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authorRichard Henderson <rth@redhat.com>1999-05-03 07:29:11 +0000
committerRichard Henderson <rth@redhat.com>1999-05-03 07:29:11 +0000
commit252b5132c753830d5fd56823373aed85f2a0db63 (patch)
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19990502 sourceware importbinu_ss_19990502
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+/* BFD support for handling relocation entries.
+ Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 1999
+ Free Software Foundation, Inc.
+ Written by Cygnus Support.
+
+This file is part of BFD, the Binary File Descriptor library.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/*
+SECTION
+ Relocations
+
+ BFD maintains relocations in much the same way it maintains
+ symbols: they are left alone until required, then read in
+ en-mass and translated into an internal form. A common
+ routine <<bfd_perform_relocation>> acts upon the
+ canonical form to do the fixup.
+
+ Relocations are maintained on a per section basis,
+ while symbols are maintained on a per BFD basis.
+
+ All that a back end has to do to fit the BFD interface is to create
+ a <<struct reloc_cache_entry>> for each relocation
+ in a particular section, and fill in the right bits of the structures.
+
+@menu
+@* typedef arelent::
+@* howto manager::
+@end menu
+
+*/
+
+/* DO compile in the reloc_code name table from libbfd.h. */
+#define _BFD_MAKE_TABLE_bfd_reloc_code_real
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "bfdlink.h"
+#include "libbfd.h"
+/*
+DOCDD
+INODE
+ typedef arelent, howto manager, Relocations, Relocations
+
+SUBSECTION
+ typedef arelent
+
+ This is the structure of a relocation entry:
+
+CODE_FRAGMENT
+.
+.typedef enum bfd_reloc_status
+.{
+. {* No errors detected *}
+. bfd_reloc_ok,
+.
+. {* The relocation was performed, but there was an overflow. *}
+. bfd_reloc_overflow,
+.
+. {* The address to relocate was not within the section supplied. *}
+. bfd_reloc_outofrange,
+.
+. {* Used by special functions *}
+. bfd_reloc_continue,
+.
+. {* Unsupported relocation size requested. *}
+. bfd_reloc_notsupported,
+.
+. {* Unused *}
+. bfd_reloc_other,
+.
+. {* The symbol to relocate against was undefined. *}
+. bfd_reloc_undefined,
+.
+. {* The relocation was performed, but may not be ok - presently
+. generated only when linking i960 coff files with i960 b.out
+. symbols. If this type is returned, the error_message argument
+. to bfd_perform_relocation will be set. *}
+. bfd_reloc_dangerous
+. }
+. bfd_reloc_status_type;
+.
+.
+.typedef struct reloc_cache_entry
+.{
+. {* A pointer into the canonical table of pointers *}
+. struct symbol_cache_entry **sym_ptr_ptr;
+.
+. {* offset in section *}
+. bfd_size_type address;
+.
+. {* addend for relocation value *}
+. bfd_vma addend;
+.
+. {* Pointer to how to perform the required relocation *}
+. reloc_howto_type *howto;
+.
+.} arelent;
+
+*/
+
+/*
+DESCRIPTION
+
+ Here is a description of each of the fields within an <<arelent>>:
+
+ o <<sym_ptr_ptr>>
+
+ The symbol table pointer points to a pointer to the symbol
+ associated with the relocation request. It is
+ the pointer into the table returned by the back end's
+ <<get_symtab>> action. @xref{Symbols}. The symbol is referenced
+ through a pointer to a pointer so that tools like the linker
+ can fix up all the symbols of the same name by modifying only
+ one pointer. The relocation routine looks in the symbol and
+ uses the base of the section the symbol is attached to and the
+ value of the symbol as the initial relocation offset. If the
+ symbol pointer is zero, then the section provided is looked up.
+
+ o <<address>>
+
+ The <<address>> field gives the offset in bytes from the base of
+ the section data which owns the relocation record to the first
+ byte of relocatable information. The actual data relocated
+ will be relative to this point; for example, a relocation
+ type which modifies the bottom two bytes of a four byte word
+ would not touch the first byte pointed to in a big endian
+ world.
+
+ o <<addend>>
+
+ The <<addend>> is a value provided by the back end to be added (!)
+ to the relocation offset. Its interpretation is dependent upon
+ the howto. For example, on the 68k the code:
+
+
+| char foo[];
+| main()
+| {
+| return foo[0x12345678];
+| }
+
+ Could be compiled into:
+
+| linkw fp,#-4
+| moveb @@#12345678,d0
+| extbl d0
+| unlk fp
+| rts
+
+
+ This could create a reloc pointing to <<foo>>, but leave the
+ offset in the data, something like:
+
+
+|RELOCATION RECORDS FOR [.text]:
+|offset type value
+|00000006 32 _foo
+|
+|00000000 4e56 fffc ; linkw fp,#-4
+|00000004 1039 1234 5678 ; moveb @@#12345678,d0
+|0000000a 49c0 ; extbl d0
+|0000000c 4e5e ; unlk fp
+|0000000e 4e75 ; rts
+
+
+ Using coff and an 88k, some instructions don't have enough
+ space in them to represent the full address range, and
+ pointers have to be loaded in two parts. So you'd get something like:
+
+
+| or.u r13,r0,hi16(_foo+0x12345678)
+| ld.b r2,r13,lo16(_foo+0x12345678)
+| jmp r1
+
+
+ This should create two relocs, both pointing to <<_foo>>, and with
+ 0x12340000 in their addend field. The data would consist of:
+
+
+|RELOCATION RECORDS FOR [.text]:
+|offset type value
+|00000002 HVRT16 _foo+0x12340000
+|00000006 LVRT16 _foo+0x12340000
+|
+|00000000 5da05678 ; or.u r13,r0,0x5678
+|00000004 1c4d5678 ; ld.b r2,r13,0x5678
+|00000008 f400c001 ; jmp r1
+
+
+ The relocation routine digs out the value from the data, adds
+ it to the addend to get the original offset, and then adds the
+ value of <<_foo>>. Note that all 32 bits have to be kept around
+ somewhere, to cope with carry from bit 15 to bit 16.
+
+ One further example is the sparc and the a.out format. The
+ sparc has a similar problem to the 88k, in that some
+ instructions don't have room for an entire offset, but on the
+ sparc the parts are created in odd sized lumps. The designers of
+ the a.out format chose to not use the data within the section
+ for storing part of the offset; all the offset is kept within
+ the reloc. Anything in the data should be ignored.
+
+| save %sp,-112,%sp
+| sethi %hi(_foo+0x12345678),%g2
+| ldsb [%g2+%lo(_foo+0x12345678)],%i0
+| ret
+| restore
+
+ Both relocs contain a pointer to <<foo>>, and the offsets
+ contain junk.
+
+
+|RELOCATION RECORDS FOR [.text]:
+|offset type value
+|00000004 HI22 _foo+0x12345678
+|00000008 LO10 _foo+0x12345678
+|
+|00000000 9de3bf90 ; save %sp,-112,%sp
+|00000004 05000000 ; sethi %hi(_foo+0),%g2
+|00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0
+|0000000c 81c7e008 ; ret
+|00000010 81e80000 ; restore
+
+
+ o <<howto>>
+
+ The <<howto>> field can be imagined as a
+ relocation instruction. It is a pointer to a structure which
+ contains information on what to do with all of the other
+ information in the reloc record and data section. A back end
+ would normally have a relocation instruction set and turn
+ relocations into pointers to the correct structure on input -
+ but it would be possible to create each howto field on demand.
+
+*/
+
+/*
+SUBSUBSECTION
+ <<enum complain_overflow>>
+
+ Indicates what sort of overflow checking should be done when
+ performing a relocation.
+
+CODE_FRAGMENT
+.
+.enum complain_overflow
+.{
+. {* Do not complain on overflow. *}
+. complain_overflow_dont,
+.
+. {* Complain if the bitfield overflows, whether it is considered
+. as signed or unsigned. *}
+. complain_overflow_bitfield,
+.
+. {* Complain if the value overflows when considered as signed
+. number. *}
+. complain_overflow_signed,
+.
+. {* Complain if the value overflows when considered as an
+. unsigned number. *}
+. complain_overflow_unsigned
+.};
+
+*/
+
+/*
+SUBSUBSECTION
+ <<reloc_howto_type>>
+
+ The <<reloc_howto_type>> is a structure which contains all the
+ information that libbfd needs to know to tie up a back end's data.
+
+CODE_FRAGMENT
+.struct symbol_cache_entry; {* Forward declaration *}
+.
+.struct reloc_howto_struct
+.{
+. {* The type field has mainly a documentary use - the back end can
+. do what it wants with it, though normally the back end's
+. external idea of what a reloc number is stored
+. in this field. For example, a PC relative word relocation
+. in a coff environment has the type 023 - because that's
+. what the outside world calls a R_PCRWORD reloc. *}
+. unsigned int type;
+.
+. {* The value the final relocation is shifted right by. This drops
+. unwanted data from the relocation. *}
+. unsigned int rightshift;
+.
+. {* The size of the item to be relocated. This is *not* a
+. power-of-two measure. To get the number of bytes operated
+. on by a type of relocation, use bfd_get_reloc_size. *}
+. int size;
+.
+. {* The number of bits in the item to be relocated. This is used
+. when doing overflow checking. *}
+. unsigned int bitsize;
+.
+. {* Notes that the relocation is relative to the location in the
+. data section of the addend. The relocation function will
+. subtract from the relocation value the address of the location
+. being relocated. *}
+. boolean pc_relative;
+.
+. {* The bit position of the reloc value in the destination.
+. The relocated value is left shifted by this amount. *}
+. unsigned int bitpos;
+.
+. {* What type of overflow error should be checked for when
+. relocating. *}
+. enum complain_overflow complain_on_overflow;
+.
