Re: [PATCH v6 2/2] gdb: add shadowed field in '-stack-list-locals/variables' mi commands

[Guinevere Larsen <blarsen@redhat.com>]

On 22/11/2023 09:13, Abdul Basit Ijaz wrote:
> From: "Ijaz, Abdul B" <abdul.b.ijaz@intel.com>
>
> For C/C++/Fortran languages GDB prints same name variable multiple times in
> case of variable shadowing and it is confusing for user to identify which
> variable belongs to the current scope.  So GDB now prints location information
> for shadowed variables and add 'shadowed' field also in '-stack-list-locals'
> and '-stack-list-variables' mi commands for super-block shadowed variable.
>
> Suppose we have test.c file
>
> 1:int x = 42;
> 2:  {
> 3:    int x = 99;
> 4:    int y = 52;
> 4:    x = 99; /* break here */
> 5:  }
>
> The "-stack-list-locals" and "-stack-list-variables" mi commands at the
> "break here" line gives the following output:
>
> Before the change:
>
> ~~~
> (gdb)
> -stack-list-locals 0
> ^done,locals=[name="x",name="y",name="x"]
> (gdb)
> -stack-list-locals 1
> ^done,locals=[{name="x",value="99"},{name="y",value="52"},{name="x",value="42"}]
> (gdb)
> -stack-list-locals 2
> ^done,locals=[{name="x",type="int",value="99"},{name="y",type="int",value="52"},{name="x",type="int",value="42"}]
> (gdb)
> -stack-list-variables 0
> ^done,variables=[{name="x"},{name="y"},{name="x"}]
> (gdb)
> -stack-list-variables 1
> ^done,variables=[{name="x",value="99"},{name="y",value="52"},{name="x",value="42"}]
> (gdb)
> -stack-list-variables 2
> ^done,variables=[{name="x",type="int",value="99"},{name="y",type="int",value="52"},{name="x",type="int",value="42"}]
> ~~~
>
> With this patch we obtain:
>
> ~~~
> (gdb)
> -stack-list-locals 0
> ^done,locals=[name="x",name="y",name="x"]
> (gdb)
> -stack-list-locals 1
> ^done,locals=[{name="x",value="99",file="test.c",line="4"},{name="y",value="52"},{name="x",value="42",file="test.c",line="2",shadowed="true"}]
> (gdb)
> -stack-list-locals 2
> ^done,locals=[{name="x",type="int",value="99",file="test.c",line="4"},{name="y",type="int",value="52"},{name="x",type="int",value="42",file="test.c",line="2",shadowed="true"}]
> (gdb)
> -stack-list-variables 0
> ^done,variables=[{name="x",file="test.c",line="4"},{name="y"},{name="x",file="test.c",line="2",shadowed="true"}]
> (gdb)
> -stack-list-variables 1
> ^done,variables=[{name="x",value="99",file="test.c",line="4"},{name="y",value="52"},{name="x",value="42",file="test.c",line="2",shadowed="true"}]
> (gdb)
> -stack-list-variables 2
> ^done,variables=[{name="x",type="int",value="99",file="test.c",line="4"},{name="y",type="int",value="52"},{name="x",type="int",value="42",file="test.c",line="2",shadowed="true"}]
> ~~~

I don't really know mi, but I tested this and it works without 
introducing regressions.

Tested-By: Guinevere Larsen <blarsen@redhat.com>

-- 
Cheers,
Guinevere Larsen
She/Her/Hers

> ---
>   gdb/doc/gdb.texinfo                       |  14 +++
>   gdb/mi/mi-cmd-stack.c                     |  66 +++++++++-
>   gdb/testsuite/gdb.mi/mi-var-shadowing.c   |  48 ++++++++
>   gdb/testsuite/gdb.mi/mi-var-shadowing.exp | 141 ++++++++++++++++++++++
>   4 files changed, 265 insertions(+), 4 deletions(-)
>   create mode 100644 gdb/testsuite/gdb.mi/mi-var-shadowing.c
>   create mode 100644 gdb/testsuite/gdb.mi/mi-var-shadowing.exp
>
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 6efcc5a8dc9..348844bbb8d 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -34772,6 +34772,20 @@ If the @code{--skip-unavailable} option is specified, local variables
>   and arguments that are not available are not listed.  Partially
>   available arguments and local variables are still displayed, however.
