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, r_type)
79 fragS *frag; /* Which frag? */
80 int where; /* Where in that frag? */
81 short int size; /* 1, 2, or 4 usually. */
82 symbolS *add_symbol; /* X_add_symbol. */
83 symbolS *sub_symbol; /* X_subtract_symbol. */
84 long offset; /* X_add_number. */
85 int pcrel; /* TRUE if PC-relative relocation. */
86 #if defined(TC_SPARC) || defined(TC_A29K)
87 int r_type; /* Relocation type */
92 fixP = (fixS *) obstack_alloc(¬es, sizeof(fixS));
95 fixP->fx_where = where;
97 fixP->fx_addsy = add_symbol;
98 fixP->fx_subsy = sub_symbol;
99 fixP->fx_offset = offset;
100 fixP->fx_pcrel = pcrel;
101 #if defined(TC_SPARC) || defined(TC_A29K)
102 fixP->fx_r_type = r_type;
104 /* JF these 'cuz of the NS32K stuff */
105 fixP->fx_im_disp = 0;
106 fixP->fx_pcrel_adjust = 0;
108 fixP->fx_bit_fixP = 0;
110 /* usually, we want relocs sorted numerically, but while
111 comparing to older versions of gas that have relocs
112 reverse sorted, it is convenient to have this compile
113 time option. xoxorich. */
115 #ifdef REVERSE_SORT_RELOCS
117 fixP->fx_next = *seg_fix_rootP;
118 *seg_fix_rootP = fixP;
120 #else /* REVERSE_SORT_RELOCS */
122 fixP->fx_next = NULL;
125 (*seg_fix_tailP)->fx_next = fixP;
127 *seg_fix_rootP = fixP;
128 *seg_fix_tailP = fixP;
130 #endif /* REVERSE_SORT_RELOCS */
137 void write_object_file()
139 register struct frchain * frchainP; /* Track along all frchains. */
140 register fragS * fragP; /* Track along all frags. */
141 register struct frchain * next_frchainP;
142 register fragS * * prev_fragPP;
143 /* register char * name; */
144 /* symbolS *symbolP; */
145 /* register symbolS ** symbolPP; */
146 /* register fixS * fixP; JF unused */
147 unsigned int data_siz;
149 long object_file_size;
153 * Under VMS we try to be compatible with VAX-11 "C". Thus, we
154 * call a routine to check for the definition of the procedure
155 * "_main", and if so -- fix it up so that it can be program
158 VMS_Check_For_Main();
161 * After every sub-segment, we fake an ".align ...". This conforms to BSD4.2
162 * brane-damage. We then fake ".fill 0" because that is the kind of frag
163 * that requires least thought. ".align" frags like to have a following
164 * frag since that makes calculating their intended length trivial.
166 #define SUB_SEGMENT_ALIGN (2)
167 for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next) {
170 * Under VAX/VMS, the linker (and PSECT specifications)
171 * take care of correctly aligning the segments.
172 * Doing the alignment here (on initialized data) can
173 * mess up the calculation of global data PSECT sizes.
175 #undef SUB_SEGMENT_ALIGN
176 #define SUB_SEGMENT_ALIGN ((frchainP->frch_seg != SEG_DATA) ? 2 : 0)
178 subseg_new (frchainP->frch_seg, frchainP->frch_subseg);
179 frag_align (SUB_SEGMENT_ALIGN, NOP_OPCODE);
180 /* frag_align will have left a new frag. */
181 /* Use this last frag for an empty ".fill". */
183 * For this segment ...
184 * Create a last frag. Do not leave a "being filled in frag".
186 frag_wane (frag_now);
187 frag_now->fr_fix = 0;
188 know( frag_now->fr_next == NULL );
189 /* know( frags . obstack_c_base == frags . obstack_c_next_free ); */
190 /* Above shows we haven't left a half-completed object on obstack. */
191 } /* walk the frag chain */
194 * From now on, we don't care about sub-segments.
195 * Build one frag chain for each segment. Linked thru fr_next.
196 * We know that there is at least 1 text frchain & at least 1 data frchain.
