1 /* write.c - emit .o file
3 Copyright (C) 1986, 1987, 1990, 1991, 1992 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GAS is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GAS; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This thing should be set up to do byteordering correctly. But... */
26 #include "output-file.h"
28 /* The NOP_OPCODE is for the alignment fill value.
29 * fill it a nop instruction so that the disassembler does not choke
33 #define NOP_OPCODE 0x00
37 static struct frag *text_frag_root;
38 static struct frag *data_frag_root;
40 static struct frag *text_last_frag; /* Last frag in segment. */
41 static struct frag *data_last_frag; /* Last frag in segment. */
44 static object_headers headers;
46 long string_byte_count;
48 static char *the_object_file;
50 char *next_object_file_charP; /* Tracks object file bytes. */
52 int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE;
54 /* static long length; JF unused */ /* String length, including trailing '\0'. */
59 static int is_dnrange(struct frag *f1, struct frag *f2);
60 static long fixup_segment(fixS *fixP, segT this_segment_type);
61 static relax_addressT relax_align(relax_addressT address, long alignment);
62 void relax_segment(struct frag *segment_frag_root, segT segment_type);
66 static int is_dnrange();
67 static long fixup_segment();
68 static relax_addressT relax_align();
71 #endif /* not __STDC__ */
76 * Create a fixS in obstack 'notes'.
78 fixS *fix_new(frag, where, size, add_symbol, sub_symbol, offset, pcrel
79 #if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE)
83 fragS *frag; /* Which frag? */
84 int where; /* Where in that frag? */
85 short int size; /* 1, 2, or 4 usually. */
86 symbolS *add_symbol; /* X_add_symbol. */
87 symbolS *sub_symbol; /* X_subtract_symbol. */
88 long offset; /* X_add_number. */
89 int pcrel; /* TRUE if PC-relative relocation. */
90 #if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE)
91 int r_type; /* Relocation type */
96 fixP = (fixS *) obstack_alloc(¬es, sizeof(fixS));
99 fixP->fx_where = where;
100 fixP->fx_size = size;
101 fixP->fx_addsy = add_symbol;
102 fixP->fx_subsy = sub_symbol;
103 fixP->fx_offset = offset;
104 fixP->fx_pcrel = pcrel;
105 #if defined(TC_SPARC) || defined(TC_A29K) || defined( NEED_FX_R_TYPE)
106 fixP->fx_r_type = r_type;
108 /* JF these 'cuz of the NS32K stuff */
109 fixP->fx_im_disp = 0;
110 fixP->fx_pcrel_adjust = 0;
112 fixP->fx_bit_fixP = 0;
114 /* usually, we want relocs sorted numerically, but while
115 comparing to older versions of gas that have relocs
116 reverse sorted, it is convenient to have this compile
117 time option. xoxorich. */
119 #ifdef REVERSE_SORT_RELOCS
121 fixP->fx_next = *seg_fix_rootP;
122 *seg_fix_rootP = fixP;
124 #else /* REVERSE_SORT_RELOCS */
126 fixP->fx_next = NULL;
129 (*seg_fix_tailP)->fx_next = fixP;
131 *seg_fix_rootP = fixP;
132 *seg_fix_tailP = fixP;
134 #endif /* REVERSE_SORT_RELOCS */
141 void write_object_file()
143 register struct frchain * frchainP; /* Track along all frchains. */
144 register fragS * fragP; /* Track along all frags. */
145 register struct frchain * next_frchainP;
146 register fragS * * prev_fragPP;
147 /* register char * name; */
148 /* symbolS *symbolP; */
149 /* register symbolS ** symbolPP; */
150 /* register fixS * fixP; JF unused */
151 unsigned int data_siz;
153 long object_file_size;
157 * Under VMS we try to be compatible with VAX-11 "C". Thus, we
158 * call a routine to check for the definition of the procedure
159 * "_main", and if so -- fix it up so that it can be program
162 VMS_Check_For_Main();
165 * After every sub-segment, we fake an ".align ...". This conforms to BSD4.2
166 * brane-damage. We then fake ".fill 0" because that is the kind of frag
167 * that requires least thought. ".align" frags like to have a following
168 * frag since that makes calculating their intended length trivial.
170 #define SUB_SEGMENT_ALIGN (2)
171 for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next) {
174 * Under VAX/VMS, the linker (and PSECT specifications)
175 * take care of correctly aligning the segments.