>   
> +@smallexample
> +1: int x = 3;
> +2: @{
> +3:       int x = 4; // breakpt
> +4: @}
> +(gdb) -stack-list-variables 2
> +^done,variables=[@{name="x",type="int",value="4",file="name.c",line="3"@},@{name="x",type="int",value="3",file="name.c",line="1",shadowed="true"@}]
> +@end smallexample
> +
> +A variable is shadowed when there's another variable by the same
> +name which is declared within an inner scope (decision block,
> +method, or inner class).  For such cases, its location for the
> +outermost scope is followed by @samp{shadowed} attribute.
> +
>   @subsubheading Example
>   
>   @smallexample
> diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
> index e473be7d465..21638796b63 100644
> --- a/gdb/mi/mi-cmd-stack.c
> +++ b/gdb/mi/mi-cmd-stack.c
> @@ -38,6 +38,8 @@
>   #include "gdbsupport/gdb-safe-ctype.h"
>   #include "inferior.h"
>   #include "observable.h"
> +#include "include/libiberty.h"
> +#include <unordered_set>
>   
>   enum what_to_list { locals, arguments, all };
>   
> @@ -491,7 +493,9 @@ mi_cmd_stack_list_variables (const char *command, const char *const *argv,
>   
>   static void
>   list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
> -		   enum print_values values, int skip_unavailable)
> +		   enum print_values values, int skip_unavailable,
> +		   const std::unordered_set<std::string> *shadowed_vars,
> +		   std::unordered_set<std::string> &printed_vars)
>   {
>     struct ui_out *uiout = current_uiout;
>   
> @@ -520,6 +524,18 @@ list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
>       tuple_emitter.emplace (uiout, nullptr);
>   
>     string_file stb;
> +  const char *name = arg->sym->print_name ();
> +  bool already_printed = !printed_vars.insert (name).second;
> +  printed_vars.insert (name);
> +  bool shadowed = shadowed_vars->find (name) != shadowed_vars->end ();
> +
> +  /* In case of Rust language it is possible to declare variable with
> +     same name multiple times and only latest declaration of variable
> +     is accessible.  So print only the first instance and there is no
> +     need of printing duplicates.  */
> +  if (current_language->la_language == language_rust
> +      && shadowed && already_printed)
> +    return;
>   
>     stb.puts (arg->sym->print_name ());
>     if (arg->entry_kind == print_entry_values_only)
> @@ -559,6 +575,23 @@ list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
>   	}
>         uiout->field_stream ("value", stb);
>       }
> +
> +  /* Only for C/C++/Fortran/Ada languages, in case of variables shadowing
> +     print shadowed field after the superblock variable and only location
> +     of the variables in the innerblock.  */
> +  if ((current_language->la_language == language_c
> +       || current_language->la_language == language_cplus
> +       || current_language->la_language == language_fortran
> +       || current_language->la_language == language_ada)
> +       && !(values == PRINT_NO_VALUES && what == locals)
> +       && shadowed)
> +    {
> +      const char *file_name = lbasename (arg->sym->owner.symtab->filename);
