c++: Ensure OpenMP reduction with reference type references complete type [PR101516]

The following testcase ICEs because we haven't verified if reduction decl
has reference type that TREE_TYPE of the reference is a complete type,
require_complete_type on the decl doesn't ensure that.

2021-07-21  Jakub Jelinek  <jakub@redhat.com>

	PR c++/101516
	* semantics.c (finish_omp_reduction_clause): Also call
	complete_type_or_else and return true if it fails.

	* g++.dg/gomp/pr101516.C: New test.

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index b97dc1f..331daf8 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6070,7 +6070,8 @@ finish_omp_reduction_clause (tree c, bool *need_default_ctor, bool *need_dtor)
       if (!processing_template_decl)
        {
          t = require_complete_type (t);
-         if (t == error_mark_node)
+         if (t == error_mark_node
+             || !complete_type_or_else (oatype, NULL_TREE))
            return true;
          tree size = size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (oatype),
                                  TYPE_SIZE_UNIT (type));

diff --git a/gcc/testsuite/g++.dg/gomp/pr101516.C b/gcc/testsuite/g++.dg/gomp/pr101516.C
new file mode 100644 (file)
index 0000000..48f60de
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/pr101516.C
@@ -0,0 +1,8 @@
+// PR c++/101516
+
+void
+foo (int (&v) [])
+{
+  #pragma omp parallel reduction (+:v) // { dg-error "invalid use of array with unspecified bounds" }
+  ;
+}