/*
* layout_addresses() is called after all the assembly code has been read and
* fragments, symbols and fixups have been created. This routine sets the
* address of the fragments and symbols. Then it does the fixups of the frags
* and prepares the fixes so relocation entries can be created from them.
*/
void
layout_addresses(
void)
{
struct frchain *frchainP;
fragS *fragP;
relax_addressT slide, tmp;
symbolS *symbolP;
uint32_t nbytes, fill_size, repeat_expression, partial_bytes, layout_pass;
relax_stateT old_fr_type;
int changed;
if(frchain_root == NULL)
return;
/*
* If there is any current frag close it off.
*/
if(frag_now != NULL && frag_now->fr_fix == 0){
frag_now->fr_fix = obstack_next_free(&frags) -
frag_now->fr_literal;
frag_wane(frag_now);
}
/*
* For every section, add a last ".fill 0" frag that will later be used
* as the ending address of that section.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
/*
* We must do the obstack_finish(), so the next object we put on
* obstack frags will not appear to start at the fr_literal of the
* current frag. Also, it ensures that the next object will begin
* on a address that is aligned correctly for the engine that runs
* the assembler.
*/
(void)obstack_finish(&frags);
/*
* Make a fresh frag for the last frag.
*/
frag_now = (fragS *)obstack_alloc(&frags, SIZEOF_STRUCT_FRAG);
memset(frag_now, '\0', SIZEOF_STRUCT_FRAG);
frag_now->fr_next = NULL;
(void)obstack_finish(&frags);
/*
* Append the new frag to current frchain.
*/
frchainP->frch_last->fr_next = frag_now;
frchainP->frch_last = frag_now;
frag_wane(frag_now);
}
/*
* Now set the relative addresses of frags within the section by
* relaxing each section. That is all sections will start at address
* zero and addresses of the frags in that section will increase from
* there.
*
* The debug sections are done last as other section are needed to be
* done first becase debug sections may have line numbers with .loc
* directives in them and their sizes need to be set before processing
* the line number sections. We also do sections that have rs_leb128s
* in them before debug sections but after other sections since they
* are used for things like exception tables and they may be refering to
* sections such that their sizes too must be known first.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & S_ATTR_DEBUG) == S_ATTR_DEBUG)
frchainP->layout_pass = 2;
else if(frchainP->has_rs_leb128s == TRUE)
frchainP->layout_pass = 1;
else
frchainP->layout_pass = 0;
}
for(layout_pass = 0; layout_pass < 3; layout_pass++){
do{
changed = 0;
for(frchainP = frchain_root;
frchainP;
frchainP = frchainP->frch_next){
if(frchainP->layout_pass != layout_pass)
continue;
if((frchainP->frch_section.flags & SECTION_TYPE) ==
S_ZEROFILL)
continue;
/*
* This is done so in case md_estimate_size_before_relax()
* (called by relax_section) wants to make fixSs they are
* for this section.
*/
frchain_now = frchainP;
changed += relax_section(frchainP->frch_root,
frchainP->frch_nsect);
}
}
while(changed != 0);
}
/*
* Now set the absolute addresses of all frags by sliding the frags in
* each non-zerofill section by the address ranges taken up by the
* sections before it.
*/
slide = 0;
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & SECTION_TYPE) == S_ZEROFILL)
continue;
slide = round(slide, 1 << frchainP->frch_section.align);
tmp = frchainP->frch_last->fr_address;
if(slide != 0){
for(fragP = frchainP->frch_root; fragP; fragP = fragP->fr_next){
fragP->fr_address += slide;
}
}
slide += tmp;
}
/*
* Now with the non-zerofill section addresses set set all of the
* addresses of the zerofill sections. Comming in the fr_address is
* the size of the section and going out it is the start address. This
* will make layout_symbols() work out naturally. The only funky thing
* is that section numbers do not end up in address order.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & SECTION_TYPE) != S_ZEROFILL)
continue;
slide = round(slide, 1 << frchainP->frch_section.align);
tmp = frchainP->frch_root->fr_address;
frchainP->frch_root->fr_address = slide;
frchainP->frch_last->fr_address = tmp + slide;
slide += tmp;
}
/*
* Set the symbol addresses based on their frag's address.
