[PATCH/gdbtk] Update stackwin gdb api usage

[Roland Schwingel <roland at onevision dot com>]

Hi...

Here is a new patch from my side for insight. It adresses 2 issues.

The small one first:
In the tcl code of the stackwindow there is an instance variable 
maxwidth which is calculated but never used somewhere. My patch dares to 
remove it.

The bigger one:
I am frequently seeing output in insight on windows 64 bit:

(Internal error: pc 0x0 in read in psymtab, but not in symtab.)

Especially when debugging objectiveC code but can also see in sometimes 
when debugging plain c. This is triggered by stack unwinding (showing 
stack window in insight). I tracked it down to 2 problems. One of it is 
in insight itself and fixed with this patch.

The C code of insight dealing with the backtrace generation was made 
somewhere in 2001 and remainded largely unchanged since then. It was 
initially "inspired" by the code directly in gdb. GDB has changed since 
then in that area. I updated insight's C code for generating the 
backtrace for the tcl part to match again gdb's code in stack.c. I could 
remove a bigger bunch of insight's private code in that area and replace 
it directly with a call to find_frame_funname() of gdb itself. I also 
removed some dead code here.

From what I could see now insight no longer genarates this error 
message directly. I could still trigger it in some situations by just 
issuing a "bt" from either insight's console or from within native gdb. 
I have to dive into that. But with this patch insight itself should be 
clean now in this regard.

I also updated copyright informations in the affected files.

Changelog:
2012-04-02  Roland Schwingel  <roland.schwingel@onevision.com>

	* generic/gdbtk-stack.c: Updated copyright informations.
	include "stack.h" and "solib.h" (when needed).
	(gdb_stack): Some reformatting.
	(get_frame_name): Updated usage of gdb api for
        backtrace generation. Some reformatting. Removed
	dead code. Also handle frame type ARCH_FRAME now.
	* library/stackwin.it[bh]: Remove dead instance
	variable maxwidth. Updated copyright informations.

A general question:
The direction of stack dump in insight is opposite to when issueing a 
backtrace inside gdb itself. Is this on purpose? Wouldn't it be nicer 
when insight's stack window would show the stack in the same order?

Any comments? Is this ok?

Roland

Attachment: stackwin.patch
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