[PATCH 2/3] python: Add Progspace.objfiles method

[Simon Marchi <simon.marchi@ericsson.com>]

This patch adds an objfiles method, which returns a sequence of the
objfiles associated to that program space.  I chose a method rather than
a property for symmetry with gdb.objfiles().

Question:

When we try to access a property of an Inferior object that has
become invalid, for example, we raise an exception ("Inferior no longer
exists.").  When doing the same with a Progspace object, we return None
(the only case for now is its filename property).  For
Progspace.objfiles(), I made it return None too, but perhaps it should
throw an exception instead?  Especially that None is not iterable, so
trying to do:

  for obj in pspace.objfiles():
    ...

will fail horribly if we return None...  so should I introduce a macro
similar to INFPY_REQUIRE_VALID?

gdb/ChangeLog:

	* python/py-progspace.c (pspy_get_objfiles): New function.
	(progspace_object_methods): New.
	(pspace_object_type): Add tp_methods callback.
	* python/python-internal.h (build_objfiles_list): New
	declaration.
	* python/python.c (build_objfiles_list): New function.
	(gdbpy_objfiles): Implement using build_objfiles_list.
	* NEWS: Mention the Progspace.objfiles method.

gdb/doc/ChangeLog:

	* python.texi (Program Spaces In Python): Document the
	Progspace.objfiles method.

gdb/testsuite/ChangeLog:

	* gdb.python/py-progspace.exp: Test the Progspace.objfiles
	method.
---
 gdb/NEWS                                  |  3 +++
 gdb/doc/python.texi                       |  6 +++++
 gdb/python/py-progspace.c                 | 23 +++++++++++++++--
 gdb/python/python-internal.h              |  4 +++
 gdb/python/python.c                       | 28 +++++++++++++--------
 gdb/testsuite/gdb.python/py-progspace.exp | 30 +++++++++++++++++++++++
 6 files changed, 82 insertions(+), 12 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index 21da6ae4ba8..f4d281eef0e 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -89,6 +89,9 @@ CSKY GNU/LINUX			csky*-*-linux
   ** The program space associated to an inferior is now accessible through a
      new "progspace" attribute of gdb.Inferior.
 
+  ** The gdb.Progspace type has a new objfiles method, which returns the list
+     of objfiles associated to that program space.
+
 *** Changes in GDB 8.2
 
 * The 'set disassembler-options' command now supports specifying options
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index d4f03439f10..abda135e17d 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -4073,6 +4073,12 @@ Hello.
 [Inferior 1 (process 4242) exited normally]
 @end smallexample
 
+A @code{gdb.Progspace} object has the following methods:
+
+@defun Progspace.objfiles ()
+Return a sequence of all the objfiles associated to this program space (@pxref{Objfiles In Python}).
+@end defun
+
 @node Objfiles In Python
 @subsubsection Objfiles In Python
 
diff --git a/gdb/python/py-progspace.c b/gdb/python/py-progspace.c
index 3eaa466666d..64587ab16aa 100644
--- a/gdb/python/py-progspace.c
+++ b/gdb/python/py-progspace.c
@@ -314,7 +314,19 @@ pspy_set_type_printers (PyObject *o, PyObject *value, void *ignore)
   return 0;
 }
 
-\f
+/* Implement the objfiles method.  */
+
+PyObject *
+pspy_get_objfiles (PyObject *o, PyObject *unused2)
+{
+  pspace_object *self = (pspace_object *) o;
+
+  program_space *pspace = self->pspace;
+  if (pspace == nullptr)
+    Py_RETURN_NONE;
+
+  return build_objfiles_list (pspace).release ();
+}
 
 /* Clear the PSPACE pointer in a Pspace object and remove the reference.  */
 
@@ -397,6 +409,13 @@ static gdb_PyGetSetDef pspace_getset[] =
   { NULL }
 };
 