198 prev_fragPP = &text_frag_root;
199 for (frchainP = frchain_root; frchainP; frchainP = next_frchainP) {
200 know( frchainP->frch_root );
201 * prev_fragPP = frchainP->frch_root;
202 prev_fragPP = & frchainP->frch_last->fr_next;
204 if (((next_frchainP = frchainP->frch_next) == NULL)
205 || next_frchainP == data0_frchainP) {
206 prev_fragPP = & data_frag_root;
208 text_last_frag = frchainP->frch_last;
210 data_last_frag = frchainP->frch_last;
213 } /* walk the frag chain */
216 * We have two segments. If user gave -R flag, then we must put the
217 * data frags into the text segment. Do this before relaxing so
218 * we know to take advantage of -R and make shorter addresses.
220 if (flagseen[ 'R' ]) {
223 text_last_frag->fr_next = data_frag_root;
224 text_last_frag = data_last_frag;
225 data_last_frag = NULL;
226 data_frag_root = NULL;
228 for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next) ;;
229 tmp->fx_next=data_fix_root;
231 text_fix_root=data_fix_root;
235 relax_segment(text_frag_root, SEG_TEXT);
236 relax_segment(data_frag_root, SEG_DATA);
238 * Now the addresses of frags are correct within the segment.
241 know(text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0);
242 H_SET_TEXT_SIZE(&headers, text_last_frag->fr_address);
243 text_last_frag->fr_address = H_GET_TEXT_SIZE(&headers);
246 * Join the 2 segments into 1 huge segment.
247 * To do this, re-compute every rn_address in the SEG_DATA frags.
248 * Then join the data frags after the text frags.
250 * Determine a_data [length of data segment].
252 if (data_frag_root) {
253 register relax_addressT slide;
255 know((text_last_frag->fr_type == rs_fill) && (text_last_frag->fr_offset == 0));
257 H_SET_DATA_SIZE(&headers, data_last_frag->fr_address);
258 data_last_frag->fr_address = H_GET_DATA_SIZE(&headers);
259 slide = H_GET_TEXT_SIZE(&headers); /* & in file of the data segment. */
261 for (fragP = data_frag_root; fragP; fragP = fragP->fr_next) {
262 fragP->fr_address += slide;
263 } /* for each data frag */
265 know(text_last_frag != 0);
266 text_last_frag->fr_next = data_frag_root;
268 H_SET_DATA_SIZE(&headers,0);
272 bss_address_frag.fr_address = (H_GET_TEXT_SIZE(&headers) +
273 H_GET_DATA_SIZE(&headers));
275 H_SET_BSS_SIZE(&headers,local_bss_counter);
279 * Crawl the symbol chain.
281 * For each symbol whose value depends on a frag, take the address of
282 * that frag and subsume it into the value of the symbol.
283 * After this, there is just one way to lookup a symbol value.
284 * Values are left in their final state for object file emission.
285 * We adjust the values of 'L' local symbols, even if we do
286 * not intend to emit them to the object file, because their values
287 * are needed for fix-ups.
289 * Unless we saw a -L flag, remove all symbols that begin with 'L'
290 * from the symbol chain. (They are still pointed to by the fixes.)
292 * Count the remaining symbols.
293 * Assign a symbol number to each symbol.
294 * Count the number of string-table chars we will emit.
295 * Put this info into the headers as appropriate.
298 know(zero_address_frag.fr_address == 0);
299 string_byte_count = sizeof(string_byte_count);
301 obj_crawl_symbol_chain(&headers);
303 if (string_byte_count == sizeof(string_byte_count)) {
304 string_byte_count = 0;
305 } /* if no strings, then no count. */
307 H_SET_STRING_SIZE(&headers, string_byte_count);
310 * Addresses of frags now reflect addresses we use in the object file.
311 * Symbol values are correct.
