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build_type_unit_groups and moved closer to only caller and renamed

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* dwarf2read.c (build_type_psymtabs_1): Renamed from
	build_type_unit_groups and moved closer to only caller.  Remove
	arguments.  All references updated.  Remove outdated .gdb_index
	comment.
	(struct tu_abbrev_offset, sort_tu_by_abbrev_offset): Move with
	build_type_psymtabs_1.
This commit is contained in:
Doug Evans 2014-05-19 16:05:01 -07:00
parent c4e54771f8
commit 7305118224
2 changed files with 164 additions and 158 deletions
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9
gdb/ChangeLog
View File

@ -3,6 +3,15 @@
* gdbtypes.c (rank_function): Use XNEWVEC.
* mi/mi-cmds.c (build_table): Use XCNEWVEC.
2014-05-19 Doug Evans <dje@google.com>
* dwarf2read.c (build_type_psymtabs_1): Renamed from
build_type_unit_groups and moved closer to only caller. Remove
arguments. All references updated. Remove outdated .gdb_index
comment.
(struct tu_abbrev_offset, sort_tu_by_abbrev_offset): Move with
build_type_psymtabs_1.
2014-05-19 Doug Evans <dje@google.com>
* dwarf2read.c (struct dwarf2_per_objfile): Delete unused members

313
gdb/dwarf2read.c
View File

@ -5731,162 +5731,6 @@ get_type_unit_group (struct dwarf2_cu *cu, const struct attribute *stmt_list)
return tu_group;
}
/* Struct used to sort TUs by their abbreviation table offset. */
struct tu_abbrev_offset
{
struct signatured_type *sig_type;
sect_offset abbrev_offset;
};
/* Helper routine for build_type_unit_groups, passed to qsort. */
static int
sort_tu_by_abbrev_offset (const void *ap, const void *bp)
{
const struct tu_abbrev_offset * const *a = ap;
const struct tu_abbrev_offset * const *b = bp;
unsigned int aoff = (*a)->abbrev_offset.sect_off;
unsigned int boff = (*b)->abbrev_offset.sect_off;
return (aoff > boff) - (aoff < boff);
}
/* Efficiently read all the type units, calling init_cutu_and_read_dies on
each one passing FUNC,DATA.
The efficiency is because we sort TUs by the abbrev table they use and
only read each abbrev table once. In one program there are 200K TUs
sharing 8K abbrev tables.
The main purpose of this function is to support building the
dwarf2_per_objfile->type_unit_groups table.
TUs typically share the DW_AT_stmt_list of the CU they came from, so we
can collapse the search space by grouping them by stmt_list.
The savings can be significant, in the same program from above the 200K TUs
share 8K stmt_list tables.
FUNC is expected to call get_type_unit_group, which will create the
struct type_unit_group if necessary and add it to
dwarf2_per_objfile->type_unit_groups. */
static void
build_type_unit_groups (die_reader_func_ftype *func, void *data)
{
struct objfile *objfile = dwarf2_per_objfile->objfile;
struct tu_stats *tu_stats = &dwarf2_per_objfile->tu_stats;
struct cleanup *cleanups;
struct abbrev_table *abbrev_table;
sect_offset abbrev_offset;
struct tu_abbrev_offset *sorted_by_abbrev;
struct type_unit_group **iter;
int i;
/* It's up to the caller to not call us multiple times. */
gdb_assert (dwarf2_per_objfile->type_unit_groups == NULL);
if (dwarf2_per_objfile->n_type_units == 0)
return;
/* TUs typically share abbrev tables, and there can be way more TUs than
abbrev tables. Sort by abbrev table to reduce the number of times we
read each abbrev table in.
Alternatives are to punt or to maintain a cache of abbrev tables.
This is simpler and efficient enough for now.
Later we group TUs by their DW_AT_stmt_list value (as this defines the
symtab to use). Typically TUs with the same abbrev offset have the same
stmt_list value too so in practice this should work well.
