Index: lib/Sema/SemaNamedCast.cpp
===================================================================
--- lib/Sema/SemaNamedCast.cpp	(revision 0)
+++ lib/Sema/SemaNamedCast.cpp	(revision 0)
@@ -0,0 +1,707 @@
+//===--- SemaNamedCast.cpp - Semantic Analysis for named casts ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements semantic analysis for C++ named casts.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sema.h"
+#include "SemaInherit.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/SmallVector.h"
+using namespace clang;
+
+// Helpers for ActOnCXXCasts
+static void CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                           const SourceRange &OpRange,
+                           const SourceRange &DestRange);
+static void CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                                 const SourceRange &OpRange,
+                                 const SourceRange &DestRange);
+static void CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                            const SourceRange &OpRange);
+static void CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                             const SourceRange &OpRange,
+                             const SourceRange &DestRange);
+static bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType);
+static bool IsStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
+                                      QualType DestType);
+static bool IsStaticPointerDowncast(Sema &Self, QualType SrcType,
+                                    QualType DestType);
+static bool IsStaticDowncast(Sema &Self, QualType SrcType, QualType DestType);
+static ImplicitConversionSequence TryDirectInitialization(Sema &sema,
+                                                          Expr *SrcExpr,
+                                                          QualType DestType);
+
+/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
+Action::ExprResult
+Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
+                        SourceLocation LAngleBracketLoc, TypeTy *Ty,
+                        SourceLocation RAngleBracketLoc,
+                        SourceLocation LParenLoc, ExprTy *E,
+                        SourceLocation RParenLoc) {
+  Expr *Ex = (Expr*)E;
+  QualType DestType = QualType::getFromOpaquePtr(Ty);
+  SourceRange OpRange(OpLoc, RParenLoc);
+  SourceRange DestRange(LAngleBracketLoc, RAngleBracketLoc);
+
+  switch (Kind) {
+  default: assert(0 && "Unknown C++ cast!");
+
+  case tok::kw_const_cast:
+    CheckConstCast(*this, Ex, DestType, OpRange, DestRange);
+    return new CXXConstCastExpr(DestType.getNonReferenceType(), Ex, 
+                                DestType, OpLoc);
+
+  case tok::kw_dynamic_cast:
+    CheckDynamicCast(*this, Ex, DestType, OpRange, DestRange);
+    return new CXXDynamicCastExpr(DestType.getNonReferenceType(), Ex, 
+                                  DestType, OpLoc);
+
+  case tok::kw_reinterpret_cast:
+    CheckReinterpretCast(*this, Ex, DestType, OpRange, DestRange);
+    return new CXXReinterpretCastExpr(DestType.getNonReferenceType(), Ex, 
+                                      DestType, OpLoc);
+
+  case tok::kw_static_cast:
+    CheckStaticCast(*this, Ex, DestType, OpRange);
+    return new CXXStaticCastExpr(DestType.getNonReferenceType(), Ex, 
+                                 DestType, OpLoc);
+  }
+
+  return true;
+}
+
+/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
+/// like this:
+/// const char *str = "literal";
+/// legacy_function(const_cast\<char*\>(str));
+void
+CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+               const SourceRange &OpRange, const SourceRange &DestRange)
+{
+  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+
+  DestType = Self.Context.getCanonicalType(DestType);
+  QualType SrcType = SrcExpr->getType();
+  if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
+    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
+      // Cannot cast non-lvalue to reference type.
+      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue,
+        "const_cast", OrigDestType.getAsString(), SrcExpr->getSourceRange());
+      return;
+    }
+
+    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
+    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
+    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
+    SrcType = Self.Context.getPointerType(SrcType);
+  } else {
+    // C++ 5.2.11p1: Otherwise, the result is an rvalue and the
+    //   lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
+    //   conversions are performed on the expression.
+    Self.DefaultFunctionArrayConversion(SrcExpr);
+    SrcType = SrcExpr->getType();
+  }
+
+  if (!DestType->isPointerType()) {
+    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
+    // was a reference type, we converted it to a pointer above.
+    // C++ 5.2.11p3: For two pointer types [...]
+    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest,
+      OrigDestType.getAsString(), DestRange);
+    return;
+  }
+  if (DestType->isFunctionPointerType()) {
+    // Cannot cast direct function pointers.
+    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
+    // T is the ultimate pointee of source and target type.
+    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest,
+      OrigDestType.getAsString(), DestRange);
+    return;
+  }
+  SrcType = Self.Context.getCanonicalType(SrcType);
+
+  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
+  // completely equal.
+  // FIXME: const_cast should probably not be able to convert between pointers
+  // to different address spaces.
+  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
+  // in multi-level pointers may change, but the level count must be the same,
+  // as must be the final pointee type.
+  while (SrcType != DestType &&
+         Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
+    SrcType = SrcType.getUnqualifiedType();
+    DestType = DestType.getUnqualifiedType();
+  }
+
+  // Doug Gregor said to disallow this until users complain.
+#if 0
+  // If we end up with constant arrays of equal size, unwrap those too. A cast
+  // from const int [N] to int (&)[N] is invalid by my reading of the
+  // standard, but g++ accepts it even with -ansi -pedantic.
+  // No more than one level, though, so don't embed this in the unwrap loop
+  // above.
+  const ConstantArrayType *SrcTypeArr, *DestTypeArr;
+  if ((SrcTypeArr = Self.Context.getAsConstantArrayType(SrcType)) &&
+     (DestTypeArr = Self.Context.getAsConstantArrayType(DestType)))
+  {
+    if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
+      // Different array sizes.
+      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic,
+        "const_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
+        OpRange);
+      return;
+    }
+    SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
+    DestType = DestTypeArr->getElementType().getUnqualifiedType();
+  }
+#endif
+
+  // Since we're dealing in canonical types, the remainder must be the same.
+  if (SrcType != DestType) {
+    // Cast between unrelated types.
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "const_cast",
+      OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
+    return;
+  }
+}
+
+/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
+/// valid.
+/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
+/// like this:
+/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
+void
+CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                     const SourceRange &OpRange, const SourceRange &DestRange)
+{
+  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+
+  DestType = Self.Context.getCanonicalType(DestType);
+  QualType SrcType = SrcExpr->getType();
+  if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
+    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
+      // Cannot cast non-lvalue to reference type.
