From fc349931adcf1024ee95e0a0cd98cf4a41996093 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Wed, 4 Jan 2023 18:42:31 +0100 Subject: [PATCH] c++: Error recovery in merge_default_template_args [PR108206] 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. 2023-01-04 Jakub Jelinek 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 | 2 ++ gcc/testsuite/g++.dg/template/pr108206.C | 5 +++++ 2 files changed, 7 insertions(+) create mode 100644 gcc/testsuite/g++.dg/template/pr108206.C diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 3c0355a1c39..66e7d9ff50e 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -1556,6 +1556,8 @@ merge_default_template_args (tree new_parms, tree old_parms, bool class_p) 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; diff --git a/gcc/testsuite/g++.dg/template/pr108206.C b/gcc/testsuite/g++.dg/template/pr108206.C new file mode 100644 index 00000000000..9362d261bea --- /dev/null +++ b/gcc/testsuite/g++.dg/template/pr108206.C @@ -0,0 +1,5 @@ +// PR c++/108206 +// { dg-do compile { target c++11 } } + +template void foo (T1); // { dg-error "'X' has not been declared" } +template void foo (T2); // { dg-error "'X' has not been declared" }