312 * Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
313 * Also converting any machine-dependent frags using md_convert_frag();
315 subseg_change(SEG_TEXT, 0);
317 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) {
318 switch (fragP->fr_type) {
321 fragP->fr_type = rs_fill;
322 know(fragP->fr_var == 1);
323 know(fragP->fr_next != NULL);
325 fragP->fr_offset = (fragP->fr_next->fr_address
333 case rs_machine_dependent:
334 md_convert_frag(&headers, fragP);
336 know((fragP->fr_next == NULL) || ((fragP->fr_next->fr_address - fragP->fr_address) == fragP->fr_fix));
339 * After md_convert_frag, we make the frag into a ".space 0".
340 * Md_convert_frag() should set up any fixSs and constants
346 #ifndef WORKING_DOT_WORD
347 case rs_broken_word: {
348 struct broken_word *lie;
349 extern md_short_jump_size;
350 extern md_long_jump_size;
352 if (fragP->fr_subtype) {
353 fragP->fr_fix+=md_short_jump_size;
354 for (lie=(struct broken_word *)(fragP->fr_symbol);lie && lie->dispfrag==fragP;lie=lie->next_broken_word)
356 fragP->fr_fix+=md_long_jump_size;
364 BAD_CASE( fragP->fr_type );
366 } /* switch (fr_type) */
368 know((fragP->fr_next == NULL) || ((fragP->fr_next->fr_address - fragP->fr_address) == (fragP->fr_fix + (fragP->fr_offset * fragP->fr_var))));
369 } /* for each frag. */
371 #ifndef WORKING_DOT_WORD
373 struct broken_word *lie;
374 struct broken_word **prevP;
376 prevP= &broken_words;
377 for (lie=broken_words; lie; lie=lie->next_broken_word)
380 fix_new_ns32k(lie->frag,
381 lie->word_goes_here - lie->frag->fr_literal,
387 #elif defined(TC_SPARC) || defined(TC_A29K)
388 fix_new( lie->frag, lie->word_goes_here - lie->frag->fr_literal,
390 lie->sub, lie->addnum,
393 fix_new( lie->frag, lie->word_goes_here - lie->frag->fr_literal,
395 lie->sub, lie->addnum,
398 #endif /* TC_NS32K */
399 /* md_number_to_chars(lie->word_goes_here,
400 S_GET_VALUE(lie->add)
402 - S_GET_VALUE(lie->sub),
404 *prevP=lie->next_broken_word;
406 prevP= &(lie->next_broken_word);
408 for (lie=broken_words;lie;) {
409 struct broken_word *untruth;
417 extern md_short_jump_size;
418 extern md_long_jump_size;
422 /* Find out how many broken_words go here */
424 for (untruth=lie;untruth && untruth->dispfrag==fragP;untruth=untruth->next_broken_word)
425 if (untruth->added==1)
428 table_ptr=lie->dispfrag->fr_opcode;
429 table_addr=lie->dispfrag->fr_address+(table_ptr - lie->dispfrag->fr_literal);
430 /* Create the jump around the long jumps */
431 /* This is a short jump from table_ptr+0 to table_ptr+n*long_jump_size */
432 from_addr=table_addr;
433 to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
434 md_create_short_jump(table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
435 table_ptr+=md_short_jump_size;
436 table_addr+=md_short_jump_size;
438 for (m=0;lie && lie->dispfrag==fragP;m++,lie=lie->next_broken_word) {
441 /* Patch the jump table */
442 /* This is the offset from ??? to table_ptr+0 */
444 - S_GET_VALUE(lie->sub);
445 md_number_to_chars(lie->word_goes_here,to_addr,2);
446 for (untruth=lie->next_broken_word;untruth && untruth->dispfrag==fragP;untruth=untruth->next_broken_word) {
447 if (untruth->use_jump==lie)
448 md_number_to_chars(untruth->word_goes_here,to_addr,2);
451 /* Install the long jump */
452 /* this is a long jump from table_ptr+0 to the final target */
453 from_addr=table_addr;
454 to_addr=S_GET_VALUE(lie->add) + lie->addnum;
455 md_create_long_jump(table_ptr,from_addr,to_addr,lie->dispfrag,lie->add);
456 table_ptr+=md_long_jump_size;
457 table_addr+=md_long_jump_size;
461 #endif /* not WORKING_DOT_WORD */
466 * Scan every FixS performing fixups. We had to wait until now to do
467 * this because md_convert_frag() may have made some fixSs.
