r180909 - Only evaluate __has_feature(c_thread_local) and __has_feature(cxx_thread_local) true when the target supports thread-local storage.

[Jean-Daniel Dupas]

OK.

Thank you for the answer. Last time I checked, I missed the __tlv_atexit call. I'm glad to know C++11 TLS support can work on OS X :-)

Le 2 mai 2013 à 15:17, Douglas Gregor <dgregor at apple.com> a écrit :

> 
> On May 2, 2013, at 1:00 AM, Jean-Daniel Dupas <devlists at shadowlab.org> wrote:
> 
>> Is it OK to use the same condition for both while they don't require the same Target support ? 
>> 
>> AFAK, C++ TLS require __cxa_thread_atexit support, and so the target should support thread_atexit, while C TLS doesn't need it.
> 
> As Richard notes, whether __cxa_thread_atexit is available or not is a library issue, and we don't have visibility into that within the frontend. However, we do know whether the target supports thread-local storage in general (it's part of target information), and my change makes __has_feature(c(xx)?_thread_local) match what Sema actually allows.
> 
>> Actually, I think darwin has support for C thread local, but no C++ thread local.
> 
> x86 Darwin fully supports thread-local, although the __cxa_thread_atexit equivalent is called __tlv_atexit. ARM Darwin does not support thread-local (at all).
> 
> 	- Doug
> 
> 
>> Le 2 mai 2013 à 07:28, Douglas Gregor <dgregor at apple.com> a écrit :
>> 
>>> Author: dgregor
>>> Date: Thu May  2 00:28:32 2013
>>> New Revision: 180909
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=180909&view=rev
>>> Log:
>>> Only evaluate __has_feature(c_thread_local) and __has_feature(cxx_thread_local) true when the target supports thread-local storage.
>>> 
>>> Modified:
>>>  cfe/trunk/lib/Lex/PPMacroExpansion.cpp
>>>  cfe/trunk/test/Lexer/has_feature_cxx0x.cpp
>>> 
>>> Modified: cfe/trunk/lib/Lex/PPMacroExpansion.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/PPMacroExpansion.cpp?rev=180909&r1=180908&r2=180909&view=diff
>>> ==============================================================================
>>> --- cfe/trunk/lib/Lex/PPMacroExpansion.cpp (original)
>>> +++ cfe/trunk/lib/Lex/PPMacroExpansion.cpp Thu May  2 00:28:32 2013
>>> @@ -751,7 +751,8 @@ static bool HasFeature(const Preprocesso
>>>          .Case("c_atomic", LangOpts.C11)
>>>          .Case("c_generic_selections", LangOpts.C11)
>>>          .Case("c_static_assert", LangOpts.C11)
>>> -           .Case("c_thread_local", LangOpts.C11)
>>> +           .Case("c_thread_local", 
>>> +                 LangOpts.C11 && PP.getTargetInfo().isTLSSupported())
>>>          // C++11 features
>>>          .Case("cxx_access_control_sfinae", LangOpts.CPlusPlus11)
>>>          .Case("cxx_alias_templates", LangOpts.CPlusPlus11)
>>> @@ -783,7 +784,8 @@ static bool HasFeature(const Preprocesso
>>>          .Case("cxx_rvalue_references", LangOpts.CPlusPlus11)
>>>          .Case("cxx_strong_enums", LangOpts.CPlusPlus11)
>>>          .Case("cxx_static_assert", LangOpts.CPlusPlus11)
>>> -           .Case("cxx_thread_local", LangOpts.CPlusPlus11)
>>> +           .Case("cxx_thread_local", 
>>> +                 LangOpts.CPlusPlus11 && PP.getTargetInfo().isTLSSupported())
>>>          .Case("cxx_trailing_return", LangOpts.CPlusPlus11)
>>>          .Case("cxx_unicode_literals", LangOpts.CPlusPlus11)
>>>          .Case("cxx_unrestricted_unions", LangOpts.CPlusPlus11)
>>> 
>>> Modified: cfe/trunk/test/Lexer/has_feature_cxx0x.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Lexer/has_feature_cxx0x.cpp?rev=180909&r1=180908&r2=180909&view=diff
>>> ==============================================================================
>>> --- cfe/trunk/test/Lexer/has_feature_cxx0x.cpp (original)
>>> +++ cfe/trunk/test/Lexer/has_feature_cxx0x.cpp Thu May  2 00:28:32 2013
>>> @@ -1,5 +1,6 @@
>>> -// RUN: %clang_cc1 -E -std=c++11 %s -o - | FileCheck --check-prefix=CHECK-0X %s
>>> -// RUN: %clang_cc1 -E %s -o - | FileCheck --check-prefix=CHECK-NO-0X %s
>>> +// RUN: %clang_cc1 -E -triple x86_64-linux-gnu -std=c++11 %s -o - | FileCheck --check-prefix=CHECK-0X %s
>>> +// RUN: %clang_cc1 -E -triple armv7-apple-darwin -std=c++11 %s -o - | FileCheck --check-prefix=CHECK-NO-TLS %s
>>> +// RUN: %clang_cc1 -E -triple x86_64-linux-gnu %s -o - | FileCheck --check-prefix=CHECK-NO-0X %s
>>> 
>>> #if __has_feature(cxx_atomic)
>>> int has_atomic();
>>> @@ -290,3 +291,4 @@ int no_thread_local();
>>> 
>>> // CHECK-0X: has_thread_local
>>> // CHECK-NO-0X: no_thread_local
>>> +// CHECK-NO-TLS: no_thread_local
>>> 
>>> 
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>> 
>> -- Jean-Daniel
>> 
>> 
>> 
>> 
> 

-- Jean-Daniel