bpo-31338 (#3374)

* Add Py_UNREACHABLE() as an alias to abort().
* Use Py_UNREACHABLE() instead of assert(0)
* Convert more unreachable code to use Py_UNREACHABLE()
* Document Py_UNREACHABLE() and a few other macros.

1 files changed, 3 insertions, 4 deletions

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 4862b76da6..3b07585669 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -1806,8 +1806,7 @@ long_format_binary(PyObject *aa, int base, int alternate,
         bits = 1;
         break;
     default:
-        assert(0); /* shouldn't ever get here */
-        bits = 0; /* to silence gcc warning */
+        Py_UNREACHABLE();
     }
 
     /* Compute exact length 'sz' of output string. */
@@ -2169,8 +2168,8 @@ PyLong_FromString(const char *str, char **pend, int base)
         }
     }
     if (str[0] == '_') {
-	    /* May not start with underscores. */
-	    goto onError;
+        /* May not start with underscores. */
+        goto onError;
     }
 
     start = str;