+      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue,
+        "reinterpret_cast", OrigDestType.getAsString(),
+        SrcExpr->getSourceRange());
+      return;
+    }
+
+    // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
+    //   same effect as the conversion *reinterpret_cast<T*>(&x) with the
+    //   built-in & and * operators.
+    // This code does this transformation for the checked types.
+    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
+    SrcType = Self.Context.getPointerType(SrcType);
+  } else {
+    // C++ 5.2.10p1: [...] the lvalue-to-rvalue, array-to-pointer, and
+    //   function-to-pointer standard conversions are performed on the
+    //   expression v.
+    Self.DefaultFunctionArrayConversion(SrcExpr);
+    SrcType = SrcExpr->getType();
+  }
+
+  // Canonicalize source for comparison.
+  SrcType = Self.Context.getCanonicalType(SrcType);
+
+  bool destIsPtr = DestType->isPointerType();
+  bool srcIsPtr = SrcType->isPointerType();
+  if (!destIsPtr && !srcIsPtr) {
+    // Except for std::nullptr_t->integer, which is not supported yet, and
+    // lvalue->reference, which is handled above, at least one of the two
+    // arguments must be a pointer.
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic,
+      "reinterpret_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
+      OpRange);
+    return;
+  }
+
+  if (SrcType == DestType) {
+    // C++ 5.2.10p2 has a note that mentions that, subject to all other
+    // restrictions, a cast to the same type is allowed. The intent is not
+    // entirely clear here, since all other paragraphs explicitly forbid casts
+    // to the same type. However, the behavior of compilers is pretty consistent
+    // on this point: allow same-type conversion if the involved are pointers,
+    // disallow otherwise.
+    return;
+  }
+
+  // Note: Clang treats enumeration types as integral types. If this is ever
+  // changed for C++, the additional check here will be redundant.
+  if (DestType->isIntegralType() && !DestType->isEnumeralType()) {
+    assert(srcIsPtr && "One operand must be a pointer here");
+    // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
+    //   type large enough to hold it.
+    if (Self.Context.getTypeSize(SrcType) >
+        Self.Context.getTypeSize(DestType)) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int,
+        OrigDestType.getAsString(), DestRange);
+    }
+    return;
+  }
+
+  if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
+    assert(destIsPtr && "One operand must be a pointer here");
+    // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
+    //   converted to a pointer.
+    return;
+  }
+
+  if (!destIsPtr || !srcIsPtr) {
+    // With the valid non-pointer conversions out of the way, we can be even
+    // more stringent.
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic,
+      "reinterpret_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
+      OpRange);
+    return;
+  }
+
+  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
+  if (CastsAwayConstness(Self, SrcType, DestType)) {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away,
+      "reinterpret_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
+      OpRange);
+    return;
+  }
+
+  // Not casting away constness, so the only remaining check is for compatible
+  // pointer categories.
+
+  if (SrcType->isFunctionPointerType()) {
+    if (DestType->isFunctionPointerType()) {
+      // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
+      // a pointer to a function of a different type.
+      return;
+    }
+
+    // FIXME: Handle member pointers.
+
+    // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
+    //   an object type or vice versa is conditionally-supported.
+    // Compilers support it in C++03 too, though, because it's necessary for
+    // casting the return value of dlsym() and GetProcAddress().
+    // FIXME: Conditionally-supported behavior should be configurable in the
+    // TargetInfo or similar.
+    if (!Self.getLangOptions().CPlusPlus0x) {
+      Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj, OpRange);
+    }
+    return;
+  }
+
+  // FIXME: Handle member pointers.
+
+  if (DestType->isFunctionPointerType()) {
+    // See above.
+    if (!Self.getLangOptions().CPlusPlus0x) {
+      Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj, OpRange);
+    }
+    return;
+  }
+
+  // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
+  //   a pointer to an object of different type.
+  // Void pointers are not specified, but supported by every compiler out there.
+  // So we finish by allowing everything that remains - it's got to be two
+  // object pointers.
+}
+
+/// CastsAwayConstness - Check if the pointer conversion from SrcType
+/// to DestType casts away constness as defined in C++
+/// 5.2.11p8ff. This is used by the cast checkers.  Both arguments
+/// must denote pointer types.
+bool
+CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType)
+{
+ // Casting away constness is defined in C++ 5.2.11p8 with reference to
+  // C++ 4.4.
+  // We piggyback on Sema::IsQualificationConversion for this, since the rules
+  // are non-trivial. So first we construct Tcv *...cv* as described in
+  // C++ 5.2.11p8.
+
+  QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
+  typedef llvm::SmallVector<unsigned, 8> CvVector;
+  CvVector cv1, cv2;
+
+  // Find the qualifications.
+  while (Self.UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
+    cv1.push_back(UnwrappedSrcType.getCVRQualifiers());
+    cv2.push_back(UnwrappedDestType.getCVRQualifiers());
+  }
+  assert(cv1.size() > 0 && "Must have at least one pointer level.");
+
+  // Construct void pointers with those qualifiers (in reverse order of
+  // unwrapping, of course).
+  QualType SrcConstruct = Self.Context.VoidTy;
+  QualType DestConstruct = Self.Context.VoidTy;
+  for (CvVector::reverse_iterator i1 = cv1.rbegin(), i2 = cv2.rbegin();
+       i1 != cv1.rend(); ++i1, ++i2)
+  {
+    SrcConstruct = Self.Context.getPointerType(
+      SrcConstruct.getQualifiedType(*i1));
+    DestConstruct = Self.Context.getPointerType(
+      DestConstruct.getQualifiedType(*i2));
+  }
+
+  // Test if they're compatible.
+  return SrcConstruct != DestConstruct &&
+    !Self.IsQualificationConversion(SrcConstruct, DestConstruct);
+}
+
+/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
+/// implicit conversions explicit and getting rid of data loss warnings.
+void
+CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                const SourceRange &OpRange)
+{
+  // The order the tests is not entirely arbitrary. There is one conversion
+  // that can be handled in two different ways. Given:
+  // struct A {};
+  // struct B : public A {
+  //   B(); B(const A&);
+  // };
+  // const A &a = B();
+  // the cast static_cast<const B&>(a) could be seen as either a static
+  // reference downcast, or an explicit invocation of the user-defined
+  // conversion using B's conversion constructor.
