[patch] Fix ICEs when DEBUG_MANGLE is enabled

[Cary Coutant]

This patch fixes a few ICEs I encountered when enabling DEBUG_MANGLE.
I've also changed dump_substitution_candidates to output the substitution
index in base 36, to match the actual mangled name.

OK for trunk?

-cary


2013-11-13  Cary Coutant  <ccout...@google.com>

gcc/
        * cp/mangle.c (to_base36): New function.
        (dump_substitution_candidates): Add checks for NULL.
        Print substitution index in base 36.


commit 5ece725d55f104dd6499ac261380a9c9c4002613
Author: Cary Coutant <ccout...@google.com>
Date:   Wed Nov 13 09:28:58 2013 -0800

    Fix ICEs when DEBUG_MANGLE is enabled.

diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 202fafc..56c1844 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -301,6 +301,19 @@ decl_is_template_id (const tree decl, tree* const 
template_info)
   return 0;
 }
 
+/* Convert VAL to base 36.  */
+
+static const char *
+to_base36 (int val)
+{
+  static char buffer[sizeof (HOST_WIDE_INT) * 8 + 1];
+  unsigned count;
+
+  count = hwint_to_ascii (number, 36, buffer + sizeof (buffer) - 1, 1);
+  buffer[sizeof (buffer) - 1] = '\0';
+  return buffer + sizeof (buffer) - 1 - count;
+}
+
 /* Produce debugging output of current substitution candidates.  */
 
 static void
@@ -317,12 +330,27 @@ dump_substitution_candidates (void)
       if (i > 0)
        fprintf (stderr, "                    ");
       if (DECL_P (el))
-       name = IDENTIFIER_POINTER (DECL_NAME (el));
+        {
+          if (DECL_NAME (el))
+            name = IDENTIFIER_POINTER (DECL_NAME (el));
+        }
       else if (TREE_CODE (el) == TREE_LIST)
-       name = IDENTIFIER_POINTER (DECL_NAME (TREE_VALUE (el)));
+        {
+          tree val = TREE_VALUE (el);
+          if (TREE_CODE (val) == IDENTIFIER_NODE)
+            name = IDENTIFIER_POINTER (val);
+          else if (DECL_P (val))
+            name = IDENTIFIER_POINTER (DECL_NAME (val));
+        }
       else if (TYPE_NAME (el))
-       name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (el)));
-      fprintf (stderr, " S%d_ = ", i - 1);
+        {
+          if (DECL_NAME (TYPE_NAME (el)))
+            name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (el)));
+        }
+      if (i == 0)
+        fprintf (stderr, " S_ = ");
+      else
+        fprintf (stderr, " S%s_ = ", to_base36 (i - 1));
       if (TYPE_P (el) &&
          (CP_TYPE_RESTRICT_P (el)
           || CP_TYPE_VOLATILE_P (el)