Re: [PATCH 2/2] Add options to skip unavailable locals

Yao Qi
2013-08-27T05:22:56Z

On 08/27/2013 12:40 AM, Pedro Alves wrote:
> Looks good to me. A few tiny-tiny suggestions below:
>
>> > * NEWS: Mention the new option "--skip-unavailable" to MI
>> > commands '-stack-list-locals' '-stack-list-arguments' and
> ^
> Missing comma.
>

Added.

>> > '-stack-list-variables'.
>
>
>> > Errors are printed as if they would be the parameter value. Use
>> >- zeroed ARG iff it should not be printed according to VALUES. */
>> >+ zeroed ARG iff it should not be printed according to VALUES. If
>> >+ SKIP_UNAVAILABLE is true, print ARG if it is available. */
> "is true, only print ARG"
>

"only" is added here...

>> >
>> > static void
>> > list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
>> >- enum print_values values)
>> >+ enum print_values values, int skip_unavailable)
>> > {
>
>
>> > /* Print a list of the objects for the frame FI in a certain form,
>> > which is determined by VALUES. The objects can be locals,
>> >- arguments or both, which is determined by WHAT. */
>> >+ arguments or both, which is determined by WHAT. If SKIP_UNAVAILABLE
>> >+ is true, print the arguments or local variables whose values are
>> >+ available. */
> "is true, only print the"
>

and here.

Thanks for the review, Pedro. Patch below is what I committed.

--
Yao (é½å°§)

gdb:

2013-08-27 Pedro Alves <pedro@codesourcery.com>
Yao Qi <yao@codesourcery.com>

* mi/mi-cmd-stack.c (list_args_or_locals): Adjust prototype.
(parse_no_frames_option): Remove.
(mi_cmd_stack_list_locals): Handle --skip-unavailable.
(mi_cmd_stack_list_args): Adjust.
(mi_cmd_stack_list_variables): Handle --skip-unavailable.
(list_arg_or_local): Add new parameter 'skip_unavailable'. Return
early if SKIP_UNAVAILABLE is true and ARG->val is unavailable.
Caller update.
(list_args_or_locals): New parameter 'skip_unavailable'.
Handle it.
* valprint.c (scalar_type_p): Rename to ...
(val_print_scalar_type_p): ... this. Make extern.
(val_print, value_check_printable): Adjust.
* valprint.h (val_print_scalar_type_p): Declare.
* value.c (value_entirely_unavailable): New function.
* value.h (value_entirely_unavailable): Declare.

* NEWS: Mention the new option "--skip-unavailable" to MI
commands '-stack-list-locals', '-stack-list-arguments' and
'-stack-list-variables'.

gdb/doc:

2013-08-27 Pedro Alves <pedro@codesourcery.com>
Yao Qi <yao@codesourcery.com>

* gdb.texinfo (GDB/MI Stack Manipulation) <-stack-list-locals>:
Document new --skip-unavailable option.
<-stack-list-variables>: Document new --skip-unavailable option.

gdb/testsuite:

2013-08-27 Yao Qi <yao@codesourcery.com>

* gdb.trace/entry-values.exp: Test unavailable entry value is
not shown when option '--skip-unavailable' is specified.
* gdb.trace/mi-trace-unavailable.exp (test_trace_unavailable):
Add tests for new option '--skip-unavailable'.
---
gdb/NEWS | 4 +
gdb/doc/gdb.texinfo | 17 ++++-
gdb/mi/mi-cmd-stack.c | 77 ++++++++++++++++------
gdb/testsuite/gdb.trace/entry-values.exp | 5 ++
gdb/testsuite/gdb.trace/mi-trace-unavailable.exp | 9 +++
gdb/valprint.c | 8 +-
gdb/valprint.h | 2 +
gdb/value.c | 20 ++++++
gdb/value.h | 4 +
9 files changed, 119 insertions(+), 27 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index 75016c1..ca8baea 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -93,6 +93,10 @@ show range-stepping
** The new command -trace-frame-collected dumps collected variables,
computed expressions, tvars, memory and registers in a traceframe.

