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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: handles fixups
*
****************************************************************************/
#include "globals.h"
#include "memalloc.h"
#include "parser.h"
#include "fixup.h"
#include "segment.h"
#include "omfspec.h"
#include "myassert.h"
#define GNURELOCS 1
extern struct asym *SegOverride;
int_8 Frame_Type; /* curr fixup frame type: SEG|GRP|EXT|ABS|NONE; see omfspec.h */
uint_16 Frame_Datum; /* curr fixup frame value */
struct fixup *CreateFixup( struct asym *sym, enum fixup_types type, enum fixup_options option )
/*********************************************************************************************/
/*
* called when an instruction operand or a data item is relocatable:
* - Parser.idata_fixup()
* - Parser.memory_operand()
* - branch.process_branch()
* - data.data_item()
* - dbgcv()
* - fpfixup()
* creates a new fixup item and initializes it using symbol <sym>.
* put the correct target offset into the link list when forward reference of
* relocatable is resolved;
* Global vars Frame_Type and Frame_Datum "should" be set.
*/
{
#ifdef DEBUG_OUT
static uint_32 cnt = 0;
#endif
struct fixup *fixup;
fixup = LclAlloc( sizeof( struct fixup ) );
#ifdef TRMEM
fixup->marker = 'XF';
DebugMsg1(("CreateFixup, pass=%u: fix=%p sym=%s\n", Parse_Pass+1, fixup, sym ? sym->name : "NULL" ));
#endif
/* add the fixup to the symbol's linked list (used for backpatch)
* this is done for pass 1 only.
*/
if ( Parse_Pass == PASS_1 ) {
#ifdef DEBUG_OUT
if ( Options.nobackpatch == FALSE )
#endif
if ( sym ) { /* changed v1.96 */
fixup->nextbp = sym->bp_fixup;
sym->bp_fixup = fixup;
}
/* v2.03: in pass one, create a linked list of
* fixup locations for a segment. This is to improve
* backpatching, because it allows to adjust fixup locations
* after a distance has changed from short to near
*/
#ifdef DEBUG_OUT
if ( Options.nobackpatch == FALSE )
#endif
if ( CurrSeg ) {
fixup->nextrlc = CurrSeg->e.seginfo->FixupList.head;
CurrSeg->e.seginfo->FixupList.head = fixup;
}
}
/* initialize locofs member with current offset.
* It's unlikely to be the final location, but sufficiently exact for backpatching.
*/
fixup->locofs = GetCurrOffset();
fixup->offset = 0;
fixup->type = type;
fixup->option = option;
fixup->flags = 0;
fixup->frame_type = Frame_Type; /* this is just a guess */
fixup->frame_datum = Frame_Datum;
fixup->def_seg = CurrSeg; /* may be NULL (END directive) */
fixup->sym = sym;
DebugMsg1(("CreateFixup(sym=%s type=%u, opt=%u) cnt=%" I32_SPEC "X, loc=%" I32_SPEC "Xh\n",
sym ? sym->name : "NULL", type, option, ++cnt, fixup->locofs ));
return( fixup );
}
/* remove a fixup from the segment's fixup queue */
void FreeFixup( struct fixup *fixup )
/***********************************/
{
struct dsym *dir;
struct fixup *fixup2;
if ( Parse_Pass == PASS_1 ) {
dir = fixup->def_seg;
if ( dir ) {
if ( fixup == dir->e.seginfo->FixupList.head ) {
dir->e.seginfo->FixupList.head = fixup->nextrlc;
} else {
for ( fixup2 = dir->e.seginfo->FixupList.head; fixup2; fixup2 = fixup2->nextrlc ) {
if ( fixup2->nextrlc == fixup ) {
fixup2->nextrlc = fixup->nextrlc;
break;
}
}
}
}
}
LclFree( fixup );
}
/*
* Set global variables Frame_Type and Frame_Datum.
* segment override with a symbol (i.e. DGROUP )
* it has been checked in the expression evaluator that the
* symbol has type SYM_SEG/SYM_GRP.
