Share gdb/environ.[ch] with gdbserver

We will need access to the environment functions when we share
fork_inferior between GDB and gdbserver, therefore we simply make the
API on gdb/environ.[ch] available on common/.  No extra adjustments
are needed to make it compile on gdbserver.

gdb/ChangeLog:
2017-03-07  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): Replace "environ.c" with
	"common/environ.c".
	(HFILES_NO_SRCDIR): Likewise, for "environ.h".
	* environ.c: Include "common-defs.h" instead of "defs.h.  Moved
	to...
	* common/environ.c: ... here.
	* environ.h: Moved to...
	* common/environ.h: ... here.

gdb/gdbserver/ChangeLog:
2017-03-07  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): Add "common/environ.c".
	(OBJS): Add "common/environ.h".

1 files changed, 49 insertions, 0 deletions

diff --git a/gdb/common/environ.h b/gdb/common/environ.h
new file mode 100644
index 0000000..3ace69e
--- /dev/null
+++ b/gdb/common/environ.h
@@ -0,0 +1,49 @@
+/* Header for environment manipulation library.
+   Copyright (C) 1989-2017 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 !defined (ENVIRON_H)
+#define ENVIRON_H 1
+
+/* We manipulate environments represented as these structures.  */
+
+struct gdb_environ
+  {
+    /* Number of usable slots allocated in VECTOR.
+       VECTOR always has one slot not counted here,
+       to hold the terminating zero.  */
+    int allocated;
+    /* A vector of slots, ALLOCATED + 1 of them.
+       The first few slots contain strings "VAR=VALUE"
+       and the next one contains zero.
+       Then come some unused slots.  */
+    char **vector;
+  };
+
+extern struct gdb_environ *make_environ (void);
+
+extern void free_environ (struct gdb_environ *);
+
+extern void init_environ (struct gdb_environ *);
+
+extern char *get_in_environ (const struct gdb_environ *, const char *);
+
+extern void set_in_environ (struct gdb_environ *, const char *, const char *);
+
+extern void unset_in_environ (struct gdb_environ *, const char *);
+
+extern char **environ_vector (struct gdb_environ *);
+
+#endif /* defined (ENVIRON_H) */