Re: [patch 2/2] Perform a namespace lookup at every block level

Sami Wagiaalla
2009-09-04T16:57:02Z

> A recursive search must be performed. This patch provides that
> functionality:
>

That implementation performed redundant searches. This problem is fixed
by this patch.

2009-09-04 Sami Wagiaalla <swagiaal@redhat.com>

* cp-namespace.c (cp_lookup_symbol_namespace): Added search_parent
argument.
* cp-support.h (cp_lookup_symbol_imports): Ditto.
* cp-namespace.c (cp_lookup_symbol_imports): Ditto.
Implement non parent search.
* valops.c (value_maybe_namespace_elt): Updated.

2009-09-04 Sami Wagiaalla <swagiaal@redhat.com>

* gdb.cp/namespace-stress.exp: New test.
* gdb.cp/namespace-stress.cc: New test file.

diff --git a/gdb/cp-namespace.c b/gdb/cp-namespace.c
index 909ec2c..eeaf851 100644
--- a/gdb/cp-namespace.c
+++ b/gdb/cp-namespace.c
@@ -46,7 +46,8 @@ static struct symbol *cp_lookup_symbol_imports (const char *scope,
const char *name,
const char *linkage_name,
const struct block *block,
- const domain_enum domain);
+ const domain_enum domain,
+ const int search_parents);

static struct symbol *cp_lookup_symbol_in_namespace (const char *namespace,
const char *name,
@@ -287,7 +288,7 @@ cp_lookup_symbol_nonlocal (const char *name,
if ( sym != NULL)
return sym;

- return cp_lookup_symbol_namespace(scope, name, linkage_name, block, domain);
+ return cp_lookup_symbol_namespace(scope, name, linkage_name, block, domain, 1);
}

/* Searches for NAME in the current namespace, and by applying relevant import
@@ -299,14 +300,16 @@ cp_lookup_symbol_namespace (const char *scope,
const char *name,
const char *linkage_name,
const struct block *block,
- const domain_enum domain)
+ const domain_enum domain,
+ const int search_parents)
{
struct symbol *sym;

/* Search for name in namespaces imported to this and parent blocks. */
while (block != NULL)
{
- sym = cp_lookup_symbol_imports(scope,name, linkage_name, block, domain);
+ sym = cp_lookup_symbol_imports(scope,name, linkage_name, block, domain,
+ search_parents );

if (sym)
return sym;
@@ -402,17 +405,33 @@ cp_lookup_symbol_in_namespace (const char *namespace,
}

/* Search for NAME by applying all import statements belonging
- to BLOCK which are applicable in SCOPE. */
+ to BLOCK which are applicable in SCOPE.
+ If SEARCH_PARENTS the search will include imports which are applicable in
+ parents of scopes.
+ Example:
+
+ namespace A{
+ using namespace X;
+ namespace B{
+ using namespace Y;
+ }
+ }
+
+ If SCOPE is "A::B" and SEARCH_PARENTS is true the imports of namespaces X
+ and Y will be considered. If SEARCH_PARENTS is false only the import of Y
+ is considered. */

static struct symbol *
cp_lookup_symbol_imports (const char *scope,
const char *name,
const char *linkage_name,
const struct block *block,
- const domain_enum domain)
+ const domain_enum domain,
+ const int search_parents)
{
struct using_direct *current;
struct symbol *sym;
+ int directive_match;

/* First, try to find the symbol in the given namespace. */
sym = cp_lookup_symbol_in_namespace (scope, name, linkage_name, block,
@@ -429,9 +448,15 @@ cp_lookup_symbol_imports (const char *scope,
current = current->next)
{

