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 llvm {
23class raw_ostream;
24} // namespace llvm
25namespace clang {
26
27 /// Define the meaning of possible values of the kind in ExplicitSpecifier.
28 enum class ExplicitSpecKind : unsigned {
29 ResolvedFalse,
30 ResolvedTrue,
31 Unresolved,
32 };
33
34 /// Define the kind of constexpr specifier.
35 enum class ConstexprSpecKind { Unspecified, Constexpr, Consteval, Constinit };
36
37 /// In an if statement, this denotes whether the statement is
38 /// a constexpr or consteval if statement.
39 enum class IfStatementKind : unsigned {
40 Ordinary,
41 Constexpr,
42 ConstevalNonNegated,
43 ConstevalNegated
44 };
45
46 /// Specifies the width of a type, e.g., short, long, or long long.
47 enum class TypeSpecifierWidth { Unspecified, Short, Long, LongLong };
48
49 /// Specifies the signedness of a type, e.g., signed or unsigned.
50 enum class TypeSpecifierSign { Unspecified, Signed, Unsigned };
51
52 enum class TypeSpecifiersPipe { Unspecified, Pipe };
53
54 /// Specifies the kind of type.
55 enum TypeSpecifierType {
56 TST_unspecified,
57 TST_void,
58 TST_char,
59 TST_wchar, // C++ wchar_t
60 TST_char8, // C++20 char8_t (proposed)
61 TST_char16, // C++11 char16_t
62 TST_char32, // C++11 char32_t
63 TST_int,
64 TST_int128,
65 TST_bitint, // Bit-precise integer types.
66 TST_half, // OpenCL half, ARM NEON __fp16
67 TST_Float16, // C11 extension ISO/IEC TS 18661-3
68 TST_Accum, // ISO/IEC JTC1 SC22 WG14 N1169 Extension
69 TST_Fract,
70 TST_BFloat16,
71 TST_float,
72 TST_double,
73 TST_float128,
74 TST_ibm128,
75 TST_bool, // _Bool
76 TST_decimal32, // _Decimal32
77 TST_decimal64, // _Decimal64
78 TST_decimal128, // _Decimal128
79 TST_enum,
80 TST_union,
81 TST_struct,
82 TST_class, // C++ class type
83 TST_interface, // C++ (Microsoft-specific) __interface type
84 TST_typename, // Typedef, C++ class-name or enum name, etc.
85 TST_typeofType, // C23 (and GNU extension) typeof(type-name)
86 TST_typeofExpr, // C23 (and GNU extension) typeof(expression)
87 TST_typeof_unqualType, // C23 typeof_unqual(type-name)
88 TST_typeof_unqualExpr, // C23 typeof_unqual(expression)
89 TST_decltype, // C++11 decltype
90#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) TST_##Trait,
91#include "clang/Basic/TransformTypeTraits.def"
92 TST_auto, // C++11 auto
93 TST_decltype_auto, // C++1y decltype(auto)
94 TST_auto_type, // __auto_type extension
95 TST_unknown_anytype, // __unknown_anytype extension
96 TST_atomic, // C11 _Atomic
97 TST_typename_pack_indexing,
98#define GENERIC_IMAGE_TYPE(ImgType, Id) \
99 TST_##ImgType##_t, // OpenCL image types
100#include "clang/Basic/OpenCLImageTypes.def"
101 TST_error // erroneous type
102 };
103
104 /// Structure that packs information about the type specifiers that
105 /// were written in a particular type specifier sequence.
106 struct WrittenBuiltinSpecs {
107 static_assert(TST_error < 1 << 7, "Type bitfield not wide enough for TST");
108 LLVM_PREFERRED_TYPE(TypeSpecifierType)
109 unsigned Type : 7;
110 LLVM_PREFERRED_TYPE(TypeSpecifierSign)
111 unsigned Sign : 2;
112 LLVM_PREFERRED_TYPE(TypeSpecifierWidth)
113 unsigned Width : 2;
114 LLVM_PREFERRED_TYPE(bool)
115 unsigned ModeAttr : 1;
116 };
117
118 /// A C++ access specifier (public, private, protected), plus the
119 /// special value "none" which means different things in different contexts.
