C++ PATCH for c++/89119 - ICE with value-initialization in template

[Marek Polacek]

While looking at the other PR I came across this ICE.  We're substituting

  {.a={[0 ... 3]=0}}

which contains a RANGE_EXPR that build_value_init_noctor created, but none
of the tsubst_* functions handle it.  As discussed in the PR, a RANGE_EXPR
will always be created with constant operands, so there's no need to recurse
further.

Bootstrapped/regtest running on x86_64-linux, ok for trunk and 8/7?

2019-01-30  Marek Polacek  <pola...@redhat.com>

        PR c++/89119 - ICE with value-initialization in template.
        * pt.c (tsubst_copy_and_build): Handle RANGE_EXPR.

        * g++.dg/cpp0x/initlist-value3.C: New test.

diff --git gcc/cp/pt.c gcc/cp/pt.c
index cb06a570d48..f92fa1a1813 100644
--- gcc/cp/pt.c
+++ gcc/cp/pt.c
@@ -19412,6 +19412,11 @@ tsubst_copy_and_build (tree t,
     case REQUIRES_EXPR:
       RETURN (tsubst_requires_expr (t, args, complain, in_decl));
 
+    case RANGE_EXPR:
+      /* No need to substitute further, a RANGE_EXPR will always be built
+        with constant operands.  */
+      RETURN (t);
+
     case NON_LVALUE_EXPR:
     case VIEW_CONVERT_EXPR:
       if (location_wrapper_p (t))
diff --git gcc/testsuite/g++.dg/cpp0x/initlist-value3.C 
gcc/testsuite/g++.dg/cpp0x/initlist-value3.C
new file mode 100644
index 00000000000..03db25d1652
--- /dev/null
+++ gcc/testsuite/g++.dg/cpp0x/initlist-value3.C
@@ -0,0 +1,23 @@
+// PR c++/89119
+// { dg-do compile { target c++11 } }
+
+struct S { int a[4]; };
+
+template<int N>
+struct R { int a[N]; };
+
+template <typename T>
+void
+fn ()
+{
+  constexpr auto s = S();
+  constexpr auto s2 = S{};
+  constexpr auto r = R<4>();
+  constexpr auto r2 = R<4>{};
+}
+
+void
+foo ()
+{
+  fn<int>();
+}