+static PyMethodDef progspace_object_methods[] =
+{
+  { "objfiles", pspy_get_objfiles, METH_NOARGS,
+    "Return a sequence of objfiles associated to this program space." },
+  { NULL }
+};
+
 PyTypeObject pspace_object_type =
 {
   PyVarObject_HEAD_INIT (NULL, 0)
@@ -426,7 +445,7 @@ PyTypeObject pspace_object_type =
   0,				  /* tp_weaklistoffset */
   0,				  /* tp_iter */
   0,				  /* tp_iternext */
-  0,				  /* tp_methods */
+  progspace_object_methods,	  /* tp_methods */
   0,				  /* tp_members */
   pspace_getset,		  /* tp_getset */
   0,				  /* tp_base */
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 3874fdc5e79..785ad171511 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -549,6 +549,10 @@ struct symtab_and_line *sal_object_to_symtab_and_line (PyObject *obj);
 struct frame_info *frame_object_to_frame_info (PyObject *frame_obj);
 struct gdbarch *arch_object_to_gdbarch (PyObject *obj);
 
+/* Return a Python list containing an Objfile object for each objfile in
+   PSPACE.  */
+gdbpy_ref<> build_objfiles_list (program_space *pspace);
+
 void gdbpy_initialize_gdb_readline (void);
 int gdbpy_initialize_auto_load (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 6f798a0e461..371f4a57529 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1437,10 +1437,10 @@ gdbpy_get_current_objfile (PyObject *unused1, PyObject *unused2)
   return result;
 }
 
-/* Return a sequence holding all the Objfiles.  */
+/* See python-internal.h.  */
 
-static PyObject *
-gdbpy_objfiles (PyObject *unused1, PyObject *unused2)
+gdbpy_ref<>
+build_objfiles_list (program_space *pspace)
 {
   struct objfile *objf;
 
@@ -1448,15 +1448,23 @@ gdbpy_objfiles (PyObject *unused1, PyObject *unused2)
   if (list == NULL)
     return NULL;
 
-  ALL_OBJFILES (objf)
-  {
-    PyObject *item = objfile_to_objfile_object (objf);
+  ALL_PSPACE_OBJFILES (pspace, objf)
+    {
+      PyObject *item = objfile_to_objfile_object (objf);
 
-    if (!item || PyList_Append (list.get (), item) == -1)
-      return NULL;
-  }
+      if (item == nullptr || PyList_Append (list.get (), item) == -1)
+	return NULL;
+    }
 
-  return list.release ();
+  return list;
+}
+
+/* Return a sequence holding all the Objfiles.  */
+
+static PyObject *
+gdbpy_objfiles (PyObject *unused1, PyObject *unused2)
+{
+  return build_objfiles_list (current_program_space).release ();
 }
 
 /* Compute the list of active python type printers and store them in
diff --git a/gdb/testsuite/gdb.python/py-progspace.exp b/gdb/testsuite/gdb.python/py-progspace.exp
index f0cafa834e0..53920c16fb0 100644
--- a/gdb/testsuite/gdb.python/py-progspace.exp
+++ b/gdb/testsuite/gdb.python/py-progspace.exp
@@ -51,3 +51,33 @@ gdb_py_test_silent_cmd "python progspace.random_attribute = 42" \
     "Set random attribute in progspace" 1
 gdb_test "python print (progspace.random_attribute)" "42" \
     "Verify set of random attribute in progspace"
+
+if {![runto_main]} {
+    fail "can't run to main"
+    return
+}
+
+# With a single inferior, progspace.objfiles () and gdb.objfiles () should
+# be identical.
+gdb_test "python print (progspace.objfiles () == gdb.objfiles ())" "True"
+
+gdb_test "add-inferior"
+gdb_test "inferior 2"
+
+gdb_load ${binfile}
+
+# With a second (non-started) inferior, we should have a single objfile - the
+# main one.
+gdb_test "python print (len (gdb.objfiles ())) == 1"
+
+# And the gdb.objfiles() list should now be different from the objfiles of the
+# prog space of inferior 1.
+gdb_test "python print (progspace.objfiles () != gdb.objfiles ())" "True"
+
+# Delete inferior 2 (and therefore the second progspace), check that the Python
+# object reacts sensibly.
+gdb_py_test_silent_cmd "python progspace2 = gdb.current_progspace()" \
+    "save progspace 2" 1
+gdb_test "inferior 1" "Switching to inferior 1.*"
+gdb_test_no_output "remove-inferiors 2"
+gdb_test "python print (progspace2.objfiles ())" "None"
-- 
2.19.0