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