[cfe-commits] r77556 - in /cfe/trunk: lib/AST/RecordLayoutBuilder.cpp lib/AST/RecordLayoutBuilder.h lib/CodeGen/CodeGenTypes.cpp test/CodeGenCXX/virt.cpp

[Mike Stump]

Author: mrs
Date: Wed Jul 29 19:22:38 2009
New Revision: 77556

URL: http://llvm.org/viewvc/llvm-project?rev=77556&view=rev
Log:
Add ability to layout the vtable pointer in trivial cases.  I noticed
that we would silently do bad things with virtual bases in the layout
code, so, we just turn them off.  When people do better things with
them, we can turn them back on.

Added:
    cfe/trunk/test/CodeGenCXX/virt.cpp
Modified:
    cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
    cfe/trunk/lib/AST/RecordLayoutBuilder.h
    cfe/trunk/lib/CodeGen/CodeGenTypes.cpp

Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/RecordLayoutBuilder.cpp?rev=77556&r1=77555&r2=77556&view=diff

==============================================================================
--- cfe/trunk/lib/AST/RecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/AST/RecordLayoutBuilder.cpp Wed Jul 29 19:22:38 2009
@@ -24,11 +24,19 @@
   : Ctx(Ctx), Size(0), Alignment(8), StructPacking(0), NextOffset(0),
   IsUnion(false), NonVirtualSize(0), NonVirtualAlignment(8) {}
 
+void ASTRecordLayoutBuilder::LayoutVtable(const CXXRecordDecl *RD) {
+  if (RD->isPolymorphic())
+    {
+      assert (RD->getNumBases() == 0 && "no polymorphic inheritance yet");
+      int AS = 0;
+      UpdateAlignment(Ctx.Target.getPointerAlign(AS));
+      Size += Ctx.Target.getPointerWidth(AS);
+      NextOffset = Size;
+    }
+}
+
 void 
 ASTRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) {
-  assert(!RD->isPolymorphic() && 
-         "FIXME: We don't support polymorphic classes yet!");
-  
   for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
        e = RD->bases_end(); i != e; ++i) {
     if (!i->isVirtual()) {
@@ -74,14 +82,20 @@
     UpdateAlignment(AA->getAlignment());
 
   // If this is a C++ class, lay out the nonvirtual bases.
-  if (Ctx.getLangOptions().CPlusPlus)
-    LayoutNonVirtualBases(cast<CXXRecordDecl>(D));
+  if (Ctx.getLangOptions().CPlusPlus) {
+    const CXXRecordDecl *RD = cast<CXXRecordDecl>(D);
+    LayoutVtable(RD);
+    LayoutNonVirtualBases(RD);
+
+    assert (RD->getNumVBases() == 0
+            && "FIXME: We don't support virtual bases yet!");
+  }
 
   LayoutFields(D);
   
   NonVirtualSize = Size;
   NonVirtualAlignment = Alignment;
-  
+
   // Finally, round the size of the total struct up to the alignment of the
   // struct itself.
   FinishLayout();

Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/RecordLayoutBuilder.h?rev=77556&r1=77555&r2=77556&view=diff

==============================================================================
--- cfe/trunk/lib/AST/RecordLayoutBuilder.h (original)
+++ cfe/trunk/lib/AST/RecordLayoutBuilder.h Wed Jul 29 19:22:38 2009
@@ -48,6 +48,7 @@
   void LayoutFields(const RecordDecl *D);
   void LayoutField(const FieldDecl *D);
 
+  void LayoutVtable(const CXXRecordDecl *RD);
   void LayoutNonVirtualBases(const CXXRecordDecl *RD);
   void LayoutNonVirtualBase(const CXXRecordDecl *RD);
   

Modified: cfe/trunk/lib/CodeGen/CodeGenTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenTypes.cpp?rev=77556&r1=77555&r2=77556&view=diff

==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenTypes.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenTypes.cpp Wed Jul 29 19:22:38 2009
@@ -381,8 +381,6 @@
 
   // FIXME. This may have to move to a better place.
   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
-    assert(!RD->isPolymorphic() &&
-           "FIXME: We don't support polymorphic classes yet!");
     for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
          e = RD->bases_end(); i != e; ++i) {
       if (!i->isVirtual()) {

Added: cfe/trunk/test/CodeGenCXX/virt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/virt.cpp?rev=77556&view=auto

==============================================================================
--- cfe/trunk/test/CodeGenCXX/virt.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/virt.cpp Wed Jul 29 19:22:38 2009
@@ -0,0 +1,8 @@
+// RUN: clang-cc %s -emit-llvm -o - -std=c++0x
+
+class A {
+public:
+  virtual void foo();
+};
+
+static_assert (sizeof (A) == (sizeof(void *)), "vtable pointer layout");