[PATCH v7] gdb/python: Add BreakpointLocation type

[PATCH v7] gdb/python: Add BreakpointLocation type

[Simon Farre via Gdb-patches]

PR python/18385

v7:
This version addresses the issues pointed out by Tom.

Added nullchecks for Python object creations.

Changed from using PyLong_FromLong to the gdb_py-versions.

Re-factored some code to make it look more cohesive.

Also added the more safe Python reference count decrement PY_XDECREF,
even though the BreakpointLocation type is never instantiated by the
user (explicitly documented in the docs) decrementing < 0 is made
impossible with the safe call.

Tom pointed out that using the policy class explicitly to decrement a
reference counted object was not the way to go, so this has instead been
wrapped in a ref_ptr that handles that for us in blocpy_dealloc.

Moved macro from py-internal to py-breakpoint.c.

Renamed section at the bottom of commit message "Patch Description".

v6:
This version addresses the points Pedro gave in review to this patch.

Added the attributes `function`, `fullname` and `thread_groups`
as per request by Pedro with the argument that it more resembles the
output of the MI-command "-break-list".  Added documentation for these attributes.

Cleaned up left overs from copy+paste in test suite, removed hard coding
of line numbers where possible.

Refactored some code to use more c++-y style range for loops
wrt to breakpoint locations.

Changed terminology, naming was very inconsistent. Used a variety of "parent",
"owner". Now "owner" is the only term used, and the field in the
gdb_breakpoint_location_object now also called "owner".

v5:

Changes in response to review by Tom Tromey:
- Replaced manual INCREF/DECREF calls with
  gdbpy_ref ptrs in places where possible.
- Fixed non-gdb style conforming formatting
- Get parent of bploc increases ref count of parent.
- moved bploc Python definition to py-breakpoint.c

The INCREF of self in bppy_get_locations is due
to the individual locations holding a reference to
it's owner. This is decremented at de-alloc time.

The reason why this needs to be here is, if the user writes
for instance;

py loc = gdb.breakpoints()[X].locations[Y]

The breakpoint owner object is immediately going
out of scope (GC'd/dealloced), and the location
object requires it to be alive for as long as it is alive.

Thanks for your review, Tom!

v4:
Fixed remaining doc issues as per request
by Eli.

v3:
Rewritten commit message, shortened + reworded,
added tests.

Patch Description

Currently, the Python API lacks the ability to
query breakpoints for their installed locations,
and subsequently, can't query any information about them, or
enable/disable individual locations.

This patch solves this by adding Python type gdb.BreakpointLocation.
The type is never instantiated by the user of the Python API directly,
but is produced by the gdb.Breakpoint.locations attribute returning
a list of gdb.BreakpointLocation.

gdb.Breakpoint.locations:
The attribute for retrieving the currently installed breakpoint
locations for gdb.Breakpoint. Matches behavior of
the "info breakpoints" command in that it only
returns the last known or currently inserted breakpoint locations.

BreakpointLocation contains 7 attributes

6 read-only attributes:
owner: location owner's Python companion object
source: file path and line number tuple: (string, long) / None
address: installed address of the location
function: function name where location was set
fullname: fullname where location was set
thread_groups: thread groups (inferiors) where location was set.

1 writeable attribute:
enabled: get/set enable/disable this location (bool)

Access/calls to these, can all throw Python exceptions (documented in
the online documentation), and that's due to the nature
of how breakpoint locations can be invalidated
"behind the scenes", either by them being removed
from the original breakpoint or changed,
like for instance when a new symbol file is loaded, at
which point all breakpoint locations are re-created by GDB.
Therefore this patch has chosen to be non-intrusive:
it's up to the Python user to re-request the locations if
they become invalid.

Also there's event handlers that handle new object files etc, if a Python
user is storing breakpoint locations in some larger state they've
built up, refreshing the locations is easy and it only comes
with runtime overhead when the Python user wants to use them.

gdb.BreakpointLocation Python type
struct "gdbpy_breakpoint_location_object" is found in python-internal.h

Its definition, layout, methods and functions
are found in the same file as gdb.Breakpoint (py-breakpoint.c)

1 change was also made to breakpoint.h/c to make it possible
to enable and disable a bp_location* specifically,
without having its LOC_NUM, as this number
also can change arbitrarily behind the scenes.