+. {* If this field is non null, then the supplied function is
+. called rather than the normal function. This allows really
+. strange relocation methods to be accomodated (e.g., i960 callj
+. instructions). *}
+. bfd_reloc_status_type (*special_function)
+. PARAMS ((bfd *abfd,
+. arelent *reloc_entry,
+. struct symbol_cache_entry *symbol,
+. PTR data,
+. asection *input_section,
+. bfd *output_bfd,
+. char **error_message));
+.
+. {* The textual name of the relocation type. *}
+. char *name;
+.
+. {* When performing a partial link, some formats must modify the
+. relocations rather than the data - this flag signals this.*}
+. boolean partial_inplace;
+.
+. {* The src_mask selects which parts of the read in data
+. are to be used in the relocation sum. E.g., if this was an 8 bit
+. bit of data which we read and relocated, this would be
+. 0x000000ff. When we have relocs which have an addend, such as
+. sun4 extended relocs, the value in the offset part of a
+. relocating field is garbage so we never use it. In this case
+. the mask would be 0x00000000. *}
+. bfd_vma src_mask;
+.
+. {* The dst_mask selects which parts of the instruction are replaced
+. into the instruction. In most cases src_mask == dst_mask,
+. except in the above special case, where dst_mask would be
+. 0x000000ff, and src_mask would be 0x00000000. *}
+. bfd_vma dst_mask;
+.
+. {* When some formats create PC relative instructions, they leave
+. the value of the pc of the place being relocated in the offset
+. slot of the instruction, so that a PC relative relocation can
+. be made just by adding in an ordinary offset (e.g., sun3 a.out).
+. Some formats leave the displacement part of an instruction
+. empty (e.g., m88k bcs); this flag signals the fact.*}
+. boolean pcrel_offset;
+.
+.};
+
+*/
+
+/*
+FUNCTION
+ The HOWTO Macro
+
+DESCRIPTION
+ The HOWTO define is horrible and will go away.
+
+
+.#define HOWTO(C, R,S,B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \
+. {(unsigned)C,R,S,B, P, BI, O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC}
+
+DESCRIPTION
+ And will be replaced with the totally magic way. But for the
+ moment, we are compatible, so do it this way.
+
+
+.#define NEWHOWTO( FUNCTION, NAME,SIZE,REL,IN) HOWTO(0,0,SIZE,0,REL,0,complain_overflow_dont,FUNCTION, NAME,false,0,0,IN)
+.
+DESCRIPTION
+ Helper routine to turn a symbol into a relocation value.
+
+.#define HOWTO_PREPARE(relocation, symbol) \
+. { \
+. if (symbol != (asymbol *)NULL) { \
+. if (bfd_is_com_section (symbol->section)) { \
+. relocation = 0; \
+. } \
+. else { \
+. relocation = symbol->value; \
+. } \
+. } \
+.}
+
+*/
+
+/*
+FUNCTION
+ bfd_get_reloc_size
+
+SYNOPSIS
+ unsigned int bfd_get_reloc_size (reloc_howto_type *);
+
+DESCRIPTION
+ For a reloc_howto_type that operates on a fixed number of bytes,
+ this returns the number of bytes operated on.
+ */
+
+unsigned int
+bfd_get_reloc_size (howto)
+ reloc_howto_type *howto;
+{
+ switch (howto->size)
+ {
+ case 0: return 1;
+ case 1: return 2;
+ case 2: return 4;
+ case 3: return 0;
+ case 4: return 8;
+ case 8: return 16;
+ case -2: return 4;
+ default: abort ();
+ }
+}
+
+/*
+TYPEDEF
+ arelent_chain
+
+DESCRIPTION
+
+ How relocs are tied together in an <<asection>>:
+
+.typedef struct relent_chain {
+. arelent relent;
+. struct relent_chain *next;
+.} arelent_chain;
+
+*/
+
+/* N_ONES produces N one bits, without overflowing machine arithmetic. */
+#define N_ONES(n) (((((bfd_vma) 1 << ((n) - 1)) - 1) << 1) | 1)
+
+/*
+FUNCTION
+ bfd_check_overflow
+
+SYNOPSIS
+ bfd_reloc_status_type
+ bfd_check_overflow
+ (enum complain_overflow how,
+ unsigned int bitsize,
+ unsigned int rightshift,
+ unsigned int addrsize,
+ bfd_vma relocation);
+
+DESCRIPTION
+ Perform overflow checking on @var{relocation} which has
+ @var{bitsize} significant bits and will be shifted right by
+ @var{rightshift} bits, on a machine with addresses containing
+ @var{addrsize} significant bits. The result is either of
+ @code{bfd_reloc_ok} or @code{bfd_reloc_overflow}.
+
+*/
+
+bfd_reloc_status_type
+bfd_check_overflow (how, bitsize, rightshift, addrsize, relocation)
+ enum complain_overflow how;
+ unsigned int bitsize;
+ unsigned int rightshift;
+ unsigned int addrsize;
+ bfd_vma relocation;
+{
+ bfd_vma fieldmask, addrmask, signmask, ss, a;
+ bfd_reloc_status_type flag = bfd_reloc_ok;
+
+ a = relocation;
+
+ /* Note: BITSIZE should always be <= ADDRSIZE, but in case it's not,
+ we'll be permissive: extra bits in the field mask will
+ automatically extend the address mask for purposes of the
+ overflow check. */
+ fieldmask = N_ONES (bitsize);
+ addrmask = N_ONES (addrsize) | fieldmask;
+
+ switch (how)
+ {
+ case complain_overflow_dont:
+ break;
+
+ case complain_overflow_signed:
+ /* If any sign bits are set, all sign bits must be set. That
+ is, A must be a valid negative address after shifting. */
+ a = (a & addrmask) >> rightshift;
+ signmask = ~ (fieldmask >> 1);
+ ss = a & signmask;
+ if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
+ flag = bfd_reloc_overflow;
+ break;
+
+ case complain_overflow_unsigned:
+ /* We have an overflow if the address does not fit in the field. */
+ a = (a & addrmask) >> rightshift;
+ if ((a & ~ fieldmask) != 0)
+ flag = bfd_reloc_overflow;
+ break;
+
+ case complain_overflow_bitfield:
+ /* Bitfields are sometimes signed, sometimes unsigned. We
+ overflow if the value has some, but not all, bits set outside
+ the field, or if it has any bits set outside the field but
+ the sign bit is not set. */
+ a >>= rightshift;
+ if ((a & ~ fieldmask) != 0)
+ {
+ signmask = (fieldmask >> 1) + 1;
+ ss = (signmask << rightshift) - 1;
+ if ((ss | relocation) != ~ (bfd_vma) 0)
+ flag = bfd_reloc_overflow;
+ }
+ break;
+
+ default:
+ abort ();
+ }
+
+ return flag;
+}
+
+/*
+FUNCTION
+ bfd_perform_relocation
+
+SYNOPSIS
+ bfd_reloc_status_type
+ bfd_perform_relocation
+ (bfd *abfd,
+ arelent *reloc_entry,
+ PTR data,
+ asection *input_section,
+ bfd *output_bfd,
+ char **error_message);
+
+DESCRIPTION
+ If @var{output_bfd} is supplied to this function, the
+ generated image will be relocatable; the relocations are
+ copied to the output file after they have been changed to
+ reflect the new state of the world. There are two ways of
+ reflecting the results of partial linkage in an output file:
+ by modifying the output data in place, and by modifying the
+ relocation record. Some native formats (e.g., basic a.out and
+ basic coff) have no way of specifying an addend in the
+ relocation type, so the addend has to go in the output data.
+ This is no big deal since in these formats the output data
+ slot will always be big enough for the addend. Complex reloc
+ types with addends were invented to solve just this problem.
+ The @var{error_message} argument is set to an error message if
+ this return @code{bfd_reloc_dangerous}.
+
+*/
+
+
+bfd_reloc_status_type
+bfd_perform_relocation (abfd, reloc_entry, data, input_section, output_bfd,
+ error_message)
+ bfd *abfd;
+ arelent *reloc_entry;
+ PTR data;
+ asection *input_section;
+ bfd *output_bfd;
+ char **error_message;
+{
+ bfd_vma relocation;
+ bfd_reloc_status_type flag = bfd_reloc_ok;
+ bfd_size_type addr = reloc_entry->address;
+ bfd_vma output_base = 0;
+ reloc_howto_type *howto = reloc_entry->howto;
+ asection *reloc_target_output_section;
+ asymbol *symbol;
+
+ symbol = *(reloc_entry->sym_ptr_ptr);
+ if (bfd_is_abs_section (symbol->section)
+ && output_bfd != (bfd *) NULL)
+ {
+ reloc_entry->address += input_section->output_offset;
+ return bfd_reloc_ok;
+ }
+
+ /* If we are not producing relocateable output, return an error if
+ the symbol is not defined. An undefined weak symbol is
+ considered to have a value of zero (SVR4 ABI, p. 4-27). */
+ if (bfd_is_und_section (symbol->section)
+ && (symbol->flags & BSF_WEAK) == 0
+ && output_bfd == (bfd *) NULL)
+ flag = bfd_reloc_undefined;
+
+ /* If there is a function supplied to handle this relocation type,
+ call it. It'll return `bfd_reloc_continue' if further processing
+ can be done. */
+ if (howto->special_function)
+ {
+ bfd_reloc_status_type cont;
+ cont = howto->special_function (abfd, reloc_entry, symbol, data,
+ input_section, output_bfd,
+ error_message);
+ if (cont != bfd_reloc_continue)
+ return cont;
+ }
+
+ /* Is the address of the relocation really within the section? */
+ if (reloc_entry->address > input_section->_cooked_size)
+ return bfd_reloc_outofrange;
+
+ /* Work out which section the relocation is targetted at and the
+ initial relocation command value. */
+
+ /* Get symbol value. (Common symbols are special.) */
+ if (bfd_is_com_section (symbol->section))
+ relocation = 0;
+ else
+ relocation = symbol->value;
+
+
+ reloc_target_output_section = symbol->section->output_section;
+
+ /* Convert input-section-relative symbol value to absolute. */
+ if (output_bfd && howto->partial_inplace == false)
+ output_base = 0;
+ else
+ output_base = reloc_target_output_section->vma;
+
+ relocation += output_base + symbol->section->output_offset;
+
+ /* Add in supplied addend. */
+ relocation += reloc_entry->addend;
+
+ /* Here the variable relocation holds the final address of the
+ symbol we are relocating against, plus any addend. */
+
+ if (howto->pc_relative == true)
+ {
+ /* This is a PC relative relocation. We want to set RELOCATION
+ to the distance between the address of the symbol and the
+ location. RELOCATION is already the address of the symbol.
