[LLVMdev] [PATCH] Removing -fsanitize-address-zero-base-shadow

[Greg Fitzgerald]

Sounds good.  Thanks for the heads up.

-Greg

On Tue, Jan 14, 2014 at 11:46 PM, Kostya Serebryany <kcc at google.com> wrote:
>
>
>
> On Wed, Jan 15, 2014 at 11:38 AM, Evgeniy Stepanov
> <eugeni.stepanov at gmail.com> wrote:
>>
>> Hi,
>>
>> we plan to remove -fsanitize-address-zero-base-shadow command line
>> flag from clang, and disable zero-base shadow support on all platforms
>> where it is not the default behavior.
>>
>> - It is completely unused, as far as we know. And completely undocumented,
>> too.
>
> Not completely undocumented:
> https://code.google.com/p/address-sanitizer/wiki/ZeroBasedShadow
> Still, I think we can nuke this code now. (== LGTM)
>
>
>>
>> - It is ABI-incompatible with non-zero-base shadow, which means all
>> objects in a process must be built with the same setting. Failing to
>> do so results in a segmentation fault at runtime.
>> - It introduces a backward dependency of compiler-rt on user code,
>> which is uncommon and complicates testing.
>>
>> For the reference, attaching patches to cfe, llvm and compiler-rt that
>> remove the flag and all support for it in the ASan instrumentation
>> pass and runtime library.
>
>
>
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