120 enum AccessSpecifier {
121 AS_public,
122 AS_protected,
123 AS_private,
124 AS_none
125 };
126
127 /// The categorization of expression values, currently following the
128 /// C++11 scheme.
129 enum ExprValueKind {
130 /// A pr-value expression (in the C++11 taxonomy)
131 /// produces a temporary value.
132 VK_PRValue,
133
134 /// An l-value expression is a reference to an object with
135 /// independent storage.
136 VK_LValue,
137
138 /// An x-value expression is a reference to an object with
139 /// independent storage but which can be "moved", i.e.
140 /// efficiently cannibalized for its resources.
141 VK_XValue
142 };
143
144 /// A further classification of the kind of object referenced by an
145 /// l-value or x-value.
146 enum ExprObjectKind {
147 /// An ordinary object is located at an address in memory.
148 OK_Ordinary,
149
150 /// A bitfield object is a bitfield on a C or C++ record.
151 OK_BitField,
152
153 /// A vector component is an element or range of elements on a vector.
154 OK_VectorComponent,
155
156 /// An Objective-C property is a logical field of an Objective-C
157 /// object which is read and written via Objective-C method calls.
158 OK_ObjCProperty,
159
160 /// An Objective-C array/dictionary subscripting which reads an
161 /// object or writes at the subscripted array/dictionary element via
162 /// Objective-C method calls.
163 OK_ObjCSubscript,
164
165 /// A matrix component is a single element of a matrix.
166 OK_MatrixComponent
167 };
168
169 /// The reason why a DeclRefExpr does not constitute an odr-use.
170 enum NonOdrUseReason {
171 /// This is an odr-use.
172 NOUR_None = 0,
173 /// This name appears in an unevaluated operand.
174 NOUR_Unevaluated,
175 /// This name appears as a potential result of an lvalue-to-rvalue
176 /// conversion that is a constant expression.
177 NOUR_Constant,
178 /// This name appears as a potential result of a discarded value
179 /// expression.
180 NOUR_Discarded,
181 };
182
183 /// Describes the kind of template specialization that a
184 /// particular template specialization declaration represents.
185 enum TemplateSpecializationKind {
186 /// This template specialization was formed from a template-id but
187 /// has not yet been declared, defined, or instantiated.
188 TSK_Undeclared = 0,
189 /// This template specialization was implicitly instantiated from a
190 /// template. (C++ [temp.inst]).
191 TSK_ImplicitInstantiation,
192 /// This template specialization was declared or defined by an
193 /// explicit specialization (C++ [temp.expl.spec]) or partial
194 /// specialization (C++ [temp.class.spec]).
195 TSK_ExplicitSpecialization,
196 /// This template specialization was instantiated from a template
197 /// due to an explicit instantiation declaration request
198 /// (C++11 [temp.explicit]).
199 TSK_ExplicitInstantiationDeclaration,
200 /// This template specialization was instantiated from a template
201 /// due to an explicit instantiation definition request
202 /// (C++ [temp.explicit]).
203 TSK_ExplicitInstantiationDefinition
204 };
205
206 /// Determine whether this template specialization kind refers
207 /// to an instantiation of an entity (as opposed to a non-template or
208 /// an explicit specialization).
209 inline bool isTemplateInstantiation(TemplateSpecializationKind Kind) {
210 return Kind != TSK_Undeclared && Kind != TSK_ExplicitSpecialization;
211 }
212
213 /// True if this template specialization kind is an explicit
214 /// specialization, explicit instantiation declaration, or explicit
215 /// instantiation definition.
