Speed up lookup of "type_specific_data"

I noticed that "info locals" on a certain large Ada program was very
slow.  I tracked this down to ada_get_tsd_type expanding nearly every
CU in the program.

This patch fixes the problem by changing this code to use the more
efficient lookup_transparent_type which, unlike the Ada-specific
lookup functions, does not try to find all matching instances.

Note that I first tried fixing this by changing ada_find_any_type, but
this did not work -- I may revisit this approach at some later date.

Also note that the copyright dates on the test files are set that way
because I copied them from another test.

New in v2: the new test failed on the Linaro regression tester.
Looking at the logs, it seems that gdb was picking up a 'value' from
libgnat:

    $1 = {<text variable, no debug info>} 0xf7e227a4 <ada.calendar.formatting.value>

This version renames the local variable in an attempt to work around
this.

v3: In v2, while trying to reproduce the problem locally, I
accidentally forgot to commit one of the changes.
This commit is contained in:
Tom Tromey 2024-02-14 09:48:34 -07:00
parent 12d5d5bfd0
commit 1ab9eefe3c
13 changed files with 200 additions and 20 deletions

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@ -6469,7 +6469,9 @@ ada_get_tsd_type (struct inferior *inf)
struct ada_inferior_data *data = get_ada_inferior_data (inf);
if (data->tsd_type == 0)
data->tsd_type = ada_find_any_type ("ada__tags__type_specific_data");
data->tsd_type
= lookup_transparent_type ("<ada__tags__type_specific_data>",
SEARCH_TYPE_DOMAIN);
return data->tsd_type;
}

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@ -935,9 +935,11 @@ class cplus_language : public language_defn
}
/* See language.h. */
struct type *lookup_transparent_type (const char *name) const override
struct type *lookup_transparent_type (const char *name,
domain_search_flags flags)
const override
{
return cp_lookup_transparent_type (name);
return cp_lookup_transparent_type (name, flags);
}
/* See language.h. */

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@ -1024,10 +1024,10 @@ cp_lookup_nested_symbol (struct type *parent_type,
released version of GCC with such information.) */
struct type *
cp_lookup_transparent_type (const char *name)
cp_lookup_transparent_type (const char *name, domain_search_flags flags)
{
/* First, try the honest way of looking up the definition. */
struct type *t = basic_lookup_transparent_type (name);
struct type *t = basic_lookup_transparent_type (name, flags);
const char *scope;
if (t != NULL)

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@ -161,7 +161,8 @@ extern struct block_symbol
const struct block *block,
const domain_search_flags domain);
struct type *cp_lookup_transparent_type (const char *name);
struct type *cp_lookup_transparent_type (const char *name,
domain_search_flags flags);
/* See description in cp-namespace.c. */

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@ -349,9 +349,10 @@ struct language_defn
/* Find the definition of the type with the given name. */
virtual struct type *lookup_transparent_type (const char *name) const
virtual struct type *lookup_transparent_type (const char *name,
domain_search_flags flags) const
{
return basic_lookup_transparent_type (name);
return basic_lookup_transparent_type (name, flags);
}
/* Find all symbols in the current program space matching NAME in

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@ -2694,9 +2694,9 @@ symbol::matches (domain_search_flags flags) const
/* See symtab.h. */
struct type *
lookup_transparent_type (const char *name)
lookup_transparent_type (const char *name, domain_search_flags flags)
{
return current_language->lookup_transparent_type (name);
return current_language->lookup_transparent_type (name, flags);
}
/* A helper for basic_lookup_transparent_type that interfaces with the
@ -2705,6 +2705,7 @@ lookup_transparent_type (const char *name)
static struct type *
basic_lookup_transparent_type_quick (struct objfile *objfile,
enum block_enum block_index,
domain_search_flags flags,
const lookup_name_info &name)
{
struct compunit_symtab *cust;
@ -2712,14 +2713,14 @@ basic_lookup_transparent_type_quick (struct objfile *objfile,
const struct block *block;
struct symbol *sym;
cust = objfile->lookup_symbol (block_index, name, SEARCH_STRUCT_DOMAIN);
cust = objfile->lookup_symbol (block_index, name, flags);
if (cust == NULL)
return NULL;
bv = cust->blockvector ();
block = bv->block (block_index);
sym = block_find_symbol (block, name, SEARCH_STRUCT_DOMAIN, nullptr);
sym = block_find_symbol (block, name, flags, nullptr);
if (sym == nullptr)
error_in_psymtab_expansion (block_index, name.c_str (), cust);
gdb_assert (!TYPE_IS_OPAQUE (sym->type ()));
@ -2733,6 +2734,7 @@ basic_lookup_transparent_type_quick (struct objfile *objfile,
static struct type *
basic_lookup_transparent_type_1 (struct objfile *objfile,
enum block_enum block_index,
domain_search_flags flags,
const lookup_name_info &name)
{
const struct blockvector *bv;
@ -2743,7 +2745,7 @@ basic_lookup_transparent_type_1 (struct objfile *objfile,
{
bv = cust->blockvector ();
block = bv->block (block_index);
sym = block_find_symbol (block, name, SEARCH_STRUCT_DOMAIN, nullptr);
sym = block_find_symbol (block, name, flags, nullptr);
if (sym != nullptr)
{
gdb_assert (!TYPE_IS_OPAQUE (sym->type ()));
@ -2761,7 +2763,7 @@ basic_lookup_transparent_type_1 (struct objfile *objfile,
global blocks. */
struct type *
basic_lookup_transparent_type (const char *name)
basic_lookup_transparent_type (const char *name, domain_search_flags flags)
{
struct type *t;
@ -2775,7 +2777,7 @@ basic_lookup_transparent_type (const char *name)
for (objfile *objfile : current_program_space->objfiles ())
{
t = basic_lookup_transparent_type_1 (objfile, GLOBAL_BLOCK,
lookup_name);
flags, lookup_name);
if (t)
return t;
}
@ -2783,7 +2785,7 @@ basic_lookup_transparent_type (const char *name)
for (objfile *objfile : current_program_space->objfiles ())
{
t = basic_lookup_transparent_type_quick (objfile, GLOBAL_BLOCK,
lookup_name);
flags, lookup_name);
if (t)
return t;
}
@ -2798,7 +2800,7 @@ basic_lookup_transparent_type (const char *name)
for (objfile *objfile : current_program_space->objfiles ())
{
t = basic_lookup_transparent_type_1 (objfile, STATIC_BLOCK,
lookup_name);
flags, lookup_name);
if (t)
return t;
}
@ -2806,7 +2808,7 @@ basic_lookup_transparent_type (const char *name)
for (objfile *objfile : current_program_space->objfiles ())
{
t = basic_lookup_transparent_type_quick (objfile, STATIC_BLOCK,
lookup_name);
flags, lookup_name);
if (t)
return t;
}

