This is the mail archive of the
binutils@sourceware.org
mailing list for the binutils project.
[13/21] Fix counting of line-number entries
- From: Richard Sandiford <richards at transitive dot com>
- To: binutils at sourceware dot org
- Date: Tue, 10 Mar 2009 14:36:14 +0000
- Subject: [13/21] Fix counting of line-number entries
- References: <g4y6vd7a4x.fsf@richards-desktop.transitives.com>
This is the bug fix that the previous two patches were leading up to.
The COFF symbol table comes immediately after the line-number table.
_bfd_xcoff_bfd_final_link works out how many line-number entries
each output section needs, records the offsets, and assumes that
the symbol table will start after the last section's line numbers.
It then writes both the line numbers and symbol table in one pass.
Most of the writing is delegated to xcoff_link_input_bfd.
The problem is that xcoff_link_input_bfd decides on the fly whether
to actually output a line number, so the line number counts that
_bfd_xcoff_bfd_final_link used are only worst-case estimates.
This means that the line number table can be shorter than expected,
causing coff_write_object_contents to assume that the symbol table
starts earlier than _bfd_xcoff_bfd_final_link wrote it.
xcoff_link_add_symbols works out exactly how many line numbers
are attached to each symbol, but it does not record per-symbol
values; it simply adds the count to the csect's lineno_count.
xcoff_link_input_bfd then works this value out again, once it
knows whether we're keeping the symbol at all.
I think the cleanest fix is to add a new array that records
per-symbol line counts. We can then count the line numbers
in bfd_size_dynamic_sections, at the same time as deciding
whether to keep a symbol. xcoff_link_input_bfd can then reuse
this information too, rather than having to work it out again.
The obvious disadvantage of this apprach is that it eats more memory,
which is probably why it wasn't taken earlier. However, the only other
way I can see of getting accurate line counts is:
(1) Split out the "how many line numbers does this symbol have?"
logic out of xcoff_link_input_bfd.
(2) Make _bfd_xcoff_final_link do an extra pass over the input bfds,
using this function to collect line-number counts.
This is more complicated, and an extra pass over every input symbol table
and line number table could be rather costly.
OK to install?
Richard
bfd/
* libcoff-in.h (xcoff_tdata): Add a lineno_counts field.
* libcoff.h: Regenerate.
* xcofflink.c (xcoff_link_add_symbols): Record per-symbol
line-number counts in the bfd's lineno_counts field.
Don't keep per-csect line-number counts.
(xcoff_sweep): Don't update per-csect line-number counts.
(bfd_xcoff_size_dynamic_sections): Count the number of line-number
entries in each output section.
(xcoff_link_input_bfd): Get the number of line numbers from
the bfd's lineno_counts field, rather than recalculating it
from scratch. Fix the range check when updating C_BINCL and
C_EINCL symbols.
(_bfd_xcoff_bfd_final_link): Don't count the output line numbers
here. Don't expect csects to have line-number counts.
ld/testsuite/
* ld-powerpc/aix-lineno-1.s, ld-powerpc/aix-lineno-1.txt,
ld-powerpc/aix-lineno-1a.dd, ld-powerpc/aix-lineno-1a.nd,
ld-powerpc/aix-lineno-1b.dd, ld-powerpc/aix-lineno-1b.nd: New tests.
* ld-powerpc/aix52.exp: Run them. Copy aix-lineno-1.txt to tmpdir.
