/* xa65 - 65xx/65816 cross-assembler and utility suite
 *
 * Copyright (C) 1989-1997 André Fachat (a.fachat@physik.tu-chemnitz.de)
 *
 * Label management module (also see xau.c)
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

/* structs and defs */

#include "xad.h"
#include "xah.h"
#include "xar.h"
#include "xah2.h"
#include "xap.h"
#include "xa.h"

/* externals */

#include "xam.h"
#include "xal.h"

/* exported globals */

char   *lz;

/* local prototypes */

static int b_fget(int*,int);
static int b_ltest(int,int);
static int b_get(int*);
static int b_test(int);
static int ll_def(char *s, int *n, int b, xalabel_t ltype);     
static int b_link(int);

static int b_new(void);

static void cll_init();
static int cll_get();
static void cll_clear();
static int cll_getcur();


static Labtab *ltp;

int l_init(void)
{
	cll_init();
	//unn_init();
	return 0;
}

int ga_lab(void)
{
	return(afile->la.lti);
}

int gm_lab(void)
{
	return(ANZLAB);
}

long gm_labm(void)
{
	return((long)LABMEM);
}

long ga_labm(void)
{
	return(0 /*lni*/);
}

void printllist(fp)
FILE *fp;
{
     int i;
     LabOcc *p;
     char *fname = NULL;

     for(i=0;i<afile->la.lti;i++)
     {
         ltp=afile->la.lt+i;
         fprintf(fp,"%s, 0x%04x, %d, 0x%04x\n",ltp->n,ltp->val,ltp->blk, 
							ltp->afl);
	 p = ltp->occlist;
	 if(p) {
	   while(p) {
	     if(fname != p->fname) {
		if(p!=ltp->occlist) fprintf(fp,"\n");
		fprintf(fp,"    %s",p->fname);
		fname=p->fname;
	     }
	     fprintf(fp," %d", p->line);
	     p=p->next;
	   }
	   fprintf(fp,"\n");
	 }
	 fname=NULL;
     }
}

/**********************************************************************************
 * cheap local labels
 */

static int cll_current = 0;	/* the current cheap local labels block */

/**
 * init the cheap local labels
 */
void cll_init() {
	cll_current = 0;
}

/**
 * get the block number for a new cheap local label block
 */
int cll_get() {
	if (cll_current == 0) {
		cll_current = b_new();
	}
	return cll_current;
}

/**
 * clear the local labels
 */
void cll_clear() {
	cll_current = 0;
}

int cll_getcur() {
	return cll_current;
}

/**********************************************************************************/

/**
 * define a global label (from the "-L" command line parameter)
 */
int lg_set(char *s ) {
	int n, er;

	er = ll_search(s,&n, STD);

	if(er==E_OK) {
	  fprintf(stderr,"Warning: global label doubly defined!\n");
	} else {
          if(!(er=ll_def(s,&n,0, STD))) {
	    return lg_import(n);
	  }
      	}
	return er;
}

/**
 * define a global label (from the .import pseudo opcode))
 * "s" is a pointer to the first label character, end is at \0
 * or at non-alphanumeric/_ char
 */
int lg_import(int n) {
	int er=E_OK;

        ltp=afile->la.lt+n;
        ltp->fl=2;
        ltp->afl=SEG_UNDEF;

	return er;
}

/*
 * re-define a previously undef'd label as globally undefined 
 * (for -U option)
 */
int lg_toglobal(char *s ) {
	int n, er;

//printf("lg_toglobal(%s)\n", s);
	er = ll_search(s,&n, STD);

	if(er==E_OK && ltp->fl != 3) {
		// fonnd, but not yet set as global undef'd label
	        ltp=afile->la.lt+n;
        	ltp->fl=3;
        	ltp->afl=SEG_UNDEF;
		ltp->origblk=ltp->blk;
		ltp->blk=0;
      	}
	return er;
}


