1 /* BFD support for the ns32k architecture.
2 Copyright (C) 1990-2018 Free Software Foundation, Inc.
3 Almost totally rewritten by Ian Dall from initial work
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 MA 02110-1301, USA. */
28 #define N(machine, printable, d, next) \
29 { 32, 32, 8, bfd_arch_ns32k, machine, "ns32k",printable,3,d, \
30 bfd_default_compatible,bfd_default_scan,bfd_arch_default_fill,next, }
32 static const bfd_arch_info_type arch_info_struct[] =
34 N(32532,"ns32k:32532",TRUE, 0), /* The word ns32k will match this too. */
37 const bfd_arch_info_type bfd_ns32k_arch =
38 N(32032,"ns32k:32032",FALSE, &arch_info_struct[0]);
41 _bfd_ns32k_get_displacement (bfd_byte *buffer, int size)
48 value = ((*buffer & 0x7f) ^ 0x40) - 0x40;
52 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
53 value = (value << 8) | (0xff & *buffer);
57 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
58 value = (value << 8) | (0xff & *buffer++);
59 value = (value << 8) | (0xff & *buffer++);
60 value = (value << 8) | (0xff & *buffer);
72 _bfd_ns32k_put_displacement (bfd_vma value, bfd_byte *buffer, int size)
84 *buffer++ = (value >> 8);
89 value |= (bfd_vma) 0xc0000000;
90 *buffer++ = (value >> 24);
91 *buffer++ = (value >> 16);
92 *buffer++ = (value >> 8);
100 _bfd_ns32k_get_immediate (bfd_byte *buffer, int size)
107 value = (value << 8) | (*buffer++ & 0xff);
108 value = (value << 8) | (*buffer++ & 0xff);
111 value = (value << 8) | (*buffer++ & 0xff);
114 value = (value << 8) | (*buffer++ & 0xff);
123 _bfd_ns32k_put_immediate (bfd_vma value, bfd_byte *buffer, int size)
129 *buffer-- = (value & 0xff); value >>= 8;
130 *buffer-- = (value & 0xff); value >>= 8;
133 *buffer-- = (value & 0xff); value >>= 8;
136 *buffer-- = (value & 0xff); value >>= 8;
140 /* This is just like the standard perform_relocation except we
141 use get_data and put_data which know about the ns32k storage
142 methods. This is probably a lot more complicated than it
145 static bfd_reloc_status_type
146 do_ns32k_reloc (bfd * abfd,
147 arelent * reloc_entry,
148 struct bfd_symbol * symbol,
150 asection * input_section,
152 char ** error_message ATTRIBUTE_UNUSED,
153 bfd_vma (* get_data) (bfd_byte *, int),
154 void (* put_data) (bfd_vma, bfd_byte *, int))
158 bfd_reloc_status_type flag = bfd_reloc_ok;
159 bfd_size_type addr = reloc_entry->address;
160 bfd_vma output_base = 0;
161 reloc_howto_type *howto = reloc_entry->howto;
162 asection *reloc_target_output_section;
165 if (bfd_is_abs_section (symbol->section)
166 && output_bfd != (bfd *) NULL)
168 reloc_entry->address += input_section->output_offset;
172 /* If we are not producing relocatable output, return an error if
173 the symbol is not defined. An undefined weak symbol is
174 considered to have a value of zero (SVR4 ABI, p. 4-27). */
175 if (bfd_is_und_section (symbol->section)
176 && (symbol->flags & BSF_WEAK) == 0
177 && output_bfd == (bfd *) NULL)
178 flag = bfd_reloc_undefined;
180 /* Is the address of the relocation really within the section? */
181 if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
182 return bfd_reloc_outofrange;
184 /* Work out which section the relocation is targeted at and the
185 initial relocation command value. */
187 /* Get symbol value. (Common symbols are special.) */
188 if (bfd_is_com_section (symbol->section))
191 relocation = symbol->value;
193 reloc_target_output_section = symbol->section->output_section;
195 /* Convert input-section-relative symbol value to absolute. */
196 if (output_bfd != NULL && ! howto->partial_inplace)
199 output_base = reloc_target_output_section->vma;
201 relocation += output_base + symbol->section->output_offset;
203 /* Add in supplied addend. */
204 relocation += reloc_entry->addend;
206 /* Here the variable relocation holds the final address of the
207 symbol we are relocating against, plus any addend. */
209 if (howto->pc_relative)
211 /* This is a PC relative relocation. We want to set RELOCATION
212 to the distance between the address of the symbol and the
213 location. RELOCATION is already the address of the symbol.
