[cfe-dev] New operator and some others don't have matching symbol names between clang and visual studio?

Thu Dec 26 02:53:53 PST 2013

Makes sense to me. I think most people picking up clang for the first time
would assume that to be the default behavior. Thanks a lot for the help.

On Thu, Dec 26, 2013 at 4:35 PM, David Majnemer <david.majnemer at gmail.com>wrote:

> You are correct that "-cxx-abi microsoft" with an appropriate win32 triple
> is what I would consider ABI compatible.  However, reliance on that cc1
> flag is ill-advised.  I (and to my knowledge all others involved in the
> MSVC ABI effort) want the triple to implicitly control which ABI is
> selected while removing the -cxx-abi flag altogether.
>
>
> On Wed, Dec 25, 2013 at 11:39 PM, Astron B <boldaster at gmail.com> wrote:
>
>> Hey David,
>>
>> Thanks a lot for the quick response. I had assumed this mode was already
>> enabled since while using clang++.exe it said the target is i686-pc-win32
>> rather than i686-pc-mingw. When calling the clang driver cc1 directly is
>> "-cxx-abi" "microsoft" the argument that enables this mode? Thanks.
>>
>>
>> On Thu, Dec 26, 2013 at 2:28 PM, David Majnemer <david.majnemer at gmail.com
>> > wrote:
>>
>>> clang++.exe defaults to the mingw ABI.  It seems you want to use
>>> clang-cl.exe, it uses the MSVC ABI.  Note that clang-cl.exe's argument
>>> parsing is compatible with MSVC's cl.exe while clang++.exe is compatible
>>> with gcc.
>>>
>>>
>>> On Wed, Dec 25, 2013 at 10:03 PM, Astron B <boldaster at gmail.com> wrote:
>>>
>>>> Hey,
>>>>
>>>> I have an issue while trying to link some clang compiled code. When I
>>>> compile my test dll with clang I get a new operator like this:
>>>>
>>>> __Znwj
>>>>
>>>> I guess this is conformant with GCC's naming.
>>>>
>>>> But when compiling with visual studio the new operator is:
>>>>
>>>> Searching libraries
>>>>     Searching C:\Program Files (x86)\Microsoft Visual Studio
>>>> 11.0\VC\LIB\MSVCRTD.lib:
>>>>       Found __purecall
>>>>         Referenced in ConsoleApplication2.obj
>>>>         Loaded MSVCRTD.lib(MSVCR110D.dll)
>>>>       Found "void * __cdecl operator new(unsigned int)" (??2 at YAPAXI@Z)
>>>>         Referenced in ConsoleApplication2.obj
>>>>         Loaded MSVCRTD.lib(MSVCR110D.dll)
>>>>       Found "void __cdecl operator delete(void *)" (??3 at YAXPAX@Z)
>>>>         Referenced in ConsoleApplication2.obj
>>>>         Loaded MSVCRTD.lib(MSVCR110D.dll)
>>>>
>>>> I also noticed that with Clang I get a symbol for pure call catches
>>>> called:
>>>> ___cxa_pure_virtual
>>>>
>>>> I assume the __purecall above is the visual studio version.
>>>>
>>>> When I try to link the clang compiled object file using link.exe I get
>>>> unresolved symbol errors because of this.
>>>>
>>>> F:\LLVM-fresh\vs11\bin\Debug>clang++ -c testdll.cpp -o testdll.o -v
>>>> clang version 3.5 (trunk)
>>>> Target: i686-pc-win32
>>>> Thread model: posix
>>>>  "F:\LLVM-fresh\vs11\bin\Debug\clang++.exe" -cc1 -triple i686-pc-win32
>>>> -emit-obj
>>>>  -mrelax-all -disable-free -main-file-name testdll.cpp
>>>> -mrelocation-model static
>>>>  -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases
>>>> -target-cpu
>>>> pentium4 -v -coverage-file
>>>> "F:\\LLVM-fresh\\vs11\\bin\\Debug\\testdll.o" -resour
>>>> ce-dir "F:\\LLVM-fresh\\vs11\\bin\\Debug\\..\\lib\\clang\\3.5"
>>>> -internal-isystem
>>>>  "F:\\LLVM-fresh\\vs11\\bin\\Debug\\..\\lib\\clang\\3.5\\include"
>>>> -internal-isys
>>>> tem "C:\\Program Files (x86)\\Microsoft Visual Studio
>>>> 10.0\\VC\\INCLUDE" -intern
>>>> al-isystem "C:\\Program Files (x86)\\Microsoft Visual Studio
>>>> 10.0\\VC\\ATLMFC\\I
>>>> NCLUDE" -internal-isystem "C:\\Program Files (x86)\\Microsoft
>>>> SDKs\\Windows\\v7.
>>>> 0A\\include" -std=c++11 -fdeprecated-macro -fdebug-compilation-dir
>>>> "F:\\LLVM-fre
>>>> sh\\vs11\\bin\\Debug" -ferror-limit 19 -fmessage-length 80
>>>> -mstackrealign -fms-e
>>>> xtensions -fms-compatibility -fmsc-version=1700
>>>> -fdelayed-template-parsing -fobj
>>>> c-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option
>>>> -fcolor-di
>>>> agnostics -vectorize-slp -o testdll.o -x c++ testdll.cpp
>>>> clang -cc1 version 3.5 based upon LLVM 3.5svn default target
>>>> i686-pc-win32
>>>> #include "..." search starts here:
>>>> #include <...> search starts here:
>>>>  F:\LLVM-fresh\vs11\bin\Debug\..\lib\clang\3.5\include
>>>>  C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE
>>>>  C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\ATLMFC\INCLUDE
>>>>  C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\include
>>>> End of search list.
>>>>
>>>> F:\LLVM-fresh\vs11\bin\Debug>nm testdll.o
>>>> 00000000 t .text
>>>> 00000000 t .text
>>>> 00000001 a @feat.00
>>>> 00000000 T __ZN7testOneC2Ev
>>>>          U __Znwj
>>>> 00000000 T _whatever
>>>>
>>>> F:\LLVM-fresh\vs11\bin\Debug>
>>>>
>>>>
>>>> C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin>link /DLL
>>>> /NOENTRY te
>>>> stdll.o /VERBOSE
>>>> Microsoft (R) Incremental Linker Version 11.00.50727.1
>>>> Copyright (C) Microsoft Corporation.  All rights reserved.
>>>>
>>>>
>>>> Starting pass 1
>>>>
>>>> Searching libraries
>>>>
>>>> Finished searching libraries
>>>>
>>>> Finished pass 1
>>>>
>>>> testdll.o : error LNK2019: unresolved external symbol __Znwj referenced
>>>> in funct
>>>> ion _whatever
>>>> testdll.dll : fatal error LNK1120: 1 unresolved externals
>>>>
>>>>
>>>>
>>>> How can I get this to link? Thanks.
>>>>
>>>> _______________________________________________
>>>> cfe-dev mailing list
>>>> cfe-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>
>>>>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20131226/dabfd3e1/attachment.html>