176 * Doing the alignment here (on initialized data) can
177 * mess up the calculation of global data PSECT sizes.
179 #undef SUB_SEGMENT_ALIGN
180 #define SUB_SEGMENT_ALIGN ((frchainP->frch_seg != SEG_DATA) ? 2 : 0)
182 subseg_new (frchainP->frch_seg, frchainP->frch_subseg);
183 frag_align (SUB_SEGMENT_ALIGN, NOP_OPCODE);
184 /* frag_align will have left a new frag. */
185 /* Use this last frag for an empty ".fill". */
187 * For this segment ...
188 * Create a last frag. Do not leave a "being filled in frag".
190 frag_wane (frag_now);
191 frag_now->fr_fix = 0;
192 know( frag_now->fr_next == NULL );
193 /* know( frags . obstack_c_base == frags . obstack_c_next_free ); */
194 /* Above shows we haven't left a half-completed object on obstack. */
195 } /* walk the frag chain */
198 * From now on, we don't care about sub-segments.
199 * Build one frag chain for each segment. Linked thru fr_next.
200 * We know that there is at least 1 text frchain & at least 1 data frchain.
202 prev_fragPP = &text_frag_root;
203 for (frchainP = frchain_root; frchainP; frchainP = next_frchainP) {
204 know( frchainP->frch_root );
205 * prev_fragPP = frchainP->frch_root;
206 prev_fragPP = & frchainP->frch_last->fr_next;
208 if (((next_frchainP = frchainP->frch_next) == NULL)
209 || next_frchainP == data0_frchainP) {
210 prev_fragPP = & data_frag_root;
212 text_last_frag = frchainP->frch_last;
214 data_last_frag = frchainP->frch_last;
217 } /* walk the frag chain */
220 * We have two segments. If user gave -R flag, then we must put the
221 * data frags into the text segment. Do this before relaxing so
222 * we know to take advantage of -R and make shorter addresses.
224 if (flagseen[ 'R' ]) {
227 text_last_frag->fr_next = data_frag_root;
228 text_last_frag = data_last_frag;
229 data_last_frag = NULL;
230 data_frag_root = NULL;
232 for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next) ;;
233 tmp->fx_next=data_fix_root;
235 text_fix_root=data_fix_root;
239 relax_segment(text_frag_root, SEG_TEXT);
240 relax_segment(data_frag_root, SEG_DATA);
242 * Now the addresses of frags are correct within the segment.
245 know(text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0);
246 H_SET_TEXT_SIZE(&headers, text_last_frag->fr_address);
247 text_last_frag->fr_address = H_GET_TEXT_SIZE(&headers);
250 * Join the 2 segments into 1 huge segment.
251 * To do this, re-compute every rn_address in the SEG_DATA frags.
252 * Then join the data frags after the text frags.
254 * Determine a_data [length of data segment].
256 if (data_frag_root) {
257 register relax_addressT slide;
259 know((text_last_frag->fr_type == rs_fill) && (text_last_frag->fr_offset == 0));
261 H_SET_DATA_SIZE(&headers, data_last_frag->fr_address);
262 data_last_frag->fr_address = H_GET_DATA_SIZE(&headers);
263 slide = H_GET_TEXT_SIZE(&headers); /* & in file of the data segment. */
265 for (fragP = data_frag_root; fragP; fragP = fragP->fr_next) {
266 fragP->fr_address += slide;
267 } /* for each data frag */
269 know(text_last_frag != 0);
270 text_last_frag->fr_next = data_frag_root;
272 H_SET_DATA_SIZE(&headers,0);
276 bss_address_frag.fr_address = (H_GET_TEXT_SIZE(&headers) +
277 H_GET_DATA_SIZE(&headers));
279 H_SET_BSS_SIZE(&headers,local_bss_counter);
283 * Crawl the symbol chain.
285 * For each symbol whose value depends on a frag, take the address of
286 * that frag and subsume it into the value of the symbol.
287 * After this, there is just one way to lookup a symbol value.
288 * Values are left in their final state for object file emission.
289 * We adjust the values of 'L' local symbols, even if we do
290 * not intend to emit them to the object file, because their values
291 * are needed for fix-ups.
293 * Unless we saw a -L flag, remove all symbols that begin with 'L'
294 * from the symbol chain. (They are still pointed to by the fixes.)
296 * Count the remaining symbols.
297 * Assign a symbol number to each symbol.