+ ** The commands -stack-list-locals, -stack-list-arguments and
+ -stack-list-variables now accept an option "--skip-unavailable".
+ When used, only the available locals or arguments are displayed.
+
* New system-wide configuration scripts
A GDB installation now provides scripts suitable for use as system-wide
configuration scripts for the following systems:
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index c88ee65..21250fe 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -31249,7 +31249,7 @@ For a stack with frame levels 0 through 11:
@subsubheading Synopsis

@smallexample
- -stack-list-arguments [ --no-frame-filters ] @var{print-values}
+ -stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values}
[ @var{low-frame} @var{high-frame} ]
@end smallexample

@@ -31269,6 +31269,9 @@ type and value for simple data types, and the name and type for arrays,
structures and unions. If the option @code{--no-frame-filters} is
supplied, then Python frame filters will not be executed.

+If the @code{--skip-unavailable} option is specified, arguments that
+are not available are not listed. Partially available arguments
+are still displayed, however.

Use of this command to obtain arguments in a single frame is
deprecated in favor of the @samp{-stack-list-variables} command.
@@ -31453,7 +31456,7 @@ Show a single frame:
@subsubheading Synopsis

@smallexample
- -stack-list-locals [ --no-frame-filters ] @var{print-values}
+ -stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values}
@end smallexample

Display the local variable names for the selected frame. If
@@ -31467,6 +31470,10 @@ other data types when the user wishes to explore their values in
more detail. If the option @code{--no-frame-filters} is supplied, then
Python frame filters will not be executed.

+If the @code{--skip-unavailable} option is specified, local variables
+that are not available are not listed. Partially available local
+variables are still displayed, however.
+
This command is deprecated in favor of the
@samp{-stack-list-variables} command.

@@ -31497,7 +31504,7 @@ This command is deprecated in favor of the
@subsubheading Synopsis

@smallexample
- -stack-list-variables [ --no-frame-filters ] @var{print-values}
+ -stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values}
@end smallexample

Display the names of local variables and function arguments for the selected frame. If
@@ -31508,6 +31515,10 @@ type and value for simple data types, and the name and type for arrays,
structures and unions. If the option @code{--no-frame-filters} is
supplied, then Python frame filters will not be executed.

+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.
+
@subsubheading Example

@smallexample
diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index 2df97e2..7bf9ab8 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -39,9 +39,10 @@

enum what_to_list { locals, arguments, all };

-static void list_args_or_locals (enum what_to_list what,
+static void list_args_or_locals (enum what_to_list what,
enum print_values values,
- struct frame_info *fi);
+ struct frame_info *fi,
+ int skip_unavailable);

/* True if we want to allow Python-based frame filters. */
static int frame_filters = 0;
@@ -202,17 +203,21 @@ mi_cmd_stack_list_locals (char *command, char **argv, int argc)
enum py_bt_status result = PY_BT_ERROR;
int print_value;
int oind = 0;
+ int skip_unavailable = 0;
+ int i;

if (argc > 1)
{
int i;
enum opt
{
- NO_FRAME_FILTERS
+ NO_FRAME_FILTERS,
+ SKIP_UNAVAILABLE,
};
static const struct mi_opt opts[] =
{
{"-no-frame-filters", NO_FRAME_FILTERS, 0},
+ {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
{ 0, 0, 0 }
};

@@ -229,6 +234,8 @@ mi_cmd_stack_list_locals (char *command, char **argv, int argc)
{
case NO_FRAME_FILTERS:
raw_arg = oind;
+ case SKIP_UNAVAILABLE:
+ skip_unavailable = 1;
break;
}
}
@@ -237,7 +244,8 @@ mi_cmd_stack_list_locals (char *command, char **argv, int argc)
/* After the last option is parsed, there should be only
'print-values'. */
if (argc - oind != 1)
- error (_("-stack-list-locals: Usage: [--no-frame-filters] PRINT_VALUES"));
+ error (_("-stack-list-locals: Usage: [--no-frame-filters] "
+ "[--skip-unavailable] PRINT_VALUES"));

frame = get_selected_frame (NULL);
print_value = mi_parse_print_values (argv[oind]);
@@ -254,7 +262,8 @@ mi_cmd_stack_list_locals (char *command, char **argv, int argc)
if "--no-frame-filters" has been specified from the command. */
if (! frame_filters || raw_arg || result == PY_BT_NO_FILTERS)
{
- list_args_or_locals (locals, print_value, frame);
+ list_args_or_locals (locals, print_value, frame,
+ skip_unavailable);
}
}

