[cfe-commits] r147925 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaDecl.cpp test/Preprocessor/line-directive.c test/Sema/c11-typedef-redef.c

[Eli Friedman]

On Wed, Jan 11, 2012 at 11:44 AM, Matthieu Monrocq
<matthieu.monrocq at gmail.com> wrote:
>
>
> Le 11 janvier 2012 05:25, Douglas Gregor <dgregor at apple.com> a écrit :
>
>> Author: dgregor
>> Date: Tue Jan 10 22:25:01 2012
>> New Revision: 147925
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=147925&view=rev
>> Log:
>> C11 allows typedefs to be redefined. Implement this in C11 mode, and
>> downgrade the default-error warning to an ExtWarn in
>> C90/99. <rdar://problem/10668057>
>>
>> Added:
>>    cfe/trunk/test/Sema/c11-typedef-redef.c   (with props)
>> Modified:
>>    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>    cfe/trunk/lib/Sema/SemaDecl.cpp
>>    cfe/trunk/test/Preprocessor/line-directive.c
>>
>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=147925&r1=147924&r2=147925&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Jan 10
>> 22:25:01 2012
>> @@ -2751,9 +2751,9 @@
>>   DiagGroup<"undefined-internal">;
>>  def note_used_here : Note<"used here">;
>>
>> -def warn_redefinition_of_typedef : Warning<
>> -  "redefinition of typedef %0 is invalid in C">,
>> -  InGroup<DiagGroup<"typedef-redefinition"> >, DefaultError;
>> +def warn_redefinition_of_typedef : ExtWarn<
>> +  "redefinition of typedef %0 is a C11 feature">,
>> +  InGroup<DiagGroup<"typedef-redefinition"> >;
>>
>>  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=147925&r1=147924&r2=147925&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Tue Jan 10 22:25:01 2012
>> @@ -1463,8 +1463,6 @@
>>
>>   // The types match.  Link up the redeclaration chain if the old
>>   // declaration was a typedef.
>> -  // FIXME: this is a potential source of weirdness if the type
>> -  // spellings don't match exactly.
>>   if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old))
>>     New->setPreviousDeclaration(Typedef);
>>
>> @@ -1509,8 +1507,8 @@
>>     return New->setInvalidDecl();
>>   }
>>
>> -  // Modules always permit redefinition of typedefs.
>> -  if (getLangOptions().Modules)
>> +  // Modules always permit redefinition of typedefs, as does C11.
>> +  if (getLangOptions().Modules || getLangOptions().C11)
>>     return;
>>
>>   // If we have a redefinition of a typedef in C, emit a warning.  This
>> warning
>>
>> Modified: cfe/trunk/test/Preprocessor/line-directive.c
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Preprocessor/line-directive.c?rev=147925&r1=147924&r2=147925&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/test/Preprocessor/line-directive.c (original)
>> +++ cfe/trunk/test/Preprocessor/line-directive.c Tue Jan 10 22:25:01 2012
>> @@ -41,7 +41,7 @@
>>
>>  # 192 "glomp.h" // not a system header.
>>  typedef int x;  // expected-note {{previous definition is here}}
>> -typedef int x;  // expected-error {{redefinition of typedef 'x' is
>> invalid in C}}
>> +typedef int x;  // expected-warning {{redefinition of typedef 'x' is a
>> C11 feature}}
>>
>>  # 192 "glomp.h" 3 // System header.
>>  typedef int y;  // ok
>> @@ -62,7 +62,7 @@
>>  # 42 "blonk.h"  // DOES change system headerness.
>>
>>  typedef int w;  // expected-note {{previous definition is here}}
>> -typedef int w;  // expected-error {{redefinition of typedef 'w' is
>> invalid in C}}
>> +typedef int w;  // expected-warning {{redefinition of typedef 'w' is a
>> C11 feature}}
>>
>>  typedef int q;  // original definition in system header, should not
>> diagnose.
>>
>>
>> Added: cfe/trunk/test/Sema/c11-typedef-redef.c
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/c11-typedef-redef.c?rev=147925&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Sema/c11-typedef-redef.c (added)
>> +++ cfe/trunk/test/Sema/c11-typedef-redef.c Tue Jan 10 22:25:01 2012
>> @@ -0,0 +1,14 @@
>> +// RUN: %clang_cc1 -std=c11 %s -verify
>> +
>> +typedef int type;
>> +typedef type type;
>> +typedef int type;
>> +
>> +void f(int N) {
>> +  typedef int type2;
>> +  typedef type type2;
>> +  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]')}}
>> +}
>>
> Hello Doug,
>
> this last error is very weird:
> - is the error off ?   (ie, it is acceptable to redefine the typedef for vla
> but not handled yet)
> - or is it simply that the diagnostic is unclear ?   (the FOO vs FOO part
> looks strange, the types are identical as far as I can see).

It's just the diagnostic that's a bit unclear.

-Eli