1 files changed, 30 insertions, 26 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 1bafc2a4c58..17669b441c1 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -525,13 +525,9 @@ IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
   // If this identifier is a macro, deserialize the macro
   // definition.
   if (hadMacroDefinition) {
-    SmallVector<MacroID, 4> MacroIDs;
-    while (uint32_t LocalID = ReadUnalignedLE32(d)) {
-      MacroIDs.push_back(Reader.getGlobalMacroID(F, LocalID));
-      DataLen -= 4;
-    }
     DataLen -= 4;
-    Reader.setIdentifierIsMacro(II, MacroIDs);
+    uint32_t LocalID = ReadUnalignedLE32(d);
+    Reader.addMacroIDForDeserialization(II, Reader.getGlobalMacroID(F,LocalID));
   }
 
   Reader.SetIdentifierInfo(ID, II);
@@ -1061,8 +1057,7 @@ bool ASTReader::ReadBlockAbbrevs(llvm::BitstreamCursor &Cursor,
   }
 }
 
-void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset,
-                                MacroInfo *Hint) {
+void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset) {
   llvm::BitstreamCursor &Stream = F.MacroCursor;
 
   // Keep track of where we are in the stream, then jump back there
@@ -1078,19 +1073,18 @@ void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset,
   // adding tokens.
   struct AddLoadedMacroInfoRAII {
     Preprocessor &PP;
-    MacroInfo *Hint;
     MacroInfo *MI;
     IdentifierInfo *II;
 
-    AddLoadedMacroInfoRAII(Preprocessor &PP, MacroInfo *Hint)
-      : PP(PP), Hint(Hint), MI(), II() { }
+    explicit AddLoadedMacroInfoRAII(Preprocessor &PP)
+      : PP(PP), MI(), II() { }
     ~AddLoadedMacroInfoRAII( ) {
       if (MI) {
         // Finally, install the macro.
-        PP.addLoadedMacroInfo(II, MI, Hint);
+        PP.addLoadedMacroInfo(II, MI);
       }
     }
-  } AddLoadedMacroInfo(PP, Hint);
+  } AddLoadedMacroInfo(PP);
 
   while (true) {
     unsigned Code = Stream.ReadCode();
@@ -1146,6 +1140,9 @@ void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset,
       SourceLocation Loc = ReadSourceLocation(F, Record, NextIndex);
       MacroInfo *MI = PP.AllocateMacroInfo(Loc);
       MI->setDefinitionEndLoc(ReadSourceLocation(F, Record, NextIndex));
+      bool isHeadMI = Record[NextIndex++];
+      MacroInfo *PrevMI = getMacro(getGlobalMacroID(F, Record[NextIndex++]));
+      MI->setPreviousDefinition(PrevMI);
 
       // Record this macro.
       MacrosLoaded[GlobalID - NUM_PREDEF_MACRO_IDS] = MI;
@@ -1230,9 +1227,11 @@ void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset,
       }
       MI->setHidden(Hidden);
 
-      // Make sure we install the macro once we're done.
-      AddLoadedMacroInfo.MI = MI;
-      AddLoadedMacroInfo.II = II;
+      if (isHeadMI) {
+        // Make sure we install the macro once we're done.
+        AddLoadedMacroInfo.MI = MI;
+        AddLoadedMacroInfo.II = II;
+      }
 
       // Remember that we saw this macro last so that we add the tokens that
       // form its body to it.
@@ -1341,10 +1340,13 @@ HeaderFileInfoTrait::ReadData(const internal_key_type, const unsigned char *d,
   return HFI;
 }
 
-void ASTReader::setIdentifierIsMacro(IdentifierInfo *II, ArrayRef<MacroID> IDs){
+void ASTReader::addMacroIDForDeserialization(IdentifierInfo *II, MacroID ID){
   II->setHadMacroDefinition(true);
   assert(NumCurrentElementsDeserializing > 0 &&"Missing deserialization guard");
-  PendingMacroIDs[II].append(IDs.begin(), IDs.end());
+  SmallVector<serialization::MacroID, 2> &MacroIDs = PendingMacroIDs[II];
+  assert(std::find(MacroIDs.begin(), MacroIDs.end(), ID) == MacroIDs.end() &&
+         "Already added the macro ID for deserialization");
+  MacroIDs.push_back(ID);
 }
 
 void ASTReader::ReadDefinedMacros() {
@@ -6160,7 +6162,7 @@ IdentifierID ASTReader::getGlobalIdentifierID(ModuleFile &M, unsigned LocalID) {
   return LocalID + I->second;
 }
 
-MacroInfo *ASTReader::getMacro(MacroID ID, MacroInfo *Hint) {
+MacroInfo *ASTReader::getMacro(MacroID ID) {
   if (ID == 0)
     return 0;
 
@@ -6176,7 +6178,7 @@ MacroInfo *ASTReader::getMacro(MacroID ID, MacroInfo *Hint) {
     assert(I != GlobalMacroMap.end() && "Corrupted global macro map");
     ModuleFile *M = I->second;
     unsigned Index = ID - M->BaseMacroID;
-    ReadMacroRecord(*M, M->MacroOffsets[Index], Hint);
+    ReadMacroRecord(*M, M->MacroOffsets[Index]);
   }
 
   return MacrosLoaded[ID];
@@ -6875,13 +6877,15 @@ void ASTReader::finishPendingActions() {
     PendingDeclChains.clear();
 
     // Load any pending macro definitions.
+    // Note that new macros may be added while deserializing a macro.
     for (unsigned I = 0; I != PendingMacroIDs.size(); ++I) {
-      // FIXME: std::move here
-      SmallVector<MacroID, 2> GlobalIDs = PendingMacroIDs.begin()[I].second;
-      MacroInfo *Hint = 0;
-      for (unsigned IDIdx = 0, NumIDs = GlobalIDs.size(); IDIdx !=  NumIDs;
-           ++IDIdx) {
-        Hint = getMacro(GlobalIDs[IDIdx], Hint);
+      PendingMacroIDsMap::iterator PMIt = PendingMacroIDs.begin() + I;
+      IdentifierInfo *II = PMIt->first;
+      SmallVector<serialization::MacroID, 2> MacroIDs;
+      MacroIDs.swap(PMIt->second);
+      for (SmallVectorImpl<serialization::MacroID>::iterator
+             MIt = MacroIDs.begin(), ME = MacroIDs.end(); MIt != ME; ++MIt) {
+        getMacro(*MIt);
       }
     }
     PendingMacroIDs.clear();