+
+ We start by subtracting the address of the section containing
+ the location.
+
+ If pcrel_offset is set, we must further subtract the position
+ of the location within the section. Some targets arrange for
+ the addend to be the negative of the position of the location
+ within the section; for example, i386-aout does this. For
+ i386-aout, pcrel_offset is false. Some other targets do not
+ include the position of the location; for example, m88kbcs,
+ or ELF. For those targets, pcrel_offset is true.
+
+ If we are producing relocateable output, then we must ensure
+ that this reloc will be correctly computed when the final
+ relocation is done. If pcrel_offset is false we want to wind
+ up with the negative of the location within the section,
+ which means we must adjust the existing addend by the change
+ in the location within the section. If pcrel_offset is true
+ we do not want to adjust the existing addend at all.
+
+ FIXME: This seems logical to me, but for the case of
+ producing relocateable output it is not what the code
+ actually does. I don't want to change it, because it seems
+ far too likely that something will break. */
+
+ relocation -=
+ input_section->output_section->vma + input_section->output_offset;
+
+ if (howto->pcrel_offset == true)
+ relocation -= reloc_entry->address;
+ }
+
+ if (output_bfd != (bfd *) NULL)
+ {
+ if (howto->partial_inplace == false)
+ {
+ /* This is a partial relocation, and we want to apply the relocation
+ to the reloc entry rather than the raw data. Modify the reloc
+ inplace to reflect what we now know. */
+ reloc_entry->addend = relocation;
+ reloc_entry->address += input_section->output_offset;
+ return flag;
+ }
+ else
+ {
+ /* This is a partial relocation, but inplace, so modify the
+ reloc record a bit.
+
+ If we've relocated with a symbol with a section, change
+ into a ref to the section belonging to the symbol. */
+
+ reloc_entry->address += input_section->output_offset;
+
+ /* WTF?? */
+ if (abfd->xvec->flavour == bfd_target_coff_flavour
+ && strcmp (abfd->xvec->name, "aixcoff-rs6000") != 0
+ && strcmp (abfd->xvec->name, "xcoff-powermac") != 0
+ && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
+ && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
+ {
+#if 1
+ /* For m68k-coff, the addend was being subtracted twice during
+ relocation with -r. Removing the line below this comment
+ fixes that problem; see PR 2953.
+
+However, Ian wrote the following, regarding removing the line below,
+which explains why it is still enabled: --djm
+
+If you put a patch like that into BFD you need to check all the COFF
+linkers. I am fairly certain that patch will break coff-i386 (e.g.,
+SCO); see coff_i386_reloc in coff-i386.c where I worked around the
+problem in a different way. There may very well be a reason that the
+code works as it does.
+
+Hmmm. The first obvious point is that bfd_perform_relocation should
+not have any tests that depend upon the flavour. It's seem like
+entirely the wrong place for such a thing. The second obvious point
+is that the current code ignores the reloc addend when producing
+relocateable output for COFF. That's peculiar. In fact, I really
+have no idea what the point of the line you want to remove is.
+
+A typical COFF reloc subtracts the old value of the symbol and adds in
+the new value to the location in the object file (if it's a pc
+relative reloc it adds the difference between the symbol value and the
+location). When relocating we need to preserve that property.
+
+BFD handles this by setting the addend to the negative of the old
+value of the symbol. Unfortunately it handles common symbols in a
+non-standard way (it doesn't subtract the old value) but that's a
+different story (we can't change it without losing backward
+compatibility with old object files) (coff-i386 does subtract the old
+value, to be compatible with existing coff-i386 targets, like SCO).
+
+So everything works fine when not producing relocateable output. When
+we are producing relocateable output, logically we should do exactly
+what we do when not producing relocateable output. Therefore, your
+patch is correct. In fact, it should probably always just set
+reloc_entry->addend to 0 for all cases, since it is, in fact, going to
+add the value into the object file. This won't hurt the COFF code,
+which doesn't use the addend; I'm not sure what it will do to other
+formats (the thing to check for would be whether any formats both use
+the addend and set partial_inplace).
+
+When I wanted to make coff-i386 produce relocateable output, I ran
+into the problem that you are running into: I wanted to remove that
+line. Rather than risk it, I made the coff-i386 relocs use a special
+function; it's coff_i386_reloc in coff-i386.c. The function
+specifically adds the addend field into the object file, knowing that
+bfd_perform_relocation is not going to. If you remove that line, then
+coff-i386.c will wind up adding the addend field in twice. It's
+trivial to fix; it just needs to be done.
+
+The problem with removing the line is just that it may break some
+working code. With BFD it's hard to be sure of anything. The right
+way to deal with this is simply to build and test at least all the
+supported COFF targets. It should be straightforward if time and disk
+space consuming. For each target:
+ 1) build the linker
+ 2) generate some executable, and link it using -r (I would
+ probably use paranoia.o and link against newlib/libc.a, which
+ for all the supported targets would be available in
+ /usr/cygnus/progressive/H-host/target/lib/libc.a).
+ 3) make the change to reloc.c
+ 4) rebuild the linker
+ 5) repeat step 2
+ 6) if the resulting object files are the same, you have at least
+ made it no worse
+ 7) if they are different you have to figure out which version is
+ right
+*/
+ relocation -= reloc_entry->addend;
+#endif
+ reloc_entry->addend = 0;
+ }
+ else
+ {
+ reloc_entry->addend = relocation;
+ }
+ }
+ }
+ else
+ {
+ reloc_entry->addend = 0;
+ }
+
+ /* FIXME: This overflow checking is incomplete, because the value
+ might have overflowed before we get here. For a correct check we
+ need to compute the value in a size larger than bitsize, but we
+ can't reasonably do that for a reloc the same size as a host
+ machine word.
+ FIXME: We should also do overflow checking on the result after
+ adding in the value contained in the object file. */
+ if (howto->complain_on_overflow != complain_overflow_dont
+ && flag == bfd_reloc_ok)
+ flag = bfd_check_overflow (howto->complain_on_overflow,
+ howto->bitsize,
+ howto->rightshift,
+ bfd_arch_bits_per_address (abfd),
+ relocation);
+
+ /*
+ Either we are relocating all the way, or we don't want to apply
+ the relocation to the reloc entry (probably because there isn't
+ any room in the output format to describe addends to relocs)
+ */
+
+ /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
+ (OSF version 1.3, compiler version 3.11). It miscompiles the
+ following program:
+
+ struct str
+ {
+ unsigned int i0;
+ } s = { 0 };
+
+ int
+ main ()
+ {
+ unsigned long x;
+
+ x = 0x100000000;
+ x <<= (unsigned long) s.i0;
+ if (x == 0)
+ printf ("failed\n");
+ else
+ printf ("succeeded (%lx)\n", x);
+ }
+ */
+
+ relocation >>= (bfd_vma) howto->rightshift;
+
+ /* Shift everything up to where it's going to be used */
+
+ relocation <<= (bfd_vma) howto->bitpos;
+
+ /* Wait for the day when all have the mask in them */
+
+ /* What we do:
+ i instruction to be left alone
+ o offset within instruction
+ r relocation offset to apply
+ S src mask
+ D dst mask
+ N ~dst mask
+ A part 1
+ B part 2
+ R result
+
+ Do this:
+ i i i i i o o o o o from bfd_get<size>
+ and S S S S S to get the size offset we want
+ + r r r r r r r r r r to get the final value to place
+ and D D D D D to chop to right size
+ -----------------------
+ A A A A A
+ And this:
+ ... i i i i i o o o o o from bfd_get<size>
+ and N N N N N get instruction
+ -----------------------
+ ... B B B B B
+
+ And then:
+ B B B B B
+ or A A A A A
+ -----------------------
+ R R R R R R R R R R put into bfd_put<size>
+ */
+
+#define DOIT(x) \
+ x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
+
+ switch (howto->size)
+ {
+ case 0:
+ {
+ char x = bfd_get_8 (abfd, (char *) data + addr);
+ DOIT (x);
+ bfd_put_8 (abfd, x, (unsigned char *) data + addr);
+ }
+ break;
+
+ case 1:
+ {
+ short x = bfd_get_16 (abfd, (bfd_byte *) data + addr);
+ DOIT (x);
+ bfd_put_16 (abfd, x, (unsigned char *) data + addr);
+ }
+ break;
+ case 2:
+ {
+ long x = bfd_get_32 (abfd, (bfd_byte *) data + addr);
+ DOIT (x);
+ bfd_put_32 (abfd, x, (bfd_byte *) data + addr);
+ }
+ break;
+ case -2:
+ {
+ long x = bfd_get_32 (abfd, (bfd_byte *) data + addr);
+ relocation = -relocation;
+ DOIT (x);
+ bfd_put_32 (abfd, x, (bfd_byte *) data + addr);
+ }
+ break;
+
+ case -1:
+ {
+ long x = bfd_get_16 (abfd, (bfd_byte *) data + addr);
+ relocation = -relocation;
+ DOIT (x);
+ bfd_put_16 (abfd, x, (bfd_byte *) data + addr);
+ }
+ break;
+
+ case 3:
+ /* Do nothing */
+ break;
+
+ case 4:
+#ifdef BFD64
+ {
+ bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data + addr);
+ DOIT (x);
+ bfd_put_64 (abfd, x, (bfd_byte *) data + addr);
+ }
+#else
+ abort ();
+#endif
+ break;
+ default:
+ return bfd_reloc_other;
+ }
+
+ return flag;
+}
+
+/*
+FUNCTION
+ bfd_install_relocation
+
+SYNOPSIS
+ bfd_reloc_status_type
+ bfd_install_relocation
+ (bfd *abfd,
+ arelent *reloc_entry,
+ PTR data, bfd_vma data_start,
+ asection *input_section,
+ char **error_message);
+
+DESCRIPTION
+ This looks remarkably like <<bfd_perform_relocation>>, except it
+ does not expect that the section contents have been filled in.
