This is the mail archive of the
gdb@sources.redhat.com
mailing list for the GDB project.
question on gdbarch_skip_prologue()
- From: David Mosberger <davidm at napali dot hpl dot hp dot com>
- To: gdb at sources dot redhat dot com
- Cc: davidm at hpl dot hp dot com
- Date: Wed, 06 Mar 2002 22:28:04 -0800
- Subject: question on gdbarch_skip_prologue()
- Reply-to: davidm at hpl dot hp dot com
Hello,
I'm exploring the idea of changing the ia64 backend of gdb to use
unwind information instead of code-reading. While looking into this,
I started to wonder how gdbarch_skip_prologue() should be implemented.
Some backends simply return the PC that was passed into the routine,
i.e., they always assume a zero-size prologue. I'm tempted to do the
same because I worry that with optimized code, the very notion of a
prologue becomes quite fuzzy. For example, a prologue might contain a
branch and, if so, there may not even be a single PC that corresponds
to the end of the prologue.
Are there any downsides to gdbarch_skip_prologue() always returning
the original PC? Since the unwind info is accurate no matter what the
PC is, there are no problems with tracking the contents of preserved
(callee-saved) registers, but I'm wondering whether I'm missing
anything else.
Thanks,
--david