py/parse: Remove unnecessary check in const folding for ** operator.

dpgeorge · dpgeorge · commit 4914731e5831 · 2020-04-09T16:02:39.000+10:00
In this part of the code there is no way to get the ** operator, so no need
to check for it.

This commit also adds tests for this, and other related, invalid const
operations.
diff --git a/py/parse.c b/py/parse.c
@@ -655,8 +655,8 @@ STATIC bool fold_constants(parser_t *parser, uint8_t rule_id, size_t num_args) {
                 return false;
             }
             mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, i));
-            if (tok == MP_TOKEN_OP_AT || tok == MP_TOKEN_OP_SLASH || tok == MP_TOKEN_OP_DBL_STAR) {
-                // Can't fold @ or / or **
+            if (tok == MP_TOKEN_OP_AT || tok == MP_TOKEN_OP_SLASH) {
+                // Can't fold @ or /
                 return false;
             }
             mp_binary_op_t op = MP_BINARY_OP_LSHIFT + (tok - MP_TOKEN_OP_DBL_LESS);
diff --git a/tests/micropython/const_error.py b/tests/micropython/const_error.py
@@ -15,3 +15,12 @@ def test_syntax(code):
 
 # redefined constant
 test_syntax("A = const(1); A = const(2)")
+
+# these operations are not supported within const
+test_syntax("A = const(1 @ 2)")
+test_syntax("A = const(1 / 2)")
+test_syntax("A = const(1 ** 2)")
+test_syntax("A = const(1 << -2)")
+test_syntax("A = const(1 >> -2)")
+test_syntax("A = const(1 % 0)")
+test_syntax("A = const(1 // 0)")
diff --git a/tests/micropython/const_error.py.exp b/tests/micropython/const_error.py.exp
@@ -1,2 +1,9 @@
 SyntaxError
 SyntaxError
+SyntaxError
+SyntaxError
+SyntaxError
+SyntaxError
+SyntaxError
+SyntaxError
+SyntaxError

Original file line number	Diff line number	Diff line change
`@@ -655,8 +655,8 @@ STATIC bool fold_constants(parser_t *parser, uint8_t rule_id, size_t num_args) {`
`655`	`655`	`return false;`
`656`	`656`	`}`
`657`	`657`	`mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, i));`
`658`		`- if (tok == MP_TOKEN_OP_AT \|\| tok == MP_TOKEN_OP_SLASH \|\| tok == MP_TOKEN_OP_DBL_STAR) {`
`659`		`- // Can't fold @ or / or **`
	`658`	`+ if (tok == MP_TOKEN_OP_AT \|\| tok == MP_TOKEN_OP_SLASH) {`
	`659`	`+ // Can't fold @ or /`
`660`	`660`	`return false;`
`661`	`661`	`}`
`662`	`662`	`mp_binary_op_t op = MP_BINARY_OP_LSHIFT + (tok - MP_TOKEN_OP_DBL_LESS);`