298 * Count the number of string-table chars we will emit.
299 * Put this info into the headers as appropriate.
302 know(zero_address_frag.fr_address == 0);
303 string_byte_count = sizeof(string_byte_count);
305 obj_crawl_symbol_chain(&headers);
307 if (string_byte_count == sizeof(string_byte_count)) {
308 string_byte_count = 0;
309 } /* if no strings, then no count. */
311 H_SET_STRING_SIZE(&headers, string_byte_count);
314 * Addresses of frags now reflect addresses we use in the object file.
315 * Symbol values are correct.
316 * Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
317 * Also converting any machine-dependent frags using md_convert_frag();
319 subseg_change(SEG_TEXT, 0);
321 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) {
322 switch (fragP->fr_type) {
325 fragP->fr_type = rs_fill;
326 know(fragP->fr_var == 1);
327 know(fragP->fr_next != NULL);
329 fragP->fr_offset = (fragP->fr_next->fr_address
337 case rs_machine_dependent:
338 md_convert_frag(&headers, fragP);
340 know((fragP->fr_next == NULL) || ((fragP->fr_next->fr_address - fragP->fr_address) == fragP->fr_fix));
343 * After md_convert_frag, we make the frag into a ".space 0".
344 * Md_convert_frag() should set up any fixSs and constants
350 #ifndef WORKING_DOT_WORD
351 case rs_broken_word: {
352 struct broken_word *lie;
353 extern md_short_jump_size;
354 extern md_long_jump_size;
356 if (fragP->fr_subtype) {
357 fragP->fr_fix+=md_short_jump_size;
358 for (lie=(struct broken_word *)(fragP->fr_symbol);lie && lie->dispfrag==fragP;lie=lie->next_broken_word)
360 fragP->fr_fix+=md_long_jump_size;
368 BAD_CASE( fragP->fr_type );
370 } /* switch (fr_type) */
372 know((fragP->fr_next == NULL) || ((fragP->fr_next->fr_address - fragP->fr_address) == (fragP->fr_fix + (fragP->fr_offset * fragP->fr_var))));
373 } /* for each frag. */
375 #ifndef WORKING_DOT_WORD
377 struct broken_word *lie;
378 struct broken_word **prevP;
380 prevP= &broken_words;
381 for (lie=broken_words; lie; lie=lie->next_broken_word)
384 fix_new_ns32k(lie->frag,
385 lie->word_goes_here - lie->frag->fr_literal,
391 #elif defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE)
392 fix_new( lie->frag, lie->word_goes_here - lie->frag->fr_literal,
394 lie->sub, lie->addnum,
397 fix_new( lie->frag, lie->word_goes_here - lie->frag->fr_literal,
399 lie->sub, lie->addnum,
402 #endif /* TC_NS32K */
403 /* md_number_to_chars(lie->word_goes_here,
404 S_GET_VALUE(lie->add)
406 - S_GET_VALUE(lie->sub),
408 *prevP=lie->next_broken_word;
410 prevP= &(lie->next_broken_word);
412 for (lie=broken_words;lie;) {
413 struct broken_word *untruth;
421 extern md_short_jump_size;
422 extern md_long_jump_size;
426 /* Find out how many broken_words go here */
428 for (untruth=lie;untruth && untruth->dispfrag==fragP;untruth=untruth->next_broken_word)
429 if (untruth->added==1)
432 table_ptr=lie->dispfrag->fr_opcode;
433 table_addr=lie->dispfrag->fr_address+(table_ptr - lie->dispfrag->fr_literal);
434 /* Create the jump around the long jumps */
435 /* This is a short jump from table_ptr+0 to table_ptr+n*long_jump_size */
436 from_addr=table_addr;
437 to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
438 md_create_short_jump(table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
439 table_ptr+=md_short_jump_size;
440 table_addr+=md_short_jump_size;
442 for (m=0;lie && lie->dispfrag==fragP;m++,lie=lie->next_broken_word) {
445 /* Patch the jump table */
446 /* This is the offset from ??? to table_ptr+0 */
448 - S_GET_VALUE(lie->sub);
449 md_number_to_chars(lie->word_goes_here,to_addr,2);
450 for (untruth=lie->next_broken_word;untruth && untruth->dispfrag==fragP;untruth=untruth->next_broken_word) {
451 if (untruth->use_jump==lie)
452 md_number_to_chars(untruth->word_goes_here,to_addr,2);
455 /* Install the long jump */
456 /* this is a long jump from table_ptr+0 to the final target */
457 from_addr=table_addr;
458 to_addr=S_GET_VALUE(lie->add) + lie->addnum;
459 md_create_long_jump(table_ptr,from_addr,to_addr,lie->dispfrag,lie->add);
460 table_ptr+=md_long_jump_size;
461 table_addr+=md_long_jump_size;
465 #endif /* not WORKING_DOT_WORD */
470 * Scan every FixS performing fixups. We had to wait until now to do
471 * this because md_convert_frag() may have made some fixSs.
