Empty sub-expressions are normally caught as syntax error
in most expressions but this is not the case for parenthesized
expressions.
Fix this by adding a check at the end of parens_expressions()
and warning if needed.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
expression.c | 6 ++++++
validation/empty-expr.c | 27 +++++++++++++++++++++++++++
2 files changed, 33 insertions(+)
create mode 100644 validation/empty-expr.c
diff --git a/expression.c b/expression.c
index e5ebad65b..6f4300b9a 100644
--- a/expression.c
+++ b/expression.c
@@ -62,7 +62,10 @@ static struct token *comma_expression(struct token *, struct expression **);
struct token *parens_expression(struct token *token, struct expression **expr, const char *where)
{
+ struct token *p;
+
token = expect(token, '(', where);
+ p = token;
if (match_op(token, '{')) {
struct expression *e = alloc_expression(token->pos, EXPR_STATEMENT);
struct statement *stmt = alloc_statement(token->pos, STMT_COMPOUND);
@@ -74,6 +77,9 @@ struct token *parens_expression(struct token *token, struct expression **expr, c
token = expect(token, '}', "at end of statement expression");
} else
token = parse_expression(token, expr);
+
+ if (token == p)
+ sparse_error(token->pos, "an expression is expected before ')'");
return expect(token, ')', where);
}
diff --git a/validation/empty-expr.c b/validation/empty-expr.c
new file mode 100644
index 000000000..506cfba7e
--- /dev/null
+++ b/validation/empty-expr.c
@@ -0,0 +1,27 @@
+static int foo(void)
+{
+ switch () {
+ case 0:
+ return 0;
+ default:
+ return 1;
+ }
+}
+
+static int bar(void)
+{
+ if ()
+ return 0;
+ else
+ return 1;
+}
+
+/*
+ * check-name: empty expression
+ * check-known-to-fail
+ *
+ * check-error-start
+empty-expr.c:3:17: error: an expression is expected before ')'
+empty-expr.c:13:13: error: an expression is expected before ')'
+ * check-error-end
+ */
--
2.15.0
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