Index: bfd/libcoff-in.h
===================================================================
--- bfd/libcoff-in.h 2009-03-10 13:47:43.000000000 +0000
+++ bfd/libcoff-in.h 2009-03-10 13:48:18.000000000 +0000
@@ -166,6 +166,7 @@ struct xcoff_tdata
/* Used by the XCOFF backend linker. */
asection **csects;
long *debug_indices;
+ unsigned int *lineno_counts;
unsigned int import_file_id;
};
Index: bfd/libcoff.h
===================================================================
--- bfd/libcoff.h 2009-03-10 13:47:43.000000000 +0000
+++ bfd/libcoff.h 2009-03-10 13:48:18.000000000 +0000
@@ -170,6 +170,7 @@ struct xcoff_tdata
/* Used by the XCOFF backend linker. */
asection **csects;
long *debug_indices;
+ unsigned int *lineno_counts;
unsigned int import_file_id;
};
Index: bfd/xcofflink.c
===================================================================
--- bfd/xcofflink.c 2009-03-10 13:47:43.000000000 +0000
+++ bfd/xcofflink.c 2009-03-10 13:48:18.000000000 +0000
@@ -947,6 +947,7 @@ xcoff_link_add_symbols (bfd *abfd, struc
bfd_size_type symcount;
struct xcoff_link_hash_entry **sym_hash;
asection **csect_cache;
+ unsigned int *lineno_counts;
bfd_size_type linesz;
asection *o;
asection *last_real;
@@ -1013,6 +1014,15 @@ #define N_BTSHFT n_btshft
goto error_return;
xcoff_data (abfd)->csects = csect_cache;
+ /* We garbage-collect line-number information on a symbol-by-symbol
+ basis, so we need to have quick access to the number of entries
+ per symbol. */
+ amt = symcount * sizeof (unsigned int);
+ lineno_counts = bfd_zalloc (abfd, amt);
+ if (lineno_counts == NULL && symcount != 0)
+ goto error_return;
+ xcoff_data (abfd)->lineno_counts = lineno_counts;
+
/* While splitting sections into csects, we need to assign the
relocs correctly. The relocs and the csects must both be in
order by VMA within a given section, so we handle this by
@@ -1104,6 +1114,7 @@ #define N_BTSHFT n_btshft
esym += (sym.n_numaux + 1) * symesz;
sym_hash += sym.n_numaux + 1;
csect_cache += sym.n_numaux + 1;
+ lineno_counts += sym.n_numaux + 1;
continue;
}
@@ -1174,7 +1185,7 @@ #define N_BTSHFT n_btshft
if (lin.l_lnno == 0)
break;
}
- csect->lineno_count += (linp - linpstart) / linesz;
+ *lineno_counts = (linp - linpstart) / linesz;
/* The setting of line_filepos will only be
useful if all the line number entries for a
csect are contiguous; this only matters for
@@ -1795,6 +1806,7 @@ #define N_BTSHFT n_btshft
esym += (sym.n_numaux + 1) * symesz;
sym_hash += sym.n_numaux + 1;
csect_cache += sym.n_numaux + 1;
+ lineno_counts += sym.n_numaux + 1;
}
BFD_ASSERT (last_real == NULL || last_real->next == first_csect);
@@ -2602,7 +2614,6 @@ xcoff_sweep (struct bfd_link_info *info)
{
o->size = 0;
o->reloc_count = 0;
- o->lineno_count = 0;
}
}
}
@@ -3396,6 +3407,7 @@ bfd_xcoff_size_dynamic_sections (bfd *ou
bfd_size_type symcount;
long *debug_index;
asection **csectpp;
+ unsigned int *lineno_counts;
struct xcoff_link_hash_entry **sym_hash;
bfd_byte *esym, *esymend;
bfd_size_type symesz;
@@ -3439,6 +3451,7 @@ bfd_xcoff_size_dynamic_sections (bfd *ou
