Replace custom alignment enforcement with LLVM_ALIGNAS.

This isn't perfect as it still assumes sizeof(void*) == alignof(void*),
but we can fix that when compiler support gets better.

Shrinks some Stmts that happen to inherit from Stmt and have a
SourceLocation as the first member (64 bit archs only).

llvm-svn: 233911

2 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index ba6fd2e103c..b4410538f76 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3103,10 +3103,10 @@ FunctionDecl::setDependentTemplateSpecialization(ASTContext &Context,
 DependentFunctionTemplateSpecializationInfo::
 DependentFunctionTemplateSpecializationInfo(const UnresolvedSetImpl &Ts,
                                       const TemplateArgumentListInfo &TArgs)
-  : AngleLocs(TArgs.getLAngleLoc(), TArgs.getRAngleLoc()) {
-
-  d.NumTemplates = Ts.size();
-  d.NumArgs = TArgs.size();
+  : NumTemplates(Ts.size()), NumArgs(TArgs.size()),
+    AngleLocs(TArgs.getLAngleLoc(), TArgs.getRAngleLoc()) {
+  static_assert(sizeof(*this) % llvm::AlignOf<void *>::Alignment == 0,
+                "Trailing data is unaligned!");
 
   FunctionTemplateDecl **TsArray =
     const_cast<FunctionTemplateDecl**>(getTemplates());
diff --git a/clang/lib/AST/DeclGroup.cpp b/clang/lib/AST/DeclGroup.cpp
index 9861f2278f9..512837fdf3f 100644
--- a/clang/lib/AST/DeclGroup.cpp
+++ b/clang/lib/AST/DeclGroup.cpp
@@ -18,6 +18,8 @@
 using namespace clang;
 
 DeclGroup* DeclGroup::Create(ASTContext &C, Decl **Decls, unsigned NumDecls) {
+  static_assert(sizeof(DeclGroup) % llvm::AlignOf<void *>::Alignment == 0,
+                "Trailing data is unaligned!");
   assert(NumDecls > 1 && "Invalid DeclGroup");
   unsigned Size = sizeof(DeclGroup) + sizeof(Decl*) * NumDecls;
   void* Mem = C.Allocate(Size, llvm::AlignOf<DeclGroup>::Alignment);