Re: [PATCH v2] abg-reader.cc: track WIP types by pointer not name

[Dodji Seketeli <dodji@seketeli.org>]

Hello,

Giuliano Procida <gprocida@google.com> a écrit:

> When reading ABI XML files, the reader needs to construct types
> progressively as any type may depend on other types and even on
> itself. Such work-in-progress types are tracked explicitly.

Right.

Though I looked at this in details and I think this whole WIP tracking
is useless now, in the abixml reader so we might as well get rid of it
altogether.

It was used back in the old days because there was no type
de-duplication in abixml so the volume of types seen by the abixml
reader could be really huge some times.  So delaying type
canonicalization had a big impact, potentially.  So canonicalizing for a
WIP struct or function type was delayed until all the abixml file is
read.  Now in the code, all structs and function types are delayed
anyway, irrespective of their WIP-ness.  And we received no complaints
of slowness from the abixml reader.

So really, I am going to just dump the support for tracking WIP types in
the abixml reader altogether.  I am nervous about doing the same from
the DWARF reader, though, as we can see *many* more types from DWARF
because of all the duplication inherent to how the DWARF is generated at
the moment.

So I think this patch, altough valid, won't be necessary as the WIP
types tracking is going away.

>
> The storage used for this is a map from (external, qualified) type
> name to a count of how many times the type (name) has been seen.
>
> However, function type names are invariably stored as "void ()" as
> they are incomplete at the point they are added to the map. When the
> reader later attempts to remove the marking they have their proper,
> different names. In short, the code doesn't do what it's supposed to.
>

Right, I agree.  This WIP thing wasdesigned before the support for
function types was added.  And yes, the string representation of a
function types changes during its WIP life-cycle so clearly using that
representation to designate it is problematic.

So really, let's just dump the support for WIP type tracking from the
abixml reader.

I'll send a patch for that right away.

Thanks!

[...]

Cheers,

-- 
		Dodji