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Re: Future of libio vtable compatibility
On Mon, Jun 18, 2018 at 3:08 PM, Florian Weimer <fw@deneb.enyo.de> wrote:
> * Zack Weinberg:
>>
>> This is not quite the same thing as vtable compatibility, but based on
>> having had to read a bunch of the relevant code for the bits/types/
>> work, I suspect that programs that require the "old" FILE struct have
>> been broken for some time.
>
> Do you mean source-level brokenness, or something that affects
> compiled binaries?
Something that affects compiled binaries. Basically, there were so
many casts back and forth among the _IO_FILE_* variations that I could
not persuade myself that the code was strict-aliasing safe nor that it
actually guaranteed "old" FILEs would never get passed to functions
that expected "new" FILEs. And because we have no tests for any of
those code paths, we only know that that stuff still compiles, not
that it still works.
zw