remote: C++ify thread_item and threads_listing_context

This patch C++ifies the thread_item and threads_listing_context
structures in remote.c.  thread_item::{extra,name} are changed to
std::string.  As a result, there's a bit of awkwardness in
remote_update_thread_list, where we have to xstrdup those strings when
filling the private_thread_info structure.  This is removed in the
following patch, where private_thread_info is also C++ified and its
corresponding fields made std::string too.  The xstrdup then becomes an
std::move.

Other than that there's nothing really special, it's a usual day-to-day
VEC -> vector and char* -> std::string change.  It allows removing a
cleanup in remote_update_thread_list.

Note that an overload of hex2bin that returns a gdb::byte_vector is
added, with corresponding selftests.

gdb/ChangeLog:

	* remote.c (struct thread_item): Add constructor, disable copy
	construction and copy assignment, define default move
	construction and move assignment.
	<extra, name>: Change type to std::string.
	<core>: Initialize.
	<thread_handle>: Make non-pointer.
	(thread_item_t): Remove typedef.
	(DEF_VEC_O(thread_item_t)): Remove.
	(threads_listing_context) <contains_thread>: New method.
	<remove_thread>: New method.
	<items>: Change type to std::vector.
	(clear_threads_listing_context): Remove.
	(threads_listing_context_remove): Remove.
	(remote_newthread_step): Use thread_item constructor, adjust to
	change to std::vector.
	(start_thread): Use thread_item constructor, adjust to change to
	std::vector.
	(end_thread): Adjust to change to std::vector and std::string.
	(remote_get_threads_with_qthreadinfo): Use thread_item
	constructor, adjust to std::vector.
	(remote_update_thread_list): Adjust to change to std::vector and
	std::string, use threads_listing_context methods.
	(remove_child_of_pending_fork): Adjust.
	(remove_new_fork_children): Adjust.
	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add rsp-low-selftests.c.
	(SUBDIR_UNITTESTS_OBS): Add rsp-low-selftests.o.
	* unittests/rsp-low-selftests.c: New file.
	* common/rsp-low.h: Include common/byte-vector.h.
	(hex2bin): New overload.
	* common/rsp-low.c (hex2bin): New overload.

1 files changed, 59 insertions, 0 deletions

diff --git a/gdb/unittests/rsp-low-selftests.c b/gdb/unittests/rsp-low-selftests.c
new file mode 100644
index 0000000..e20fedf
--- /dev/null
+++ b/gdb/unittests/rsp-low-selftests.c
@@ -0,0 +1,59 @@
+/* Unit tests for the rsp-low.c file.
+
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#include "defs.h"
+#include "selftest.h"
+#include "common/rsp-low.h"
+
+namespace selftests {
+namespace rsp_low {
+
+/* Test the variant of hex2bin that returns a byte_vector.  */
+
+static void test_hex2bin_byte_vector ()
+{
+  gdb::byte_vector bv;
+
+  /* Test an empty string.  */
+  bv = hex2bin ("");
+  SELF_CHECK (bv.size () == 0);
+
+  /* Test a well-formated hex string.  */
+  bv = hex2bin ("abcd01");
+  SELF_CHECK (bv.size () == 3);
+  SELF_CHECK (bv[0] == 0xab);
+  SELF_CHECK (bv[1] == 0xcd);
+  SELF_CHECK (bv[2] == 0x01);
+
+  /* Test an odd-length hex string.  */
+  bv = hex2bin ("0123c");
+  SELF_CHECK (bv.size () == 2);
+  SELF_CHECK (bv[0] == 0x01);
+  SELF_CHECK (bv[1] == 0x23);
+}
+
+} /* namespace rsp_low */
+} /* namespace selftests */
+
+void
+_initialize_rsp_low_selftests ()
+{
+  selftests::register_test ("hex2bin_byte_vector",
+			    selftests::rsp_low::test_hex2bin_byte_vector);
+}