+  // DR 427 specifies that the downcast is to be applied here.
+
+  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
+  if (DestType->isVoidType()) {
+    return;
+  }
+
+  // C++ 5.2.9p5, reference downcast.
+  // See the function for details.
+  // DR 427 specifies that this is to be applied before paragraph 2.
+  if (IsStaticReferenceDowncast(Self, SrcExpr, DestType)) {
+    return;
+  }
+
+  // C++ 5.2.9p2: An expression e can be explicitly converted to a type T
+  //   [...] if the declaration "T t(e);" is well-formed, [...].
+  ImplicitConversionSequence ICS = TryDirectInitialization(Self, SrcExpr,
+    DestType);
+  if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion) {
+    assert(ICS.ConversionKind != ImplicitConversionSequence::EllipsisConversion
+      && "Direct initialization cannot result in ellipsis conversion");
+    // UserDefinedConversionSequence has a StandardConversionSequence as a
+    // prefix. Accessing Standard is therefore safe.
+    // FIXME: Of course, this is definitely not enough.
+    if(ICS.Standard.First != ICK_Identity) {
+      Self.DefaultFunctionArrayConversion(SrcExpr);
+    }
+    // FIXME: Test the details, such as accessible base.
+    return;
+  }
+
+  // C++ 5.2.9p6: May apply the reverse of any standard conversion, except
+  // lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
+  // conversions, subject to further restrictions.
+  // Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
+  // of qualification conversions impossible.
+
+  // The lvalue-to-rvalue, array-to-pointer and function-to-pointer conversions
+  // are applied to the expression.
+  QualType OrigSrcType = SrcExpr->getType();
+  Self.DefaultFunctionArrayConversion(SrcExpr);
+
+  QualType SrcType = Self.Context.getCanonicalType(SrcExpr->getType());
+
+  // Reverse integral promotion/conversion. All such conversions are themselves
+  // again integral promotions or conversions and are thus already handled by
+  // p2 (TryDirectInitialization above).
+  // (Note: any data loss warnings should be suppressed.)
+  // The exception is the reverse of enum->integer, i.e. integer->enum (and
+  // enum->enum). See also C++ 5.2.9p7.
+  // The same goes for reverse floating point promotion/conversion and
+  // floating-integral conversions. Again, only floating->enum is relevant.
+  if (DestType->isEnumeralType()) {
+    if (SrcType->isComplexType() || SrcType->isVectorType()) {
+      // Fall through - these cannot be converted.
+    } else if (SrcType->isArithmeticType() || SrcType->isEnumeralType()) {
+      return;
+    }
+  }
+
+  // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
+  // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
+  if (IsStaticPointerDowncast(Self, SrcType, DestType)) {
+    return;
+  }
+
+  // Reverse member pointer conversion. C++ 5.11 specifies member pointer
+  // conversion. C++ 5.2.9p9 has additional information.
+  // DR54's access restrictions apply here also.
+  // FIXME: Don't have member pointers yet.
+
+  // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
+  // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
+  // just the usual constness stuff.
+  if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
+    QualType SrcPointee = SrcPointer->getPointeeType();
+    if (SrcPointee->isVoidType()) {
+      if (const PointerType *DestPointer = DestType->getAsPointerType()) {
+        QualType DestPointee = DestPointer->getPointeeType();
+        if (DestPointee->isObjectType()) {
+          // This is definitely the intended conversion, but it might fail due
+          // to a const violation.
+          if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
+            Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away,
+              "static_cast", DestType.getAsString(),
+              OrigSrcType.getAsString(), OpRange);
+          }
+          return;
+        }
+      }
+    }
+  }
+
+  // We tried everything. Everything! Nothing works! :-(
+  // FIXME: Error reporting could be a lot better. Should store the reason
+  // why every substep failed and, at the end, select the most specific and
+  // report that.
+  Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "static_cast",
+    DestType.getAsString(), OrigSrcType.getAsString(), OpRange);
+}
+
+/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
+bool
+IsStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType)
+{
+  // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
+  //   cast to type "reference to cv2 D", where D is a class derived from B,
+  //   if a valid standard conversion from "pointer to D" to "pointer to B"
+  //   exists, cv2 >= cv1, and B is not a virtual base class of D.
+  // In addition, DR54 clarifies that the base must be accessible in the
+  // current context. Although the wording of DR54 only applies to the pointer
+  // variant of this rule, the intent is clearly for it to apply to the this
+  // conversion as well.
+
+  if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
+    return false;
+  }
+
+  const ReferenceType *DestReference = DestType->getAsReferenceType();
+  if (!DestReference) {
+    return false;
+  }
+  QualType DestPointee = DestReference->getPointeeType();
+
+  return IsStaticDowncast(Self, SrcExpr->getType(), DestPointee);
+}
+
+/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
+bool
+IsStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType)
+{
+  // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
+  //   type, can be converted to an rvalue of type "pointer to cv2 D", where D
+  //   is a class derived from B, if a valid standard conversion from "pointer
+  //   to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
+  //   class of D.
+  // In addition, DR54 clarifies that the base must be accessible in the
+  // current context.
+
+  const PointerType *SrcPointer = SrcType->getAsPointerType();
+  if (!SrcPointer) {
+    return false;
+  }
+
+  const PointerType *DestPointer = DestType->getAsPointerType();
+  if (!DestPointer) {
+    return false;
+  }
+
+  return IsStaticDowncast(Self, SrcPointer->getPointeeType(),
+                                DestPointer->getPointeeType());
+}
+
+/// IsStaticDowncast - Common functionality of IsStaticReferenceDowncast and
+/// IsStaticPointerDowncast. Tests whether a static downcast from SrcType to
+/// DestType, both of which must be canonical, is possible and allowed.
+bool
+IsStaticDowncast(Sema &Self, QualType SrcType, QualType DestType)
+{
+  // Downcast can only happen in class hierarchies, so we need classes.
+  if (!DestType->isRecordType() || !SrcType->isRecordType()) {
+    return false;
+  }
+
+  // Comparing cv is cheaper, so do it first.
+  if (!DestType.isAtLeastAsQualifiedAs(SrcType)) {
+    return false;
+  }
+
+  BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
+                  /*DetectVirtual=*/true);
+  if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
+    return false;
+  }
+
+  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
+    return false;
+  }
+
+  if (Paths.getDetectedVirtual() != 0) {
+    return false;
+  }
+
+  // FIXME: Test accessibility.