@@ -274,14 +283,17 @@ mi_cmd_stack_list_args (char *command, char **argv, int argc)
struct ui_out *uiout = current_uiout;
int raw_arg = 0;
int oind = 0;
+ int skip_unavailable = 0;
enum py_bt_status result = PY_BT_ERROR;
enum opt
{
NO_FRAME_FILTERS,
+ SKIP_UNAVAILABLE,
};
static const struct mi_opt opts[] =
{
{"-no-frame-filters", NO_FRAME_FILTERS, 0},
+ {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
{ 0, 0, 0 }
};

@@ -298,12 +310,16 @@ mi_cmd_stack_list_args (char *command, char **argv, int argc)
case NO_FRAME_FILTERS:
raw_arg = oind;
break;
+ case SKIP_UNAVAILABLE:
+ skip_unavailable = 1;
+ break;
}
}

if (argc - oind != 1 && argc - oind != 3)
error (_("-stack-list-arguments: Usage: " \
- "[--no-frame-filters] PRINT_VALUES [FRAME_LOW FRAME_HIGH]"));
+ "[--no-frame-filters] [--skip-unavailable] "
+ "PRINT_VALUES [FRAME_LOW FRAME_HIGH]"));

if (argc - oind == 3)
{
@@ -364,7 +380,7 @@ mi_cmd_stack_list_args (char *command, char **argv, int argc)
QUIT;
cleanup_frame = make_cleanup_ui_out_tuple_begin_end (uiout, "frame");
ui_out_field_int (uiout, "level", i);
- list_args_or_locals (arguments, print_values, fi);
+ list_args_or_locals (arguments, print_values, fi, skip_unavailable);
do_cleanups (cleanup_frame);
}
}
@@ -384,17 +400,20 @@ mi_cmd_stack_list_variables (char *command, char **argv, int argc)
enum py_bt_status result = PY_BT_ERROR;
int print_value;
int oind = 0;
+ int skip_unavailable = 0;

if (argc > 1)
{
int i;
enum opt
{
- NO_FRAME_FILTERS
+ NO_FRAME_FILTERS,
+ SKIP_UNAVAILABLE,
};
static const struct mi_opt opts[] =
{
{"-no-frame-filters", NO_FRAME_FILTERS, 0},
+ {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
{ 0, 0, 0 }
};

@@ -411,6 +430,9 @@ mi_cmd_stack_list_variables (char *command, char **argv, int argc)
case NO_FRAME_FILTERS:
raw_arg = oind;
break;
+ case SKIP_UNAVAILABLE:
+ skip_unavailable = 1;
+ break;
}
}
}
@@ -418,8 +440,8 @@ mi_cmd_stack_list_variables (char *command, char **argv, int argc)
/* After the last option is parsed, there should be only
'print-values'. */
if (argc - oind != 1)
- error (_("-stack-list-variables: Usage: " \
- "[--no-frame-filters] PRINT_VALUES"));
+ error (_("-stack-list-variables: Usage: [--no-frame-filters] " \
+ "[--skip-unavailable] PRINT_VALUES"));

frame = get_selected_frame (NULL);
print_value = mi_parse_print_values (argv[oind]);
@@ -436,7 +458,8 @@ mi_cmd_stack_list_variables (char *command, char **argv, int argc)
if "--no-frame-filters" has been specified from the command. */
if (! frame_filters || raw_arg || result == PY_BT_NO_FILTERS)
{
- list_args_or_locals (all, print_value, frame);
+ list_args_or_locals (all, print_value, frame,
+ skip_unavailable);
}
}

@@ -444,19 +467,17 @@ mi_cmd_stack_list_variables (char *command, char **argv, int argc)
WHAT and VALUES see list_args_or_locals.