}
csectpp = xcoff_data (sub)->csects;
+ lineno_counts = xcoff_data (sub)->lineno_counts;
sym_hash = obj_xcoff_sym_hashes (sub);
symesz = bfd_coff_symesz (sub);
esym = (bfd_byte *) obj_coff_external_syms (sub);
@@ -3448,6 +3461,7 @@ bfd_xcoff_size_dynamic_sections (bfd *ou
{
struct internal_syment sym;
union internal_auxent aux;
+ asection *csect;
const char *name;
int keep_p;
@@ -3473,8 +3487,9 @@ bfd_xcoff_size_dynamic_sections (bfd *ou
name = NULL;
/* Decide whether to copy this symbol to the output file. */
+ csect = *csectpp;
keep_p = xcoff_keep_symbol_p (info, sub, &sym, &aux,
- *sym_hash, *csectpp, name);
+ *sym_hash, csect, name);
if (keep_p < 0)
return FALSE;
@@ -3497,11 +3512,14 @@ bfd_xcoff_size_dynamic_sections (bfd *ou
}
else
*debug_index = -1;
+ if (*lineno_counts > 0)
+ csect->output_section->lineno_count += *lineno_counts;
}
esym += (sym.n_numaux + 1) * symesz;
csectpp += sym.n_numaux + 1;
sym_hash += sym.n_numaux + 1;
+ lineno_counts += sym.n_numaux + 1;
debug_index += sym.n_numaux + 1;
}
@@ -3590,6 +3608,7 @@ xcoff_link_input_bfd (struct xcoff_final
struct xcoff_link_hash_entry **sym_hash;
struct internal_syment *isymp;
asection **csectpp;
+ unsigned int *lineno_counts;
long *debug_index;
long *indexp;
unsigned long output_index;
@@ -3802,6 +3821,7 @@ #define N_BTSHFT n_btshft
isymp = finfo->internal_syms;
indexp = finfo->sym_indices;
csectpp = xcoff_data (input_bfd)->csects;
+ lineno_counts = xcoff_data (input_bfd)->lineno_counts;
debug_index = xcoff_data (input_bfd)->debug_indices;
outsym = finfo->outsyms;
incls = 0;
@@ -4056,8 +4076,7 @@ #define N_BTSHFT n_btshft
&& ISFCN (isymp->n_type)
&& aux.x_sym.x_fcnary.x_fcn.x_lnnoptr != 0)
{
- if (finfo->info->strip != strip_none
- && finfo->info->strip != strip_some)
+ if (*lineno_counts == 0)
aux.x_sym.x_fcnary.x_fcn.x_lnnoptr = 0;
else
{
@@ -4065,14 +4084,21 @@ #define N_BTSHFT n_btshft
unsigned int enc_count;
bfd_signed_vma linoff;
struct internal_lineno lin;
+ bfd_byte *linp;
+ bfd_byte *linpend;
+ bfd_vma offset;
+ file_ptr pos;
+ bfd_size_type amt;
+ /* Read in the enclosing section's line-number
+ information, if we haven't already. */
o = *csectpp;
enclosing = xcoff_section_data (abfd, o)->enclosing;
enc_count = xcoff_section_data (abfd, o)->lineno_count;
if (oline != enclosing)
{
- file_ptr pos = enclosing->line_filepos;
- bfd_size_type amt = linesz * enc_count;
+ pos = enclosing->line_filepos;
+ amt = linesz * enc_count;
if (bfd_seek (input_bfd, pos, SEEK_SET) != 0
|| (bfd_bread (finfo->linenos, amt, input_bfd)
!= amt))
@@ -4080,114 +4106,83 @@ #define N_BTSHFT n_btshft
oline = enclosing;
}
+ /* Copy across the first entry, adjusting its
+ symbol index. */
linoff = (aux.x_sym.x_fcnary.x_fcn.x_lnnoptr
- enclosing->line_filepos);
-
- bfd_coff_swap_lineno_in (input_bfd,
- (void *) (finfo->linenos + linoff),
- (void *) &lin);
- if (lin.l_lnno != 0
- || ((bfd_size_type) lin.l_addr.l_symndx
- != ((esym
- - isymesz
- - ((bfd_byte *)
- obj_coff_external_syms (input_bfd)))
- / isymesz)))