+
+  return true;
+}
+
+/// TryDirectInitialization - Attempt to direct-initialize a value of the
+/// given type (DestType) from the given expression (SrcExpr), as one would
+/// do when creating an object with new with parameters. This function returns
+/// an implicit conversion sequence that can be used to perform the
+/// initialization.
+/// This routine is very similar to TryCopyInitialization; the differences
+/// between the two (C++ 8.5p12 and C++ 8.5p14) are:
+/// 1) In direct-initialization, all constructors of the target type are
+///    considered, including those marked as explicit.
+/// 2) In direct-initialization, overload resolution is performed over the
+///    constructors of the target type. In copy-initialization, overload
+///    resolution is performed over all conversion functions that result in
+///    the target type. This can lead to different functions used.
+ImplicitConversionSequence
+TryDirectInitialization(Sema &Self, Expr *SrcExpr, QualType DestType)
+{
+  if (!DestType->isRecordType()) {
+    // For non-class types, copy and direct initialization are identical.
+    // C++ 8.5p11
+    // FIXME: Those parts should be in a common function, actually.
+    return Self.TryCopyInitialization(SrcExpr, DestType);
+  }
+
+  // FIXME: Not enough support for the rest yet, actually.
+  ImplicitConversionSequence ICS;
+  ICS.ConversionKind = ImplicitConversionSequence::BadConversion;
+  return ICS;
+}
+
+/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
+/// checked downcasts in class hierarchies.
+void
+CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
+                 const SourceRange &OpRange, const SourceRange &DestRange)
+{
+  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+  DestType = Self.Context.getCanonicalType(DestType);
+
+  // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
+  //   or "pointer to cv void".
+
+  QualType DestPointee;
+  const PointerType *DestPointer = DestType->getAsPointerType();
+  const ReferenceType *DestReference = DestType->getAsReferenceType();
+  if (DestPointer) {
+    DestPointee = DestPointer->getPointeeType();
+  } else if (DestReference) {
+    DestPointee = DestReference->getPointeeType();
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr,
+      OrigDestType.getAsString(), DestRange);
+    return;
+  }
+
+  const RecordType *DestRecord = DestPointee->getAsRecordType();
+  if (DestPointee->isVoidType()) {
+    assert(DestPointer && "Reference to void is not possible");
+  } else if (DestRecord) {
+    if (!DestRecord->getDecl()->isDefinition()) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_incomplete,
+        DestPointee.getUnqualifiedType().getAsString(), DestRange);
+      return;
+    }
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class,
+      DestPointee.getUnqualifiedType().getAsString(), DestRange);
+    return;
+  }
+
+  // C++ 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
+  //   complete class type, [...]. If T is a reference type, v shall be an
+  //   lvalue of a complete class type, [...].
+
+  QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
+  QualType SrcPointee;
+  if (DestPointer) {
+    if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
+      SrcPointee = SrcPointer->getPointeeType();
+    } else {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr,
+        OrigSrcType.getAsString(), SrcExpr->getSourceRange());
+      return;
+    }
+  } else {
+    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue,
+        "dynamic_cast", OrigDestType.getAsString(), OpRange);
+    }
+    SrcPointee = SrcType;
+  }
+
+  const RecordType *SrcRecord = SrcPointee->getAsRecordType();
+  if (SrcRecord) {
+    if (!SrcRecord->getDecl()->isDefinition()) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_incomplete,
+        SrcPointee.getUnqualifiedType().getAsString(),
+        SrcExpr->getSourceRange());
+      return;
+    }
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class,
+      SrcPointee.getUnqualifiedType().getAsString(),
+      SrcExpr->getSourceRange());
+    return;
+  }
+
+  assert((DestPointer || DestReference) &&
+    "Bad destination non-ptr/ref slipped through.");
+  assert((DestRecord || DestPointee->isVoidType()) &&
+    "Bad destination pointee slipped through.");
+  assert(SrcRecord && "Bad source pointee slipped through.");
+
+  // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
+  if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away,
+      "dynamic_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
+      OpRange);
+    return;
+  }
+
+  // C++ 5.2.7p3: If the type of v is the same as the required result type,
+  //   [except for cv].
+  if (DestRecord == SrcRecord) {
+    return;
+  }
+
+  // C++ 5.2.7p5
+  // Upcasts are resolved statically.
+  if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
+    Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
+      OpRange.getBegin(), OpRange);
+    // Diagnostic already emitted on error.
+    return;
+  }
+
+  // C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
+  // FIXME: Information not yet available.
+
+  // Done. Everything else is run-time checks.
+}
+
Index: lib/Sema/SemaExprCXX.cpp
===================================================================
--- lib/Sema/SemaExprCXX.cpp	(revision 58762)
+++ lib/Sema/SemaExprCXX.cpp	(working copy)
@@ -12,673 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "Sema.h"
-#include "SemaInherit.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/Parse/DeclSpec.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Basic/Diagnostic.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Debug.h"
 using namespace clang;
 
-/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
-Action::ExprResult
-Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
-                        SourceLocation LAngleBracketLoc, TypeTy *Ty,
-                        SourceLocation RAngleBracketLoc,
-                        SourceLocation LParenLoc, ExprTy *E,
-                        SourceLocation RParenLoc) {
-  Expr *Ex = (Expr*)E;
-  QualType DestType = QualType::getFromOpaquePtr(Ty);
-  SourceRange OpRange(OpLoc, RParenLoc);
-  SourceRange DestRange(LAngleBracketLoc, RAngleBracketLoc);
-
-  switch (Kind) {
-  default: assert(0 && "Unknown C++ cast!");
-
-  case tok::kw_const_cast:
-    CheckConstCast(Ex, DestType, OpRange, DestRange);
-    return new CXXConstCastExpr(DestType.getNonReferenceType(), Ex, 
-                                DestType, OpLoc);
-
-  case tok::kw_dynamic_cast:
-    CheckDynamicCast(Ex, DestType, OpRange, DestRange);
-    return new CXXDynamicCastExpr(DestType.getNonReferenceType(), Ex, 
-                                  DestType, OpLoc);
-
-  case tok::kw_reinterpret_cast:
-    CheckReinterpretCast(Ex, DestType, OpRange, DestRange);
-    return new CXXReinterpretCastExpr(DestType.getNonReferenceType(), Ex, 
-                                      DestType, OpLoc);
-
-  case tok::kw_static_cast:
-    CheckStaticCast(Ex, DestType, OpRange);
-    return new CXXStaticCastExpr(DestType.getNonReferenceType(), Ex, 
-                                 DestType, OpLoc);
-  }
-
-  return true;
-}
-
-/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
-/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
-/// like this:
-/// const char *str = "literal";
-/// legacy_function(const_cast\<char*\>(str));
-void
-Sema::CheckConstCast(Expr *&SrcExpr, QualType DestType,
-                     const SourceRange &OpRange, const SourceRange &DestRange)
-{
-  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
-
-  DestType = Context.getCanonicalType(DestType);
-  QualType SrcType = SrcExpr->getType();
-  if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
-    if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
-      // Cannot cast non-lvalue to reference type.
