Use a ContinuousRangeMap to map from the global declaration ID in the

AST reader down to the AST file + local ID within that file, rather
than lamely walking the PCH chain. There's no actual functionality
change now, but this is cleaner and more general.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135548 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 13 insertions, 13 deletions

diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 61c3a5c2ff..9f3d7504c7 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2046,6 +2046,13 @@ ASTReader::ReadASTBlock(PerFileData &F) {
       }
       F.DeclOffsets = (const uint32_t *)BlobStart;
       F.LocalNumDecls = Record[0];
+        
+      // Introduce the global -> local mapping for declarations within this 
+      GlobalDeclMap.insert(std::make_pair(getTotalNumDecls() + 1, 
+                                          std::make_pair(&F, 
+                                                         -getTotalNumDecls())));
+      DeclsLoaded.resize(DeclsLoaded.size() + F.LocalNumDecls);
+      
       break;
 
     case TU_UPDATE_LEXICAL: {
@@ -2522,14 +2529,13 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
   }
 
   // Allocate space for loaded slocentries, identifiers, decls and types.
-  unsigned TotalNumIdentifiers = 0, TotalNumTypes = 0, TotalNumDecls = 0,
+  unsigned TotalNumIdentifiers = 0, TotalNumTypes = 0, 
            TotalNumPreallocatedPreprocessingEntities = 0, TotalNumMacroDefs = 0,
            TotalNumSelectors = 0;
   for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
     TotalNumSLocEntries += Chain[I]->LocalNumSLocEntries;
     TotalNumIdentifiers += Chain[I]->LocalNumIdentifiers;
     TotalNumTypes += Chain[I]->LocalNumTypes;
-    TotalNumDecls += Chain[I]->LocalNumDecls;
     TotalNumPreallocatedPreprocessingEntities +=
         Chain[I]->NumPreallocatedPreprocessingEntities;
     TotalNumMacroDefs += Chain[I]->LocalNumMacroDefinitions;
@@ -2537,7 +2543,6 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
   }
   IdentifiersLoaded.resize(TotalNumIdentifiers);
   TypesLoaded.resize(TotalNumTypes);
-  DeclsLoaded.resize(TotalNumDecls);
   MacroDefinitionsLoaded.resize(TotalNumMacroDefs);
   if (PP) {
     if (TotalNumIdentifiers > 0)
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 24ab544dcd..4f55d4625d 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1408,7 +1408,7 @@ static bool isConsumerInterestedIn(Decl *D) {
   return isa<ObjCProtocolDecl>(D) || isa<ObjCImplementationDecl>(D);
 }
 
-/// \brief Get the correct cursor and offset for loading a type.
+/// \brief Get the correct cursor and offset for loading a declaration.
 ASTReader::RecordLocation
 ASTReader::DeclCursorForIndex(unsigned Index, DeclID ID) {
   // See if there's an override.
@@ -1416,15 +1416,10 @@ ASTReader::DeclCursorForIndex(unsigned Index, DeclID ID) {
   if (It != ReplacedDecls.end())
     return RecordLocation(It->second.first, It->second.second);
 
-  PerFileData *F = 0;
-  for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
-    F = Chain[N - I - 1];
-    if (Index < F->LocalNumDecls)
-      break;
-    Index -= F->LocalNumDecls;
-  }
-  assert(F && F->LocalNumDecls > Index && "Broken chain");
-  return RecordLocation(F, F->DeclOffsets[Index]);
+  GlobalDeclMapType::iterator I = GlobalDeclMap.find(ID);
+  assert(I != GlobalDeclMap.end() && "Corrupted global declaration map");
+  return RecordLocation(I->second.first, 
+                        I->second.first->DeclOffsets[Index + I->second.second]);
 }
 
 void ASTDeclReader::attachPreviousDecl(Decl *D, Decl *previous) {