N2253 allowed referring to non-static data members without an object in
unevaluated operands like that of sizeof, but in a constant-expression
context like an array bound or template argument within such an unevaluated
operand we do actually need a value, so that permission cannot apply.
Tested x86_64-pc-linux-gnu, applying to trunk.
gcc/cp/ChangeLog:
PR c++/93314
* semantics.c (finish_id_expression_1): Clear cp_unevaluated_operand
for a non-static data member in a constant-expression.
gcc/testsuite/ChangeLog:
PR c++/93314
* g++.dg/parse/uneval1.C: New test.
---
gcc/cp/semantics.c | 10 ++++++++++
gcc/testsuite/g++.dg/parse/uneval1.C | 14 ++++++++++++++
2 files changed, 24 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/parse/uneval1.C
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 125772238d3..4520181d4e5 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -4093,6 +4093,12 @@ finish_id_expression_1 (tree id_expression,
cp_warn_deprecated_use_scopes (scope);
+ /* In a constant-expression context, turn off cp_unevaluated_operand
+ so finish_non_static_data_member will complain (93314). */
+ auto eval = make_temp_override (cp_unevaluated_operand);
+ if (integral_constant_expression_p && TREE_CODE (decl) == FIELD_DECL)
+ cp_unevaluated_operand = 0;
+
if (TYPE_P (scope))
decl = finish_qualified_id_expr (scope,
decl,
@@ -4106,6 +4112,10 @@ finish_id_expression_1 (tree id_expression,
}
else if (TREE_CODE (decl) == FIELD_DECL)
{
+ auto eval = make_temp_override (cp_unevaluated_operand);
+ if (integral_constant_expression_p)
+ cp_unevaluated_operand = 0;
+
/* Since SCOPE is NULL here, this is an unqualified name.
Access checking has been performed during name lookup
already. Turn off checking to avoid duplicate errors. */
diff --git a/gcc/testsuite/g++.dg/parse/uneval1.C
b/gcc/testsuite/g++.dg/parse/uneval1.C
new file mode 100644
index 00000000000..dfc1bb4e0c3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/uneval1.C
@@ -0,0 +1,14 @@
+// PR c++/93314
+
+struct S {
+ int m;
+ static int f() {
+ return sizeof(char[m]); // { dg-error "S::m" }
+ }
+};
+
+int main()
+{
+ return S().f()
+ + sizeof(char[S::m]); // { dg-error "S::m" }
+}
base-commit: f99f64f69db49ce6343d79a39eab28dcc6b91865
--
2.27.0