-      Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue,
-        "const_cast", OrigDestType.getAsString(), SrcExpr->getSourceRange());
-      return;
-    }
-
-    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
-    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
-    DestType = Context.getPointerType(DestTypeTmp->getPointeeType());
-    SrcType = Context.getPointerType(SrcType);
-  } else {
-    // C++ 5.2.11p1: Otherwise, the result is an rvalue and the
-    //   lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
-    //   conversions are performed on the expression.
-    DefaultFunctionArrayConversion(SrcExpr);
-    SrcType = SrcExpr->getType();
-  }
-
-  if (!DestType->isPointerType()) {
-    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
-    // was a reference type, we converted it to a pointer above.
-    // C++ 5.2.11p3: For two pointer types [...]
-    Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest,
-      OrigDestType.getAsString(), DestRange);
-    return;
-  }
-  if (DestType->isFunctionPointerType()) {
-    // Cannot cast direct function pointers.
-    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
-    // T is the ultimate pointee of source and target type.
-    Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest,
-      OrigDestType.getAsString(), DestRange);
-    return;
-  }
-  SrcType = Context.getCanonicalType(SrcType);
-
-  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
-  // completely equal.
-  // FIXME: const_cast should probably not be able to convert between pointers
-  // to different address spaces.
-  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
-  // in multi-level pointers may change, but the level count must be the same,
-  // as must be the final pointee type.
-  while (SrcType != DestType && UnwrapSimilarPointerTypes(SrcType, DestType)) {
-    SrcType = SrcType.getUnqualifiedType();
-    DestType = DestType.getUnqualifiedType();
-  }
-
-  // Doug Gregor said to disallow this until users complain.
-#if 0
-  // If we end up with constant arrays of equal size, unwrap those too. A cast
-  // from const int [N] to int (&)[N] is invalid by my reading of the
-  // standard, but g++ accepts it even with -ansi -pedantic.
-  // No more than one level, though, so don't embed this in the unwrap loop
-  // above.
-  const ConstantArrayType *SrcTypeArr, *DestTypeArr;
-  if ((SrcTypeArr = Context.getAsConstantArrayType(SrcType)) &&
-     (DestTypeArr = Context.getAsConstantArrayType(DestType)))
-  {
-    if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
-      // Different array sizes.
-      Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "const_cast",
-        OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-      return;
-    }
-    SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
-    DestType = DestTypeArr->getElementType().getUnqualifiedType();
-  }
-#endif
-
-  // Since we're dealing in canonical types, the remainder must be the same.
-  if (SrcType != DestType) {
-    // Cast between unrelated types.
-    Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "const_cast",
-      OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-    return;
-  }
-}
-
-/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
-/// valid.
-/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
-/// like this:
-/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
-void
-Sema::CheckReinterpretCast(Expr *&SrcExpr, QualType DestType,
-                           const SourceRange &OpRange,
-                           const SourceRange &DestRange)
-{
-  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
-
-  DestType = Context.getCanonicalType(DestType);
-  QualType SrcType = SrcExpr->getType();
-  if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
-    if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
-      // Cannot cast non-lvalue to reference type.
-      Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue,
-        "reinterpret_cast", OrigDestType.getAsString(),
-        SrcExpr->getSourceRange());
-      return;
-    }
-
-    // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
-    //   same effect as the conversion *reinterpret_cast<T*>(&x) with the
-    //   built-in & and * operators.
-    // This code does this transformation for the checked types.
-    DestType = Context.getPointerType(DestTypeTmp->getPointeeType());
-    SrcType = Context.getPointerType(SrcType);
-  } else {
-    // C++ 5.2.10p1: [...] the lvalue-to-rvalue, array-to-pointer, and
-    //   function-to-pointer standard conversions are performed on the
-    //   expression v.
-    DefaultFunctionArrayConversion(SrcExpr);
-    SrcType = SrcExpr->getType();
-  }
-
-  // Canonicalize source for comparison.
-  SrcType = Context.getCanonicalType(SrcType);
-
-  bool destIsPtr = DestType->isPointerType();
-  bool srcIsPtr = SrcType->isPointerType();
-  if (!destIsPtr && !srcIsPtr) {
-    // Except for std::nullptr_t->integer, which is not supported yet, and
-    // lvalue->reference, which is handled above, at least one of the two
-    // arguments must be a pointer.
-    Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "reinterpret_cast",
-      OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-    return;
-  }
-
-  if (SrcType == DestType) {
-    // C++ 5.2.10p2 has a note that mentions that, subject to all other
-    // restrictions, a cast to the same type is allowed. The intent is not
-    // entirely clear here, since all other paragraphs explicitly forbid casts
-    // to the same type. However, the behavior of compilers is pretty consistent
-    // on this point: allow same-type conversion if the involved are pointers,
-    // disallow otherwise.
-    return;
-  }
-
-  // Note: Clang treats enumeration types as integral types. If this is ever
-  // changed for C++, the additional check here will be redundant.
-  if (DestType->isIntegralType() && !DestType->isEnumeralType()) {
-    assert(srcIsPtr);
-    // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
-    //   type large enough to hold it.
-    if (Context.getTypeSize(SrcType) > Context.getTypeSize(DestType)) {
-      Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int,
-        OrigDestType.getAsString(), DestRange);
-    }
-    return;
-  }
-
-  if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
-    assert(destIsPtr);
-    // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
-    //   converted to a pointer.