Updated docs & news file as per request.

Testsuite: tests the .source attribute and the disabling of
individual locations.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18385
---
 gdb/NEWS                                     |   5 +
 gdb/breakpoint.c                             |  59 ++++
 gdb/breakpoint.h                             |   5 +
 gdb/doc/python.texi                          |  71 +++++
 gdb/python/py-breakpoint.c                   | 309 +++++++++++++++++++
 gdb/python/python-internal.h                 |   4 +-
 gdb/python/python.c                          |   1 +
 gdb/testsuite/gdb.python/py-bp-locations.c   |  32 ++
 gdb/testsuite/gdb.python/py-bp-locations.exp |  64 ++++
 9 files changed, 548 insertions(+), 2 deletions(-)
 create mode 100644 gdb/testsuite/gdb.python/py-bp-locations.c
 create mode 100644 gdb/testsuite/gdb.python/py-bp-locations.exp

diff --git a/gdb/NEWS b/gdb/NEWS
index 760cb2b7abc..96b6ae04684 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -38,6 +38,11 @@ maintenance info line-table
      This is the same format that GDB uses when printing address, symbol,
      and offset information from the disassembler.
 
+  ** New Python type gdb.BreakpointLocation.
+     The new attribute 'locations' of gdb.Breakpoint returns a list of
+     gdb.BreakpointLocation objects specifying the locations where the
+     breakpoint is inserted into the debuggee.
+
 *** Changes in GDB 12
 
 * DBX mode is deprecated, and will be removed in GDB 13
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index b21d83d8019..716c57e055b 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -175,6 +175,8 @@ static void enable_breakpoint_disp (struct breakpoint *, enum bpdisp,
 
 static void decref_bp_location (struct bp_location **loc);
 
+static int find_loc_num_by_location (bp_location* loc);
+
 static struct bp_location *allocate_bp_location (struct breakpoint *bpt);
 
 /* update_global_location_list's modes of operation wrt to whether to
@@ -13660,6 +13662,63 @@ enable_disable_bp_num_loc (int bp_num, int loc_num, bool enable)
   gdb::observers::breakpoint_modified.notify (loc->owner);
 }
 
+/* Enable or disable a breakpoint location LOC.  ENABLE
+   specifies whether to enable or disable.  */
+
+void
+enable_disable_bp_location (bp_location *loc, bool enable)
+{
+  if (loc == nullptr)
+    error (_("Breakpoint location is invalid."));
+
+  if (loc->owner == nullptr)
+    error (_("Breakpoint location does not have an owner breakpoint."));
+
+  if (loc->disabled_by_cond && enable)
+    {
+      int loc_num = find_loc_num_by_location (loc);
+      if (loc_num == -1)
+	error (_("Breakpoint location LOC_NUM could not be found."));
+      else
+	error (_("Breakpoint %d's condition is invalid at location %d, "
+		"cannot enable."), loc->owner->number, loc_num);
+    }
+
+  if (loc->enabled != enable)
+    {
+      loc->enabled = enable;
+      mark_breakpoint_location_modified (loc);
+    }
+
+  if (target_supports_enable_disable_tracepoint ()
+	  && current_trace_status ()->running && loc->owner
+	  && is_tracepoint (loc->owner))
+	  target_disable_tracepoint (loc);
+
+  update_global_location_list (UGLL_DONT_INSERT);
+  gdb::observers::breakpoint_modified.notify (loc->owner);
+}
+
+/* Calculates LOC_NUM for LOC by traversing the bp_location chain of LOC's
+   owner.  1-based indexing.  -1 signals NOT FOUND.  */
+
+static int
+find_loc_num_by_location (bp_location *loc)
+{
+  if (loc != nullptr && loc->owner != nullptr)
+    {
+      /* Locations use 1-based indexing.  */
+      int loc_num = 1;
+      for (bp_location *it : loc->owner->locations ())
+	{
+	  if (it == loc)
+	    return loc_num;
+	  loc_num++;
+	}
+    }
+  return -1;
+}
+
 /* Enable or disable a range of breakpoint locations.  BP_NUM is the
    number of the breakpoint, and BP_LOC_RANGE specifies the
    (inclusive) range of location numbers of that breakpoint to
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index e412c4d4113..b39aaef9c16 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1803,4 +1803,9 @@ extern void catch_exception_event (enum exception_event_kind ex_event,
 				   const char *regex, bool tempflag,
 				   int from_tty);
 
