };
427 
428 // Printing of types.
429 static inline raw_ostream &operator<<(raw_ostream &OS, Type &T) {
430   T.print(OS);
431   return OS;
432 }
433 
434 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
435 template <> struct isa_impl<PointerType, Type> {
436   static inline bool doit(const Type &Ty) {
437     return Ty.getTypeID() == Type::PointerTyID;
438   }
439 };
440 
441 
442 //===----------------------------------------------------------------------===//
443 // Provide specializations of GraphTraits to be able to treat a type as a
444 // graph of sub types.
445 
446 
447 template <> struct GraphTraits<Type*> {
448   typedef Type NodeType;
449   typedef Type::subtype_iterator ChildIteratorType;
450 
451   static inline NodeType *getEntryNode(Type *T) { return T; }
452   static inline ChildIteratorType child_begin(NodeType *N) {
453     return N->subtype_begin();
454   }
455   static inline ChildIteratorType child_end(NodeType *N) {
456     return N->subtype_end();
457   }
458 };
459 
460 template <> struct GraphTraits<const Type*> {
461   typedef const Type NodeType;
462   typedef Type::subtype_iterator ChildIteratorType;
463 
464   static inline NodeType *getEntryNode(NodeType *T) { return T; }
465   static inline ChildIteratorType child_begin(NodeType *N) {
466     return N->subtype_begin();
467   }
468   static inline ChildIteratorType child_end(NodeType *N) {
469     return N->subtype_end();
470   }
471 };
472 
473 // Create wrappers for C Binding types (see CBindingWrapping.h).
474 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
475 
476 /* Specialized opaque type conversions.
477  */
478 inline Type **unwrap(LLVMTypeRef* Tys) {
479   return reinterpret_cast<Type**>(Tys);
480 }
481 
482 inline LLVMTypeRef *wrap(Type **Tys) {
483   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
484 }
485 
486 } // End llvm namespace
487 
488 #endif
489