-    return;
-  }
-
-  if (!destIsPtr || !srcIsPtr) {
-    // With the valid non-pointer conversions out of the way, we can be even
-    // more stringent.
-    Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "reinterpret_cast",
-      OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-    return;
-  }
-
-  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
-  if (CastsAwayConstness(SrcType, DestType)) {
-    Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away,
-      "reinterpret_cast", OrigDestType.getAsString(), OrigSrcType.getAsString(),
-      OpRange);
-    return;
-  }
-
-  // Not casting away constness, so the only remaining check is for compatible
-  // pointer categories.
-
-  if (SrcType->isFunctionPointerType()) {
-    if (DestType->isFunctionPointerType()) {
-      // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
-      // a pointer to a function of a different type.
-      return;
-    }
-
-    // FIXME: Handle member pointers.
-
-    // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
-    //   an object type or vice versa is conditionally-supported.
-    // Compilers support it in C++03 too, though, because it's necessary for
-    // casting the return value of dlsym() and GetProcAddress().
-    // FIXME: Conditionally-supported behavior should be configurable in the
-    // TargetInfo or similar.
-    if (!getLangOptions().CPlusPlus0x) {
-      Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj, OpRange);
-    }
-    return;
-  }
-
-  // FIXME: Handle member pointers.
-
-  if (DestType->isFunctionPointerType()) {
-    // See above.
-    if (!getLangOptions().CPlusPlus0x) {
-      Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj, OpRange);
-    }
-    return;
-  }
-
-  // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
-  //   a pointer to an object of different type.
-  // Void pointers are not specified, but supported by every compiler out there.
-  // So we finish by allowing everything that remains - it's got to be two
-  // object pointers.
-}
-
-/// CastsAwayConstness - Check if the pointer conversion from SrcType
-/// to DestType casts away constness as defined in C++
-/// 5.2.11p8ff. This is used by the cast checkers.  Both arguments
-/// must denote pointer types.
-bool
-Sema::CastsAwayConstness(QualType SrcType, QualType DestType)
-{
- // Casting away constness is defined in C++ 5.2.11p8 with reference to
-  // C++ 4.4.
-  // We piggyback on Sema::IsQualificationConversion for this, since the rules
-  // are non-trivial. So first we construct Tcv *...cv* as described in
-  // C++ 5.2.11p8.
-
-  QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
-  llvm::SmallVector<unsigned, 8> cv1, cv2;
-
-  // Find the qualifications.
-  while (UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
-    cv1.push_back(UnwrappedSrcType.getCVRQualifiers());
-    cv2.push_back(UnwrappedDestType.getCVRQualifiers());
-  }
-  assert(cv1.size() > 0 && "Must have at least one pointer level.");
-
-  // Construct void pointers with those qualifiers (in reverse order of
-  // unwrapping, of course).
-  QualType SrcConstruct = Context.VoidTy;
-  QualType DestConstruct = Context.VoidTy;
-  for (llvm::SmallVector<unsigned, 8>::reverse_iterator i1 = cv1.rbegin(),
-                                                        i2 = cv2.rbegin();
-       i1 != cv1.rend(); ++i1, ++i2)
-  {
-    SrcConstruct = Context.getPointerType(SrcConstruct.getQualifiedType(*i1));
-    DestConstruct = Context.getPointerType(DestConstruct.getQualifiedType(*i2));
-  }
-
-  // Test if they're compatible.
-  return SrcConstruct != DestConstruct &&
-    !IsQualificationConversion(SrcConstruct, DestConstruct);
-}
-
-/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
-/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
-/// implicit conversions explicit and getting rid of data loss warnings.
-void
-Sema::CheckStaticCast(Expr *&SrcExpr, QualType DestType,
-                      const SourceRange &OpRange)
-{
-  // The order the tests is not entirely arbitrary. There is one conversion
-  // that can be handled in two different ways. Given:
-  // struct A {};
-  // struct B : public A {
-  //   B(); B(const A&);
-  // };
-  // const A &a = B();
-  // the cast static_cast<const B&>(a) could be seen as either a static
-  // reference downcast, or an explicit invocation of the user-defined
-  // conversion using B's conversion constructor.
-  // DR 427 specifies that the downcast is to be applied here.
-
-  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
-  if (DestType->isVoidType()) {
-    return;
-  }
-
-  // C++ 5.2.9p5, reference downcast.
-  // See the function for details.
-  // DR 427 specifies that this is to be applied before paragraph 2.
-  if (IsStaticReferenceDowncast(SrcExpr, DestType)) {
-    return;
-  }
-
-  // C++ 5.2.9p2: An expression e can be explicitly converted to a type T
-  //   [...] if the declaration "T t(e);" is well-formed, [...].
-  ImplicitConversionSequence ICS = TryDirectInitialization(SrcExpr, DestType);
-  if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion) {
-    assert(ICS.ConversionKind != ImplicitConversionSequence::EllipsisConversion
-      && "Direct initialization cannot result in ellipsis conversion");
-    // UserDefinedConversionSequence has a StandardConversionSequence as a
-    // prefix. Accessing Standard is therefore safe.
-    // FIXME: Of course, this is definitely not enough.
-    if(ICS.Standard.First != ICK_Identity) {
-      DefaultFunctionArrayConversion(SrcExpr);
-    }
-    // FIXME: Test the details, such as accessible base.
-    return;
-  }
-
-  // C++ 5.2.9p6: May apply the reverse of any standard conversion, except
-  // lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
-  // conversions, subject to further restrictions.
-  // Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
-  // of qualification conversions impossible.
-
-  // The lvalue-to-rvalue, array-to-pointer and function-to-pointer conversions
-  // are applied to the expression.
-  QualType OrigSrcType = SrcExpr->getType();
-  DefaultFunctionArrayConversion(SrcExpr);
-
-  QualType SrcType = Context.getCanonicalType(SrcExpr->getType());
-
-  // Reverse integral promotion/conversion. All such conversions are themselves
-  // again integral promotions or conversions and are thus already handled by
-  // p2 (TryDirectInitialization above).
-  // (Note: any data loss warnings should be suppressed.)
-  // The exception is the reverse of enum->integer, i.e. integer->enum (and
-  // enum->enum). See also C++ 5.2.9p7.
-  // The same goes for reverse floating point promotion/conversion and
-  // floating-integral conversions. Again, only floating->enum is relevant.