215 We start by subtracting the address of the section containing
218 If pcrel_offset is set, we must further subtract the position
219 of the location within the section. Some targets arrange for
220 the addend to be the negative of the position of the location
221 within the section; for example, i386-aout does this. For
222 i386-aout, pcrel_offset is FALSE. Some other targets do not
223 include the position of the location; for example, ELF.
224 For those targets, pcrel_offset is TRUE.
226 If we are producing relocatable output, then we must ensure
227 that this reloc will be correctly computed when the final
228 relocation is done. If pcrel_offset is FALSE we want to wind
229 up with the negative of the location within the section,
230 which means we must adjust the existing addend by the change
231 in the location within the section. If pcrel_offset is TRUE
232 we do not want to adjust the existing addend at all.
234 FIXME: This seems logical to me, but for the case of
235 producing relocatable output it is not what the code
236 actually does. I don't want to change it, because it seems
237 far too likely that something will break. */
239 input_section->output_section->vma + input_section->output_offset;
241 if (howto->pcrel_offset)
242 relocation -= reloc_entry->address;
245 if (output_bfd != (bfd *) NULL)
247 if (! howto->partial_inplace)
249 /* This is a partial relocation, and we want to apply the relocation
250 to the reloc entry rather than the raw data. Modify the reloc
251 inplace to reflect what we now know. */
252 reloc_entry->addend = relocation;
253 reloc_entry->address += input_section->output_offset;
258 /* This is a partial relocation, but inplace, so modify the
261 If we've relocated with a symbol with a section, change
262 into a ref to the section belonging to the symbol. */
264 reloc_entry->address += input_section->output_offset;
267 if (abfd->xvec->flavour == bfd_target_coff_flavour)
269 /* For m68k-coff, the addend was being subtracted twice during
270 relocation with -r. Removing the line below this comment
271 fixes that problem; see PR 2953.
273 However, Ian wrote the following, regarding removing the line
274 below, which explains why it is still enabled: --djm
276 If you put a patch like that into BFD you need to check all
277 the COFF linkers. I am fairly certain that patch will break
278 coff-i386 (e.g., SCO); see coff_i386_reloc in coff-i386.c
279 where I worked around the problem in a different way. There
280 may very well be a reason that the code works as it does.
282 Hmmm. The first obvious point is that bfd_perform_relocation
283 should not have any tests that depend upon the flavour. It's
284 seem like entirely the wrong place for such a thing. The
285 second obvious point is that the current code ignores the
286 reloc addend when producing relocatable output for COFF.
287 That's peculiar. In fact, I really have no idea what the
288 point of the line you want to remove is.
290 A typical COFF reloc subtracts the old value of the symbol
291 and adds in the new value to the location in the object file
292 (if it's a pc relative reloc it adds the difference between
293 the symbol value and the location). When relocating we need
294 to preserve that property.
296 BFD handles this by setting the addend to the negative of the
297 old value of the symbol. Unfortunately it handles common
298 symbols in a non-standard way (it doesn't subtract the old
299 value) but that's a different story (we can't change it
300 without losing backward compatibility with old object files)
301 (coff-i386 does subtract the old value, to be compatible with
302 existing coff-i386 targets, like SCO).
