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Date: Sun, 18 Oct 2009 03:56:00 -0000
From: Michael Snyder <msnyder@vmware.com>
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To: Hui Zhu <teawater@gmail.com>
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Subject: Re: [RFA] record.c - save some memory in record log.
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Hui Zhu wrote:
> Thanks Michael, This patch is very cool.
> 
> +struct record_reg_entry
> +{
> +  unsigned short num;
> +  unsigned short len;
> +  union
> +  {
> +    gdb_byte *ptr;
> +    gdb_byte buf[2 * sizeof (gdb_byte *)];
> 
> Why this part use "2 * sizeof (gdb_byte *)"?

Oh, no strong reason.  I just noticed that mem_entry is larger
than reg_entry, and since it is used in a union, that space is
otherwise going to waste.

I do not assume that a target general register is the same size
as a host pointer -- only that the larger we make this buf, the
less likely that we have to use malloc.

> 
> +    rec->u.reg.u.ptr = (gdb_byte *) xmalloc (MAX_REGISTER_SIZE);
> I suggest change MAX_REGISTER_SIZE to rec->u.reg.len.

Ah, good idea, thanks.  I'll make that change.

Any other comments?