Re: typeinfo nodes resolution

[Andrey Slepuhin <pooh at msu dot net>]

On 28-Jan-98 Jason Merrill wrote:
>>>>>> Andrey Slepuhin <pooh@msu.ru> writes:
> 
>> On 28-Jan-98 Jason Merrill wrote:
>>>>>>>> Andrey Slepuhin <pooh@msu.net> writes:
> 
>>>> this header. The problem is because in the second
>>>> case typeinfo nodes should be generated using ".lcomm"
>>>> assembler directive instead of ".comm", i.e. they
>>>> should not be global.
> 
>>> This is wrong.  They must be global, as they must be resolved to a single
>>> object.  The linker should not warn about such things.
> 
>> But what should I do if AIX native linker can not resolve
>> multiple instances, if they are in different shared objects?
> 
> Then I guess we have to handle AIX differently.  Currently, equality tests
> for type_info nodes just compare addresses; I guess we'll have to use the
> name on AIX.

Grr... This is bad...
Possible workarounds:
1) First check for address equality and may be for equality of hash values
   dependent on symbol names;

2) The best solution for AIX may be the following:
   a. To add a pointer to an external variable into typeinfo nodes.
      (compiler task).
   b. To generate an import list for these external variables when
      building a shared object (collect2 task).
   c. To define these variables in auto-generated C file when building
      an executable (collect2 task).
   So, pointers will be resolved during program build and will have
   equal values for equal typeinfo nodes. I don't know if it is difficult
   (or possible at all) to change typeinfo nodes structure for AIX,
   but appropriate collect2 changes can be done easy.
   
Sorry for additional troubles,
Andrey.