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

[Douglas Gregor]

On Jan 11, 2012, at 2:45 PM, Eli Friedman wrote:

> 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;

That's also ill-formed; added in r147974.

	- Doug