[cfe-commits] r83133 - in /cfe/trunk: lib/Sema/SemaExprCXX.cpp test/SemaCXX/overloaded-operator.cpp

[Chris Lattner]

On Sep 29, 2009, at 6:01 PM, John McCall wrote:

> Author: rjmccall
> Date: Tue Sep 29 20:01:30 2009
> New Revision: 83133
>
> URL: http://llvm.org/viewvc/llvm-project?rev=83133&view=rev
> Log:
> Detect operator-> chains of arbitrary length.  Use a terrible data  
> structure
> to strike fear into the hearts of CPUs everywhere.

*cough*, SmallPtrSet? :)

-Chris

>
>
> Modified:
>    cfe/trunk/lib/Sema/SemaExprCXX.cpp
>    cfe/trunk/test/SemaCXX/overloaded-operator.cpp
>
> Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=83133&r1=83132&r2=83133&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Tue Sep 29 20:01:30 2009
> @@ -1977,17 +1977,23 @@
>   //   [...] When operator->returns, the operator-> is applied  to  
> the value
>   //   returned, with the original second operand.
>   if (OpKind == tok::arrow) {
> +    // The set of types we've considered so far.
> +    llvm::SmallVector<CanQualType,8> CTypes;
> +    CTypes.push_back(Context.getCanonicalType(BaseType));
> +
>     while (BaseType->isRecordType()) {
>       Base = BuildOverloadedArrowExpr(S, move(Base), BaseExpr- 
> >getExprLoc());
>       BaseExpr = (Expr*)Base.get();
>       if (BaseExpr == NULL)
>         return ExprError();
> -      if (Context.getCanonicalType(BaseExpr->getType()) ==
> -          Context.getCanonicalType(BaseType)) {
> +      BaseType = BaseExpr->getType();
> +      CanQualType CBaseType = Context.getCanonicalType(BaseType);
> +      if (std::find(CTypes.begin(), CTypes.end(), CBaseType) !=  
> CTypes.end()) {
> +        // TODO: note the chain of conversions
>         Diag(OpLoc, diag::err_operator_arrow_circular);
>         return ExprError();
>       }
> -      BaseType = BaseExpr->getType();
> +      CTypes.push_back(CBaseType);
>     }
>   }
>
>
> Modified: cfe/trunk/test/SemaCXX/overloaded-operator.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/overloaded-operator.cpp?rev=83133&r1=83132&r2=83133&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/test/SemaCXX/overloaded-operator.cpp (original)
> +++ cfe/trunk/test/SemaCXX/overloaded-operator.cpp Tue Sep 29  
> 20:01:30 2009
> @@ -224,3 +224,19 @@
>   AX a;
>   a->b = 0; // expected-error {{circular pointer delegation detected}}
> }
> +
> +struct CircA {
> +  struct CircB& operator->();
> +  int val;
> +};
> +struct CircB {
> +  struct CircC& operator->();
> +};
> +struct CircC {
> +  struct CircA& operator->();
> +};
> +
> +void circ() {
> +  CircA a;
> +  a->val = 0; // expected-error {{circular pointer delegation  
> detected}}
> +}
>
>
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