+/* Enable or disable a breakpoint location LOC.  ENABLE
+   specifies whether to enable or disable.  */
+
+extern void enable_disable_bp_location (bp_location *loc, bool enable);
+
 #endif /* !defined (BREAKPOINT_H) */
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 7c414b01d70..8fc9aaeff3d 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -6046,6 +6046,15 @@ the user.  It is a string.  If the breakpoint does not have a location
 attribute is not writable.
 @end defvar
 
+@defvar Breakpoint.locations
+Get the most current list of breakpoint locations that are inserted for this
+breakpoint, with elements of type @code{gdb.BreakpointLocation}
+(described below).  This functionality matches that of the
+@code{info breakpoint} command (@pxref{Set Breaks}), in that it only retrieves
+the most current list of locations, thus the list itself when returned is
+not updated behind the scenes.  This attribute is not writable.
+@end defvar
+
 @defvar Breakpoint.expression
 This attribute holds a breakpoint expression, as specified by
 the user.  It is a string.  If the breakpoint does not have an
@@ -6066,6 +6075,68 @@ commands, separated by newlines.  If there are no commands, this
 attribute is @code{None}.  This attribute is writable.
 @end defvar
 
+@subheading Breakpoint Locations
+
+A breakpoint location is one of the actual places where a breakpoint has been
+set, represented in the Python API by the @code{gdb.BreakpointLocation}
+type.  This type is never instantiated by the user directly, but is retrieved
+from @code{Breakpoint.locations} which returns a list of breakpoint
+locations where it is currently set.  Breakpoint locations can become
+invalid if new symbol files are loaded or dynamically loaded libraries are
+closed.  Accessing the attributes of an invalidated breakpoint location will
+throw a @code{RuntimeError} exception.  Access the @code{Breakpoint.locations}
+attribute again to retrieve the new and valid breakpoints location list.
+
+@defvar BreakpointLocation.source
+This attribute returns the source file path and line number where this location
+was set. The type of the attribute is a tuple of @var{string} and
+@var{long}.  If the breakpoint location doesn't have a source location,
+it returns None, which is the case for watchpoints and catchpoints.
+This will throw a @code{RuntimeError} exception if the location
+has been invalidated. This attribute is not writable.
+@end defvar
+
+@defvar BreakpointLocation.address
+This attribute returns the address where this location was set.
+This attribute is of type long.  This will throw a @code{RuntimeError}
+exception if the location has been invalidated.  This attribute is
+not writable.
+@end defvar
+
+@defvar BreakpointLocation.enabled
+This attribute holds the value for whether or not this location is enabled.
+This attribute is writable (boolean).  This will throw a @code{RuntimeError}
+exception if the location has been invalidated.
+@end defvar
+
+@defvar BreakpointLocation.owner
+This attribute holds a reference to the @code{gdb.Breakpoint} owner object,
+from which this @code{gdb.BreakpointLocation} was retrieved from.
+This will throw a @code{RuntimeError} exception if the location has been
+invalidated.  This attribute is not writable.
+@end defvar
+
+@defvar BreakpointLocation.function
+This attribute gets the name of the function where this location was set.
+If no function could be found this attribute returns @code{None}.
+This will throw a @code{RuntimeError} exception if the location has
+been invalidated.  This attribute is not writable.
+@end defvar
+
+@defvar BreakpointLocation.fullname
+This attribute gets the full name of where this location was set.  If no
+full name could be found, this attribute returns @code{None}.
+This will throw a @code{RuntimeError} exception if the location has
+been invalidated.  This attribute is not writable.
+@end defvar
+
+@defvar BreakpointLocation.thread_groups
+This attribute gets the thread groups it was set in.  It returns a @code{List}
+of the thread group ID's.  This will throw a @code{RuntimeError}
+exception if the location has been invalidated.  This attribute
+is not writable.
+@end defvar
+
 @node Finish Breakpoints in Python
 @subsubsection Finish Breakpoints
 
