cc65/src/ca65/toklist.c

/*****************************************************************************/
/*                                                                           */
/*			       	   toklist.c				     */
/*                                                                           */
/*		    Token list for the ca65 macroassembler		     */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 1998     Ullrich von Bassewitz                                        */
/*              Wacholderweg 14                                              */
/*              D-70597 Stuttgart                                            */
/* EMail:       uz@musoftware.de                                             */
/*                                                                           */
/*                                                                           */
/* This software is provided 'as-is', without any expressed or implied       */
/* warranty.  In no event will the authors be held liable for any damages    */
/* arising from the use of this software.                                    */
/*                                                                           */
/* Permission is granted to anyone to use this software for any purpose,     */
/* including commercial applications, and to alter it and redistribute it    */
/* freely, subject to the following restrictions:                            */
/*                                                                           */
/* 1. The origin of this software must not be misrepresented; you must not   */
/*    claim that you wrote the original software. If you use this software   */
/*    in a product, an acknowledgment in the product documentation would be  */
/*    appreciated but is not required.                                       */
/* 2. Altered source versions must be plainly marked as such, and must not   */
/*    be misrepresented as being the original software.                      */
/* 3. This notice may not be removed or altered from any source              */
/*    distribution.                                                          */
/*                                                                           */
/*****************************************************************************/



#include <string.h>

#include "../common/xmalloc.h"

#include "istack.h"
#include "scanner.h"
#include "toklist.h"



/*****************************************************************************/
/*     	       	    		     Code	       			     */
/*****************************************************************************/



TokNode* NewTokNode (void)
/* Create and return a token node with the current token value */
{
    TokNode* T;

    /* Allocate memory */
    unsigned Len = TokHasSVal (Tok)? strlen (SVal) : 0;
    T = xmalloc (sizeof (TokNode) + Len);

    /* Initialize the token contents */
    T->Next   	= 0;
    T->Tok	= Tok;
    T->WS	= WS;
    T->IVal	= IVal;
    memcpy (T->SVal, SVal, Len);
    T->SVal [Len] = '\0';

    /* Return the node */
    return T;
}



void FreeTokNode (TokNode* T)
/* Free the given token node */
{
    xfree (T);
}



void TokSet (TokNode* T)
/* Set the scanner token from the given token node */
{
    /* Set the values */
    Tok  = T->Tok;
    WS   = T->WS;
    IVal = T->IVal;
    strcpy (SVal, T->SVal);
}



enum TC TokCmp (const TokNode* T)
/* Compare the token given as parameter against the current token */
{
    if (T->Tok != Tok) {
	/* Different token */
	return tcDifferent;
    }

    /* If the token has string attribute, check it */
    if (TokHasSVal (T->Tok)) {
	if (strcmp  (T->SVal, SVal) != 0) {
     	    return tcSameToken;
	}
    } else if (TokHasIVal (T->Tok)) {
	if (T->IVal != IVal) {
     	    return tcSameToken;
	}
    }

    /* Tokens are identical */
    return tcIdentical;
}



void InitTokList (TokList* T)
/* Initialize a token list structure for later use */
{
    /* Initialize the fields */
    T->Next	= 0;
    T->Root	= 0;
    T->Last	= 0;
    T->Repeat	= 1;
    T->Count 	= 0;
}



TokList* NewTokList (void)
/* Create a new, empty token list */
{
    /* Allocate memory for the list structure */
    TokList* T = xmalloc (sizeof (TokList));

    /* Initialize the fields */
    InitTokList (T);

    /* Return the new list */
    return T;
}



void FreeTokList (TokList* List)
/* Delete the token list including all token nodes */
{
    /* Free the token list */
    TokNode* T = List->Root;
    while (T) {
	TokNode* Tmp = T;
	T = T->Next;
	FreeTokNode (Tmp);
    }

    /* Free the list structure itself */
    xfree (List);
}



void AddCurTok (TokList* List)
/* Add the current token to the token list */
{
    /* Create a token node with the current token value */
    TokNode* T = NewTokNode ();

    /* Insert the node into the list */
    if (List->Root == 0) {
     	List->Root = T;
    } else {
     	List->Last->Next = T;
    }
    List->Last = T;

    /* Count nodes */
    List->Count++;
}



static int ReplayTokList (void* List)
/* Function that gets the next token from a token list and sets it. This
 * function may be used together with the PushInput function from the istack
 * module.
 */
{
    /* Cast the generic pointer to an actual list */
    TokList* L = List;

    /* Set the next token from the list */
    TokSet (L->Last);

    /* If this was the last token, decrement the repeat counter. If it goes
     * zero, delete the list and remove the function from the stack.
     */
    if (L->Last == 0) {
	if (--L->Repeat == 0) {
	    /* Done with this list */
	    FreeTokList (L);
	    PopInput ();
	} else {
	    /* Replay one more time */
	    L->Last = L->Root;
	}
    }

    /* We have a token */
    return 1;
}



void PushTokList (TokList* List, const char* Desc)
/* Push a token list to be used as input for InputFromStack. This includes
 * several initializations needed in the token list structure, so don't use
 * PushInput directly.
 */
{
    /* If the list is empty, just delete it and bail out */
    if (List->Count == 0) {
	FreeTokList (List);
	return;
    }

    /* Reset the last pointer to the first element */
    List->Last = List->Root;

    /* Insert the list specifying our input function */
    PushInput (ReplayTokList, List, Desc);
}