474 H_SET_RELOCATION_SIZE(&headers,
475 md_reloc_size * fixup_segment(text_fix_root, SEG_TEXT),
476 md_reloc_size * fixup_segment(data_fix_root, SEG_DATA));
479 /* FIXME move this stuff into the pre-write-hook */
480 H_SET_MAGIC_NUMBER(&headers, magic_number_for_object_file);
481 H_SET_ENTRY_POINT(&headers, 0);
483 obj_pre_write_hook(&headers); /* extra coff stuff */
484 if ((had_warnings() && flagseen['Z'])
485 || had_errors() > 0) {
487 as_warn("%d error%s, %d warning%s, generating bad object file.\n",
488 had_errors(), had_errors() == 1 ? "" : "s",
489 had_warnings(), had_warnings() == 1 ? "" : "s");
491 as_fatal("%d error%s, %d warning%s, no object file generated.\n",
492 had_errors(), had_errors() == 1 ? "" : "s",
493 had_warnings(), had_warnings() == 1 ? "" : "s");
494 } /* on want output */
495 } /* on error condition */
497 object_file_size = H_GET_FILE_SIZE(&headers);
498 next_object_file_charP = the_object_file = xmalloc(object_file_size);
500 output_file_create(out_file_name);
502 obj_header_append(&next_object_file_charP, &headers);
504 know((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE(&headers));
509 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) {
511 register char *fill_literal;
512 register long fill_size;
514 know(fragP->fr_type == rs_fill);
515 append(&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix);
516 fill_literal = fragP->fr_literal + fragP->fr_fix;
517 fill_size = fragP->fr_var;
518 know(fragP->fr_offset >= 0);
520 for (count = fragP->fr_offset; count; count--) {
521 append(&next_object_file_charP, fill_literal, (unsigned long) fill_size);
524 } /* for each code frag. */
526 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers)));
531 obj_emit_relocations(&next_object_file_charP, text_fix_root, (relax_addressT)0);
532 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers) + H_GET_TEXT_RELOCATION_SIZE(&headers)));
534 /* Make addresses in data relocation directives relative to beginning of
535 * first data fragment, not end of last text fragment: alignment of the
536 * start of the data segment may place a gap between the segments.
538 obj_emit_relocations(&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address);
540 obj_emit_relocations(&next_object_file_charP, data_fix_root, text_last_frag->fr_address);
543 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers) + H_GET_TEXT_RELOCATION_SIZE(&headers) + H_GET_DATA_RELOCATION_SIZE(&headers)));
546 * Emit line number entries.
548 OBJ_EMIT_LINENO(&next_object_file_charP, lineno_rootP, the_object_file);
549 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers) + H_GET_TEXT_RELOCATION_SIZE(&headers) + H_GET_DATA_RELOCATION_SIZE(&headers) + H_GET_LINENO_SIZE(&headers)));
554 obj_emit_symbols(&next_object_file_charP, symbol_rootP);
555 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers) + H_GET_TEXT_RELOCATION_SIZE(&headers) + H_GET_DATA_RELOCATION_SIZE(&headers) + H_GET_LINENO_SIZE(&headers) + H_GET_SYMBOL_TABLE_SIZE(&headers)));
561 if (string_byte_count > 0) {
562 obj_emit_strings(&next_object_file_charP);
563 } /* only if we have a string table */
565 /* know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers) + H_GET_TEXT_RELOCATION_SIZE(&headers) + H_GET_DATA_RELOCATION_SIZE(&headers) + H_GET_LINENO_SIZE(&headers) + H_GET_SYMBOL_TABLE_SIZE(&headers) + H_GET_STRING_SIZE(&headers)));
567 /* know(next_object_file_charP == the_object_file + object_file_size);*/
570 bfd_seek(stdoutput, 0, 0);
571 bfd_write(the_object_file, 1, object_file_size, stdoutput);
574 /* Write the data to the file */
575 output_file_append(the_object_file,object_file_size,out_file_name);
578 output_file_close(out_file_name);
579 } /* non vms output */
582 * Now do the VMS-dependent part of writing the object file
584 VMS_write_object_file(text_siz, data_siz, text_frag_root, data_frag_root);
586 } /* write_object_file() */
593 * Now we have a segment, not a crowd of sub-segments, we can make fr_address
598 * After this, all frags in this segment have addresses that are correct
599 * within the segment. Since segments live in different file addresses,
600 * these frag addresses may not be the same as final object-file addresses.
