Implement John McCall's review of r159212 other than the this pointer not
being updated. Will fix that in a second.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 77684ee..7a9cfae 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -665,12 +665,14 @@
static bool hasAnyTypeDependentArguments(llvm::ArrayRef<Expr *> Exprs);
- /// \brief If we have class type (or pointer to class type), return the
- /// class decl. Return NULL otherwise.
+ /// \brief For an expression of class type or pointer to class type,
+ /// return the most derived class decl the expression is known to refer to.
///
/// If this expression is a cast, this method looks through it to find the
- /// most derived decl that can be infered from the expression.
- const CXXRecordDecl *getMostDerivedClassDeclForType() const;
+ /// most derived decl that can be inferred from the expression.
+ /// This is valid because derived-to-base conversions have undefined
+ /// behavior if the object isn't dynamically of the derived type.
+ const CXXRecordDecl *getBestDynamicClassType() const;
static bool classof(const Stmt *T) {
return T->getStmtClass() >= firstExprConstant &&
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 22d15be..15cf660 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -33,7 +33,7 @@
#include <cstring>
using namespace clang;
-const CXXRecordDecl *Expr::getMostDerivedClassDeclForType() const {
+const CXXRecordDecl *Expr::getBestDynamicClassType() const {
const Expr *E = this;
while (true) {
@@ -51,15 +51,10 @@
}
QualType DerivedType = E->getType();
- if (DerivedType->isDependentType())
- return NULL;
if (const PointerType *PTy = DerivedType->getAs<PointerType>())
DerivedType = PTy->getPointeeType();
const RecordType *Ty = DerivedType->castAs<RecordType>();
- if (!Ty)
- return NULL;
-
Decl *D = Ty->getDecl();
return cast<CXXRecordDecl>(D);
}
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 372eb54..30324b9 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -102,8 +102,7 @@
// b->f();
// }
//
- const CXXRecordDecl *MostDerivedClassDecl =
- Base->getMostDerivedClassDeclForType();
+ const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType();
if (MostDerivedClassDecl->hasAttr<FinalAttr>())
return true;
@@ -228,8 +227,7 @@
bool UseVirtualCall = MD->isVirtual() && !ME->hasQualifier()
&& !canDevirtualizeMemberFunctionCalls(getContext(),
Base, MD);
- const CXXRecordDecl *MostDerivedClassDecl =
- Base->getMostDerivedClassDeclForType();
+ const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType();
llvm::Value *Callee;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index bc77e6f..2a7a8b9 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -10854,8 +10854,9 @@
if (!MD)
return;
const Expr *Base = ME->getBase();
- const CXXRecordDecl *MostDerivedClassDecl
- = Base->getMostDerivedClassDeclForType();
+ if (Base->getType()->isDependentType())
+ return;
+ const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType();
if (!MostDerivedClassDecl)
return;
CXXMethodDecl *DM = MD->getCorrespondingMethodInClass(MostDerivedClassDecl);
