1 //===--- Specifiers.h - Declaration and Type Specifiers ---------*- 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 /// \file
11 /// \brief Defines various enumerations that describe declaration and
12 /// type specifiers.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CLANG_BASIC_SPECIFIERS_H
17 #define LLVM_CLANG_BASIC_SPECIFIERS_H
18 
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/Support/DataTypes.h"
21 #include "llvm/Support/ErrorHandling.h"
22 
23 namespace clang {
24   /// \brief Specifies the width of a type, e.g., short, long, or long long.
25   enum TypeSpecifierWidth {
26     TSW_unspecified,
27     TSW_short,
28     TSW_long,
29     TSW_longlong
30   };
31 
32   /// \brief Specifies the signedness of a type, e.g., signed or unsigned.
33   enum TypeSpecifierSign {
34     TSS_unspecified,
35     TSS_signed,
36     TSS_unsigned
37   };
38 
39   /// \brief Specifies the kind of type.
40   enum TypeSpecifierType {
41     TST_unspecified,
42     TST_void,
43     TST_char,
44     TST_wchar,        // C++ wchar_t
45     TST_char16,       // C++11 char16_t
46     TST_char32,       // C++11 char32_t
47     TST_int,
48     TST_int128,
49     TST_half,         // OpenCL half, ARM NEON __fp16
50     TST_float,
51     TST_double,
52     TST_bool,         // _Bool
53     TST_decimal32,    // _Decimal32
54     TST_decimal64,    // _Decimal64
55     TST_decimal128,   // _Decimal128
56     TST_enum,
57     TST_union,
58     TST_struct,
59     TST_class,        // C++ class type
60     TST_interface,    // C++ (Microsoft-specific) __interface type
61     TST_typename,     // Typedef, C++ class-name or enum name, etc.
62     TST_typeofType,
63     TST_typeofExpr,
64     TST_decltype,         // C++11 decltype
65     TST_underlyingType,   // __underlying_type for C++11
66     TST_auto,             // C++11 auto
67     TST_decltype_auto,    // C++1y decltype(auto)
68     TST_auto_type,        // __auto_type extension
69     TST_unknown_anytype,  // __unknown_anytype extension
70     TST_atomic,           // C11 _Atomic
71     TST_error         // erroneous type
72   };
73 
74   /// \brief Structure that packs information about the type specifiers that
75   /// were written in a particular type specifier sequence.
76   struct WrittenBuiltinSpecs {
77     /*DeclSpec::TST*/ unsigned Type  : 5;
78     /*DeclSpec::TSS*/ unsigned Sign  : 2;
79     /*DeclSpec::TSW*/ unsigned Width : 2;
80     bool ModeAttr : 1;
81   };
82 
83   /// \brief A C++ access specifier (public, private, protected), plus the
84   /// special value "none" which means different things in different contexts.
85   enum AccessSpecifier {
86     AS_public,
87     AS_protected,
88     AS_private,
89     AS_none
90   };
91 
92   /// \brief The categorization of expression values, currently following the
93   /// C++11 scheme.
94   enum ExprValueKind {
95     /// \brief An r-value expression (a pr-value in the C++11 taxonomy)
96     /// produces a temporary value.
97     VK_RValue,
98 
99     /// \brief An l-value expression is a reference to an object with
100     /// independent storage.
101     VK_LValue,
102 
103     /// \brief An x-value expression is a reference to an object with
104     /// independent storage but which can be "moved", i.e.
105     /// efficiently cannibalized for its resources.
106     VK_XValue
107   };
108 
109   /// \brief A further classification of the kind of object referenced by an
110   /// l-value or x-value.
111   enum ExprObjectKind {
112     /// An ordinary object is located at an address in memory.
113     OK_Ordinary,
114 
115     /// A bitfield object is a bitfield on a C or C++ record.
116     OK_BitField,
117 
118     /// A vector component is an element or range of elements on a vector.
119     OK_VectorComponent,
120 
121     /// An Objective-C property is a logical field of an Objective-C
122     /// object which is read and written via Objective-C method calls.
123     OK_ObjCProperty,
124 
125     /// An Objective-C array/dictionary subscripting which reads an
126     /// object or writes at the subscripted array/dictionary element via
127     /// Objective-C method calls.
128     OK_ObjCSubscript
129   };
130 
131   /// \brief Describes the kind of template specialization that a
132   /// particular template specialization declaration represents.
133   enum TemplateSpecializationKind {
134     /// This template specialization was formed from a template-id but
135     /// has not yet been declared, defined, or instantiated.
136     TSK_Undeclared = 0,
137     /// This template specialization was implicitly instantiated from a
138     /// template. (C++ [temp.inst]).
139     TSK_ImplicitInstantiation,
140     /// This template specialization was declared or defined by an
141     /// explicit specialization (C++ [temp.expl.spec]) or partial
142     /// specialization (C++ [temp.class.spec]).
143     TSK_ExplicitSpecialization,
144     /// This template specialization was instantiated from a template
145     /// due to an explicit instantiation declaration request
146     /// (C++11 [temp.explicit]).
147     TSK_ExplicitInstantiationDeclaration,
148     /// This template specialization was instantiated from a template
149     /// due to an explicit instantiation definition request
150     /// (C++ [temp.explicit]).