470 H_SET_RELOCATION_SIZE(&headers,
471 md_reloc_size * fixup_segment(text_fix_root, SEG_TEXT),
472 md_reloc_size * fixup_segment(data_fix_root, SEG_DATA));
475 /* FIXME move this stuff into the pre-write-hook */
476 H_SET_MAGIC_NUMBER(&headers, magic_number_for_object_file);
477 H_SET_ENTRY_POINT(&headers, 0);
479 obj_pre_write_hook(&headers); /* extra coff stuff */
480 if ((had_warnings() && flagseen['Z'])
481 || had_errors() > 0) {
483 as_warn("%d error%s, %d warning%s, generating bad object file.\n",
484 had_errors(), had_errors() == 1 ? "" : "s",
485 had_warnings(), had_warnings() == 1 ? "" : "s");
487 as_fatal("%d error%s, %d warning%s, no object file generated.\n",
488 had_errors(), had_errors() == 1 ? "" : "s",
489 had_warnings(), had_warnings() == 1 ? "" : "s");
490 } /* on want output */
491 } /* on error condition */
493 object_file_size = H_GET_FILE_SIZE(&headers);
494 next_object_file_charP = the_object_file = xmalloc(object_file_size);
496 output_file_create(out_file_name);
498 obj_header_append(&next_object_file_charP, &headers);
500 know((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE(&headers));
505 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) {
507 register char *fill_literal;
508 register long fill_size;
510 know(fragP->fr_type == rs_fill);
511 append(&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix);
512 fill_literal = fragP->fr_literal + fragP->fr_fix;
513 fill_size = fragP->fr_var;
514 know(fragP->fr_offset >= 0);
516 for (count = fragP->fr_offset; count; count--) {
517 append(&next_object_file_charP, fill_literal, (unsigned long) fill_size);
520 } /* for each code frag. */
522 know((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE(&headers) + H_GET_TEXT_SIZE(&headers) + H_GET_DATA_SIZE(&headers)));
527 obj_emit_relocations(&next_object_file_charP, text_fix_root, (relax_addressT)0);
528 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)));
530 /* Make addresses in data relocation directives relative to beginning of
531 * first data fragment, not end of last text fragment: alignment of the
532 * start of the data segment may place a gap between the segments.
534 obj_emit_relocations(&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address);
536 obj_emit_relocations(&next_object_file_charP, data_fix_root, text_last_frag->fr_address);
539 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)));
542 * Emit line number entries.
544 OBJ_EMIT_LINENO(&next_object_file_charP, lineno_rootP, the_object_file);
545 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)));
550 obj_emit_symbols(&next_object_file_charP, symbol_rootP);
551 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)));
557 if (string_byte_count > 0) {
558 obj_emit_strings(&next_object_file_charP);
559 } /* only if we have a string table */
561 /* 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)));
563 /* know(next_object_file_charP == the_object_file + object_file_size);*/
566 bfd_seek(stdoutput, 0, 0);
567 bfd_write(the_object_file, 1, object_file_size, stdoutput);
570 /* Write the data to the file */
571 output_file_append(the_object_file,object_file_size,out_file_name);
574 output_file_close(out_file_name);
575 } /* non vms output */
578 * Now do the VMS-dependent part of writing the object file
580 VMS_write_object_file(text_siz, data_siz, text_frag_root, data_frag_root);
582 } /* write_object_file() */
589 * Now we have a segment, not a crowd of sub-segments, we can make fr_address
594 * After this, all frags in this segment have addresses that are correct
595 * within the segment. Since segments live in different file addresses,
596 * these frag addresses may not be the same as final object-file addresses.
601 void relax_segment(segment_frag_root, segment)
602 struct frag * segment_frag_root;
603 segT segment; /* SEG_DATA or SEG_TEXT */
605 register struct frag * fragP;
606 register relax_addressT address;
607 /* register relax_addressT old_address; JF unused */
608 /* register relax_addressT new_address; JF unused */
609 #ifndef MANY_SEGMENTS
610 know(segment == SEG_DATA || segment == SEG_TEXT);
612 /* In case md_estimate_size_before_relax() wants to make fixSs. */
613 subseg_change(segment, 0);
616 * For each frag in segment: count and store (a 1st guess of) fr_address.