+ I.e., it's suitable for use when creating, rather than applying
+ a relocation.
+
+ For now, this function should be considered reserved for the
+ assembler.
+
+*/
+
+
+bfd_reloc_status_type
+bfd_install_relocation (abfd, reloc_entry, data_start, data_start_offset,
+ input_section, error_message)
+ bfd *abfd;
+ arelent *reloc_entry;
+ PTR data_start;
+ bfd_vma data_start_offset;
+ asection *input_section;
+ char **error_message;
+{
+ bfd_vma relocation;
+ bfd_reloc_status_type flag = bfd_reloc_ok;
+ bfd_size_type addr = reloc_entry->address;
+ bfd_vma output_base = 0;
+ reloc_howto_type *howto = reloc_entry->howto;
+ asection *reloc_target_output_section;
+ asymbol *symbol;
+ bfd_byte *data;
+
+ symbol = *(reloc_entry->sym_ptr_ptr);
+ if (bfd_is_abs_section (symbol->section))
+ {
+ reloc_entry->address += input_section->output_offset;
+ return bfd_reloc_ok;
+ }
+
+ /* If there is a function supplied to handle this relocation type,
+ call it. It'll return `bfd_reloc_continue' if further processing
+ can be done. */
+ if (howto->special_function)
+ {
+ bfd_reloc_status_type cont;
+
+ /* XXX - The special_function calls haven't been fixed up to deal
+ with creating new relocations and section contents. */
+ cont = howto->special_function (abfd, reloc_entry, symbol,
+ /* XXX - Non-portable! */
+ ((bfd_byte *) data_start
+ - data_start_offset),
+ input_section, abfd, error_message);
+ if (cont != bfd_reloc_continue)
+ return cont;
+ }
+
+ /* Is the address of the relocation really within the section? */
+ if (reloc_entry->address > input_section->_cooked_size)
+ return bfd_reloc_outofrange;
+
+ /* Work out which section the relocation is targetted at and the
+ initial relocation command value. */
+
+ /* Get symbol value. (Common symbols are special.) */
+ if (bfd_is_com_section (symbol->section))
+ relocation = 0;
+ else
+ relocation = symbol->value;
+
+ reloc_target_output_section = symbol->section->output_section;
+
+ /* Convert input-section-relative symbol value to absolute. */
+ if (howto->partial_inplace == false)
+ output_base = 0;
+ else
+ output_base = reloc_target_output_section->vma;
+
+ relocation += output_base + symbol->section->output_offset;
+
+ /* Add in supplied addend. */
+ relocation += reloc_entry->addend;
+
+ /* Here the variable relocation holds the final address of the
+ symbol we are relocating against, plus any addend. */
+
+ if (howto->pc_relative == true)
+ {
+ /* This is a PC relative relocation. We want to set RELOCATION
+ to the distance between the address of the symbol and the
+ location. RELOCATION is already the address of the symbol.
+
+ We start by subtracting the address of the section containing
+ the location.
+
+ If pcrel_offset is set, we must further subtract the position
+ of the location within the section. Some targets arrange for
+ the addend to be the negative of the position of the location
+ within the section; for example, i386-aout does this. For
+ i386-aout, pcrel_offset is false. Some other targets do not
+ include the position of the location; for example, m88kbcs,
+ or ELF. For those targets, pcrel_offset is true.
+
+ If we are producing relocateable output, then we must ensure
+ that this reloc will be correctly computed when the final
+ relocation is done. If pcrel_offset is false we want to wind
+ up with the negative of the location within the section,
+ which means we must adjust the existing addend by the change
+ in the location within the section. If pcrel_offset is true
+ we do not want to adjust the existing addend at all.
+
+ FIXME: This seems logical to me, but for the case of
+ producing relocateable output it is not what the code
+ actually does. I don't want to change it, because it seems
+ far too likely that something will break. */
+
+ relocation -=
+ input_section->output_section->vma + input_section->output_offset;
+
+ if (howto->pcrel_offset == true && howto->partial_inplace == true)
+ relocation -= reloc_entry->address;
+ }
+
+ if (howto->partial_inplace == false)
+ {
+ /* This is a partial relocation, and we want to apply the relocation
+ to the reloc entry rather than the raw data. Modify the reloc
+ inplace to reflect what we now know. */
+ reloc_entry->addend = relocation;
+ reloc_entry->address += input_section->output_offset;
+ return flag;
+ }
+ else
+ {
+ /* This is a partial relocation, but inplace, so modify the
+ reloc record a bit.
+
+ If we've relocated with a symbol with a section, change
+ into a ref to the section belonging to the symbol. */
+
+ reloc_entry->address += input_section->output_offset;
+
+ /* WTF?? */
+ if (abfd->xvec->flavour == bfd_target_coff_flavour
+ && strcmp (abfd->xvec->name, "aixcoff-rs6000") != 0
+ && strcmp (abfd->xvec->name, "xcoff-powermac") != 0
+ && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
+ && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
+ {
+#if 1
+/* For m68k-coff, the addend was being subtracted twice during
+ relocation with -r. Removing the line below this comment
+ fixes that problem; see PR 2953.
+
+However, Ian wrote the following, regarding removing the line below,
+which explains why it is still enabled: --djm
+
+If you put a patch like that into BFD you need to check all the COFF
+linkers. I am fairly certain that patch will break coff-i386 (e.g.,
+SCO); see coff_i386_reloc in coff-i386.c where I worked around the
+problem in a different way. There may very well be a reason that the
+code works as it does.
+
+Hmmm. The first obvious point is that bfd_install_relocation should
+not have any tests that depend upon the flavour. It's seem like
+entirely the wrong place for such a thing. The second obvious point
+is that the current code ignores the reloc addend when producing
+relocateable output for COFF. That's peculiar. In fact, I really
+have no idea what the point of the line you want to remove is.
+
+A typical COFF reloc subtracts the old value of the symbol and adds in
+the new value to the location in the object file (if it's a pc
+relative reloc it adds the difference between the symbol value and the
+location). When relocating we need to preserve that property.
+
+BFD handles this by setting the addend to the negative of the old
+value of the symbol. Unfortunately it handles common symbols in a
+non-standard way (it doesn't subtract the old value) but that's a
+different story (we can't change it without losing backward
+compatibility with old object files) (coff-i386 does subtract the old
+value, to be compatible with existing coff-i386 targets, like SCO).
+
+So everything works fine when not producing relocateable output. When
+we are producing relocateable output, logically we should do exactly
+what we do when not producing relocateable output. Therefore, your
+patch is correct. In fact, it should probably always just set
+reloc_entry->addend to 0 for all cases, since it is, in fact, going to
+add the value into the object file. This won't hurt the COFF code,
+which doesn't use the addend; I'm not sure what it will do to other
+formats (the thing to check for would be whether any formats both use
+the addend and set partial_inplace).
+
+When I wanted to make coff-i386 produce relocateable output, I ran
+into the problem that you are running into: I wanted to remove that
+line. Rather than risk it, I made the coff-i386 relocs use a special
+function; it's coff_i386_reloc in coff-i386.c. The function
+specifically adds the addend field into the object file, knowing that
+bfd_install_relocation is not going to. If you remove that line, then
+coff-i386.c will wind up adding the addend field in twice. It's
+trivial to fix; it just needs to be done.
+
+The problem with removing the line is just that it may break some
+working code. With BFD it's hard to be sure of anything. The right
+way to deal with this is simply to build and test at least all the
+supported COFF targets. It should be straightforward if time and disk
+space consuming. For each target:
+ 1) build the linker
+ 2) generate some executable, and link it using -r (I would
+ probably use paranoia.o and link against newlib/libc.a, which
+ for all the supported targets would be available in
+ /usr/cygnus/progressive/H-host/target/lib/libc.a).
+ 3) make the change to reloc.c
+ 4) rebuild the linker
+ 5) repeat step 2
+ 6) if the resulting object files are the same, you have at least
+ made it no worse
+ 7) if they are different you have to figure out which version is
+ right
+*/
+ relocation -= reloc_entry->addend;
+#endif
+ reloc_entry->addend = 0;
+ }
+ else
+ {
+ reloc_entry->addend = relocation;
+ }
+ }
+
+ /* FIXME: This overflow checking is incomplete, because the value
+ might have overflowed before we get here. For a correct check we
+ need to compute the value in a size larger than bitsize, but we
+ can't reasonably do that for a reloc the same size as a host
+ machine word.
