Re: [PATCH][RFC] Add a subset of -Warray-bounds warnings to C/C++ front ends

["Richard Guenther" <richard dot guenther at gmail dot com>]

On Fri, Apr 4, 2008 at 1:07 AM, Simon Baldwin <simonb@google.com> wrote:
> Attached below is a modest patch to provide a subset of the -Warray-bounds
>  warnings from tree-vrp.c in the C and C++ front ends.  This permits the
>  compiler to warn about egregious array bounds violations in unoptimized
>  compilations or compilations that may use -fno-tree-vrp.  At present, array
>  bounds checking is only done on optimized compilations.
>
>  A side effect of copying these warnings up into the language frontends is
>  that warnings are now printed even if the array access is in dead or
>  inaccessible code.
>
>  The current array bounds tests are modified to account for this new checking,
>  and additionally there are two new tests for warnings from -O0 compilations,
>  one for C and one for C++.
>
>  Bootstrapped, and regression tested on i686 Linux for gcc and g++.
>
>  Thoughts?  Okay for trunk?

I think it is a good thing to move these to the frontends.  Did you test
the warning on some real-world C and C++ code?  I expect some
"false" positives from deliberately partial dead code coming from
template instantiation or constant propagation from function arguments.

Thanks,
Richard.