> +      uiout->field_string ("file", file_name);
> +      uiout->field_unsigned ("line", arg->sym->m_line);
> +      if (already_printed)
> +	uiout->field_string ("shadowed", "true");
> +    }
>   }
>   
>   /* Print a list of the objects for the frame FI in a certain form,
> @@ -572,9 +605,10 @@ list_args_or_locals (const frame_print_options &fp_opts,
>   		     enum what_to_list what, enum print_values values,
>   		     frame_info_ptr fi, int skip_unavailable)
>   {
> -  const struct block *block;
> +  const struct block *block, *orig_block;
>     const char *name_of_result;
>     struct ui_out *uiout = current_uiout;
> +  std::unordered_set<std::string> collected_vars, shadowed_vars, printed_vars;
>   
>     block = get_frame_block (fi, 0);
>   
> @@ -595,6 +629,26 @@ list_args_or_locals (const frame_print_options &fp_opts,
>   
>     ui_out_emit_list list_emitter (uiout, name_of_result);
>   
> +  orig_block = block;
> +  /* Stored list of shadowed variables later help in identifying them
> +     from the rest.  */
> +  while (block != nullptr)
> +    {
> +      for (struct symbol *sym : block_iterator_range (block))
> +	{
> +	  if (!sym->is_argument ())
> +	    {
> +	      const char *name = sym->print_name ();
> +	      if (!collected_vars.insert (name).second)
> +		shadowed_vars.insert (name);
> +	    }
> +	}
> +      if (block->function ())
> +	break;
> +      block = block->superblock ();
> +    }
> +
> +  block = orig_block;
>     while (block != 0)
>       {
>         for (struct symbol *sym : block_iterator_range (block))
> @@ -663,9 +717,13 @@ list_args_or_locals (const frame_print_options &fp_opts,
>   		}
>   
>   	      if (arg.entry_kind != print_entry_values_only)
> -		list_arg_or_local (&arg, what, values, skip_unavailable);
> +		list_arg_or_local (&arg, what, values,
> +				   skip_unavailable, &shadowed_vars,
> +				   printed_vars);
>   	      if (entryarg.entry_kind != print_entry_values_no)
> -		list_arg_or_local (&entryarg, what, values, skip_unavailable);
> +		list_arg_or_local (&entryarg, what, values,
> +				   skip_unavailable, &shadowed_vars,
> +				   printed_vars);
>   	    }
>   	}
>   
> diff --git a/gdb/testsuite/gdb.mi/mi-var-shadowing.c b/gdb/testsuite/gdb.mi/mi-var-shadowing.c
> new file mode 100644
> index 00000000000..f58a055c5e5
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/mi-var-shadowing.c
> @@ -0,0 +1,48 @@
> +/* Copyright (C) 2023 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +#include <stdlib.h>
> +
> +void
> +shadowing (void)
> +{
> +  int a;	/* entry bp */
> +  unsigned int val1 = 1;		/* val1-d1 */
> +  unsigned int val2 = 2;		/* val2-d1 */
> +  a = 101;  /* bp for locals 1 */
> +  {
> +    unsigned int val2 = 3;		/* val2-d2 */
> +    unsigned int val3 = 4;		/* val3-d1 */
> +    a = 102;  /* bp for locals 2 */
> +    {
> +      unsigned int val1 = 5;		/* val1-d2 */
> +      a = 103;  /* bp for locals 3 */
> +      {
> +	unsigned int val1 = 6;		/* val1-d3 */
> +	unsigned int val2 = 7;		/* val2-d3 */
> +	unsigned int val3 = 8;		/* val3-d2 */
> +	a = 104;  /* bp for locals 4 */
> +      }
> +    }
