ExternalASTSource.cpp revision 288943 
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 "llvm/Support/ErrorHandling.h"
20
21using namespace clang;
22
23ExternalASTSource::~ExternalASTSource() { }
24
25llvm::Optional<ExternalASTSource::ASTSourceDescriptor>
26ExternalASTSource::getSourceDescriptor(unsigned ID) {
27  return None;
28}
29
30ExternalASTSource::ASTSourceDescriptor
31ExternalASTSource::getSourceDescriptor(const Module &M) {
32  return ASTSourceDescriptor();
33}
34
35void ExternalASTSource::FindFileRegionDecls(FileID File, unsigned Offset,
36                                            unsigned Length,
37                                            SmallVectorImpl<Decl *> &Decls) {}
38
39void ExternalASTSource::CompleteRedeclChain(const Decl *D) {}
40
41void ExternalASTSource::CompleteType(TagDecl *Tag) {}
42
43void ExternalASTSource::CompleteType(ObjCInterfaceDecl *Class) {}
44
45void ExternalASTSource::ReadComments() {}
46
47void ExternalASTSource::StartedDeserializing() {}
48
49void ExternalASTSource::FinishedDeserializing() {}
50
51void ExternalASTSource::StartTranslationUnit(ASTConsumer *Consumer) {}
52
53void ExternalASTSource::PrintStats() { }
54
55bool ExternalASTSource::layoutRecordType(
56    const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
57    llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
58    llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
59    llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) {
60  return false;
61}
62
63Decl *ExternalASTSource::GetExternalDecl(uint32_t ID) {
64  return nullptr;
65}
66
67Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
68  return Selector();
69}
70
71uint32_t ExternalASTSource::GetNumExternalSelectors() {
72   return 0;
73}
74
75Stmt *ExternalASTSource::GetExternalDeclStmt(uint64_t Offset) {
76  return nullptr;
77}
78
79CXXCtorInitializer **
80ExternalASTSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
81  return nullptr;
82}
83
84CXXBaseSpecifier *
85ExternalASTSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
86  return nullptr;
87}
88
89bool
90ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
91                                                  DeclarationName Name) {
92  return false;
93}
94
95void ExternalASTSource::completeVisibleDeclsMap(const DeclContext *DC) {
96}
97
98ExternalLoadResult
99ExternalASTSource::FindExternalLexicalDecls(const DeclContext *DC,
100                                            bool (*isKindWeWant)(Decl::Kind),
101                                         SmallVectorImpl<Decl*> &Result) {
102  return ELR_AlreadyLoaded;
103}
104
105void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const { }
106
107uint32_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