-  if (DestType->isEnumeralType()) {
-    if (SrcType->isComplexType() || SrcType->isVectorType()) {
-      // Fall through - these cannot be converted.
-    } else if (SrcType->isArithmeticType() || SrcType->isEnumeralType()) {
-      return;
-    }
-  }
-
-  // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
-  // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
-  if (IsStaticPointerDowncast(SrcType, DestType)) {
-    return;
-  }
-
-  // Reverse member pointer conversion. C++ 5.11 specifies member pointer
-  // conversion. C++ 5.2.9p9 has additional information.
-  // DR54's access restrictions apply here also.
-  // FIXME: Don't have member pointers yet.
-
-  // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
-  // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
-  // just the usual constness stuff.
-  if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
-    QualType SrcPointee = SrcPointer->getPointeeType();
-    if (SrcPointee->isVoidType()) {
-      if (const PointerType *DestPointer = DestType->getAsPointerType()) {
-        QualType DestPointee = DestPointer->getPointeeType();
-        if (DestPointee->isObjectType()) {
-          // This is definitely the intended conversion, but it might fail due
-          // to a const violation.
-          if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
-            Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away,
-              "static_cast", DestType.getAsString(),
-              OrigSrcType.getAsString(), OpRange);
-          }
-          return;
-        }
-      }
-    }
-  }
-
-  // We tried everything. Everything! Nothing works! :-(
-  // FIXME: Error reporting could be a lot better. Should store the reason
-  // why every substep failed and, at the end, select the most specific and
-  // report that.
-  Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic, "static_cast",
-    DestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-}
-
-/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
-bool
-Sema::IsStaticReferenceDowncast(Expr *SrcExpr, QualType DestType)
-{
-  // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
-  //   cast to type "reference to cv2 D", where D is a class derived from B,
-  //   if a valid standard conversion from "pointer to D" to "pointer to B"
-  //   exists, cv2 >= cv1, and B is not a virtual base class of D.
-  // In addition, DR54 clarifies that the base must be accessible in the
-  // current context. Although the wording of DR54 only applies to the pointer
-  // variant of this rule, the intent is clearly for it to apply to the this
-  // conversion as well.
-
-  if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
-    return false;
-  }
-
-  const ReferenceType *DestReference = DestType->getAsReferenceType();
-  if (!DestReference) {
-    return false;
-  }
-  QualType DestPointee = DestReference->getPointeeType();
-
-  return IsStaticDowncast(SrcExpr->getType(), DestPointee);
-}
-
-/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
-bool
-Sema::IsStaticPointerDowncast(QualType SrcType, QualType DestType)
-{
-  // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
-  //   type, can be converted to an rvalue of type "pointer to cv2 D", where D
-  //   is a class derived from B, if a valid standard conversion from "pointer
-  //   to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
-  //   class of D.
-  // In addition, DR54 clarifies that the base must be accessible in the
-  // current context.
-
-  const PointerType *SrcPointer = SrcType->getAsPointerType();
-  if (!SrcPointer) {
-    return false;
-  }
-
-  const PointerType *DestPointer = DestType->getAsPointerType();
-  if (!DestPointer) {
-    return false;
-  }
-
-  return IsStaticDowncast(SrcPointer->getPointeeType(),
-                          DestPointer->getPointeeType());
-}
-
-/// IsStaticDowncast - Common functionality of IsStaticReferenceDowncast and
-/// IsStaticPointerDowncast. Tests whether a static downcast from SrcType to
-/// DestType, both of which must be canonical, is possible and allowed.
-bool
-Sema::IsStaticDowncast(QualType SrcType, QualType DestType)
-{
-  // Downcast can only happen in class hierarchies, so we need classes.
-  if (!DestType->isRecordType() || !SrcType->isRecordType()) {
-    return false;
-  }
-
-  // Comparing cv is cheaper, so do it first.
-  if (!DestType.isAtLeastAsQualifiedAs(SrcType)) {
-    return false;
-  }
-
-  BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
-                  /*DetectVirtual=*/true);
-  if (!IsDerivedFrom(DestType, SrcType, Paths)) {
-    return false;
-  }
-
-  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
-    return false;
-  }
-
-  if (Paths.getDetectedVirtual() != 0) {
-    return false;
-  }
-
-  // FIXME: Test accessibility.
-
-  return true;
-}
-
-/// TryDirectInitialization - Attempt to direct-initialize a value of the
-/// given type (DestType) from the given expression (SrcExpr), as one would
-/// do when creating an object with new with parameters. This function returns
-/// an implicit conversion sequence that can be used to perform the
-/// initialization.
-/// This routine is very similar to TryCopyInitialization; the differences
-/// between the two (C++ 8.5p12 and C++ 8.5p14) are:
-/// 1) In direct-initialization, all constructors of the target type are
-///    considered, including those marked as explicit.
-/// 2) In direct-initialization, overload resolution is performed over the
-///    constructors of the target type. In copy-initialization, overload
-///    resolution is performed over all conversion functions that result in
-///    the target type. This can lead to different functions used.
-ImplicitConversionSequence
-Sema::TryDirectInitialization(Expr *SrcExpr, QualType DestType)
-{
-  if (!DestType->isRecordType()) {
-    // For non-class types, copy and direct initialization are identical.
-    // C++ 8.5p11
-    // FIXME: Those parts should be in a common function, actually.
-    return TryCopyInitialization(SrcExpr, DestType);
-  }
-
-  // FIXME: Not enough support for the rest yet, actually.
-  ImplicitConversionSequence ICS;
-  ICS.ConversionKind = ImplicitConversionSequence::BadConversion;
-  return ICS;
-}
-
-/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
-/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
-/// checked downcasts in class hierarchies.
-void
-Sema::CheckDynamicCast(Expr *&SrcExpr, QualType DestType,
-                       const SourceRange &OpRange,
-                       const SourceRange &DestRange)
-{
-  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
-  DestType = Context.getCanonicalType(DestType);
-
-  // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
-  //   or "pointer to cv void".
