[LLVMdev] AddressSanitizer run-time in tools/clang/runtime/compiler-rt

[Daniel Dunbar]

Quick answers, I'm on txgiving break this week and not doing any real
work, but I will be doing more compiler-rt work when I get back
(initially focused at getting profile libs to come from compiler-rt on
Linux et al).

On Wed, Nov 16, 2011 at 9:24 PM, Kostya Serebryany <kcc at google.com> wrote:
> Hi Daniel,
> Chris suggested to talk to you about committing the AddressSanitizer (asan)
> run-time into the llvm tree (llvm-project/compiler-rt).
> Questions:
> - What is the preferred name for the directory? (asan? libasan?
> address_sanitizer? AdressSanitizer?)

I don't care. lib/asan seems perfectly reasonable to me, with a README
explaining what the module is for.

> - Should the asan run-time use cmake, or just make, or what? The build is a
> bit tricky, especially for tests. We currently use make.

The only build system I care about for compiler-rt is the one in make.
It's quite a crazy set up, although there is a reason for it to be as
complicated as it is. I can help (and/or) do the asan integration into
the compiler-rt make build.

> - How would you suggest to do the code review?
>    The code of the run-time is ~5
> KLOC. http://code.google.com/p/address-sanitizer/source/browse/#svn%2Ftrunk%2Fasan
>    The Apple-specific part may make some Apple experts cry (or maybe not).
>    The code uses google's coding style, which is similar, but not equivalent
> to the LLVM's one. We check it using cpplint before commits.

I personally would like to see it be in LLVM style, but the rest of
compiler-rt isn't really that way, so I don't think this is a blocker.

Unless anyone objects, I think we should just bring the code in as is
so that ASAN works, and if people want to do more thorough review that
can happen post commit.

>    LLVM license is used.
>    The tests are ~2.5 KLOC; most of the tests require the clang compiler
> with -faddress-sanitizer switch.
>    If possible, I'd prefer not to review the patch in a usual way (too big),
> but instead have the comments to the files
> in http://code.google.com/p/address-sanitizer/source/browse/#svn%2Ftrunk%2Fasan
>    Or, alternatively, commit everything as is and then iterate over
> individual files.
> - The run-time library uses a couple of third_party files (BSD license) to
> parse process mapping.
>   W/o these files asan will work, but will not produce symbolizable traces.
>   Can we include these files as as in a separate directory? (They may be
> useful for other tools as well)

Let's try to include the bits with extra licenses in subdirectories of
lib/asan. If someone wants to reuse them later we can find a different
way to factor things, I don't see a reason to worry about it now.

>   http://code.google.com/p/address-sanitizer/source/browse/trunk/asan/sysinfo.cc
> - Yet another piece of third-party code (mit license) is used for
> Apple-specific work (function overriding). Same question as above apply.
>
>  http://code.google.com/p/address-sanitizer/source/browse/trunk/asan/mach_override.c
> - test-specific: can I rely on gtest being installed? (fresh version is
> required).

Compiler-rt doesn't currently have a very good test set up. You'll
probably have to find a way to shoehorn this in for your own testing
initially, but we can try and work out a way to integrate it more
properly...

 - Daniel

> Thanks,
> --kcc
>
>