[cfe-dev] AddressSanitizer with MSVC linker errors

[Szymon Gatner]

That works, thanks!


2013/9/20 Rui Ueyama <ruiu at google.com>

> You could pass extra command line options via "LINK" environment variable.
> That might help?
>
>
> On Fri, Sep 20, 2013 at 1:25 PM, Reid Kleckner <rnk at google.com> wrote:
>
>> TL;DR, add clang_rt.asan-i386.lib to the list of libraries you link and
>> use the static, release CRT (/MT).
>>
>> Thanks for trying it!
>>
>> The problem is that you have to link the AddressSanitizer runtime library
>> to resolve those symbols.  It's distributed as a static library called
>> clang_rt.asan-i386.lib and added to the linker search path by the VS
>> integration.
>>
>> However, MSBuild invokes the link.exe tool directly, so there isn't an
>> opportunity for clang to inject the ASan RTL onto the link line like we do
>> on Unix.  We would inject it into .drectve at compile time, but you
>> actually need to use a *different* asan RTL depending on whether you are
>> building a DLL or an exe.  At compile time, we're just making .obj files,
>> and there's no flag that can tell us if we're building objs for a DLL.
>>
>> Speaking of which, if you are making a DLL,
>> use clang_rt.asan_dll_thunk-i386.lib.  =/
>>
>> You also have to use the static, release CRT to avoid symbol conflicts
>> between the asan RT and the CRT, because in essence they are both trying to
>> provide malloc, and coexisting can be tricky.
>>
>> I recommend wrapping up these options in a separate "ASan" configuration
>> parallel to Debug/Release, which we showed in the demo.
>>
>> Timur knows more, he's been working on asan in particular.
>>
>>
>> On Fri, Sep 20, 2013 at 12:27 PM, Szymon Gatner <szymon.gatner at gmail.com>wrote:
>>
>>> Hi,
>>>
>>> I just downloaded Windows / MSVC Clang installer. Integration with
>>> VC++2012 went fine and I am able to build executables with LLVM toolchain
>>> (YEY!) but after adding "-fsanitize=address" I am getting:
>>>
>>> 1>main.obj : error LNK2019: unresolved external symbol
>>> ___asan_report_store4 referenced in function _main
>>> 1>main.obj : error LNK2019: unresolved external symbol
>>> ___asan_report_load4 referenced in function _main
>>> 1>main.obj : error LNK2019: unresolved external symbol
>>> ___asan_report_load1 referenced in function _main
>>> 1>main.obj : error LNK2019: unresolved external symbol ___asan_init_v3
>>> referenced in function _asan.module_ctor
>>>
>>> I did see Chandler using it in his talk on GN2013 so I assume I am doing
>>> something wrong.
>>>
>>> Since this is my first post on this list I also want to thank all you
>>> guys for this awesome compiler. I recently have of pleasure using it on OS
>>> X (tho XCode sucks) and it would be just the best thing if I could also
>>> switch to Cland on Windows. Thanks again!
>>>
>>> Regards,
>>> Szymon Gatner
>>>
>>> _______________________________________________
>>> 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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