This patch is for the google/gcc-4_7 branch.
Backport pending upstream patch to output DW_AT_high_pc as a constant
instead of a relocated address. This significantly reduces the number
of entries used in the .debug_addr table with -gfission.
Tested: Ran regression tests and validate-failures.py.
2012-04-27 Mark Wielaard <m...@redhat.com>
* dwarf2out.h (enum dw_val_class): Add dw_val_class_high_pc.
* dwarf2out.c (dw_val_equal_p): Handle dw_val_class_high_pc.
(add_AT_low_high_pc): New function.
(AT_lbl): Handle dw_val_class_high_pc.
(print_die): Likewise.
(attr_checksum): Likewise.
(attr_checksum_ordered): Likewise.
(same_dw_val_p): Likewise.
(size_of_die): Likewise.
(value_format): Likewise.
(output_die): Likewise.
(gen_subprogram_die): Use add_AT_low_high_pc.
(add_high_low_attributes): Likewise.
(dwarf2out_finish): Likewise.
Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c (revision 189857)
+++ gcc/dwarf2out.c (working copy)
@@ -1666,6 +1666,7 @@ dw_val_equal_p (dw_val_node *a, dw_val_n
case dw_val_class_fde_ref:
return a->v.val_fde_index == b->v.val_fde_index;
case dw_val_class_lbl_id:
+ case dw_val_class_high_pc:
return strcmp (a->v.val_lbl_id, b->v.val_lbl_id) == 0;
case dw_val_class_str:
return a->v.val_str == b->v.val_str;
@@ -4549,6 +4550,35 @@ add_AT_data8 (dw_die_ref die, enum dwarf
add_dwarf_attr (die, &attr);
}
+/* Add DW_AT_low_pc and DW_AT_high_pc to a DIE. */
+static inline void
+add_AT_low_high_pc (dw_die_ref die, const char *lbl_low, const char *lbl_high,
+ bool force_direct)
+{
+ dw_attr_node attr;
+
+ attr.dw_attr = DW_AT_low_pc;
+ attr.dw_attr_val.val_class = dw_val_class_lbl_id;
+ attr.dw_attr_val.val_index = -1U;
+ attr.dw_attr_val.v.val_lbl_id = xstrdup (lbl_low);
+ add_dwarf_attr (die, &attr);
+ if (dwarf_split_debug_info && !force_direct)
+ set_AT_index (get_AT (die, DW_AT_low_pc), add_addr_table_entry (&attr));
+
+ attr.dw_attr = DW_AT_high_pc;
+ if (dwarf_version < 4)
+ attr.dw_attr_val.val_class = dw_val_class_lbl_id;
+ else
+ attr.dw_attr_val.val_class = dw_val_class_high_pc;
+ attr.dw_attr_val.val_index = -1U;
+ attr.dw_attr_val.v.val_lbl_id = xstrdup (lbl_high);
+ add_dwarf_attr (die, &attr);
+ if (attr.dw_attr_val.val_class == dw_val_class_lbl_id
+ && dwarf_split_debug_info && !force_direct)
+ set_AT_index (get_AT (die, DW_AT_high_pc), add_addr_table_entry (&attr));
+
+}
+
/* Hash and equality functions for debug_str_hash. */
static hashval_t
@@ -5005,7 +5035,8 @@ AT_lbl (dw_attr_ref a)
{
gcc_assert (a && (AT_class (a) == dw_val_class_lbl_id
|| AT_class (a) == dw_val_class_lineptr
- || AT_class (a) == dw_val_class_macptr));
+ || AT_class (a) == dw_val_class_macptr
+ || AT_class (a) == dw_val_class_high_pc));
return a->dw_attr_val.v.val_lbl_id;
}
@@ -5884,6 +5915,7 @@ print_die (dw_die_ref die, FILE *outfile
case dw_val_class_lbl_id:
case dw_val_class_lineptr:
case dw_val_class_macptr:
+ case dw_val_class_high_pc:
fprintf (outfile, "label: %s", AT_lbl (a));
break;
case dw_val_class_str:
@@ -6040,6 +6072,7 @@ attr_checksum (dw_attr_ref at, struct md
case dw_val_class_lbl_id:
case dw_val_class_lineptr:
case dw_val_class_macptr:
+ case dw_val_class_high_pc:
break;
case dw_val_class_file:
@@ -6312,6 +6345,7 @@ attr_checksum_ordered (enum dwarf_tag ta
case dw_val_class_lbl_id:
case dw_val_class_lineptr:
case dw_val_class_macptr:
+ case dw_val_class_high_pc:
break;
case dw_val_class_file:
@@ -6771,6 +6805,7 @@ same_dw_val_p (const dw_val_node *v1, co
case dw_val_class_lbl_id:
case dw_val_class_lineptr:
case dw_val_class_macptr:
+ case dw_val_class_high_pc:
return 1;
case dw_val_class_file:
@@ -8093,6 +8128,9 @@ size_of_die (dw_die_ref die)
case dw_val_class_vms_delta:
size += DWARF_OFFSET_SIZE;
break;
+ case dw_val_class_high_pc:
+ size += DWARF2_ADDR_SIZE;
+ break;
default:
gcc_unreachable ();
}
@@ -8412,6 +8450,17 @@ value_format (dw_attr_ref a)
case dw_val_class_data8:
return DW_FORM_data8;
+ case dw_val_class_high_pc:
+ switch (DWARF2_ADDR_SIZE)
+ {
+ case 4:
+ return DW_FORM_data4;
+ case 8:
