Re: [patch] [python] PR python/15461 (gate architecture calls)

Phil Muldoon
2013-08-29T11:15:09Z

On 28/08/13 16:54, Tom Tromey wrote:
> Phil> I don't disagree on the efficiency argument, but my goal here was to
> Phil> follow the pattern that other objects use to determine validity of the
> Phil> underlying GDB data. To bring a sense of uniformity to how we do
> Phil> things in Python. So how we check a gdb.Frame's, et al, validity, the
> Phil> pattern will be the same, as far as possible, for other objects.
>
> Ok.
>
> If you look at other ones, they set the Python exception. At least that
> is true for py-block.c (twice), py-inferior.c, py-inthread.c,
> py-symbol.c, py-symtab.c (twice), etc.
>
> FWIW I don't mind inconsistency in these little details. What matters
> is the context in which the macro is most useful.

For some reason I totally misread your original comment. I re-read
the thread this morning, and found my mistake. Mea Cupla. I thought
you did not want the macro, but that was not the case. Your objection
was to the error() call, and was totally correct. Not sure why I read
that email so incorrectly. Apologies.

So just ignore my previous comments ;)

Updated the patch. ChangeLog remains the same.

Cheers,

Phil

--

diff --git a/gdb/python/py-arch.c b/gdb/python/py-arch.c
index 7098a8a..a31ffdd 100644
--- a/gdb/python/py-arch.c
+++ b/gdb/python/py-arch.c
@@ -30,6 +30,18 @@ typedef struct arch_object_type_object {

static struct gdbarch_data *arch_object_data = NULL;

+/* Require a valid Architecture. */
+#define ARCHPY_REQUIRE_VALID(arch_obj, arch) \
+ do { \
+ arch = arch_object_to_gdbarch (arch_obj); \
+ if (arch == NULL) \
+ { \
+ PyErr_SetString (PyExc_RuntimeError, \
+ _("Architecture is invalid.")); \
+ return NULL; \
+ } \
+ } while (0)
+
static PyTypeObject arch_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("arch_object");

@@ -82,9 +94,14 @@ gdbarch_to_arch_object (struct gdbarch *gdbarch)
static PyObject *
archpy_name (PyObject *self, PyObject *args)
{
- struct gdbarch *gdbarch = arch_object_to_gdbarch (self);
- const char *name = (gdbarch_bfd_arch_info (gdbarch))->printable_name;
- PyObject *py_name = PyString_FromString (name);
+ struct gdbarch *gdbarch = NULL;
+ const char *name;
+ PyObject *py_name;
+
+ ARCHPY_REQUIRE_VALID (self, gdbarch);
+
+ name = (gdbarch_bfd_arch_info (gdbarch))->printable_name;
+ py_name = PyString_FromString (name);

return py_name;
}
@@ -104,7 +121,9 @@ archpy_disassemble (PyObject *self, PyObject *args, PyObject *kw)
gdb_py_ulongest start_temp;
long count = 0, i;
PyObject *result_list, *end_obj = NULL, *count_obj = NULL;
- struct gdbarch *gdbarch = arch_object_to_gdbarch (self);
+ struct gdbarch *gdbarch = NULL;
+
+ ARCHPY_REQUIRE_VALID (self, gdbarch);

if (!PyArg_ParseTupleAndKeywords (args, kw, GDB_PY_LLU_ARG "|OO", keywords,
&start_temp, &end_obj, &count_obj))
diff --git a/gdb/testsuite/gdb.python/py-arch.exp b/gdb/testsuite/gdb.python/py-arch.exp
index 4e736b8..6fff256 100644
--- a/gdb/testsuite/gdb.python/py-arch.exp
+++ b/gdb/testsuite/gdb.python/py-arch.exp
@@ -26,6 +26,14 @@ if ![runto_main] {
return -1
}

+# Test python/15461. Invalid architectures should not trigger an
+# internal GDB assert.
+gdb_py_test_silent_cmd "python empty = gdb.Architecture()" "get empty arch" 0
+gdb_test "python print(empty.name())" ".*Architecture is invalid.*" \
+ "Test empty architecture.name does not trigger an assert"
+gdb_test "python print(empty.disassemble())" ".*Architecture is invalid.*" \
+ "Test empty architecture.disassemble does not trigger an assert"
+
gdb_py_test_silent_cmd "python frame = gdb.selected_frame()" "get frame" 0
gdb_py_test_silent_cmd "python arch = frame.architecture()" "get arch" 0
gdb_py_test_silent_cmd "python pc = frame.pc()" "get pc" 0