https://gcc.gnu.org/g:b9ac51a843f9dc807b00ab7f49f64968807a4ee8
commit r15-3938-gb9ac51a843f9dc807b00ab7f49f64968807a4ee8
Author: Nathaniel Shead <nathanielosh...@gmail.com>
Date: Fri Sep 20 00:05:04 2024 +1000
c++: Don't strip USING_DECLs when updating local bindings [PR116748]
Currently update_binding strips USING_DECLs too eagerly, leading to ICEs
in pop_local_decl as it can't find the decl it's popping in the binding
list. Let's rather try to keep the original USING_DECL around.
This also means that using59.C can point to the location of the
using-decl rather than the underlying object directly; this is in the
direction required to fix PR c++/106851 (though more work is needed to
emit properly helpful diagnostics here).
PR c++/116748
gcc/cp/ChangeLog:
* name-lookup.cc (update_binding): Maintain USING_DECLs in the
binding slots.
gcc/testsuite/ChangeLog:
* g++.dg/lookup/using59.C: Update location.
* g++.dg/lookup/using69.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
Reviewed-by: Jason Merrill <ja...@redhat.com>
Diff:
---
gcc/cp/name-lookup.cc | 12 +++++++-----
gcc/testsuite/g++.dg/lookup/using59.C | 4 ++--
gcc/testsuite/g++.dg/lookup/using69.C | 10 ++++++++++
3 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index eb365b259d92..a2f94e0f363e 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -3005,6 +3005,8 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
if (old == error_mark_node)
old = NULL_TREE;
+
+ tree old_bval = old;
old = strip_using_decl (old);
if (DECL_IMPLICIT_TYPEDEF_P (decl))
@@ -3021,7 +3023,7 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
gcc_checking_assert (!to_type);
hide_type = hiding;
to_type = decl;
- to_val = old;
+ to_val = old_bval;
}
else
hide_value = hiding;
@@ -3034,7 +3036,7 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
/* OLD is an implicit typedef. Move it to to_type. */
gcc_checking_assert (!to_type);
- to_type = old;
+ to_type = old_bval;
hide_type = hide_value;
old = NULL_TREE;
hide_value = false;
@@ -3093,7 +3095,7 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
{
if (same_type_p (TREE_TYPE (old), TREE_TYPE (decl)))
/* Two type decls to the same type. Do nothing. */
- return old;
+ return old_bval;
else
goto conflict;
}
@@ -3106,7 +3108,7 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
/* The new one must be an alias at this point. */
gcc_assert (DECL_NAMESPACE_ALIAS (decl));
- return old;
+ return old_bval;
}
else if (TREE_CODE (old) == VAR_DECL)
{
@@ -3121,7 +3123,7 @@ update_binding (cp_binding_level *level, cxx_binding
*binding, tree *slot,
else
{
conflict:
- diagnose_name_conflict (decl, old);
+ diagnose_name_conflict (decl, old_bval);
to_val = NULL_TREE;
}
}
diff --git a/gcc/testsuite/g++.dg/lookup/using59.C
b/gcc/testsuite/g++.dg/lookup/using59.C
index 3c3a73c28d59..b7ec325d2348 100644
--- a/gcc/testsuite/g++.dg/lookup/using59.C
+++ b/gcc/testsuite/g++.dg/lookup/using59.C
@@ -1,10 +1,10 @@
namespace Y
{
- extern int I; // { dg-message "previous declaration" }
+ extern int I;
}
-using Y::I;
+using Y::I; // { dg-message "previous declaration" }
extern int I; // { dg-error "conflicts with a previous" }
extern int J;
diff --git a/gcc/testsuite/g++.dg/lookup/using69.C
b/gcc/testsuite/g++.dg/lookup/using69.C
new file mode 100644
index 000000000000..7d52b73b9ce0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/using69.C
@@ -0,0 +1,10 @@
+// PR c++/116748
+
+namespace ns {
+ struct empty;
+}
+
+void foo() {
+ using ns::empty;
+ int empty;
+}
