[LLVMdev] Building sanitizers for Android

[Greg Fitzgerald]

> This is a public interface. But ASan runtime (and test-suite) strongly depends on
> the instrumentation pass in Clang.

How do you feel about adding a runtime init check of a version number
defined by asan_interface.h?

-Greg


On Tue, Apr 22, 2014 at 11:16 AM, Alexey Samsonov <samsonov at google.com> wrote:
>
> On Tue, Apr 22, 2014 at 10:43 AM, Greg Fitzgerald <garious at gmail.com> wrote:
>>
>> Sorry for the slow replies.  I'm out on vacation this week.
>>
>>
>> Alexey wrote:
>> > If you want to test the sanitizer runtiume library "during development",
>> > you should verify that it works with the Clang at hand.
>>
>> I want to test an implementation of libraries, not that clang links a
>> library in its install directory.  We only need one clang test for the
>> latter (not 100) and that test already exists in the clang test suite.
>
>
> No. The test in the clang test suite only calls "clang -fsanitize=address
> -###" and matches
> the command Clang will call linker with. It doesn't verify that the link
> will succeed, or that
> the resulting binary would run and produce expected output.
>
>>
>>
>>
>> > Sanitizer runtime and the compiler are tightly
>> > coupled, why would you want to test the former in isolation?
>>
>> They aren't that tightly-coupled though.  There's an interface and an
>> implementation.  That interface rarely changes relative to the number
>> of changes to the implementation.
>>
>>
>> https://github.com/llvm-mirror/compiler-rt/commits/master/include/sanitizer
>
>
> This is a public interface. But ASan runtime (and test-suite) strongly
> depends on the instrumentation
> pass in Clang. The latter can define hidden experimental flags we are
> testing. Instrumentation pass
> and compiler-rt library depend on each other. There were _several_ changes
> in instrumentation pass
> last week, most of which required a corresponding change in compiler-rt:
>
> https://github.com/llvm-mirror/llvm/commits/master/lib/Transforms/Instrumentation/AddressSanitizer.cpp
>
>>
>>
>> https://github.com/llvm-mirror/compiler-rt/commits/master/lib
>
>
>>
>>
>>
>>
>> > Modifying Clang driver for testing-only purposes, especially for testing
>> > in a non-default
>> > configuration doesn't sound good to me.
>>
>> Agreed and that's not what's happening.  The optional part is adding a
>> -L flag to the invocation of clang within the compiler-rt test suite.
>> If using the monolithic build, those flags are not added and clang
>> finds the libs via its hardcoded '-L' flag.
>>
>>
>> Yury wrote:
>> > It's not that easy. Some tests require passing environment variables
>>
>> As Evgeniy mentioned, it's a short enough list of variables that you
>> can whitelist them.  LD_PRELOAD, LD_LIBRARY_PATH, ASAN_OPTIONS, etc.
>>
>>
>> Evgeniy wrote:
>> > Greg, do you copy binaries to the device on %clang or on %run?
>>
>> %run.  Can you point me to a case where you needed to override %clang for
>> that?
>>
>> Thanks,
>> Greg
>>
>> On Mon, Apr 21, 2014 at 12:54 AM, Evgeniy Stepanov <eugenis at google.com>
>> wrote:
>> > Both %run and my symlink approach add certain (yet undocumented)
>> > requirements on the tests, but they should be 100% robust if those
>> > requirements are followed.
>> > Greg, do you copy binaries to the device on %clang or on %run? The
>> > latter would miss shared libraries that are not executed directly.
>> > Environment can be recreated on the device, my script attempts to do
>> > it (for several whitelisted variables).
>> > We don't preserve ulimit setting, I modified one or two tests to not
>> > rely on that.
>> >
>> > I don't mind switching to a combined approach - copy to device on
>> > %clang, and replace symlink hacks with %run.
>> >
>> >
>> >
>> > On Mon, Apr 21, 2014 at 9:09 AM, Yury Gribov <y.gribov at samsung.com>
>> > wrote:
>> >>> We considered adding "%run" to all binary invocations,
>> >>> but dropped this idea. I don't remember the details, but IIRC %run is
>> >>> just not general enough.
>> >>
>> >>
>> >> IMHO this is where simplicity of lit approach starts to fail -
>> >> important
>> >> information (environment variables, dependent shared libs, expected
>> >> test
>> >> status, etc.) is buried inside arbitrarily complex runstrings.
>> >>
>> >> -Y
>
>
>
>
> --
> Alexey Samsonov, Mountain View, CA