[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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@251036 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index f91ecebd09262d5bdc7e891fe3ff0a55c8671087..375b59c5cb3391d1143702e448d42e363ff65156 100644 (file)
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -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));
   }

diff --git a/test/Layout/ms-x86-empty-nonvirtual-bases.cpp b/test/Layout/ms-x86-empty-nonvirtual-bases.cpp
index 00906e986279ba43a20fb59d7aefc5e6ec39b547..07be1d836ec5fe0991390387618e9a054a5757a0 100644 (file)
--- a/test/Layout/ms-x86-empty-nonvirtual-bases.cpp
+++ b/test/Layout/ms-x86-empty-nonvirtual-bases.cpp
@@ -159,6 +159,28 @@ struct __declspec(align(32)) H : B0, B1, B2, B3, B4 {
 // 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)];