605 void relax_segment(segment_frag_root, segment)
606 struct frag * segment_frag_root;
607 segT segment; /* SEG_DATA or SEG_TEXT */
609 register struct frag * fragP;
610 register relax_addressT address;
611 /* register relax_addressT old_address; JF unused */
612 /* register relax_addressT new_address; JF unused */
613 #ifndef MANY_SEGMENTS
614 know(segment == SEG_DATA || segment == SEG_TEXT);
616 /* In case md_estimate_size_before_relax() wants to make fixSs. */
617 subseg_change(segment, 0);
620 * For each frag in segment: count and store (a 1st guess of) fr_address.
623 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) {
624 fragP->fr_address = address;
625 address += fragP->fr_fix;
627 switch (fragP->fr_type) {
629 address += fragP->fr_offset * fragP->fr_var ;
633 address += relax_align(address, fragP->fr_offset);
638 * Assume .org is nugatory. It will grow with 1st relax.
642 case rs_machine_dependent:
643 address += md_estimate_size_before_relax(fragP, segment);
646 #ifndef WORKING_DOT_WORD
647 /* Broken words don't concern us yet */
653 BAD_CASE(fragP->fr_type);
655 } /* switch(fr_type) */
656 } /* for each frag in the segment */
662 register long stretch; /* May be any size, 0 or negative. */
663 /* Cumulative number of addresses we have */
664 /* relaxed this pass. */
665 /* We may have relaxed more than one address. */
666 register long stretched; /* Have we stretched on this pass? */
667 /* This is 'cuz stretch may be zero, when,
668 in fact some piece of code grew, and
669 another shrank. If a branch instruction
670 doesn't fit anymore, we could be scrod */
673 stretch = stretched = 0;
674 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) {
675 register long growth = 0;
676 register unsigned long was_address;
677 /* register long var; */
678 register long offset;
679 register symbolS *symbolP;
680 register long target;
684 was_address = fragP->fr_address;
685 address = fragP->fr_address += stretch;
686 symbolP = fragP->fr_symbol;
687 offset = fragP->fr_offset;
688 /* var = fragP->fr_var; */
690 switch (fragP->fr_type) {
691 case rs_fill: /* .fill never relaxes. */
695 #ifndef WORKING_DOT_WORD
696 /* JF: This is RMS's idea. I do *NOT* want to be blamed
697 for it I do not want to write it. I do not want to have
698 anything to do with it. This is not the proper way to
699 implement this misfeature. */
700 case rs_broken_word: {
701 struct broken_word *lie;
702 struct broken_word *untruth;
703 extern int md_short_jump_size;
704 extern int md_long_jump_size;
706 /* Yes this is ugly (storing the broken_word pointer
707 in the symbol slot). Still, this whole chunk of
708 code is ugly, and I don't feel like doing anything
709 about it. Think of it as stubbornness in action */
711 for (lie=(struct broken_word *)(fragP->fr_symbol);
712 lie && lie->dispfrag==fragP;
713 lie=lie->next_broken_word) {
718 offset= lie->add->sy_frag->fr_address+ S_GET_VALUE(lie->add) + lie->addnum -
719 (lie->sub->sy_frag->fr_address+ S_GET_VALUE(lie->sub));
720 if (offset<=-32768 || offset>=32767) {
722 as_warn(".word %s-%s+%ld didn't fit",
723 S_GET_NAME(lie->add),
724 S_GET_NAME(lie->sub),
727 if (fragP->fr_subtype==0) {
729 growth+=md_short_jump_size;
731 for (untruth=lie->next_broken_word;untruth && untruth->dispfrag==lie->dispfrag;untruth=untruth->next_broken_word)
732 if ((untruth->add->sy_frag == lie->add->sy_frag)
733 && S_GET_VALUE(untruth->add) == S_GET_VALUE(lie->add)) {
735 untruth->use_jump=lie;
737 growth+=md_long_jump_size;
742 } /* case rs_broken_word */
745 growth = relax_align((relax_addressT) (address + fragP->fr_fix), offset)
746 - relax_align((relax_addressT) (was_address + fragP->fr_fix), offset);
755 know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT(symbolP) == SEG_DATA) || (S_GET_SEGMENT(symbolP) == SEG_TEXT));
756 know(symbolP->sy_frag);
757 know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (symbolP->sy_frag == &zero_address_frag));
759 target += S_GET_VALUE(symbolP)
