[PCH] Fix memory leak related to deserialized MacroInfo objects.

Deserialized MacroInfos were not destroyed and if their SmallVector did heap allocation,
it was leaked.

rdar://13768967

llvm-svn: 180771

1 files changed, 6 insertions, 3 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 3cd40eacf8a..50a0cb55f73 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -61,9 +61,12 @@ MacroInfo *Preprocessor::AllocateDeserializedMacroInfo(SourceLocation L,
                                                        unsigned SubModuleID) {
   LLVM_STATIC_ASSERT(llvm::AlignOf<MacroInfo>::Alignment >= sizeof(SubModuleID),
                      "alignment for MacroInfo is less than the ID");
-  MacroInfo *MI =
-      (MacroInfo*)BP.Allocate(sizeof(MacroInfo) + sizeof(SubModuleID),
-                              llvm::AlignOf<MacroInfo>::Alignment);
+  DeserializedMacroInfoChain *MIChain =
+      BP.Allocate<DeserializedMacroInfoChain>();
+  MIChain->Next = DeserialMIChainHead;
+  DeserialMIChainHead = MIChain;
+
+  MacroInfo *MI = &MIChain->MI;
   new (MI) MacroInfo(L);
   MI->FromASTFile = true;
   MI->setOwningModuleID(SubModuleID);