/**
 * define a global zeropage label (from the .importzp pseudo opcode))
 * "s" is a pointer to the first label character, end is at \0
 * or at non-alphanumeric/_ char
 */
int lg_importzp(int n) {
	int er=E_OK;

        ltp=afile->la.lt+n;
        ltp->fl=2;
        ltp->afl=SEG_UNDEFZP;

	return er;
}

/**********************************************************************************/
          
int l_def(char *s, int *l, int *x, int *f)
{     
     int n,er,b,i=0;
     xalabel_t cll_fl;
 
     *f=0;	/* flag (given as param) that the label is to be re-defined and the 
		   "label defined error" is to be skipped */
     b=0;	/* block level on block stack, resp. block number */
     n=0;	/* flag, when set, b is absolute block number and not being translated */
     cll_fl=STD;	/* when 0, clear the cheap local label block */

     if(s[0]==':') {
	// ca65 unnamed label
	i++;
        //n++;		/* block number b is absolute */
	//b=unn_get();	/* current (possibly newly allocated) unnamed label block */
	cll_fl = UNNAMED;	// keep the cheap local label block
     } else
     if(s[0]=='-')
     {
          *f+=1;	/* label is being redefined */
          i++;
     } else
     if(s[0]=='@')
     {
	  i++;
          n++;		/* block number b is absolute */
	  b=cll_get();	/* current (possibly newly allocated) cheap label block */
	  cll_fl=CHEAP;	/* do not clear the cll block again... */
     } else
     if(s[0]=='+')
     {
          i++;
          n++;		/* block number b is absolute */
          b=0;		/* global block number */
     } 
     while(s[i]=='&')
     {
	  if (n) b=0;	/* reset block number */
          n=0; 		/* block number is relative */    
          i++;
          b++;		/* one (more) level up the block stack */
     }
     if(!n) {
	  /* translate from block stack level to absolute block number */
          b_fget(&b,b);
     }

     if(cll_fl == STD) {
	/* clear cheap local labels */
	cll_clear();
     }

     if((!isalpha(s[i])) && (s[i]!='_') && !(ca65 && ((cll_fl == UNNAMED) || isdigit(s[i])) ) ) {
	  //printf("SYNTAX cll_fl=%d, i=%d, s[i]=%02x (%c)\n", cll_fl, i, s[i], s[i]);
          er=E_SYNTAX;
     } else
     {
	  er = E_NODEF;
	  if (cll_fl != UNNAMED) {
	          er=ll_search(s+i,&n, cll_fl);
	  }
               
          if(er==E_OK)
          {
	       //printf("l_def OK: cll_fl=%d, i=%d, s=%s\n", cll_fl, i, s);
	       /* we actually found an existing label in the same scope */
               ltp=afile->la.lt+n;
               
               if(*f)
               {
		    /* redefinition of label */
                    *l=ltp->len+i;
               } else
               if(ltp->fl == 0)
               {
		    /* label has not been defined yet, (e.g. pass1 forward ref), so we try to set it. */
                    *l=ltp->len+i;
                    if(b_ltest(ltp->blk,b))
                         er=E_LABDEF;
                    else
                         ltp->blk=b;

               } else
               if(ltp->fl == 3)
               {
		    /* label has been defined as -U undef'd label so far - we need to check */
                    *l=ltp->len+i;
                    if(b_ltest(ltp->origblk,b))
                         er=E_LABDEF;
                    else
                         ltp->blk=b;

               } else
                    er=E_LABDEF;
          } else
          if(er==E_NODEF)
          {

               if(!(er=ll_def(s+i,&n,b, cll_fl) )) /* store the label in the table of labels */
               {
                    ltp=afile->la.lt+n;
                    *l=ltp->len+i;
                    ltp->fl=0;
		    ltp->is_cll=cll_fl;
               }
	       //printf("l_def NODEF: n=%d, s=%s\n", n, ltp->n);
          } 

          *x=n;
     }
     return(er);
}

int l_search(char *s, int *l, int *x, int *v, int *afl)
{
     int n,er,b;
     xalabel_t cll_fl;

