More VTT builder fixes. With these fixes we now correctly handle the very complex...

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93725 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
index 2f5681e181a12f8e15e6397600c56726f1fd05da..b2fb8662fe632b6b2444e30c7504e93697405509 100644 (file)
--- a/lib/CodeGen/CGVtable.cpp
+++ b/lib/CodeGen/CGVtable.cpp
@@ -1221,6 +1221,10 @@ class VTTBuilder {
   llvm::Constant *ClassVtbl;
   llvm::LLVMContext &VMContext;
 
+  /// SeenVBasesInSecondary - The seen virtual bases when building the 
+  /// secondary virtual pointers.
+  llvm::SmallPtrSet<const CXXRecordDecl *, 32> SeenVBasesInSecondary;
+
   llvm::DenseMap<const CXXRecordDecl *, uint64_t> SubVTTIndicies;
   
   bool GenerateDefinition;
@@ -1314,6 +1318,10 @@ class VTTBuilder {
            e = RD->bases_end(); i != e; ++i) {
       const CXXRecordDecl *Base =
         cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+
+      // We only want to visit each virtual base once.
+      if (i->isVirtual() && SeenVBasesInSecondary.count(Base))
+        continue;
       
       // Itanium C++ ABI 2.6.2:
       //   Secondary virtual pointers are present for all bases with either
@@ -1352,8 +1360,13 @@ class VTTBuilder {
           
           init = BuildVtablePtr(init, Class, Base, BaseOffset);
         }
+
         Inits.push_back(init);
       }
+      
+      if (i->isVirtual())
+        SeenVBasesInSecondary.insert(Base);
+      
       Secondary(Base, subvtbl, subVtblClass, BaseOffset, BaseMorallyVirtual);
     }
   }
@@ -1388,6 +1401,9 @@ class VTTBuilder {
     // then the secondary VTTs....
     SecondaryVTTs(RD, Offset, MorallyVirtual);
 
+    // Make sure to clear the set of seen virtual bases.
+    SeenVBasesInSecondary.clear();
+
     // and last the secondary vtable pointers.
     Secondary(RD, Vtable, VtableClass, Offset, MorallyVirtual);
   }
@@ -1420,7 +1436,7 @@ class VTTBuilder {
       if (i->isVirtual() && !SeenVBase.count(Base)) {
         SeenVBase.insert(Base);
         uint64_t BaseOffset = BLayout.getVBaseClassOffset(Base);
-        BuildVTT(Base, BaseOffset, true);
+        BuildVTT(Base, BaseOffset, false);
       }
       VirtualVTTs(Base);
     }
@@ -1444,6 +1460,9 @@ public:
     // then the secondary VTTs...
     SecondaryVTTs(Class);
 
+    // Make sure to clear the set of seen virtual bases.
+    SeenVBasesInSecondary.clear();
+
     // then the secondary vtable pointers...
     Secondary(Class, ClassVtbl, Class);
 

diff --git a/test/CodeGenCXX/vtt-layout.cpp b/test/CodeGenCXX/vtt-layout.cpp
index 1e78c9048db20a9f6bda08b6005075821b633f35..d7d4227ed01d9bdb516c86d3c05e38f98abd3219 100644 (file)
--- a/test/CodeGenCXX/vtt-layout.cpp
+++ b/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 @@ struct B : virtual A {
 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 @@ namespace Test2 {
   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]