> +  }
> +  a = 105; /* bp for locals 5 */
> +}
> +
> +int
> +main (void)
> +{
> +  shadowing ();
> +  return 0;
> +}
> diff --git a/gdb/testsuite/gdb.mi/mi-var-shadowing.exp b/gdb/testsuite/gdb.mi/mi-var-shadowing.exp
> new file mode 100644
> index 00000000000..d0a4c3cd79a
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/mi-var-shadowing.exp
> @@ -0,0 +1,141 @@
> +# Copyright 2023 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +load_lib mi-support.exp
> +set MIFLAGS "-i=mi"
> +
> +gdb_exit
> +if [mi_gdb_start] {
> +    continue
> +}
> +
> +standard_testfile
> +
> +set opts {debug}
> +if [build_executable ${testfile}.exp ${testfile} ${srcfile} $opts] {
> +    return -1
> +}
> +
> +mi_delete_breakpoints
> +mi_gdb_reinitialize_dir $srcdir/$subdir
> +mi_gdb_load ${binfile}
> +mi_runto main
> +
> +set bp_line1 [gdb_get_line_number "bp for locals 1" ${srcfile}]
> +set bp_line2 [gdb_get_line_number "bp for locals 2" ${srcfile}]
> +set bp_line3 [gdb_get_line_number "bp for locals 3" ${srcfile}]
> +set bp_line4 [gdb_get_line_number "bp for locals 4" ${srcfile}]
> +set bp_line5 [gdb_get_line_number "bp for locals 5" ${srcfile}]
> +
> +set val1_d1 [gdb_get_line_number "val1-d1" ${srcfile}]
> +set val1_d2 [gdb_get_line_number "val1-d2" ${srcfile}]
> +set val1_d3 [gdb_get_line_number "val1-d3" ${srcfile}]
> +set val2_d1 [gdb_get_line_number "val2-d1" ${srcfile}]
> +set val2_d2 [gdb_get_line_number "val2-d2" ${srcfile}]
> +set val2_d3 [gdb_get_line_number "val2-d3" ${srcfile}]
> +set val3_d1 [gdb_get_line_number "val3-d1" ${srcfile}]
> +set val3_d2 [gdb_get_line_number "val3-d2" ${srcfile}]
> +set a_line [gdb_get_line_number "entry bp" ${srcfile}]
> +
> +set stack_test1_regx "\\^done,(locals|variables)=\\\[\{name=\"a\",type=\"int\",value=\"$decimal\"\},\{name=\"val1\",type=\"unsigned int\",value=\"1\"\},{name=\"val2\",type=\"unsigned int\",value=\"2\"\}\\\]"
> +set stack_test2_regx "\\^done,(locals|variables)=\\\[\{name=\"val2\",type=\"unsigned int\",value=\"3\",file=\"$srcfile\",line=\"$val2_d2\"\},\{name=\"val3\",type=\"unsigned int\",value=\"4\"\},\{name=\"a\",type=\"int\",value=\"101\"\},\{name=\"val1\",type=\"unsigned int\",value=\"1\"\},\{name=\"val2\",type=\"unsigned int\",value=\"2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"
> +set stack_test3_regx "\\^done,(locals|variables)=\\\[\{name=\"val1\",type=\"unsigned int\",value=\"5\",file=\"$srcfile\",line=\"$val1_d2\"\},\{name=\"val2\",type=\"unsigned int\",value=\"3\",file=\"$srcfile\",line=\"$val2_d2\"\},\{name=\"val3\",type=\"unsigned int\",value=\"4\"\},\{name=\"a\",type=\"int\",value=\"102\"\},\{name=\"val1\",type=\"unsigned int\",value=\"1\",file=\"$srcfile\",line=\"$val1_d1\",shadowed=\"true\"\},\{name=\"val2\",type=\"unsigned int\",value=\"2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"
