1//===--- Specifiers.h - Declaration and Type Specifiers ---------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// Defines various enumerations that describe declaration and
11/// type specifiers.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_BASIC_SPECIFIERS_H
16#define LLVM_CLANG_BASIC_SPECIFIERS_H
17
18#include "llvm/ADT/StringRef.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/Support/ErrorHandling.h"
21
22namespace clang {
23
24 /// Define the meaning of possible values of the kind in ExplicitSpecifier.
25 enum class ExplicitSpecKind : unsigned {
26 ResolvedFalse,
27 ResolvedTrue,
28 Unresolved,
29 };
30
31 /// Define the kind of constexpr specifier.
32 enum class ConstexprSpecKind { Unspecified, Constexpr, Consteval, Constinit };
33
34 /// Specifies the width of a type, e.g., short, long, or long long.
35 enum class TypeSpecifierWidth { Unspecified, Short, Long, LongLong };
36
37 /// Specifies the signedness of a type, e.g., signed or unsigned.
38 enum class TypeSpecifierSign { Unspecified, Signed, Unsigned };
39
40 enum class TypeSpecifiersPipe { Unspecified, Pipe };
41
42 /// Specifies the kind of type.
43 enum TypeSpecifierType {
44 TST_unspecified,
45 TST_void,
46 TST_char,
47 TST_wchar, // C++ wchar_t
48 TST_char8, // C++20 char8_t (proposed)
49 TST_char16, // C++11 char16_t
50 TST_char32, // C++11 char32_t
51 TST_int,
52 TST_int128,
53 TST_extint, // Extended Int types.
54 TST_half, // OpenCL half, ARM NEON __fp16
55 TST_Float16, // C11 extension ISO/IEC TS 18661-3
56 TST_Accum, // ISO/IEC JTC1 SC22 WG14 N1169 Extension
57 TST_Fract,
58 TST_BFloat16,
59 TST_float,
60 TST_double,
61 TST_float128,
62 TST_bool, // _Bool
63 TST_decimal32, // _Decimal32
64 TST_decimal64, // _Decimal64
65 TST_decimal128, // _Decimal128
66 TST_enum,
67 TST_union,
68 TST_struct,
69 TST_class, // C++ class type
70 TST_interface, // C++ (Microsoft-specific) __interface type
71 TST_typename, // Typedef, C++ class-name or enum name, etc.
72 TST_typeofType,
73 TST_typeofExpr,
74 TST_decltype, // C++11 decltype
75 TST_underlyingType, // __underlying_type for C++11
76 TST_auto, // C++11 auto
77 TST_decltype_auto, // C++1y decltype(auto)
78 TST_auto_type, // __auto_type extension
79 TST_unknown_anytype, // __unknown_anytype extension
80 TST_atomic, // C11 _Atomic
81#define GENERIC_IMAGE_TYPE(ImgType, Id) TST_##ImgType##_t, // OpenCL image types
82#include "clang/Basic/OpenCLImageTypes.def"
83 TST_error // erroneous type
84 };
85
86 /// Structure that packs information about the type specifiers that
87 /// were written in a particular type specifier sequence.
88 struct WrittenBuiltinSpecs {
89 static_assert(TST_error < 1 << 6, "Type bitfield not wide enough for TST");
90 /*DeclSpec::TST*/ unsigned Type : 6;
91 /*DeclSpec::TSS*/ unsigned Sign : 2;
92 /*TypeSpecifierWidth*/ unsigned Width : 2;
93 unsigned ModeAttr : 1;
94 };
95
96 /// A C++ access specifier (public, private, protected), plus the
97 /// special value "none" which means different things in different contexts.
98 enum AccessSpecifier {
99 AS_public,
100 AS_protected,
101 AS_private,
102 AS_none
103 };
104
105 /// The categorization of expression values, currently following the
106 /// C++11 scheme.
107 enum ExprValueKind {
108 /// An r-value expression (a pr-value in the C++11 taxonomy)
109 /// produces a temporary value.
110 VK_RValue,
111
112 /// An l-value expression is a reference to an object with
113 /// independent storage.
114 VK_LValue,
115
116 /// An x-value expression is a reference to an object with
117 /// independent storage but which can be "moved", i.e.
118 /// efficiently cannibalized for its resources.
119 VK_XValue
120 };
121
122 /// A further classification of the kind of object referenced by an
123 /// l-value or x-value.
124 enum ExprObjectKind {
125 /// An ordinary object is located at an address in memory.
126 OK_Ordinary,
127
128 /// A bitfield object is a bitfield on a C or C++ record.
129 OK_BitField,
130
131 /// A vector component is an element or range of elements on a vector.
132 OK_VectorComponent,
133
134 /// An Objective-C property is a logical field of an Objective-C
135 /// object which is read and written via Objective-C method calls.
