r206317 - AST: Respect alignment attributes on typedef'd arrays

[Justin Bogner]

Author: bogner
Date: Tue Apr 15 15:12:41 2014
New Revision: 206317

URL: http://llvm.org/viewvc/llvm-project?rev=206317&view=rev
Log:
AST: Respect alignment attributes on typedef'd arrays

When instantiating an array that has an alignment attribute on it, we
were looking through the array type and only considering the element
type for the resulting alignment. We need to make sure we take the
array's requirements into account too.

Modified:
    cfe/trunk/lib/AST/ASTContext.cpp
    cfe/trunk/test/Sema/attr-aligned.c

Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=206317&r1=206316&r2=206317&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Tue Apr 15 15:12:41 2014
@@ -1322,7 +1322,9 @@ CharUnits ASTContext::getDeclAlign(const
             Align = std::max(Align, Target->getLargeArrayAlign());
         }
 
-        // Walk through any array types while we're at it.
+        // Keep track of extra alignment requirements on the array itself, then
+        // work with the element type.
+        Align = std::max(Align, getPreferredTypeAlign(T.getTypePtr()));
         T = getBaseElementType(arrayType);
       }
       Align = std::max(Align, getPreferredTypeAlign(T.getTypePtr()));

Modified: cfe/trunk/test/Sema/attr-aligned.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-aligned.c?rev=206317&r1=206316&r2=206317&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-aligned.c (original)
+++ cfe/trunk/test/Sema/attr-aligned.c Tue Apr 15 15:12:41 2014
@@ -43,3 +43,14 @@ struct E { int member __attribute__((ali
 struct E e;
 char e1[__alignof__(e) == 2 ?: -1] = {0};
 char e2[__alignof__(e.member) == 2 ?: -1] = {0};
+
+typedef char overaligned_char __attribute__((aligned(16)));
+typedef overaligned_char array_with_overaligned_char[11];
+typedef char array_with_align_attr[11] __attribute__((aligned(16)));
+
+char f0[__alignof__(array_with_overaligned_char) == 16 ? 1 : -1] = { 0 };
+char f1[__alignof__(array_with_align_attr) == 16 ? 1 : -1] = { 0 };
+array_with_overaligned_char F2;
+char f2[__alignof__(F2) == 16 ? 1 : -1] = { 0 };
+array_with_align_attr F3;
+char f3[__alignof__(F3) == 16 ? 1 : -1] = { 0 };