> +set stack_test4_regx "\\^done,(locals|variables)=\\\[\{name=\"val1\",type=\"unsigned int\",value=\"6\",file=\"$srcfile\",line=\"$val1_d3\"\},\{name=\"val2\",type=\"unsigned int\",value=\"7\",file=\"$srcfile\",line=\"$val2_d3\"\},\{name=\"val3\",type=\"unsigned int\",value=\"8\",file=\"$srcfile\",line=\"$val3_d2\"\},\{name=\"val1\",type=\"unsigned int\",value=\"5\",file=\"$srcfile\",line=\"$val1_d2\",shadowed=\"true\"\},\{name=\"val2\",type=\"unsigned int\",value=\"3\",file=\"$srcfile\",line=\"$val2_d2\",shadowed=\"true\"\},\{name=\"val3\",type=\"unsigned int\",value=\"4\",file=\"$srcfile\",line=\"$val3_d1\",shadowed=\"true\"\},\{name=\"a\",type=\"int\",value=\"103\"\},\{name=\"val1\",type=\"unsigned int\",value=\"1\",file=\"$srcfile\",line=\"$val1_d1\",shadowed=\"true\"\},\{name=\"val2\",type=\"unsigned int\",value=\"2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"
> +set stack_test5_regx "\\^done,(locals|variables)=\\\[\{name=\"a\",type=\"int\",value=\"104\"\},\{name=\"val1\",type=\"unsigned int\",value=\"1\"\},\{name=\"val2\",type=\"unsigned int\",value=\"2\"\}\\\]"
> +
> +mi_gdb_test \
> +    "-break-insert --source ${srcfile} --line ${bp_line1}"  \
> +    "\\^done.*source ${srcfile} \\-line ${bp_line1}.*"  \
> +    "bp at outermost level"
> +mi_execute_to "exec-continue" "breakpoint-hit" ".*" ".*" ".*" "${bp_line1}"  \
> +    { "" "disp=\"keep\"" } "continue to outermost level"
> +mi_gdb_test "-stack-list-locals 0" \
> +    "\\^done,locals=\\\[name=\"a\",name=\"val1\",name=\"val2\"\\\]" \
> +    "-stack-list-locals 0 at outermost level"
> +mi_gdb_test "-stack-list-variables 0" \
> +    "\\^done,variables=\\\[{name=\"a\"},{name=\"val1\"},{name=\"val2\"}\\\]" \
> +    "-stack-list-variables 0 at outermost level"
> +mi_gdb_test "-stack-list-locals 2" "${stack_test1_regx}"  \
> +    "-stack-list-locals 2 at outermost level"
> +mi_gdb_test "-stack-list-variables 2" "${stack_test1_regx}"  \
> +    "-stack-list-variables 2 at outermost level"
> +
> +mi_gdb_test  \
> +    "-break-insert --source ${srcfile} --line ${bp_line2}"  \
> +    "\\^done.*source ${srcfile} \\-line ${bp_line2}.*"  \
> +    "bp at first level"
> +mi_execute_to "exec-continue" "breakpoint-hit" ".*" ".*" ".*" "${bp_line2}"  \
> +    { "" "disp=\"keep\"" } "continue to first level"
> +mi_gdb_test "-stack-list-locals 0"  \
> +    "\\^done,locals=\\\[name=\"val2\",name=\"val3\",name=\"a\",name=\"val1\",name=\"val2\"\\\]"  \
> +    "-stack-list-locals 0 at first level"
> +mi_gdb_test "-stack-list-variables 0" \
> +    "\\^done,variables=\\\[{name=\"val2\",file=\"$srcfile\",line=\"$val2_d2\"},{name=\"val3\"},{name=\"a\"},{name=\"val1\"},{name=\"val2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"  \
> +    "-stack-list-variables 0 at first level"
> +mi_gdb_test "-stack-list-locals 2" "${stack_test2_regx}"  \
> +    "-stack-list-locals 2 at first level"
> +mi_gdb_test "-stack-list-variables 2" "${stack_test2_regx}"  \
> +    "-stack-list-variables 2 at first level"
> +
> +mi_gdb_test  \
> +    "-break-insert --source ${srcfile} --line ${bp_line3}"  \
> +    "\\^done.*source ${srcfile} \\-line ${bp_line3}.*"  \
> +    "bp at second level"
> +mi_execute_to "exec-continue" "breakpoint-hit" ".*" ".*" ".*" "${bp_line3}"  \
> +    { "" "disp=\"keep\"" } "continue to second level"
> +mi_gdb_test "-stack-list-locals 0"  \