216 inline bool isTemplateExplicitInstantiationOrSpecialization(
217 TemplateSpecializationKind Kind) {
218 switch (Kind) {
219 case TSK_ExplicitSpecialization:
220 case TSK_ExplicitInstantiationDeclaration:
221 case TSK_ExplicitInstantiationDefinition:
222 return true;
223
224 case TSK_Undeclared:
225 case TSK_ImplicitInstantiation:
226 return false;
227 }
228 llvm_unreachable("bad template specialization kind");
229 }
230
231 /// Thread storage-class-specifier.
232 enum ThreadStorageClassSpecifier {
233 TSCS_unspecified,
234 /// GNU __thread.
235 TSCS___thread,
236 /// C++11 thread_local. Implies 'static' at block scope, but not at
237 /// class scope.
238 TSCS_thread_local,
239 /// C11 _Thread_local. Must be combined with either 'static' or 'extern'
240 /// if used at block scope.
241 TSCS__Thread_local
242 };
243
244 /// Storage classes.
245 enum StorageClass {
246 // These are legal on both functions and variables.
247 SC_None,
248 SC_Extern,
249 SC_Static,
250 SC_PrivateExtern,
251
252 // These are only legal on variables.
253 SC_Auto,
254 SC_Register
255 };
256
257 /// Checks whether the given storage class is legal for functions.
258 inline bool isLegalForFunction(StorageClass SC) {
259 return SC <= SC_PrivateExtern;
260 }
261
262 /// Checks whether the given storage class is legal for variables.
263 inline bool isLegalForVariable(StorageClass SC) {
264 return true;
265 }
266
267 /// In-class initialization styles for non-static data members.
268 enum InClassInitStyle {
269 ICIS_NoInit, ///< No in-class initializer.
270 ICIS_CopyInit, ///< Copy initialization.
271 ICIS_ListInit ///< Direct list-initialization.
272 };
273
274 /// CallingConv - Specifies the calling convention that a function uses.
275 enum CallingConv {
276 CC_C, // __attribute__((cdecl))
277 CC_X86StdCall, // __attribute__((stdcall))
278 CC_X86FastCall, // __attribute__((fastcall))
279 CC_X86ThisCall, // __attribute__((thiscall))
280 CC_X86VectorCall, // __attribute__((vectorcall))
281 CC_X86Pascal, // __attribute__((pascal))
282 CC_Win64, // __attribute__((ms_abi))
283 CC_X86_64SysV, // __attribute__((sysv_abi))
284 CC_X86RegCall, // __attribute__((regcall))
285 CC_AAPCS, // __attribute__((pcs("aapcs")))
286 CC_AAPCS_VFP, // __attribute__((pcs("aapcs-vfp")))
287 CC_IntelOclBicc, // __attribute__((intel_ocl_bicc))
288 CC_SpirFunction, // default for OpenCL functions on SPIR target
289 CC_OpenCLKernel, // inferred for OpenCL kernels
290 CC_Swift, // __attribute__((swiftcall))
291 CC_SwiftAsync, // __attribute__((swiftasynccall))
292 CC_PreserveMost, // __attribute__((preserve_most))
293 CC_PreserveAll, // __attribute__((preserve_all))
294 CC_AArch64VectorCall, // __attribute__((aarch64_vector_pcs))
295 CC_AArch64SVEPCS, // __attribute__((aarch64_sve_pcs))
296 CC_AMDGPUKernelCall, // __attribute__((amdgpu_kernel))
297 CC_M68kRTD, // __attribute__((m68k_rtd))
298 CC_PreserveNone, // __attribute__((preserve_none))
299 };
300
301 /// Checks whether the given calling convention supports variadic
302 /// calls. Unprototyped calls also use the variadic call rules.
303 inline bool supportsVariadicCall(CallingConv CC) {
304 switch (CC) {
305 case CC_X86StdCall:
306 case CC_X86FastCall:
307 case CC_X86ThisCall:
308 case CC_X86RegCall:
309 case CC_X86Pascal:
310 case CC_X86VectorCall:
311 case CC_SpirFunction:
312 case CC_OpenCLKernel:
313 case CC_Swift:
314 case CC_SwiftAsync:
315 case CC_M68kRTD:
316 return false;
317 default:
318 return true;
319 }
320 }
321
322 /// The storage duration for an object (per C++ [basic.stc]).