     *afl=0;

     /* check cheap local label */
     cll_fl=STD;
     if (s[0]=='@') {
	cll_fl=CHEAP;
	s++;
     } else
     if (s[0]==':') {
	cll_fl = UNNAMED_DEF;
	s++;
     }
    
     er = E_NODEF;
     if (cll_fl != UNNAMED_DEF) { 
     	er=ll_search(s,&n, cll_fl);
     }

//printf("l_search: lab=%s(afl=%d, er=%d, cll_fl=%d, cll_cur=%d)\n",s,*afl,er, cll_fl, cll_getcur());
     if(er==E_OK)
     {
          ltp=afile->la.lt+n;
          *l=ltp->len + ((cll_fl == STD) ? 0 : 1);
          if(ltp->fl == 1)
          {
               l_get(n,v,afl);/*               *v=lt[n].val;*/
               *x=n;
          } else
          {
               er=E_NODEF;
               lz=ltp->n;
               *x=n;
          }
     }
     else
     {
	  if(cll_fl == CHEAP) {
		b=cll_get();
	  } else
	  if(cll_fl == UNNAMED_DEF) {
		b_get(&b); // b=unn_get();
	  } else {
          	b_get(&b);
	  }
	  
          er=ll_def(s,x,b, cll_fl); /* ll_def(...,*v); */

          ltp=afile->la.lt+(*x);
          ltp->is_cll = cll_fl;

          *l=ltp->len + ((cll_fl == STD) ? 0 : 1);
          //*l=ltp->len + cll_fl;

          if(!er) 
          {
               er=E_NODEF;
               lz=ltp->n;   
          }
     }
     return(er);
}

int l_vget(int n, int *v, char **s)
{
     ltp=afile->la.lt+n;
     (*v)=ltp->val;
     *s=ltp->n;
     return 0;
}

void l_addocc(int n, int *v, int *afl) {
     LabOcc *p, *pp;

     (void)v;		/* quench warning */
     (void)afl;		/* quench warning */
     ltp = afile->la.lt+n;
     pp=NULL;
     p = ltp->occlist;
     while(p) {
	if (p->line == filep->fline && p->fname == filep->fname) return;
	pp = p;
	p = p->next;
     }
     p = malloc(sizeof(LabOcc));
     if(!p) {
	fprintf(stderr,"Oops, out of memory!\n");
	exit(1);
     }
     p->next = NULL;
     p->line = filep->fline;
     p->fname = filep->fname;
     if(pp) {
       pp->next = p;
     } else {
       ltp->occlist = p;
     }
}

/* for the list functionality */
char *l_get_name(int n, xalabel_t *is_cll) {
     if (n > afile->la.ltm) {
	fprintf(stderr, "Corrupted structures! n=%d, but max=%d\n", n, afile->la.ltm);
	exit(1);
     }
     ltp=afile->la.lt+n;
     *is_cll = ltp->is_cll;
     return ltp->n;
}

// works on the static(!) ltp "label table pointer"
// also returns the actual index in the table of the current ltp
static int resolve_unnamed() {
	// need to count up/down in the linkd label list for the block
	char *namep = ltp->n;
	int nextp = -1;
	//printf("::: unnamed_def: %s, n=%d\n", namep, n);
	while ((*namep == '+') || (*namep == '-')) {
		char c = *namep;
		nextp = -1;
		if (c == '+') {
			nextp = ltp->blknext;
		} else
		if (c == '-') {
			nextp = ltp->blkprev;
		}
		//printf("::: nextp=%d\n", nextp);
		if (nextp == -1) {
			return -1;	// E_NODEF
		}
		ltp = afile->la.lt+nextp;
		//printf("::: leads to: %s, nextp=%d\n", ltp->n, nextp);
		if (ltp->is_cll == UNNAMED) {
			namep++;
		}
	} 
	return nextp;
}