619 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) {
620 fragP->fr_address = address;
621 address += fragP->fr_fix;
623 switch (fragP->fr_type) {
625 address += fragP->fr_offset * fragP->fr_var ;
629 address += relax_align(address, fragP->fr_offset);
634 * Assume .org is nugatory. It will grow with 1st relax.
638 case rs_machine_dependent:
639 address += md_estimate_size_before_relax(fragP, segment);
642 #ifndef WORKING_DOT_WORD
643 /* Broken words don't concern us yet */
649 BAD_CASE(fragP->fr_type);
651 } /* switch(fr_type) */
652 } /* for each frag in the segment */
658 register long stretch; /* May be any size, 0 or negative. */
659 /* Cumulative number of addresses we have */
660 /* relaxed this pass. */
661 /* We may have relaxed more than one address. */
662 register long stretched; /* Have we stretched on this pass? */
663 /* This is 'cuz stretch may be zero, when,
664 in fact some piece of code grew, and
665 another shrank. If a branch instruction
666 doesn't fit anymore, we could be scrod */
669 stretch = stretched = 0;
670 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) {
671 register long growth = 0;
672 register unsigned long was_address;
673 /* register long var; */
674 register long offset;
675 register symbolS *symbolP;
676 register long target;
680 was_address = fragP->fr_address;
681 address = fragP->fr_address += stretch;
682 symbolP = fragP->fr_symbol;
683 offset = fragP->fr_offset;
684 /* var = fragP->fr_var; */
686 switch (fragP->fr_type) {
687 case rs_fill: /* .fill never relaxes. */
691 #ifndef WORKING_DOT_WORD
692 /* JF: This is RMS's idea. I do *NOT* want to be blamed
693 for it I do not want to write it. I do not want to have
694 anything to do with it. This is not the proper way to
695 implement this misfeature. */
696 case rs_broken_word: {
697 struct broken_word *lie;
698 struct broken_word *untruth;
699 extern int md_short_jump_size;
700 extern int md_long_jump_size;
702 /* Yes this is ugly (storing the broken_word pointer
703 in the symbol slot). Still, this whole chunk of
704 code is ugly, and I don't feel like doing anything
705 about it. Think of it as stubbornness in action */
707 for (lie=(struct broken_word *)(fragP->fr_symbol);
708 lie && lie->dispfrag==fragP;
709 lie=lie->next_broken_word) {
714 offset= lie->add->sy_frag->fr_address+ S_GET_VALUE(lie->add) + lie->addnum -
715 (lie->sub->sy_frag->fr_address+ S_GET_VALUE(lie->sub));
716 if (offset<=-32768 || offset>=32767) {
718 as_warn(".word %s-%s+%ld didn't fit",
719 S_GET_NAME(lie->add),
720 S_GET_NAME(lie->sub),
723 if (fragP->fr_subtype==0) {
725 growth+=md_short_jump_size;
727 for (untruth=lie->next_broken_word;untruth && untruth->dispfrag==lie->dispfrag;untruth=untruth->next_broken_word)
728 if ((untruth->add->sy_frag == lie->add->sy_frag)
729 && S_GET_VALUE(untruth->add) == S_GET_VALUE(lie->add)) {
731 untruth->use_jump=lie;
733 growth+=md_long_jump_size;
738 } /* case rs_broken_word */
741 growth = relax_align((relax_addressT) (address + fragP->fr_fix), offset)
742 - relax_align((relax_addressT) (was_address + fragP->fr_fix), offset);
751 know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT(symbolP) == SEG_DATA) || (S_GET_SEGMENT(symbolP) == SEG_TEXT));
752 know(symbolP->sy_frag);
753 know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (symbolP->sy_frag == &zero_address_frag));
755 target += S_GET_VALUE(symbolP)
756 + symbolP->sy_frag->fr_address;
757 } /* if we have a symbol */
759 know(fragP->fr_next);
760 after = fragP->fr_next->fr_address;
761 growth = ((target - after ) > 0) ? (target - after) : 0;
762 /* Growth may be -ve, but variable part */
763 /* of frag cannot have < 0 chars. */
764 /* That is, we can't .org backwards. */
766 growth -= stretch; /* This is an absolute growth factor */
769 case rs_machine_dependent: {
770 register const relax_typeS * this_type;
771 register const relax_typeS * start_type;
772 register relax_substateT next_state;
773 register relax_substateT this_state;
775 start_type = this_type = md_relax_table + (this_state = fragP->fr_subtype);
779 #ifndef MANY_SEGMENTS
780 know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT(symbolP) == SEG_DATA) || (S_GET_SEGMENT(symbolP) == SEG_TEXT));
782 know(symbolP->sy_frag);
783 know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || symbolP->sy_frag==&zero_address_frag );
786 + symbolP->sy_frag->fr_address;
788 /* If frag has yet to be reached on this pass,
789 assume it will move by STRETCH just as we did.