+ FIXME: We should also do overflow checking on the result after
+ adding in the value contained in the object file. */
+ if (howto->complain_on_overflow != complain_overflow_dont)
+ flag = bfd_check_overflow (howto->complain_on_overflow,
+ howto->bitsize,
+ howto->rightshift,
+ bfd_arch_bits_per_address (abfd),
+ relocation);
+
+ /*
+ Either we are relocating all the way, or we don't want to apply
+ the relocation to the reloc entry (probably because there isn't
+ any room in the output format to describe addends to relocs)
+ */
+
+ /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
+ (OSF version 1.3, compiler version 3.11). It miscompiles the
+ following program:
+
+ struct str
+ {
+ unsigned int i0;
+ } s = { 0 };
+
+ int
+ main ()
+ {
+ unsigned long x;
+
+ x = 0x100000000;
+ x <<= (unsigned long) s.i0;
+ if (x == 0)
+ printf ("failed\n");
+ else
+ printf ("succeeded (%lx)\n", x);
+ }
+ */
+
+ relocation >>= (bfd_vma) howto->rightshift;
+
+ /* Shift everything up to where it's going to be used */
+
+ relocation <<= (bfd_vma) howto->bitpos;
+
+ /* Wait for the day when all have the mask in them */
+
+ /* What we do:
+ i instruction to be left alone
+ o offset within instruction
+ r relocation offset to apply
+ S src mask
+ D dst mask
+ N ~dst mask
+ A part 1
+ B part 2
+ R result
+
+ Do this:
+ i i i i i o o o o o from bfd_get<size>
+ and S S S S S to get the size offset we want
+ + r r r r r r r r r r to get the final value to place
+ and D D D D D to chop to right size
+ -----------------------
+ A A A A A
+ And this:
+ ... i i i i i o o o o o from bfd_get<size>
+ and N N N N N get instruction
+ -----------------------
+ ... B B B B B
+
+ And then:
+ B B B B B
+ or A A A A A
+ -----------------------
+ R R R R R R R R R R put into bfd_put<size>
+ */
+
+#define DOIT(x) \
+ x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
+
+ data = (bfd_byte *) data_start + (addr - data_start_offset);
+
+ switch (howto->size)
+ {
+ case 0:
+ {
+ char x = bfd_get_8 (abfd, (char *) data);
+ DOIT (x);
+ bfd_put_8 (abfd, x, (unsigned char *) data);
+ }
+ break;
+
+ case 1:
+ {
+ short x = bfd_get_16 (abfd, (bfd_byte *) data);
+ DOIT (x);
+ bfd_put_16 (abfd, x, (unsigned char *) data);
+ }
+ break;
+ case 2:
+ {
+ long x = bfd_get_32 (abfd, (bfd_byte *) data);
+ DOIT (x);
+ bfd_put_32 (abfd, x, (bfd_byte *) data);
+ }
+ break;
+ case -2:
+ {
+ long x = bfd_get_32 (abfd, (bfd_byte *) data);
+ relocation = -relocation;
+ DOIT (x);
+ bfd_put_32 (abfd, x, (bfd_byte *) data);
+ }
+ break;
+
+ case 3:
+ /* Do nothing */
+ break;
+
+ case 4:
+ {
+ bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data);
+ DOIT (x);
+ bfd_put_64 (abfd, x, (bfd_byte *) data);
+ }
+ break;
+ default:
+ return bfd_reloc_other;
+ }
+
+ return flag;
+}
+
+/* This relocation routine is used by some of the backend linkers.
+ They do not construct asymbol or arelent structures, so there is no
+ reason for them to use bfd_perform_relocation. Also,
+ bfd_perform_relocation is so hacked up it is easier to write a new
+ function than to try to deal with it.
+
+ This routine does a final relocation. Whether it is useful for a
+ relocateable link depends upon how the object format defines
+ relocations.
+
+ FIXME: This routine ignores any special_function in the HOWTO,
+ since the existing special_function values have been written for
+ bfd_perform_relocation.
+
+ HOWTO is the reloc howto information.
+ INPUT_BFD is the BFD which the reloc applies to.
+ INPUT_SECTION is the section which the reloc applies to.
+ CONTENTS is the contents of the section.
+ ADDRESS is the address of the reloc within INPUT_SECTION.
+ VALUE is the value of the symbol the reloc refers to.
+ ADDEND is the addend of the reloc. */
+
+bfd_reloc_status_type
+_bfd_final_link_relocate (howto, input_bfd, input_section, contents, address,
+ value, addend)
+ reloc_howto_type *howto;
+ bfd *input_bfd;
+ asection *input_section;
+ bfd_byte *contents;
+ bfd_vma address;
+ bfd_vma value;
+ bfd_vma addend;
+{
+ bfd_vma relocation;
+
+ /* Sanity check the address. */
+ if (address > input_section->_raw_size)
+ return bfd_reloc_outofrange;
+
+ /* This function assumes that we are dealing with a basic relocation
+ against a symbol. We want to compute the value of the symbol to
+ relocate to. This is just VALUE, the value of the symbol, plus
+ ADDEND, any addend associated with the reloc. */
+ relocation = value + addend;
+
+ /* If the relocation is PC relative, we want to set RELOCATION to
+ the distance between the symbol (currently in RELOCATION) and the
+ location we are relocating. Some targets (e.g., i386-aout)
+ arrange for the contents of the section to be the negative of the
+ offset of the location within the section; for such targets
+ pcrel_offset is false. Other targets (e.g., m88kbcs or ELF)
+ simply leave the contents of the section as zero; for such
+ targets pcrel_offset is true. If pcrel_offset is false we do not
+ need to subtract out the offset of the location within the
+ section (which is just ADDRESS). */
+ if (howto->pc_relative)
+ {
+ relocation -= (input_section->output_section->vma
+ + input_section->output_offset);
+ if (howto->pcrel_offset)
+ relocation -= address;
+ }
+
+ return _bfd_relocate_contents (howto, input_bfd, relocation,
+ contents + address);
+}
+
+/* Relocate a given location using a given value and howto. */
+
+bfd_reloc_status_type
+_bfd_relocate_contents (howto, input_bfd, relocation, location)
+ reloc_howto_type *howto;
+ bfd *input_bfd;
+ bfd_vma relocation;
+ bfd_byte *location;
+{
+ int size;
+ bfd_vma x;
+ boolean overflow;
+ unsigned int rightshift = howto->rightshift;
+ unsigned int bitpos = howto->bitpos;
+
+ /* If the size is negative, negate RELOCATION. This isn't very
+ general. */
+ if (howto->size < 0)
+ relocation = -relocation;
+
+ /* Get the value we are going to relocate. */
+ size = bfd_get_reloc_size (howto);
+ switch (size)
+ {
+ default:
+ case 0:
+ abort ();
+ case 1:
+ x = bfd_get_8 (input_bfd, location);
+ break;
+ case 2:
+ x = bfd_get_16 (input_bfd, location);
+ break;
+ case 4:
+ x = bfd_get_32 (input_bfd, location);
+ break;
+ case 8:
+#ifdef BFD64
+ x = bfd_get_64 (input_bfd, location);
+#else
+ abort ();
+#endif
+ break;
+ }
+
+ /* Check for overflow. FIXME: We may drop bits during the addition
+ which we don't check for. We must either check at every single
+ operation, which would be tedious, or we must do the computations
+ in a type larger than bfd_vma, which would be inefficient. */
+ overflow = false;
+ if (howto->complain_on_overflow != complain_overflow_dont)
+ {
+ bfd_vma addrmask, fieldmask, signmask, ss;
+ bfd_vma a, b, sum;
+
+ /* Get the values to be added together. For signed and unsigned
+ relocations, we assume that all values should be truncated to
+ the size of an address. For bitfields, all the bits matter.
+ See also bfd_check_overflow. */
+ fieldmask = N_ONES (howto->bitsize);
+ addrmask = N_ONES (bfd_arch_bits_per_address (input_bfd)) | fieldmask;
+ a = relocation;
+ b = x & howto->src_mask;
+
+ switch (howto->complain_on_overflow)
+ {
+ case complain_overflow_signed:
+ a = (a & addrmask) >> rightshift;
+
+ /* If any sign bits are set, all sign bits must be set.
+ That is, A must be a valid negative address after
+ shifting. */
+ signmask = ~ (fieldmask >> 1);
+ ss = a & signmask;
+ if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
+ overflow = true;
+
+ /* We only need this next bit of code if the sign bit of B
+ is below the sign bit of A. This would only happen if
+ SRC_MASK had fewer bits than BITSIZE. Note that if
+ SRC_MASK has more bits than BITSIZE, we can get into
+ trouble; we would need to verify that B is in range, as
+ we do for A above. */
+ signmask = ((~ howto->src_mask) >> 1) & howto->src_mask;
+ if ((b & signmask) != 0)
+ {
+ /* Set all the bits above the sign bit. */
+ b -= signmask <<= 1;
+ }
+
+ b = (b & addrmask) >> bitpos;
+
+ /* Now we can do the addition. */
+ sum = a + b;
+
+ /* See if the result has the correct sign. Bits above the
+ sign bit are junk now; ignore them. If the sum is
+ positive, make sure we did not have all negative inputs;
+ if the sum is negative, make sure we did not have all
+ positive inputs. The test below looks only at the sign
+ bits, and it really just
+ SIGN (A) == SIGN (B) && SIGN (A) != SIGN (SUM)
+ */
+ signmask = (fieldmask >> 1) + 1;
+ if (((~ (a ^ b)) & (a ^ sum)) & signmask)
+ overflow = true;
+
+ break;
+
+ case complain_overflow_unsigned:
+ /* Checking for an unsigned overflow is relatively easy:
+ trim the addresses and add, and trim the result as well.