- aux.x_sym.x_fcnary.x_fcn.x_lnnoptr = 0;
- else
+ linp = finfo->linenos + linoff;
+ bfd_coff_swap_lineno_in (input_bfd, linp, &lin);
+ lin.l_addr.l_symndx = *indexp;
+ bfd_coff_swap_lineno_out (output_bfd, &lin, linp);
+ linp += linesz;
+
+ /* Copy the other entries, adjusting their addresses. */
+ linpend = linp + *lineno_counts * linesz;
+ offset = (o->output_section->vma
+ + o->output_offset
+ - o->vma);
+ for (; linp < linpend; linp += linesz)
{
- bfd_byte *linpend, *linp;
- bfd_vma offset;
- bfd_size_type count;
-
- lin.l_addr.l_symndx = *indexp;
- bfd_coff_swap_lineno_out (output_bfd, (void *) &lin,
- (void *) (finfo->linenos
- + linoff));
-
- linpend = (finfo->linenos
- + enc_count * linesz);
- offset = (o->output_section->vma
- + o->output_offset
- - o->vma);
- for (linp = finfo->linenos + linoff + linesz;
- linp < linpend;
- linp += linesz)
- {
- bfd_coff_swap_lineno_in (input_bfd, (void *) linp,
- (void *) &lin);
- if (lin.l_lnno == 0)
- break;
- lin.l_addr.l_paddr += offset;
- bfd_coff_swap_lineno_out (output_bfd,
- (void *) &lin,
- (void *) linp);
- }
-
- count = (linp - (finfo->linenos + linoff)) / linesz;
+ bfd_coff_swap_lineno_in (input_bfd, linp, &lin);
+ lin.l_addr.l_paddr += offset;
+ bfd_coff_swap_lineno_out (output_bfd, &lin, linp);
+ }
- aux.x_sym.x_fcnary.x_fcn.x_lnnoptr =
- (o->output_section->line_filepos
+ /* Write out the entries we've just processed. */
+ pos = (o->output_section->line_filepos
+ o->output_section->lineno_count * linesz);
+ amt = linesz * *lineno_counts;
+ if (bfd_seek (output_bfd, pos, SEEK_SET) != 0
+ || bfd_bwrite (finfo->linenos + linoff,
+ amt, output_bfd) != amt)
+ return FALSE;
+ o->output_section->lineno_count += *lineno_counts;
- if (bfd_seek (output_bfd,
- aux.x_sym.x_fcnary.x_fcn.x_lnnoptr,
- SEEK_SET) != 0
- || (bfd_bwrite (finfo->linenos + linoff,
- linesz * count, output_bfd)
- != linesz * count))
- return FALSE;
-
- o->output_section->lineno_count += count;
+ /* Record the offset of the symbol's line numbers
+ in the output file. */
+ aux.x_sym.x_fcnary.x_fcn.x_lnnoptr = pos;
- if (incls > 0)
+ if (incls > 0)
+ {
+ struct internal_syment *iisp, *iispend;
+ long *iindp;
+ bfd_byte *oos;
+ bfd_vma range_start, range_end;
+ int iiadd;
+
+ /* Update any C_BINCL or C_EINCL symbols
+ that refer to a line number in the
+ range we just output. */
+ iisp = finfo->internal_syms;
+ iispend = iisp + obj_raw_syment_count (input_bfd);
+ iindp = finfo->sym_indices;
+ oos = finfo->outsyms;
+ range_start = enclosing->line_filepos + linoff;
+ range_end = range_start + *lineno_counts * linesz;
+ while (iisp < iispend)
{
- struct internal_syment *iisp, *iispend;
- long *iindp;
- bfd_byte *oos;
- int iiadd;
-
- /* Update any C_BINCL or C_EINCL symbols
- that refer to a line number in the
- range we just output. */
- iisp = finfo->internal_syms;
- iispend = (iisp
- + obj_raw_syment_count (input_bfd));
- iindp = finfo->sym_indices;
- oos = finfo->outsyms;
- while (iisp < iispend)
+ if (*iindp >= 0
+ && (iisp->n_sclass == C_BINCL
