[cfe-commits] r147973 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaDecl.cpp test/Sema/c11-typedef-redef.c

[Eli Friedman]

On Wed, Jan 11, 2012 at 2:33 PM, Douglas Gregor <dgregor at apple.com> wrote:
> Author: dgregor
> Date: Wed Jan 11 16:33:48 2012
> New Revision: 147973
>
> URL: http://llvm.org/viewvc/llvm-project?rev=147973&view=rev
> Log:
> Improve the diagnostic when trying to redefine a typedef with a
> variably-modified type.
>
> Modified:
>    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>    cfe/trunk/lib/Sema/SemaDecl.cpp
>    cfe/trunk/test/Sema/c11-typedef-redef.c
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=147973&r1=147972&r2=147973&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Jan 11 16:33:48 2012
> @@ -2754,6 +2754,8 @@
>  def warn_redefinition_of_typedef : ExtWarn<
>   "redefinition of typedef %0 is a C11 feature">,
>   InGroup<DiagGroup<"typedef-redefinition"> >;
> +def err_redefinition_variably_modified_typedef : Error<
> +  "redefinition of %select{typedef|type alias}0 for variably-modified type %1">;
>
>  def err_inline_declaration_block_scope : Error<
>   "inline declaration of %0 not allowed in block scope">;
>
> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=147973&r1=147972&r2=147973&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Wed Jan 11 16:33:48 2012
> @@ -1383,10 +1383,21 @@
>     OldType = Context.getTypeDeclType(Old);
>   QualType NewType = New->getUnderlyingType();
>
> +  if (NewType->isVariablyModifiedType()) {
> +    // Must not redefine a typedef with a variably-modified type.
> +    int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
> +    Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
> +      << Kind << NewType;
> +    if (Old->getLocation().isValid())
> +      Diag(Old->getLocation(), diag::note_previous_definition);
> +    New->setInvalidDecl();
> +    return true;
> +  }
> +
>   if (OldType != NewType &&
>       !OldType->isDependentType() &&
>       !NewType->isDependentType() &&
> -      !Context.hasSameType(OldType, NewType)) {
> +      !Context.hasSameType(OldType, NewType)) {
>     int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
>     Diag(New->getLocation(), diag::err_redefinition_different_typedef)
>       << Kind << NewType << OldType;
>
> Modified: cfe/trunk/test/Sema/c11-typedef-redef.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/c11-typedef-redef.c?rev=147973&r1=147972&r2=147973&view=diff
> ==============================================================================
> --- cfe/trunk/test/Sema/c11-typedef-redef.c (original)
> +++ cfe/trunk/test/Sema/c11-typedef-redef.c Wed Jan 11 16:33:48 2012
> @@ -10,5 +10,5 @@
>   typedef int type2;
>
>   typedef int vla[N]; // expected-note{{previous definition is here}}
> -  typedef int vla[N]; // expected-error{{typedef redefinition with different types ('int [N]' vs 'int [N]')}}
> +  typedef int vla[N]; // expected-error{{redefinition of typedef for variably-modified type 'int [N]'}}
>  }

Might be nice to have a testcase for:
typedef int vla[N];
typedef vla vla2;
typedef vla vla2;

-Eli