More VTT builder fixes. With these fixes we now correctly handle the very complex VTT example from the Itanium ABI spec.

llvm-svn: 93725
diff --git a/clang/test/CodeGenCXX/vtt-layout.cpp b/clang/test/CodeGenCXX/vtt-layout.cpp
index 1e78c90..d7d4227 100644
--- a/clang/test/CodeGenCXX/vtt-layout.cpp
+++ b/clang/test/CodeGenCXX/vtt-layout.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s
 
+// Test1::B should just have a single entry in its VTT, which points to the vtable.
 namespace Test1 {
 struct A { };
 
@@ -10,9 +11,7 @@
 void B::f() { } 
 }
 
-// Test1::B should just have a single entry in its VTT, which points to the vtable.
-// CHECK: @_ZTTN5Test11BE = constant [1 x i8*] [i8* bitcast (i8** getelementptr inbounds ([4 x i8*]* @_ZTVN5Test11BE, i64 0, i64 3) to i8*)]
-
+// Check that we don't add a secondary virtual pointer for Test2::A, since Test2::A doesn't have any virtual member functions or bases.
 namespace Test2 {
   struct A { };
 
@@ -22,5 +21,44 @@
   C c;
 }
 
-// Check that we don't add a secondary virtual pointer for Test2::A, since Test2::A doesn't have any virtual member functions or bases.
+// This is the sample from the C++ Itanium ABI, p2.6.2.
+namespace Test3 {
+  class A1 { int i; };
+  class A2 { int i; virtual void f(); };
+  class V1 : public A1, public A2 { int i; };
+  class B1 { int i; };
+  class B2 { int i; };
+  class V2 : public B1, public B2, public virtual V1 { int i; };
+  class V3 {virtual void g(); };
+  class C1 : public virtual V1 { int i; };
+  class C2 : public virtual V3, virtual V2 { int i; };
+  class X1 { int i; };
+  class C3 : public X1 { int i; };
+  class D : public C1, public C2, public C3 { int i;  };
+  
+  D d;
+}
+
+// This is the sample from the C++ Itanium ABI, p2.6.2, with the change suggested
+// (making A2 a virtual base of V1)
+namespace Test4 {
+  class A1 { int i; };
+  class A2 { int i; virtual void f(); };
+  class V1 : public A1, public virtual A2 { int i; };
+  class B1 { int i; };
+  class B2 { int i; };
+  class V2 : public B1, public B2, public virtual V1 { int i; };
+  class V3 {virtual void g(); };
+  class C1 : public virtual V1 { int i; };
+  class C2 : public virtual V3, virtual V2 { int i; };
+  class X1 { int i; };
+  class C3 : public X1 { int i; };
+  class D : public C1, public C2, public C3 { int i;  };
+  
+  D d;
+}
+
+// CHECK: @_ZTTN5Test11BE = constant [1 x i8*] [i8* bitcast (i8** getelementptr inbounds ([4 x i8*]* @_ZTVN5Test11BE, i64 0, i64 3) to i8*)]
+// CHECK: @_ZTTN5Test41DE = weak_odr constant [19 x i8*] [i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 0, i64 6) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE0_NS_2C1E, i64 0, i64 4) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE0_NS_2C1E, i64 0, i64 7) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE0_NS_2C1E, i64 0, i64 10) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTCN5Test41DE16_NS_2C2E, i64 0, i64 7) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTCN5Test41DE16_NS_2C2E, i64 0, i64 7) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTCN5Test41DE16_NS_2C2E, i64 0, i64 12) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTCN5Test41DE16_NS_2C2E, i64 0, i64 15) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTCN5Test41DE16_NS_2C2E, i64 0, i64 18) to i8*), i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 0, i64 17) to i8*), i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 0, i64 20) to i8*), i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 0, i64 13) to i8*), i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 0, i64 13) to i8*), i8* bitcast (i8** getelementptr inbounds ([25 x i8*]* @_ZTVN5Test41DE, i64 1, i64 0) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test41DE40_NS_2V1E, i64 0, i64 3) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test41DE40_NS_2V1E, i64 0, i64 6) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE72_NS_2V2E, i64 0, i64 4) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE72_NS_2V2E, i64 0, i64 7) to i8*), i8* bitcast (i8** getelementptr inbounds ([11 x i8*]* @_ZTCN5Test41DE72_NS_2V2E, i64 0, i64 10) to i8*)] ; <[19 x i8*]*> [#uses=4]
+// CHECK: @_ZTTN5Test31DE = weak_odr constant [13 x i8*] [i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTVN5Test31DE, i64 0, i64 5) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test31DE0_NS_2C1E, i64 0, i64 3) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test31DE0_NS_2C1E, i64 0, i64 6) to i8*), i8* bitcast (i8** getelementptr inbounds ([14 x i8*]* @_ZTCN5Test31DE16_NS_2C2E, i64 0, i64 6) to i8*), i8* bitcast (i8** getelementptr inbounds ([14 x i8*]* @_ZTCN5Test31DE16_NS_2C2E, i64 0, i64 6) to i8*), i8* bitcast (i8** getelementptr inbounds ([14 x i8*]* @_ZTCN5Test31DE16_NS_2C2E, i64 0, i64 10) to i8*), i8* bitcast (i8** getelementptr inbounds ([14 x i8*]* @_ZTCN5Test31DE16_NS_2C2E, i64 0, i64 13) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTVN5Test31DE, i64 0, i64 15) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTVN5Test31DE, i64 0, i64 11) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTVN5Test31DE, i64 0, i64 11) to i8*), i8* bitcast (i8** getelementptr inbounds ([19 x i8*]* @_ZTVN5Test31DE, i64 1, i64 0) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test31DE64_NS_2V2E, i64 0, i64 3) to i8*), i8* bitcast (i8** getelementptr inbounds ([7 x i8*]* @_ZTCN5Test31DE64_NS_2V2E, i64 0, i64 6) to i8*)] ; <[13 x i8*]*> [#uses=3]
 // CHECK: @_ZTTN5Test21CE = weak_odr constant [2 x i8*] [i8* bitcast (i8** getelementptr inbounds ([5 x i8*]* @_ZTVN5Test21CE, i64 0, i64 4) to i8*), i8* bitcast (i8** getelementptr inbounds ([5 x i8*]* @_ZTVN5Test21CE, i64 0, i64 4) to i8*)] ; <[2 x i8*]*> [#uses=0]