Errors are printed as if they would be the parameter value. Use
- zeroed ARG iff it should not be printed according to VALUES. */
+ zeroed ARG iff it should not be printed according to VALUES. If
+ SKIP_UNAVAILABLE is true, only print ARG if it is available. */

static void
list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
- enum print_values values)
+ enum print_values values, int skip_unavailable)
{
struct cleanup *old_chain;
struct ui_out *uiout = current_uiout;
struct ui_file *stb;

- stb = mem_fileopen ();
- old_chain = make_cleanup_ui_file_delete (stb);
-
gdb_assert (!arg->val || !arg->error);
gdb_assert ((values == PRINT_NO_VALUES && arg->val == NULL
&& arg->error == NULL)
@@ -467,6 +488,20 @@ list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
|| (arg->entry_kind == print_entry_values_only
&& (arg->val || arg->error)));

+ if (skip_unavailable && arg->val != NULL
+ && (value_entirely_unavailable (arg->val)
+ /* A scalar object that does not have all bits available is
+ also considered unavailable, because all bits contribute
+ to its representation. */
+ || (val_print_scalar_type_p (value_type (arg->val))
+ && !value_bytes_available (arg->val,
+ value_embedded_offset (arg->val),
+ TYPE_LENGTH (value_type (arg->val))))))
+ return;
+
+ stb = mem_fileopen ();
+ old_chain = make_cleanup_ui_file_delete (stb);
+
if (values != PRINT_NO_VALUES || what == all)
make_cleanup_ui_out_tuple_begin_end (uiout, NULL);

@@ -516,11 +551,13 @@ list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,

/* Print a list of the objects for the frame FI in a certain form,
which is determined by VALUES. The objects can be locals,
- arguments or both, which is determined by WHAT. */
+ arguments or both, which is determined by WHAT. If SKIP_UNAVAILABLE
+ is true, only print the arguments or local variables whose values
+ are available. */

static void
list_args_or_locals (enum what_to_list what, enum print_values values,
- struct frame_info *fi)
+ struct frame_info *fi, int skip_unavailable)
{
struct block *block;
struct symbol *sym;
@@ -623,9 +660,9 @@ list_args_or_locals (enum what_to_list what, enum print_values values,
}

if (arg.entry_kind != print_entry_values_only)
- list_arg_or_local (&arg, what, values);
+ list_arg_or_local (&arg, what, values, skip_unavailable);
if (entryarg.entry_kind != print_entry_values_no)
- list_arg_or_local (&entryarg, what, values);
+ list_arg_or_local (&entryarg, what, values, skip_unavailable);
xfree (arg.error);
xfree (entryarg.error);
}
diff --git a/gdb/testsuite/gdb.trace/entry-values.exp b/gdb/testsuite/gdb.trace/entry-values.exp
index bb62e5d..85306ad 100644
--- a/gdb/testsuite/gdb.trace/entry-values.exp
+++ b/gdb/testsuite/gdb.trace/entry-values.exp
@@ -276,4 +276,9 @@ gdb_test "tfind" "Found trace frame 0, .*" "tfind start"
# Since 'global2' is not collected, j@entry is expected to be 'unavailable'.
gdb_test "bt 1" "#0 .* foo \\(i=\[-\]?$decimal, i@entry=2, j=\[-\]?$decimal, j@entry=<unavailable>\\).*"

+# Test that unavailable "j@entry" is not shown when command option
+# --skip-unavailable is used.
+gdb_test "interpreter-exec mi \"-stack-list-arguments --skip-unavailable --simple-values\"" \
+ "\r\n\\^done,stack-args=\\\[frame={level=\"0\",args=\\\[{name=\"i\",type=\"int\",value=\".*\"},{name=\"i@entry\",type=\"int\",value=\"2\"},{name=\"j\",type=\"int\",value=\".*\"}\\\]},frame=.*\\\].*"
+
gdb_test "tfind" "Target failed to find requested trace frame\..*"
diff --git a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
index d96ec8b..c69891b 100644
--- a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
+++ b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
@@ -106,16 +106,25 @@ proc test_trace_unavailable { data_source } {
mi_gdb_test "-stack-list-locals --simple-values" \
".*\\^done,locals=\\\[\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\},\{name=\"i\",type=\"int\",value=\"<unavailable>\"\}\\\]" \
"-stack-list-locals --simple-values"
+ mi_gdb_test "-stack-list-locals --skip-unavailable --simple-values" \
+ ".*\\^done,locals=\\\[\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\}\\\]" \
+ "-stack-list-locals --skip-unavailable --simple-values"

