From 3950ffe2a485479f6561c27364d3d7df5a21d124 Mon Sep 17 00:00:00 2001 From: Igor Pashev Date: Sun, 24 Jun 2012 22:28:35 +0000 Subject: Imported Upstream version 93u+ --- src/lib/libast/misc/optctx.c | 70 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 src/lib/libast/misc/optctx.c (limited to 'src/lib/libast/misc/optctx.c') diff --git a/src/lib/libast/misc/optctx.c b/src/lib/libast/misc/optctx.c new file mode 100644 index 0000000..1dbdf71 --- /dev/null +++ b/src/lib/libast/misc/optctx.c @@ -0,0 +1,70 @@ +/*********************************************************************** +* * +* This software is part of the ast package * +* Copyright (c) 1985-2011 AT&T Intellectual Property * +* and is licensed under the * +* Eclipse Public License, Version 1.0 * +* by AT&T Intellectual Property * +* * +* A copy of the License is available at * +* http://www.eclipse.org/org/documents/epl-v10.html * +* (with md5 checksum b35adb5213ca9657e911e9befb180842) * +* * +* Information and Software Systems Research * +* AT&T Research * +* Florham Park NJ * +* * +* Glenn Fowler * +* David Korn * +* Phong Vo * +* * +***********************************************************************/ +#pragma prototyped +/* + * Glenn Fowler + * AT&T Research + * + * _opt_infop_ context control + * + * allocate new context: + * new_context = optctx(0, 0); + * free new context: + * optctx(0, new_context); + * switch to new_context: + * old_context = optctx(new_context, 0); + * switch to old_context and free new_context: + * optctx(old_context, new_context); + */ + +#include + +static Opt_t* freecontext; + +Opt_t* +optctx(Opt_t* p, Opt_t* o) +{ + if (o) + { + if (freecontext) + free(o); + else + freecontext = o; + if (!p) + return 0; + } + if (p) + { + o = _opt_infop_; + _opt_infop_ = p; + } + else + { + if (o = freecontext) + freecontext = 0; + else if (!(o = newof(0, Opt_t, 1, 0))) + return 0; + memset(o, 0, sizeof(Opt_t)); + o->state = _opt_infop_->state; + } + return o; +} -- cgit v1.2.3