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

[Jakub Jelinek via Gcc-patches]

Hi!

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.

Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk.

2021-07-21  Jakub Jelinek  <ja...@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.

--- gcc/cp/semantics.c.jj       2021-07-15 10:16:12.972581906 +0200
+++ gcc/cp/semantics.c  2021-07-20 13:31:04.972039268 +0200
@@ -6070,7 +6070,8 @@ finish_omp_reduction_clause (tree c, boo
       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));
--- gcc/testsuite/g++.dg/gomp/pr101516.C.jj     2021-07-20 13:51:41.690789542 
+0200
+++ gcc/testsuite/g++.dg/gomp/pr101516.C        2021-07-20 13:51:16.463141545 
+0200
@@ -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" }
+  ;
+}

        Jakub