136 OK_ObjCProperty,
137
138 /// An Objective-C array/dictionary subscripting which reads an
139 /// object or writes at the subscripted array/dictionary element via
140 /// Objective-C method calls.
141 OK_ObjCSubscript,
142
143 /// A matrix component is a single element of a matrix.
144 OK_MatrixComponent
145 };
146
147 /// The reason why a DeclRefExpr does not constitute an odr-use.
148 enum NonOdrUseReason {
149 /// This is an odr-use.
150 NOUR_None = 0,
151 /// This name appears in an unevaluated operand.
152 NOUR_Unevaluated,
153 /// This name appears as a potential result of an lvalue-to-rvalue
154 /// conversion that is a constant expression.
155 NOUR_Constant,
156 /// This name appears as a potential result of a discarded value
157 /// expression.
158 NOUR_Discarded,
159 };
160
161 /// Describes the kind of template specialization that a
162 /// particular template specialization declaration represents.
163 enum TemplateSpecializationKind {
164 /// This template specialization was formed from a template-id but
165 /// has not yet been declared, defined, or instantiated.
166 TSK_Undeclared = 0,
167 /// This template specialization was implicitly instantiated from a
168 /// template. (C++ [temp.inst]).
169 TSK_ImplicitInstantiation,
170 /// This template specialization was declared or defined by an
171 /// explicit specialization (C++ [temp.expl.spec]) or partial
172 /// specialization (C++ [temp.class.spec]).
173 TSK_ExplicitSpecialization,
174 /// This template specialization was instantiated from a template
175 /// due to an explicit instantiation declaration request
176 /// (C++11 [temp.explicit]).
177 TSK_ExplicitInstantiationDeclaration,
178 /// This template specialization was instantiated from a template
179 /// due to an explicit instantiation definition request
180 /// (C++ [temp.explicit]).
181 TSK_ExplicitInstantiationDefinition
182 };
183
184 /// Determine whether this template specialization kind refers
185 /// to an instantiation of an entity (as opposed to a non-template or
186 /// an explicit specialization).
187 inline bool isTemplateInstantiation(TemplateSpecializationKind Kind) {
188 return Kind != TSK_Undeclared && Kind != TSK_ExplicitSpecialization;
189 }
190
191 /// True if this template specialization kind is an explicit
192 /// specialization, explicit instantiation declaration, or explicit
193 /// instantiation definition.
194 inline bool isTemplateExplicitInstantiationOrSpecialization(
195 TemplateSpecializationKind Kind) {
196 switch (Kind) {
197 case TSK_ExplicitSpecialization:
198 case TSK_ExplicitInstantiationDeclaration:
199 case TSK_ExplicitInstantiationDefinition:
200 return true;
201
202 case TSK_Undeclared:
203 case TSK_ImplicitInstantiation:
204 return false;
205 }
206 llvm_unreachable("bad template specialization kind");
207 }
208
209 /// Thread storage-class-specifier.
210 enum ThreadStorageClassSpecifier {
211 TSCS_unspecified,
212 /// GNU __thread.
213 TSCS___thread,
214 /// C++11 thread_local. Implies 'static' at block scope, but not at
215 /// class scope.
216 TSCS_thread_local,
217 /// C11 _Thread_local. Must be combined with either 'static' or 'extern'
218 /// if used at block scope.
219 TSCS__Thread_local
220 };
221
222 /// Storage classes.
223 enum StorageClass {
224 // These are legal on both functions and variables.
225 SC_None,
226 SC_Extern,
227 SC_Static,
228 SC_PrivateExtern,
229
230 // These are only legal on variables.
231 SC_Auto,
232 SC_Register
233 };
234
235 /// Checks whether the given storage class is legal for functions.
236 inline bool isLegalForFunction(StorageClass SC) {
237 return SC <= SC_PrivateExtern;
238 }
239
240 /// Checks whether the given storage class is legal for variables.
241 inline bool isLegalForVariable(StorageClass SC) {
242 return true;
243 }
244
245 /// In-class initialization styles for non-static data members.
246 enum InClassInitStyle {
247 ICIS_NoInit, ///< No in-class initializer.
248 ICIS_CopyInit, ///< Copy initialization.
249 ICIS_ListInit ///< Direct list-initialization.
250 };
251
252 /// CallingConv - Specifies the calling convention that a function uses.
