Add support for suppressions in LeakCheck

[euspectre]

Original issue 12 created by euspectre on 2013-04-12T07:37:28.000Z:

There are situations where LeakCheck may output many false positives (see http://code.google.com/p/kedr/wiki/Known_Issues) which are currently too difficult to avoid.

Perhaps the means to suppress some kinds of errors could be useful here. The idea is similar to what Valgrind already uses, esp. for glibc, GTK+ and so on: http://valgrind.org/docs/manual/manual-core.html#manual-core.suppress

I guess, we don't need exactly those complex Valdrind-style suppressions, something that would allow identify the events to be supressed by their type and call stack would probably do.

Something like this:

ALLOC func1 * func2 func3

That would mean, "suppress reporting of memory leaks with the call stack that contains the following sequence of items: func1 called from somewhere (*), called from func2, which was in turn called from func3".

The call stack does not have to be fully defined, it a part of it matches, that would do.

Another example:

FREE func_bar

That would mean, "suppress reporting of unallocated frees if such events happened in func_bar(), including the functions called from it, etc."

The suppression information could be passed to to LeakCheck via debugfs, for example.