+ return DW_FORM_data8;
+ default:
+ gcc_unreachable ();
+ }
+
default:
gcc_unreachable ();
}
@@ -8918,6 +8967,11 @@ output_die (dw_die_ref die)
break;
}
+ case dw_val_class_high_pc:
+ dw2_asm_output_delta (DWARF2_ADDR_SIZE, AT_lbl (a),
+ get_AT_low_pc (die), "DW_AT_high_pc");
+ break;
+
default:
gcc_unreachable ();
}
@@ -17987,19 +18041,20 @@ gen_subprogram_die (tree decl, dw_die_re
if (fde->dw_fde_begin)
{
/* We have already generated the labels. */
- add_AT_lbl_id (subr_die, DW_AT_low_pc, fde->dw_fde_begin, false);
- add_AT_lbl_id (subr_die, DW_AT_high_pc, fde->dw_fde_end, false);
+ add_AT_low_high_pc (subr_die, fde->dw_fde_begin,
+ fde->dw_fde_end, false);
}
else
{
/* Create start/end labels and add the range. */
- char label_id[MAX_ARTIFICIAL_LABEL_BYTES];
- ASM_GENERATE_INTERNAL_LABEL (label_id, FUNC_BEGIN_LABEL,
- FUNC_LABEL_ID (cfun));
- add_AT_lbl_id (subr_die, DW_AT_low_pc, label_id, false);
- ASM_GENERATE_INTERNAL_LABEL (label_id, FUNC_END_LABEL,
- FUNC_LABEL_ID (cfun));
- add_AT_lbl_id (subr_die, DW_AT_high_pc, label_id, false);
+ char label_id_low[MAX_ARTIFICIAL_LABEL_BYTES];
+ char label_id_high[MAX_ARTIFICIAL_LABEL_BYTES];
+ ASM_GENERATE_INTERNAL_LABEL (label_id_low, FUNC_BEGIN_LABEL,
+ current_function_funcdef_no);
+ ASM_GENERATE_INTERNAL_LABEL (label_id_high, FUNC_END_LABEL,
+ current_function_funcdef_no);
+ add_AT_low_high_pc (subr_die, label_id_low, label_id_high,
+ false);
}
#if VMS_DEBUGGING_INFO
@@ -18064,10 +18119,8 @@ gen_subprogram_die (tree decl, dw_die_re
dw_die_ref seg_die;
/* Do the 'primary' section. */
- add_AT_lbl_id (subr_die, DW_AT_low_pc,
- fde->dw_fde_begin, false);
- add_AT_lbl_id (subr_die, DW_AT_high_pc,
- fde->dw_fde_end, false);
+ add_AT_low_high_pc (subr_die, fde->dw_fde_begin,
+ fde->dw_fde_end, false);
/* Build a minimal DIE for the secondary section. */
seg_die = new_die (DW_TAG_subprogram,
@@ -18091,20 +18144,16 @@ gen_subprogram_die (tree decl, dw_die_re
add_AT_flag (seg_die, DW_AT_artificial, 1);
name = concat ("__second_sect_of_", name, NULL);
- add_AT_lbl_id (seg_die, DW_AT_low_pc,
- fde->dw_fde_second_begin, false);
- add_AT_lbl_id (seg_die, DW_AT_high_pc,
- fde->dw_fde_second_end, false);
+ add_AT_low_high_pc (seg_die, fde->dw_fde_second_begin,
+ fde->dw_fde_second_end, false);
add_name_attribute (seg_die, name);
if (want_pubnames ())
add_pubname_string (name, seg_die);
}
}
else
- {
- add_AT_lbl_id (subr_die, DW_AT_low_pc, fde->dw_fde_begin, false);
- add_AT_lbl_id (subr_die, DW_AT_high_pc, fde->dw_fde_end, false);
- }
+ add_AT_low_high_pc (subr_die, fde->dw_fde_begin, fde->dw_fde_end,
+ false);
}
#ifdef MIPS_DEBUGGING_INFO
@@ -18794,12 +18843,12 @@ add_high_low_attributes (tree stmt, dw_d
}
else
{
+ char label_high[MAX_ARTIFICIAL_LABEL_BYTES];
ASM_GENERATE_INTERNAL_LABEL (label, BLOCK_BEGIN_LABEL,
BLOCK_NUMBER (stmt));
- add_AT_lbl_id (die, DW_AT_low_pc, label, false);
- ASM_GENERATE_INTERNAL_LABEL (label, BLOCK_END_LABEL,
+ ASM_GENERATE_INTERNAL_LABEL (label_high, BLOCK_END_LABEL,
BLOCK_NUMBER (stmt));
- add_AT_lbl_id (die, DW_AT_high_pc, label, false);
+ add_AT_low_high_pc (die, label, label_high, false);
}
}
@@ -23543,12 +23592,8 @@ dwarf2out_finish (const char *filename)
{
/* Don't add if the CU has no associated code. */
if (text_section_used)
- {
- add_AT_lbl_id (main_comp_unit_die, DW_AT_low_pc, text_section_label,
- true);
- add_AT_lbl_id (main_comp_unit_die, DW_AT_high_pc, text_end_label,
- true);
- }
+ add_AT_low_high_pc (main_comp_unit_die, text_section_label,
+ text_end_label, true);
}
else
{
Index: gcc/dwarf2out.h
===================================================================
--- gcc/dwarf2out.h (revision 189857)
+++ gcc/dwarf2out.h (working copy)
@@ -154,7 +154,8 @@ enum dw_val_class
dw_val_class_file,
dw_val_class_data8,
dw_val_class_decl_ref,
- dw_val_class_vms_delta
+ dw_val_class_vms_delta,
+ dw_val_class_high_pc
};
/* Describe a floating point constant value, or a vector constant value. */
--
This patch is available for review at http://codereview.appspot.com/6453046
