Patch for Warning About Unused Parameters

[Dave Brolley <brolley at cygnus dot com>]

Hi,

Attached is a patch which corrects a problem where warning are not
generated for some unused function parameters. Compiling the attached
test case with -W -Wall -O results in no warnings for arg3 and arg5.

Dave

13529.c

Index: function.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/function.c,v
retrieving revision 1.65
diff -c -p -c -p -r1.65 function.c
*** function.c	1999/01/19 10:31:52	1.65
--- function.c	1999/01/20 23:01:08
*************** assign_parms (fndecl, second_time)
*** 4378,4383 ****
--- 4378,4384 ----
  	  if (nominal_mode != passed_mode
  	      || promoted_nominal_mode != promoted_mode)
  	    {
+ 	      int save_tree_used;
  	      /* ENTRY_PARM has been converted to PROMOTED_MODE, its
  		 mode, by the caller.  We now have to convert it to 
  		 NOMINAL_MODE, if different.  However, PARMREG may be in
*************** assign_parms (fndecl, second_time)
*** 4404,4411 ****
--- 4405,4415 ----
  	      push_to_sequence (conversion_insns);
  	      tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
  
+ 	      /* TREE_USED gets set erroneously during expand_assignment.  */
+ 	      save_tree_used = TREE_USED (parm);
  	      expand_assignment (parm,
  				 make_tree (nominal_type, tempreg), 0, 0);
+ 	      TREE_USED (parm) = save_tree_used;
  	      conversion_insns = get_insns ();
  	      did_conversion = 1;
  	      end_sequence ();