+ Overflow is normally indicated when the result does not
+ fit in the field. However, we also need to consider the
+ case when, e.g., fieldmask is 0x7fffffff or smaller, an
+ input is 0x80000000, and bfd_vma is only 32 bits; then we
+ will get sum == 0, but there is an overflow, since the
+ inputs did not fit in the field. Instead of doing a
+ separate test, we can check for this by or-ing in the
+ operands when testing for the sum overflowing its final
+ field. */
+ a = (a & addrmask) >> rightshift;
+ b = (b & addrmask) >> bitpos;
+ sum = (a + b) & addrmask;
+ if ((a | b | sum) & ~ fieldmask)
+ overflow = true;
+
+ break;
+
+ case complain_overflow_bitfield:
+ /* Much like unsigned, except no trimming with addrmask. In
+ addition, the sum overflows if there is a carry out of
+ the bfd_vma, i.e., the sum is less than either input
+ operand. */
+ a >>= rightshift;
+ b >>= bitpos;
+
+ /* Bitfields are sometimes used for signed numbers; for
+ example, a 13-bit field sometimes represents values in
+ 0..8191 and sometimes represents values in -4096..4095.
+ If the field is signed and a is -4095 (0x1001) and b is
+ -1 (0x1fff), the sum is -4096 (0x1000), but (0x1001 +
+ 0x1fff is 0x3000). It's not clear how to handle this
+ everywhere, since there is not way to know how many bits
+ are significant in the relocation, but the original code
+ assumed that it was fully sign extended, and we will keep
+ that assumption. */
+ signmask = (fieldmask >> 1) + 1;
+
+ if ((a & ~ fieldmask) != 0)
+ {
+ /* Some bits out of the field are set. This might not
+ be a problem: if this is a signed bitfield, it is OK
+ iff all the high bits are set, including the sign
+ bit. We'll try setting all but the most significant
+ bit in the original relocation value: if this is all
+ ones, we are OK, assuming a signed bitfield. */
+ ss = (signmask << rightshift) - 1;
+ if ((ss | relocation) != ~ (bfd_vma) 0)
+ overflow = true;
+ a &= fieldmask;
+ }
+
+ /* We just assume (b & ~ fieldmask) == 0. */
+
+ sum = a + b;
+ if (sum < a || (sum & ~ fieldmask) != 0)
+ {
+ /* There was a carry out, or the field overflow. Test
+ for signed operands again. Here is the overflow test
+ is as for complain_overflow_signed. */
+ if (((~ (a ^ b)) & (a ^ sum)) & signmask)
+ overflow = true;
+ }
+
+ break;
+
+ default:
+ abort ();
+ }
+ }
+
+ /* Put RELOCATION in the right bits. */
+ relocation >>= (bfd_vma) rightshift;
+ relocation <<= (bfd_vma) bitpos;
+
+ /* Add RELOCATION to the right bits of X. */
+ x = ((x & ~howto->dst_mask)
+ | (((x & howto->src_mask) + relocation) & howto->dst_mask));
+
+ /* Put the relocated value back in the object file. */
+ switch (size)
+ {
+ default:
+ case 0:
+ abort ();
+ case 1:
+ bfd_put_8 (input_bfd, x, location);
+ break;
+ case 2:
+ bfd_put_16 (input_bfd, x, location);
+ break;
+ case 4:
+ bfd_put_32 (input_bfd, x, location);
+ break;
+ case 8:
+#ifdef BFD64
+ bfd_put_64 (input_bfd, x, location);
+#else
+ abort ();
+#endif
+ break;
+ }
+
+ return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
+}
+
+/*
+DOCDD
+INODE
+ howto manager, , typedef arelent, Relocations
+
+SECTION
+ The howto manager
+
+ When an application wants to create a relocation, but doesn't
+ know what the target machine might call it, it can find out by
+ using this bit of code.
+
+*/
+
+/*
+TYPEDEF
+ bfd_reloc_code_type
+
+DESCRIPTION
+ The insides of a reloc code. The idea is that, eventually, there
+ will be one enumerator for every type of relocation we ever do.
+ Pass one of these values to <<bfd_reloc_type_lookup>>, and it'll
+ return a howto pointer.
+
+ This does mean that the application must determine the correct
+ enumerator value; you can't get a howto pointer from a random set
+ of attributes.
+
+SENUM
+ bfd_reloc_code_real
+
+ENUM
+ BFD_RELOC_64
+ENUMX
+ BFD_RELOC_32
+ENUMX
+ BFD_RELOC_26
+ENUMX
+ BFD_RELOC_24
+ENUMX
+ BFD_RELOC_16
+ENUMX
+ BFD_RELOC_14
+ENUMX
+ BFD_RELOC_8
+ENUMDOC
+ Basic absolute relocations of N bits.
+
+ENUM
+ BFD_RELOC_64_PCREL
+ENUMX
+ BFD_RELOC_32_PCREL
+ENUMX
+ BFD_RELOC_24_PCREL
+ENUMX
+ BFD_RELOC_16_PCREL
+ENUMX
+ BFD_RELOC_12_PCREL
+ENUMX
+ BFD_RELOC_8_PCREL
+ENUMDOC
+ PC-relative relocations. Sometimes these are relative to the address
+of the relocation itself; sometimes they are relative to the start of
+the section containing the relocation. It depends on the specific target.
+
+The 24-bit relocation is used in some Intel 960 configurations.
+
+ENUM
+ BFD_RELOC_32_GOT_PCREL
+ENUMX
+ BFD_RELOC_16_GOT_PCREL
+ENUMX
+ BFD_RELOC_8_GOT_PCREL
+ENUMX
+ BFD_RELOC_32_GOTOFF
+ENUMX
+ BFD_RELOC_16_GOTOFF
+ENUMX
+ BFD_RELOC_LO16_GOTOFF
+ENUMX
+ BFD_RELOC_HI16_GOTOFF
+ENUMX
+ BFD_RELOC_HI16_S_GOTOFF
+ENUMX
+ BFD_RELOC_8_GOTOFF
+ENUMX
+ BFD_RELOC_32_PLT_PCREL
+ENUMX
+ BFD_RELOC_24_PLT_PCREL
+ENUMX
+ BFD_RELOC_16_PLT_PCREL
+ENUMX
+ BFD_RELOC_8_PLT_PCREL
+ENUMX
+ BFD_RELOC_32_PLTOFF
+ENUMX
+ BFD_RELOC_16_PLTOFF
+ENUMX
+ BFD_RELOC_LO16_PLTOFF
+ENUMX
+ BFD_RELOC_HI16_PLTOFF
+ENUMX
+ BFD_RELOC_HI16_S_PLTOFF
+ENUMX
+ BFD_RELOC_8_PLTOFF
+ENUMDOC
+ For ELF.
+
+ENUM
+ BFD_RELOC_68K_GLOB_DAT
+ENUMX
+ BFD_RELOC_68K_JMP_SLOT
+ENUMX
+ BFD_RELOC_68K_RELATIVE
+ENUMDOC
+ Relocations used by 68K ELF.
+
+ENUM
+ BFD_RELOC_32_BASEREL
+ENUMX
+ BFD_RELOC_16_BASEREL
+ENUMX
+ BFD_RELOC_LO16_BASEREL
+ENUMX
+ BFD_RELOC_HI16_BASEREL
+ENUMX
+ BFD_RELOC_HI16_S_BASEREL
+ENUMX
+ BFD_RELOC_8_BASEREL
+ENUMX
+ BFD_RELOC_RVA
+ENUMDOC
+ Linkage-table relative.
+
+ENUM
+ BFD_RELOC_8_FFnn
+ENUMDOC
+ Absolute 8-bit relocation, but used to form an address like 0xFFnn.
+
+ENUM
+ BFD_RELOC_32_PCREL_S2
+ENUMX
+ BFD_RELOC_16_PCREL_S2
+ENUMX
+ BFD_RELOC_23_PCREL_S2
+ENUMDOC
+ These PC-relative relocations are stored as word displacements --
+i.e., byte displacements shifted right two bits. The 30-bit word
+displacement (<<32_PCREL_S2>> -- 32 bits, shifted 2) is used on the
+SPARC. (SPARC tools generally refer to this as <<WDISP30>>.) The
+signed 16-bit displacement is used on the MIPS, and the 23-bit
+displacement is used on the Alpha.
+
+ENUM
+ BFD_RELOC_HI22
+ENUMX
+ BFD_RELOC_LO10
+ENUMDOC
+ High 22 bits and low 10 bits of 32-bit value, placed into lower bits of
+the target word. These are used on the SPARC.
+
+ENUM
+ BFD_RELOC_GPREL16
+ENUMX
+ BFD_RELOC_GPREL32
+ENUMDOC
+ For systems that allocate a Global Pointer register, these are
+displacements off that register. These relocation types are
+handled specially, because the value the register will have is
+decided relatively late.
+
+
+ENUM
+ BFD_RELOC_I960_CALLJ
+ENUMDOC
+ Reloc types used for i960/b.out.
+
+ENUM
+ BFD_RELOC_NONE
+ENUMX
+ BFD_RELOC_SPARC_WDISP22
+ENUMX
+ BFD_RELOC_SPARC22
+ENUMX
+ BFD_RELOC_SPARC13
+ENUMX
+ BFD_RELOC_SPARC_GOT10
+ENUMX
+ BFD_RELOC_SPARC_GOT13
+ENUMX
+ BFD_RELOC_SPARC_GOT22
+ENUMX
+ BFD_RELOC_SPARC_PC10
+ENUMX
+ BFD_RELOC_SPARC_PC22
+ENUMX
+ BFD_RELOC_SPARC_WPLT30
+ENUMX
+ BFD_RELOC_SPARC_COPY
+ENUMX
+ BFD_RELOC_SPARC_GLOB_DAT
+ENUMX
+ BFD_RELOC_SPARC_JMP_SLOT
+ENUMX
+ BFD_RELOC_SPARC_RELATIVE
+ENUMX
+ BFD_RELOC_SPARC_UA32
+ENUMDOC
+ SPARC ELF relocations. There is probably some overlap with other
+ relocation types already defined.