790 If this is not so, it will be because some frag
791 between grows, and that will force another pass. */
793 /* JF was just address */
794 /* JF also added is_dnrange hack */
795 /* There's gotta be a better/faster/etc way
797 /* gnu@cygnus.com: I changed this from > to >=
798 because I ran into a zero-length frag (fr_fix=0)
799 which was created when the obstack needed a new
800 chunk JUST AFTER the opcode of a branch. Since
801 fr_fix is zero, fr_address of this frag is the same
802 as fr_address of the next frag. This
803 zero-length frag was variable and jumped to .+2
804 (in the next frag), but since the > comparison
805 below failed (the two were =, not >), "stretch"
806 was not added to the target. Stretch was 178, so
807 the offset appeared to be .-176 instead, which did
808 not fit into a byte branch, so the assembler
809 relaxed the branch to a word. This didn't compare
810 with what happened when the same source file was
811 assembled on other machines, which is how I found it.
812 You might want to think about what other places have
813 trouble with zero length frags... */
815 if (symbolP->sy_frag->fr_address >= was_address
816 && is_dnrange(fragP,symbolP->sy_frag)) {
820 } /* if there's a symbol attached */
822 aim = target - address - fragP->fr_fix;
823 /* The displacement is affected by the instruction size
824 * for the 32k architecture. I think we ought to be able
825 * to add fragP->fr_pcrel_adjust in all cases (it should be
826 * zero if not used), but just in case it breaks something
827 * else we'll put this inside #ifdef NS32K ... #endif
830 aim += fragP->fr_pcrel_adjust;
831 #endif /* TC_NS32K */
834 /* Look backwards. */
835 for (next_state = this_type->rlx_more; next_state; ) {
836 if (aim >= this_type->rlx_backward) {
838 } else { /* Grow to next state. */
839 this_type = md_relax_table + (this_state = next_state);
840 next_state = this_type->rlx_more;
845 /* JF these next few lines of code are for the mc68020 which can't handle short
846 offsets of zero in branch instructions. What a kludge! */
847 if (aim==0 && this_state==(1<<2+0)) { /* FOO hard encoded from m.c */
848 aim=this_type->rlx_forward+1; /* Force relaxation into word mode */
851 #ifdef M68K_AIM_KLUDGE
852 M68K_AIM_KLUDGE(aim, this_state, this_type);
854 /* JF end of 68020 code */
856 for (next_state = this_type->rlx_more; next_state; ) {
857 if (aim <= this_type->rlx_forward) {
859 } else { /* Grow to next state. */
860 this_type = md_relax_table + (this_state = next_state);
861 next_state = this_type->rlx_more;
866 if ((growth = this_type->rlx_length - start_type->rlx_length) != 0)
867 fragP->fr_subtype = this_state;
870 } /* case rs_machine_dependent */
873 BAD_CASE( fragP->fr_type );
880 } /* For each frag in the segment. */
881 } while (stretched); /* Until nothing further to relax. */
885 * We now have valid fr_address'es for each frag.
889 * All fr_address's are correct, relative to their own segment.
890 * We have made all the fixS we will ever make.
