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Re: [PATCH, vtv update] Add documentation for --enable-vtable-verify configure option...
- From: Caroline Tice <cmtice at google dot com>
- To: Diego Novillo <dnovillo at google dot com>
- Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, Benjamin Kosnik <bkoz at redhat dot com>
- Date: Fri, 6 Sep 2013 08:28:02 -0700
- Subject: Re: [PATCH, vtv update] Add documentation for --enable-vtable-verify configure option...
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- References: <CABtf2+Tjd7bmk_--inhVS7NSiwrXtcbMDBVvOnODTByoVev0EA at mail dot gmail dot com> <Pine dot LNX dot 4 dot 64 dot 1308082209420 dot 13573 at digraph dot polyomino dot org dot uk> <CABtf2+S_3qVp=5NZPsa6kDpoiFLjD5te78CGo8_tyKZAaf6NyQ at mail dot gmail dot com> <5229DCF1 dot 4000307 at google dot com>
On Fri, Sep 6, 2013 at 6:47 AM, Diego Novillo <firstname.lastname@example.org> wrote:
> On 2013-08-28 17:15 , Caroline Tice wrote:
>> # Least ordering for dependencies mean linking w/o libstdc++ for as
>> # long as the development of libvtv does not absolutely require it.
>> Index: gcc/doc/install.texi
>> --- gcc/doc/install.texi (revision 202060)
>> +++ gcc/doc/install.texi (working copy)
>> @@ -1032,6 +1032,16 @@ and for cross builds configured with @op
>> More documentation about multiarch can be found at
>> +@item --enable-vtable-verify
>> +Specify whether to enable or disable the vtable verification feature.
>> +Enabling this feature causes libstdc++ to be built with its virtual calls
>> +in verifiable mode. This means that, when linked with libvtv, every
>> +virtual call in libstdc++ will verify the vtable pointer through which
>> +call will be made before actually making the call. If not linked with
>> +the verifier will call stub functions (in libstdc++ itself) and do
>> +If vtable verification is disabled, then libstdc++ is not built with its
>> +virutal calls in verifiable mode at all.
> Could you clarify in the docs whether --enable-vtable-verify is the default
> behaviour or not?
It will not be the default, but yes I will clarify.
> Why would I need --disable-vtv, if I can use --disable-vtable-verify?
--disable-vtable-verify prevents libstdc++ from being build with
verification turned on, but the libvtv library will still be built.
--disable-libvtv prevents the libvtv library from being built.
Obviously I need to add a comment like this to the documentation, so I
> OK with those changes.