[commit] Fix Xtensa-specific bug in MI command

[commit] Fix Xtensa-specific bug in MI command

[Maxim Grigoriev]

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Fix Xtensa-specific bug in MI command -data-list-changed-registers.



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2011-03-08  Maxim Grigoriev  <maxim2405@gmail.com>

	* xtensa-tdep.c (xtensa_register_reggroup_p): Count in all registers
	while executing MI command -data-list-changed-registers.

Index: gdb/xtensa-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/xtensa-tdep.c,v
retrieving revision 1.49
diff -u -r1.49 xtensa-tdep.c
--- gdb/xtensa-tdep.c	9 Mar 2011 02:25:12 -0000	1.49
+++ gdb/xtensa-tdep.c	9 Mar 2011 02:51:35 -0000
@@ -813,6 +813,11 @@
   xtensa_register_group_t rg = reg->group;
   int cp_number;
 
+  if (group == save_reggroup)
+    /* Every single register should be included into the list of registers
+       to be watched for changes while using -data-list-changed-registers.  */
+    return 1;
+
   /* First, skip registers that are not visible to this target
      (unknown and unmapped registers when not using ISS).  */
 
@@ -828,13 +833,11 @@
     return rg & xtRegisterGroupFloat;
   if (group == general_reggroup)
     return rg & xtRegisterGroupGeneral;
-  if (group == float_reggroup)
-    return rg & xtRegisterGroupFloat;
   if (group == system_reggroup)
     return rg & xtRegisterGroupState;
   if (group == vector_reggroup || group == xtensa_vectra_reggroup)
     return rg & xtRegisterGroupVectra;
-  if (group == save_reggroup || group == restore_reggroup)
+  if (group == restore_reggroup)
     return (regnum < gdbarch_num_regs (gdbarch)
 	    && (reg->flags & SAVE_REST_FLAGS) == SAVE_REST_VALID);
   if ((cp_number = xtensa_coprocessor_register_group (group)) >= 0)

Re: [commit] Fix Xtensa-specific bug in MI command

[Joel Brobecker]

> Fix Xtensa-specific bug in MI command -data-list-changed-registers.

A small request: If you could give more details with your patches
about what you are fixing.  For the previous ones, there wasn't
much to add, just extending support for new features.  But for this
one, it would have been helpful to know what type of bug it was.
For instance, a transcript showing the issue can be useful to
other people hitting the problem, and doing an internet search.

-- 
Joel

Re: [commit] Fix Xtensa-specific bug in MI command

[Maxim Grigoriev]

On 03/08/2011 07:51 PM, Joel Brobecker wrote:
>> Fix Xtensa-specific bug in MI command -data-list-changed-registers.
>>      
> A small request: If you could give more details with your patches
> about what you are fixing.  For the previous ones, there wasn't
> much to add, just extending support for new features.  But for this
> one, it would have been helpful to know what type of bug it was.
> For instance, a transcript showing the issue can be useful to
> other people hitting the problem, and doing an internet search.
>
>    
Eclipse CDT uses this MI command to get a list of changed
registers compared to the previous register file state saved before.
It happens, when Eclipse user opens a register display window.
After each new event in the debugging session, such as "step",
"next" ( which lead to executing some instruction(s) on the target ),
updated registers are high-lighted in that display window.

MI command  -data-list-changed-registers uses generic hook

      gdbarch_register_reggroup_p ()

to analyse updates to the register file.

Registers from standard GDB group "save_reggroup" have
to be always a part of this analysis.

It's been missing on Xtensa. That's why changed registers
did not always display  properly in the Eclipse register
display window.

Thanks for your notes and suggestions,
-- Maxim Grigoriev

Tensilica, Inc.
Santa Clara, CA
408-566-1770