Don't use gdb_py_long_from_ulongest

Remove the gdb_py_long_from_ulongest defines and change the Python
layer to prefer gdb_py_object_from_ulongest.  While writing this I
noticed that the error handling in archpy_disassemble was incorrect --
it could call PyDict_SetItemString with a NULL value.  This patch also
fixes this bug.

gdb/ChangeLog
2020-09-15  Tom Tromey  <tromey@adacore.com>

	* python/python-internal.h (gdb_py_long_from_ulongest): Remove
	defines.
	* python/py-value.c (valpy_long): Use
	gdb_py_object_from_ulongest.
	* python/py-symtab.c (salpy_get_pc): Use
	gdb_py_object_from_ulongest.
	(salpy_get_last): Likewise.
	* python/py-record-btrace.c (recpy_bt_insn_pc): Use
	gdb_py_object_from_ulongest.
	* python/py-lazy-string.c (stpy_get_address): Use
	gdb_py_object_from_ulongest.
	* python/py-frame.c (frapy_pc): Use gdb_py_object_from_ulongest.
	* python/py-arch.c (archpy_disassemble): Use
	gdb_py_object_from_ulongest and gdb_py_object_from_longest.  Fix
	error handling.

1 files changed, 17 insertions, 8 deletions

diff --git a/gdb/python/py-arch.c b/gdb/python/py-arch.c
index d9eaf81..3f8e769 100644
--- a/gdb/python/py-arch.c
+++ b/gdb/python/py-arch.c
@@ -209,14 +209,23 @@ archpy_disassemble (PyObject *self, PyObject *args, PyObject *kw)
 	  return NULL;
         }
 
-      if (PyDict_SetItemString (insn_dict.get (), "addr",
-                                gdb_py_long_from_ulongest (pc))
-          || PyDict_SetItemString (insn_dict.get (), "asm",
-                                   PyString_FromString (!stb.empty ()
-							? stb.c_str ()
-							: "<unknown>"))
-          || PyDict_SetItemString (insn_dict.get (), "length",
-                                   PyInt_FromLong (insn_len)))
+      gdbpy_ref<> pc_obj = gdb_py_object_from_ulongest (pc);
+      if (pc_obj == nullptr)
+	return nullptr;
+
+      gdbpy_ref<> asm_obj (PyString_FromString (!stb.empty ()
+						? stb.c_str ()
+						: "<unknown>"));
+      if (asm_obj == nullptr)
+	return nullptr;
+
+      gdbpy_ref<> len_obj = gdb_py_object_from_longest (insn_len);
+      if (len_obj == nullptr)
+	return nullptr;
+
+      if (PyDict_SetItemString (insn_dict.get (), "addr", pc_obj.get ())
+          || PyDict_SetItemString (insn_dict.get (), "asm", asm_obj.get ())
+          || PyDict_SetItemString (insn_dict.get (), "length", len_obj.get ()))
 	return NULL;
 
       pc += insn_len;