Re: [SH][PATCH] Disable ABI frame sniffer

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 09 Nov 2005 17:12:15 +0000
> From: Andrew STUBBS <andrew.stubbs@st.com>
> 
> It is useful to disable this sniffer because it has an irritating habit 
> of causing (non-fatal) errors when it runs out of frames. Specifically 
> it often says 'Previous frame identical to this frame (corrupt stack?)'.
> 
> This message is worrying if you do not know what it means, but it is 
> normally easily ignored. Unfortunately, the problem is more serious when 
> used in conjunction with 'thread apply' as the first error kills the 
> output from the rest of the threads. This command is used by some GUIs 
> to populate their displays.

I think this explanation should be in the manual, because it explains
very clearly when this command is useful.

> +  add_setshow_boolean_cmd ("abi-sniffer", class_obscure,
> +                           &backtrace_abi_sniffer, "\
> +Set whether backtraces should use the ABI where there is no debug info.", "\
> +Show whether backtraces should use the ABI where there is no debug info.", "\
> +Normally there is debug information from which to construct a backtrace\n\
> +but sometimes is is not available (e.g. in assembly code). In this case the\n\
> +ABI sniffer can attempt to construct a backtrace. It is disabled by default\n\
> +because it can cause inconvenient errors. Note that it does not disable the\n\
> +Dwarf debug information sniffer.",

These strings should be in _(), to allow for their translation to
other languages.  See the other examples of using
add_setshow_boolean_cmd in GDB's sources.

> Index: src/gdb/doc/gdb.texinfo
> ===================================================================
> --- src.orig/gdb/doc/gdb.texinfo	2005-11-01 11:43:29.000000000 +0000
> +++ src/gdb/doc/gdb.texinfo	2005-11-01 12:56:00.000000000 +0000
> @@ -14790,8 +14790,21 @@ commands:
>  @item regs
>  @kindex regs@r{, Super-H}
>  Show the values of all Super-H registers.
> +
> +@item set backtrace abi-sniffer
> +@kindex set backtrace abi-sniffer
> +This command enables or disables the SH ABI-based frame sniffer. This
> +`sniffer' attempts to find the frames of a backtrace when there is no
> +debug information (specifically CFI) to do the job properly. Sniffing
> +frames is problematic so it is often best to switch this @samp{off}. It
> +is @samp{on} by default.
> +
> +@item show backtrace abi-sniffer
> +@kindex show backtrace abi-sniffer
> +Show whether the abi-sniffer is enabled, or not.

This part is fine with me, provided that you fix the following
gotchas:

 . Make sure there are 2 blanks after a period that ends a sentence.

 . Use ``sniffer'' instead of `sniffer' (two quote characters).

 . Replace the "Sniffing is problematic..." sentence with text similar
   to the one you included in your message that explains when this
   command would be useful.

>  @end table
>  
> +
>  @node WinCE

Please don't add this gratuitous whitespace.