[llvm] r201679 - Disable override and final C++ keyword in gcc 4.6.

[Logan Chien]

Hi Gordon,

I have tried to use cmake as well.  I can build and test without problem as
well.  These are the commands which I am using:

$ cmake ../llvm -DCMAKE_CXX_FLAGS=-std=c++0x
-DLLVM_FORCE_USE_OLD_TOOLCHAIN=1
$ make -j4
$ make check-all

Sincerely,
Logan


On Fri, Feb 21, 2014 at 10:20 PM, Logan Chien <tzuhsiang.chien at gmail.com>wrote:

> Hi Gordon,
>
> I am using autoconf.  I can build without problem with following commands:
>
> $ export CXXFLAGS=-std=c++0x
> $ ./configure --enable-optimized --disable-compiler-version-checks
> $ make -j4
> $ make check-all
>
> The revision which I am using are LLVM/r201841, clang/r201849, and
> compiler-rt/r201845.
>
> The gcc version I am using is:
>
> $ gcc --version
> gcc-4.6.real (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
>
> Sincerely,
> Logan
>
>
> On Fri, Feb 21, 2014 at 2:45 AM, Gordon Keiser <gkeiser at arxan.com> wrote:
>
>> I pulled down trunk on Tuesday night, and it errors in CMake on linux if
>> GCC < 4.7, so I'm not really sure what purpose this serves.
>>
>>
>>
>> -Gordon
>>
>>
>>
>> *From:* llvm-commits-bounces at cs.uiuc.edu [mailto:
>> llvm-commits-bounces at cs.uiuc.edu] *On Behalf Of *Logan Chien
>> *Sent:* Wednesday, February 19, 2014 12:11 PM
>> *To:* Aaron Ballman
>> *Cc:* llvm-commits
>> *Subject:* Re: [llvm] r201679 - Disable override and final C++ keyword
>> in gcc 4.6.
>>
>>
>>
>> Hi Aaron,
>>
>> I know that GCC 4.7 is the minimum support compiler.  However, since the
>> change is limited to the compiler compatibility header (there are even some
>> checks for GCC 3.1 in this header) and this change fixes the build and
>> passes all test cases, I feel it is acceptable in this case.
>>
>> Although I know the code base might be incompatible with GCC 4.6 in the
>> near future, I wish to keep the backward compatibility as long as possible
>> given that only some simple change to compiler compatibility header is
>> required.  I agree that it won't make sense to stick with old syntax or
>> prohibit the usage of new language feature just for the backward
>> compatibility of the unsupported GCC 4.6.
>>
>> Sincerely,
>>
>> Logan
>>
>>
>>
>> On Wed, Feb 19, 2014 at 11:27 PM, Aaron Ballman <aaron at aaronballman.com>
>> wrote:
>>
>> Since our min supported compiler version is 4.7 (as of llvm 3.4), I
>> don't believe this commit really makes sense. Since we're trying to
>> make the switch to using C++11 functionality, I don't think we want to
>> add support for older compilers which will fail in other ways.
>>
>> ~Aaron
>>
>>
>> On Wed, Feb 19, 2014 at 10:04 AM, Logan Chien <tzuhsiang.chien at gmail.com>
>> wrote:
>> > Author: logan
>> > Date: Wed Feb 19 09:04:29 2014
>> > New Revision: 201679
>> >
>> > URL: http://llvm.org/viewvc/llvm-project?rev=201679&view=rev
>> > Log:
>> > Disable override and final C++ keyword in gcc 4.6.
>> >
>> > According to http://gcc.gnu.org/projects/cxx0x.html,
>> > override and final keyword was added in gcc 4.7.  Thus,
>> > we should not use these keywords in gcc 4.6 even when
>> > __GXX_EXPERIMENTAL_CXX0X__ is available.
>> >
>> > Modified:
>> >     llvm/trunk/include/llvm/Support/Compiler.h
>> >
>> > Modified: llvm/trunk/include/llvm/Support/Compiler.h
>> > URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Compiler.h?rev=201679&r1=201678&r2=201679&view=diff
>> >
>> ==============================================================================
>> > --- llvm/trunk/include/llvm/Support/Compiler.h (original)
>> > +++ llvm/trunk/include/llvm/Support/Compiler.h Wed Feb 19 09:04:29 2014
>> > @@ -152,7 +152,8 @@
>> >  /// LLVM_FINAL - Expands to 'final' if the compiler supports it.
>> >  /// Use to mark classes or virtual methods as final.
>> >  #if __has_feature(cxx_override_control) || \
>> > -    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1700)
>> > +    (defined(__GXX_EXPERIMENTAL_CXX0X__) && __GNUC_PREREQ(4, 7)) || \
>> > +    LLVM_MSC_PREREQ(1700)
>> >  #define LLVM_FINAL final
>> >  #else
>> >  #define LLVM_FINAL
>> > @@ -161,7 +162,8 @@
>> >  /// LLVM_OVERRIDE - Expands to 'override' if the compiler supports it.
>> >  /// Use to mark virtual methods as overriding a base class method.
>> >  #if __has_feature(cxx_override_control) || \
>> > -    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1700)
>> > +    (defined(__GXX_EXPERIMENTAL_CXX0X__) && __GNUC_PREREQ(4, 7)) || \
>> > +    LLVM_MSC_PREREQ(1700)
>> >  #define LLVM_OVERRIDE override
>> >  #else
>> >  #define LLVM_OVERRIDE
>> >
>> >
>> > _______________________________________________
>> > llvm-commits mailing list
>> > llvm-commits at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
>>
>>
>
>
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