[PATCH][4.3] Fix PR38752, ICE in set_uids_in_ptset

[Richard Guenther]

We may get garbage (invalid code) in, so asserting is not a good idea.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to the
branch.

Richard.

2009-01-07  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/38752
	* tree-ssa-structalias.c (set_uids_in_ptset): Do not assert we
	find a subvariable as we might have invalid accesses.

	* gcc.c-torture/compile/pr38752.c: New testcase.

Index: gcc/tree-ssa-structalias.c
===================================================================
*** gcc/tree-ssa-structalias.c	(revision 143150)
--- gcc/tree-ssa-structalias.c	(working copy)
*************** set_uids_in_ptset (tree ptr, bitmap into
*** 4813,4820 ****
  	      if (tsize
  		  && host_integerp (tsize, 1))
  		size = TREE_INT_CST_LOW (tsize);
! 	      sft = get_first_overlapping_subvar (sv, vi->offset, size, &j);
! 	      gcc_assert (sft);
  	      for (; VEC_iterate (tree, sv, j, sft); ++j)
  		{
  		  if (SFT_OFFSET (sft) > vi->offset
--- 4813,4819 ----
  	      if (tsize
  		  && host_integerp (tsize, 1))
  		size = TREE_INT_CST_LOW (tsize);
! 	      get_first_overlapping_subvar (sv, vi->offset, size, &j);
  	      for (; VEC_iterate (tree, sv, j, sft); ++j)
  		{
  		  if (SFT_OFFSET (sft) > vi->offset
Index: gcc/testsuite/gcc.c-torture/compile/pr38752.c
===================================================================
*** gcc/testsuite/gcc.c-torture/compile/pr38752.c	(revision 0)
--- gcc/testsuite/gcc.c-torture/compile/pr38752.c	(revision 0)
***************
*** 0 ****
--- 1,25 ----
+ typedef struct
+ {
+   int             baddr;
+ } mstruct_t;
+ 
+ static struct
+ {
+   unsigned int    mapnum;
+   mstruct_t       unused;
+ } mtab;
+ 
+ static mstruct_t *mactab = &mtab.unused;
+ 
+ int
+ main(void)
+ {
+   int i;
+   int addr;
+ 
+   for (i=1; i <= mtab.mapnum; i++)
+     if (addr < mactab[i].baddr)
+       break;
+   return 0;
+ }
+