commit 49fced1206db40c71208c201165d65f92c69cebe
Author: Mark Wielaard <mark@klomp.org>
Date: Sun Mar 5 23:37:54 2017 +0100
gas: Emit name, comp_dir and producer strings in .debug_str.
Putting the name, comp_dir and producer strings in the .debug_str section
makes it possible to share them across CUs. This saves a small amount of
space (about ~20K on a glibc libc.so.6 build with debuginfo). And makes
it easier for tools like rpm debugedit to adjust the source paths when
generating separate debuginfo files.
gas/
* dwarf2dbg.c (out_debug_abbrev): Use DW_FORM_strp instead of
DW_FORM_string for DW_AT_name, DW_AT_comp_dir and DW_AT_producer.
(out_debug_info): Accept symbols to name, comp_dir and producer
in the .debug_str section and emit those offsets not full strings.
(out_debug_str): New function that outputs the strings for name,
comp_dir and producer in .debug_str and generates symbols to
those strings.
(out_debug_line): Create a .debug_str section if necessary and
call out_debug_str before calling out_debug_info.
* testsuite/gas/aarch64/dwarf.d: Add extra section symbol to
expected output.
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index 4bb658b..e02b6e8 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -1726,9 +1726,9 @@ out_debug_abbrev (segT abbrev_seg,
else
out_abbrev (DW_AT_ranges, DW_FORM_data8);
}
- out_abbrev (DW_AT_name, DW_FORM_string);
- out_abbrev (DW_AT_comp_dir, DW_FORM_string);
- out_abbrev (DW_AT_producer, DW_FORM_string);
+ out_abbrev (DW_AT_name, DW_FORM_strp);
+ out_abbrev (DW_AT_comp_dir, DW_FORM_strp);
+ out_abbrev (DW_AT_producer, DW_FORM_strp);
out_abbrev (DW_AT_language, DW_FORM_data2);
out_abbrev (0, 0);
@@ -1739,15 +1739,11 @@ out_debug_abbrev (segT abbrev_seg,
/* Emit a description of this compilation unit for .debug_info. */
static void
-out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg)
+out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg,
+ symbolS *name_sym, symbolS *comp_dir_sym, symbolS *producer_sym)
{
- char producer[128];
- const char *comp_dir;
- const char *dirname;
expressionS exp;
symbolS *info_end;
- char *p;
- int len;
int sizeof_offset;
sizeof_offset = out_header (info_seg, &exp);
@@ -1798,10 +1794,38 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg)
TC_DWARF2_EMIT_OFFSET (section_symbol (ranges_seg), sizeof_offset);
}
+ /* DW_AT_name, DW_AT_comp_dir and DW_AT_producer. Symbols in .debug_str
+ setup in out_debug_str below. */
+ TC_DWARF2_EMIT_OFFSET (name_sym, sizeof_offset);
+ TC_DWARF2_EMIT_OFFSET (comp_dir_sym, sizeof_offset);
+ TC_DWARF2_EMIT_OFFSET (producer_sym, sizeof_offset);
+
+ /* DW_AT_language. Yes, this is probably not really MIPS, but the
+ dwarf2 draft has no standard code for assembler. */
+ out_two (DW_LANG_Mips_Assembler);
+
+ symbol_set_value_now (info_end);
+}
+
+/* Emit the three debug strings needed in .debug_str and setup symbols
+ to them for use in out_debug_info. */
+static void
+out_debug_str (segT str_seg, symbolS **name_sym, symbolS **comp_dir_sym,
+ symbolS **producer_sym)
+{
+ char producer[128];
+ const char *comp_dir;
+ const char *dirname;
+ char *p;
+ int len;
+
+ subseg_set (str_seg, 0);
+
/* DW_AT_name. We don't have the actual file name that was present
on the command line, so assume files[1] is the main input file.