+
+ENUM
+ BFD_RELOC_SPARC_BASE13
+ENUMX
+ BFD_RELOC_SPARC_BASE22
+ENUMDOC
+ I think these are specific to SPARC a.out (e.g., Sun 4).
+
+ENUMEQ
+ BFD_RELOC_SPARC_64
+ BFD_RELOC_64
+ENUMX
+ BFD_RELOC_SPARC_10
+ENUMX
+ BFD_RELOC_SPARC_11
+ENUMX
+ BFD_RELOC_SPARC_OLO10
+ENUMX
+ BFD_RELOC_SPARC_HH22
+ENUMX
+ BFD_RELOC_SPARC_HM10
+ENUMX
+ BFD_RELOC_SPARC_LM22
+ENUMX
+ BFD_RELOC_SPARC_PC_HH22
+ENUMX
+ BFD_RELOC_SPARC_PC_HM10
+ENUMX
+ BFD_RELOC_SPARC_PC_LM22
+ENUMX
+ BFD_RELOC_SPARC_WDISP16
+ENUMX
+ BFD_RELOC_SPARC_WDISP19
+ENUMX
+ BFD_RELOC_SPARC_7
+ENUMX
+ BFD_RELOC_SPARC_6
+ENUMX
+ BFD_RELOC_SPARC_5
+ENUMEQX
+ BFD_RELOC_SPARC_DISP64
+ BFD_RELOC_64_PCREL
+ENUMX
+ BFD_RELOC_SPARC_PLT64
+ENUMX
+ BFD_RELOC_SPARC_HIX22
+ENUMX
+ BFD_RELOC_SPARC_LOX10
+ENUMX
+ BFD_RELOC_SPARC_H44
+ENUMX
+ BFD_RELOC_SPARC_M44
+ENUMX
+ BFD_RELOC_SPARC_L44
+ENUMX
+ BFD_RELOC_SPARC_REGISTER
+ENUMDOC
+ SPARC64 relocations
+
+ENUM
+ BFD_RELOC_SPARC_REV32
+ENUMDOC
+ SPARC little endian relocation
+
+ENUM
+ BFD_RELOC_ALPHA_GPDISP_HI16
+ENUMDOC
+ Alpha ECOFF and ELF relocations. Some of these treat the symbol or
+ "addend" in some special way.
+ For GPDISP_HI16 ("gpdisp") relocations, the symbol is ignored when
+ writing; when reading, it will be the absolute section symbol. The
+ addend is the displacement in bytes of the "lda" instruction from
+ the "ldah" instruction (which is at the address of this reloc).
+ENUM
+ BFD_RELOC_ALPHA_GPDISP_LO16
+ENUMDOC
+ For GPDISP_LO16 ("ignore") relocations, the symbol is handled as
+ with GPDISP_HI16 relocs. The addend is ignored when writing the
+ relocations out, and is filled in with the file's GP value on
+ reading, for convenience.
+
+ENUM
+ BFD_RELOC_ALPHA_GPDISP
+ENUMDOC
+ The ELF GPDISP relocation is exactly the same as the GPDISP_HI16
+ relocation except that there is no accompanying GPDISP_LO16
+ relocation.
+
+ENUM
+ BFD_RELOC_ALPHA_LITERAL
+ENUMX
+ BFD_RELOC_ALPHA_ELF_LITERAL
+ENUMX
+ BFD_RELOC_ALPHA_LITUSE
+ENUMDOC
+ The Alpha LITERAL/LITUSE relocs are produced by a symbol reference;
+ the assembler turns it into a LDQ instruction to load the address of
+ the symbol, and then fills in a register in the real instruction.
+
+ The LITERAL reloc, at the LDQ instruction, refers to the .lita
+ section symbol. The addend is ignored when writing, but is filled
+ in with the file's GP value on reading, for convenience, as with the
+ GPDISP_LO16 reloc.
+
+ The ELF_LITERAL reloc is somewhere between 16_GOTOFF and GPDISP_LO16.
+ It should refer to the symbol to be referenced, as with 16_GOTOFF,
+ but it generates output not based on the position within the .got
+ section, but relative to the GP value chosen for the file during the
+ final link stage.
+
+ The LITUSE reloc, on the instruction using the loaded address, gives
+ information to the linker that it might be able to use to optimize
+ away some literal section references. The symbol is ignored (read
+ as the absolute section symbol), and the "addend" indicates the type
+ of instruction using the register:
+ 1 - "memory" fmt insn
+ 2 - byte-manipulation (byte offset reg)
+ 3 - jsr (target of branch)
+
+ The GNU linker currently doesn't do any of this optimizing.
+
+ENUM
+ BFD_RELOC_ALPHA_HINT
+ENUMDOC
+ The HINT relocation indicates a value that should be filled into the
+ "hint" field of a jmp/jsr/ret instruction, for possible branch-
+ prediction logic which may be provided on some processors.
+
+ENUM
+ BFD_RELOC_ALPHA_LINKAGE
+ENUMDOC
+ The LINKAGE relocation outputs a linkage pair in the object file,
+ which is filled by the linker.
+
+ENUM
+ BFD_RELOC_ALPHA_CODEADDR
+ENUMDOC
+ The CODEADDR relocation outputs a STO_CA in the object file,
+ which is filled by the linker.
+
+ENUM
+ BFD_RELOC_MIPS_JMP
+ENUMDOC
+ Bits 27..2 of the relocation address shifted right 2 bits;
+ simple reloc otherwise.
+
+ENUM
+ BFD_RELOC_MIPS16_JMP
+ENUMDOC
+ The MIPS16 jump instruction.
+
+ENUM
+ BFD_RELOC_MIPS16_GPREL
+ENUMDOC
+ MIPS16 GP relative reloc.
+
+ENUM
+ BFD_RELOC_HI16
+ENUMDOC
+ High 16 bits of 32-bit value; simple reloc.
+ENUM
+ BFD_RELOC_HI16_S
+ENUMDOC
+ High 16 bits of 32-bit value but the low 16 bits will be sign
+ extended and added to form the final result. If the low 16
+ bits form a negative number, we need to add one to the high value
+ to compensate for the borrow when the low bits are added.
+ENUM
+ BFD_RELOC_LO16
+ENUMDOC
+ Low 16 bits.
+ENUM
+ BFD_RELOC_PCREL_HI16_S
+ENUMDOC
+ Like BFD_RELOC_HI16_S, but PC relative.
+ENUM
+ BFD_RELOC_PCREL_LO16
+ENUMDOC
+ Like BFD_RELOC_LO16, but PC relative.
+
+ENUMEQ
+ BFD_RELOC_MIPS_GPREL
+ BFD_RELOC_GPREL16
+ENUMDOC
+ Relocation relative to the global pointer.
+
+ENUM
+ BFD_RELOC_MIPS_LITERAL
+ENUMDOC
+ Relocation against a MIPS literal section.
+
+ENUM
+ BFD_RELOC_MIPS_GOT16
+ENUMX
+ BFD_RELOC_MIPS_CALL16
+ENUMEQX
+ BFD_RELOC_MIPS_GPREL32
+ BFD_RELOC_GPREL32
+ENUMX
+ BFD_RELOC_MIPS_GOT_HI16
+ENUMX
+ BFD_RELOC_MIPS_GOT_LO16
+ENUMX
+ BFD_RELOC_MIPS_CALL_HI16
+ENUMX
+ BFD_RELOC_MIPS_CALL_LO16
+COMMENT
+ENUMDOC
+ MIPS ELF relocations.
+
+COMMENT
+
+ENUM
+ BFD_RELOC_386_GOT32
+ENUMX
+ BFD_RELOC_386_PLT32
+ENUMX
+ BFD_RELOC_386_COPY
+ENUMX
+ BFD_RELOC_386_GLOB_DAT
+ENUMX
+ BFD_RELOC_386_JUMP_SLOT
+ENUMX
+ BFD_RELOC_386_RELATIVE
+ENUMX
+ BFD_RELOC_386_GOTOFF
+ENUMX
+ BFD_RELOC_386_GOTPC
+ENUMDOC
+ i386/elf relocations
+
+ENUM
+ BFD_RELOC_NS32K_IMM_8
+ENUMX
+ BFD_RELOC_NS32K_IMM_16
+ENUMX
+ BFD_RELOC_NS32K_IMM_32
+ENUMX
+ BFD_RELOC_NS32K_IMM_8_PCREL
+ENUMX
+ BFD_RELOC_NS32K_IMM_16_PCREL
+ENUMX
+ BFD_RELOC_NS32K_IMM_32_PCREL
+ENUMX
+ BFD_RELOC_NS32K_DISP_8
+ENUMX
+ BFD_RELOC_NS32K_DISP_16
+ENUMX
+ BFD_RELOC_NS32K_DISP_32
+ENUMX
+ BFD_RELOC_NS32K_DISP_8_PCREL
+ENUMX
+ BFD_RELOC_NS32K_DISP_16_PCREL
+ENUMX
+ BFD_RELOC_NS32K_DISP_32_PCREL
+ENUMDOC
+ ns32k relocations
+
+ENUM
+ BFD_RELOC_PPC_B26
+ENUMX
+ BFD_RELOC_PPC_BA26
+ENUMX
+ BFD_RELOC_PPC_TOC16
+ENUMX
+ BFD_RELOC_PPC_B16
+ENUMX
+ BFD_RELOC_PPC_B16_BRTAKEN
+ENUMX
+ BFD_RELOC_PPC_B16_BRNTAKEN
+ENUMX
+ BFD_RELOC_PPC_BA16
+ENUMX
+ BFD_RELOC_PPC_BA16_BRTAKEN
+ENUMX
+ BFD_RELOC_PPC_BA16_BRNTAKEN
+ENUMX
+ BFD_RELOC_PPC_COPY
+ENUMX
+ BFD_RELOC_PPC_GLOB_DAT
+ENUMX
+ BFD_RELOC_PPC_JMP_SLOT
+ENUMX
+ BFD_RELOC_PPC_RELATIVE
+ENUMX
+ BFD_RELOC_PPC_LOCAL24PC
+ENUMX
+ BFD_RELOC_PPC_EMB_NADDR32
+ENUMX
+ BFD_RELOC_PPC_EMB_NADDR16
+ENUMX
+ BFD_RELOC_PPC_EMB_NADDR16_LO
+ENUMX
+ BFD_RELOC_PPC_EMB_NADDR16_HI
+ENUMX
+ BFD_RELOC_PPC_EMB_NADDR16_HA
+ENUMX
+ BFD_RELOC_PPC_EMB_SDAI16
+ENUMX
+ BFD_RELOC_PPC_EMB_SDA2I16
+ENUMX
+ BFD_RELOC_PPC_EMB_SDA2REL
+ENUMX
+ BFD_RELOC_PPC_EMB_SDA21
+ENUMX
+ BFD_RELOC_PPC_EMB_MRKREF
+ENUMX
+ BFD_RELOC_PPC_EMB_RELSEC16
+ENUMX
+ BFD_RELOC_PPC_EMB_RELST_LO
+ENUMX
+ BFD_RELOC_PPC_EMB_RELST_HI
+ENUMX
+ BFD_RELOC_PPC_EMB_RELST_HA
+ENUMX
+ BFD_RELOC_PPC_EMB_BIT_FLD
+ENUMX
+ BFD_RELOC_PPC_EMB_RELSDA
+ENUMDOC
+ Power(rs6000) and PowerPC relocations.
