bpo-41064: Improve syntax error for invalid usage of '**' in f-strings (GH-25006)
diff --git a/Parser/parser.c b/Parser/parser.c
index 6efaebe..de90c87 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -18285,7 +18285,7 @@ invalid_for_target_rule(Parser *p)
return _res;
}
-// invalid_group: '(' starred_expression ')'
+// invalid_group: '(' starred_expression ')' | '(' '**' expression ')'
static void *
invalid_group_rule(Parser *p)
{
@@ -18326,6 +18326,39 @@ invalid_group_rule(Parser *p)
D(fprintf(stderr, "%*c%s invalid_group[%d-%d]: %s failed!\n", p->level, ' ',
p->error_indicator ? "ERROR!" : "-", _mark, p->mark, "'(' starred_expression ')'"));
}
+ { // '(' '**' expression ')'
+ if (p->error_indicator) {
+ D(p->level--);
+ return NULL;
+ }
+ D(fprintf(stderr, "%*c> invalid_group[%d-%d]: %s\n", p->level, ' ', _mark, p->mark, "'(' '**' expression ')'"));
+ Token * _literal;
+ Token * _literal_1;
+ Token * a;
+ expr_ty expression_var;
+ if (
+ (_literal = _PyPegen_expect_token(p, 7)) // token='('
+ &&
+ (a = _PyPegen_expect_token(p, 35)) // token='**'
+ &&
+ (expression_var = expression_rule(p)) // expression
+ &&
+ (_literal_1 = _PyPegen_expect_token(p, 8)) // token=')'
+ )
+ {
+ D(fprintf(stderr, "%*c+ invalid_group[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "'(' '**' expression ')'"));
+ _res = RAISE_SYNTAX_ERROR_KNOWN_LOCATION ( a , "can't use double starred expression here" );
+ if (_res == NULL && PyErr_Occurred()) {
+ p->error_indicator = 1;
+ D(p->level--);
+ return NULL;
+ }
+ goto done;
+ }
+ p->mark = _mark;
+ D(fprintf(stderr, "%*c%s invalid_group[%d-%d]: %s failed!\n", p->level, ' ',
+ p->error_indicator ? "ERROR!" : "-", _mark, p->mark, "'(' '**' expression ')'"));
+ }
_res = NULL;
done:
D(p->level--);