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Re: Recent removal of the 'aux' field in tree_common
- From: Geoff Keating <geoffk at geoffk dot org>
- To: Diego Novillo <dnovillo at redhat dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: 28 Feb 2002 08:52:26 -0800
- Subject: Re: Recent removal of the 'aux' field in tree_common
- References: <20020228160600.GA5835@tornado.toronto.redhat.com>
Diego Novillo <firstname.lastname@example.org> writes:
> Is the idea to remove the aux field for good? If so, I'd like to
> discuss ways of mapping mechanisms so that we can associate other
> data structures to a tree.
> Having the aux field is convenient because it's quick and simple.
One problem with the 'aux' field is that it is incompatible with PCH.
For PCH, you really want every pointer in every structure to have one
and only one type. In particular, you don't want to have void *
The idea behind the PCH code is that it runs through every data
structure in the compiler, and writes them to disk. This means that
it needs to know where every pointer is and the size of every object.
It also has to read all the data structures from disk, which means it
needs to know how to allocate every kind of data structure, and it
needs to know how to de-allocate any structure that is replaced.
- Geoffrey Keating <email@example.com> <firstname.lastname@example.org>