> +     "\\^done,locals=\\\[name=\"val1\",name=\"val2\",name=\"val3\",name=\"a\",name=\"val1\",name=\"val2\"\\\]"  \
> +    "-stack-list-locals 0 at second level"
> +mi_gdb_test "-stack-list-variables 0"  \
> +     "\\^done,variables=\\\[{name=\"val1\",file=\"$srcfile\",line=\"$val1_d2\"},{name=\"val2\",file=\"$srcfile\",line=\"$val2_d2\"},{name=\"val3\"},{name=\"a\"},{name=\"val1\",file=\"$srcfile\",line=\"$val1_d1\",shadowed=\"true\"\},{name=\"val2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"  \
> +    "-stack-list-variables 0 at second level"
> +mi_gdb_test "-stack-list-locals 2" "${stack_test3_regx}"  \
> +     "-stack-list-locals 2 at second level"
> +mi_gdb_test "-stack-list-variables 2" "${stack_test3_regx}"  \
> +     "-stack-list-variables 2 at second level"
> +
> +mi_gdb_test  \
> +    "-break-insert --source ${srcfile} --line ${bp_line4}"  \
> +    "\\^done.*source ${srcfile} \\-line ${bp_line4}.*"  \
> +    "bp at third level"
> +mi_execute_to "exec-continue" "breakpoint-hit" ".*" ".*" ".*" "${bp_line4}"  \
> +    { "" "disp=\"keep\"" } "continue to third level"
> +mi_gdb_test "-stack-list-locals 0"  \
> +    "\\^done,locals=\\\[name=\"val1\",name=\"val2\",name=\"val3\",name=\"val1\",name=\"val2\",name=\"val3\",name=\"a\",name=\"val1\",name=\"val2\"\\\]"  \
> +    "-stack-list-locals 0 at third level"
> +mi_gdb_test "-stack-list-variables 0" \
> +    "\\^done,variables=\\\[{name=\"val1\",file=\"$srcfile\",line=\"$val1_d3\"},{name=\"val2\",file=\"$srcfile\",line=\"$val2_d3\"},{name=\"val3\",file=\"$srcfile\",line=\"$val3_d2\"},{name=\"val1\",file=\"$srcfile\",line=\"$val1_d2\",shadowed=\"true\"\},\{name=\"val2\",file=\"$srcfile\",line=\"$val2_d2\",shadowed=\"true\"\},\{name=\"val3\",file=\"$srcfile\",line=\"$val3_d1\",shadowed=\"true\"\},{name=\"a\"},{name=\"val1\",file=\"$srcfile\",line=\"$val1_d1\",shadowed=\"true\"\},{name=\"val2\",file=\"$srcfile\",line=\"$val2_d1\",shadowed=\"true\"\}\\\]"  \
> +    "-stack-list-variables 0 at third level"
> +mi_gdb_test "-stack-list-locals 2" "${stack_test4_regx}"  \
> +    "-stack-list-locals 2 at third level"
> +mi_gdb_test "-stack-list-variables 2" "${stack_test4_regx}"  \
> +    "-stack-list-variables 2 at third level"
> +
> +mi_gdb_test  \
> +    "-break-insert --source ${srcfile} --line ${bp_line5}"  \
> +    "\\^done.*source ${srcfile} \\-line ${bp_line5}.*"  \
> +    "bp at outermost level last"
> +mi_execute_to "exec-continue" "breakpoint-hit" ".*" ".*" ".*" "${bp_line5}"  \
> +    { "" "disp=\"keep\"" } "continue to outermost level last"
> +mi_gdb_test "-stack-list-locals 0"  \
> +    "\\^done,locals=\\\[name=\"a\",name=\"val1\",name=\"val2\"\\\]"  \
> +    "-stack-list-locals 0 at outermost level last"
> +mi_gdb_test "-stack-list-variables 0"  \
> +    "\\^done,variables=\\\[{name=\"a\"},{name=\"val1\"},{name=\"val2\"}\\\]"  \
> +    "-stack-list-variables at outermost level last"
> +mi_gdb_test "-stack-list-locals 2" "${stack_test5_regx}"  \
> +    "-stack-list-locals 2 at outermost level last"
> +mi_gdb_test "-stack-list-variables 2" "${stack_test5_regx}"  \
> +    "-stack-list-variables 2 at outermost level last"