304 So everything works fine when not producing relocatable
305 output. When we are producing relocatable output, logically
306 we should do exactly what we do when not producing
307 relocatable output. Therefore, your patch is correct. In
308 fact, it should probably always just set reloc_entry->addend
309 to 0 for all cases, since it is, in fact, going to add the
310 value into the object file. This won't hurt the COFF code,
311 which doesn't use the addend; I'm not sure what it will do
312 to other formats (the thing to check for would be whether
313 any formats both use the addend and set partial_inplace).
315 When I wanted to make coff-i386 produce relocatable output,
316 I ran into the problem that you are running into: I wanted
317 to remove that line. Rather than risk it, I made the
318 coff-i386 relocs use a special function; it's coff_i386_reloc
319 in coff-i386.c. The function specifically adds the addend
320 field into the object file, knowing that bfd_perform_relocation
321 is not going to. If you remove that line, then coff-i386.c
322 will wind up adding the addend field in twice. It's trivial
323 to fix; it just needs to be done.
325 The problem with removing the line is just that it may break
326 some working code. With BFD it's hard to be sure of anything.
327 The right way to deal with this is simply to build and test at
328 least all the supported COFF targets. It should be
329 straightforward if time and disk space consuming. For each
332 2) generate some executable, and link it using -r (I would
333 probably use paranoia.o and link against newlib/libc.a,
334 which for all the supported targets would be available in
335 /usr/cygnus/progressive/H-host/target/lib/libc.a).
336 3) make the change to reloc.c
337 4) rebuild the linker
339 6) if the resulting object files are the same, you have at
340 least made it no worse
341 7) if they are different you have to figure out which
343 relocation -= reloc_entry->addend;
344 reloc_entry->addend = 0;
348 reloc_entry->addend = relocation;
354 reloc_entry->addend = 0;
357 /* FIXME: This overflow checking is incomplete, because the value
358 might have overflowed before we get here. For a correct check we
359 need to compute the value in a size larger than bitsize, but we
360 can't reasonably do that for a reloc the same size as a host
362 FIXME: We should also do overflow checking on the result after
363 adding in the value contained in the object file. */
364 if (howto->complain_on_overflow != complain_overflow_dont)
368 /* Get the value that will be used for the relocation, but
369 starting at bit position zero. */
370 if (howto->rightshift > howto->bitpos)
371 check = relocation >> (howto->rightshift - howto->bitpos);
373 check = relocation << (howto->bitpos - howto->rightshift);
374 switch (howto->complain_on_overflow)
376 case complain_overflow_signed:
378 /* Assumes two's complement. */
379 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
380 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
382 /* The above right shift is incorrect for a signed value.
383 Fix it up by forcing on the upper bits. */
384 if (howto->rightshift > howto->bitpos
385 && (bfd_signed_vma) relocation < 0)
386 check |= ((bfd_vma) - 1
388 >> (howto->rightshift - howto->bitpos)));
389 if ((bfd_signed_vma) check > reloc_signed_max
390 || (bfd_signed_vma) check < reloc_signed_min)
391 flag = bfd_reloc_overflow;
394 case complain_overflow_unsigned:
396 /* Assumes two's complement. This expression avoids
397 overflow if howto->bitsize is the number of bits in
399 bfd_vma reloc_unsigned_max =
400 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
402 if ((bfd_vma) check > reloc_unsigned_max)
403 flag = bfd_reloc_overflow;
406 case complain_overflow_bitfield:
408 /* Assumes two's complement. This expression avoids
