[cfe-commits] r130795 - in /cfe/trunk: lib/AST/ASTContext.cpp lib/AST/RecordLayoutBuilder.cpp test/CodeGen/ms_struct-bitfield-1.c

[Fariborz Jahanian]

Author: fjahanian
Date: Tue May  3 17:07:14 2011
New Revision: 130795

URL: http://llvm.org/viewvc/llvm-project?rev=130795&view=rev
Log:
Only the first zero-length bitfield decides alignment of
the followup data member in an ms_struct struct.
// rdar:// 8823265


Modified:
    cfe/trunk/lib/AST/ASTContext.cpp
    cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
    cfe/trunk/test/CodeGen/ms_struct-bitfield-1.c

Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=130795&r1=130794&r2=130795&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Tue May  3 17:07:14 2011
@@ -546,7 +546,8 @@
 bool ASTContext::ZeroBitfieldFollowsBitfield(const FieldDecl *FD,
                                              const FieldDecl *LastFD) const {
   return (FD->isBitField() && LastFD && LastFD->isBitField() &&
-          FD->getBitWidth()-> EvaluateAsInt(*this).getZExtValue() == 0);
+          FD->getBitWidth()-> EvaluateAsInt(*this).getZExtValue() == 0 &&
+          LastFD->getBitWidth()-> EvaluateAsInt(*this).getZExtValue() != 0);
 
 }
 

Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/RecordLayoutBuilder.cpp?rev=130795&r1=130794&r2=130795&view=diff
==============================================================================
--- cfe/trunk/lib/AST/RecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/AST/RecordLayoutBuilder.cpp Tue May  3 17:07:14 2011
@@ -1359,9 +1359,11 @@
       std::pair<uint64_t, unsigned> FieldInfo = 
         Context.getTypeInfo(ZeroLengthBitfield->getType());
       unsigned ZeroLengthBitfieldAlignment = FieldInfo.second;
-      if (ZeroLengthBitfieldAlignment > FieldAlign)
+      // Ignore alignment of subsequent zero-length bitfields.
+      if ((ZeroLengthBitfieldAlignment > FieldAlign) || (FieldSize == 0))
         FieldAlign = ZeroLengthBitfieldAlignment;
-      ZeroLengthBitfield = 0;
+      if (FieldSize)
+        ZeroLengthBitfield = 0;
     }
   }
 

Modified: cfe/trunk/test/CodeGen/ms_struct-bitfield-1.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/ms_struct-bitfield-1.c?rev=130795&r1=130794&r2=130795&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/ms_struct-bitfield-1.c (original)
+++ cfe/trunk/test/CodeGen/ms_struct-bitfield-1.c Tue May  3 17:07:14 2011
@@ -43,3 +43,49 @@
 } ATTR t5;
 static int a5[(sizeof(t5) == 4) -1];
 
+struct
+{
+                   char foo : 4;
+                   short : 0;
+                   long  :0;
+                   char bar;
+} ATTR t6;
+static int a6[(sizeof(t6) == 4) -1];
+
+struct
+{
+                   char foo : 4;
+                   long  :0;
+                   short : 0;
+                   char bar;
+} ATTR t7;
+static int a7[(sizeof(t7) == 16) -1];
+
+struct
+{
+                   char foo : 4;
+                   short : 0;
+                   long  :0;
+                   char bar:7;
+} ATTR t8;
+static int a8[(sizeof(t8) == 4) -1];
+
+struct
+{
+                   char foo : 4;
+                   long  :0;
+                   short : 0;
+                   char bar: 8;
+} ATTR t9;
+static int a9[(sizeof(t9) == 16) -1];
+
+struct
+{
+                   char foo : 4;
+                   char : 0;
+                   short : 0;
+                   int : 0;
+                   long  :0;
+                   char bar;
+} ATTR t10;
+static int a10[(sizeof(t10) == 2) -1];