Re: [PATCH v2] gdb/python: add a 'connection_num' attribute to Inferior objects

[Andrew Burgess <andrew.burgess@embecosm.com>]

* Tankut Baris Aktemur via Gdb-patches <gdb-patches@sourceware.org> [2021-04-12 17:04:28 +0200]:

> Define a 'connection_num' attribute for Inferior objects.  The
> read-only attribute is the ID of the process stratum target of an
> inferior, as printed by "info inferiors".
> 
> gdb/ChangeLog:
> 2021-04-12  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
> 
> 	* python/py-inferior.c (infpy_get_connection_num): New function.
> 	(inferior_object_getset): Add a new element for 'connection_num'.
> 	* NEWS: Mention the 'connection_num' attribute of Inferior objects.
> 
> gdb/doc/ChangeLog:
> 2021-04-12  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
> 
> 	* python.texi (Inferiors In Python): Mention the 'connection_num'
> 	attribute.
> 
> gdb/testsuite/ChangeLog:
> 2021-04-12  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
> 
> 	* gdb.python/py-inferior.exp: Add test cases for
> 	* 'connection_num'.

Thanks for looking at this, I had a couple of minor comments.

> ---
>  gdb/NEWS                                 |  5 +++++
>  gdb/doc/python.texi                      |  5 +++++
>  gdb/python/py-inferior.c                 | 16 +++++++++++++++
>  gdb/testsuite/gdb.python/py-inferior.exp | 25 +++++++++++++++++++++++-
>  4 files changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 6cf76a14317..bdc0e2c6593 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -138,6 +138,11 @@ QMemTags
>    Request the remote to store the specified allocation tags to the requested
>    memory range.
>  
> +* Python API
> +
> +  ** Inferior objects now contain a read-only 'connection_num' attribute that
> +     gives the ID of the Inferior's process stratum target.

I don't think you should mention "process stratum" here.  The NEWS
file is for users to read, and "stratum" is not mentioned anywhere in
the GDB manual (or in this NEWS file).

How about:

  ** Inferior objects now contain a read-only 'connection_num' attribute that
     gives the connection number as seen in 'info connections' and
     'info inferiors'.

> +
>  *** Changes in GDB 10
>  
>  * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
> diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
> index 9135d415dd1..b459ff245d4 100644
> --- a/gdb/doc/python.texi
> +++ b/gdb/doc/python.texi
> @@ -2989,6 +2989,11 @@ A @code{gdb.Inferior} object has the following attributes:
>  ID of inferior, as assigned by GDB.
>  @end defvar
>  
> +@defvar Inferior.connection_num
> +ID of inferior's connection (i.e.@: process target), as assigned by
> +@value{GDBN}.
> +@end defvar
> +
>  @defvar Inferior.pid
>  Process ID of the inferior, as assigned by the underlying operating
>  system.
> diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
> index a3d5952a10b..a7fac34f3d6 100644
> --- a/gdb/python/py-inferior.c
> +++ b/gdb/python/py-inferior.c
> @@ -426,6 +426,20 @@ infpy_get_num (PyObject *self, void *closure)
>    return gdb_py_object_from_longest (inf->inferior->num).release ();
>  }
>  
> +static PyObject *
> +infpy_get_connection_num (PyObject *self, void *closure)

This function should have a header comment.

Otherwise, this looks good.

