Re: c/9516: [2003-02-01] Internal error when using a big array

["Christian Ehrhardt" <ehrhardt@mathematik.uni-ulm.de>]

The following reply was made to PR c/9516; it has been noted by GNATS.

From: "Christian Ehrhardt" <ehrhardt@mathematik.uni-ulm.de>
To: gcc-gnats@gcc.gnu.org, p.allix@ifrance.com, gcc-bugs@gcc.gnu.org,
  nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org
Cc:  
Subject: Re: c/9516: [2003-02-01] Internal error when using a big array
Date: Fri, 4 Apr 2003 19:48:41 +0200

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9516
 
 Hi,
 
 this PR is about a segfault when initializing an array like this:
 
 unsigned char tab[] = { 1,2,3,4,<several million initializer element> };
 
 The reason is a stack overflow because the initializer elements are
 in a TREE_LIST and this list is passed to expr.c:safe_from_p which
 does an infinite recursion in this piece of code:
 
     case 'x':
       if (TREE_CODE (exp) == TREE_LIST)
         return ((TREE_VALUE (exp) == 0
                  || safe_from_p (x, TREE_VALUE (exp), 0))
                 && (TREE_CHAIN (exp) == 0
                     || safe_from_p (x, TREE_CHAIN (exp), 0)));
 
 I guess that rewriting this as:
     case 'x':
       if (TREE_CODE (exp) == TREE_LIST)
 	{
 	  tree tmp;
 	  for (tmp = exp; tmp; tmp = TREE_CHAIN(tmp))
 	    {
 	      if (TREE_VALUE(exp) != 0 && !safe_from_p (x, TREE_VALUE (tmp), 0))
 		return 0;
 	    }
 	  return 1;
 	}
 
 should fix this PR. I'll bootstrap and regtest.
 
    regards  Christian
 
 -- 
 THAT'S ALL FOLKS!