[C++ PATCH] Fix ICE in cxx_eval_vec_init_1 (PR c++/51619)

[Jakub Jelinek]

Hi!

cxx_eval_vec_init_1 starts with:
  if (TREE_CODE (elttype) == ARRAY_TYPE)
    /* We only do this at the lowest level.  */;
  else if (value_init)
    {
      init = something;
    }
  else if (!init)
    {
      init = something_else;
    }

For the ARRAY_TYPE elttype (i.e. multidimensional array) we are
recursing.  If value_init is true, we ignore init, but
if init is originally NULL, we ICE trying to cp_build_array_ref
of NULL.  IMHO in that case we want to also ignore init and the
above code will fill init in the lowest cxx_eval_vec_init_1 recursion
when elttype is no longer ARRAY_TYPE.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2011-12-19  Jakub Jelinek  <ja...@redhat.com>

        PR c++/51619
        * semantics.c (cxx_eval_vec_init_1): If init is NULL for
        multidimensional array, just set eltinit to NULL_TREE.

        * g++.dg/cpp0x/pr51619.C: New test.

--- gcc/cp/semantics.c.jj       2011-12-19 09:21:01.000000000 +0100
+++ gcc/cp/semantics.c  2011-12-19 10:45:44.498472626 +0100
@@ -7065,7 +7065,7 @@ cxx_eval_vec_init_1 (const constexpr_cal
       if (TREE_CODE (elttype) == ARRAY_TYPE)
        {
          /* A multidimensional array; recurse.  */
-         if (value_init)
+         if (value_init || init == NULL_TREE)
            eltinit = NULL_TREE;
          else
            eltinit = cp_build_array_ref (input_location, init, idx,
--- gcc/testsuite/g++.dg/cpp0x/pr51619.C.jj     2011-12-19 10:49:45.128086227 
+0100
+++ gcc/testsuite/g++.dg/cpp0x/pr51619.C        2011-12-19 10:49:09.000000000 
+0100
@@ -0,0 +1,7 @@
+// PR c++/51619
+// { dg-do compile }
+// { dg-options "-std=c++0x" }
+
+struct A { virtual ~A(); };
+struct B { A a[1][1]; } b;
+struct C { A a[3][3]; } c;

        Jakub