[Buildroot] [PATCH v2 2/6] package/llvm: install target binary/debug tools

[Romain Naour]

Hi Matt,

Le 21/11/2018 à 04:12, Matthew Weber a écrit :
> On Tue, Nov 20, 2018 at 4:37 PM Romain Naour <romain.naour at gmail.com> wrote:
>>
>> Hi Matt,
>>
>> Le 19/11/2018 à 14:04, Matthew Weber a écrit :
>>> Romain,
>>>
>>> On Mon, Nov 19, 2018 at 2:10 AM Romain Naour <romain.naour at gmail.com> wrote:
>>>>
>>>> Hi Matt,
>>>>
>>>> Le lun. 19 nov. 2018 à 02:48, Matthew Weber <matthew.weber at rockwellcollins.com> a écrit :
>>>>>
>>>>> Romain,
>>>>>
>>>>> On Sun, Nov 18, 2018 at 1:14 PM Romain Naour <romain.naour at smile.fr> wrote:
>>>>>>
>>>>>> Hi Matt,
>>>>>>
>>>>>> Le 17/11/2018 à 04:56, Matt Weber a écrit :
>>>>>>> The compiler-rt fuzzer and address sanitizer tools require additional
>>>>>>> LLVM binary tools installed to allow stack trace decoding actively during
>>>>>>> executable analysis.
>>>>>>>
>>>>>>> https://github.com/google/sanitizers/wiki/AddressSanitizerCallStack
>>>>>>>
>>>>>>> Signed-off-by: Matthew Weber <matthew.weber at rockwellcollins.com>
>>>>>>> Reviewed-by: Romain Naour <romain.naour at smile.fr>
>>>>>>
>>>>>> For some reason I get an error while building llvm package tools.
>>>>>>
>>>>>> x86_64-linux-g++: WARNING: unsafe header/library path used in cross-compilation:
>>>>>> '-I/usr/include/libxml2'
>>>>>>
>>>>>> Can you have a look?
>>>>>
>>>>> I went back and checked my logs on the clang compiler-rt run-test
>>>>> build for that warning and didn't find it.  I then checked and my
>>>>> config and it has the unsafe header/library as error.  Was your build
>>>>> test just applying my patches and doing an explicit 'make llvm'?
>>>>
>>>>
>>>> Indeed,
>>>> Some tools use libxml2, so you have to add target libxml2 package as build dependency.
>>>>
>>>
>>> Would you mind sharing your verbose output and equivalent of cmake
>>> config guess/status?
>>>
>>
>> I need to rebuild from scratch since I've fixed the build locally.
>> I'll restart a new one next week-end.
>>
> 
> Something like the following added to package/llvm/llvm.mk?  (Still
> haven't see this on my end.  I messed with my host system a bit to get
> libxml2 support and headers in place, no luck.)
> 
> # LLVM requires libxml2
> HOST_LLVM_CONF_OPTS += \
>        -DLIBXML2_LIBRARIES=$(HOST_DIR)/lib \
>        -DLIBXML2_INCLUDE_DIR=$(HOST_DIR)/include/libxml2
> HOST_LLVM_DEPENDENCIES += host-libxml2
> LLVM_CONF_OPTS += \
>        -DLIBXML2_LIBRARIES=$(STAGING_DIR)/usr/lib \
>        -DLIBXML2_INCLUDE_DIR=$(STAGING_DIR)/usr/include/libxml2
> LLVM_DEPENDENCIES += libxml2

I reproduced the issue: https://pastebin.com/s8PZvuGt

The CMakeCache.txt content seems interesting:

//Path to a file.
LIBXML2_INCLUDE_DIR:PATH=LIBXML2_INCLUDE_DIR-NOTFOUND

//Path to a library.
LIBXML2_LIBRARY:FILEPATH=LIBXML2_LIBRARY-NOTFOUND

//Path to a program.
LIBXML2_XMLLINT_EXECUTABLE:FILEPATH=/usr/bin/xmllint

//Use libxml2 if available. Can be ON, OFF, or FORCE_ON
LLVM_ENABLE_LIBXML2:STRING=ON

LLVM_ENABLE_LIBXML2 allow to define LLVM_LIBXML2_ENABLED

$ grep -r LLVM_LIBXML2_ENABLED in the build directory:
cmake/modules/CMakeFiles/LLVMConfig.cmake:set(LLVM_LIBXML2_ENABLED 0)
NATIVE/cmake/modules/CMakeFiles/LLVMConfig.cmake:set(LLVM_LIBXML2_ENABLED 1)
NATIVE/lib/cmake/llvm/LLVMConfig.cmake:set(LLVM_LIBXML2_ENABLED 1)
NATIVE/include/llvm/Config/config.h:#define LLVM_LIBXML2_ENABLED 1
lib/cmake/llvm/LLVMConfig.cmake:set(LLVM_LIBXML2_ENABLED 0)
include/llvm/Config/config.h:/* #undef LLVM_LIBXML2_ENABLED */

It seems that llvm try to build something for the host (NATIVE) while building
target llvm package. Sadly it use the cross-compiler to build them and that is
why we hit the paranoid wrapper.

> 
> The interesting thing is that it looks like just a windows manifest
> manager source file uses the libxml2.  Unsure of it's role....

Then we can just add -DLLVM_ENABLE_LIBXML2=OFF for host-llvm and llvm.

Best regards,
Romain

> 
> 
> Matt
>