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 74de0d90e23..4b39fcd2292 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -34,6 +34,41 @@
 #include "py-event.h"
 #include "linespec.h"
 
+extern PyTypeObject breakpoint_location_object_type
+    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("breakpoint_location_object");
+
+struct gdbpy_breakpoint_location_object
+{
+  PyObject_HEAD
+
+  /* An owning reference to the gdb breakpoint location object.  */
+  bp_location *bp_loc;
+
+  /* An owning reference to the location's breakpoint owner.  */
+  gdbpy_breakpoint_object *owner;
+};
+
+/* Require that BREAKPOINT and LOCATION->OWNER are the same; throw a Python
+   exception if they are not.  */
+#define BPLOCPY_REQUIRE_VALID(Breakpoint, Location)                         \
+    do {                                                                    \
+      if ((Breakpoint)->bp != (Location)->bp_loc->owner)                    \
+	return PyErr_Format (PyExc_RuntimeError,                            \
+          _("Breakpoint location is invalid."));                            \
+    } while (0)
+
+/* Require that BREAKPOINT and LOCATION->OWNER are the same; throw a Python
+   exception if they are not.  This macro is for use in setter functions.  */
+#define BPLOCPY_SET_REQUIRE_VALID(Breakpoint, Location)                     \
+    do {                                                                    \
+      if ((Breakpoint)->bp != (Location)->bp_loc->owner)                    \
+	{                                                                   \
+	  PyErr_Format (PyExc_RuntimeError,                                 \
+			_("Breakpoint location is invalid."));              \
+	  return -1;                                                        \
+	}                                                                   \
+    } while (0)
+
 /* Debugging of Python breakpoints.  */
 
 static bool pybp_debug;
@@ -692,6 +727,38 @@ bppy_get_ignore_count (PyObject *self, void *closure)
   return gdb_py_object_from_longest (self_bp->bp->ignore_count).release ();
 }
 
+/* Python function to get the breakpoint locations of an owner breakpoint.  */
+
+static PyObject*
+bppy_get_locations (PyObject *self, void *closure)
+{
+  using py_bploc_t = gdbpy_breakpoint_location_object;
+  auto *self_bp = (gdbpy_breakpoint_object *) self;
+  BPPY_REQUIRE_VALID (self_bp);
+
+  gdbpy_ref<> list (PyList_New (0));
+  if (list == nullptr)
+    return nullptr;
+
+  for (bp_location *loc : self_bp->bp->locations ())
+    {
+      gdbpy_ref<py_bploc_t> py_bploc (PyObject_New (py_bploc_t,
+				    &breakpoint_location_object_type));
+      if (py_bploc == nullptr)
+	return nullptr;
+
+      bp_location_ref_ptr ref = bp_location_ref_ptr::new_reference (loc);
+      /* The location takes a reference to the owner breakpoint.  Decrements
+         when they are de-allocated in bplocpy_dealloc */
+      Py_INCREF (self);
+      py_bploc->owner = self_bp;
+      py_bploc->bp_loc = ref.release ();
+      if (PyList_Append (list.get (), (PyObject *) py_bploc.get ()) != 0)
+	return nullptr;
+    }
+  return list.release ();
+}
+
 /* Internal function to validate the Python parameters/keywords
    provided to bppy_init.  */
 
