Fix overallocation and underalignment of ASTTemplateArgumentListInfo objects.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161918 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 16 insertions, 10 deletions

diff --git a/include/clang/AST/TemplateBase.h b/include/clang/AST/TemplateBase.h
index 54c9f2c534..5047028e5e 100644
--- a/include/clang/AST/TemplateBase.h
+++ b/include/clang/AST/TemplateBase.h
@@ -510,17 +510,23 @@ public:
 /// This is safe to be used inside an AST node, in contrast with
 /// TemplateArgumentListInfo.
 struct ASTTemplateArgumentListInfo {
-  /// \brief The source location of the left angle bracket ('<');
+  /// \brief The source location of the left angle bracket ('<').
   SourceLocation LAngleLoc;
   
-  /// \brief The source location of the right angle bracket ('>');
+  /// \brief The source location of the right angle bracket ('>').
   SourceLocation RAngleLoc;
   
-  /// \brief The number of template arguments in TemplateArgs.
-  /// The actual template arguments (if any) are stored after the
-  /// ExplicitTemplateArgumentList structure.
-  unsigned NumTemplateArgs;
-  
+  union {
+    /// \brief The number of template arguments in TemplateArgs.
+    /// The actual template arguments (if any) are stored after the
+    /// ExplicitTemplateArgumentList structure.
+    unsigned NumTemplateArgs;
+
+    /// Force ASTTemplateArgumentListInfo to the right alignment
+    /// for the following array of TemplateArgumentLocs.
+    void *Aligner;
+  };
+
   /// \brief Retrieve the template arguments
   TemplateArgumentLoc *getTemplateArgs() {
     return reinterpret_cast<TemplateArgumentLoc *> (this + 1);
diff --git a/lib/AST/TemplateBase.cpp b/lib/AST/TemplateBase.cpp
index f8dd396d92..95ff4edf1d 100644
--- a/lib/AST/TemplateBase.cpp
+++ b/lib/AST/TemplateBase.cpp
@@ -556,8 +556,7 @@ const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
 const ASTTemplateArgumentListInfo *
 ASTTemplateArgumentListInfo::Create(ASTContext &C,
                                     const TemplateArgumentListInfo &List) {
-  std::size_t size = sizeof(CXXDependentScopeMemberExpr) +
-                     ASTTemplateArgumentListInfo::sizeFor(List.size());
+  std::size_t size = ASTTemplateArgumentListInfo::sizeFor(List.size());
   void *Mem = C.Allocate(size, llvm::alignOf<ASTTemplateArgumentListInfo>());
   ASTTemplateArgumentListInfo *TAI = new (Mem) ASTTemplateArgumentListInfo();
   TAI->initializeFrom(List);
@@ -642,6 +641,7 @@ ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc) {
 std::size_t
 ASTTemplateKWAndArgsInfo::sizeFor(unsigned NumTemplateArgs) {
   // Add space for the template keyword location.
+  // FIXME: There's room for this in the padding before the template args in
+  //        64-bit builds.
   return Base::sizeFor(NumTemplateArgs) + sizeof(SourceLocation);
 }
-