re PR debug/45882 (No debug info for vars depending on unused parameter)

	PR debug/45882
	* rtl.def (ENTRY_VALUE): Change format from "e" to "0".
	* rtl.h (ENTRY_VALUE_EXP): Define.
	* rtl.c (rtx_equal_p_cb, rtx_equal_p): Handle ENTRY_VALUE.
	* cselib.c (rtx_equal_for_cselib_p, cselib_hash_rtx): Likewise.
	* print-rtl.c (print_rtx): Likewise.
	* gengtype.c (adjust_field_rtx_def): Likewise.
	* var-tracking.c (vt_add_function_parameter): Adjust
	gen_rtx_ENTRY_VALUE uses, use ENTRY_VALUE_EXP macro.
	* dwarf2out.c (mem_loc_descriptor): Use ENTRY_VALUE_EXP macro.
	* cfgexpand.c (expand_debug_expr): If a SSA_NAME without
	partition is a default definition of a PARM_DECL, use ENTRY_VALUE
	of its DECL_INCOMING_RTL if possible, or its DECL_RTL if set.

	* gcc.dg/guality/pr45882.c: New test.

From-SVN: r171035

gcc/ChangeLog

 2011-03-16  Jakub Jelinek  <jakub@redhat.com>
 
+	PR debug/45882
+	* rtl.def (ENTRY_VALUE): Change format from "e" to "0".
+	* rtl.h (ENTRY_VALUE_EXP): Define.
+	* rtl.c (rtx_equal_p_cb, rtx_equal_p): Handle ENTRY_VALUE.
+	* cselib.c (rtx_equal_for_cselib_p, cselib_hash_rtx): Likewise.
+	* print-rtl.c (print_rtx): Likewise.
+	* gengtype.c (adjust_field_rtx_def): Likewise.
+	* var-tracking.c (vt_add_function_parameter): Adjust
+	gen_rtx_ENTRY_VALUE uses, use ENTRY_VALUE_EXP macro.
+	* dwarf2out.c (mem_loc_descriptor): Use ENTRY_VALUE_EXP macro.
+	* cfgexpand.c (expand_debug_expr): If a SSA_NAME without
+	partition is a default definition of a PARM_DECL, use ENTRY_VALUE
+	of its DECL_INCOMING_RTL if possible, or its DECL_RTL if set.
+
 	* final.c (final_scan_insn): Handle NOTE_INSN_CALL_ARG_LOCATION.
 	Call var_location debug hook even on CALL_INSNs.
 	(rest_of_clean_state): Don't print NOTE_INSN_CALL_ARG_LOCATION.

gcc/cfgexpand.c

@@ -3171,7 +3171,31 @@ expand_debug_expr (tree exp)
 	    int part = var_to_partition (SA.map, exp);
 
 	    if (part == NO_PARTITION)
-	      return NULL;
+	      {
+		/* If this is a reference to an incoming value of parameter
+		   that is never used in the code or where the incoming
+		   value is never used in the code, use PARM_DECL's
+		   DECL_RTL if set.  */
+		if (SSA_NAME_IS_DEFAULT_DEF (exp)
+		    && TREE_CODE (SSA_NAME_VAR (exp)) == PARM_DECL)
+		  {
+		    rtx incoming = DECL_INCOMING_RTL (SSA_NAME_VAR (exp));
+		    if (incoming
+			&& GET_MODE (incoming) != BLKmode
+			&& (REG_P (incoming)
+			    || (MEM_P (incoming) && REG_P (XEXP (incoming, 0)))))
+		      {
+			op0 = gen_rtx_ENTRY_VALUE (GET_MODE (incoming));
+			ENTRY_VALUE_EXP (op0) = incoming;
+			goto adjust_mode;
+		      }
+		    op0 = expand_debug_expr (SSA_NAME_VAR (exp));
+		    if (!op0)
+		      return NULL;
+		    goto adjust_mode;
+		  }
+		return NULL;
+	      }
 
 	    gcc_assert (part >= 0 && (unsigned)part < SA.map->num_partitions);
 

gcc/cselib.c

@@ -803,6 +803,10 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, enum machine_mode memmode)
       return DEBUG_IMPLICIT_PTR_DECL (x)
 	     == DEBUG_IMPLICIT_PTR_DECL (y);
 