/* for the listing, esp. html links; returns a pointer to a static buffer, available till next call */
char *l_get_unique_name(int n) {
     static char buf[MAXLINE];
     ltp=afile->la.lt+n;
   
     if (ltp->is_cll == CHEAP || ltp->is_cll == STD) { 
     	sprintf(buf, "%d%c%s", ltp->blk,
		(ltp->is_cll == CHEAP) ? 'C' : '_',
		ltp->n);
     } else
     if (ltp->is_cll == UNNAMED) {
	// definition of unnamed label - name is NULL
	// so use the actual index
	sprintf(buf, "%dU%d", ltp->blk, n);
     } else
     if (ltp->is_cll == UNNAMED_DEF) {
	// we actually need to find the correct label from the "+" and "-" 
	// in the name
	int tmp = resolve_unnamed();
	if (tmp >= 0) {
		sprintf(buf, "%dU%d", ltp->blk, tmp);
	} else {
		sprintf(buf, "__%d", tmp);
	}
     } else {
	buf[0] = 0;	// no value
     }
     return buf;
}

int l_get(int n, int *v, int *afl)
{
     if(crossref) l_addocc(n,v,afl);

     ltp = afile->la.lt+n;

     if (ltp->is_cll == UNNAMED_DEF) {
	int tmp = resolve_unnamed();
	if (tmp == -1) return E_NODEF;
	// now ltp is set to the actual label
     }
     (*v)=ltp->val;
     lz=ltp->n;
     *afl = ltp->afl;
/*printf("l_get('%s'(%d), v=$%04x, afl=%d, fl=%d\n",ltp->n, n, *v, *afl, ltp->fl);*/
     return( (ltp->fl==1) ? E_OK : E_NODEF);
}

void l_set(int n, int v, int afl)
{
     ltp=afile->la.lt+n;
     ltp->val = v;
     ltp->fl = 1;
     ltp->afl = afl;

//printf("l_set('%s'(%d), v=$%04x, afl=%d\n",ltp->n, n, v, afl);
}

static void ll_exblk(int a, int b)
{
     int i;
     for (i=0;i<afile->la.lti;i++)
     {
          ltp=afile->la.lt+i;
          if((!ltp->fl) && (ltp->blk==a))
               ltp->blk=b;
     }
}

/* defines next label, returns new label number in out param n  */     
static int ll_def(char *s, int *n, int b, xalabel_t ltype)          
{
     int j=0,er=E_NOMEM,hash;
     char *s2 = NULL;

//printf("ll_def: s=%s, ltype=%d, no_name=%d\n",s, ltype, no_name);    

     // label table for the file ...
     if(!afile->la.lt) {
	// ... does not exist yet, so malloc it
	afile->la.lti = 0;
	afile->la.ltm = 1000;
	afile->la.lt = malloc(afile->la.ltm * sizeof(Labtab));
     } 
     if(afile->la.lti>=afile->la.ltm) {
	// ... or is at its capacity limit, so realloc it
	afile->la.ltm *= 1.5;
	afile->la.lt = realloc(afile->la.lt, afile->la.ltm * sizeof(Labtab));
     }
     if(!afile->la.lt) {
	fprintf(stderr, "Oops: no memory!\n");
	exit(1);
     }

	  // current pointer in label table
          ltp = afile->la.lt + afile->la.lti;

	  if (ltype != UNNAMED) {
	  	// alloc space and copy over name
		if (ltype == UNNAMED_DEF) {
			// unnamed lables are like ":--" or ":+" with variable length
	  		while((s[j]!='\0') && (s[j]=='+' || s[j]=='-')) j++;
		} else {
			// standard (and cheap) labels are normal text
	  		while((s[j]!='\0') && (isalnum(s[j]) || (s[j]=='_'))) j++;
		}
	  	s2 = malloc(j+1);
	  	if(!s2) {
		fprintf(stderr,"Oops: no memory!\n");
		exit(1);
	  	}
	  	strncpy(s2,s,j);
	  	s2[j]=0;
	  }

