During codegen of a virtual call we would extract any casts in the expression

to see if we had an underlying final class or method, but we would then
use the cast type to do the call, resulting in a direct call to the wrong
method.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159212 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 33 deletions

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index f1d0395714..f35287d540 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -56,30 +56,6 @@ RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD,
                   Callee, ReturnValue, Args, MD);
 }
 
-static const CXXRecordDecl *getMostDerivedClassDecl(const Expr *Base) {
-  const Expr *E = Base;
-  
-  while (true) {
-    E = E->IgnoreParens();
-    if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
-      if (CE->getCastKind() == CK_DerivedToBase || 
-          CE->getCastKind() == CK_UncheckedDerivedToBase ||
-          CE->getCastKind() == CK_NoOp) {
-        E = CE->getSubExpr();
-        continue;
-      }
-    }
-
-    break;
-  }
-
-  QualType DerivedType = E->getType();
-  if (const PointerType *PTy = DerivedType->getAs<PointerType>())
-    DerivedType = PTy->getPointeeType();
-
-  return cast<CXXRecordDecl>(DerivedType->castAs<RecordType>()->getDecl());
-}
-
 // FIXME: Ideally Expr::IgnoreParenNoopCasts should do this, but it doesn't do
 // quite what we want.
 static const Expr *skipNoOpCastsAndParens(const Expr *E) {
@@ -126,7 +102,8 @@ static bool canDevirtualizeMemberFunctionCalls(ASTContext &Context,
   //   b->f();
   // }
   //
-  const CXXRecordDecl *MostDerivedClassDecl = getMostDerivedClassDecl(Base);
+  const CXXRecordDecl *MostDerivedClassDecl =
+    Base->getMostDerivedClassDeclForType();
   if (MostDerivedClassDecl->hasAttr<FinalAttr>())
     return true;
 
@@ -247,10 +224,13 @@ RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
   //
   // We also don't emit a virtual call if the base expression has a record type
   // because then we know what the type is.
-  bool UseVirtualCall;
-  UseVirtualCall = MD->isVirtual() && !ME->hasQualifier()
-                   && !canDevirtualizeMemberFunctionCalls(getContext(),
-                                                          ME->getBase(), MD);
+  const Expr *Base = ME->getBase();
+  bool UseVirtualCall = MD->isVirtual() && !ME->hasQualifier()
+                        && !canDevirtualizeMemberFunctionCalls(getContext(),
+                                                               Base, MD);
+  const CXXRecordDecl *MostDerivedClassDecl =
+    Base->getMostDerivedClassDeclForType();
+
   llvm::Value *Callee;
   if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
     if (UseVirtualCall) {
@@ -260,8 +240,13 @@ RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
           MD->isVirtual() &&
           ME->hasQualifier())
         Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty);
-      else
-        Callee = CGM.GetAddrOfFunction(GlobalDecl(Dtor, Dtor_Complete), Ty);
+      else {
+        const CXXMethodDecl *DM =
+          Dtor->getCorrespondingMethodInClass(MostDerivedClassDecl);
+        assert(DM);
+        const CXXDestructorDecl *DDtor = cast<CXXDestructorDecl>(DM);
+        Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty);
+      }
     }
   } else if (const CXXConstructorDecl *Ctor =
                dyn_cast<CXXConstructorDecl>(MD)) {
@@ -273,8 +258,12 @@ RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
         MD->isVirtual() &&
         ME->hasQualifier())
       Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty);
-    else 
-      Callee = CGM.GetAddrOfFunction(MD, Ty);
+    else {
+      const CXXMethodDecl *DerivedMethod =
+        MD->getCorrespondingMethodInClass(MostDerivedClassDecl);
+      assert(DerivedMethod);
+      Callee = CGM.GetAddrOfFunction(DerivedMethod, Ty);
+    }
   }
 
   return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0,