/*
 *    (c)Copyright 1992-1997 Obvious Implementations Corp.  Redistribution and
 *    use is allowed under the terms of the DICE-LICENSE FILE,
 *    DICE-LICENSE.TXT.
 */

/*
 *  RELOC.C
 *
 */

#include "defs.h"

Prototype void rel_init(void);
Prototype void ResetReloc(void);
Prototype void AddRelocInfo(short srcHunk, short dstHunk, long size, short flags, long offset, Symbol *sym);
Prototype RelocInfo *FindRelocOffset(long offset, short hunkNo);
Prototype RelocInfo *FindRelocNext(RelocInfo *rel);
Prototype int LoadRelocData(FILE *fi, RelocInfo *r);

List	RelList;
RelocInfo   *RelOffCache;

void
rel_init(void)
{
    NewList(&RelList);
}

void
ResetReloc(void)
{
    RelocInfo *r;

    if (RelList.lh_Head == NULL)
	cerror(EFATAL, "Software Error, ResetReloc");

    while ((r = RemHead(&RelList)) != NULL)
	free(r);
    RelOffCache = NULL;
}

void
AddRelocInfo(short srcHunk, short dstHunk, long size, short flags, long offset, Symbol *sym)
{
    RelocInfo *ri = malloc(sizeof(RelocInfo));
    RelocInfo *r;

    if (ri == NULL)
	cerror(EFATAL, "malloc Failed");

    clrmem(ri, sizeof(RelocInfo));
    ri->ri_Sym = sym;
    ri->ri_SrcHunk = srcHunk;
    ri->ri_DstHunk = dstHunk;
    ri->ri_RelocSize = size;
    ri->ri_RelocFlags= flags;
    ri->ri_SrcOffset = offset;

    for (r = GetTail(&RelList); r; r = GetPred((Node *)&r->ri_Node)) {
	if (r->ri_SrcOffset < ri->ri_SrcOffset)
	    break;
    }
    Insert(&RelList, (Node *)&ri->ri_Node, (Node *)&r->ri_Node);
}

RelocInfo *
FindRelocOffset(long offset, short hunkNo)
{
    RelocInfo *r = RelOffCache;

    if (r == NULL)
	r = GetHead(&RelList);

    while (r && r->ri_SrcOffset >= offset)
	r = GetPred((Node *)&r->ri_Node);

    if (r == NULL)
	r = GetHead(&RelList);

    while (r && r->ri_SrcOffset < offset)
	r = GetSucc((Node *)&r->ri_Node);

    while (r && r->ri_SrcHunk != hunkNo)
	r = GetSucc((Node *)&r->ri_Node);

    if (r)
	RelOffCache = r;

    return(r);
}

RelocInfo *
FindRelocNext(RelocInfo *rel)
{
    RelocInfo *r;

    for (r = GetSucc((Node *)&rel->ri_Node); r && r->ri_SrcHunk != rel->ri_SrcHunk; r = GetSucc((Node *)&r->ri_Node));
    return(r);
}

int
LoadRelocData(FILE *fi, RelocInfo *r)
{
    switch(r->ri_RelocSize) {
    case 0:
	return(0);
    case 1:
	{
	    ubyte c;
	    fread(&c, 1, 1, fi);
	    return(c);
	}
    case 2:
	{
	    uword c;
	    freadl(&c, 2, 1, fi);
	    return(c);
	}
    case 4:
	{
	    ulong c;
	    freadl(&c, 4, 1, fi);
	    return(c);
	}
    default:
	fseek(fi, r->ri_RelocSize, 1);
	return(0);
    }
}