	  // init new entry in label table
               er=E_OK;
               ltp->len=j;		// length of label
	       ltp->n = s2;		// name of label (char*)
               ltp->blk=b;		// block number
               ltp->fl=0;
               ltp->afl=0;
               ltp->is_cll=ltype;	// STD, CHEAP, or UNNAMED label
               ltp->occlist=NULL;	
               hash=hashcode(s,j); 	// compute hashcode
               ltp->nextindex=afile->la.hashindex[hash];	// and link in before last entry with same hashcode
               afile->la.hashindex[hash]=afile->la.lti;		// set as start of list for that hashcode

	// TODO: does not work across files!
	ltp->blknext = -1;	// no next block
	ltp->blkprev = b_link( afile->la.lti );	// previous block, linked within block

	if (ltp->blkprev != -1) {
		ltp = afile->la.lt + ltp->blkprev;
		ltp->blknext = afile->la.lti;
	}

               *n=afile->la.lti;	// return the list index for that file in the out parameter n
               afile->la.lti++;		// increase last index in lable table

     return(er);
}

/**
 * search a label name in the label table. Return the label number
 * in "n". Finds only labels that are in a block that is in the current
 * set of blocks (in the block stack)
 *
 * If cll_fl is set, the label is also searched in the local cheap label scope
 *
 * Do not define the label (as is done in l_search()!)
 */
int ll_search(char *s, int *n, xalabel_t cll_fl)          /* search Label in Tabelle ,nr->n    */
{
     int i,j=0,k,er=E_NODEF,hash;

     while(s[j] && (isalnum(s[j])||(s[j]=='_')))  j++;

     hash=hashcode(s,j);
     i=afile->la.hashindex[hash];

     if(i>=afile->la.ltm) return E_NODEF;

     do
     {
          ltp=afile->la.lt+i;
          
          if(j==ltp->len)
          {
               for (k=0;(k<j)&&(ltp->n[k]==s[k]);k++);

	       if (cll_fl == CHEAP) {
			if (ltp->blk == cll_getcur()) {
				er=E_OK;
				break;
			}
	       } else
	       if (cll_fl == UNNAMED) {
			// TODO
	       } else {
//printf("ll_search:match labels %s with %p (%s) from block %d, block check is %d\n", s, ltp, ltp->n, ltp->blk, b_test(ltp->blk));
		       /* check if the found label is in any of the blocks in the
 			  current block stack */
               		if((j==k)&&(!b_test(ltp->blk)))
               		{
		    		/* ok, label found and it is reachable (its block nr is in the current block stack */
                    		er=E_OK;
                   		break;
               		}
	       }
          }

          if(!i)
               break;          

          i=ltp->nextindex;
          
     }while(1);
     
     *n=i;
#if 0
     if(er!=E_OK && er!=E_NODEF)
     {
          fprintf(stderr, "Fehler in ll_search:er=%d\n",er);
          getchar();
     }
#endif
//printf("l_search(%s) returns er=%d, n=%d\n", s, er, *n);

     return(er);
}

int ll_pdef(char *t)
{
	int n;
	
	if(ll_search(t,&n, STD)==E_OK)
	{
		ltp=afile->la.lt+n;
		if(ltp->fl)
			return(E_OK);
	}
	return(E_NODEF);
}

/* 
 * Write out the list of global labels in an o65 file
 */
int l_write(FILE *fp)
{
     int i, afl, n=0;

     if(noglob) {
	fputc(0, fp);
	fputc(0, fp);
	return 0;
     }
     // calculate number of global labels
     for (i=0;i<afile->la.lti;i++) {
        ltp=afile->la.lt+i;
	if((!ltp->blk) && (ltp->fl==1)) {
	  n++;
	}
     }
     // write number of globals to file
     fputc(n&255, fp);
     fputc((n>>8)&255, fp);
     // iterate over labels and write out label
     for (i=0;i<afile->la.lti;i++)
     {
          ltp=afile->la.lt+i;
          if((!ltp->blk) && (ltp->fl==1)) {
	    // write global name
	    fprintf(fp, "%s",ltp->n);
	    fputc(0,fp);

