Hi!
We ICE on the following testcase during error recovery, both new_parm
and old_parm are error_mark_node, the ICE is on
error ("redefinition of default argument for %q+#D", new_parm);
inform (DECL_SOURCE_LOCATION (old_parm),
"original definition appeared here");
where we don't print anything useful for new_parm and ICE trying to
access DECL_SOURCE_LOCATION of old_parm. I think we shouldn't diagnose
anything when either of the parms is erroneous, GCC 11 before
merge_default_template_args has been added was doing
if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
|| TREE_VEC_ELT (parms, i) == error_mark_node)
continue;
tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
if (error_operand_p (tmpl_parm))
return false;
in redeclare_class_template.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-01-04 Jakub Jelinek <ja...@redhat.com>
PR c++/108206
* decl.cc (merge_default_template_args): Return false if either
new_parm or old_parm are erroneous.
* g++.dg/template/pr108206.C: New test.
--- gcc/cp/decl.cc.jj 2022-12-22 11:09:52.026181629 +0100
+++ gcc/cp/decl.cc 2023-01-03 18:11:25.202223528 +0100
@@ -1556,6 +1556,8 @@ merge_default_template_args (tree new_pa
tree old_parm = TREE_VALUE (TREE_VEC_ELT (old_parms, i));
tree& new_default = TREE_PURPOSE (TREE_VEC_ELT (new_parms, i));
tree& old_default = TREE_PURPOSE (TREE_VEC_ELT (old_parms, i));
+ if (error_operand_p (new_parm) || error_operand_p (old_parm))
+ return false;
if (new_default != NULL_TREE && old_default != NULL_TREE)
{
auto_diagnostic_group d;
--- gcc/testsuite/g++.dg/template/pr108206.C.jj 2023-01-03 18:14:18.768730450
+0100
+++ gcc/testsuite/g++.dg/template/pr108206.C 2023-01-03 18:13:40.427281176
+0100
@@ -0,0 +1,5 @@
+// PR c++/108206
+// { dg-do compile { target c++11 } }
+
+template <X x, typename T1> void foo (T1); // { dg-error "'X' has not been
declared" }
+template <X x, typename T2> void foo (T2); // { dg-error "'X' has not been
declared" }
Jakub