892 } /* relax_segment() */
895 * Relax_align. Advance location counter to next address that has 'alignment'
896 * lowest order bits all 0s.
899 /* How many addresses does the .align take? */
900 static relax_addressT relax_align(address, alignment)
901 register relax_addressT address; /* Address now. */
902 register long alignment; /* Alignment (binary). */
905 relax_addressT new_address;
907 mask = ~ ( (~0) << alignment );
908 new_address = (address + mask) & (~ mask);
909 return (new_address - address);
910 } /* relax_align() */
914 Go through all the fixS's in a segment and see which ones can be
915 handled now. (These consist of fixS where we have since discovered
916 the value of a symbol, or the address of the frag involved.)
917 For each one, call md_apply_fix to put the fix into the frag data.
919 Result is a count of how many relocation structs will be needed to
920 handle the remaining fixS's that we couldn't completely handle here.
921 These will be output later by emit_relocations(). */
923 static long fixup_segment(fixP, this_segment_type)
924 register fixS * fixP;
925 segT this_segment_type; /* N_TYPE bits for segment. */
927 register long seg_reloc_count;
928 register symbolS *add_symbolP;
929 register symbolS *sub_symbolP;
930 register long add_number;
932 register char *place;
935 register fragS *fragP;
936 register segT add_symbol_segment = SEG_ABSOLUTE;
938 /* FIXME: remove this line */ /* fixS *orig = fixP; */
941 for ( ; fixP; fixP = fixP->fx_next) {
942 fragP = fixP->fx_frag;
944 where = fixP->fx_where;
945 place = fragP->fr_literal + where;
946 size = fixP->fx_size;
947 add_symbolP = fixP->fx_addsy;
949 if (fixP->fx_callj && TC_S_IS_CALLNAME(add_symbolP)) {
950 /* Relocation should be done via the
951 associated 'bal' entry point
954 if (!TC_S_IS_BALNAME(tc_get_bal_of_call(add_symbolP))) {
955 as_bad("No 'bal' entry point for leafproc %s",
956 S_GET_NAME(add_symbolP));
959 fixP->fx_addsy = add_symbolP = tc_get_bal_of_call(add_symbolP);
960 } /* callj relocation */
962 sub_symbolP = fixP->fx_subsy;
963 add_number = fixP->fx_offset;
964 pcrel = fixP->fx_pcrel;
967 add_symbol_segment = S_GET_SEGMENT(add_symbolP);
968 } /* if there is an addend */
973 if (S_GET_SEGMENT(sub_symbolP) != SEG_ABSOLUTE) {
974 as_bad("Negative of non-absolute symbol %s", S_GET_NAME(sub_symbolP));
977 add_number -= S_GET_VALUE(sub_symbolP);
979 /* if sub_symbol is in the same segment that add_symbol
980 and add_symbol is either in DATA, TEXT, BSS or ABSOLUTE */
981 } else if ((S_GET_SEGMENT(sub_symbolP) == add_symbol_segment)
982 && (SEG_NORMAL(add_symbol_segment)
983 || (add_symbol_segment == SEG_ABSOLUTE))) {
984 /* Difference of 2 symbols from same segment. */
985 /* Can't make difference of 2 undefineds: 'value' means */
986 /* something different for N_UNDF. */
988 /* Makes no sense to use the difference of 2 arbitrary symbols
989 * as the target of a call instruction.
991 if (fixP->fx_callj) {
992 as_bad("callj to difference of 2 symbols");
995 add_number += S_GET_VALUE(add_symbolP) -
996 S_GET_VALUE(sub_symbolP);
999 fixP->fx_addsy = NULL;
1001 /* Different segments in subtraction. */
1002 know(!(S_IS_EXTERNAL(sub_symbolP) && (S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE)));
1004 if ((S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE)) {
1005 add_number -= S_GET_VALUE(sub_symbolP);
1007 as_bad("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %d.",
1008 segment_name(S_GET_SEGMENT(sub_symbolP)),
1009 S_GET_NAME(sub_symbolP), fragP->fr_address + where);
1012 } /* if sub_symbolP */
1015 if (add_symbol_segment == this_segment_type && pcrel) {
1017 * This fixup was made when the symbol's segment was
1018 * SEG_UNKNOWN, but it is now in the local segment.