	    // segment byte
	    afl = ltp->afl;
            // hack to switch undef and abs flag from internal to file format 
	    // if asolute of undefined (< SEG_TEXT, i.e. 0 or 1)
	    // then invert bit 0 (0 = absolute)
            if( (afl & (A_FMASK>>8)) < SEG_TEXT) {
		    afl^=1;
	    }
	    // remove residue flags, only write out real segment number
	    // according to o65 file format definition
	    afl = afl & (A_FMASK >> 8);
	    fputc(afl,fp);

	    // value
	    fputc(ltp->val&255, fp);
	    fputc((ltp->val>>8)&255, fp);
	  }
     }
     /*fputc(0,fp);*/
     return 0;
}

/*******************************************************************************************
 * block management code. Here the ".(" and ".)" blocks are maintained. 
 *
 * Blocks are numbered uniquely, every time a new block is opened, the "blk" variable
 * is increased and its number used as block number.
 *
 * The currently open blocks are maintained in a stack (bt[]). The lowest entry is the outermost
 * block number, adding block numbers as blocks are opened. When a block is closed,
 * the block stack is shortened again (bi has the length of the block stack)
 *
 * Methods exist to open new blocks, close a block, and do some checks, e.g. whether
 * a specific block number is contained in the current block stack.
 */
static int bt[MAXBLK];	/* block stack */
static int labind;	/* last allocated label, -1 none yet alloc'd - used for linking to find unnamed labels */
static int bi;		/* length of the block stack (minus 1, i.e. bi[bi] has the innermost block) */
static int blk;		/* current block number for allocation */

int b_init(void)
{
     blk =0;
     bi =0;
     bt[bi]=blk;
     labind=-1;

     return(E_OK);
}     

int b_new(void) 
{
	return ++blk;
}

int b_depth(void)
{
     return bi;
}

int ga_blk(void)
{
	return(blk);
}

/**
 * open a new block scope
 */
int b_open(void)
{
     int er=E_BLKOVR;

     if(bi<MAXBLK-1)
     {
	  bi++;
          bt[bi]=b_new();
          
          er=E_OK;  
     }
     return(er);
}

/**
 * close a block scope
 */
int b_close(void)
{

     if(bi)
     {
          ll_exblk(bt[bi],bt[bi-1]);
          bi--;
     } else {
	  return E_BLOCK;
     }
     cll_clear();
     //unn_clear();
     return(E_OK);
}

/**
 * get the block number of the current innermost block
 */
static int b_get(int *n)
{
     *n=bt[bi];

     return(E_OK);
}

/**
 * returns the block number of the block "i" levels up in the current block stack
 */
static int b_fget(int *n, int i)
{
     if((bi-i)>=0)
          *n=bt[bi-i];
     else
          *n=0;
     return(E_OK);
}

/**
 * tests whether the given block number n is in the current stack of
 * current block numbers bt[]
 */
static int b_test(int n)
{
     int i=bi;

     while( i>=0 && n!=bt[i] )
          i--;

     return( i+1 ? E_OK : E_NOBLK );
}

/**
 * tests whether the given block number "a" is in the 
 */
static int b_ltest(int a, int b)    /* testet ob bt^-1(b) in intervall [0,bt^-1(a)]   */
{
     int i=0,er=E_OK;

     if(a!=b)
     {
          er=E_OK;

          while(i<=bi && b!=bt[i])
          {
               if(bt[i]==a)
               {
                    er=E_NOBLK;
                    break;
               }
               i++;
          }
     }
     return(er);
}

int b_link(int newlab) {
	int tmp = labind;
	//printf("b_link: old was %d, set to %d\n", tmp, newlab);
	labind = newlab;
	return tmp;
}