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From: Richard Henderson <rth@redhat.com>
To: John David Anglin <dave@hiauly1.hia.nrc.ca>
Cc: gcc@gcc.gnu.org
Subject: Re: Help! DW function pointer encoding for PA
Date: Thu, 21 Feb 2002 00:52:00 -0000	[thread overview]
Message-ID: <20020221002010.C18952@redhat.com> (raw)
In-Reply-To: <200202210734.g1L7YGvu020317@hiauly1.hia.nrc.ca>; from dave@hiauly1.hia.nrc.ca on Thu, Feb 21, 2002 at 02:34:16AM -0500

On Thu, Feb 21, 2002 at 02:34:16AM -0500, John David Anglin wrote:
> When I munge the address in ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX to make it
> look like a plabel, then the FDE search fails.

] @findex ASM_PREFERRED_EH_DATA_FORMAT
] @item ASM_PREFERRED_EH_DATA_FORMAT(@var{code}, @var{global})
] This macro chooses the encoding of pointers embedded in the exception
] handling sections.  If at all possible, this should be defined such
] that the exception handling section will not require dynamic relocations,
] and so may be read-only.
] 
] @var{code} is 0 for data, 1 for code labels, 2 for function pointers.
] @var{global} is true if the symbol may be affected by dynamic relocations.
] The macro should return a combination of the @code{DW_EH_PE_*} defines
] as found in @file{dwarf2.h}.

Note CODE==1 vs CODE==2.  You should be able to distinguish your
two cases based on this.  If absolutely necessary, pass type information
from ASM_PREFERRED_EH_DATA_FORMAT to ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX
via bits >= 0x100, ie bits that won't appear in the output file.

Note that ia64 has the same sort of function descriptor vs FDE
code label sorts of issues.


r~

  reply	other threads:[~2002-02-21  8:20 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-02-20 23:48 John David Anglin
2002-02-21  0:52 ` Richard Henderson [this message]
2002-02-21 11:33   ` John David Anglin
     [not found] <no.id>
2002-02-21 13:31 ` John David Anglin
2002-02-21 19:28   ` David Edelsohn

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