clang/lib/AST/ExternalASTSource.cpp

   1 //===- ExternalASTSource.cpp - Abstract External AST Interface ------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file provides the default implementation of the ExternalASTSource
  10 //  interface, which enables construction of AST nodes from some external
  11 //  source.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/AST/ExternalASTSource.h"
  16 #include "clang/AST/ASTContext.h"
  17 #include "clang/AST/DeclarationName.h"
  18 #include "clang/Basic/FileManager.h"
  19 #include "clang/Basic/IdentifierTable.h"
  20 #include "clang/Basic/LLVM.h"
  21 #include "clang/Basic/Module.h"
  22 #include "clang/Basic/SourceManager.h"
  23 #include "llvm/Support/ErrorHandling.h"
  24 #include <cstdint>
  25 #include <optional>
  26
  27 using namespace clang;
  28
  29 char ExternalASTSource::ID;
  30
  31 ExternalASTSource::~ExternalASTSource() = default;
  32
  33 std::optional<ASTSourceDescriptor>
  34 ExternalASTSource::getSourceDescriptor(unsigned ID) {
  35   return std::nullopt;
  36 }
  37
  38 ExternalASTSource::ExtKind
  39 ExternalASTSource::hasExternalDefinitions(const Decl *D) {
  40   return EK_ReplyHazy;
  41 }
  42
  43 void ExternalASTSource::FindFileRegionDecls(FileID File, unsigned Offset,
  44                                             unsigned Length,
  45                                             SmallVectorImpl<Decl *> &Decls) {}
  46
  47 void ExternalASTSource::CompleteRedeclChain(const Decl *D) {}
  48
  49 void ExternalASTSource::CompleteType(TagDecl *Tag) {}
  50
  51 void ExternalASTSource::CompleteType(ObjCInterfaceDecl *Class) {}
  52
  53 void ExternalASTSource::ReadComments() {}
  54
  55 void ExternalASTSource::StartedDeserializing() {}
  56
  57 void ExternalASTSource::FinishedDeserializing() {}
  58
  59 void ExternalASTSource::StartTranslationUnit(ASTConsumer *Consumer) {}
  60
  61 void ExternalASTSource::PrintStats() {}
  62
  63 bool ExternalASTSource::layoutRecordType(
  64     const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
  65     llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
  66     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
  67     llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) {
  68   return false;
  69 }
  70
  71 Decl *ExternalASTSource::GetExternalDecl(uint32_t ID) {
  72   return nullptr;
  73 }
  74
  75 Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
  76   return Selector();
  77 }
  78
  79 uint32_t ExternalASTSource::GetNumExternalSelectors() {
  80    return 0;
  81 }
  82
  83 Stmt *ExternalASTSource::GetExternalDeclStmt(uint64_t Offset) {
  84   return nullptr;
  85 }
  86
  87 CXXCtorInitializer **
  88 ExternalASTSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
  89   return nullptr;
  90 }
  91
  92 CXXBaseSpecifier *
  93 ExternalASTSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
  94   return nullptr;
  95 }
  96
  97 bool
  98 ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
  99                                                   DeclarationName Name) {
 100   return false;
 101 }
 102
 103 void ExternalASTSource::completeVisibleDeclsMap(const DeclContext *DC) {}
 104
 105 void ExternalASTSource::FindExternalLexicalDecls(
 106     const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
 107     SmallVectorImpl<Decl *> &Result) {}
 108
 109 void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const {}
 110
 111 uint32_t ExternalASTSource::incrementGeneration(ASTContext &C) {
 112   uint32_t OldGeneration = CurrentGeneration;
 113
 114   // Make sure the generation of the topmost external source for the context is
 115   // incremented. That might not be us.
 116   auto *P = C.getExternalSource();
 117   if (P && P != this)
 118     CurrentGeneration = P->incrementGeneration(C);
 119   else {
 120     // FIXME: Only bump the generation counter if the current generation number
 121     // has been observed?
 122     if (!++CurrentGeneration)
 123       llvm::report_fatal_error("generation counter overflowed", false);
 124   }
 125
 126   return OldGeneration;
 127 }