r251036 - [MS ABI] Don't crash when inheriting from base with trailing empty array member

[David Majnemer via cfe-commits]

Author: majnemer
Date: Thu Oct 22 13:04:22 2015
New Revision: 251036

URL: http://llvm.org/viewvc/llvm-project?rev=251036&view=rev
Log:
[MS ABI] Don't crash when inheriting from base with trailing empty array member

We got this right for Itanium but not MSVC because CGRecordLayoutBuilder
was checking if the base's size was zero when it should have been
checking the non-virtual size.

This fixes PR21040.

Modified:
    cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp
    cfe/trunk/test/Layout/ms-x86-empty-nonvirtual-bases.cpp

Modified: cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp?rev=251036&r1=251035&r2=251036&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp Thu Oct 22 13:04:22 2015
@@ -454,7 +454,7 @@ void CGRecordLowering::accumulateBases()
     // contain only a trailing array member.
     const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
     if (!BaseDecl->isEmpty() &&
-        !Context.getASTRecordLayout(BaseDecl).getSize().isZero())
+        !Context.getASTRecordLayout(BaseDecl).getNonVirtualSize().isZero())
       Members.push_back(MemberInfo(Layout.getBaseClassOffset(BaseDecl),
           MemberInfo::Base, getStorageType(BaseDecl), BaseDecl));
   }

Modified: cfe/trunk/test/Layout/ms-x86-empty-nonvirtual-bases.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Layout/ms-x86-empty-nonvirtual-bases.cpp?rev=251036&r1=251035&r2=251036&view=diff
==============================================================================
--- cfe/trunk/test/Layout/ms-x86-empty-nonvirtual-bases.cpp (original)
+++ cfe/trunk/test/Layout/ms-x86-empty-nonvirtual-bases.cpp Thu Oct 22 13:04:22 2015
@@ -159,6 +159,28 @@ struct __declspec(align(32)) H : B0, B1,
 // CHECK-NEXT:      | [sizeof=64, align=32
 // CHECK-NEXT:      |  nvsize=40, nvalign=32]
 
+struct I {
+  int i0[0];
+};
+
+// CHECK: *** Dumping AST Record Layout
+// CHECK-NEXT:    0 | struct I
+// CHECK-NEXT:    0 |   int [0] i0
+// CHECK-NEXT:      | [sizeof={{1|4}}, align=4,
+// CHECK-NEXT:      |  nvsize=0, nvalign=4]
+
+struct J : I {
+  int j;
+};
+
+// CHECK: *** Dumping AST Record Layout
+// CHECK-NEXT:   0 | struct J
+// CHECK-NEXT:   0 |   struct I (base)
+// CHECK-NEXT:   0 |     int [0] i0
+// CHECK-NEXT:   0 |   int j
+// CHECK-NEXT:     | [sizeof=4, align=4,
+// CHECK-NEXT:     |  nvsize=4, nvalign=4]
+
 int a[
 sizeof(A)+
 sizeof(B)+
@@ -167,4 +189,6 @@ sizeof(D)+
 sizeof(E)+
 sizeof(F)+
 sizeof(G)+
-sizeof(H)];
+sizeof(H)+
+sizeof(I)+
+sizeof(J)];