[cfe-commits] r88848 - in /cfe/trunk: lib/Sema/SemaCXXCast.cpp test/SemaCXX/static-cast.cpp

[Daniel Dunbar]

On Sun, Nov 15, 2009 at 2:20 AM, Douglas Gregor <dgregor at apple.com> wrote:
> Author: dgregor
> Date: Sun Nov 15 03:20:52 2009
> New Revision: 88848
>
> URL: http://llvm.org/viewvc/llvm-project?rev=88848&view=rev
> Log:
> When performing a static downcast as part of a static_cast, make sure
> that we're dealing with canonical types like the documentation say
> (yay, CanQualType). Alas, this is another instance where using
> getQualifiers() on a non-canonical QualType got us in trouble.
>
> Good news: with this fix, Clang can now parse all of its own headers!

Woot! Very cool Doug!

 - Daniel

> Modified:
>    cfe/trunk/lib/Sema/SemaCXXCast.cpp
>    cfe/trunk/test/SemaCXX/static-cast.cpp
>
> Modified: cfe/trunk/lib/Sema/SemaCXXCast.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCXXCast.cpp?rev=88848&r1=88847&r2=88848&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaCXXCast.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaCXXCast.cpp Sun Nov 15 03:20:52 2009
> @@ -77,8 +77,8 @@
>                                               const SourceRange &OpRange,
>                                               unsigned &msg,
>                                               CastExpr::CastKind &Kind);
> -static TryCastResult TryStaticDowncast(Sema &Self, QualType SrcType,
> -                                       QualType DestType, bool CStyle,
> +static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
> +                                       CanQualType DestType, bool CStyle,
>                                        const SourceRange &OpRange,
>                                        QualType OrigSrcType,
>                                        QualType OrigDestType, unsigned &msg,
> @@ -190,7 +190,8 @@
>   assert((DestType->isPointerType() || DestType->isMemberPointerType()) &&
>          "Destination type is not pointer or pointer to member.");
>
> -  QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
> +  QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType),
> +           UnwrappedDestType = Self.Context.getCanonicalType(DestType);
>   llvm::SmallVector<Qualifiers, 8> cv1, cv2;
>
>   // Find the qualifications.
> @@ -573,7 +574,9 @@
>
>   QualType DestPointee = DestReference->getPointeeType();
>
> -  return TryStaticDowncast(Self, SrcExpr->getType(), DestPointee, CStyle,
> +  return TryStaticDowncast(Self,
> +                           Self.Context.getCanonicalType(SrcExpr->getType()),
> +                           Self.Context.getCanonicalType(DestPointee), CStyle,
>                            OpRange, SrcExpr->getType(), DestType, msg, Kind);
>  }
>
> @@ -601,16 +604,17 @@
>     return TC_NotApplicable;
>   }
>
> -  return TryStaticDowncast(Self, SrcPointer->getPointeeType(),
> -                          DestPointer->getPointeeType(), CStyle,
> -                          OpRange, SrcType, DestType, msg, Kind);
> +  return TryStaticDowncast(Self,
> +                   Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
> +                  Self.Context.getCanonicalType(DestPointer->getPointeeType()),
> +                           CStyle, OpRange, SrcType, DestType, msg, Kind);
>  }
>
>  /// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
>  /// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
> -/// DestType, both of which must be canonical, is possible and allowed.
> +/// DestType is possible and allowed.
>  TryCastResult
> -TryStaticDowncast(Sema &Self, QualType SrcType, QualType DestType,
> +TryStaticDowncast(Sema &Self, CanQualType SrcType, CanQualType DestType,
>                   bool CStyle, const SourceRange &OpRange, QualType OrigSrcType,
>                   QualType OrigDestType, unsigned &msg,
>                   CastExpr::CastKind &Kind) {
> @@ -620,7 +624,7 @@
>     return TC_NotApplicable;
>
>   // Downcast can only happen in class hierarchies, so we need classes.
> -  if (!DestType->isRecordType() || !SrcType->isRecordType()) {
> +  if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
>     return TC_NotApplicable;
>   }
>
> @@ -676,12 +680,13 @@
>                                                  EE = PI->rend();
>              EI != EE; ++EI)
>           PathDisplayStr += EI->Base->getType().getAsString() + " -> ";
> -        PathDisplayStr += DestType.getAsString();
> +        PathDisplayStr += QualType(DestType).getAsString();
>       }
>     }
>
>     Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
> -      << SrcType.getUnqualifiedType() << DestType.getUnqualifiedType()
> +      << QualType(SrcType).getUnqualifiedType()
> +      << QualType(DestType).getUnqualifiedType()
>       << PathDisplayStr << OpRange;
>     msg = 0;
>     return TC_Failed;
>
> Modified: cfe/trunk/test/SemaCXX/static-cast.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/static-cast.cpp?rev=88848&r1=88847&r2=88848&view=diff
>
> ==============================================================================
> --- cfe/trunk/test/SemaCXX/static-cast.cpp (original)
> +++ cfe/trunk/test/SemaCXX/static-cast.cpp Sun Nov 15 03:20:52 2009
> @@ -1,5 +1,4 @@
>  // RUN: clang-cc -fsyntax-only -verify -faccess-control %s
> -
>  struct A {};
>  struct B : public A {};             // Single public base.
>  struct C1 : public virtual B {};    // Single virtual base.
> @@ -162,3 +161,20 @@
>  void test_ctor_init() {
>   (void)static_cast<X1>(X1());
>  }
> +
> +// Casting away constness
> +struct X2 {
> +};
> +
> +struct X3 : X2 {
> +};
> +
> +struct X4 {
> +  typedef const X3 X3_typedef;
> +
> +  void f() const {
> +    (void)static_cast<X3_typedef*>(x2);
> +  }
> +
> +  const X2 *x2;
> +};
>
>
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