Add a really stupid warning about 'yield' used as an identifier.
This is really stupid because it cannot be suppressed or altered using
the warning framework; that's because the warning framework is built
on Python interpreter internals, and the parser generator doesn't have
access to any of those (you cannot use anything of type PyObject * in
the parser).
But it's better than nothing, and implementing a proper check for this
appears to require modifying compile.c in a dozen places, for which I
don't have the stamina today. I promise we'll do better in 2.2a2.
At least it tells you the filename and line number (unlike the first
hack I considered :-).
diff --git a/Parser/parsetok.c b/Parser/parsetok.c
index 6017e5f..386b82f 100644
--- a/Parser/parsetok.c
+++ b/Parser/parsetok.c
@@ -92,6 +92,9 @@
/* Parse input coming from the given tokenizer structure.
Return error code. */
+static char yield_msg[] =
+"%s:%d: Warning: 'yield' will become a reserved keyword in the future\n";
+
static node *
parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
int flags)
@@ -135,6 +138,15 @@
if (len > 0)
strncpy(str, a, len);
str[len] = '\0';
+
+ /* Warn about yield as NAME */
+ if (type == NAME && !ps->p_generators &&
+ len == 5 && str[0] == 'y' && strcmp(str, "yield") == 0)
+ PySys_WriteStderr(yield_msg,
+ err_ret->filename==NULL ?
+ "<string>" : err_ret->filename,
+ tok->lineno);
+
if ((err_ret->error =
PyParser_AddToken(ps, (int)type, str, tok->lineno,
&(err_ret->expected))) != E_OK) {