[cfe-dev] RTTI on Windows

[Klaim - Joël Lamotte]

Hi,

I just read http://llvm.org/bugs/show_bug.cgi?id=18332
and http://llvm.org/bugs/show_bug.cgi?id=17403 after finding the following
issue (first attempt at using the toolchain for windows).
Am I correct that the following problem is also due to the lack of RTTI
support?
It looks like I can't use std::array.

Program (compiled with LLVM-VS2013):

    #include <array>
    int main()
    {
        std::array<int,42> my_array;
    }

Output:

------ Build started: Project: Test_ClangToolchain, Configuration: Debug
Win32 ------
1>clang-cl.exe : warning : argument unused during compilation: '/ZI'
1>clang-cl.exe : warning : argument unused during compilation: '/Gm'
1>clang-cl.exe : warning : argument unused during compilation: '/EHsc'
1>clang-cl.exe : warning : argument unused during compilation: '/GS'
1>clang-cl.exe : warning : argument unused during compilation: '/fp:precise'
1>clang-cl.exe : warning : argument unused during compilation:
'/FdDebug\vc120.pdb'
1>clang-cl.exe : warning : argument unused during compilation: '/Gd'
1>main.cpp(4,23): warning : unused variable 'my_array' [-Wunused-variable]
1>      std::array<int,42> my_array;
1>                         ^
1>CL : error : cannot mangle RTTI descriptors for type 'codecvt' yet
1>CL : error : cannot mangle the name of type 'codecvt' into RTTI
descriptors yet
1>CL : error : cannot mangle RTTI descriptors for type 'codecvt_base' yet
1>CL : error : cannot mangle the name of type 'codecvt_base' into RTTI
descriptors yet
1>CL : error : cannot mangle RTTI descriptors for type 'facet' yet
1>CL : error : cannot mangle the name of type 'facet' into RTTI descriptors
yet
1>CL : error : cannot mangle RTTI descriptors for type '_Facet_base' yet
1>CL : error : cannot mangle the name of type '_Facet_base' into RTTI
descriptors yet
1>  1 warning and 8 errors generated.
Build has been canceled.
Build Summary
-------------
00:02.032 - Failed  - Debug Win32 -
Test_ClangToolchain\Test_ClangToolchain.vcxproj

Total build time: 00:02.032

========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped, Completed
at 2014/02/02 01:33:41 ==========



On Wed, Jan 8, 2014 at 8:57 PM, David Majnemer <david.majnemer at gmail.com>wrote:

> Hello Daniel,
>
> I am currently working on an implementation of RTTI for MSVC
> compatibility.  As it stands, there is a lot left to do.
>
> If you'd like to help me, I think a good first step that has to happen is
> to achieve an understanding of what the different flags mean in the Base
> Class Descriptors.
>
> I'm available on IRC if you have any specific questions.
>
> --
> David Majnemer
>
>
> On Wed, Jan 8, 2014 at 11:20 AM, Daniel Olivier <dan_olivier at hotmail.com>wrote:
>
>> Hello,
>>
>> I've recently started using Clang on Windows (VC10), and quickly ran into
>> this limitation.
>> I have started to try to split the code paths into Itanium-specific and
>> Microsoft-specific methods, but lack a bit of experience with Clang to
>> really get this off the ground.
>>
>> Undoubtedly, I'm making a serious mistake, but it seems to me that this
>> is a serious limitation (in the Windows world, where it is not at all
>> common practice to have access to all the source code for all the
>> dependencies). I see this as a problem stemming from the failure to link
>> with existing libraries (precompiled with MS-style compilers, such as the
>> CRT), and therefore an ABI issue.
>>
>> I would like to help to try to produce a solution. I've seen the code and
>> realize this is a large (huge?) undertaking. Is it even thinkable (for
>> some reason that escapes now me)?
>>
>> The question is: who has any specific knowledge of this part of the code
>> (RTTI and virtual table construction)? Among those people, are there any
>> who could spare some time to comment on this undertaking and perhaps
>> provide a bit of guidance? Has anyone already tried to do this, or has it
>> slated?
>>
>> Thanks,
>> Dan
>>
>>
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>
>>
>
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>
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