[RFA] dwarf2read.c: Add complaint for out of bounds DW_AT_ranges attribute

[Kevin Buettner <kevinb@redhat.com>]

This one's almost obvious...

GDB for the FR-V target was segfaulting when issued the "maint
check-symtabs" command.  Clearly this is an indication that something
is wrong with the toolchain elsewhere, but GDB should not segfault
when it encounters bad debug info.

Okay?

	* dwarf2read.c (dwarf2_get_pc_bounds): Complain if offset
	associated with DW_AT_ranges attribute is out of bounds.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.101
diff -u -p -r1.101 dwarf2read.c
--- dwarf2read.c	9 Sep 2003 23:23:05 -0000	1.101
+++ dwarf2read.c	10 Sep 2003 21:11:27 -0000
@@ -2253,7 +2253,7 @@ dwarf2_get_pc_bounds (struct die_info *d
 	  unsigned int addr_size = cu_header->addr_size;
 	  CORE_ADDR mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
 	  /* Value of the DW_AT_ranges attribute is the offset in the
-	     .debug_renges section.  */
+	     .debug_ranges section.  */
 	  unsigned int offset = DW_UNSND (attr);
 	  /* Base address selection entry.  */
 	  CORE_ADDR base;
@@ -2266,6 +2266,14 @@ dwarf2_get_pc_bounds (struct die_info *d
  
 	  found_base = cu_header->base_known;
 	  base = cu_header->base_address;
+
+	  if (offset >= dwarf_ranges_size)
+	    {
+	      complaint (&symfile_complaints,
+	                 "Offset %d out of bounds for DW_AT_ranges attribute",
+			 offset);
+	      return 0;
+	    }
 	  buffer = dwarf_ranges_buffer + offset;
 
 	  /* Read in the largest possible address.  */