re PR middle-end/49308 (segfault in rest_of_handle_ud_dce () at gcc/gcc/dce.c:518)

	PR middle-end/49308
	* dce.c (reset_unmarked_insns_debug_uses): Avoid shadowing insn
	variable.  After resetting and rescanning insn continue with previous
	statement.

	* gfortran.dg/pr49308.f90: New test.

From-SVN: r174839

gcc/ChangeLog

+2011-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/49308
+	* dce.c (reset_unmarked_insns_debug_uses): Avoid shadowing insn
+	variable.  After resetting and rescanning insn continue with previous
+	statement.
+
 2011-06-09  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* configure.ac (gcc_cv_as_hidden): Enable on *-*-darwin*.

gcc/dce.c

@@ -514,11 +514,11 @@ reset_unmarked_insns_debug_uses (void)
 	      struct df_link *defs;
 	      for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
 		{
-		  rtx insn;
+		  rtx ref_insn;
 		  if (DF_REF_IS_ARTIFICIAL (defs->ref))
 		    continue;
-		  insn = DF_REF_INSN (defs->ref);
-		  if (!marked_insn_p (insn))
+		  ref_insn = DF_REF_INSN (defs->ref);
+		  if (!marked_insn_p (ref_insn))
 		    break;
 		}
 	      if (!defs)
@@ -527,6 +527,7 @@ reset_unmarked_insns_debug_uses (void)
 		 each of the DEFs?  */
 	      INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
 	      df_insn_rescan_debug_internal (insn);
+	      break;
 	    }
 	}
 }

gcc/testsuite/ChangeLog

+2011-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/49308
+	* gfortran.dg/pr49308.f90: New test.
+
 2011-06-08  Jason Merrill  <jason@redhat.com>
 
 	* g++.dg/cpp0x/noexcept11.C: New.

gcc/testsuite/gfortran.dg/pr49308.f90

+! PR middle-end/49308
+! { dg-do compile }
+! { dg-options "-O2 -funroll-loops -g" }
+
+subroutine foo(n, b, d, e)
+  type t
+    integer :: f
+  end type t
+  type s
+    type(t), pointer :: g
+  end type s
+  type u
+    type(s), dimension(:), pointer :: h
+  end type
+  integer :: i, k, n
+  type(u), pointer :: a, e
+  character(len=250) :: b, c, d
+  logical :: l
+  do i = 1, n
+    j = i - 1
+    if (j/=0) c = trim(b) // adjustl(d(j))
+  end do
+  a => e
+  do k = 1, size(a%h)
+     l = (a%h(k)%g%f == a%h(1)%g%f)
+     if (.not.(l)) call bar()
+  enddo
+end subroutine foo