323 enum StorageDuration {
324 SD_FullExpression, ///< Full-expression storage duration (for temporaries).
325 SD_Automatic, ///< Automatic storage duration (most local variables).
326 SD_Thread, ///< Thread storage duration.
327 SD_Static, ///< Static storage duration.
328 SD_Dynamic ///< Dynamic storage duration.
329 };
330
331 /// Describes the nullability of a particular type.
332 enum class NullabilityKind : uint8_t {
333 /// Values of this type can never be null.
334 NonNull = 0,
335 /// Values of this type can be null.
336 Nullable,
337 /// Whether values of this type can be null is (explicitly)
338 /// unspecified. This captures a (fairly rare) case where we
339 /// can't conclude anything about the nullability of the type even
340 /// though it has been considered.
341 Unspecified,
342 // Generally behaves like Nullable, except when used in a block parameter
343 // that was imported into a swift async method. There, swift will assume
344 // that the parameter can get null even if no error occurred. _Nullable
345 // parameters are assumed to only get null on error.
346 NullableResult,
347 };
348 /// Prints human-readable debug representation.
349 llvm::raw_ostream &operator<<(llvm::raw_ostream&, NullabilityKind);
350
351 /// Return true if \p L has a weaker nullability annotation than \p R. The
352 /// ordering is: Unspecified < Nullable < NonNull.
353 inline bool hasWeakerNullability(NullabilityKind L, NullabilityKind R) {
354 return uint8_t(L) > uint8_t(R);
355 }
356
357 /// Retrieve the spelling of the given nullability kind.
358 llvm::StringRef getNullabilitySpelling(NullabilityKind kind,
359 bool isContextSensitive = false);
360
361 /// Kinds of parameter ABI.
362 enum class ParameterABI {
363 /// This parameter uses ordinary ABI rules for its type.
364 Ordinary,
365
366 /// This parameter (which must have pointer type) is a Swift
367 /// indirect result parameter.
368 SwiftIndirectResult,
369
370 /// This parameter (which must have pointer-to-pointer type) uses
371 /// the special Swift error-result ABI treatment. There can be at
372 /// most one parameter on a given function that uses this treatment.
373 SwiftErrorResult,
374
375 /// This parameter (which must have pointer type) uses the special
376 /// Swift context-pointer ABI treatment. There can be at
377 /// most one parameter on a given function that uses this treatment.
378 SwiftContext,
379
380 /// This parameter (which must have pointer type) uses the special
381 /// Swift asynchronous context-pointer ABI treatment. There can be at
382 /// most one parameter on a given function that uses this treatment.
383 SwiftAsyncContext,
384 };
385
386 /// Assigned inheritance model for a class in the MS C++ ABI. Must match order
387 /// of spellings in MSInheritanceAttr.
388 enum class MSInheritanceModel {
389 Single = 0,
390 Multiple = 1,
391 Virtual = 2,
392 Unspecified = 3,
393 };
394
395 llvm::StringRef getParameterABISpelling(ParameterABI kind);
396
397 inline llvm::StringRef getAccessSpelling(AccessSpecifier AS) {
398 switch (AS) {
399 case AccessSpecifier::AS_public:
400 return "public";
401 case AccessSpecifier::AS_protected:
402 return "protected";
403 case AccessSpecifier::AS_private:
404 return "private";
405 case AccessSpecifier::AS_none:
406 return {};
407 }
408 llvm_unreachable("Unknown AccessSpecifier");
409 }
410} // end namespace clang
411
412#endif // LLVM_CLANG_BASIC_SPECIFIERS_H
413

source code of clang/include/clang/Basic/Specifiers.h