[PATCH] Fix dwarf2out ICE on zero sized array initializer (PR debug/85252)

[Jakub Jelinek]

Hi!

As mentioned in the PR, we ICE on the following zero sized array
initializers, while domain is non-NULL and TYPE_MIN_VALUE is size_int (0),
TYPE_MAX_VALUE is NULL and not INTEGER_CST compare_tree_int assumes it is.

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

2018-04-06  Jakub Jelinek  <ja...@redhat.com>

        PR debug/85252
        * dwarf2out.c (rtl_for_decl_init): For STRING_CST initializer only
        build CONST_STRING if TYPE_MAX_VALUE is non-NULL and is INTEGER_CST.

        * gcc.dg/debug/pr85252.c: New test.

--- gcc/dwarf2out.c.jj  2018-04-04 16:13:43.141551164 +0200
+++ gcc/dwarf2out.c     2018-04-06 14:05:42.278496761 +0200
@@ -19596,6 +19596,8 @@ rtl_for_decl_init (tree init, tree type)
       if (is_int_mode (TYPE_MODE (enttype), &mode)
          && GET_MODE_SIZE (mode) == 1
          && domain
+         && TYPE_MAX_VALUE (domain)
+         && TREE_CODE (TYPE_MAX_VALUE (domain)) == INTEGER_CST
          && integer_zerop (TYPE_MIN_VALUE (domain))
          && compare_tree_int (TYPE_MAX_VALUE (domain),
                               TREE_STRING_LENGTH (init) - 1) == 0
--- gcc/testsuite/gcc.dg/debug/pr85252.c.jj     2018-04-06 14:08:02.507520855 
+0200
+++ gcc/testsuite/gcc.dg/debug/pr85252.c        2018-04-06 14:07:29.200514380 
+0200
@@ -0,0 +1,11 @@
+/* PR debug/85252 */
+/* { dg-do compile } */
+
+void
+foo (void)
+{
+  static char a[0] = "";
+  static char b[0] = "b";      /* { dg-warning "initializer-string for array 
of chars is too long" } */
+  static char c[1] = "c";
+  static char d[1] = "de";     /* { dg-warning "initializer-string for array 
of chars is too long" } */
+}

        Jakub