Thanks,
Andrew

> +{
> +  inferior_object *inf = (inferior_object *) self;
> +
> +  INFPY_REQUIRE_VALID (inf);
> +
> +  process_stratum_target *target = inf->inferior->process_target ();
> +  if (target == nullptr)
> +    Py_RETURN_NONE;
> +
> +  return PyLong_FromLong (target->connection_number);
> +}
> +
>  static PyObject *
>  infpy_get_pid (PyObject *self, void *closure)
>  {
> @@ -928,6 +942,8 @@ gdbpy_initialize_inferior (void)
>  static gdb_PyGetSetDef inferior_object_getset[] =
>  {
>    { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
> +  { "connection_num", infpy_get_connection_num, NULL,
> +    "ID of inferior's connection, as assigned by GDB.", NULL },
>    { "pid", infpy_get_pid, NULL, "PID of inferior, as assigned by the OS.",
>      NULL },
>    { "was_attached", infpy_get_was_attached, NULL,
> diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
> index 9df74e05182..2252215b721 100644
> --- a/gdb/testsuite/gdb.python/py-inferior.exp
> +++ b/gdb/testsuite/gdb.python/py-inferior.exp
> @@ -51,6 +51,7 @@ gdb_py_test_silent_cmd "python i0 = inferiors\[0\]" "get first inferior" 0
>  
>  gdb_test "python print ('result = %s' % (i0 == inferiors\[0\]))" " = True" "test equality comparison (true)"
>  gdb_test "python print ('result = %s' % i0.num)" " = \[0-9\]+" "test Inferior.num"
> +gdb_test "python print ('result = %s' % i0.connection_num)" " = \[0-9\]+" "test Inferior.connection_num"
>  gdb_test "python print ('result = %s' % i0.pid)" " = \[0-9\]+" "test Inferior.pid"
>  gdb_test "python print ('result = %s' % i0.was_attached)" " = False" "test Inferior.was_attached"
>  gdb_test "python print (i0.threads ())" "\\(<gdb.InferiorThread object at 0x\[\[:xdigit:\]\]+>,\\)" "test Inferior.threads"
> @@ -262,6 +263,8 @@ with_test_prefix "is_valid" {
>      # correctly.
>      gdb_test "python print (inf_list\[1\].num)" \
>  	"RuntimeError: Inferior no longer exists.*"
> +    gdb_test "python print (inf_list\[1\].connection_num)" \
> +	"RuntimeError: Inferior no longer exists.*"
>      gdb_test "python print (inf_list\[1\].pid)" \
>  	"RuntimeError: Inferior no longer exists.*"
>      gdb_test "python print (inf_list\[1\].was_attached)" \
> @@ -278,10 +281,30 @@ with_test_prefix "is_valid" {
>  with_test_prefix "selected_inferior" {
>      gdb_test "inferior 1" ".*" "switch to first inferior"
>      gdb_test "py print (gdb.selected_inferior().num)" "1" "first inferior selected"
> +    gdb_test "py print (gdb.selected_inferior().connection_num)" "1" \
> +	"first inferior's connection"
> +    # Figure out if inf 1 has a native target.
> +    set inf_1_is_native [gdb_is_target_native]
>  
> -    gdb_test "add-inferior" "Added inferior 3 on connection .*" "create new inferior"
> +    gdb_test "add-inferior -no-connection" "Added inferior 3" "create new inferior"
>      gdb_test "inferior 3" ".*" "switch to third inferior"
>      gdb_test "py print (gdb.selected_inferior().num)" "3" "third inferior selected"
> +    gdb_test "py print (gdb.selected_inferior().connection_num)" "None" \
> +	"third inferior's None connection"
> +    gdb_test "target native" "Done.  Use the \"run\" command to start a process." \
> +	"target for the third inferior"
> +
> +    # If inf 1 has a native target, inf 3's target is shared with 1's.
> +    # Otherwise, it must have created a new target with a new number.
> +    if {$inf_1_is_native} {
> +	set expected_connection_num 1
> +    } else {
> +	set expected_connection_num 2
> +    }
> +    gdb_test "py print (gdb.selected_inferior().connection_num)" \
> +	"$expected_connection_num" \
> +	"third inferior's native connection"
> +
>      gdb_test "inferior 1" ".*" "switch back to first inferior"
>      gdb_test_no_output "remove-inferiors 3" "remove second inferior"
>  }
> -- 
> 2.17.1
>