[PATCH] [PR c++/84968] reject stmt-exprs in noexcept constexprs

[Alexandre Oliva]

We reject extended statement-expressions in template parameters, so we
might as well reject them in constant expressions used in noexcept
specifications.

Regstrapped on i686- and x86_64-linux-gnu.  Ok to install?

for  gcc/cp/ChangeLog

        PR c++/84968
        * tree.c (strip_typedefs_expr): Reject STATEMENT_LISTs.

for  gcc/testsuite/ChangeLog

        PR c++/84968
        * g++.dg/eh/pr84968.C: New.
---
 gcc/cp/tree.c                     |    4 ++++
 gcc/testsuite/g++.dg/eh/pr84968.C |   15 +++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/eh/pr84968.C

diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index f1a90bdec0fc..070bd11a0591 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1785,6 +1785,10 @@ strip_typedefs_expr (tree t, bool *remove_attributes)
       error ("lambda-expression in a constant expression");
       return error_mark_node;
 
+    case STATEMENT_LIST:
+      error ("statement-expression in a constant expression");
+      return error_mark_node;
+
     default:
       break;
     }
diff --git a/gcc/testsuite/g++.dg/eh/pr84968.C 
b/gcc/testsuite/g++.dg/eh/pr84968.C
new file mode 100644
index 000000000000..23c49f477a88
--- /dev/null
+++ b/gcc/testsuite/g++.dg/eh/pr84968.C
@@ -0,0 +1,15 @@
+// { dg-do compile { target c++11 } }
+
+// { dg-options "" }
+
+union b;
+
+struct S {
+  template <typename>
+  void a()
+    try {
+    } catch (int ()
+            noexcept (({ union b a; true; }))) // { dg-error "constant" }
+  {
+  }
+};


-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer