Fixup object layout when we have a primary base (it goes first). Start preping for

virtual base layout.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78265 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 10295f18835c37925c8f7a9153a18ede5852cfb8..3131fdb852cc891d9ca00f25a17ff83038a67f9c 100644 (file)
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -25,10 +25,14 @@ ASTRecordLayoutBuilder::ASTRecordLayoutBuilder(ASTContext &Ctx)
   : Ctx(Ctx), Size(0), Alignment(8), StructPacking(0), NextOffset(0),
   IsUnion(false), NonVirtualSize(0), NonVirtualAlignment(8) {}
 
+/// LayoutVtable - Lay out the vtable and set PrimaryBase.
 void ASTRecordLayoutBuilder::LayoutVtable(const CXXRecordDecl *RD) {
   // FIXME: audit indirect virtual bases
-  if (!RD->isPolymorphic() && !RD->getNumVBases())
+  if (!RD->isPolymorphic() && !RD->getNumVBases()) {
+    // There is no primary base in this case.
+    setPrimaryBase(0);
     return;
+  }
 
   SelectPrimaryBase(RD);
   if (PrimaryBase == 0) {
@@ -46,7 +50,9 @@ ASTRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) {
     if (!i->isVirtual()) {
       const CXXRecordDecl *Base = 
         cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
-      LayoutNonVirtualBase(Base);
+      // Skip the PrimaryBase here, as it is laid down first.
+      if (Base != PrimaryBase)
+        LayoutNonVirtualBase(Base);
     }
   }
 }
@@ -186,12 +192,10 @@ void ASTRecordLayoutBuilder::Layout(const RecordDecl *D) {
   // If this is a C++ class, lay out the nonvirtual bases.
   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
     LayoutVtable(RD);
+    // PrimaryBase goes first.
+    if (PrimaryBase)
+      LayoutNonVirtualBase(PrimaryBase);
     LayoutNonVirtualBases(RD);
-
-    // FIXME: audit indirect virtual bases
-    assert (RD->getNumVBases() == 0
-            && "FIXME: We don't support virtual bases yet!");
-    // FIXME: We need to layout the virtual bases in the complete object layout.
   }
 
   LayoutFields(D);

diff --git a/test/CodeGenCXX/virt.cpp b/test/CodeGenCXX/virt.cpp
index 55c9b5d923b246d133ddc555e2a41fbd100871ce..0d43b80ea7c5633933a41db913385c1e8b8313e0 100644 (file)
--- a/test/CodeGenCXX/virt.cpp
+++ b/test/CodeGenCXX/virt.cpp
@@ -7,6 +7,7 @@
 struct B {
   virtual void bar1();
   virtual void bar2();
+  int b;
 };
 void B::bar1() { }
 void B::bar2() { }
@@ -18,22 +19,42 @@ struct C {
 void C::bee1() { }
 void C::bee2() { }
 
-static_assert (sizeof (B) == (sizeof(void *)), "vtable pointer layout");
+struct D {
+  virtual void boo();
+};
+void D::boo() { }
+
+struct E {
+  int e;
+};
 
-class A : public B, public C {
+static_assert (sizeof (C) == (sizeof(void *)), "vtable pointer layout");
+
+class A : public E, public B, public C, /* virtual */ public D {
 public:
   virtual void foo1();
   virtual void foo2();
   A() { }
-} *a;
+  int a;
+} *ap;
 void A::foo1() { }
 void A::foo2() { }
 
 int main() {
   A a;
   B b;
+  ap->e = 1;
+  ap->b = 2;
 }
 
+// CHECK-LP32: main:
+// CHECK-LP32: movl $1, 8(%eax)
+// CHECK-LP32: movl $2, 4(%eax)
+
+// CHECK-LP64: main:
+// CHECK-LP64: movl $1, 12(%rax)
+// CHECK-LP64: movl $2, 8(%rax)
+
 // CHECK-LP64: __ZTV1B:
 // CHECK-LP64: .space 8
 // CHECK-LP64: .space 8
@@ -53,7 +74,7 @@ int main() {
 // CHECK-LP64: .quad __ZN1B4bar2Ev
 // CHECK-LP64: .quad __ZN1A4foo1Ev
 // CHECK-LP64: .quad __ZN1A4foo2Ev
-// CHECK-LP64: .quad 18446744073709551608
+// CHECK-LP64: .quad 18446744073709551600
 // CHECK-LP64: .space 8
 // CHECK-LP64: .quad __ZN1C4bee1Ev
 // CHECK-LP64: .quad __ZN1C4bee2Ev
@@ -65,7 +86,7 @@ int main() {
 // CHECK-LP32: .long __ZN1B4bar2Ev
 // CHECK-LP32: .long __ZN1A4foo1Ev
 // CHECK-LP32: .long __ZN1A4foo2Ev
-// CHECK-LP32: .long 4294967292
+// CHECK-LP32: .long 4294967284
 // CHECK-LP32: .space 4
 // CHECK-LP32: .long __ZN1C4bee1Ev
 // CHECK-LP32: .long __ZN1C4bee2Ev