/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1986-2010 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* preprocessor context switch
*
* args op return
* (0,0) free current context 0
* (0,1) save current context current
* (p,0) free context p 0
* (p,1) make p current context previous
*/
#include "pplib.h"
void*
ppcontext(void* context, int flags)
{
struct ppcontext* np = (struct ppcontext*)context;
struct ppcontext* op;
if (flags & 01)
{
if (!(op = pp.context)) op = pp.context = newof(0, struct ppcontext, 1, 0);
memcpy(op, _PP_CONTEXT_BASE_, sizeof(struct ppcontext));
}
else
{
if (!(op = np)) op = (struct ppcontext*)_PP_CONTEXT_BASE_;
if (op->filtab) hashfree(op->filtab);
if (op->prdtab) hashfree(op->prdtab);
if (op->symtab) hashfree(op->symtab);
if (op->date) free(op->date);
if (op->time) free(op->time);
if (np)
{
free(np);
np = 0;
}
memzero(op, sizeof(struct ppcontext));
op = 0;
}
if (np) memcpy(_PP_CONTEXT_BASE_, np, sizeof(struct ppcontext));
return((void*)op);
}