+ || iisp->n_sclass == C_EINCL)
+ && iisp->n_value >= range_start
+ && iisp->n_value < range_end)
{
- if (*iindp >= 0
- && (iisp->n_sclass == C_BINCL
- || iisp->n_sclass == C_EINCL)
- && ((bfd_size_type) iisp->n_value
- >= (bfd_size_type)(enclosing->line_filepos + linoff))
- && ((bfd_size_type) iisp->n_value
- < (enclosing->line_filepos
- + enc_count * linesz)))
- {
- struct internal_syment iis;
-
- bfd_coff_swap_sym_in (output_bfd,
- (void *) oos,
- (void *) &iis);
- iis.n_value =
- (iisp->n_value
- - enclosing->line_filepos
- - linoff
- + aux.x_sym.x_fcnary.x_fcn.x_lnnoptr);
- bfd_coff_swap_sym_out (output_bfd,
- (void *) &iis,
- (void *) oos);
- --incls;
- }
-
- iiadd = 1 + iisp->n_numaux;
- if (*iindp >= 0)
- oos += iiadd * osymesz;
- iisp += iiadd;
- iindp += iiadd;
+ struct internal_syment iis;
+
+ bfd_coff_swap_sym_in (output_bfd, oos, &iis);
+ iis.n_value = (iisp->n_value
+ - range_start
+ + pos);
+ bfd_coff_swap_sym_out (output_bfd,
+ &iis, oos);
+ --incls;
}
+
+ iiadd = 1 + iisp->n_numaux;
+ if (*iindp >= 0)
+ oos += iiadd * osymesz;
+ iisp += iiadd;
+ iindp += iiadd;
}
}
}
@@ -4204,6 +4199,7 @@ #define N_BTSHFT n_btshft
indexp += add;
isymp += add;
csectpp += add;
+ lineno_counts += add;
debug_index += add;
}
@@ -5498,15 +5494,15 @@ _bfd_xcoff_bfd_final_link (bfd *abfd, st
if (finfo.strtab == NULL)
goto error_return;
- /* Count the line number and relocation entries required for the
- output file. Determine a few maximum sizes. */
+ /* Count the relocation entries required for the output file.
+ (We've already counted the line numbers.) Determine a few
+ maximum sizes. */
max_contents_size = 0;
max_lineno_count = 0;
max_reloc_count = 0;
for (o = abfd->sections; o != NULL; o = o->next)
{
o->reloc_count = 0;
- o->lineno_count = 0;
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
if (p->type == bfd_indirect_link_order)
@@ -5521,18 +5517,12 @@ _bfd_xcoff_bfd_final_link (bfd *abfd, st
the linker has decided to not include. */
sec->linker_mark = TRUE;
- if (info->strip == strip_none
- || info->strip == strip_some)
- o->lineno_count += sec->lineno_count;
-
o->reloc_count += sec->reloc_count;
if (sec->rawsize > max_contents_size)
max_contents_size = sec->rawsize;
if (sec->size > max_contents_size)
max_contents_size = sec->size;
- if (sec->lineno_count > max_lineno_count)
- max_lineno_count = sec->lineno_count;
if (coff_section_data (sec->owner, sec) != NULL
&& xcoff_section_data (sec->owner, sec) != NULL
&& (xcoff_section_data (sec->owner, sec)->lineno_count
Index: ld/testsuite/ld-powerpc/aix-lineno-1.s
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1.s 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,25 @@
+ .file "tmpdir/aix-lineno-1.txt"
+ .csect .foo[PR]
+ .function .foo,.foo
+.foo:
+ .bf 1
+ nop
+ .line 2
+ nop
+ .line 3
+ nop
+ .line 4
+ nop
+ .line 5
+ nop
+ .ef 1
+
+ .globl .main
+ .csect .main[PR]
+ .function .main,.main
+.main:
+ .bf 7
+ bl .foo
+ .line 2
+ nop
+ .ef 7
Index: ld/testsuite/ld-powerpc/aix-lineno-1.txt
