commit 5fe61c6cb09a5a2d2ecddfb74f8b253d9d462165
author Eli Friedman <eli.friedman@gmail.com> Fri Mar 30 03:55:31 2012 +0000
committer Eli Friedman <eli.friedman@gmail.com> Fri Mar 30 03:55:31 2012 +0000
tree 0f3d269e500a9c76675a400212ef76b2da5ab048
parent 38ac243e300798e8cd9fe05888cd97beabfb94e6

ConstStructBuilder: fix offset math for base classes so it works correctly in general.  Found by inspection.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153720 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGExprConstant.cpp

diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index fb019f4..60cb4c5 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -469,21 +469,17 @@
 
     for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
       BaseInfo &Base = Bases[I];
-      // Build the base class subobject at the appropriately-offset location
-      // within this object.
-      NextFieldOffsetInChars -= Base.Offset;
 
       bool IsPrimaryBase = Layout.getPrimaryBase() == Base.Decl;
       Build(Val.getStructBase(Base.Index), Base.Decl, IsPrimaryBase,
             VTable, VTableClass, Offset + Base.Offset);
-
-      NextFieldOffsetInChars += Base.Offset;
     }
   }
 
   unsigned FieldNo = 0;
   const FieldDecl *LastFD = 0;
   bool IsMsStruct = RD->hasAttr<MsStructAttr>();
+  uint64_t OffsetBits = CGM.getContext().toBits(Offset);
 
   for (RecordDecl::field_iterator Field = RD->field_begin(),
        FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
@@ -516,10 +512,10 @@
 
     if (!Field->isBitField()) {
       // Handle non-bitfield members.
-      AppendField(*Field, Layout.getFieldOffset(FieldNo), EltInit);
+      AppendField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits, EltInit);
     } else {
       // Otherwise we have a bitfield.
-      AppendBitField(*Field, Layout.getFieldOffset(FieldNo),
+      AppendBitField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
                      cast<llvm::ConstantInt>(EltInit));
     }
   }

test/CodeGenCXX/const-init-cxx11.cpp

diff --git a/test/CodeGenCXX/const-init-cxx11.cpp b/test/CodeGenCXX/const-init-cxx11.cpp
index 8d92b81..c6250c6 100644
--- a/test/CodeGenCXX/const-init-cxx11.cpp
+++ b/test/CodeGenCXX/const-init-cxx11.cpp
@@ -78,6 +78,11 @@
   struct Test2 : X<E,0>, X<E,1>, X<E,2>, X<E,3> {};
   // CHECK: @_ZN9BaseClass2t2E = constant {{.*}} undef
   extern constexpr Test2 t2 = Test2();
+
+  struct __attribute((packed)) PackedD { double y = 2; };
+  struct Test3 : C, PackedD { constexpr Test3() {} };
+  // CHECK: @_ZN9BaseClass2t3E = constant <{ i8, double }> <{ i8 1, double 2.000000e+00 }>
+  extern constexpr Test3 t3 = Test3();
 }
 
 namespace Array {