* First forward references are handled.
*/
for(symbolP = symbol_rootP; symbolP; symbolP = symbolP->sy_next){
if(symbolP->sy_forward != NULL){
if(symbolP->sy_nlist.n_type & N_STAB)
symbolP->sy_other = symbolP->sy_forward->sy_other;
symbolP->sy_value += symbolP->sy_forward->sy_value +
symbolP->sy_forward->sy_frag->fr_address;
symbolP->sy_forward = 0;
}
}
for(symbolP = symbol_rootP; symbolP; symbolP = symbolP->sy_next){
symbolP->sy_value += symbolP->sy_frag->fr_address;
}
/*
* At this point the addresses of frags now reflect addresses we use in
* the object file and the symbol values are correct.
* Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
* Also converting any machine-dependent frags using md_convert_frag();
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
/*
* This is done so any fixes created by md_convert_frag() are for
* this section.
*/
frchain_now = frchainP;
for(fragP = frchainP->frch_root; fragP; fragP = fragP->fr_next){
switch(fragP->fr_type){
case rs_align:
case rs_org:
old_fr_type = fragP->fr_type;
/* convert this frag to an rs_fill type */
fragP->fr_type = rs_fill;
/*
* Calculate the number of bytes the variable part of the
* the rs_fill frag will need to fill. Then calculate this
* as the fill_size * repeat_expression + partial_bytes.
*/
know(fragP->fr_next != NULL);
nbytes = fragP->fr_next->fr_address -
fragP->fr_address -
fragP->fr_fix;
if(nbytes < 0){
as_warn("rs_org invalid, dot past value by %d bytes",
nbytes);
nbytes = 0;
}
fill_size = fragP->fr_var;
repeat_expression = nbytes / fill_size;
#ifdef I386
/*
* For x86 architecures in sections containing only
* instuctions being padded with nops that are aligned to 16
* bytes or less and are assembled with -dynamic we will
* actually end up padding with the optimal nop sequence.
* Previously there has been the maximum number of bytes
* allocated in the frag to use for this.
*/
if(old_fr_type == rs_align &&
(frchain_now->frch_section.flags &
S_ATTR_PURE_INSTRUCTIONS) != 0 &&
fill_size == 1 &&
fragP->fr_literal[fragP->fr_fix] == (char)0x90 &&
nbytes > 0 && nbytes < 16 &&
flagseen['k'] == TRUE){
i386_align_code(fragP, nbytes);
/*
* The call to i386_align_code() has set the fill_size
* in fragP->fr_var to nbytes. So we set the fr_offset
* to the fill repeat_expression to 1 to match for this
* now an rs_fill type frag.
*/
fragP->fr_offset = 1;
break;
}
#endif /* I386 */
partial_bytes = nbytes - (repeat_expression * fill_size);
/*
* Now set the fr_offset to the fill repeat_expression
* since this is now an rs_fill type. The fr_var is still
* the fill_size.
*/
fragP->fr_offset = repeat_expression;
/*
* For rs_align frags there may be partial_bytes to fill
* with zeros before we can fill with the fill_expression
* of fill_size. When the rs_align frag was created it was
* created with fill_size-1 extra bytes in the fixed part.
*/
if(partial_bytes != 0){
/* moved the fill_expression bytes foward */
memmove(fragP->fr_literal +fragP->fr_fix +partial_bytes,
fragP->fr_literal +fragP->fr_fix,
fragP->fr_var);
/* zero out the partial_bytes */
memset(fragP->fr_literal + fragP->fr_fix,
'\0',
partial_bytes);
/* adjust the fixed part of the frag */
fragP->fr_fix += partial_bytes;
}
break;
case rs_fill:
break;
case rs_machine_dependent:
md_convert_frag(fragP);
/*
* After md_convert_frag, we make the frag into a ".fill 0"
* md_convert_frag() should set up any fixSs and constants
* required.
