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Re: [PATCH tracing/kprobes v2 1/5] tracing/kprobes: Rename special variables syntax
- From: Frederic Weisbecker <fweisbec at gmail dot com>
- To: Masami Hiramatsu <mhiramat at redhat dot com>
- Cc: Steven Rostedt <rostedt at goodmis dot org>, Ingo Molnar <mingo at elte dot hu>, lkml <linux-kernel at vger dot kernel dot org>, systemtap <systemtap at sources dot redhat dot com>, DLE <dle-develop at lists dot sourceforge dot net>, Thomas Gleixner <tglx at linutronix dot de>, Arnaldo Carvalho de Melo <acme at redhat dot com>, Mike Galbraith <efault at gmx dot de>, Paul Mackerras <paulus at samba dot org>, Peter Zijlstra <a dot p dot zijlstra at chello dot nl>, Christoph Hellwig <hch at infradead dot org>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Jim Keniston <jkenisto at us dot ibm dot com>, "Frank Ch. Eigler" <fche at redhat dot com>
- Date: Mon, 5 Oct 2009 21:26:11 +0200
- Subject: Re: [PATCH tracing/kprobes v2 1/5] tracing/kprobes: Rename special variables syntax
- References: <20091002214834.30906.86502.stgit@dhcp-100-2-132.bos.redhat.com> <20091002214842.30906.49220.stgit@dhcp-100-2-132.bos.redhat.com> <20091003015444.GE4828@nowhere> <4AC830F0.2010003@redhat.com> <4ACA25D5.10703@redhat.com>
On Mon, Oct 05, 2009 at 12:59:01PM -0400, Masami Hiramatsu wrote:
> As far as I can see in arch/*/include/asm/ptrace.h, all registers start with
> alphabets :-). So, I'd like to suggest renaming sp-vars to '_sp-vars'.
>
> Then, we will have;
> - $local-vars
There is a risk of bash collision.
> - @global-symbol
We could use global-symbol as is. Shadowing between global
and local vars could be dealt with scope resolution:
function:var
file:var
file:line:var
And throw errors while submitting a shadowed var name, crying until
the user defines the scope, only if needed of course (if there are
no shadowing detected, we can submit a naked variable name).
> - regs
That can conflict with variable names
> - _sp-vars
That too.
> - +|-Offs(ARG)
You mean for arg numbers?
So we would have +1 for argument 1?
arg(1) looks more easy to remember and to understand, no?
Thanks.