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To: Daniel Jacobowitz <drow@mvista.com>
Cc: gdb-patches@sources.redhat.com
Subject: Re: [ppc64-linux]: skip linkage functions
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	<20030606000328.GA26538@nevyn.them.org> <vt27k7zybbw.fsf@zenia.home>
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	<20030606214003.GA11393@nevyn.them.org>
From: Jim Blandy <jimb@redhat.com>
Date: Fri, 06 Jun 2003 22:47:00 -0000
In-Reply-To: <20030606214003.GA11393@nevyn.them.org>
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Daniel Jacobowitz <drow@mvista.com> writes:
> On Fri, Jun 06, 2003 at 03:31:58PM -0500, Jim Blandy wrote:
> > Daniel Jacobowitz <drow@mvista.com> writes:
> > > What blows up if we don't recognize the trampolines though?
> > 
> > On the PPC64, 'next' blows up.
> 
> Oh, I hit this problem on another platform recently.  And I had to do a
> similar hack for trampolines.
> 
> It seems that there shold be a simpler solution than trying to parse
> the trampoline...

Well, the only relevant piece of machine state is the PC.  From there
you can either look at the code (trampoline parsing), or look at
meta-information associated with the address (DW_AT_trampoline).  That
exhausts the possibilities, doesn't it?

A simpler meta-information approach might be to insert some new sort
of symbol (STT_GNU_TRAMPOLINE?) whose value was the start address of
the trampoline, and whose name was the name of the function the
trampoline called.  Then in_solib_call_trampoline would just check for
an STT_GNU_TRAMPOLINE symbol, and skip_trampoline_code would return
the value of the STT_FUNC symbol of the same name.