*/
frag_wane(fragP);
break;
case rs_dwarf2dbg:
dwarf2dbg_convert_frag(fragP);
break;
case rs_leb128:
{
int size;
#ifdef OLD
valueT value = S_GET_VALUE (fragP->fr_symbol);
#else
valueT value;
expressionS *expression;
if(fragP->fr_symbol->expression != NULL){
expression =
(expressionS *)fragP->fr_symbol->expression;
value = 0;
if(expression->X_add_symbol != NULL)
value += expression->X_add_symbol->sy_nlist.n_value;
if(expression->X_subtract_symbol != NULL)
value -=
expression->X_subtract_symbol->sy_nlist.n_value;
value += expression->X_add_number;
}
else{
value = fragP->fr_symbol->sy_nlist.n_value +
fragP->fr_address;
}
#endif
size = output_leb128 (fragP->fr_literal + fragP->fr_fix,
value,
fragP->fr_subtype);
fragP->fr_fix += size;
fragP->fr_type = rs_fill;
fragP->fr_var = 0;
fragP->fr_offset = 0;
fragP->fr_symbol = NULL;
}
break;
default:
BAD_CASE(fragP->fr_type);
break;
}
}
}
/*
* For each section do the fixups for the frags.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
now_seg = frchainP->frch_nsect;
fixup_section(frchainP->frch_fix_root, frchainP->frch_nsect);
}
}
/*
* layout_addresses() is called after all the assembly code has been read and
* fragments, symbols and fixups have been created. This routine sets the
* address of the fragments and symbols. Then it does the fixups of the frags
* and prepares the fixes so relocation entries can be created from them.
*/
void
layout_addresses(
void)
{
struct frchain *frchainP;
fragS *fragP;
relax_addressT slide, tmp;
symbolS *symbolP;
unsigned long nbytes, fill_size, repeat_expression, partial_bytes;
if(frchain_root == NULL)
return;
/*
* If there is any current frag close it off.
*/
if(frag_now != NULL && frag_now->fr_fix == 0){
frag_now->fr_fix = obstack_next_free(&frags) -
frag_now->fr_literal;
frag_wane(frag_now);
}
/*
* For every section, add a last ".fill 0" frag that will later be used
* as the ending address of that section.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
/*
* We must do the obstack_finish(), so the next object we put on
* obstack frags will not appear to start at the fr_literal of the
* current frag. Also, it ensures that the next object will begin
* on a address that is aligned correctly for the engine that runs
* the assembler.
*/
obstack_finish(&frags);
/*
* Make a fresh frag for the last frag.
*/
frag_now = (fragS *)obstack_alloc(&frags, SIZEOF_STRUCT_FRAG);
memset(frag_now, '\0', SIZEOF_STRUCT_FRAG);
frag_now->fr_next = NULL;
obstack_finish(&frags);
/*
* Append the new frag to current frchain.
*/
frchainP->frch_last->fr_next = frag_now;
frchainP->frch_last = frag_now;
frag_wane(frag_now);
}
/*
* Now set the relitive addresses of frags within the section by
* relaxing each section. That is all sections will start at address
* zero and addresses of the frags in that section will increase from
* there.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & SECTION_TYPE) == S_ZEROFILL)
continue;
/*
* This is done so in case md_estimate_size_before_relax() (called
* by relax_section) wants to make fixSs they are for this
* section.
*/
frchain_now = frchainP;
relax_section(frchainP->frch_root, frchainP->frch_nsect);
}
/*
* Now set the absolute addresses of all frags by sliding the frags in
* each non-zerofill section by the address ranges taken up by the
* sections before it.
