From eb19fa948173502f47c26357c2ec41aa4be197b4 Mon Sep 17 00:00:00 2001
From: Mike Stump <mrs@apple.com>
Date: Thu, 6 Aug 2009 13:41:24 +0000
Subject: [PATCH] Layout virtual bases.  Work in progress.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78308 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/AST/RecordLayoutBuilder.cpp | 27 +++++++++++++++++++++++----
 lib/AST/RecordLayoutBuilder.h   |  4 +++-
 lib/CodeGen/CGCXX.cpp           |  4 +---
 test/CodeGenCXX/virt.cpp        | 22 +++++++++++++++++++++-
 4 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 833e053e14..5f23a8ca46 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -52,7 +52,7 @@ ASTRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) {
         cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
       // Skip the PrimaryBase here, as it is laid down first.
       if (Base != PrimaryBase)
-        LayoutNonVirtualBase(Base);
+        LayoutBaseNonVirtually(Base);
     }
   }
 }
@@ -155,7 +155,22 @@ void ASTRecordLayoutBuilder::SelectPrimaryBase(const CXXRecordDecl *RD) {
   return;
 }
 
-void ASTRecordLayoutBuilder::LayoutNonVirtualBase(const CXXRecordDecl *RD) {
+void ASTRecordLayoutBuilder::LayoutVirtualBase(const CXXRecordDecl *RD) {
+  LayoutBaseNonVirtually(RD);
+}
+
+void ASTRecordLayoutBuilder::LayoutVirtualBases(const CXXRecordDecl *RD) {
+  // FIXME: audit indirect virtual bases
+  for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(),
+         e = RD->vbases_end(); i != e; ++i) {
+    const CXXRecordDecl *Base = 
+      cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+    if (Base != PrimaryBase)
+      LayoutVirtualBase(Base);
+  }
+}
+
+void ASTRecordLayoutBuilder::LayoutBaseNonVirtually(const CXXRecordDecl *RD) {
   const ASTRecordLayout &BaseInfo = Ctx.getASTRecordLayout(RD);
     assert(BaseInfo.getDataSize() > 0 && 
            "FIXME: Handle empty classes.");
@@ -190,11 +205,12 @@ void ASTRecordLayoutBuilder::Layout(const RecordDecl *D) {
     UpdateAlignment(AA->getAlignment());
 
   // If this is a C++ class, lay out the nonvirtual bases.
-  if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
+  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D);
+  if (RD) {
     LayoutVtable(RD);
     // PrimaryBase goes first.
     if (PrimaryBase)
-      LayoutNonVirtualBase(PrimaryBase);
+      LayoutBaseNonVirtually(PrimaryBase);
     LayoutNonVirtualBases(RD);
   }
 
@@ -203,6 +219,9 @@ void ASTRecordLayoutBuilder::Layout(const RecordDecl *D) {
   NonVirtualSize = Size;
   NonVirtualAlignment = Alignment;
 
+  if (RD)
+    LayoutVirtualBases(RD);
+
   // Finally, round the size of the total struct up to the alignment of the
   // struct itself.
   FinishLayout();
diff --git a/lib/AST/RecordLayoutBuilder.h b/lib/AST/RecordLayoutBuilder.h
index a6c9c5e873..a745c85db4 100644
--- a/lib/AST/RecordLayoutBuilder.h
+++ b/lib/AST/RecordLayoutBuilder.h
@@ -58,7 +58,9 @@ class ASTRecordLayoutBuilder {
   bool IsNearlyEmpty(const CXXRecordDecl *RD);
   void LayoutVtable(const CXXRecordDecl *RD);
   void LayoutNonVirtualBases(const CXXRecordDecl *RD);
-  void LayoutNonVirtualBase(const CXXRecordDecl *RD);
+  void LayoutBaseNonVirtually(const CXXRecordDecl *RD);
+  void LayoutVirtualBase(const CXXRecordDecl *RD);
+  void LayoutVirtualBases(const CXXRecordDecl *RD);
   
   /// FinishLayout - Finalize record layout. Adjust record size based on the
   /// alignment.
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 0f76266acc..eb8e87d372 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -623,10 +623,8 @@ llvm::Value *CodeGenFunction::GenerateVtable(const CXXRecordDecl *RD) {
 /// base classes and non-static data members belonging to this constructor.
 void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD) {
   const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(CD->getDeclContext());
-  assert(ClassDecl->getNumVBases() == 0
-         && "FIXME: virtual base initialization unsupported");
+  // FIXME: Add vbase initialization
   llvm::Value *LoadOfThis = 0;
-
   
   for (CXXConstructorDecl::init_const_iterator B = CD->init_begin(),
        E = CD->init_end();
diff --git a/test/CodeGenCXX/virt.cpp b/test/CodeGenCXX/virt.cpp
index 0d43b80ea7..a90e7228d3 100644
--- a/test/CodeGenCXX/virt.cpp
+++ b/test/CodeGenCXX/virt.cpp
@@ -30,7 +30,7 @@ struct E {
 
 static_assert (sizeof (C) == (sizeof(void *)), "vtable pointer layout");
 
-class A : public E, public B, public C, /* virtual */ public D {
+class A : public E, public B, public C {
 public:
   virtual void foo1();
   virtual void foo2();
@@ -90,3 +90,23 @@ int main() {
 // CHECK-LP32: .space 4
 // CHECK-LP32: .long __ZN1C4bee1Ev
 // CHECK-LP32: .long __ZN1C4bee2Ev
+
+struct D1 {
+  virtual void bar();
+  void *d1;
+};
+void D1::bar() { }
+
+class F : virtual public D1, virtual public D {
+public:
+  virtual void foo();
+  void *f;
+};
+void F::foo() { }
+
+void test2() {
+  F f;
+  f.f = 0;
+}
+  
+static_assert(sizeof(F) == sizeof(void*)*4, "invalid vbase size");
-- 
2.40.0