Revert "[clang] Implement -Wcast-qual for C++"

Breaks -Werror builders.

llvm-svn: 305148

1 files changed, 24 insertions, 70 deletions

diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp
index ba2049d8a60..7d534263f46 100644
--- a/clang/lib/Sema/SemaCast.cpp
+++ b/clang/lib/Sema/SemaCast.cpp
@@ -143,9 +143,6 @@ namespace {
   };
 }
 
-static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
-                             QualType DestType);
-
 // The Try functions attempt a specific way of casting. If they succeed, they
 // return TC_Success. If their way of casting is not appropriate for the given
 // arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
@@ -430,10 +427,6 @@ static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType,
 /// the same kind of pointer (plain or to-member). Unlike the Sema function,
 /// this one doesn't care if the two pointers-to-member don't point into the
 /// same class. This is because CastsAwayConstness doesn't care.
-/// And additionally, it handles C++ references. If both the types are
-/// references, then their pointee types are returned,
-/// else if only one of them is reference, it's pointee type is returned,
-/// and the other type is returned as-is.
 static bool UnwrapDissimilarPointerTypes(QualType& T1, QualType& T2) {
   const PointerType *T1PtrType = T1->getAs<PointerType>(),
                     *T2PtrType = T2->getAs<PointerType>();
@@ -482,26 +475,6 @@ static bool UnwrapDissimilarPointerTypes(QualType& T1, QualType& T2) {
     return true;
   }
   
-  const LValueReferenceType *T1RefType = T1->getAs<LValueReferenceType>(),
-                            *T2RefType = T2->getAs<LValueReferenceType>();
-  if (T1RefType && T2RefType) {
-    T1 = T1RefType->getPointeeType();
-    T2 = T2RefType->getPointeeType();
-    return true;
-  }
-
-  if (T1RefType) {
-    T1 = T1RefType->getPointeeType();
-    // T2 = T2;
-    return true;
-  }
-
-  if (T2RefType) {
-    // T1 = T1;
-    T2 = T2RefType->getPointeeType();
-    return true;
-  }
-
   return false;
 }
 
@@ -530,13 +503,11 @@ CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
   // the rules are non-trivial. So first we construct Tcv *...cv* as described
   // in C++ 5.2.11p8.
   assert((SrcType->isAnyPointerType() || SrcType->isMemberPointerType() ||
-          SrcType->isBlockPointerType() ||
-          DestType->isLValueReferenceType()) &&
+          SrcType->isBlockPointerType()) &&
          "Source type is not pointer or pointer to member.");
   assert((DestType->isAnyPointerType() || DestType->isMemberPointerType() ||
-          DestType->isBlockPointerType() ||
-          DestType->isLValueReferenceType()) &&
-         "Destination type is not pointer or pointer to member, or reference.");
+          DestType->isBlockPointerType()) &&
+         "Destination type is not pointer or pointer to member.");
 
   QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType), 
            UnwrappedDestType = Self.Context.getCanonicalType(DestType);
@@ -2206,8 +2177,6 @@ static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
 
 void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
                                        bool ListInitialization) {
-  assert(Self.getLangOpts().CPlusPlus);
-
   // Handle placeholders.
   if (isPlaceholder()) {
     // C-style casts can resolve __unknown_any types.
@@ -2611,42 +2580,30 @@ void CastOperation::CheckCStyleCast() {
 
   if (Kind == CK_BitCast)
     checkCastAlign();
-}
-
-/// DiagnoseCastQual - Warn whenever casts discards a qualifiers, be it either
-/// const, volatile or both.
-static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
-                             QualType DestType) {
-  if (SrcExpr.isInvalid())
-    return;
-
-  QualType SrcType = SrcExpr.get()->getType();
-  if (!((SrcType->isAnyPointerType() && DestType->isAnyPointerType()) ||
-        DestType->isLValueReferenceType()))
-    return;
 
+  // -Wcast-qual
   QualType TheOffendingSrcType, TheOffendingDestType;
   Qualifiers CastAwayQualifiers;
-  if (!CastsAwayConstness(Self, SrcType, DestType, true, false,
-                          &TheOffendingSrcType, &TheOffendingDestType,
-                          &CastAwayQualifiers))
-    return;
-
-  int qualifiers = -1;
-  if (CastAwayQualifiers.hasConst() && CastAwayQualifiers.hasVolatile()) {
-    qualifiers = 0;
-  } else if (CastAwayQualifiers.hasConst()) {
-    qualifiers = 1;
-  } else if (CastAwayQualifiers.hasVolatile()) {
-    qualifiers = 2;
-  }
-  // This is a variant of int **x; const int **y = (const int **)x;
-  if (qualifiers == -1)
-    Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual2)
-        << SrcType << DestType;
-  else
-    Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual)
-        << TheOffendingSrcType << TheOffendingDestType << qualifiers;
+  if (SrcType->isAnyPointerType() && DestType->isAnyPointerType() &&
+      CastsAwayConstness(Self, SrcType, DestType, true, false,
+                         &TheOffendingSrcType, &TheOffendingDestType,
+                         &CastAwayQualifiers)) {
+    int qualifiers = -1;
+    if (CastAwayQualifiers.hasConst() && CastAwayQualifiers.hasVolatile()) {
+      qualifiers = 0;
+    } else if (CastAwayQualifiers.hasConst()) {
+      qualifiers = 1;
+    } else if (CastAwayQualifiers.hasVolatile()) {
+      qualifiers = 2;
+    }
+    // This is a variant of int **x; const int **y = (const int **)x;
+    if (qualifiers == -1)
+      Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual2) <<
+        SrcType << DestType;
+    else
+      Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual) <<
+        TheOffendingSrcType << TheOffendingDestType << qualifiers;
+  }
 }
 
 ExprResult Sema::BuildCStyleCastExpr(SourceLocation LPLoc,
@@ -2667,9 +2624,6 @@ ExprResult Sema::BuildCStyleCastExpr(SourceLocation LPLoc,
   if (Op.SrcExpr.isInvalid())
     return ExprError();
 
-  // -Wcast-qual
-  DiagnoseCastQual(Op.Self, Op.SrcExpr, Op.DestType);
-
   return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
                               Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
                               &Op.BasePath, CastTypeInfo, LPLoc, RPLoc));