Hi!
Compilation of the following testcase hangs forever after emitting first
error. The problem is that in one place we just return error_mark_node
directly rather than going through c_expr_sizeof_expr or c_expr_sizeof_type.
The parsing of the expression could have called record_maybe_used_decl
though, but nothing calls pop_maybe_used which needs to be called after
parsing of every sizeof/typeof, successful or not.
At the end of the toplevel declaration we free the parser_obstack and in
another function record_maybe_used_decl is called again and due to the
missing pop_maybe_unused we end up with a cycle in the chain.
The following patch fixes it by just setting error and goto to the
sizeof_expr:
c_inhibit_evaluation_warnings--;
in_sizeof--;
mark_exp_read (expr.value);
if (TREE_CODE (expr.value) == COMPONENT_REF
&& DECL_C_BIT_FIELD (TREE_OPERAND (expr.value, 1)))
error_at (expr_loc, "%<sizeof%> applied to a bit-field");
result = c_expr_sizeof_expr (expr_loc, expr);
where c_expr_sizeof_expr will do:
struct c_expr ret;
if (expr.value == error_mark_node)
{
ret.value = error_mark_node;
ret.original_code = ERROR_MARK;
ret.original_type = NULL;
ret.m_decimal = 0;
pop_maybe_used (false);
}
...
return ret;
which is exactly what the old code did manually except for the missing
pop_maybe_used call. mark_exp_read does nothing on error_mark_node and
error_mark_node doesn't have COMPONENT_REF tree_code.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2024-11-27 Jakub Jelinek <ja...@redhat.com>
PR c/117745
* c-parser.cc (c_parser_sizeof_expression): If type_name is NULL,
just expr.set_error () and goto sizeof_expr instead of doing error
recovery manually.
* gcc.dg/pr117745.c: New test.
--- gcc/c/c-parser.cc.jj 2024-11-23 13:00:28.328028242 +0100
+++ gcc/c/c-parser.cc 2024-11-26 11:59:18.036410746 +0100
@@ -10405,13 +10405,8 @@ c_parser_sizeof_expression (c_parser *pa
finish = parser->tokens_buf[0].location;
if (type_name == NULL)
{
- struct c_expr ret;
- c_inhibit_evaluation_warnings--;
- in_sizeof--;
- ret.set_error ();
- ret.original_code = ERROR_MARK;
- ret.original_type = NULL;
- return ret;
+ expr.set_error ();
+ goto sizeof_expr;
}
if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
{
--- gcc/testsuite/gcc.dg/pr117745.c.jj 2024-11-26 12:07:11.120756946 +0100
+++ gcc/testsuite/gcc.dg/pr117745.c 2024-11-26 12:08:00.031068850 +0100
@@ -0,0 +1,8 @@
+/* PR c/117745 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+static int foo (void);
+void bar (void) { sizeof (int [0 ? foo () : 1); } /* { dg-error
"expected" } */
+static int baz (void);
+void qux (void) { sizeof (sizeof (int[baz ()])); }
Jakub
