[scan-build] [Patch] Compiler call interceptor for Linux

[Aleksei Sidorin]

Hello Laszlo,

Thanks, that is interesting.
I read this in Bear description:
"The concept behind Bear is to exec the original build command and 
intercept the |exec| calls of the build tool. To achive that Bear uses 
the |LD_PRELOAD| or |DYLD_INSERT_LIBRARIES| mechanisms provided by the 
dynamic linker."

I tried to escape this approach because it can face some problems with 
emulator-based build systems. For example, it can cause conflicts of 
build and interceptor architectures and there may be incorrect paths 
after chroot. If you are familiar with this tool, can you check it for 
correct work with chroot build environments (like osc: 
http://en.opensuse.org/openSUSE:Build_Service_Tutorial)? As I understand 
from description, it may have some problems with emulator-based build 
systems.



15.05.2014 12:11, Laszlo Nagy пишет:
> Interesting approach you have showed Aleksei. I had a similar problem, 
> but approached it differently... I wrote a program which intercept the 
> compiler calls and generate a compilation database. (you can generate 
> it from cmake files) That tool is called bear 
> <https://github.com/rizsotto/Bear>, and it works on linux/FreeBSD/OS X 
> as well... And with the rewrite of scan-build wanted to extend the 
> current functionality to use the compilation database (beside to work 
> with the current environment based approach)... At this moment I still 
> work on the ccc-analyzer implementation in python... Алексей Климов 
> and Sylvestre Ledru in the frame of a GSoC also wanted to rewrite the 
> scan-build part.
>
>
> On Tue, May 13, 2014 at 6:01 PM, Jordan Rose <jordan_rose at apple.com 
> <mailto:jordan_rose at apple.com>> wrote:
>
>     [+cfe-commits again, -cfe-dev]
>
>     Interested yes, but unfortunately not all of the people involved
>     in the analyzer are using Linux systems. (I'm on OS X.) I've CC'd
>     a few other recent contributors to the analyzer, but I can't
>     remember if they are familiar with and have access to Linux
>     systems either. (Laszlo in particular is attempting to rewrite
>     scan-build in Python, for more uniformity with the rest of LLVM,
>     so this is the sort of thing he'd want to stay up-to-date about.)
>
>     Sorry for not being so responsive here,
>     Jordan
>
>
>     On May 13, 2014, at 8:47 , Aleksei Sidorin <a.sidorin at samsung.com
>     <mailto:a.sidorin at samsung.com>> wrote:
>
>     > Hello again,
>     >
>     > I sent a message to cfe-commits mailing list, but nobody
>     answered. This task is listed in open projects. Is anybody
>     interested in this interceptor?
>     >
>     > Link to review: http://reviews.llvm.org/D3608
>     >
>     > 29.04.2014 09:38, Aleksei Sidorin:
>     >> Hello,
>     >>
>     >> This patch enables interception of compiler calls without
>     replacement of environment variables. It uses strace (v.4.8) to
>     compute root directory of processes (in case of chroot), working
>     directory, process name and its environment variables and tries to
>     guess some header directories. This approach works well with
>     Android and some build systems like OBS (local build with osc
>     client) and GBS (checked on Tizen). This behaviour can be enabled
>     with --use-interceptor option. If this option is not specified,
>     old behaviour is used (this patch was made to not break it).
>     >>
>     >> Interceptor uses process pool to analyze multiple files at a
>     time. Pool size can be specified with NUM_PROCESSES environment
>     variable. Default pool size is a number of processors.
>     >>
>     >> If we have a trace of build (that may be created with `strace
>     -f -v -s 1000000 -o $trace_file_name -e
>     trace=vfork,fork,clone,execve,chdir,chroot -e signal=
>     $build_cmd`), it can be passed via TRACE_FILE environment
>     variable. This will not launch parallel build (analysis only). If
>     option is not specified, temporary pipe is used, analyzer and
>     compiler are executed in parallel.
>     >>
>     >> -additional-arg option was also added to pass additional
>     parameters to analyzer. Sometimes scan-build cannot determine all
>     required parameters if some custom toolchain is used.
>     >>
>     >> Interceptor was tested on Ubuntu 12.04 and 14.04 with strace
>     4.8. Strace v.4.6 is known to have some issues with interception
>     of gcc.
>     >>
>     >
>     >
>     > --
>     > Best regards,
>     > Aleksei Sidorin
>     > Software Engineer,
>     > IMSWL-IMCG, SRR, Samsung Electronics
>     >
>
>


-- 
Best regards,
Aleksei Sidorin
Software Engineer,
IMSWL-IMCG, SRR, Samsung Electronics

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