[cfe-commits] r71946 - in /cfe/trunk/lib/Sema: SemaDecl.cpp SemaExpr.cpp

[Douglas Gregor]

On May 16, 2009, at 6:54 AM, Eli Friedman wrote:

> Author: efriedma
> Date: Sat May 16 08:54:38 2009
> New Revision: 71946
>
> URL: http://llvm.org/viewvc/llvm-project?rev=71946&view=rev
> Log:
> Avoid calling mergeTypes in C++.  I think these are the correct C++
> alternatives, but please correct me if I'm wrong.
>
> I eventually plan to assert in mergeTypes that we aren't in C++ mode
> because composite types are fundamentally not a part of C++. The
> remaining callers for code in the regression tests are
> Sema::WarnConflictingTypedMethods and  
> CodeGenFunction::EmitFunctionProlog;
> I'm not quite sure what the correct approach is for those callers.
>
>
> Modified:
>    cfe/trunk/lib/Sema/SemaDecl.cpp
>    cfe/trunk/lib/Sema/SemaExpr.cpp
>
> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=71946&r1=71945&r2=71946&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Sat May 16 08:54:38 2009
> @@ -916,7 +916,13 @@
>   MergeAttributes(New, Old, Context);
>
>   // Merge the types
> -  QualType MergedT = Context.mergeTypes(New->getType(), Old->getType 
> ());
> +  QualType MergedT;
> +  if (getLangOptions().CPlusPlus) {
> +    if (Context.hasSameType(New->getType(), Old->getType()))
> +      MergedT = New->getType();
> +  } else {
> +    MergedT = Context.mergeTypes(New->getType(), Old->getType());
> +  }
>   if (MergedT.isNull()) {
>     Diag(New->getLocation(), diag::err_redefinition_different_type)
>       << New->getDeclName();

This is slightly too strict in C++, because it's okay to redeclare a  
variable that has an incomplete type with a complete type (and vice  
versa). Here's a test case that used to work in C++ but doesn't now:

	extern int array[10];
	extern int array[];
	extern int array[10];


> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=71946&r1=71945&r2=71946&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Sat May 16 08:54:38 2009
> @@ -3727,14 +3727,24 @@
>                                      rex->getType()))
>         return QualType();
>
> -      // Pointee types must be compatible.
> -      if (!Context.typesAreCompatible(
> -              Context.getCanonicalType(lpointee).getUnqualifiedType 
> (),
> -              Context.getCanonicalType(rpointee).getUnqualifiedType 
> ())) {
> -        Diag(Loc, diag::err_typecheck_sub_ptr_compatible)
> -          << lex->getType() << rex->getType()
> -          << lex->getSourceRange() << rex->getSourceRange();
> -        return QualType();
> +      if (getLangOptions().CPlusPlus) {
> +        // Pointee types must be the same: C++ [expr.add]
> +        if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) {
> +          Diag(Loc, diag::err_typecheck_sub_ptr_compatible)
> +            << lex->getType() << rex->getType()
> +            << lex->getSourceRange() << rex->getSourceRange();
> +          return QualType();
> +        }
> +      } else {
> +        // Pointee types must be compatible C99 6.5.6p3
> +        if (!Context.typesAreCompatible(
> +                Context.getCanonicalType 
> (lpointee).getUnqualifiedType(),
> +                Context.getCanonicalType 
> (rpointee).getUnqualifiedType())) {
> +          Diag(Loc, diag::err_typecheck_sub_ptr_compatible)
> +            << lex->getType() << rex->getType()
> +            << lex->getSourceRange() << rex->getSourceRange();
> +          return QualType();
> +        }
>       }

This looks good.

   - Doug