Prepare for gnulib update

After the last gnulib import (Dec 2012), gnulib upstream started
replacing mingw's 'struct timeval' with a version with 64-bit time_t,
for POSIX compliance:

 commit f8e84098084b3b53bc6943a5542af1f607ffd477
 Author: Bruno Haible <bruno@clisp.org>
 Date:   Sat Jan 28 18:12:10 2012 +0100
     sys_time: Override 'struct timeval' on some native Windows platforms.

See:

 https://lists.gnu.org/archive/html/bug-gnulib/2012-01/msg00372.html

However, that results in conflicts with native Winsock2's 'select':

select()'s argument
	http://sourceforge.net/p/mingw-w64/mailman/message/29610438/

... and libiberty's timeval-utils.h timeval_add/timeval_sub, at the
least.

We don't really need the POSIX compliance, so this patch prepares us
to simply not use gnulib's 'struct timeval' replacement once a more
recent gnulib is imported, thus preserving the current behavior, by
adding a sys/time.h wrapper header that undefs gnulib's replacements,
and including that everywhere instead.

The SIZE -> OSIZE change is necessary because newer gnulib's
sys/time.h also includes windows.h/winsock2.h, which defines a
conflicting SIZE symbol.

Cross build-tested mingw-w64 32-bit and 64-bit.
Regtested on x86_64 Fedora 20.

gdb/ChangeLog:
2015-08-24  Pedro Alves  <palves@redhat.com>

	* Makefile.in (HFILES_NO_SRCDIR): Add common/gdb_sys_time.h.
	* common/gdb_sys_time.h: New file.
	* event-loop.c: Include gdb_sys_time.h instead of sys/time.h.
	* gdb_select.h: Likewise.
	* gdb_usleep.c: Likewise.
	* maint.c: Likewise.
	* mi/mi-main.c: Likewise.
	* mi/mi-parse.h: Likewise.
	* remote-fileio.c: Likewise.
	* remote-m32r-sdi.c: Likewise.
	* remote.c: Likewise.
	* ser-base.c: Likewise.
	* ser-pipe.c: Likewise.
	* ser-tcp.c: Likewise.
	* ser-unix.c: Likewise.
	* symfile.c: Likewise.
	* symfile.c: Likewise.  Rename OSIZE to SIZE throughout.
	* target-memory.c: Include gdb_sys_time.h instead of sys/time.h.
	* utils.c: Likewise.

gdb/gdbserver/ChangeLog:
2015-08-24  Pedro Alves  <palves@redhat.com>

	* debug.c: Include gdb_sys_time.h instead of sys/time.h.
	* event-loop.c: Likewise.
	* remote-utils.c: Likewise.
	* tracepoint.c: Likewise.

1 files changed, 38 insertions, 0 deletions

diff --git a/gdb/common/gdb_sys_time.h b/gdb/common/gdb_sys_time.h
new file mode 100644
index 00000000000..0f764f888b1
--- /dev/null
+++ b/gdb/common/gdb_sys_time.h
@@ -0,0 +1,38 @@
+/* Copyright (C) 2015 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/>.  */
+
+#ifndef GDB_SYS_TIME_H
+#define GDB_SYS_TIME_H
+
+#include <sys/time.h>
+
+/* On MinGW-w64, gnulib's sys/time.h replaces 'struct timeval' and
+   gettimeofday with versions that support 64-bit time_t, for POSIX
+   compliance.  However, the gettimeofday replacement does not ever
+   return time_t values larger than 31-bit, as it simply returns the
+   system's gettimeofday's (signed) 32-bit result as (signed) 64-bit.
+   Because we don't really need the POSIX compliance, and it ends up
+   causing conflicts with other libraries we use that don't use gnulib
+   and thus work with the native struct timeval, such as Winsock2's
+   native 'select' and libiberty, simply undefine away gnulib's
+   replacements.  */
+#if GNULIB_defined_struct_timeval
+# undef timeval
+# undef gettimeofday
+#endif
+
+#endif /* #ifndef GDB_SYS_TIME_H */