[LLVMdev] compiler-rt with MSVC 2013

[Aaron Ballman]

On Thu, Oct 23, 2014 at 2:24 PM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
> I don't think this is the right approach.
>
> Currently we intentionally define malloc etc without changing the
> names and (when stuff works ok) the linker just links all the mem
> allocator calls with calls to our RTL.  This is kind of a link-time
> interception.

How could that work in the presence of also having the MSVC CRT
libraries linked in? When the linker finds the duplicate definition of
any of those functions, it will produce that link error. You can use
/FORCE:multiple to work around that, but then any usage of free()
within compiler-rt is liable to find the asan definition.

> I'm not 100% sure off the top of my head but I think __asan_init is
> explicitly called from the CRT init code later than calloc gets
> called() from CRT.  To handle everything correctly, calloc() must be
> "statically" intercepted before __asan_init is called from the CRT
> (hence before "dynamic" interceptors are set up).
>
> Can you please compare what happens in your build configuration compared to:
> $ cmake -GNinja -DLLVM_ENABLE_ASSERTIONS=ON -DCMAKE_BUILD_TYPE=Release
> -DLLVM_TARGETS_TO_BUILD=X86 .. && ninja
> instead?

Do I need something special to support ninja?

E:\llvm\compiler-rt-ninja>cmake -GNinja -DLLVM_ENABLE_ASSERTIONS=ON -DCMAKE_BUIL
D_TYPE=Release -DLLVM_TARGETS_TO_BUILD=X86 ..\compiler-rt && ninja
CMake Error: CMake was unable to find a build program corresponding to "Ninja".
 CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build t
ool.
CMake Error: Error required internal CMake variable not set, cmake may be not be
 built correctly.
Missing variable is:
CMAKE_C_COMPILER_ENV_VAR
CMake Error: Error required internal CMake variable not set, cmake may be not be
 built correctly.
Missing variable is:
CMAKE_C_COMPILER
CMake Error: Could not find cmake module file: E:/llvm/compiler-rt-ninja/CMakeFi
les/2.8.12.2/CMakeCCompiler.cmake
CMake Error: Error required internal CMake variable not set, cmake may be not be
 built correctly.
Missing variable is:
CMAKE_CXX_COMPILER_ENV_VAR
CMake Error: Error required internal CMake variable not set, cmake may be not be
 built correctly.
Missing variable is:
CMAKE_CXX_COMPILER
CMake Error: Could not find cmake module file: E:/llvm/compiler-rt-ninja/CMakeFi
les/2.8.12.2/CMakeCXXCompiler.cmake
-- Configuring incomplete, errors occurred!

~Aaron

>
> 2014-10-23 11:17 GMT-07:00 Aaron Ballman <aaron at aaronballman.com>:
>> I think this issue is that we were not using the INTERCEPTOR macros to
>> define these functions. The following patch seems to work for me to
>> get the build linking again, however, I cannot test -- when I run
>> check-asan, I get:
>>
>> 2>  lit.py: lit.common.cfg:59: fatal: Invalid llvm_tools_dir config
>> attribute: 'E:/llvm/2013/$(Configuration)/bin'
>>
>> ~Aaron
>>
>> On Thu, Oct 23, 2014 at 1:20 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
>>> On Thu, Oct 23, 2014 at 1:18 PM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
>>>> http://llvm.org/bugs/show_bug.cgi?id=21241
>>>> ?
>>>
>>> Yuuuup, looks like that's it. :-) I'll see if I can debug and fix.
>>>
>>> Thanks!
>>>
>>> ~Aaron
>>>
>>>>
>>>> 2014-10-23 10:18 GMT-07:00 Aaron Ballman <aaron at aaronballman.com>:
>>>>> On Thu, Oct 23, 2014 at 1:15 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
>>>>>> On Thu, Oct 23, 2014 at 1:13 PM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
>>>>>>> Yes it is.
>>>>>>> Are you doing a Debug or Release build?
>>>>>>> Using ninja?
>>>>>>
>>>>>> Release build, cmake + MSVC (not using ninja).
>>>>>>
>>>>>> Perhaps I have it configured stupidly; I have it as an out-of-tree folder, did:
>>>>>>
>>>>>> E:\llvm\crt_build>cmake -DLLVM_CONFIG_PATH=E:\llvm\2013\Debug\bin -G
>>>>>> "Visual Studio 12" ..\compiler-rt
>>>>>
>>>>> Sorry, that should read:
>>>>>
>>>>> E:\llvm\crt_build>cmake
>>>>> -DLLVM_CONFIG_PATH=E:\llvm\2013\Debug\bin\llvm-config.exe -G "Visual
>>>>> Studio 12" ..\compiler-rt
>>>>>
>>>>> ~Aaron
>>>>>>
>>>>>> Opened up the solution, hit Build All.
>>>>>>
>>>>>> ~Aaron
>>>>>>
>>>>>>>
>>>>>>> 2014-10-23 9:51 GMT-07:00 Aaron Ballman <aaron at aaronballman.com>:
>>>>>>>> Hello! I'm wondering whether compiler-rt is expected to be buildable
>>>>>>>> with MSVC 2013. I am currently getting:
>>>>>>>>
>>>>>>>> Error 49 error LNK2005: _free already defined in asan_malloc_win.obj
>>>>>>>> E:\llvm\crt_build\lib\asan\MSVCRT.lib(MSVCR120.dll)
>>>>>>>>
>>>>>>>> Which seems to be the only issue (aside from ~50 warnings, which I'll
>>>>>>>> happily work on cleaning up). I get this when I build the ALL_BUILD
>>>>>>>> project in the solution from cmake.
>>>>>>>>
>>>>>>>> Thanks!
>>>>>>>>
>>>>>>>> ~Aaron
>>>>>>>> _______________________________________________
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