[cfe-commits] r162937 - in /cfe/trunk: include/clang/Parse/Parser.h lib/Lex/PPMacroExpansion.cpp lib/Parse/ParseExpr.cpp test/SemaCXX/libstdcxx_is_pod_hack.cpp

[Douglas Gregor]

On Nov 23, 2012, at 2:02 PM, Andy Gibbs <andyg1001 at hotmail.co.uk> wrote:

> On Thursday, August 30, 2012 9:04 PM, Douglas Gregor committed:
>> Author: dgregor
>> Date: Thu Aug 30 15:04:43 2012
>> New Revision: 162937
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=162937&view=rev
>> Log:
>> Extend the "__is_pod" hack, which demotes various type trait keywords
>> (__is_pod, __is_signed, etc.) to normal identifiers if they are
>> encountered in certain places in the grammar where we know that prior
>> versions of libstdc++ or libc++ use them, to still allow the use of
>> these keywords as type traits. Fixes <rdar://problem/9836262> and PR10184.
>> 
>> Modified:
>>   cfe/trunk/include/clang/Parse/Parser.h
>>   cfe/trunk/lib/Lex/PPMacroExpansion.cpp
>>   cfe/trunk/lib/Parse/ParseExpr.cpp
>>   cfe/trunk/test/SemaCXX/libstdcxx_is_pod_hack.cpp
>> 
>> [...snip...]
>> 
>> Modified: cfe/trunk/lib/Lex/PPMacroExpansion.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/PPMacroExpansion.cpp?rev=162937&r1=162936&r2=162937&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/Lex/PPMacroExpansion.cpp (original)
>> +++ cfe/trunk/lib/Lex/PPMacroExpansion.cpp Thu Aug 30 15:04:43 2012
>> @@ -719,22 +719,12 @@
>>            // "struct __is_empty" parsing hack hasn't been needed in this
>>            // translation unit. If it has, __is_empty reverts to a normal
>>            // identifier and __has_feature(is_empty) evaluates false.
>> -           .Case("is_empty",
>> -                 LangOpts.CPlusPlus &&
>> -                 PP.getIdentifierInfo("__is_empty")->getTokenID()
>> -                                                            != tok::identifier)
>> +           .Case("is_empty", LangOpts.CPlusPlus)
> 
> I know this is dredging something up from the distant past, but should the comment re the parsing hack also be removed like it has with the __is_pod change below?  Reviewing the code in PPMacroExpansion, I noted that __has_feature(is_empty) does not behave as the comment would imply.  I wondered whether this was a regression that had crept in at some point?
> 
> With your agreement, I'll remove the comment as obsolete.

Yes, please go ahead and remove the obsolete comment!

	- Doug


> Thanks
> Andy
> 
>>           .Case("is_enum", LangOpts.CPlusPlus)
>>           .Case("is_final", LangOpts.CPlusPlus)
>>           .Case("is_literal", LangOpts.CPlusPlus)
>>           .Case("is_standard_layout", LangOpts.CPlusPlus)
>> -           // __is_pod is available only if the horrible
>> -           // "struct __is_pod" parsing hack hasn't been needed in this
>> -           // translation unit. If it has, __is_pod reverts to a normal
>> -           // identifier and __has_feature(is_pod) evaluates false.
>> -           .Case("is_pod",
>> -                 LangOpts.CPlusPlus &&
>> -                 PP.getIdentifierInfo("__is_pod")->getTokenID()
>> -                                                            != tok::identifier)
>> +           .Case("is_pod", LangOpts.CPlusPlus)
>>           .Case("is_polymorphic", LangOpts.CPlusPlus)
>>           .Case("is_trivial", LangOpts.CPlusPlus)
>>           .Case("is_trivially_assignable", LangOpts.CPlusPlus)
>