ExternalASTSource.cpp revision 6bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89 
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
25void ExternalASTSource::FindFileRegionDecls(FileID File, unsigned Offset,
26                                            unsigned Length,
27                                            SmallVectorImpl<Decl *> &Decls) {}
28
29void ExternalASTSource::CompleteRedeclChain(const Decl *D) {}
30
31void ExternalASTSource::CompleteType(TagDecl *Tag) {}
32
33void ExternalASTSource::CompleteType(ObjCInterfaceDecl *Class) {}
34
35void ExternalASTSource::ReadComments() {}
36
37void ExternalASTSource::StartedDeserializing() {}
38
39void ExternalASTSource::FinishedDeserializing() {}
40
41void ExternalASTSource::StartTranslationUnit(ASTConsumer *Consumer) {}
42
43void ExternalASTSource::PrintStats() { }
44
45bool ExternalASTSource::layoutRecordType(
46    const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
47    llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
48    llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
49    llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) {
50  return false;
51}
52
53Decl *ExternalASTSource::GetExternalDecl(uint32_t ID) {
54  return nullptr;
55}
56
57Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
58  return Selector();
59}
60
61uint32_t ExternalASTSource::GetNumExternalSelectors() {
62   return 0;
63}
64
65Stmt *ExternalASTSource::GetExternalDeclStmt(uint64_t Offset) {
66  return nullptr;
67}
68
69CXXBaseSpecifier *
70ExternalASTSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
71  return nullptr;
72}
73
74bool
75ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
76                                                  DeclarationName Name) {
77  return false;
78}
79
80void ExternalASTSource::completeVisibleDeclsMap(const DeclContext *DC) {
81}
82
83ExternalLoadResult
84ExternalASTSource::FindExternalLexicalDecls(const DeclContext *DC,
85                                            bool (*isKindWeWant)(Decl::Kind),
86                                         SmallVectorImpl<Decl*> &Result) {
87  return ELR_AlreadyLoaded;
88}
89
90void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const { }
91
92uint32_t ExternalASTSource::incrementGeneration(ASTContext &C) {
93  uint32_t OldGeneration = CurrentGeneration;
94
95  // Make sure the generation of the topmost external source for the context is
96  // incremented. That might not be us.
97  auto *P = C.getExternalSource();
98  if (P && P != this)
99    CurrentGeneration = P->incrementGeneration(C);
100  else {
101    // FIXME: Only bump the generation counter if the current generation number
102    // has been observed?
103    if (!++CurrentGeneration)
104      llvm::report_fatal_error("generation counter overflowed", false);
105  }
106
107  return OldGeneration;
108}
109