1 //===- ASTCommon.h - Common stuff for ASTReader/ASTWriter -*- 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 //  This file defines common functions that both ASTReader and ASTWriter use.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LIB_SERIALIZATION_ASTCOMMON_H
14 #define LLVM_CLANG_LIB_SERIALIZATION_ASTCOMMON_H
15 
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/DeclFriend.h"
18 #include "clang/Serialization/ASTBitCodes.h"
19 
20 namespace clang {
21 
22 namespace serialization {
23 
24 enum DeclUpdateKind {
25   UPD_CXX_ADDED_IMPLICIT_MEMBER,
26   UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
27   UPD_CXX_ADDED_ANONYMOUS_NAMESPACE,
28   UPD_CXX_ADDED_FUNCTION_DEFINITION,
29   UPD_CXX_ADDED_VAR_DEFINITION,
30   UPD_CXX_POINT_OF_INSTANTIATION,
31   UPD_CXX_INSTANTIATED_CLASS_DEFINITION,
32   UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT,
33   UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER,
34   UPD_CXX_RESOLVED_DTOR_DELETE,
35   UPD_CXX_RESOLVED_EXCEPTION_SPEC,
36   UPD_CXX_DEDUCED_RETURN_TYPE,
37   UPD_DECL_MARKED_USED,
38   UPD_MANGLING_NUMBER,
39   UPD_STATIC_LOCAL_NUMBER,
40   UPD_DECL_MARKED_OPENMP_THREADPRIVATE,
41   UPD_DECL_MARKED_OPENMP_ALLOCATE,
42   UPD_DECL_MARKED_OPENMP_DECLARETARGET,
43   UPD_DECL_EXPORTED,
44   UPD_ADDED_ATTR_TO_RECORD
45 };
46 
47 TypeIdx TypeIdxFromBuiltin(const BuiltinType *BT);
48 
49 template <typename IdxForTypeTy>
50 TypeID MakeTypeID(ASTContext &Context, QualType T, IdxForTypeTy IdxForType) {
51   if (T.isNull())
52     return PREDEF_TYPE_NULL_ID;
53 
54   unsigned FastQuals = T.getLocalFastQualifiers();
55   T.removeLocalFastQualifiers();
56 
57   if (T.hasLocalNonFastQualifiers())
58     return IdxForType(T).asTypeID(FastQuals);
59 
60   assert(!T.hasLocalQualifiers());
61 
62   if (const BuiltinType *BT = dyn_cast<BuiltinType>(T.getTypePtr()))
63     return TypeIdxFromBuiltin(BT).asTypeID(FastQuals);
64 
65   if (T == Context.AutoDeductTy)
66     return TypeIdx(PREDEF_TYPE_AUTO_DEDUCT).asTypeID(FastQuals);
67   if (T == Context.AutoRRefDeductTy)
68     return TypeIdx(PREDEF_TYPE_AUTO_RREF_DEDUCT).asTypeID(FastQuals);
69 
70   return IdxForType(T).asTypeID(FastQuals);
71 }
72 
73 unsigned ComputeHash(Selector Sel);
74 
75 /// Retrieve the "definitive" declaration that provides all of the
76 /// visible entries for the given declaration context, if there is one.
77 ///
78 /// The "definitive" declaration is the only place where we need to look to
79 /// find information about the declarations within the given declaration
80 /// context. For example, C++ and Objective-C classes, C structs/unions, and
81 /// Objective-C protocols, categories, and extensions are all defined in a
82 /// single place in the source code, so they have definitive declarations
83 /// associated with them. C++ namespaces, on the other hand, can have
84 /// multiple definitions.
85 const DeclContext *getDefinitiveDeclContext(const DeclContext *DC);
86 
87 /// Determine whether the given declaration kind is redeclarable.
88 bool isRedeclarableDeclKind(unsigned Kind);
89 
90 /// Determine whether the given declaration needs an anonymous
91 /// declaration number.
92 bool needsAnonymousDeclarationNumber(const NamedDecl *D);
93 
94 /// Visit each declaration within \c DC that needs an anonymous
95 /// declaration number and call \p Visit with the declaration and its number.
96 template<typename Fn> void numberAnonymousDeclsWithin(const DeclContext *DC,
97                                                       Fn Visit) {
98   unsigned Index = 0;
99   for (Decl *LexicalD : DC->decls()) {
100     // For a friend decl, we care about the declaration within it, if any.
101     if (auto *FD = dyn_cast<FriendDecl>(LexicalD))
102       LexicalD = FD->getFriendDecl();
103 
104     auto *ND = dyn_cast_or_null<NamedDecl>(LexicalD);
105     if (!ND || !needsAnonymousDeclarationNumber(ND))
106       continue;
107 
108     Visit(ND, Index++);
109   }
110 }
111 
112 /// Determine whether the given declaration will be included in the per-module
113 /// initializer if it needs to be eagerly handed to the AST consumer. If so, we
114 /// should not hand it to the consumer when deserializing it, nor include it in
115 /// the list of eagerly deserialized declarations.
116 inline bool isPartOfPerModuleInitializer(const Decl *D) {
117   if (isa<ImportDecl>(D))
118     return true;
119   // Template instantiations are notionally in an "instantiation unit" rather
120   // than in any particular translation unit, so they need not be part of any
121   // particular (sub)module's per-module initializer.
122   if (auto *VD = dyn_cast<VarDecl>(D))
123     return !isTemplateInstantiation(VD->getTemplateSpecializationKind());
124   return false;
125 }
126 
127 } // namespace serialization
128 
129 } // namespace clang
130 
131 #endif
132