409 overflow if howto->bitsize is the number of bits in
411 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
413 if (((bfd_vma) check & ~reloc_bits) != 0
414 && (((bfd_vma) check & ~reloc_bits)
415 != (-(bfd_vma) 1 & ~reloc_bits)))
417 /* The above right shift is incorrect for a signed
418 value. See if turning on the upper bits fixes the
420 if (howto->rightshift > howto->bitpos
421 && (bfd_signed_vma) relocation < 0)
423 check |= ((bfd_vma) - 1
425 >> (howto->rightshift - howto->bitpos)));
426 if (((bfd_vma) check & ~reloc_bits)
427 != (-(bfd_vma) 1 & ~reloc_bits))
428 flag = bfd_reloc_overflow;
431 flag = bfd_reloc_overflow;
440 /* Either we are relocating all the way, or we don't want to apply
441 the relocation to the reloc entry (probably because there isn't
442 any room in the output format to describe addends to relocs). */
444 /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
445 (OSF version 1.3, compiler version 3.11). It miscompiles the
459 x <<= (unsigned long) s.i0;
463 printf ("succeeded (%lx)\n", x);
467 relocation >>= (bfd_vma) howto->rightshift;
469 /* Shift everything up to where it's going to be used. */
470 relocation <<= (bfd_vma) howto->bitpos;
472 /* Wait for the day when all have the mask in them. */
475 i instruction to be left alone
476 o offset within instruction
477 r relocation offset to apply
486 i i i i i o o o o o from bfd_get<size>
487 and S S S S S to get the size offset we want
488 + r r r r r r r r r r to get the final value to place
489 and D D D D D to chop to right size
490 -----------------------
493 ... i i i i i o o o o o from bfd_get<size>
494 and N N N N N get instruction
495 -----------------------
501 -----------------------
502 R R R R R R R R R R put into bfd_put<size>. */
505 relocation = -relocation;
508 x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
510 location = (bfd_byte *) data + addr;
515 bfd_vma x = get_data (location, 1);
517 put_data ((bfd_vma) x, location, 1);
524 bfd_vma x = get_data (location, 2);
526 put_data ((bfd_vma) x, location, 2);
532 bfd_vma x = get_data (location, 4);
534 put_data ((bfd_vma) x, location, 4);
546 bfd_vma x = get_data (location, 8);
548 put_data (x, location, 8);
555 return bfd_reloc_other;
557 if ((howto->complain_on_overflow != complain_overflow_dont) && overflow)
558 return bfd_reloc_overflow;
563 /* Relocate a given location using a given value and howto. */
565 bfd_reloc_status_type
566 _bfd_do_ns32k_reloc_contents (reloc_howto_type *howto,
567 bfd *input_bfd ATTRIBUTE_UNUSED,
570 bfd_vma (*get_data) (bfd_byte *, int),
571 void (*put_data) (bfd_vma, bfd_byte *, int))
575 bfd_boolean overflow;
577 /* If the size is negative, negate RELOCATION. This isn't very
580 relocation = -relocation;
582 /* Get the value we are going to relocate. */
583 size = bfd_get_reloc_size (howto);
596 x = get_data (location, size);
600 /* Check for overflow. FIXME: We may drop bits during the addition
601 which we don't check for. We must either check at every single
602 operation, which would be tedious, or we must do the computations
603 in a type larger than bfd_vma, which would be inefficient. */
605 if (howto->complain_on_overflow != complain_overflow_dont)
608 bfd_signed_vma signed_check;
610 bfd_signed_vma signed_add;
612 if (howto->rightshift == 0)
615 signed_check = (bfd_signed_vma) relocation;
619 /* Drop unwanted bits from the value we are relocating to. */
620 check = relocation >> howto->rightshift;
622 /* If this is a signed value, the rightshift just dropped
623 leading 1 bits (assuming twos complement). */
624 if ((bfd_signed_vma) relocation >= 0)
625 signed_check = check;
627 signed_check = (check
629 & ~((bfd_vma) - 1 >> howto->rightshift)));
632 /* Get the value from the object file. */
633 add = x & howto->src_mask;
635 /* Get the value from the object file with an appropriate sign.