+ directive_match = search_parents ?
+ strncmp (scope, current->import_dest,
+ strlen(current->import_dest)) == 0 :
+ strcmp (scope, current->import_dest) == 0;
+
/* If the import destination is the current scope or one of its ancestors then
it is applicable. */
- if (strncmp (scope, current->import_dest,
+ if (directive_match &&
+ strncmp (scope, current->import_dest,
strlen(current->import_dest)) == 0 &&
!current->searched )
{
@@ -442,8 +467,8 @@ cp_lookup_symbol_imports (const char *scope,
name,
linkage_name,
block,
- domain);
-
+ domain, 0);
+
current->searched = 0;
if (sym != NULL)
return sym;
diff --git a/gdb/cp-support.h b/gdb/cp-support.h
index c9d53e5..348d7c9 100644
--- a/gdb/cp-support.h
+++ b/gdb/cp-support.h
@@ -108,7 +108,8 @@ extern struct symbol *cp_lookup_symbol_namespace (const char *namespace,
const char *name,
const char *linkage_name,
const struct block *block,
- const domain_enum domain);
+ const domain_enum domain,
+ const int search_parents);

extern struct type *cp_lookup_nested_type (struct type *parent_type,
const char *nested_name,
diff --git a/gdb/testsuite/gdb.cp/namespace-stress.cc b/gdb/testsuite/gdb.cp/namespace-stress.cc
new file mode 100644
index 0000000..f34083e
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/namespace-stress.cc
@@ -0,0 +1,60 @@
+
+namespace A{ int x; }
+namespace B{ int x; }
+namespace C{ int x; }
+namespace D{ int x; }
+namespace E{ int x; }
+namespace F{ int x; }
+namespace G{ int x; }
+namespace H{ int x; }
+namespace I{ int x; }
+namespace J{ int x; }
+namespace K{ int x; }
+namespace L{ int x; }
+namespace M{ int x; }
+namespace N{ int x; }
+namespace O{ int x; }
+namespace P{ int x; }
+namespace Q{ int x; }
+namespace R{ int x; }
+namespace S{ int x; }
+namespace T{ int x; }
+namespace U{ int x; }
+namespace V{ int x; }
+namespace W{ int x; }
+namespace X{ int x; }
+namespace Y{ int x; }
+namespace Z{ int x; }
+
+
+int main(){
+
+ using namespace A;
+ using namespace B;
+ using namespace C;
+ using namespace D;
+ using namespace E;
+ using namespace F;
+ using namespace G;
+ using namespace H;
+ using namespace I;
+ using namespace J;
+ using namespace K;
+ using namespace L;
+ using namespace M;
+ using namespace N;
+ using namespace O;
+ using namespace P;
+ using namespace Q;
+ using namespace R;
+ using namespace S;
+ using namespace T;
+ using namespace U;
+ using namespace V;
+ using namespace W;
+ using namespace X;
+ using namespace Y;
+ using namespace Z;
+
+ return 0;
+}
\ No newline at end of file
diff --git a/gdb/testsuite/gdb.cp/namespace-stress.exp b/gdb/testsuite/gdb.cp/namespace-stress.exp
new file mode 100644
index 0000000..36e0628
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/namespace-stress.exp
@@ -0,0 +1,50 @@
+# Copyright 2008 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/>.
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile namespace-stress
+set srcfile ${testfile}.cc
+set binfile ${objdir}/${subdir}/${testfile}
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
+ untested "Couldn't compile test program"
+ return -1
+}
+
+if [get_compiler_info ${binfile}] {
+ return -1;
+}
+
+# Get things started.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if ![runto_main] then {
+ perror "couldn't run to breakpoint main"
+ continue
+}
+
+############################################
+# Test that the search can fail efficiently
+
+gdb_test "print y" "No symbol \"y\" in current context."
diff --git a/gdb/valops.c b/gdb/valops.c
index 5e5c4ed..3448b4a 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -2754,7 +2754,7 @@ value_maybe_namespace_elt (const struct type *curtype,

sym = cp_lookup_symbol_namespace (namespace_name, name, NULL,
get_selected_block (0),
- VAR_DOMAIN);
+ VAR_DOMAIN,1);

if (sym == NULL)
return NULL;