760 + symbolP->sy_frag->fr_address;
761 } /* if we have a symbol */
763 know(fragP->fr_next);
764 after = fragP->fr_next->fr_address;
765 growth = ((target - after ) > 0) ? (target - after) : 0;
766 /* Growth may be -ve, but variable part */
767 /* of frag cannot have < 0 chars. */
768 /* That is, we can't .org backwards. */
770 growth -= stretch; /* This is an absolute growth factor */
773 case rs_machine_dependent: {
774 register const relax_typeS * this_type;
775 register const relax_typeS * start_type;
776 register relax_substateT next_state;
777 register relax_substateT this_state;
779 start_type = this_type = md_relax_table + (this_state = fragP->fr_subtype);
783 #ifndef MANY_SEGMENTS
784 know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT(symbolP) == SEG_DATA) || (S_GET_SEGMENT(symbolP) == SEG_TEXT));
786 know(symbolP->sy_frag);
787 know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || symbolP->sy_frag==&zero_address_frag );
790 + symbolP->sy_frag->fr_address;
792 /* If frag has yet to be reached on this pass,
793 assume it will move by STRETCH just as we did.
794 If this is not so, it will be because some frag
795 between grows, and that will force another pass. */
797 /* JF was just address */
798 /* JF also added is_dnrange hack */
799 /* There's gotta be a better/faster/etc way
801 /* gnu@cygnus.com: I changed this from > to >=
802 because I ran into a zero-length frag (fr_fix=0)
803 which was created when the obstack needed a new
804 chunk JUST AFTER the opcode of a branch. Since
805 fr_fix is zero, fr_address of this frag is the same
806 as fr_address of the next frag. This
807 zero-length frag was variable and jumped to .+2
808 (in the next frag), but since the > comparison
809 below failed (the two were =, not >), "stretch"
810 was not added to the target. Stretch was 178, so
811 the offset appeared to be .-176 instead, which did
812 not fit into a byte branch, so the assembler
813 relaxed the branch to a word. This didn't compare
814 with what happened when the same source file was
815 assembled on other machines, which is how I found it.
816 You might want to think about what other places have
817 trouble with zero length frags... */
819 if (symbolP->sy_frag->fr_address >= was_address
820 && is_dnrange(fragP,symbolP->sy_frag)) {
824 } /* if there's a symbol attached */
826 aim = target - address - fragP->fr_fix;
827 /* The displacement is affected by the instruction size
828 * for the 32k architecture. I think we ought to be able
829 * to add fragP->fr_pcrel_adjust in all cases (it should be
830 * zero if not used), but just in case it breaks something
831 * else we'll put this inside #ifdef NS32K ... #endif
834 aim += fragP->fr_pcrel_adjust;
835 #endif /* TC_NS32K */
838 /* Look backwards. */
839 for (next_state = this_type->rlx_more; next_state; ) {
840 if (aim >= this_type->rlx_backward) {
842 } else { /* Grow to next state. */
843 this_type = md_relax_table + (this_state = next_state);
844 next_state = this_type->rlx_more;
849 /* JF these next few lines of code are for the mc68020 which can't handle short
850 offsets of zero in branch instructions. What a kludge! */
851 if (aim==0 && this_state==(1<<2+0)) { /* FOO hard encoded from m.c */
852 aim=this_type->rlx_forward+1; /* Force relaxation into word mode */
855 #ifdef M68K_AIM_KLUDGE
856 M68K_AIM_KLUDGE(aim, this_state, this_type);
858 /* JF end of 68020 code */
860 for (next_state = this_type->rlx_more; next_state; ) {
861 if (aim <= this_type->rlx_forward) {
863 } else { /* Grow to next state. */
864 this_type = md_relax_table + (this_state = next_state);
865 next_state = this_type->rlx_more;
870 if ((growth = this_type->rlx_length - start_type->rlx_length) != 0)
871 fragP->fr_subtype = this_state;
874 } /* case rs_machine_dependent */
877 BAD_CASE( fragP->fr_type );
884 } /* For each frag in the segment. */
885 } while (stretched); /* Until nothing further to relax. */
889 * We now have valid fr_address'es for each frag.