1019 * So we know how to do the address without relocation.
1022 /* reloc_callj() may replace a 'call' with a 'calls' or a 'bal',
1023 * in which cases it modifies *fixP as appropriate. In the case
1024 * of a 'calls', no further work is required, and *fixP has been
1025 * set up to make the rest of the code below a no-op.
1028 #endif /* TC_I960 */
1030 add_number += S_GET_VALUE(add_symbolP);
1031 add_number -= md_pcrel_from (fixP);
1032 pcrel = 0; /* Lie. Don't want further pcrel processing. */
1033 fixP->fx_addsy = NULL; /* No relocations please. */
1035 switch (add_symbol_segment) {
1038 reloc_callj(fixP); /* See comment about reloc_callj() above*/
1039 #endif /* TC_I960 */
1040 add_number += S_GET_VALUE(add_symbolP);
1041 fixP->fx_addsy = NULL;
1046 add_number += S_GET_VALUE(add_symbolP);
1051 if ((int)fixP->fx_bit_fixP == 13) {
1052 /* This is a COBR instruction. They have only a
1053 * 13-bit displacement and are only to be used
1054 * for local branches: flag as error, don't generate
1057 as_bad("can't use COBR format with external label");
1058 fixP->fx_addsy = NULL; /* No relocations please. */
1061 #endif /* TC_I960 */
1065 if (S_IS_COMMON(add_symbolP))
1066 add_number += S_GET_VALUE(add_symbolP);
1067 #endif /* TE_I386AIX */
1068 #endif /* OBJ_COFF */
1074 } /* switch on symbol seg */
1075 } /* if not in local seg */
1076 } /* if there was a + symbol */
1079 add_number -= md_pcrel_from(fixP);
1080 if (add_symbolP == 0) {
1081 fixP->fx_addsy = & abs_symbol;
1083 } /* if there's an add_symbol */
1086 if (!fixP->fx_bit_fixP) {
1088 (add_number& ~0xFF) && (add_number&~0xFF!=(-1&~0xFF))) ||
1090 (add_number& ~0xFFFF) && (add_number&~0xFFFF!=(-1&~0xFFFF)))) {
1091 as_bad("Value of %d too large for field of %d bytes at 0x%x",
1092 add_number, size, fragP->fr_address + where);
1093 } /* generic error checking */
1094 } /* not a bit fix */
1096 md_apply_fix(fixP, add_number);
1097 } /* For each fixS in this segment. */
1104 /* two relocs per callj under coff. */
1105 for (fixP = topP; fixP; fixP = fixP->fx_next) {
1106 if (fixP->fx_callj && fixP->fx_addsy != 0) {
1108 } /* if callj and not already fixed. */
1109 } /* for each fix */
1111 #endif /* TC_I960 */
1113 #endif /* OBJ_COFF */
1114 return(seg_reloc_count);
1115 } /* fixup_segment() */
1118 static int is_dnrange(f1,f2)
1123 if (f1->fr_next==f2)
1128 } /* is_dnrange() */
1130 /* Append a string onto another string, bumping the pointer along. */
1132 append (charPP, fromP, length)
1135 unsigned long length;
1137 if (length) { /* Don't trust memcpy() of 0 chars. */
1138 memcpy(*charPP, fromP, (int) length);
1143 int section_alignment[SEG_MAXIMUM_ORDINAL];
1146 * This routine records the largest alignment seen for each segment.
1147 * If the beginning of the segment is aligned on the worst-case
1148 * boundary, all of the other alignments within it will work. At
1149 * least one object format really uses this info.
1151 void record_alignment(seg, align)
1152 segT seg; /* Segment to which alignment pertains */
1153 int align; /* Alignment, as a power of 2
1154 * (e.g., 1 => 2-byte boundary, 2 => 4-byte boundary, etc.)
1158 if ( align > section_alignment[(int) seg] ){
1159 section_alignment[(int) seg] = align;
1160 } /* if highest yet */
1163 } /* record_alignment() */
1172 /* end of write.c */