+    case ENTRY_VALUE:
+      return rtx_equal_for_cselib_1 (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y),
+				     memmode);
+
     case LABEL_REF:
       return XEXP (x, 0) == XEXP (y, 0);
 
@@ -949,6 +953,10 @@ cselib_hash_rtx (rtx x, int create, enum machine_mode memmode)
 	      + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x));
       return hash ? hash : (unsigned int) DEBUG_IMPLICIT_PTR;
 
+    case ENTRY_VALUE:
+      hash += cselib_hash_rtx (ENTRY_VALUE_EXP (x), create, memmode);
+      return hash ? hash : (unsigned int) ENTRY_VALUE;
+
     case CONST_INT:
       hash += ((unsigned) CONST_INT << 7) + INTVAL (x);
       return hash ? hash : (unsigned int) CONST_INT;

gcc/dwarf2out.c

@@ -14028,14 +14028,14 @@ mem_loc_descriptor (rtx rtl, enum machine_mode mode,
     case ENTRY_VALUE:
       mem_loc_result = new_loc_descr (DW_OP_GNU_entry_value, 0, 0);
       mem_loc_result->dw_loc_oprnd1.val_class = dw_val_class_loc;
-      if (REG_P (XEXP (rtl, 0)))
+      if (REG_P (ENTRY_VALUE_EXP (rtl)))
 	mem_loc_result->dw_loc_oprnd1.v.val_loc
-	  = one_reg_loc_descriptor (dbx_reg_number (XEXP (rtl, 0)),
+	  = one_reg_loc_descriptor (dbx_reg_number (ENTRY_VALUE_EXP (rtl)),
 				    VAR_INIT_STATUS_INITIALIZED);
-      else if (MEM_P (XEXP (rtl, 0)) && REG_P (XEXP (XEXP (rtl, 0), 0)))
+      else if (MEM_P (ENTRY_VALUE_EXP (rtl)) && REG_P (XEXP (ENTRY_VALUE_EXP (rtl), 0)))
 	{
 	  dw_loc_descr_ref ref
-	    = mem_loc_descriptor (XEXP (rtl, 0), GET_MODE (rtl),
+	    = mem_loc_descriptor (ENTRY_VALUE_EXP (rtl), GET_MODE (rtl),
 				  VAR_INIT_STATUS_INITIALIZED);
 	  if (ref == NULL)
 	    return NULL;

gcc/gengtype.c

@@ -1101,6 +1101,8 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
 		t = symbol_union_tp, subname = "";
 	      else if (i == BARRIER && aindex >= 3)
 		t = scalar_tp, subname = "rt_int";
+	      else if (i == ENTRY_VALUE && aindex == 0)
+		t = rtx_tp, subname = "rt_rtx";
 	      else
 		{
 		  error_at_line 

gcc/print-rtl.c

@@ -334,6 +334,14 @@ print_rtx (const_rtx in_rtx)
 		     DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (in_rtx)));
 #endif
 	  }
+	else if (i == 0 && GET_CODE (in_rtx) == ENTRY_VALUE)
+	  {
+	    indent += 2;
+	    if (!sawclose)
+	      fprintf (outfile, " ");
+	    print_rtx (ENTRY_VALUE_EXP (in_rtx));
+	    indent -= 2;
+	  }
 	break;
 
       case 'e':

gcc/rtl.c

 /* RTL utility routines.
    Copyright (C) 1987, 1988, 1991, 1994, 1997, 1998, 1999, 2000, 2001, 2002,
-   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -412,6 +412,9 @@ rtx_equal_p_cb (const_rtx x, const_rtx y, rtx_equal_p_callback_function cb)
       return DEBUG_IMPLICIT_PTR_DECL (x)
 	     == DEBUG_IMPLICIT_PTR_DECL (y);
 
+    case ENTRY_VALUE:
+      return rtx_equal_p_cb (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y), cb);
+
     default:
       break;
     }
@@ -544,6 +547,9 @@ rtx_equal_p (const_rtx x, const_rtx y)
       return DEBUG_IMPLICIT_PTR_DECL (x)
 	     == DEBUG_IMPLICIT_PTR_DECL (y);
 
