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

[Sami Wagiaalla <swagiaal@redhat.com>]

In cases like this

namespace A{
   int ax;
}

namespace B{
   using namespace A;
}

namespace C{
   using namespace B;
}

using namespace A

void foo(){
   C::ax;
}

And this:

namespace{
   namespace{
     in xx;
   }
}

void foo(){
   xx;
}

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

2009-08-14  Sami Wagiaalla  <swagiaal@redhat.com>

	* cp-support.h: Add 'searched' feild to using_direct struct.
	* cp-namespace.c (cp_lookup_symbol_imports): Perform recursive search.
	(cp_add_using): Initialize 'searched' feild.
	(cp_copy_usings): Copy searched feild.



diff --git a/gdb/cp-namespace.c b/gdb/cp-namespace.c
index a0ccd7f..909ec2c 100644
--- a/gdb/cp-namespace.c
+++ b/gdb/cp-namespace.c
@@ -229,6 +229,7 @@ cp_add_using (const char *dest,
    retval->import_src = savestring (src, strlen(src));
    retval->import_dest = savestring (dest, strlen(dest));
    retval->next = next;
+  retval->searched = 0;

    return retval;
  }
@@ -255,6 +256,8 @@ cp_copy_usings (struct using_direct *using,
  				    obstack);
        retval->next = cp_copy_usings (using->next, obstack);

+      retval->searched = using->searched;
+
        xfree (using->import_src);
        xfree (using->import_dest);
        xfree (using);
@@ -408,7 +411,7 @@ cp_lookup_symbol_imports (const char *scope,
                              const struct block *block,
                              const domain_enum domain)
  {
-  const struct using_direct *current;
+  struct using_direct *current;
    struct symbol *sym;

    /* First, try to find the symbol in the given namespace.  */
@@ -428,13 +431,20 @@ cp_lookup_symbol_imports (const char *scope,

        /* If the import destination is the current scope or one of its ancestors then
           it is applicable.  */
-      if (strncmp (scope, current->import_dest, strlen(current->import_dest)) == 0)
+      if (strncmp (scope, current->import_dest,
+                   strlen(current->import_dest)) == 0 &&
+          !current->searched )
  	{
-	  sym = cp_lookup_symbol_in_namespace (current->import_src,
+	  /* Mark this import as searched so that the recursive call does not
+	     search it again.  */
+	  current->searched = 1;
+	  sym = cp_lookup_symbol_namespace (current->import_src,
  					    name,
  					    linkage_name,
  					    block,
  					    domain);
+	
+	  current->searched = 0;
  	  if (sym != NULL)
  	    return sym;
  	}
diff --git a/gdb/cp-support.h b/gdb/cp-support.h
index b5a5c5f..c9d53e5 100644
--- a/gdb/cp-support.h
+++ b/gdb/cp-support.h
@@ -47,6 +47,9 @@ struct using_direct
    char *import_src;
    char *import_dest;
    struct using_direct *next;
+
+  /* Used during import search to temporarly mark this node as searced.  */
+  int searched;
  };


diff --git a/gdb/testsuite/gdb.cp/namespace-recursive.cc b/gdb/testsuite/gdb.cp/namespace-recursive.cc
new file mode 100644
index 0000000..9368ad8
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/namespace-recursive.cc
@@ -0,0 +1,30 @@
+namespace A{
+  int ax = 9;
+}
+
+namespace B{
+  using namespace A;
+}
+
+namespace C{
+  using namespace B;
+}
+
+//---------------
+namespace D{
+  using namespace D;
+  int dx = 99;
+}
+using namespace C;
+
+//---------------
+namespace{
+  namespace{
+    int xx = 999;
+  }
+}
+
+int main(){
+  using namespace D;
+  return ax + dx + xx;
+}
\ No newline at end of file
diff --git a/gdb/testsuite/gdb.cp/namespace-recursive.exp b/gdb/testsuite/gdb.cp/namespace-recursive.exp
new file mode 100644
index 0000000..ebc898f
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/namespace-recursive.exp
@@ -0,0 +1,66 @@
+# 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-recursive
+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 printing from namespace imported into
+# imported namespace
+
+gdb_test "print ax" "= 9"
+
+############################################
+# test that gdb can print without falling
+# into search loop
+
+gdb_test "print dx" "= 99"
+
+############################################
+# test printing from namespace imported into
+# imported namespace where imports are implicit
+# anonymous namespace imports.
+
+gdb_test "print xx" "= 999"
+