893 * All fr_address's are correct, relative to their own segment.
894 * We have made all the fixS we will ever make.
896 } /* relax_segment() */
899 * Relax_align. Advance location counter to next address that has 'alignment'
900 * lowest order bits all 0s.
903 /* How many addresses does the .align take? */
904 static relax_addressT relax_align(address, alignment)
905 register relax_addressT address; /* Address now. */
906 register long alignment; /* Alignment (binary). */
909 relax_addressT new_address;
911 mask = ~ ( (~0) << alignment );
912 new_address = (address + mask) & (~ mask);
913 return (new_address - address);
914 } /* relax_align() */
918 Go through all the fixS's in a segment and see which ones can be
919 handled now. (These consist of fixS where we have since discovered
920 the value of a symbol, or the address of the frag involved.)
921 For each one, call md_apply_fix to put the fix into the frag data.
923 Result is a count of how many relocation structs will be needed to
924 handle the remaining fixS's that we couldn't completely handle here.
925 These will be output later by emit_relocations(). */
927 static long fixup_segment(fixP, this_segment_type)
928 register fixS * fixP;
929 segT this_segment_type; /* N_TYPE bits for segment. */
931 register long seg_reloc_count;
932 register symbolS *add_symbolP;
933 register symbolS *sub_symbolP;
934 register long add_number;
936 register char *place;
939 register fragS *fragP;
940 register segT add_symbol_segment = SEG_ABSOLUTE;
942 /* FIXME: remove this line */ /* fixS *orig = fixP; */
945 for ( ; fixP; fixP = fixP->fx_next) {
946 fragP = fixP->fx_frag;
948 where = fixP->fx_where;
949 place = fragP->fr_literal + where;
950 size = fixP->fx_size;
951 add_symbolP = fixP->fx_addsy;
953 if (fixP->fx_callj && TC_S_IS_CALLNAME(add_symbolP)) {
954 /* Relocation should be done via the
955 associated 'bal' entry point
958 if (!TC_S_IS_BALNAME(tc_get_bal_of_call(add_symbolP))) {
959 as_bad("No 'bal' entry point for leafproc %s",
960 S_GET_NAME(add_symbolP));
963 fixP->fx_addsy = add_symbolP = tc_get_bal_of_call(add_symbolP);
964 } /* callj relocation */
966 sub_symbolP = fixP->fx_subsy;
967 add_number = fixP->fx_offset;
968 pcrel = fixP->fx_pcrel;
971 add_symbol_segment = S_GET_SEGMENT(add_symbolP);
972 } /* if there is an addend */
977 if (S_GET_SEGMENT(sub_symbolP) != SEG_ABSOLUTE) {
978 as_bad("Negative of non-absolute symbol %s", S_GET_NAME(sub_symbolP));
981 add_number -= S_GET_VALUE(sub_symbolP);
983 /* if sub_symbol is in the same segment that add_symbol
984 and add_symbol is either in DATA, TEXT, BSS or ABSOLUTE */
985 } else if ((S_GET_SEGMENT(sub_symbolP) == add_symbol_segment)
986 && (SEG_NORMAL(add_symbol_segment)
987 || (add_symbol_segment == SEG_ABSOLUTE))) {
988 /* Difference of 2 symbols from same segment. */
989 /* Can't make difference of 2 undefineds: 'value' means */
990 /* something different for N_UNDF. */
992 /* Makes no sense to use the difference of 2 arbitrary symbols
993 * as the target of a call instruction.
995 if (fixP->fx_callj) {
996 as_bad("callj to difference of 2 symbols");
999 add_number += S_GET_VALUE(add_symbolP) -
1000 S_GET_VALUE(sub_symbolP);
1003 fixP->fx_addsy = NULL;
1005 /* Different segments in subtraction. */
1006 know(!(S_IS_EXTERNAL(sub_symbolP) && (S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE)));
1008 if ((S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE)) {
1009 add_number -= S_GET_VALUE(sub_symbolP);
1011 as_bad("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %d.",
1012 segment_name(S_GET_SEGMENT(sub_symbolP)),
1013 S_GET_NAME(sub_symbolP), fragP->fr_address + where);
1016 } /* if sub_symbolP */
1019 if (add_symbol_segment == this_segment_type && pcrel) {
1021 * This fixup was made when the symbol's segment was
1022 * SEG_UNKNOWN, but it is now in the local segment.