636 The expression involving howto->src_mask isolates the upper
637 bit of src_mask. If that bit is set in the value we are
638 adding, it is negative, and we subtract out that number times
639 two. If src_mask includes the highest possible bit, then we
640 can not get the upper bit, but that does not matter since
641 signed_add needs no adjustment to become negative in that
644 if ((add & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0)
645 signed_add -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1;
647 /* Add the value from the object file, shifted so that it is a
649 if (howto->bitpos == 0)
652 signed_check += signed_add;
656 check += add >> howto->bitpos;
658 /* For the signed case we use ADD, rather than SIGNED_ADD,
659 to avoid warnings from SVR4 cc. This is OK since we
660 explicitly handle the sign bits. */
662 signed_check += add >> howto->bitpos;
664 signed_check += ((add >> howto->bitpos)
666 & ~((bfd_vma) - 1 >> howto->bitpos)));
669 switch (howto->complain_on_overflow)
671 case complain_overflow_signed:
673 /* Assumes two's complement. */
674 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
675 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
677 if (signed_check > reloc_signed_max
678 || signed_check < reloc_signed_min)
682 case complain_overflow_unsigned:
684 /* Assumes two's complement. This expression avoids
685 overflow if howto->bitsize is the number of bits in
687 bfd_vma reloc_unsigned_max =
688 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
690 if (check > reloc_unsigned_max)
694 case complain_overflow_bitfield:
696 /* Assumes two's complement. This expression avoids
697 overflow if howto->bitsize is the number of bits in
699 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
701 if ((check & ~reloc_bits) != 0
702 && (((bfd_vma) signed_check & ~reloc_bits)
703 != (-(bfd_vma) 1 & ~reloc_bits)))
712 /* Put RELOCATION in the right bits. */
713 relocation >>= (bfd_vma) howto->rightshift;
714 relocation <<= (bfd_vma) howto->bitpos;
716 /* Add RELOCATION to the right bits of X. */
717 x = ((x & ~howto->dst_mask)
718 | (((x & howto->src_mask) + relocation) & howto->dst_mask));
720 /* Put the relocated value back in the object file. */
732 put_data (x, location, size);
736 return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
739 bfd_reloc_status_type
740 _bfd_ns32k_reloc_disp (bfd *abfd,
741 arelent *reloc_entry,
742 struct bfd_symbol *symbol,
744 asection *input_section,
746 char **error_message)
748 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
749 output_bfd, error_message,
750 _bfd_ns32k_get_displacement,
751 _bfd_ns32k_put_displacement);
754 bfd_reloc_status_type
755 _bfd_ns32k_reloc_imm (bfd *abfd,
756 arelent *reloc_entry,
757 struct bfd_symbol *symbol,
759 asection *input_section,
761 char **error_message)
763 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
764 output_bfd, error_message, _bfd_ns32k_get_immediate,
765 _bfd_ns32k_put_immediate);
768 bfd_reloc_status_type
769 _bfd_ns32k_final_link_relocate (reloc_howto_type *howto,
771 asection *input_section,
779 /* Sanity check the address. */
780 if (address > bfd_get_section_limit (input_bfd, input_section))
781 return bfd_reloc_outofrange;
783 /* This function assumes that we are dealing with a basic relocation
784 against a symbol. We want to compute the value of the symbol to
785 relocate to. This is just VALUE, the value of the symbol, plus
786 ADDEND, any addend associated with the reloc. */
787 relocation = value + addend;
789 /* If the relocation is PC relative, we want to set RELOCATION to
790 the distance between the symbol (currently in RELOCATION) and the
791 location we are relocating. If pcrel_offset is FALSE we do not
792 need to subtract out the offset of the location within the
793 section (which is just ADDRESS). */
794 if (howto->pc_relative)
796 relocation -= (input_section->output_section->vma
797 + input_section->output_offset);
798 if (howto->pcrel_offset)
799 relocation -= address;
802 return _bfd_ns32k_relocate_contents (howto, input_bfd, relocation,