@@ -1182,6 +1249,20 @@ gdbpy_initialize_breakpoints (void)
   return 0;
 }
 
+/* Initialize the Python BreakpointLocation code.  */
+
+int
+gdbpy_initialize_breakpoint_locations ()
+{
+  if (PyType_Ready (&breakpoint_location_object_type) < 0)
+    return -1;
+
+  if (gdb_pymodule_addobject (gdb_module, "BreakpointLocation",
+			(PyObject *) &breakpoint_location_object_type) < 0)
+    return -1;
+  return 0;
+}
+
 \f
 
 /* Helper function that overrides this Python object's
@@ -1264,6 +1345,8 @@ or None if no condition set."},
     "Whether this breakpoint is a temporary breakpoint."},
   { "pending", bppy_get_pending, NULL,
     "Whether this breakpoint is a pending breakpoint."},
+  { "locations", bppy_get_locations, NULL,
+    "Get locations where this breakpoint was set"},
   { NULL }  /* Sentinel.  */
 };
 
@@ -1330,3 +1413,229 @@ _initialize_py_breakpoint ()
 	show_pybp_debug,
 	&setdebuglist, &showdebuglist);
 }
+
+/* Python function to set the enabled state of a breakpoint location.  */
+
+static int
+bplocpy_set_enabled (PyObject *py_self, PyObject *newvalue, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_SET_REQUIRE_VALID (self->owner);
+  BPLOCPY_SET_REQUIRE_VALID (self->owner, self);
+
+  if (newvalue == nullptr)
+    {
+      PyErr_SetString (PyExc_TypeError,
+			_("Cannot delete 'enabled' attribute."));
+      return -1;
+    }
+  else if (!PyBool_Check (newvalue))
+    {
+      PyErr_SetString (PyExc_TypeError,
+			_("The value of 'enabled' must be a boolean."));
+      return -1;
+    }
+
+  int cmp = PyObject_IsTrue (newvalue);
+  if (cmp < 0)
+    return -1;
+
+  try
+    {
+      enable_disable_bp_location (self->bp_loc, cmp == 1);
+    }
+  catch (const gdb_exception &except)
+    {
+      GDB_PY_SET_HANDLE_EXCEPTION (except);
+    }
+  return 0;
+}
+
+/* Python function to test whether or not the breakpoint location is enabled.  */
+
+static PyObject *
+bplocpy_get_enabled (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+
+  if (self->bp_loc->enabled)
+    Py_RETURN_TRUE;
+  else
+    Py_RETURN_FALSE;
+}
+
+/* Python function to get address of breakpoint location.  */
+
+static PyObject *
+bplocpy_get_address (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  return gdb_py_object_from_ulongest (self->bp_loc->address).release ();
+}
+
+/* Python function to get owner of breakpoint location, which
+   is of type gdb.Breakpoint.  */
+
+static PyObject *
+bplocpy_get_owner (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  Py_INCREF (self->owner);
+  return (PyObject *) self->owner;
+}
+
+/* Python function to get the source file name path and line number
+   where this breakpoint location was set.   */
+
+static PyObject *
+bplocpy_get_source_location (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  if (self->bp_loc->symtab)
+    {
+      gdbpy_ref<> tup (PyTuple_New (2));
+      if (tup == nullptr)
+	return nullptr;
+      /* symtab->filename is never NULL. */
+      gdbpy_ref<> filename
+	= host_string_to_python_string (self->bp_loc->symtab->filename);
+      if (filename == nullptr)
+	return nullptr;
+      auto line = gdb_py_object_from_ulongest (self->bp_loc->line_number);
+      if (PyTuple_SetItem (tup.get (), 0, filename.release ()) == -1
+	  || PyTuple_SetItem (tup.get (), 1, line.release ()) == -1)
+	return nullptr;
+      return tup.release ();
+    }
+  else
+    Py_RETURN_NONE;
+}
+
+/* Python function to get the function name of where this location was set.  */
+
+static PyObject *
+bplocpy_get_function (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  const auto fn_name = self->bp_loc->function_name.get ();
