From 5c60a6f5970e581fdcb0638d80e1fd0998bcca6c Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Thu, 18 Feb 2010 19:59:28 +0000
Subject: Make deleting and complete dtor variants defer to other dtor variants
 by calling them as subroutines.  This triggers whenever the alias
 optimization doesn't, i.e. when the dtor has linkonce linkage or there are
 virtual bases or it's the deleting dtor.

llvm-svn: 96605
---
 clang/lib/CodeGen/CGClass.cpp | 87 +++++++++++++++++++++++++------------------
 1 file changed, 51 insertions(+), 36 deletions(-)

(limited to 'clang/lib/CodeGen/CGClass.cpp')

diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 863b09c86a9..7b8e736900e 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -477,12 +477,21 @@ static llvm::Value *GetVTTParameter(CodeGenFunction &CGF, GlobalDecl GD) {
   
   const CXXRecordDecl *RD = cast<CXXMethodDecl>(CGF.CurFuncDecl)->getParent();
   const CXXRecordDecl *Base = cast<CXXMethodDecl>(GD.getDecl())->getParent();
-  
+
   llvm::Value *VTT;
 
-  uint64_t SubVTTIndex = 
-    CGF.CGM.getVtableInfo().getSubVTTIndex(RD, Base);
-  assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!");
+  uint64_t SubVTTIndex;
+
+  // If the record matches the base, this is the complete ctor/dtor
+  // variant calling the base variant in a class with virtual bases.
+  if (RD == Base) {
+    assert(!CGVtableInfo::needsVTTParameter(CGF.CurGD) &&
+           "doing no-op VTT offset in base dtor/ctor?");
+    SubVTTIndex = 0;
+  } else {
+    SubVTTIndex = CGF.CGM.getVtableInfo().getSubVTTIndex(RD, Base);
+    assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!");
+  }
   
   if (CGVtableInfo::needsVTTParameter(CGF.CurGD)) {
     // A VTT parameter was passed to the constructor, use it.
@@ -962,7 +971,6 @@ void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD,
 /// EmitDtorEpilogue - Emit all code that comes at the end of class's
 /// destructor. This is to call destructors on members and base classes
 /// in reverse order of their construction.
-/// FIXME: This needs to take a CXXDtorType.
 void CodeGenFunction::EmitDtorEpilogue(const CXXDestructorDecl *DD,
                                        CXXDtorType DtorType) {
   assert(!DD->isTrivial() &&
@@ -970,6 +978,44 @@ void CodeGenFunction::EmitDtorEpilogue(const CXXDestructorDecl *DD,
 
   const CXXRecordDecl *ClassDecl = DD->getParent();
 
+  // In a deleting destructor, we've already called the complete
+  // destructor as a subroutine, so we just have to delete the
+  // appropriate value.
+  if (DtorType == Dtor_Deleting) {
+    assert(DD->getOperatorDelete() && 
+           "operator delete missing - EmitDtorEpilogue");
+    EmitDeleteCall(DD->getOperatorDelete(), LoadCXXThis(),
+                   getContext().getTagDeclType(ClassDecl));
+    return;
+  }
+
+  // For complete destructors, we've already called the base
+  // destructor (in GenerateBody), so we just need to destruct all the
+  // virtual bases.
+  if (DtorType == Dtor_Complete) {
+    // Handle virtual bases.
+    for (CXXRecordDecl::reverse_base_class_const_iterator I = 
+           ClassDecl->vbases_rbegin(), E = ClassDecl->vbases_rend();
+              I != E; ++I) {
+      const CXXBaseSpecifier &Base = *I;
+      CXXRecordDecl *BaseClassDecl
+        = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl());
+    
+      // Ignore trivial destructors.
+      if (BaseClassDecl->hasTrivialDestructor())
+        continue;
+      const CXXDestructorDecl *D = BaseClassDecl->getDestructor(getContext());
+      llvm::Value *V = GetAddressOfBaseOfCompleteClass(LoadCXXThis(),
+                                                       true,
+                                                       ClassDecl,
+                                                       BaseClassDecl);
+      EmitCXXDestructorCall(D, Dtor_Base, V);
+    }
+    return;
+  }
+
+  assert(DtorType == Dtor_Base);
+
   // Collect the fields.
   llvm::SmallVector<const FieldDecl *, 16> FieldDecls;
   for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
@@ -1042,37 +1088,6 @@ void CodeGenFunction::EmitDtorEpilogue(const CXXDestructorDecl *DD,
                                            /*NullCheckValue=*/false);
     EmitCXXDestructorCall(D, Dtor_Base, V);
   }
-
-  // If we're emitting a base destructor, we don't want to emit calls to the
-  // virtual bases.
-  if (DtorType == Dtor_Base)
-    return;
-  
-  // Handle virtual bases.
-  for (CXXRecordDecl::reverse_base_class_const_iterator I = 
-       ClassDecl->vbases_rbegin(), E = ClassDecl->vbases_rend(); I != E; ++I) {
-    const CXXBaseSpecifier &Base = *I;
-    CXXRecordDecl *BaseClassDecl
-      = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl());
-    
-    // Ignore trivial destructors.
-    if (BaseClassDecl->hasTrivialDestructor())
-      continue;
-    const CXXDestructorDecl *D = BaseClassDecl->getDestructor(getContext());
-    llvm::Value *V = GetAddressOfBaseOfCompleteClass(LoadCXXThis(),
-                                                     true,
-                                                     ClassDecl,
-                                                     BaseClassDecl);
-    EmitCXXDestructorCall(D, Dtor_Base, V);
-  }
-    
-  // If we have a deleting destructor, emit a call to the delete operator.
-  if (DtorType == Dtor_Deleting) {
-    assert(DD->getOperatorDelete() && 
-           "operator delete missing - EmitDtorEpilogue");
-    EmitDeleteCall(DD->getOperatorDelete(), LoadCXXThis(),
-                   getContext().getTagDeclType(ClassDecl));
-  }
 }
 
 /// EmitCXXAggrConstructorCall - This routine essentially creates a (nested)
-- 
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