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1.txt 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,8 @@
+Four
+and
+twenty
+blackbirds
+baked
+in
+a
+pie
Index: ld/testsuite/ld-powerpc/aix-lineno-1a.dd
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1a.dd 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,24 @@
+
+.*
+
+
+Disassembly of section \.text:
+
+0*10000000 <\.foo>:
+Four
+ *10000000: 60 00 00 00 (oril r0,r0,0|nop)
+and
+ *10000004: 60 00 00 00 (oril r0,r0,0|nop)
+twenty
+ *10000008: 60 00 00 00 (oril r0,r0,0|nop)
+blackbirds
+ *1000000c: 60 00 00 00 (oril r0,r0,0|nop)
+baked
+ *10000010: 60 00 00 00 (oril r0,r0,0|nop)
+
+0*10000014 <\.main>:
+in
+a
+ *10000014: 4b ff ff ed bl 10000000 <\.foo>
+pie
+ *10000018: 60 00 00 00 (oril r0,r0,0|nop)
Index: ld/testsuite/ld-powerpc/aix-lineno-1a.nd
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1a.nd 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,8 @@
+0*10000000 t \.bf
+0*10000014 t \.bf
+0*10000014 t \.ef
+0*1000001c t \.ef
+0*10000000 t \.foo
+0*10000000 t \.foo
+0*10000014 t \.main
+0*10000014 T \.main
Index: ld/testsuite/ld-powerpc/aix-lineno-1b.dd
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1b.dd 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,16 @@
+
+.*
+
+
+Disassembly of section \.text:
+
+0*10000000 <\.foo>:
+ *10000000: 60 00 00 00 (oril r0,r0,0|nop)
+ *10000004: 60 00 00 00 (oril r0,r0,0|nop)
+ *10000008: 60 00 00 00 (oril r0,r0,0|nop)
+ *1000000c: 60 00 00 00 (oril r0,r0,0|nop)
+ *10000010: 60 00 00 00 (oril r0,r0,0|nop)
+
+0*10000014 <\.main>:
+ *10000014: 4b ff ff ed bl 10000000 <\.foo>
+ *10000018: 60 00 00 00 (oril r0,r0,0|nop)
Index: ld/testsuite/ld-powerpc/aix-lineno-1b.nd
===================================================================
--- /dev/null 2009-02-06 09:11:03.343159000 +0000
+++ ld/testsuite/ld-powerpc/aix-lineno-1b.nd 2009-03-10 13:48:18.000000000 +0000
@@ -0,0 +1,3 @@
+0*10000000 t \.foo
+0*10000014 t \.main
+0*10000014 T \.main
Index: ld/testsuite/ld-powerpc/aix52.exp
===================================================================
--- ld/testsuite/ld-powerpc/aix52.exp 2009-03-10 13:46:58.000000000 +0000
+++ ld/testsuite/ld-powerpc/aix52.exp 2009-03-10 13:48:18.000000000 +0000
@@ -64,6 +64,10 @@ proc run_aix_test { size name ldopts aso
$output]]
}
+foreach file { "aix-lineno-1.txt" } {
+ remote_upload host "$srcdir/$subdir/$file" "tmpdir/$file"
+}
+
set aix52tests {
{"Absolute branch test 1"
"-shared -bI:aix-abs-branch-1.im -bE:aix-abs-branch-1.ex"
@@ -98,6 +102,16 @@ set aix52tests {
{{objdump {-D -j.text -j.data} aix-glink-1-SIZE.dd}}
"aix-glink-1.so"}
+ {"Line number test 1 (no discards)" "-e.main"
+ "" {aix-lineno-1.s}
+ {{objdump -dS aix-lineno-1a.dd} {nm {} aix-lineno-1a.nd}}
+ "aix-lineno-1a.exe"}
+
+ {"Line number test 1 (discard locals)" "-e.main -x"
+ "" {aix-lineno-1.s}
+ {{objdump -dS aix-lineno-1b.dd} {nm {} aix-lineno-1b.nd}}
+ "aix-lineno-1b.exe"}
+
{"TOC test 1" "-shared -bE:aix-toc-1.ex"
"" {aix-toc-1a.s aix-toc-1b.s}
{{objdump -dr aix-toc-1-SIZE.dd}}