+  if (fn_name != nullptr)
+    return host_string_to_python_string (fn_name).release ();
+  Py_RETURN_NONE;
+}
+
+static PyObject *
+bplocpy_get_thread_groups (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  gdbpy_ref<> list (PyList_New (0));
+  if (list == nullptr)
+    return nullptr;
+  for (inferior *inf : all_inferiors ())
+    {
+      if (inf->pspace == self->bp_loc->pspace)
+	if (PyList_Append (list.get (),
+	    gdb_py_object_from_ulongest(inf->num).release()) != 0)
+	  return nullptr;
+    }
+  return list.release ();
+}
+
+static PyObject *
+bplocpy_get_fullname (PyObject *py_self, void *closure)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  BPPY_REQUIRE_VALID (self->owner);
+  BPLOCPY_REQUIRE_VALID (self->owner, self);
+  const auto symtab = self->bp_loc->symtab;
+  if (symtab != nullptr && symtab->fullname != nullptr)
+    {
+      gdbpy_ref<> fullname
+	= host_string_to_python_string (symtab->fullname);
+      return fullname.release ();
+    }
+  Py_RETURN_NONE;
+}
+
+/* De-allocation function to be called for the Python object.  */
+
+static void
+bplocpy_dealloc (PyObject *py_self)
+{
+  auto *self = (gdbpy_breakpoint_location_object *) py_self;
+  bp_location_ref_ptr decrementing_ref {self->bp_loc};
+  Py_XDECREF (self->owner);
+  Py_TYPE (py_self)->tp_free (py_self);
+}
+
+/* Attribute get/set Python definitions. */
+
+static gdb_PyGetSetDef bp_location_object_getset[] = {
+  { "enabled", bplocpy_get_enabled, bplocpy_set_enabled,
+    "Boolean telling whether the breakpoint is enabled.", NULL },
+  { "owner", bplocpy_get_owner, NULL,
+    "Get the breakpoint owner object", NULL },
+  { "address", bplocpy_get_address, NULL,
+    "Get address of where this location was set", NULL},
+  { "source", bplocpy_get_source_location, NULL,
+    "Get file and line number of where this location was set", NULL},
+  { "function", bplocpy_get_function, NULL,
+    "Get function of where this location was set", NULL },
+  { "fullname", bplocpy_get_fullname, NULL,
+    "Get fullname of where this location was set", NULL },
+  { "thread_groups", bplocpy_get_thread_groups, NULL,
+    "Get thread groups where this location is in", NULL },
+  { NULL }  /* Sentinel.  */
+};
+
+PyTypeObject breakpoint_location_object_type =
+{
+  PyVarObject_HEAD_INIT (NULL, 0)
+  "gdb.BreakpointLocation",		/*tp_name*/
+  sizeof (gdbpy_breakpoint_location_object), /*tp_basicsize*/
+  0,					/*tp_itemsize*/
+  bplocpy_dealloc,  			/*tp_dealloc*/
+  0,					/*tp_print*/
+  0,					/*tp_getattr*/
+  0,					/*tp_setattr*/
+  0,					/*tp_compare*/
+  0,					/*tp_repr*/
+  0,					/*tp_as_number*/
+  0,					/*tp_as_sequence*/
+  0,					/*tp_as_mapping*/
+  0,					/*tp_hash */
+  0,					/*tp_call*/
+  0,					/*tp_str*/
+  0,					/*tp_getattro*/
+  0,          				/*tp_setattro */
+  0,					/*tp_as_buffer*/
+  Py_TPFLAGS_DEFAULT,			/*tp_flags*/
+  "GDB breakpoint location object",	/* tp_doc */
+  0,					/* tp_traverse */
+  0,					/* tp_clear */
+  0,					/* tp_richcompare */
+  0,					/* tp_weaklistoffset */
+  0,					/* tp_iter */
+  0,					/* tp_iternext */
+  0,					/* tp_methods */
+  0,					/* tp_members */
+  bp_location_object_getset,		/* tp_getset */
+  0,					/* tp_base */
+  0,					/* tp_dict */
+  0,					/* tp_descr_get */
+  0,					/* tp_descr_set */
+  0,					/* tp_dictoffset */
+  0,					/* tp_init */
+  0,					/* tp_alloc */
+};
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index d947b96033b..7c4648e6042 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -322,12 +322,10 @@ struct gdbpy_breakpoint_object
 	}                                                               \
     } while (0)
 