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@ -2307,9 +2307,11 @@ extern void reread_symbols (int from_tty);
The type returned must not be opaque -- i.e., must have at least one field
defined. */
extern struct type *lookup_transparent_type (const char *);
extern struct type *lookup_transparent_type
(const char *name, domain_search_flags flags = SEARCH_STRUCT_DOMAIN);
extern struct type *basic_lookup_transparent_type (const char *);
extern struct type *basic_lookup_transparent_type
(const char *name, domain_search_flags flags = SEARCH_STRUCT_DOMAIN);
/* Macro for name of symbol to indicate a file compiled with gcc. */
#ifndef GCC_COMPILED_FLAG_SYMBOL

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@ -0,0 +1,61 @@
# Copyright 2024 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Check that we can print values of parameters of type 'pointer
# (access) to tagged type'. See PR gdb/22670.
load_lib "ada.exp"
require allow_ada_tests
standard_ada_testfile foo
if {[gdb_compile_ada "${srcfile}" "${binfile}" executable {debug}] != ""} {
return -1
}
clean_restart ${testfile}
set bp_location [gdb_get_line_number "STOP" ${testdir}/foo.adb]
if {![runto "foo.adb:$bp_location"]} {
return
}
gdb_test_no_output "set debug symtab-create 1"
# The idea here is that just a single CU should be expanded while
# searching for the tsd type.
set found_pck 0
set found_pck2 0
gdb_test_multiple "print *the_local_var" "only one CU expanded" -lbl {
-re ".symtab-create. start_subfile: name = \[^,\]*pck\\.adb, name_for_id = \[^\r\n\]*\r\n" {
set found_pck 1
exp_continue
}
-re ".symtab-create. start_subfile: name = \[^,\]*pck2\\.adb, name_for_id = \[^\r\n\]*\r\n" {
set found_pck2 1
exp_continue
}
-re ".symtab-create. start_subfile: name = \[^,\]*, name_for_id = \[^\r\n\]*\r\n" {
exp_continue
}
-re -wrap ".* = \\\(n => $decimal\\\)" {
if {$found_pck + $found_pck2 == 1} {
pass $gdb_test_name
} else {
fail $gdb_test_name
}
}
}

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@ -0,0 +1,23 @@
-- Copyright 2017-2024 Free Software Foundation, Inc.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
with Pck; use Pck;
with Pck2; use Pck2;
procedure Foo is
The_Local_Var : access Top_T2 := new Top_T2'(N => 2);
begin
Inspect (new Top_T'(N => 2)); -- STOP
Inspect2 (The_Local_Var);
end Foo;

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@ -0,0 +1,22 @@
-- Copyright 2017-2024 Free Software Foundation, Inc.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
with Pck2; use Pck2;
package body Pck is
procedure Inspect (Obj: access Top_T'Class) is
begin
null;
end Inspect;
end Pck;

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@ -0,0 +1,21 @@
-- Copyright 2017-2024 Free Software Foundation, Inc.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
package Pck is
type Top_T is tagged record
N : Integer := 1;
end record;
procedure Inspect (Obj: access Top_T'Class);
end Pck;

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@ -0,0 +1,21 @@
-- Copyright 2017-2024 Free Software Foundation, Inc.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
package body Pck2 is
procedure Inspect2 (Obj: access Top_T2'Class) is
begin
null;
end Inspect2;
end Pck2;

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@ -0,0 +1,22 @@
-- Copyright 2017-2024 Free Software Foundation, Inc.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
with Pck; use Pck;
package Pck2 is
type Top_T2 is tagged record
N : Integer := 1;
end record;
procedure Inspect2 (Obj: access Top_T2'Class);
end Pck2;