-
-  QualType DestPointee;
-  const PointerType *DestPointer = DestType->getAsPointerType();
-  const ReferenceType *DestReference = DestType->getAsReferenceType();
-  if (DestPointer) {
-    DestPointee = DestPointer->getPointeeType();
-  } else if (DestReference) {
-    DestPointee = DestReference->getPointeeType();
-  } else {
-    Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr,
-      OrigDestType.getAsString(), DestRange);
-    return;
-  }
-
-  const RecordType *DestRecord = DestPointee->getAsRecordType();
-  if (DestPointee->isVoidType()) {
-    assert(DestPointer && "Reference to void is not possible");
-  } else if (DestRecord) {
-    if (!DestRecord->getDecl()->isDefinition()) {
-      Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_incomplete,
-        DestPointee.getUnqualifiedType().getAsString(), DestRange);
-      return;
-    }
-  } else {
-    Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class,
-      DestPointee.getUnqualifiedType().getAsString(), DestRange);
-    return;
-  }
-
-  // C++ 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
-  //   complete class type, [...]. If T is a reference type, v shall be an
-  //   lvalue of a complete class type, [...].
-
-  QualType SrcType = Context.getCanonicalType(OrigSrcType);
-  QualType SrcPointee;
-  if (DestPointer) {
-    if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
-      SrcPointee = SrcPointer->getPointeeType();
-    } else {
-      Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr,
-        OrigSrcType.getAsString(), SrcExpr->getSourceRange());
-      return;
-    }
-  } else {
-    if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
-      Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue, "dynamic_cast",
-        OrigDestType.getAsString(), OpRange);
-    }
-    SrcPointee = SrcType;
-  }
-
-  const RecordType *SrcRecord = SrcPointee->getAsRecordType();
-  if (SrcRecord) {
-    if (!SrcRecord->getDecl()->isDefinition()) {
-      Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_incomplete,
-        SrcPointee.getUnqualifiedType().getAsString(),
-        SrcExpr->getSourceRange());
-      return;
-    }
-  } else {
-    Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class,
-      SrcPointee.getUnqualifiedType().getAsString(),
-      SrcExpr->getSourceRange());
-    return;
-  }
-
-  assert((DestPointer || DestReference) &&
-    "Bad destination non-ptr/ref slipped through.");
-  assert((DestRecord || DestPointee->isVoidType()) &&
-    "Bad destination pointee slipped through.");
-  assert(SrcRecord && "Bad source pointee slipped through.");
-
-  // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
-  if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
-    Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away, "dynamic_cast",
-      OrigDestType.getAsString(), OrigSrcType.getAsString(), OpRange);
-    return;
-  }
-
-  // C++ 5.2.7p3: If the type of v is the same as the required result type,
-  //   [except for cv].
-  if (DestRecord == SrcRecord) {
-    return;
-  }
-
-  // C++ 5.2.7p5
-  // Upcasts are resolved statically.
-  if (DestRecord && IsDerivedFrom(SrcPointee, DestPointee)) {
-    CheckDerivedToBaseConversion(SrcPointee, DestPointee, OpRange.getBegin(),
-      OpRange);
-    // Diagnostic already emitted on error.
-    return;
-  }
-
-  // C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
-  // FIXME: Information not yet available.
-
-  // Done. Everything else is run-time checks.
-}
-
 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
 Action::ExprResult
 Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
Index: lib/Sema/Sema.h
===================================================================
--- lib/Sema/Sema.h	(revision 58757)
+++ lib/Sema/Sema.h	(working copy)
@@ -378,7 +378,9 @@
   bool IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
                            QualType& ConvertedType);
   bool CheckPointerConversion(Expr *From, QualType ToType);
+public:
   bool IsQualificationConversion(QualType FromType, QualType ToType);
+private:
   bool IsUserDefinedConversion(Expr *From, QualType ToType, 
                                UserDefinedConversionSequence& User);
 
@@ -398,9 +400,11 @@
   CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1,
                                   const StandardConversionSequence& SCS2);
 
+public:
   ImplicitConversionSequence 
   TryCopyInitialization(Expr* From, QualType ToType,
                         bool SuppressUserConversions = false);
+private:
   bool PerformCopyInitialization(Expr *&From, QualType ToType, 
                                  const char *Flavor);
 
@@ -724,32 +728,14 @@
                                      InitializationKind Kind);
 
   /// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
-  virtual ExprResult ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
-                                       SourceLocation LAngleBracketLoc, TypeTy *Ty,
+  virtual ExprResult ActOnCXXNamedCast(SourceLocation OpLoc,
+                                       tok::TokenKind Kind,
+                                       SourceLocation LAngleBracketLoc,
+                                       TypeTy *Ty,
                                        SourceLocation RAngleBracketLoc,
                                        SourceLocation LParenLoc, ExprTy *E,
                                        SourceLocation RParenLoc);
 
-private:
-  // Helpers for ActOnCXXCasts
-  void CheckConstCast(Expr *&SrcExpr, QualType DestType,
-                      const SourceRange &OpRange, const SourceRange &DestRange);
-  void CheckReinterpretCast(Expr *&SrcExpr, QualType DestType,
-                            const SourceRange &OpRange,
-                            const SourceRange &DestRange);
-  void CheckStaticCast(Expr *&SrcExpr, QualType DestType,
-                       const SourceRange &OpRange);
-  void CheckDynamicCast(Expr *&SrcExpr, QualType DestType,
-                        const SourceRange &OpRange,
-                        const SourceRange &DestRange);
-  bool CastsAwayConstness(QualType SrcType, QualType DestType);
-  bool IsStaticReferenceDowncast(Expr *SrcExpr, QualType DestType);
-  bool IsStaticPointerDowncast(QualType SrcType, QualType DestType);
-  bool IsStaticDowncast(QualType SrcType, QualType DestType);
-  ImplicitConversionSequence TryDirectInitialization(Expr *SrcExpr,
-                                                     QualType DestType);
-
-public:
   //// ActOnCXXThis -  Parse 'this' pointer.
   virtual ExprResult ActOnCXXThis(SourceLocation ThisLoc);
 
@@ -996,11 +982,13 @@
   // UsualUnaryConversionType - Same as UsualUnaryConversions, but works
   // on types instead of expressions
   QualType UsualUnaryConversionType(QualType Ty); 
-  
+
+public:
   // DefaultFunctionArrayConversion - converts functions and arrays
   // to their respective pointers (C99 6.3.2.1). 
   void DefaultFunctionArrayConversion(Expr *&expr);
-  
+
+private:
   // DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that
   // do not have a prototype. Integer promotions are performed on each 
   // argument, and arguments that have type float are promoted to double.
