1 //===- ExternalASTSource.cpp - Abstract External AST Interface --*- 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 //  This file provides the default implementation of the ExternalASTSource
11 //  interface, which enables construction of AST nodes from some external
12 //  source.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "clang/AST/ExternalASTSource.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclarationName.h"
19 #include "clang/Basic/Module.h"
20 #include "llvm/Support/ErrorHandling.h"
21 
22 using namespace clang;
23 
24 ExternalASTSource::~ExternalASTSource() { }
25 
26 llvm::Optional<ExternalASTSource::ASTSourceDescriptor>
27 ExternalASTSource::getSourceDescriptor(unsigned ID) {
28   return None;
29 }
30 
31 ExternalASTSource::ExtKind
32 ExternalASTSource::hasExternalDefinitions(unsigned ID) {
33   return EK_ReplyHazy;
34 }
35 
36 ExternalASTSource::ASTSourceDescriptor::ASTSourceDescriptor(const Module &M)
37   : Signature(M.Signature), ClangModule(&M) {
38   if (M.Directory)
39     Path = M.Directory->getName();
40   if (auto *File = M.getASTFile())
41     ASTFile = File->getName();
42 }
43 
44 std::string ExternalASTSource::ASTSourceDescriptor::getModuleName() const {
45   if (ClangModule)
46     return ClangModule->Name;
47   else
48     return PCHModuleName;
49 }
50 
51 void ExternalASTSource::FindFileRegionDecls(FileID File, unsigned Offset,
52                                             unsigned Length,
53                                             SmallVectorImpl<Decl *> &Decls) {}
54 
55 void ExternalASTSource::CompleteRedeclChain(const Decl *D) {}
56 
57 void ExternalASTSource::CompleteType(TagDecl *Tag) {}
58 
59 void ExternalASTSource::CompleteType(ObjCInterfaceDecl *Class) {}
60 
61 void ExternalASTSource::ReadComments() {}
62 
63 void ExternalASTSource::StartedDeserializing() {}
64 
65 void ExternalASTSource::FinishedDeserializing() {}
66 
67 void ExternalASTSource::StartTranslationUnit(ASTConsumer *Consumer) {}
68 
69 void ExternalASTSource::PrintStats() { }
70 
71 bool ExternalASTSource::layoutRecordType(
72     const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
73     llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
74     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
75     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) {
76   return false;
77 }
78 
79 Decl *ExternalASTSource::GetExternalDecl(uint32_t ID) {
80   return nullptr;
81 }
82 
83 Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
84   return Selector();
85 }
86 
87 uint32_t ExternalASTSource::GetNumExternalSelectors() {
88    return 0;
89 }
90 
91 Stmt *ExternalASTSource::GetExternalDeclStmt(uint64_t Offset) {
92   return nullptr;
93 }
94 
95 CXXCtorInitializer **
96 ExternalASTSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
97   return nullptr;
98 }
99 
100 CXXBaseSpecifier *
101 ExternalASTSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
102   return nullptr;
103 }
104 
105 bool
106 ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
107                                                   DeclarationName Name) {
108   return false;
109 }
110 
111 void ExternalASTSource::completeVisibleDeclsMap(const DeclContext *DC) {}
112 
113 void ExternalASTSource::FindExternalLexicalDecls(
114     const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
115     SmallVectorImpl<Decl *> &Result) {}
116 
117 void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const {}
118 
119 uint32_t ExternalASTSource::incrementGeneration(ASTContext &C) {
120   uint32_t OldGeneration = CurrentGeneration;
121 
122   // Make sure the generation of the topmost external source for the context is
123   // incremented. That might not be us.
124   auto *P = C.getExternalSource();
125   if (P && P != this)
126     CurrentGeneration = P->incrementGeneration(C);
127   else {
128     // FIXME: Only bump the generation counter if the current generation number
129     // has been observed?
130     if (!++CurrentGeneration)
131       llvm::report_fatal_error("generation counter overflowed", false);
132   }
133 
134   return OldGeneration;
135 }
136