/*
* Copyright 1993, 2000 Christopher Seiwald.
*
* This file is part of Jam - see jam.c for Copyright information.
*/
/* This file is ALSO:
* (C) Copyright David Abrahams 2001. Permission to copy, use,
* modify, sell and distribute this software is granted provided this
* copyright notice appears in all copies. This software is provided
* "as is" without express or implied warranty, and with no claim as
* to its suitability for any purpose.
*/
# include "jam.h"
# include "lists.h"
# include "parse.h"
# include "scan.h"
# include "newstr.h"
# include "modules.h"
# include "frames.h"
/*
* parse.c - make and destroy parse trees as driven by the parser
*
* 09/07/00 (seiwald) - ref count on PARSE to avoid freeing when used,
* as per Matt Armstrong.
* 09/11/00 (seiwald) - structure reworked to reflect that (*func)()
* returns a LIST *.
*/
static PARSE *yypsave;
void
parse_file( char *f, FRAME* frame )
{
/* Suspend scan of current file */
/* and push this new file in the stream */
yyfparse(f);
/* Now parse each block of rules and execute it. */
/* Execute it outside of the parser so that recursive */
/* calls to yyrun() work (no recursive yyparse's). */
for(;;)
{
PARSE *p;
/* Filled by yyparse() calling parse_save() */
yypsave = 0;
/* If parse error or empty parse, outta here */
if( yyparse() || !( p = yypsave ) )
break;
/* Run the parse tree. */
parse_evaluate( p, frame );
parse_free( p );
}
}
void
parse_save( PARSE *p )
{
yypsave = p;
}
PARSE *
parse_make(
LIST *(*func)( PARSE *p, FRAME *args ),
PARSE *left,
PARSE *right,
PARSE *third,
char *string,
char *string1,
int num )
{
PARSE *p = (PARSE *)malloc( sizeof( PARSE ) );
p->func = func;
p->left = left;
p->right = right;
p->third = third;
p->string = string;
p->string1 = string1;
p->num = num;
p->refs = 1;
p->rulename = 0;
if ( left )
{
p->file = left->file;
p->line = left->line;
}
else
{
yyinput_stream( &p->file, &p->line );
}
return p;
}
void
parse_refer( PARSE *p )
{
++p->refs;
}
void
parse_free( PARSE *p )
{
if( --p->refs )
return;
if( p->string )
freestr( p->string );
if( p->string1 )
freestr( p->string1 );
if( p->left )
parse_free( p->left );
if( p->right )
parse_free( p->right );
if( p->third )
parse_free( p->third );
if ( p->rulename )
freestr( p->rulename );
free( (char *)p );
}
LIST* parse_evaluate( PARSE *p, FRAME* frame )
{
frame->procedure = p;
return (*p->func)(p, frame);
}