The basic algorithm here is:
sort TUs by abbrev table
for each TU with same abbrev table:
read abbrev table if first user
read TU top level DIE
[IWBN if DWO skeletons had DW_AT_stmt_list]
call FUNC */
if (dwarf2_read_debug)
fprintf_unfiltered (gdb_stdlog, "Building type unit groups ...\n");
/* Sort in a separate table to maintain the order of all_type_units
for .gdb_index: TU indices directly index all_type_units. */
sorted_by_abbrev = XNEWVEC (struct tu_abbrev_offset,
dwarf2_per_objfile->n_type_units);
for (i = 0; i < dwarf2_per_objfile->n_type_units; ++i)
{
struct signatured_type *sig_type = dwarf2_per_objfile->all_type_units[i];
sorted_by_abbrev[i].sig_type = sig_type;
sorted_by_abbrev[i].abbrev_offset =
read_abbrev_offset (sig_type->per_cu.section,
sig_type->per_cu.offset);
}
cleanups = make_cleanup (xfree, sorted_by_abbrev);
qsort (sorted_by_abbrev, dwarf2_per_objfile->n_type_units,
sizeof (struct tu_abbrev_offset), sort_tu_by_abbrev_offset);
/* Note: In the .gdb_index case, get_type_unit_group may have already been
called any number of times, so we don't reset tu_stats here. */
abbrev_offset.sect_off = ~(unsigned) 0;
abbrev_table = NULL;
make_cleanup (abbrev_table_free_cleanup, &abbrev_table);
for (i = 0; i < dwarf2_per_objfile->n_type_units; ++i)
{
const struct tu_abbrev_offset *tu = &sorted_by_abbrev[i];
/* Switch to the next abbrev table if necessary. */
if (abbrev_table == NULL
|| tu->abbrev_offset.sect_off != abbrev_offset.sect_off)
{
if (abbrev_table != NULL)
{
abbrev_table_free (abbrev_table);
/* Reset to NULL in case abbrev_table_read_table throws
an error: abbrev_table_free_cleanup will get called. */
abbrev_table = NULL;
}
abbrev_offset = tu->abbrev_offset;
abbrev_table =
abbrev_table_read_table (&dwarf2_per_objfile->abbrev,
abbrev_offset);
++tu_stats->nr_uniq_abbrev_tables;
}
init_cutu_and_read_dies (&tu->sig_type->per_cu, abbrev_table, 0, 0,
func, data);
}
/* type_unit_groups can be NULL if there is an error in the debug info.
Just create an empty table so the rest of gdb doesn't have to watch
for this error case. */
if (dwarf2_per_objfile->type_unit_groups == NULL)
{
dwarf2_per_objfile->type_unit_groups =
allocate_type_unit_groups_table ();
}
do_cleanups (cleanups);
if (dwarf2_read_debug)
{
fprintf_unfiltered (gdb_stdlog, "Done building type unit groups:\n");
fprintf_unfiltered (gdb_stdlog, " %d TUs\n",
dwarf2_per_objfile->n_type_units);
fprintf_unfiltered (gdb_stdlog, " %d uniq abbrev tables\n",
tu_stats->nr_uniq_abbrev_tables);
fprintf_unfiltered (gdb_stdlog, " %d symtabs from stmt_list entries\n",
tu_stats->nr_symtabs);
fprintf_unfiltered (gdb_stdlog, " %d symtab sharers\n",
tu_stats->nr_symtab_sharers);
fprintf_unfiltered (gdb_stdlog, " %d type units without a stmt_list\n",
tu_stats->nr_stmt_less_type_units);
}
}
/* Partial symbol tables. */
@ -6144,6 +5988,159 @@ build_type_psymtabs_reader (const struct die_reader_specs *reader,
sort_pst_symbols (objfile, pst);
}
/* Struct used to sort TUs by their abbreviation table offset. */
struct tu_abbrev_offset
{
struct signatured_type *sig_type;
sect_offset abbrev_offset;
};
/* Helper routine for build_type_psymtabs_1, passed to qsort. */
static int
sort_tu_by_abbrev_offset (const void *ap, const void *bp)
{
const struct tu_abbrev_offset * const *a = ap;
const struct tu_abbrev_offset * const *b = bp;
unsigned int aoff = (*a)->abbrev_offset.sect_off;
unsigned int boff = (*b)->abbrev_offset.sect_off;
return (aoff > boff) - (aoff < boff);
}
/* Efficiently read all the type units.
This does the bulk of the work for build_type_psymtabs.
The efficiency is because we sort TUs by the abbrev table they use and
only read each abbrev table once. In one program there are 200K TUs
sharing 8K abbrev tables.
The main purpose of this function is to support building the
dwarf2_per_objfile->type_unit_groups table.
TUs typically share the DW_AT_stmt_list of the CU they came from, so we
can collapse the search space by grouping them by stmt_list.
The savings can be significant, in the same program from above the 200K TUs
share 8K stmt_list tables.
FUNC is expected to call get_type_unit_group, which will create the
struct type_unit_group if necessary and add it to
dwarf2_per_objfile->type_unit_groups. */
static void
build_type_psymtabs_1 (void)
{
struct objfile *objfile = dwarf2_per_objfile->objfile;
struct tu_stats *tu_stats = &dwarf2_per_objfile->tu_stats;
struct cleanup *cleanups;
struct abbrev_table *abbrev_table;
sect_offset abbrev_offset;
struct tu_abbrev_offset *sorted_by_abbrev;
struct type_unit_group **iter;
int i;
/* It's up to the caller to not call us multiple times. */
gdb_assert (dwarf2_per_objfile->type_unit_groups == NULL);
if (dwarf2_per_objfile->n_type_units == 0)
return;
/* TUs typically share abbrev tables, and there can be way more TUs than
abbrev tables. Sort by abbrev table to reduce the number of times we
read each abbrev table in.