-
 /* Variables used to pass information between the Breakpoint
    constructor and the breakpoint-created hook function.  */
 extern gdbpy_breakpoint_object *bppy_pending_object;
 
-
 struct thread_object
 {
   PyObject_HEAD
@@ -505,6 +503,8 @@ int gdbpy_initialize_objfile (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_breakpoints (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_breakpoint_locations ()
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_finishbreakpoints (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_lazy_string (void)
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 7a9c8c1b66e..479cf6a296a 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -2057,6 +2057,7 @@ do_start_initialization ()
       || gdbpy_initialize_pspace () < 0
       || gdbpy_initialize_objfile () < 0
       || gdbpy_initialize_breakpoints () < 0
+      || gdbpy_initialize_breakpoint_locations () < 0
       || gdbpy_initialize_finishbreakpoints () < 0
       || gdbpy_initialize_lazy_string () < 0
       || gdbpy_initialize_linetable () < 0
diff --git a/gdb/testsuite/gdb.python/py-bp-locations.c b/gdb/testsuite/gdb.python/py-bp-locations.c
new file mode 100644
index 00000000000..072bf3d6c12
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-bp-locations.c
@@ -0,0 +1,32 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2022-2022 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/>.  */
+
+short add (short a, short b)
+{
+  return a + b;
+}
+
+int add (int c, int d)
+{
+  return c + d;
+}
+
+int main (void)
+{
+  short sum_a = add (2, 4);
+  int sum_b = add (2, 4);
+}
\ No newline at end of file
diff --git a/gdb/testsuite/gdb.python/py-bp-locations.exp b/gdb/testsuite/gdb.python/py-bp-locations.exp
new file mode 100644
index 00000000000..97a4fde2c0b
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-bp-locations.exp
@@ -0,0 +1,64 @@
+# Copyright (C) 2022-2022 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 gdb-python.exp
+
+standard_testfile
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {c++ debug}] != "" } {
+    return -1
+}
+
+save_vars { GDBFLAGS } {
+    clean_restart $testfile
+}
+
+if { [skip_python_tests] } { continue }
+
+if ![runto_main] {
+    return -1
+}
+
+# Set breakpoint with 2 locations.
+gdb_breakpoint "add"
+
+set expected_line_a [gdb_get_line_number "a + b"]
+set expected_line_b [gdb_get_line_number "c + d"]
+
+# Test that the locations return correct source locations.
+gdb_test "python print(gdb.breakpoints()\[1\].locations\[0\].source)" \
+	 ".*('.*py-bp-locations.c', $expected_line_a).*"
+gdb_test "python print(gdb.breakpoints()\[1\].locations\[1\].source)" \
+	 ".*('.*py-bp-locations.c', $expected_line_b).*"
+
+# Disable first location and make sure we don't hit it.
+gdb_test "python gdb.breakpoints()\[1\].locations\[0\].enabled = False" ""
+gdb_continue_to_breakpoint "" ".*25.*"
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint "add"
+# Disable "add" owner breakpoint and verify all locations still are enabled.
+gdb_test "python gdb.breakpoints()\[1\].enabled = False" "" "Disable add owner breakpoint."
+
+gdb_test "python print(gdb.breakpoints()\[1\].locations\[0\].enabled)" "True" "First location still enabled"
+
+gdb_test "python print(gdb.breakpoints()\[1\].locations\[1\].enabled)" "True" "Second location still enabled"
+
+# Set breakpoint at end and make sure we run past the still enabled locations,
+gdb_breakpoint 32
+gdb_continue_to_breakpoint "end of main" ".*32.*"

base-commit: 04f4c17c7a14ebb6c2212267b2ebc83f1376fe20
-- 
2.34.1

Re: [PATCH v7] gdb/python: Add BreakpointLocation type

[Tom Tromey via Gdb-patches]

>>>>> "Simon" == Simon Farre via Gdb-patches <gdb-patches@sourceware.org> writes:

Simon> +static int find_loc_num_by_location (bp_location* loc);

I think it would be better to rearrange this so that the forward
declaration isn't needed.

