gdb/python: hoist common invalid object repr code into py-utils.c

Many object types now have a __repr__() function implementation.  A
common pattern is that, if an object is invalid, we print its
representation as: <TYPENAME (invalid)>.

I thought it might be a good idea to move the formatting of this
specific representation into a utility function, and then update all
of our existing code to call the new function.

The only place where I haven't made use of the new function is in
unwind_infopy_repr, where we currently return a different string.
This case is a little different as the UnwindInfo is invalid because
it references a frame, and it is the frame itself which is invalid.
That said, I think it would be fine to switch to using the standard
format; if the UnwindInfo references an invalid frame, then the
UnwindInfo is itself invalid.  But changing this would be an actual
change in behaviour, while all the other changes in this commit are
just refactoring.

Approved-By: Tom Tromey <tom@tromey.com>

11 files changed, 27 insertions, 11 deletions

diff --git a/gdb/python/py-arch.c b/gdb/python/py-arch.c
index ac51933..b7d861d 100644
--- a/gdb/python/py-arch.c
+++ b/gdb/python/py-arch.c
@@ -326,7 +326,7 @@ archpy_repr (PyObject *self)
 {
   const auto gdbarch = arch_object_to_gdbarch (self);
   if (gdbarch == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+    return gdb_py_invalid_object_repr (self);
 
   auto arch_info = gdbarch_bfd_arch_info (gdbarch);
   return PyUnicode_FromFormat ("<%s arch_name=%s printable_name=%s>",
diff --git a/gdb/python/py-block.c b/gdb/python/py-block.c
index dd6d6d2..34be466 100644
--- a/gdb/python/py-block.c
+++ b/gdb/python/py-block.c
@@ -425,7 +425,7 @@ blpy_repr (PyObject *self)
 {
   const auto block = block_object_to_block (self);
   if (block == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+    return gdb_py_invalid_object_repr (self);
 
   const auto name = block->function () ?
     block->function ()->print_name () : "<anonymous>";
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 5155d41..9b5e023 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -1750,8 +1750,8 @@ bplocpy_repr (PyObject *py_self)
 {
   const auto self = (gdbpy_breakpoint_location_object *) py_self;
   if (self->owner == nullptr || self->owner->bp == nullptr
-    || self->owner->bp != self->bp_loc->owner)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+      || self->owner->bp != self->bp_loc->owner)
+    return gdb_py_invalid_object_repr (py_self);
 
   const auto enabled = self->bp_loc->enabled ? "enabled" : "disabled";
 
diff --git a/gdb/python/py-connection.c b/gdb/python/py-connection.c
index 3df12b4..d288a74 100644
--- a/gdb/python/py-connection.c
+++ b/gdb/python/py-connection.c
@@ -204,7 +204,7 @@ connpy_repr (PyObject *obj)
   process_stratum_target *target = self->target;
 
   if (target == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (obj)->tp_name);
+    return gdb_py_invalid_object_repr (obj);
 
   return PyUnicode_FromFormat ("<%s num=%d, what=\"%s\">",
 			       Py_TYPE (obj)->tp_name,
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index ed153d6..929d8bd 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -800,7 +800,7 @@ infpy_repr (PyObject *obj)
   inferior *inf = self->inferior;
 
   if (inf == nullptr)
-    return PyUnicode_FromString ("<gdb.Inferior (invalid)>");
+    return gdb_py_invalid_object_repr (obj);
 
   return PyUnicode_FromFormat ("<gdb.Inferior num=%d, pid=%d>",
 			       inf->num, inf->pid);
diff --git a/gdb/python/py-objfile.c b/gdb/python/py-objfile.c
index bb5d0d9..4f5e5cd 100644
--- a/gdb/python/py-objfile.c
+++ b/gdb/python/py-objfile.c
@@ -537,7 +537,7 @@ objfpy_repr (PyObject *self_)
   objfile *obj = self->objfile;
 
   if (obj == nullptr)
-    return PyUnicode_FromString ("<gdb.Objfile (invalid)>");
+    return gdb_py_invalid_object_repr (self_);
 
   return PyUnicode_FromFormat ("<gdb.Objfile filename=%s>",
 			       objfile_name (obj));
diff --git a/gdb/python/py-symbol.c b/gdb/python/py-symbol.c
index 99724cf..014442b 100644
--- a/gdb/python/py-symbol.c
+++ b/gdb/python/py-symbol.c
@@ -385,7 +385,7 @@ sympy_repr (PyObject *self)
 {
   const auto symbol = symbol_object_to_symbol (self);
   if (symbol == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+    return gdb_py_invalid_object_repr (self);
 
   return PyUnicode_FromFormat ("<%s print_name=%s>", Py_TYPE (self)->tp_name,
 			       symbol->print_name ());
diff --git a/gdb/python/py-type.c b/gdb/python/py-type.c
index bfaa6d2..27c7b78 100644
--- a/gdb/python/py-type.c
+++ b/gdb/python/py-type.c
@@ -1083,8 +1083,7 @@ typy_repr (PyObject *self)
 {
   const auto type = type_object_to_type (self);
   if (type == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>",
-				 Py_TYPE (self)->tp_name);
+    return gdb_py_invalid_object_repr (self);
 
   const char *code = pyty_codes[type->code ()].name;
   string_file type_name;
diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index f12485c..70c3372 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -425,7 +425,7 @@ pending_framepy_repr (PyObject *self)
   frame_info_ptr frame = pending_frame->frame_info;
 
   if (frame == nullptr)
-    return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+    return gdb_py_invalid_object_repr (self);
 
   const char *sp_str = nullptr;
   const char *pc_str = nullptr;
diff --git a/gdb/python/py-utils.c b/gdb/python/py-utils.c
index f1ca9ea..c292910 100644
--- a/gdb/python/py-utils.c
+++ b/gdb/python/py-utils.c
@@ -597,3 +597,11 @@ gdbpy_fix_doc_string_indentation (gdb::unique_xmalloc_ptr<char> doc)
 
   return doc;
 }
+
+/* See python-internal.h.  */
+
+PyObject *
+gdb_py_invalid_object_repr (PyObject *self)
+{
+  return PyUnicode_FromFormat ("<%s (invalid)>", Py_TYPE (self)->tp_name);
+}
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 14e1557..8ff9af6 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -897,6 +897,15 @@ int gdb_pymodule_addobject (PyObject *module, const char *name,
 			    PyObject *object)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 
+
+/* Return a Python string (str) object that represents SELF.  SELF can be
+   any object type, but should be in an "invalid" state.  What "invalid"
+   means is up to the caller.  The returned string will take the form
+   "<TYPENAME (invalid)>", without the quotes, and with TYPENAME replaced
+   with the type of SELF.  */
+
+PyObject *gdb_py_invalid_object_repr (PyObject *self);
+
 struct varobj_iter;
 struct varobj;
 std::unique_ptr<varobj_iter> py_varobj_get_iterator