SF bug #442520: test_struct fails on SPARC.

tim-one · tim-one · commit 3dac55929910 · 2001-07-18T20:47:31.000Z
The ob_sval member of a string object isn't necessarily aligned to better
than a native long, so the new "q" and "Q" struct codes can't get away w/
casting tricks on platforms where LONG_LONG requires stricter-than-long
alignment.  After I thought of a few elaborate workarounds, Guido bashed
me over the head with the obvious memcpy approach, herewith implemented.
diff --git a/Modules/structmodule.c b/Modules/structmodule.c
@@ -547,13 +547,19 @@ nu_ulong(const char *p, const formatdef *f)
 static PyObject *
 nu_longlong(const char *p, const formatdef *f)
 {
-	return PyLong_FromLongLong(*(LONG_LONG *)p);
+	/* p may not be properly aligned */
+	LONG_LONG x;
+	memcpy(&x, p, sizeof(LONG_LONG));
+	return PyLong_FromLongLong(x);
 }
 
 static PyObject *
 nu_ulonglong(const char *p, const formatdef *f)
 {
-	return PyLong_FromUnsignedLongLong(*(unsigned LONG_LONG *)p);
+	/* p may not be properly aligned */
+	unsigned LONG_LONG x;
+	memcpy(&x, p, sizeof(unsigned LONG_LONG));
+	return PyLong_FromUnsignedLongLong(x);
 }
 #endif
 
@@ -700,7 +706,7 @@ np_longlong(char *p, PyObject *v, const formatdef *f)
 	LONG_LONG x;
 	if (get_longlong(v, &x) < 0)
 		return -1;
-	* (LONG_LONG *)p = x;
+	memcpy(p, &x, sizeof(LONG_LONG));
 	return 0;
 }
 
@@ -710,7 +716,7 @@ np_ulonglong(char *p, PyObject *v, const formatdef *f)
 	unsigned LONG_LONG x;
 	if (get_ulonglong(v, &x) < 0)
 		return -1;
-	* (unsigned LONG_LONG *)p = x;
+	memcpy(p, &x, sizeof(unsigned LONG_LONG));
 	return 0;
 }
 #endif
