mypyc: ignore deprecation (#9107)

PyUnicode_AsUnicodeAndSize has been deprecated since 3.3

Python 3.9 has compiler warnings for this deprecated function, and we
compile with Werror, causing Python 3.9 builds to fail.

I've just copied over the relevant deprecation ignoring code from the
original getargs.c (including the TODO, but I can remove that)

Co-authored-by: hauntsaninja <>

mypyc/lib-rt/getargs.c

@@ -18,6 +18,29 @@
  *    and is responsible for decrefing them.
  */
 
+// These macro definitions are copied from pyport.h in Python 3.9 and later
+// https://bugs.python.org/issue19569
+#if defined(__clang__)
+#define _Py_COMP_DIAG_PUSH _Pragma("clang diagnostic push")
+#define _Py_COMP_DIAG_IGNORE_DEPR_DECLS \
+    _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")
+#define _Py_COMP_DIAG_POP _Pragma("clang diagnostic pop")
+#elif defined(__GNUC__) \
+    && ((__GNUC__ >= 5) || (__GNUC__ == 4) && (__GNUC_MINOR__ >= 6))
+#define _Py_COMP_DIAG_PUSH _Pragma("GCC diagnostic push")
+#define _Py_COMP_DIAG_IGNORE_DEPR_DECLS \
+    _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
+#define _Py_COMP_DIAG_POP _Pragma("GCC diagnostic pop")
+#elif defined(_MSC_VER)
+#define _Py_COMP_DIAG_PUSH __pragma(warning(push))
+#define _Py_COMP_DIAG_IGNORE_DEPR_DECLS __pragma(warning(disable: 4996))
+#define _Py_COMP_DIAG_POP __pragma(warning(pop))
+#else
+#define _Py_COMP_DIAG_PUSH
+#define _Py_COMP_DIAG_IGNORE_DEPR_DECLS
+#define _Py_COMP_DIAG_POP
+#endif
+
 #include "Python.h"
 #include "pythonsupport.h"
 
@@ -756,6 +779,9 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
     case 'u': /* raw unicode buffer (Py_UNICODE *) */
     case 'Z': /* raw unicode buffer or None */
     {
+        // TODO: Raise DeprecationWarning
+_Py_COMP_DIAG_PUSH
+_Py_COMP_DIAG_IGNORE_DEPR_DECLS
         Py_UNICODE **p = va_arg(*p_va, Py_UNICODE **);
 
         if (*format == '#') {
@@ -795,6 +821,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
                                   arg, msgbuf, bufsize);
         }
         break;
+_Py_COMP_DIAG_POP
     }
 
     case 'e': {/* encoded string */