1023 * So we know how to do the address without relocation.
1026 /* reloc_callj() may replace a 'call' with a 'calls' or a 'bal',
1027 * in which cases it modifies *fixP as appropriate. In the case
1028 * of a 'calls', no further work is required, and *fixP has been
1029 * set up to make the rest of the code below a no-op.
1032 #endif /* TC_I960 */
1034 add_number += S_GET_VALUE(add_symbolP);
1035 add_number -= md_pcrel_from (fixP);
1036 pcrel = 0; /* Lie. Don't want further pcrel processing. */
1037 fixP->fx_addsy = NULL; /* No relocations please. */
1039 switch (add_symbol_segment) {
1042 reloc_callj(fixP); /* See comment about reloc_callj() above*/
1043 #endif /* TC_I960 */
1044 add_number += S_GET_VALUE(add_symbolP);
1045 fixP->fx_addsy = NULL;
1050 add_number += S_GET_VALUE(add_symbolP);
1055 if ((int)fixP->fx_bit_fixP == 13) {
1056 /* This is a COBR instruction. They have only a
1057 * 13-bit displacement and are only to be used
1058 * for local branches: flag as error, don't generate
1061 as_bad("can't use COBR format with external label");
1062 fixP->fx_addsy = NULL; /* No relocations please. */
1065 #endif /* TC_I960 */
1069 if (S_IS_COMMON(add_symbolP))
1070 add_number += S_GET_VALUE(add_symbolP);
1071 #endif /* TE_I386AIX */
1072 #endif /* OBJ_COFF */
1078 } /* switch on symbol seg */
1079 } /* if not in local seg */
1080 } /* if there was a + symbol */
1083 add_number -= md_pcrel_from(fixP);
1084 if (add_symbolP == 0) {
1085 fixP->fx_addsy = & abs_symbol;
1087 } /* if there's an add_symbol */
1090 if (!fixP->fx_bit_fixP) {
1092 (add_number& ~0xFF) && (add_number&~0xFF!=(-1&~0xFF))) ||
1094 (add_number& ~0xFFFF) && (add_number&~0xFFFF!=(-1&~0xFFFF)))) {
1095 as_bad("Value of %d too large for field of %d bytes at 0x%x",
1096 add_number, size, fragP->fr_address + where);
1097 } /* generic error checking */
1098 } /* not a bit fix */
1100 md_apply_fix(fixP, add_number);
1101 } /* For each fixS in this segment. */
1108 /* two relocs per callj under coff. */
1109 for (fixP = topP; fixP; fixP = fixP->fx_next) {
1110 if (fixP->fx_callj && fixP->fx_addsy != 0) {
1112 } /* if callj and not already fixed. */
1113 } /* for each fix */
1115 #endif /* TC_I960 */
1117 #endif /* OBJ_COFF */
1118 return(seg_reloc_count);
1119 } /* fixup_segment() */
1122 static int is_dnrange(f1,f2)
1127 if (f1->fr_next==f2)
1132 } /* is_dnrange() */
1134 /* Append a string onto another string, bumping the pointer along. */
1136 append (charPP, fromP, length)
1139 unsigned long length;
1141 if (length) { /* Don't trust memcpy() of 0 chars. */
1142 memcpy(*charPP, fromP, (int) length);
1147 int section_alignment[SEG_MAXIMUM_ORDINAL];
1150 * This routine records the largest alignment seen for each segment.
1151 * If the beginning of the segment is aligned on the worst-case
1152 * boundary, all of the other alignments within it will work. At
1153 * least one object format really uses this info.
1155 void record_alignment(seg, align)
1156 segT seg; /* Segment to which alignment pertains */
1157 int align; /* Alignment, as a power of 2
1158 * (e.g., 1 => 2-byte boundary, 2 => 4-byte boundary, etc.)
1162 if ( align > section_alignment[(int) seg] ){
1163 section_alignment[(int) seg] = align;
1164 } /* if highest yet */
1167 } /* record_alignment() */
1176 /* end of write.c */