Alternatives are to punt or to maintain a cache of abbrev tables.
This is simpler and efficient enough for now.
Later we group TUs by their DW_AT_stmt_list value (as this defines the
symtab to use). Typically TUs with the same abbrev offset have the same
stmt_list value too so in practice this should work well.
The basic algorithm here is:
sort TUs by abbrev table
for each TU with same abbrev table:
read abbrev table if first user
read TU top level DIE
[IWBN if DWO skeletons had DW_AT_stmt_list]
call FUNC */
if (dwarf2_read_debug)
fprintf_unfiltered (gdb_stdlog, "Building type unit groups ...\n");
/* Sort in a separate table to maintain the order of all_type_units
for .gdb_index: TU indices directly index all_type_units. */
sorted_by_abbrev = XNEWVEC (struct tu_abbrev_offset,
dwarf2_per_objfile->n_type_units);
for (i = 0; i < dwarf2_per_objfile->n_type_units; ++i)
{
struct signatured_type *sig_type = dwarf2_per_objfile->all_type_units[i];
sorted_by_abbrev[i].sig_type = sig_type;
sorted_by_abbrev[i].abbrev_offset =
read_abbrev_offset (sig_type->per_cu.section,
sig_type->per_cu.offset);
}
cleanups = make_cleanup (xfree, sorted_by_abbrev);
qsort (sorted_by_abbrev, dwarf2_per_objfile->n_type_units,
sizeof (struct tu_abbrev_offset), sort_tu_by_abbrev_offset);
abbrev_offset.sect_off = ~(unsigned) 0;
abbrev_table = NULL;
make_cleanup (abbrev_table_free_cleanup, &abbrev_table);
for (i = 0; i < dwarf2_per_objfile->n_type_units; ++i)
{
const struct tu_abbrev_offset *tu = &sorted_by_abbrev[i];
/* Switch to the next abbrev table if necessary. */
if (abbrev_table == NULL
|| tu->abbrev_offset.sect_off != abbrev_offset.sect_off)
{
if (abbrev_table != NULL)
{
abbrev_table_free (abbrev_table);
/* Reset to NULL in case abbrev_table_read_table throws
an error: abbrev_table_free_cleanup will get called. */
abbrev_table = NULL;
}
abbrev_offset = tu->abbrev_offset;
abbrev_table =
abbrev_table_read_table (&dwarf2_per_objfile->abbrev,
abbrev_offset);
++tu_stats->nr_uniq_abbrev_tables;
}
init_cutu_and_read_dies (&tu->sig_type->per_cu, abbrev_table, 0, 0,
build_type_psymtabs_reader, NULL);
}
/* type_unit_groups can be NULL if there is an error in the debug info.
Just create an empty table so the rest of gdb doesn't have to watch
for this error case. */
if (dwarf2_per_objfile->type_unit_groups == NULL)
{
dwarf2_per_objfile->type_unit_groups =
allocate_type_unit_groups_table ();
}
do_cleanups (cleanups);
if (dwarf2_read_debug)
{
fprintf_unfiltered (gdb_stdlog, "Done building type unit groups:\n");
fprintf_unfiltered (gdb_stdlog, " %d TUs\n",
dwarf2_per_objfile->n_type_units);
fprintf_unfiltered (gdb_stdlog, " %d uniq abbrev tables\n",
tu_stats->nr_uniq_abbrev_tables);
fprintf_unfiltered (gdb_stdlog, " %d symtabs from stmt_list entries\n",
tu_stats->nr_symtabs);
fprintf_unfiltered (gdb_stdlog, " %d symtab sharers\n",
tu_stats->nr_symtab_sharers);
fprintf_unfiltered (gdb_stdlog, " %d type units without a stmt_list\n",
tu_stats->nr_stmt_less_type_units);
}
}
/* Traversal function for build_type_psymtabs. */
static int
@ -6186,7 +6183,7 @@ build_type_psymtabs (struct objfile *objfile)
if (! create_all_type_units (objfile))
return;
build_type_unit_groups (build_type_psymtabs_reader, NULL);
build_type_psymtabs_1 ();
/* Now that all TUs have been processed we can fill in the dependencies. */
htab_traverse_noresize (dwarf2_per_objfile->type_unit_groups,
@ -14969,7 +14966,7 @@ abbrev_table_free (struct abbrev_table *abbrev_table)
/* Same as abbrev_table_free but as a cleanup.
We pass in a pointer to the pointer to the table so that we can
set the pointer to NULL when we're done. It also simplifies
build_type_unit_groups. */
build_type_psymtabs_1. */
static void
abbrev_table_free_cleanup (void *table_ptr)