# Test MI command '-stack-list-arguments'.
mi_gdb_test "-stack-list-arguments --simple-values" \
".*\\^done,stack-args=\\\[frame=\{level=\"0\",args=\\\[\{name=\"j\",type=\"int\",value=\"4\"\},\{name=\"s\",type=\"char \\\*\",value=\"<unavailable>\"\}\\\]\},.*\}.*" \
"-stack-list-arguments --simple-values"
+ mi_gdb_test "-stack-list-arguments --skip-unavailable --simple-values" \
+ ".*\\^done,stack-args=\\\[frame=\{level=\"0\",args=\\\[\{name=\"j\",type=\"int\",value=\"4\"\}\\\]\},.*\}.*" \
+ "-stack-list-arguments --skip-unavailable --simple-values"

# Test MI command '-stack-list-variables'.
mi_gdb_test "-stack-list-variables --simple-values" \
".*\\^done,variables=\\\[\{name=\"j\",arg=\"1\",type=\"int\",value=\"4\"\},\{name=\"s\",arg=\"1\",type=\"char \\\*\",value=\"<unavailable>\"\},\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\},\{name=\"i\",type=\"int\",value=\"<unavailable>\"\}\\\]" \
"-stack-list-variables --simple-values"
+ mi_gdb_test "-stack-list-variables --skip-unavailable --simple-values" \
+ ".*\\^done,variables=\\\[\{name=\"j\",arg=\"1\",type=\"int\",value=\"4\"\},\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\}\\\]" \
+ "-stack-list-variables --skip-unavailable --simple-values"

mi_gdb_test "-trace-find frame-number 1" \
".*\\^done,found=\"1\",tracepoint=\"${decimal}\",traceframe=\"1\",frame=\{.*" \
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 753ae34..0f6d65e 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -275,8 +275,8 @@ show_symbol_print (struct ui_file *file, int from_tty,
we want to print scalar arguments, but not aggregate arguments.
This function distinguishes between the two. */

-static int
-scalar_type_p (struct type *type)
+int
+val_print_scalar_type_p (struct type *type)
{
CHECK_TYPEDEF (type);
while (TYPE_CODE (type) == TYPE_CODE_REF)
@@ -770,7 +770,7 @@ val_print (struct type *type, const gdb_byte *valaddr, int embedded_offset,

/* Handle summary mode. If the value is a scalar, print it;
otherwise, print an ellipsis. */
- if (options->summary && !scalar_type_p (type))
+ if (options->summary && !val_print_scalar_type_p (type))
{
fprintf_filtered (stream, "...");
return;
@@ -802,7 +802,7 @@ value_check_printable (struct value *val, struct ui_file *stream,

if (value_entirely_optimized_out (val))
{
- if (options->summary && !scalar_type_p (value_type (val)))
+ if (options->summary && !val_print_scalar_type_p (value_type (val)))
fprintf_filtered (stream, "...");
else
val_print_optimized_out (stream);
diff --git a/gdb/valprint.h b/gdb/valprint.h
index 2959098..e7073b6 100644
--- a/gdb/valprint.h
+++ b/gdb/valprint.h
@@ -211,4 +211,6 @@ extern void generic_printstr (struct ui_file *stream, struct type *type,

extern void output_command_const (const char *args, int from_tty);

+extern int val_print_scalar_type_p (struct type *type);
+
#endif
diff --git a/gdb/value.c b/gdb/value.c
index 09ab1bb..d96c07b 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -353,6 +353,26 @@ value_entirely_available (struct value *value)
return 0;
}

+int
+value_entirely_unavailable (struct value *value)
+{
+ /* We can only tell whether the whole value is available when we try
+ to read it. */
+ if (value->lazy)
+ value_fetch_lazy (value);
+
+ if (VEC_length (range_s, value->unavailable) == 1)
+ {
+ struct range *t = VEC_index (range_s, value->unavailable, 0);
+
+ if (t->offset == 0
+ && t->length == TYPE_LENGTH (value_enclosing_type (value)))
+ return 1;
+ }
+
+ return 0;
+}
+
void
mark_value_bytes_unavailable (struct value *value, int offset, int length)
{
diff --git a/gdb/value.h b/gdb/value.h
index bef193c..f03cf76 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -435,6 +435,10 @@ extern int value_bytes_available (const struct value *value,
whole object is unavailable. */
extern int value_entirely_available (struct value *value);

+/* Like value_entirely_available, but return false if any byte in the
+ whole object is available. */
+extern int value_entirely_unavailable (struct value *value);
+
/* Mark VALUE's content bytes starting at OFFSET and extending for
LENGTH bytes as unavailable. */

--
1.7.7.6