Simon> +@defvar Breakpoint.locations
Simon> +Get the most current list of breakpoint locations that are inserted for this
Simon> +breakpoint, with elements of type @code{gdb.BreakpointLocation}
Simon> +(described below).  This functionality matches that of the
Simon> +@code{info breakpoint} command (@pxref{Set Breaks}), in that it only retrieves
Simon> +the most current list of locations, thus the list itself when returned is
Simon> +not updated behind the scenes.  This attribute is not writable.
Simon> +@end defvar

I used this patch for some work I'm doing and I found this description a
bit hard to follow.  Maybe the "This functionality..."  sentence could
be replaced with one that just says "This does not cause gdb to update
the underlying list of locations"?

Simon> +@defvar BreakpointLocation.source
Simon> +This attribute returns the source file path and line number where this location
Simon> +was set. The type of the attribute is a tuple of @var{string} and
Simon> +@var{long}.  If the breakpoint location doesn't have a source location,

I think nowadays there is only 'int' in Python.

This occurs a bit later in the text as well.

Simon> +/* Python function to get the breakpoint locations of an owner breakpoint.  */
Simon> +
Simon> +static PyObject*

Space before "*".

Simon> +static PyObject *
Simon> +bplocpy_get_source_location (PyObject *py_self, void *closure)
Simon> +{
[...]
Simon> +      auto line = gdb_py_object_from_ulongest (self->bp_loc->line_number);

I think a null check is needed here.

Simon> +static PyObject *
Simon> +bplocpy_get_thread_groups (PyObject *py_self, void *closure)
[...]
Simon> +	if (PyList_Append (list.get (),
Simon> +	    gdb_py_object_from_ulongest(inf->num).release()) != 0)
Simon> +	  return nullptr;

The formatting looks weird here, but also gdb_py_object_from_ulongest
has to be called separately and the result checked for nullptr.
Note there's also a missing space before the "(".

Simon> diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
Simon> index d947b96033b..7c4648e6042 100644
Simon> --- a/gdb/python/python-internal.h
Simon> +++ b/gdb/python/python-internal.h
Simon> @@ -322,12 +322,10 @@ struct gdbpy_breakpoint_object
Simon>  	}                                                               \
Simon>      } while (0)
 
Simon> -
Simon>  /* Variables used to pass information between the Breakpoint
Simon>     constructor and the breakpoint-created hook function.  */
Simon>  extern gdbpy_breakpoint_object *bppy_pending_object;
 
Simon> -
Simon>  struct thread_object
Simon>  {
Simon>    PyObject_HEAD

This seems like a spurious change.

Simon> +   Copyright 2022-2022 Free Software Foundation, Inc.

Don't need a range here.

Simon> --- /dev/null
Simon> +++ b/gdb/testsuite/gdb.python/py-bp-locations.exp
Simon> @@ -0,0 +1,64 @@
Simon> +# Copyright (C) 2022-2022 Free Software Foundation, Inc.

Here either.

thanks,
Tom

Re: [PATCH v7] gdb/python: Add BreakpointLocation type

[Tom Tromey via Gdb-patches]

Simon> +static int find_loc_num_by_location (bp_location* loc);

Tom> I think it would be better to rearrange this so that the forward
Tom> declaration isn't needed.

[...]

I have been wanting this patch for a project I'm working on, and so I
went ahead and made the minor code tweaks needed -- a few formatting
fixups and a couple of missing Python error checks.

I didn't change the documentation, since I feel that may require some
discussion first.

I'm going to check it in now.  Thank you for doing this.

Tom