[Dwarf-discuss] DWARF Issue 050808.2&body=Re: <ahref=http://dwarf.freestandards.org/ShowIssue.php

[Daniel Berlin]

On Thu, 2006-02-23 at 19:40 -0800, Michael Eager wrote:
> Daniel Berlin wrote:
> > On Thu, 2006-02-23 at 18:55 -0800, Michael Eager wrote:
> > 
> >>Wu Zhou wrote:
> >>
> >>>Hello, committee members
> >>>
> >>>Now that DWARF-3 had been published for a while, can I have the pleasure 
> >>>to re-open this deferred issue?
> >>>
> >>>I don't see any action I can do from the net.  So I am asking here.
> >>>
> >>>Regards
> >>>- Wu Zhou
> >>
> >>http://dwarf.freestandards.org/ShowIssue.php?issue=050808.2&type=closed
> >>
> >>We will consider revisions to the DWARF standard starting mid-year.
> >>
> >>The proposal is somewhat vague.  I'm personally unclear
> >>why there is a need for an new TAG.  Saying Stabs does something
> >>one way so DWARF should do the same is not persuasive.
> >>
> >>Is there a reason why using DW_TAG_entry_point doesn't work?
> > 
> > 
> > DW_TAG_entry_point was very specifically pointed out to *not* be the
> > same as what he is looking for, IIRC.
> 
> As I indicated, the proposal is vague.  Also short.
> 
> The mention of DW_TAG_entry_point along with your name suggests, in an
> unclear fashion, that you believed it to be adequate.  Perhaps this is
> inaccurate, but that's at least how I read the proposal.
Well, it would be, but we'd need a flag.



> 
> >>In general, proposals which have been implemented are preferred.
> > 
> > We specifically put off adding it to GCC to get resolution *first*, so
> > this is kinda a downer.  Why create the chance that someone will do this
> > again a different way, when this is a simple issue that could be
> > resolved once, first?
> > 
> > This is not something we need heavy implementation experience to determine 
> > whether it is useful or not.  
> > But I guess for now, Wu, DW_TAG_GNU_entry_point or whatever should be added.
> 
> Again, this is a general principle.  Unless there is a clear
> proposal (which this is not) then the preference is for some
> demonstration that the proposed change actually addresses
> the issue.
> 
> Again, I read the very few lines of the proposal and I don't
> find it clear.  Perhaps making a clear and complete proposal
> would be a more productive way to get a resolution.

Okay, well, let me simply edit the "proposal" (which i agree is not a
proposal)

Most C compiler assume the main function to be "main".  Other 
languages might have different names, or even allow it to have 
any name.  If we have an entry to tell what is the main function 
in a program, it will let the debugger to present this to users 
in an intelligent way.  Another debug-info format stabs could 
support this with N_MAIN stab type.


Proposal:

I propose we modify the definition of the DW_TAG_entry_point tag definition to state 
that it is also usable for specifying the main entry point to a program, 
not just fortran alternate entry points.

In order to determine which of the DW_TAG_entry_point is the single main entry point to the program,
 a flag attribute DW_AT_is_main(or something suitably named) should be added to the allowed attributes for DW_TAG_entry_point.

Alternatively, we could define it as the entry_point with DW_CC_program calling convention, and delete the text that says
"The DW_CC_program value is intended to support Fortran main programs. It is not intended as a way of finding the entry address for the program."



>