1 //===--- Linkage.h - Linkage enumeration and utilities ----------*- 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 the Linkage enumeration and various utility functions. 12 /// 13 //===----------------------------------------------------------------------===// 14 #ifndef LLVM_CLANG_BASIC_LINKAGE_H 15 #define LLVM_CLANG_BASIC_LINKAGE_H 16 17 namespace clang { 18 19 /// \brief Describes the different kinds of linkage 20 /// (C++ [basic.link], C99 6.2.2) that an entity may have. 21 enum Linkage { 22 /// \brief No linkage, which means that the entity is unique and 23 /// can only be referred to from within its scope. 24 NoLinkage = 0, 25 26 /// \brief Internal linkage, which indicates that the entity can 27 /// be referred to from within the translation unit (but not other 28 /// translation units). 29 InternalLinkage, 30 31 /// \brief External linkage within a unique namespace. 32 /// 33 /// From the language perspective, these entities have external 34 /// linkage. However, since they reside in an anonymous namespace, 35 /// their names are unique to this translation unit, which is 36 /// equivalent to having internal linkage from the code-generation 37 /// point of view. 38 UniqueExternalLinkage, 39 40 /// \brief External linkage, which indicates that the entity can 41 /// be referred to from other translation units. 42 ExternalLinkage 43 }; 44 45 /// \brief Describes the different kinds of language linkage 46 /// (C++ [dcl.link]) that an entity may have. 47 enum LanguageLinkage { 48 CLanguageLinkage, 49 CXXLanguageLinkage, 50 NoLanguageLinkage 51 }; 52 53 /// \brief A more specific kind of linkage than enum Linkage. 54 /// 55 /// This is relevant to CodeGen and AST file reading. 56 enum GVALinkage { 57 GVA_Internal, 58 GVA_C99Inline, 59 GVA_CXXInline, 60 GVA_StrongExternal, 61 GVA_TemplateInstantiation, 62 GVA_ExplicitTemplateInstantiation 63 }; 64 65 /// \brief Determine whether the given linkage is semantically external. 66 inline bool isExternalLinkage(Linkage L) { 67 return L == UniqueExternalLinkage || L == ExternalLinkage; 68 } 69 70 /// \brief Compute the minimum linkage given two linages. 71 inline Linkage minLinkage(Linkage L1, Linkage L2) { 72 return L1 < L2? L1 : L2; 73 } 74 75 } // end namespace clang 76 77 #endif // LLVM_CLANG_BASIC_LINKAGE_H 78