*/
void SetFixupFrame( const struct asym *sym, char ign_grp )
/********************************************************/
{
struct dsym *grp;
if( sym ) {
switch ( sym->state ) {
case SYM_INTERNAL:
case SYM_EXTERNAL:
if( sym->segment != NULL ) {
if( ign_grp == FALSE && ( grp = (struct dsym *)GetGroup( sym ) ) ) {
Frame_Type = FRAME_GRP;
Frame_Datum = grp->e.grpinfo->grp_idx;
} else {
Frame_Type = FRAME_SEG;
Frame_Datum = GetSegIdx( sym->segment );
}
}
break;
case SYM_SEG:
Frame_Type = FRAME_SEG;
Frame_Datum = GetSegIdx( sym->segment );
break;
case SYM_GRP:
Frame_Type = FRAME_GRP;
Frame_Datum = ((struct dsym *)sym)->e.grpinfo->grp_idx;
break;
#ifdef DEBUG_OUT
case SYM_UNDEFINED:
case SYM_STACK:
break;
default:
DebugMsg(("SetFixupFrame(%s): unexpected state=%u\n", sym->name, sym->state ));
/**/myassert( 0 );
break;
#endif
}
}
}
/*
* Store fixup information in segment's fixup linked list.
* please note: forward references for backpatching are written in PASS 1 -
* they no longer exist when store_fixup() is called.
*/
void store_fixup( struct fixup *fixup, struct dsym *seg, int_32 *pdata )
/**********************************************************************/
{
fixup->offset = *pdata;
fixup->nextrlc = NULL;
if ( Options.output_format == OFORMAT_OMF ) {
/* for OMF, the target's offset is stored at the fixup's location. */
if( fixup->type != FIX_SEG && fixup->sym ) {
*pdata += fixup->sym->offset;
}
} else {
#if ELF_SUPPORT
if ( Options.output_format == OFORMAT_ELF ) {
/* v2.07: inline addend for ELF32 only.
* Also, in 64-bit, pdata may be a int_64 pointer (FIX_OFF64)!
*/
#if AMD64_SUPPORT
if ( ModuleInfo.defOfssize == USE64 ) {
#if 0
/* this won't work currently because fixup.offset may have to
* save *(int_64) pdata, but it is 32-bit only!
*/
if ( fixup->type == FIX_OFF64 )
*(int_64 *)pdata = 0;
else
*pdata = 0;
#endif
} else
#endif
if ( fixup->type == FIX_RELOFF32 )
*pdata = -4;
#if GNURELOCS /* v2.04: added */
else if ( fixup->type == FIX_RELOFF16 )
*pdata = -2;
else if ( fixup->type == FIX_RELOFF8 )
*pdata = -1;
#endif
}
#endif
#if DJGPP_SUPPORT
/* Djgpp's COFF variant needs special handling for
* - at least - relative and direct 32-bit offsets.
*/
if ( fixup->sym && ModuleInfo.sub_format == SFORMAT_DJGPP ) {
if ( fixup->type == FIX_RELOFF32 ) { /* probably also for 16-bit */
*pdata -= ( fixup->locofs + 4 );
} else if ( fixup->type == FIX_OFF32 ) {
*pdata += fixup->sym->offset;
fixup->offset += fixup->sym->offset; /* ok? */
fixup->segment = fixup->sym->segment;/* ok? */
}
} else
#endif
/* special handling for assembly time variables needed */
if ( fixup->sym && fixup->sym->variable ) {
/* add symbol's offset to the fixup location and fixup's offset */
*pdata += fixup->sym->offset;
fixup->offset += fixup->sym->offset;
/* and save symbol's segment in fixup */
fixup->segment_var = fixup->sym->segment;
}
#if 0 /* fixup without symbol: this is to be resolved internally! */
else if ( fixup->sym == NULL && fixup->frame == EMPTY ) {
DebugMsg(("store_fixup: fixup skipped, symbol=0, no frame\n" ));
return( NOT_ERROR );
}
#endif
}
if( seg->e.seginfo->FixupList.head == NULL ) {
seg->e.seginfo->FixupList.tail = seg->e.seginfo->FixupList.head = fixup;
} else {
seg->e.seginfo->FixupList.tail->nextrlc = fixup;
seg->e.seginfo->FixupList.tail = fixup;
}
return;
}