building gcc-2.8.1-980206 on alpha-unknown-linux-gnu

[Alexandre Oliva]

I wrote:

>> I've had a bit of trouble building gcc-2.8.1-980206 with egcs-980205's
>> libstdc++ and libg++-2.8.1-980201.  The problem occurs when it tries
>> to build gperf in libg++: the virtual table definition for class
>> exception is missing.

H J Lu writes:

> DON'T USE gcc 2.8 on linux/alpha. As far as I know, it is broken.
> egcs is fine. To make gcc 2.8 working, you need many changes in
> config/alpha and config scripts from egcs. But I have no idea how
> they will interact with gcc 2.8.

I was just going to run the tests for gcc 2.8.1 on alpha (which we
should do to get it ever working), when I found trouble because of the
vtable incompatibility.

No matter gcc is completely broken for that target or not, the build
process of libstdc++ and libg++ must *not* override the vtable format
determined by either gcc or by the user that is building it.  Doing
this is asking for linking errors like the one I noticed.

If a platform requires a specific vtable formats to work, it is the
default vtable format in g++ that must be changed, not the one
libstdc++ and libg++ use.

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:aoliva@acm.org
http://www.dcc.unicamp.br/~oliva
Universidade Estadual de Campinas, SP, Brasil