*/
slide = 0;
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & SECTION_TYPE) == S_ZEROFILL)
continue;
slide = round(slide, 1 << frchainP->frch_section.align);
tmp = frchainP->frch_last->fr_address;
if(slide != 0){
for(fragP = frchainP->frch_root; fragP; fragP = fragP->fr_next){
fragP->fr_address += slide;
}
}
slide += tmp;
}
/*
* Now with the non-zerofill section addresses set set all of the
* addresses of the zerofill sections. Comming in the fr_address is
* the size of the section and going out it is the start address. This
* will make layout_symbols() work out naturally. The only funky thing
* is that section numbers do not end up in address order.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
if((frchainP->frch_section.flags & SECTION_TYPE) != S_ZEROFILL)
continue;
slide = round(slide, 1 << frchainP->frch_section.align);
tmp = frchainP->frch_root->fr_address;
frchainP->frch_root->fr_address = slide;
frchainP->frch_last->fr_address = tmp + slide;
slide += tmp;
}
/*
* Set the symbol addresses based on there frag's address.
* First forward references are handled.
*/
for(symbolP = symbol_rootP; symbolP; symbolP = symbolP->sy_next){
if(symbolP->sy_forward != NULL){
if(symbolP->sy_nlist.n_type & N_STAB)
symbolP->sy_other = symbolP->sy_forward->sy_other;
symbolP->sy_value += symbolP->sy_forward->sy_value +
symbolP->sy_forward->sy_frag->fr_address;
symbolP->sy_forward = 0;
}
}
for(symbolP = symbol_rootP; symbolP; symbolP = symbolP->sy_next){
symbolP->sy_value += symbolP->sy_frag->fr_address;
}
/*
* At this point the addresses of frags now reflect addresses we use in
* the object file and the symbol values are correct.
* Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
* Also converting any machine-dependent frags using md_convert_frag();
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
/*
* This is done so any fixes created by md_convert_frag() are for
* this section.
*/
frchain_now = frchainP;
for(fragP = frchainP->frch_root; fragP; fragP = fragP->fr_next){
switch(fragP->fr_type){
case rs_align:
case rs_org:
/* convert this frag to an rs_fill type */
fragP->fr_type = rs_fill;
/*
* Calculate the number of bytes the variable part of the
* the rs_fill frag will need to fill. Then calculate this
* as the fill_size * repeat_expression + partial_bytes.
*/
know(fragP->fr_next != NULL);
nbytes = fragP->fr_next->fr_address -
fragP->fr_address -
fragP->fr_fix;
if(nbytes < 0){
as_warn("rs_org invalid, dot past value by %ld bytes",
nbytes);
nbytes = 0;
}
fill_size = fragP->fr_var;
repeat_expression = nbytes / fill_size;
partial_bytes = nbytes - (repeat_expression * fill_size);
/*
* Now set the fr_offset to the fill repeat_expression
* since this is now an rs_fill type. The fr_var is still
* the fill_size.
*/
fragP->fr_offset = repeat_expression;
/*
* For rs_align frags there may be partial_bytes to fill
* with zeros before we can fill with the fill_expression
* of fill_size. When the rs_align frag was created it was
* created with fill_size-1 extra bytes in the fixed part.
*/
if(partial_bytes != 0){
/* moved the fill_expression bytes foward */
memmove(fragP->fr_literal +fragP->fr_fix +partial_bytes,
fragP->fr_literal +fragP->fr_fix,
fragP->fr_var);
/* zero out the partial_bytes */
memset(fragP->fr_literal + fragP->fr_fix,
'\0',
partial_bytes);
/* adjust the fixed part of the frag */
fragP->fr_fix += partial_bytes;
}
break;
case rs_fill:
break;
case rs_machine_dependent:
md_convert_frag(fragP);
/*
* After md_convert_frag, we make the frag into a ".fill 0"
* md_convert_frag() should set up any fixSs and constants
* required.
*/
frag_wane(fragP);
break;
default:
BAD_CASE(fragP->fr_type);
break;
}
}
}
/*
* For each section do the fixups for the frags.
*/
for(frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next){
fixup_section(frchainP->frch_fix_root, frchainP->frch_nsect);
}
}