151     TSK_ExplicitInstantiationDefinition
152   };
153 
154   /// \brief Determine whether this template specialization kind refers
155   /// to an instantiation of an entity (as opposed to a non-template or
156   /// an explicit specialization).
isTemplateInstantiation(TemplateSpecializationKind Kind)157   inline bool isTemplateInstantiation(TemplateSpecializationKind Kind) {
158     return Kind != TSK_Undeclared && Kind != TSK_ExplicitSpecialization;
159   }
160 
161   /// \brief True if this template specialization kind is an explicit
162   /// specialization, explicit instantiation declaration, or explicit
163   /// instantiation definition.
isTemplateExplicitInstantiationOrSpecialization(TemplateSpecializationKind Kind)164   inline bool isTemplateExplicitInstantiationOrSpecialization(
165       TemplateSpecializationKind Kind) {
166     switch (Kind) {
167     case TSK_ExplicitSpecialization:
168     case TSK_ExplicitInstantiationDeclaration:
169     case TSK_ExplicitInstantiationDefinition:
170       return true;
171 
172     case TSK_Undeclared:
173     case TSK_ImplicitInstantiation:
174       return false;
175     }
176     llvm_unreachable("bad template specialization kind");
177   }
178 
179   /// \brief Thread storage-class-specifier.
180   enum ThreadStorageClassSpecifier {
181     TSCS_unspecified,
182     /// GNU __thread.
183     TSCS___thread,
184     /// C++11 thread_local. Implies 'static' at block scope, but not at
185     /// class scope.
186     TSCS_thread_local,
187     /// C11 _Thread_local. Must be combined with either 'static' or 'extern'
188     /// if used at block scope.
189     TSCS__Thread_local
190   };
191 
192   /// \brief Storage classes.
193   enum StorageClass {
194     // These are legal on both functions and variables.
195     SC_None,
196     SC_Extern,
197     SC_Static,
198     SC_PrivateExtern,
199 
200     // These are only legal on variables.
201     SC_Auto,
202     SC_Register
203   };
204 
205   /// \brief Checks whether the given storage class is legal for functions.
isLegalForFunction(StorageClass SC)206   inline bool isLegalForFunction(StorageClass SC) {
207     return SC <= SC_PrivateExtern;
208   }
209 
210   /// \brief Checks whether the given storage class is legal for variables.
isLegalForVariable(StorageClass SC)211   inline bool isLegalForVariable(StorageClass SC) {
212     return true;
213   }
214 
215   /// \brief In-class initialization styles for non-static data members.
216   enum InClassInitStyle {
217     ICIS_NoInit,   ///< No in-class initializer.
218     ICIS_CopyInit, ///< Copy initialization.
219     ICIS_ListInit  ///< Direct list-initialization.
220   };
221 
222   /// \brief CallingConv - Specifies the calling convention that a function uses.
223   enum CallingConv {
224     CC_C,           // __attribute__((cdecl))
225     CC_X86StdCall,  // __attribute__((stdcall))
226     CC_X86FastCall, // __attribute__((fastcall))
227     CC_X86ThisCall, // __attribute__((thiscall))
228     CC_X86VectorCall, // __attribute__((vectorcall))
229     CC_X86Pascal,   // __attribute__((pascal))
230     CC_X86_64Win64, // __attribute__((ms_abi))
231     CC_X86_64SysV,  // __attribute__((sysv_abi))
232     CC_AAPCS,       // __attribute__((pcs("aapcs")))
233     CC_AAPCS_VFP,   // __attribute__((pcs("aapcs-vfp")))
234     CC_IntelOclBicc, // __attribute__((intel_ocl_bicc))
235     CC_SpirFunction, // default for OpenCL functions on SPIR target
236     CC_SpirKernel    // inferred for OpenCL kernels on SPIR target
237   };
238 
239   /// \brief Checks whether the given calling convention supports variadic
240   /// calls. Unprototyped calls also use the variadic call rules.
supportsVariadicCall(CallingConv CC)241   inline bool supportsVariadicCall(CallingConv CC) {
242     switch (CC) {
243     case CC_X86StdCall:
244     case CC_X86FastCall:
245     case CC_X86ThisCall:
246     case CC_X86Pascal:
247     case CC_X86VectorCall:
248     case CC_SpirFunction:
249     case CC_SpirKernel:
250       return false;
251     default:
252       return true;
253     }
254   }
255 
256   /// \brief The storage duration for an object (per C++ [basic.stc]).
257   enum StorageDuration {
258     SD_FullExpression, ///< Full-expression storage duration (for temporaries).
259     SD_Automatic,      ///< Automatic storage duration (most local variables).
260     SD_Thread,         ///< Thread storage duration.
261     SD_Static,         ///< Static storage duration.
262     SD_Dynamic         ///< Dynamic storage duration.
263   };
264 
265   /// Describes the nullability of a particular type.
266   enum class NullabilityKind : uint8_t {
267     /// Values of this type can never be null.
268     NonNull = 0,
269     /// Values of this type can be null.
270     Nullable,
271     /// Whether values of this type can be null is (explicitly)
272     /// unspecified. This captures a (fairly rare) case where we
273     /// can't conclude anything about the nullability of the type even
274     /// though it has been considered.
275     Unspecified
276   };
277 
278   /// Retrieve the spelling of the given nullability kind.
279   llvm::StringRef getNullabilitySpelling(NullabilityKind kind,
280                                          bool isContextSensitive = false);
281 } // end namespace clang
282 
283 #endif // LLVM_CLANG_BASIC_SPECIFIERS_H
284