253 enum CallingConv {
254 CC_C, // __attribute__((cdecl))
255 CC_X86StdCall, // __attribute__((stdcall))
256 CC_X86FastCall, // __attribute__((fastcall))
257 CC_X86ThisCall, // __attribute__((thiscall))
258 CC_X86VectorCall, // __attribute__((vectorcall))
259 CC_X86Pascal, // __attribute__((pascal))
260 CC_Win64, // __attribute__((ms_abi))
261 CC_X86_64SysV, // __attribute__((sysv_abi))
262 CC_X86RegCall, // __attribute__((regcall))
263 CC_AAPCS, // __attribute__((pcs("aapcs")))
264 CC_AAPCS_VFP, // __attribute__((pcs("aapcs-vfp")))
265 CC_IntelOclBicc, // __attribute__((intel_ocl_bicc))
266 CC_SpirFunction, // default for OpenCL functions on SPIR target
267 CC_OpenCLKernel, // inferred for OpenCL kernels
268 CC_Swift, // __attribute__((swiftcall))
269 CC_PreserveMost, // __attribute__((preserve_most))
270 CC_PreserveAll, // __attribute__((preserve_all))
271 CC_AArch64VectorCall, // __attribute__((aarch64_vector_pcs))
272 };
273
274 /// Checks whether the given calling convention supports variadic
275 /// calls. Unprototyped calls also use the variadic call rules.
276 inline bool supportsVariadicCall(CallingConv CC) {
277 switch (CC) {
278 case CC_X86StdCall:
279 case CC_X86FastCall:
280 case CC_X86ThisCall:
281 case CC_X86RegCall:
282 case CC_X86Pascal:
283 case CC_X86VectorCall:
284 case CC_SpirFunction:
285 case CC_OpenCLKernel:
286 case CC_Swift:
287 return false;
288 default:
289 return true;
290 }
291 }
292
293 /// The storage duration for an object (per C++ [basic.stc]).
294 enum StorageDuration {
295 SD_FullExpression, ///< Full-expression storage duration (for temporaries).
296 SD_Automatic, ///< Automatic storage duration (most local variables).
297 SD_Thread, ///< Thread storage duration.
298 SD_Static, ///< Static storage duration.
299 SD_Dynamic ///< Dynamic storage duration.
300 };
301
302 /// Describes the nullability of a particular type.
303 enum class NullabilityKind : uint8_t {
304 /// Values of this type can never be null.
305 NonNull = 0,
306 /// Values of this type can be null.
307 Nullable,
308 /// Whether values of this type can be null is (explicitly)
309 /// unspecified. This captures a (fairly rare) case where we
310 /// can't conclude anything about the nullability of the type even
311 /// though it has been considered.
312 Unspecified,
313 // Generally behaves like Nullable, except when used in a block parameter
314 // that was imported into a swift async method. There, swift will assume
315 // that the parameter can get null even if no error occured. _Nullable
316 // parameters are assumed to only get null on error.
317 NullableResult,
318 };
319
320 /// Return true if \p L has a weaker nullability annotation than \p R. The
321 /// ordering is: Unspecified < Nullable < NonNull.
322 inline bool hasWeakerNullability(NullabilityKind L, NullabilityKind R) {
323 return uint8_t(L) > uint8_t(R);
324 }
325
326 /// Retrieve the spelling of the given nullability kind.
327 llvm::StringRef getNullabilitySpelling(NullabilityKind kind,
328 bool isContextSensitive = false);
329
330 /// Kinds of parameter ABI.
331 enum class ParameterABI {
332 /// This parameter uses ordinary ABI rules for its type.
333 Ordinary,
334
335 /// This parameter (which must have pointer type) is a Swift
336 /// indirect result parameter.
337 SwiftIndirectResult,
338
339 /// This parameter (which must have pointer-to-pointer type) uses
340 /// the special Swift error-result ABI treatment. There can be at
341 /// most one parameter on a given function that uses this treatment.
342 SwiftErrorResult,
343
344 /// This parameter (which must have pointer type) uses the special
345 /// Swift context-pointer ABI treatment. There can be at
346 /// most one parameter on a given function that uses this treatment.
347 SwiftContext
348 };
349
350 /// Assigned inheritance model for a class in the MS C++ ABI. Must match order
351 /// of spellings in MSInheritanceAttr.
352 enum class MSInheritanceModel {
353 Single = 0,
354 Multiple = 1,
355 Virtual = 2,
356 Unspecified = 3,
357 };
358
359 llvm::StringRef getParameterABISpelling(ParameterABI kind);
360
361 inline llvm::StringRef getAccessSpelling(AccessSpecifier AS) {
362 switch (AS) {
363 case AccessSpecifier::AS_public:
364 return "public";
365 case AccessSpecifier::AS_protected:
366 return "protected";
367 case AccessSpecifier::AS_private:
368 return "private";
369 case AccessSpecifier::AS_none:
370 return {};
371 }
372 llvm_unreachable("Unknown AccessSpecifier");
373 }
374} // end namespace clang
375
376#endif // LLVM_CLANG_BASIC_SPECIFIERS_H
377