+    case ENTRY_VALUE:
+      return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y));
+
     default:
       break;
     }

gcc/rtl.def

@@ -718,9 +718,10 @@ DEF_RTL_EXPR(VAR_LOCATION, "var_location", "tei", RTX_EXTRA)
    addressable.  */
 DEF_RTL_EXPR(DEBUG_IMPLICIT_PTR, "debug_implicit_ptr", "t", RTX_OBJ)
 
-/* Represents value that argument had on function entry.  Should
-   be only used in VAR_LOCATION location expression.  */
-DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "e", RTX_OBJ)
+/* Represents value that argument had on function entry.  The
+   single argument is the DECL_INCOMING_RTL of the corresponding
+   parameter.  */
+DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "0", RTX_OBJ)
 
 /* All expressions from this point forward appear only in machine
    descriptions.  */

gcc/rtl.h

@@ -833,6 +833,10 @@ extern void rtl_check_failed_flag (const char *, const_rtx, const char *,
    but a value from enum reg_note.  */
 #define REG_NOTES(INSN)	XEXP(INSN, 7)
 
+/* In an ENTRY_VALUE this is the DECL_INCOMING_RTL of the argument in
+   question.  */
+#define ENTRY_VALUE_EXP(RTX) (RTL_CHECKC1 (RTX, 0, ENTRY_VALUE).rt_rtx)
+
 enum reg_note
 {
 #define DEF_REG_NOTE(NAME) NAME,

gcc/testsuite/ChangeLog

+2011-03-16  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/45882
+	* gcc.dg/guality/pr45882.c: New test.
+
 2011-03-15  Jason Merrill  <jason@redhat.com>
 
 	* g++.dg/cpp0x/constexpr-recursion.C: New.

gcc/testsuite/gcc.dg/guality/pr45882.c

+/* PR debug/45882 */
+/* { dg-do run } */
+/* { dg-options "-g" } */
+
+extern void abort (void);
+int a[1024];
+volatile short int v;
+
+__attribute__((noinline)) int
+foo (int i, int j)
+{
+  int b = i;		/* { dg-final { gdb-test 16 "b" "7" } } */
+  int c = i + 4;	/* { dg-final { gdb-test 16 "c" "11" } } */
+  int d = a[i];		/* { dg-final { gdb-test 16 "d" "112" } } */
+  int e = a[i + 6];	/* { dg-final { gdb-test 16 "e" "142" } } */
+  ++v;
+  return ++j;
+}
+
+int
+main (void)
+{
+  int l;
+  asm ("" : "=r" (l) : "0" (7));
+  a[7] = 112;
+  a[7 + 6] = 142;
+  if (foo (l, 7) != 8)
+    abort ();
+  return l - 7;
+}

gcc/var-tracking.c

@@ -8377,7 +8377,8 @@ vt_add_function_parameter (tree parm)
 	  el = (struct elt_loc_list *)
 	    ggc_alloc_cleared_atomic (sizeof (*el));
 	  el->next = val->locs;
-	  el->loc = gen_rtx_ENTRY_VALUE (GET_MODE (incoming), incoming);
+	  el->loc = gen_rtx_ENTRY_VALUE (GET_MODE (incoming));
+	  ENTRY_VALUE_EXP (el->loc) = incoming;
 	  el->setting_insn = get_insns ();
 	  val->locs = el;
 	  if (TREE_CODE (TREE_TYPE (parm)) == REFERENCE_TYPE
@@ -8394,7 +8395,8 @@ vt_add_function_parameter (tree parm)
 		  el = (struct elt_loc_list *)
 		    ggc_alloc_cleared_atomic (sizeof (*el));
 		  el->next = val->locs;
-		  el->loc = gen_rtx_ENTRY_VALUE (indmode, mem);
+		  el->loc = gen_rtx_ENTRY_VALUE (indmode);
+		  ENTRY_VALUE_EXP (el->loc) = mem;
 		  el->setting_insn = get_insns ();
 		  val->locs = el;
 		}