gh-133143: Add sys.abi_info (GH-137476)

This makes information about the interpreter ABI more accessible.

Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index cc798f6..95ab875 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -3268,6 +3268,7 @@ PyDoc_STR(
 "\n\
 Static objects:\n\
 \n\
+abi_info -- Python ABI information.\n\
 builtin_module_names -- tuple of module names built into this interpreter\n\
 copyright -- copyright notice pertaining to this interpreter\n\
 exec_prefix -- prefix used to find the machine-specific Python library\n\
@@ -3638,6 +3639,73 @@ error:
     return NULL;
 }
 
+
+static PyObject *
+make_abi_info(void)
+{
+    // New entries should be added when needed for a supported platform, or (for
+    // enabling an unsupported one) by core dev consensus.  Entries should be removed
+    // following PEP 387.
+    int res;
+    PyObject *abi_info, *value, *ns;
+    abi_info = PyDict_New();
+    if (abi_info == NULL) {
+        goto error;
+    }
+
+    value = PyLong_FromLong(sizeof(void *) * 8);
+    if (value == NULL) {
+        goto error;
+    }
+    res = PyDict_SetItemString(abi_info, "pointer_bits", value);
+    Py_DECREF(value);
+    if (res < 0) {
+        goto error;
+    }
+
+#ifdef Py_GIL_DISABLED
+    value = Py_True;
+#else
+    value = Py_False;
+#endif
+    res = PyDict_SetItemString(abi_info, "free_threaded", value);
+    if (res < 0) {
+        goto error;
+    }
+
+#ifdef Py_DEBUG
+    value = Py_True;
+#else
+    value = Py_False;
+#endif
+    res = PyDict_SetItemString(abi_info, "debug", value);
+    if (res < 0) {
+        goto error;
+    }
+
+#if PY_BIG_ENDIAN
+    value = PyUnicode_FromString("big");
+#else
+    value = PyUnicode_FromString("little");
+#endif
+    if (value == NULL) {
+        goto error;
+    }
+    res = PyDict_SetItemString(abi_info, "byteorder", value);
+    Py_DECREF(value);
+    if (res < 0) {
+        goto error;
+    }
+
+    ns = _PyNamespace_New(abi_info);
+    Py_DECREF(abi_info);
+    return ns;
+
+error:
+    Py_DECREF(abi_info);
+    return NULL;
+}
+
 #ifdef __EMSCRIPTEN__
 
 PyDoc_STRVAR(emscripten_info__doc__,
@@ -3863,6 +3931,8 @@ _PySys_InitCore(PyThreadState *tstate, PyObject *sysdict)
 
     SET_SYS("thread_info", PyThread_GetInfo());
 
+    SET_SYS("abi_info", make_abi_info());
+
     /* initialize asyncgen_hooks */
     if (_PyStructSequence_InitBuiltin(interp, &AsyncGenHooksType,
                                       &asyncgen_hooks_desc) < 0)