We're not supposed to get called unless at least one line number
entry was emitted, so this should always be defined. */
+ *name_sym = symbol_temp_new_now ();
if (files_in_use == 0)
abort ();
if (files[1].dir)
@@ -1823,22 +1847,18 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg)
memcpy (p, files[1].filename, len);
/* DW_AT_comp_dir */
+ *comp_dir_sym = symbol_temp_new_now ();
comp_dir = remap_debug_filename (getpwd ());
len = strlen (comp_dir) + 1;
p = frag_more (len);
memcpy (p, comp_dir, len);
/* DW_AT_producer */
+ *producer_sym = symbol_temp_new_now ();
sprintf (producer, "GNU AS %s", VERSION);
len = strlen (producer) + 1;
p = frag_more (len);
memcpy (p, producer, len);
-
- /* DW_AT_language. Yes, this is probably not really MIPS, but the
- dwarf2 draft has no standard code for assembler. */
- out_two (DW_LANG_Mips_Assembler);
-
- symbol_set_value_now (info_end);
}
void
@@ -1907,19 +1927,22 @@ dwarf2_finish (void)
out_debug_line (line_seg);
/* If this is assembler generated line info, and there is no
- debug_info already, we need .debug_info and .debug_abbrev
- sections as well. */
+ debug_info already, we need .debug_info, .debug_abbrev and
+ .debug_str sections as well. */
if (emit_other_sections)
{
segT abbrev_seg;
segT aranges_seg;
segT ranges_seg;
+ segT str_seg;
+ symbolS *name_sym, *comp_dir_sym, *producer_sym;
gas_assert (all_segs);
info_seg = subseg_new (".debug_info", 0);
abbrev_seg = subseg_new (".debug_abbrev", 0);
aranges_seg = subseg_new (".debug_aranges", 0);
+ str_seg = subseg_new (".debug_str", 0);
bfd_set_section_flags (stdoutput, info_seg,
SEC_READONLY | SEC_DEBUGGING);
@@ -1927,6 +1950,10 @@ dwarf2_finish (void)
SEC_READONLY | SEC_DEBUGGING);
bfd_set_section_flags (stdoutput, aranges_seg,
SEC_READONLY | SEC_DEBUGGING);
+ bfd_set_section_flags (stdoutput, str_seg,
+ (SEC_READONLY | SEC_DEBUGGING
+ | SEC_MERGE | SEC_STRINGS));
+ str_seg->entsize = 1;
record_alignment (aranges_seg, ffs (2 * sizeof_address) - 1);
@@ -1943,6 +1970,8 @@ dwarf2_finish (void)
out_debug_aranges (aranges_seg, info_seg);
out_debug_abbrev (abbrev_seg, info_seg, line_seg);
- out_debug_info (info_seg, abbrev_seg, line_seg, ranges_seg);
+ out_debug_str (str_seg, &name_sym, &comp_dir_sym, &producer_sym);
+ out_debug_info (info_seg, abbrev_seg, line_seg, ranges_seg,
+ name_sym, comp_dir_sym, producer_sym);
}
}
--- binutils.orig/gas/testsuite/gas/aarch64/dwarf.d 2017-03-06 11:52:17.411654603 +0000
+++ binutils-2.27/gas/testsuite/gas/aarch64/dwarf.d 2017-03-06 11:57:13.672958520 +0000
@@ -1,7 +1,7 @@
#readelf: -s --debug-dump=aranges
#as: -g
-Symbol table '.symtab' contains 10 entries:
+Symbol table '.symtab' contains 11 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000000000000 0 SECTION LOCAL DEFAULT 1
@@ -11,8 +11,9 @@ Symbol table '.symtab' contains 10 entri
5: 0000000000000000 0 SECTION LOCAL DEFAULT 6
6: 0000000000000000 0 SECTION LOCAL DEFAULT 8
7: 0000000000000000 0 SECTION LOCAL DEFAULT 4
- 8: 0000000000000000 0 SECTION LOCAL DEFAULT 9
- 9: 0000000000000000 8 FUNC GLOBAL DEFAULT 1 testfunc
+ 8: 0+ 0 SECTION LOCAL DEFAULT 11[ ]+
+ 9: 0+ 0 SECTION LOCAL DEFAULT 9[ ]+
+ 10: 0+ 8 FUNC GLOBAL DEFAULT 1 testfunc
Contents of the .debug_aranges section:
Length: 44
--- binutils.orig/gas/config/tc-s390.c 2017-07-19 15:48:00.309643692 +0100
+++ binutils-2.27/gas/config/tc-s390.c 2017-07-19 15:48:41.309185633 +0100
@@ -2106,8 +2106,9 @@ md_pcrel_from_section (fixS *fixp, segT
int
tc_s390_fix_adjustable (fixS *fixP)
{
- /* Don't adjust references to merge sections. */
- if ((S_GET_SEGMENT (fixP->fx_addsy)->flags & SEC_MERGE) != 0)
+ /* Don't adjust pc-relative references to merge sections. */
+ if (fixP->fx_pcrel
+ && (S_GET_SEGMENT (fixP->fx_addsy)->flags & SEC_MERGE) != 0)
return 0;
/* adjust_reloc_syms doesn't know about the GOT. */
if ( fixP->fx_r_type == BFD_RELOC_16_GOTOFF