Use a ContinuousRangeMap to map from the global macro definition ID in

the AST reader down to the AST file + local ID, rather than walking
the PCH chain. More cleanup/generalization, although there is more
work to do for preprocessed entities. In particular, the
"preallocation" scheme for preprocessed entities is not going to work
well with late loading of PCH files, and it's likely we'll have to do
something akin to the SourceManager's negative/positive loading.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135556 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 28 insertions, 16 deletions

diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 72bfb0f8a4..c7bded06ad 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -582,6 +582,15 @@ private:
   /// \brief The macro definitions we have already loaded.
   llvm::SmallVector<MacroDefinition *, 16> MacroDefinitionsLoaded;
 
+  typedef ContinuousRangeMap<serialization::MacroID, 
+                             std::pair<PerFileData *, int32_t>, 4> 
+    GlobalMacroDefinitionMapType;
+  
+  /// \brief Mapping from global macro definition IDs to the module in which the
+  /// selector resides along with the offset that should be added to the
+  /// global selector ID to produce a local ID.
+  GlobalMacroDefinitionMapType GlobalMacroDefinitionMap;
+
   /// \brief Mapping from identifiers that represent macros whose definitions
   /// have not yet been deserialized to the global offset where the macro
   /// record resides.
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 3bb9177011..f31fb751ab 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1833,18 +1833,14 @@ MacroDefinition *ASTReader::getMacroDefinition(MacroID ID) {
     return 0;
 
   if (!MacroDefinitionsLoaded[ID - 1]) {
-    unsigned Index = ID - 1;
-    for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
-      PerFileData &F = *Chain[N - I - 1];
-      if (Index < F.LocalNumMacroDefinitions) {
-        SavedStreamPosition SavedPosition(F.PreprocessorDetailCursor);  
-        F.PreprocessorDetailCursor.JumpToBit(F.MacroDefinitionOffsets[Index]);
-        LoadPreprocessedEntity(F);
-        break;
-      }
-      Index -= F.LocalNumMacroDefinitions;
-    }
-    assert(MacroDefinitionsLoaded[ID - 1] && "Broken chain");
+    GlobalMacroDefinitionMapType::iterator I =GlobalMacroDefinitionMap.find(ID);
+    assert(I != GlobalMacroDefinitionMap.end() && 
+           "Corrupted global macro definition map");
+    PerFileData &F = *I->second.first;
+    unsigned Index = ID - 1 + I->second.second;
+    SavedStreamPosition SavedPosition(F.PreprocessorDetailCursor);  
+    F.PreprocessorDetailCursor.JumpToBit(F.MacroDefinitionOffsets[Index]);
+    LoadPreprocessedEntity(F);
   }
 
   return MacroDefinitionsLoaded[ID - 1];
@@ -2357,6 +2353,16 @@ ASTReader::ReadASTBlock(PerFileData &F) {
       F.MacroDefinitionOffsets = (const uint32_t *)BlobStart;
       F.NumPreallocatedPreprocessingEntities = Record[0];
       F.LocalNumMacroDefinitions = Record[1];
+        
+      // Introduce the global -> local mapping for identifiers within this AST
+      // file
+      GlobalMacroDefinitionMap.insert(
+               std::make_pair(getTotalNumMacroDefinitions() + 1, 
+                              std::make_pair(&F, 
+                                             -getTotalNumMacroDefinitions())));
+      MacroDefinitionsLoaded.resize(
+                    MacroDefinitionsLoaded.size() + F.LocalNumMacroDefinitions);
+
       break;
 
     case DECL_UPDATE_OFFSETS: {
@@ -2545,17 +2551,14 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
   }
 
   // Allocate space for loaded slocentries, identifiers, decls and types.
-  unsigned TotalNumTypes = 0, 
-           TotalNumPreallocatedPreprocessingEntities = 0, TotalNumMacroDefs = 0;
+  unsigned TotalNumTypes = 0, TotalNumPreallocatedPreprocessingEntities = 0;
   for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
     TotalNumSLocEntries += Chain[I]->LocalNumSLocEntries;
     TotalNumTypes += Chain[I]->LocalNumTypes;
     TotalNumPreallocatedPreprocessingEntities +=
         Chain[I]->NumPreallocatedPreprocessingEntities;
-    TotalNumMacroDefs += Chain[I]->LocalNumMacroDefinitions;
   }
   TypesLoaded.resize(TotalNumTypes);
-  MacroDefinitionsLoaded.resize(TotalNumMacroDefs);
   if (PP) {
     PP->getHeaderSearchInfo().SetExternalLookup(this);
     if (TotalNumPreallocatedPreprocessingEntities > 0) {