On 1/4/25 10:13 AM, Simon Martin wrote:
The invalid case in this PR trips on an assertion in
build_class_member_access_expr that build_base_path would never return
an error_mark_node, which is actually incorrect if the object involves a
tree with an error_mark_node DECL_INITIAL, like here.
This patch simply removes the assertion, even though it has been here
for 22+ years (r0-44513-g50ad96428042fa). An alternative would be to
assert that object != error_mark_node || seen_error (), but that'd be
virtually not asserting anything IMO.
That is an important difference: it asserts that if we run into trouble,
we've actually given an error message. Silently ignoring
error_mark_node frequently leads to wrong-code bugs.
OK with that change.
Successfully tested on x86_64-pc-linux-gnu.
PR c++/118225
gcc/cp/ChangeLog:
* typeck.cc (build_class_member_access_expr): Remove incorrect
gcc_assert.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-ice21.C: New test.
---
gcc/cp/typeck.cc | 3 ---
gcc/testsuite/g++.dg/cpp0x/constexpr-ice21.C | 17 +++++++++++++++++
2 files changed, 17 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-ice21.C
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 1f9a74166f4..14912254c9c 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -2978,9 +2978,6 @@ build_class_member_access_expr (cp_expr object, tree
member,
/* Convert to the base. */
object = build_base_path (PLUS_EXPR, object, binfo,
/*nonnull=*/1, complain);
- /* If we found the base successfully then we should be able
- to convert to it successfully. */
- gcc_assert (object != error_mark_node);
}
/* If MEMBER is from an anonymous aggregate, we have converted
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-ice21.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-ice21.C
new file mode 100644
index 00000000000..46273654f24
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-ice21.C
@@ -0,0 +1,17 @@
+// PR c++/118225
+// { dg-do "compile" { target c++11} }
+
+struct NoMut1 { int a, b; };
+struct NoMut3 : virtual NoMut1 {
+ constexpr NoMut3(int a, int b) // { dg-error "virtual base" "" { target
c++23 } }
+ : NoMut1{a, b}
+ {} // { dg-error "virtual base" }
+};
+void mutable_subobjects() {
+ constexpr NoMut3 nm3 = {1, 2}; // { dg-error "call to non" }
+ struct A {
+ void f() {
+ static_assert(nm3.a == 1, ""); // { dg-error "local variable" }
+ }
+ };
+}
