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::ASTSourceDescriptor::ASTSourceDescriptor(const Module &M)
32   : Signature(M.Signature), ClangModule(&M) {
33   if (M.Directory)
34     Path = M.Directory->getName();
35   if (auto *File = M.getASTFile())
36     ASTFile = File->getName();
37 }
38 
39 std::string ExternalASTSource::ASTSourceDescriptor::getModuleName() const {
40   if (ClangModule)
41     return ClangModule->Name;
42   else
43     return PCHModuleName;
44 }
45 
46 void ExternalASTSource::FindFileRegionDecls(FileID File, unsigned Offset,
47                                             unsigned Length,
48                                             SmallVectorImpl<Decl *> &Decls) {}
49 
50 void ExternalASTSource::CompleteRedeclChain(const Decl *D) {}
51 
52 void ExternalASTSource::CompleteType(TagDecl *Tag) {}
53 
54 void ExternalASTSource::CompleteType(ObjCInterfaceDecl *Class) {}
55 
56 void ExternalASTSource::ReadComments() {}
57 
58 void ExternalASTSource::StartedDeserializing() {}
59 
60 void ExternalASTSource::FinishedDeserializing() {}
61 
62 void ExternalASTSource::StartTranslationUnit(ASTConsumer *Consumer) {}
63 
64 void ExternalASTSource::PrintStats() { }
65 
66 bool ExternalASTSource::layoutRecordType(
67     const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
68     llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
69     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
70     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) {
71   return false;
72 }
73 
74 Decl *ExternalASTSource::GetExternalDecl(uint32_t ID) {
75   return nullptr;
76 }
77 
78 Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
79   return Selector();
80 }
81 
82 uint32_t ExternalASTSource::GetNumExternalSelectors() {
83    return 0;
84 }
85 
86 Stmt *ExternalASTSource::GetExternalDeclStmt(uint64_t Offset) {
87   return nullptr;
88 }
89 
90 CXXCtorInitializer **
91 ExternalASTSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
92   return nullptr;
93 }
94 
95 CXXBaseSpecifier *
96 ExternalASTSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
97   return nullptr;
98 }
99 
100 bool
101 ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
102                                                   DeclarationName Name) {
103   return false;
104 }
105 
106 void ExternalASTSource::completeVisibleDeclsMap(const DeclContext *DC) {}
107 
108 void ExternalASTSource::FindExternalLexicalDecls(
109     const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
110     SmallVectorImpl<Decl *> &Result) {}
111 
112 void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const {}
113 
114 uint32_t ExternalASTSource::incrementGeneration(ASTContext &C) {
115   uint32_t OldGeneration = CurrentGeneration;
116 
117   // Make sure the generation of the topmost external source for the context is
118   // incremented. That might not be us.
119   auto *P = C.getExternalSource();
120   if (P && P != this)
121     CurrentGeneration = P->incrementGeneration(C);
122   else {
123     // FIXME: Only bump the generation counter if the current generation number
124     // has been observed?
125     if (!++CurrentGeneration)
126       llvm::report_fatal_error("generation counter overflowed", false);
127   }
128 
129   return OldGeneration;
130 }
131