[PATCH v5 16/58] perf python: Add syscall name/id to convert syscall number and name

[Ian Rogers]

Use perf's syscalltbl support to convert syscall number to name
assuming the number is for the host machine. This avoids python
libaudit support as tools/perf/scripts/python/syscall-counts.py
requires.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers at google.com>
---
v2:

1. Guarded with HAVE_LIBTRACEEVENT : Wrapped the syscall functions and
   their entries in perf__methods with #ifdef HAVE_LIBTRACEEVENT to
   avoid potential linker errors if CONFIG_TRACE is disabled.

2. Changed Exception Type: Updated pyrf__syscall_id to raise a
   ValueError instead of a TypeError when a syscall is not found.

3. Fixed Typo: Corrected "name number" to "name" in the docstring for
   syscall_id.
---
 tools/perf/util/python.c | 44 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 35eda69a32e1..f240905e07d6 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -13,6 +13,7 @@
 #include "counts.h"
 #include "data.h"
 #include "debug.h"
+#include "dwarf-regs.h"
 #include "event.h"
 #include "evlist.h"
 #include "evsel.h"
@@ -25,6 +26,7 @@
 #include "session.h"
 #include "strbuf.h"
 #include "symbol.h"
+#include "syscalltbl.h"
 #include "thread.h"
 #include "thread_map.h"
 #include "tool.h"
@@ -2635,6 +2637,36 @@ static int pyrf_session__setup_types(void)
 	return PyType_Ready(&pyrf_session__type);
 }
 
+static PyObject *pyrf__syscall_name(PyObject *self, PyObject *args)
+{
+	const char *name;
+	int id;
+
+	if (!PyArg_ParseTuple(args, "i", &id))
+		return NULL;
+
+	name = syscalltbl__name(EM_HOST, id);
+	if (!name)
+		Py_RETURN_NONE;
+	return PyUnicode_FromString(name);
+}
+
+static PyObject *pyrf__syscall_id(PyObject *self, PyObject *args)
+{
+	const char *name;
+	int id;
+
+	if (!PyArg_ParseTuple(args, "s", &name))
+		return NULL;
+
+	id = syscalltbl__id(EM_HOST, name);
+	if (id < 0) {
+		PyErr_Format(PyExc_ValueError, "Failed to find syscall %s", name);
+		return NULL;
+	}
+	return PyLong_FromLong(id);
+}
+
 static PyMethodDef perf__methods[] = {
 	{
 		.ml_name  = "metrics",
@@ -2668,6 +2700,18 @@ static PyMethodDef perf__methods[] = {
 		.ml_flags = METH_NOARGS,
 		.ml_doc	  = PyDoc_STR("Returns a sequence of pmus.")
 	},
+	{
+		.ml_name  = "syscall_name",
+		.ml_meth  = (PyCFunction) pyrf__syscall_name,
+		.ml_flags = METH_VARARGS,
+		.ml_doc	  = PyDoc_STR("Turns a syscall number to a string.")
+	},
+	{
+		.ml_name  = "syscall_id",
+		.ml_meth  = (PyCFunction) pyrf__syscall_id,
+		.ml_flags = METH_VARARGS,
+		.ml_doc	  = PyDoc_STR("Turns a syscall name to a number.")
+	},
 	{ .ml_name = NULL, }
 };
 
-- 
2.54.0.545.g6539524ca2-goog