Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/16?
-- >8 --
We trip on the assert in lvalue_kind/MODOP_EXPR whose comment says
that we expect to see MODOP_EXPRs only during template processing.
In this test we get there with processing_template_decl==0. The
MODOP_EXPR is created in:
/* Parse the requirement body. */
++processing_template_decl;
reqs = cp_parser_requirement_body (parser);
--processing_template_decl;
but we're not in a template when calling maybe_convert_cond which
calls verify_sequence_points which ends up calling lvalue_p on
the MODOP_EXPR. verify_sequence_points is a c-family/ function
so we couldn't make it stop recursing on REQUIRES_EXPR, so I suppose
we can do the following.
PR c++/126066
gcc/cp/ChangeLog:
* tree.cc (lvalue_kind) <case MODOP_EXPR>: If
!processing_template_decl, assert that the expression isn't
type-dependent.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-pr126066.C: New test.
---
gcc/cp/tree.cc | 8 ++++++--
gcc/testsuite/g++.dg/cpp2a/concepts-pr126066.C | 15 +++++++++++++++
2 files changed, 21 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr126066.C
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index e543cf14519..9094449ae24 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -281,8 +281,12 @@ lvalue_kind (const_tree ref)
case MODOP_EXPR:
/* We expect to see unlowered MODOP_EXPRs only during
- template processing. */
- gcc_assert (processing_template_decl);
+ template processing, but we can get here e.g. from the body of
+ a compound-requirement as well in which case make sure we
+ aren't operating on a type-dependent expr. */
+ gcc_assert (processing_template_decl
+ || !type_dependent_expression_p_push
+ (const_cast<tree> (ref)));
if (CLASS_TYPE_P (TREE_TYPE (TREE_OPERAND (ref, 0))))
goto default_;
else
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr126066.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-pr126066.C
new file mode 100644
index 00000000000..ff8a3a49261
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr126066.C
@@ -0,0 +1,15 @@
+// PR c++/126066
+// { dg-do compile { target c++20 } }
+// { dg-options "-Wall" }
+
+struct S { S& operator=(int); };
+
+void
+fn ()
+{
+ if constexpr (requires(int &a) { a = 0; }) { }
+ if constexpr (requires(S &s) { s = 0; }) { }
+}
+
+constexpr bool b = requires(int &a) { a = 0; };
+static_assert(requires(int &a) { a = 0; });
base-commit: d15703b27aa4924ca3438066ae0759e7379b3e0b
--
2.55.0