+
+ENUM
+ BFD_RELOC_CTOR
+ENUMDOC
+ The type of reloc used to build a contructor table - at the moment
+ probably a 32 bit wide absolute relocation, but the target can choose.
+ It generally does map to one of the other relocation types.
+
+ENUM
+ BFD_RELOC_ARM_PCREL_BRANCH
+ENUMDOC
+ ARM 26 bit pc-relative branch. The lowest two bits must be zero and are
+ not stored in the instruction.
+ENUM
+ BFD_RELOC_ARM_IMMEDIATE
+ENUMX
+ BFD_RELOC_ARM_OFFSET_IMM
+ENUMX
+ BFD_RELOC_ARM_SHIFT_IMM
+ENUMX
+ BFD_RELOC_ARM_SWI
+ENUMX
+ BFD_RELOC_ARM_MULTI
+ENUMX
+ BFD_RELOC_ARM_CP_OFF_IMM
+ENUMX
+ BFD_RELOC_ARM_ADR_IMM
+ENUMX
+ BFD_RELOC_ARM_LDR_IMM
+ENUMX
+ BFD_RELOC_ARM_LITERAL
+ENUMX
+ BFD_RELOC_ARM_IN_POOL
+ENUMX
+ BFD_RELOC_ARM_OFFSET_IMM8
+ENUMX
+ BFD_RELOC_ARM_HWLITERAL
+ENUMX
+ BFD_RELOC_ARM_THUMB_ADD
+ENUMX
+ BFD_RELOC_ARM_THUMB_IMM
+ENUMX
+ BFD_RELOC_ARM_THUMB_SHIFT
+ENUMX
+ BFD_RELOC_ARM_THUMB_OFFSET
+ENUMX
+ BFD_RELOC_ARM_GOT12
+ENUMX
+ BFD_RELOC_ARM_GOT32
+ENUMX
+ BFD_RELOC_ARM_JUMP_SLOT
+ENUMX
+ BFD_RELOC_ARM_COPY
+ENUMX
+ BFD_RELOC_ARM_GLOB_DAT
+ENUMX
+ BFD_RELOC_ARM_PLT32
+ENUMX
+ BFD_RELOC_ARM_RELATIVE
+ENUMX
+ BFD_RELOC_ARM_GOTOFF
+ENUMX
+ BFD_RELOC_ARM_GOTPC
+ENUMDOC
+ These relocs are only used within the ARM assembler. They are not
+ (at present) written to any object files.
+
+ENUM
+ BFD_RELOC_SH_PCDISP8BY2
+ENUMX
+ BFD_RELOC_SH_PCDISP12BY2
+ENUMX
+ BFD_RELOC_SH_IMM4
+ENUMX
+ BFD_RELOC_SH_IMM4BY2
+ENUMX
+ BFD_RELOC_SH_IMM4BY4
+ENUMX
+ BFD_RELOC_SH_IMM8
+ENUMX
+ BFD_RELOC_SH_IMM8BY2
+ENUMX
+ BFD_RELOC_SH_IMM8BY4
+ENUMX
+ BFD_RELOC_SH_PCRELIMM8BY2
+ENUMX
+ BFD_RELOC_SH_PCRELIMM8BY4
+ENUMX
+ BFD_RELOC_SH_SWITCH16
+ENUMX
+ BFD_RELOC_SH_SWITCH32
+ENUMX
+ BFD_RELOC_SH_USES
+ENUMX
+ BFD_RELOC_SH_COUNT
+ENUMX
+ BFD_RELOC_SH_ALIGN
+ENUMX
+ BFD_RELOC_SH_CODE
+ENUMX
+ BFD_RELOC_SH_DATA
+ENUMX
+ BFD_RELOC_SH_LABEL
+ENUMDOC
+ Hitachi SH relocs. Not all of these appear in object files.
+
+ENUM
+ BFD_RELOC_THUMB_PCREL_BRANCH9
+ENUMX
+ BFD_RELOC_THUMB_PCREL_BRANCH12
+ENUMX
+ BFD_RELOC_THUMB_PCREL_BRANCH23
+ENUMDOC
+ Thumb 23-, 12- and 9-bit pc-relative branches. The lowest bit must
+ be zero and is not stored in the instruction.
+
+ENUM
+ BFD_RELOC_ARC_B22_PCREL
+ENUMDOC
+ Argonaut RISC Core (ARC) relocs.
+ ARC 22 bit pc-relative branch. The lowest two bits must be zero and are
+ not stored in the instruction. The high 20 bits are installed in bits 26
+ through 7 of the instruction.
+ENUM
+ BFD_RELOC_ARC_B26
+ENUMDOC
+ ARC 26 bit absolute branch. The lowest two bits must be zero and are not
+ stored in the instruction. The high 24 bits are installed in bits 23
+ through 0.
+
+ENUM
+ BFD_RELOC_D10V_10_PCREL_R
+ENUMDOC
+ Mitsubishi D10V relocs.
+ This is a 10-bit reloc with the right 2 bits
+ assumed to be 0.
+ENUM
+ BFD_RELOC_D10V_10_PCREL_L
+ENUMDOC
+ Mitsubishi D10V relocs.
+ This is a 10-bit reloc with the right 2 bits
+ assumed to be 0. This is the same as the previous reloc
+ except it is in the left container, i.e.,
+ shifted left 15 bits.
+ENUM
+ BFD_RELOC_D10V_18
+ENUMDOC
+ This is an 18-bit reloc with the right 2 bits
+ assumed to be 0.
+ENUM
+ BFD_RELOC_D10V_18_PCREL
+ENUMDOC
+ This is an 18-bit reloc with the right 2 bits
+ assumed to be 0.
+
+ENUM
+ BFD_RELOC_D30V_6
+ENUMDOC
+ Mitsubishi D30V relocs.
+ This is a 6-bit absolute reloc.
+ENUM
+ BFD_RELOC_D30V_9_PCREL
+ENUMDOC
+ This is a 6-bit pc-relative reloc with
+ the right 3 bits assumed to be 0.
+ENUM
+ BFD_RELOC_D30V_9_PCREL_R
+ENUMDOC
+ This is a 6-bit pc-relative reloc with
+ the right 3 bits assumed to be 0. Same
+ as the previous reloc but on the right side
+ of the container.
+ENUM
+ BFD_RELOC_D30V_15
+ENUMDOC
+ This is a 12-bit absolute reloc with the
+ right 3 bitsassumed to be 0.
+ENUM
+ BFD_RELOC_D30V_15_PCREL
+ENUMDOC
+ This is a 12-bit pc-relative reloc with
+ the right 3 bits assumed to be 0.
+ENUM
+ BFD_RELOC_D30V_15_PCREL_R
+ENUMDOC
+ This is a 12-bit pc-relative reloc with
+ the right 3 bits assumed to be 0. Same
+ as the previous reloc but on the right side
+ of the container.
+ENUM
+ BFD_RELOC_D30V_21
+ENUMDOC
+ This is an 18-bit absolute reloc with
+ the right 3 bits assumed to be 0.
+ENUM
+ BFD_RELOC_D30V_21_PCREL
+ENUMDOC
+ This is an 18-bit pc-relative reloc with
+ the right 3 bits assumed to be 0.
+ENUM
+ BFD_RELOC_D30V_21_PCREL_R
+ENUMDOC
+ This is an 18-bit pc-relative reloc with
+ the right 3 bits assumed to be 0. Same
+ as the previous reloc but on the right side
+ of the container.
+ENUM
+ BFD_RELOC_D30V_32
+ENUMDOC
+ This is a 32-bit absolute reloc.
+ENUM
+ BFD_RELOC_D30V_32_PCREL
+ENUMDOC
+ This is a 32-bit pc-relative reloc.
+
+ENUM
+ BFD_RELOC_M32R_24
+ENUMDOC
+ Mitsubishi M32R relocs.
+ This is a 24 bit absolute address.
+ENUM
+ BFD_RELOC_M32R_10_PCREL
+ENUMDOC
+ This is a 10-bit pc-relative reloc with the right 2 bits assumed to be 0.
+ENUM
+ BFD_RELOC_M32R_18_PCREL
+ENUMDOC
+ This is an 18-bit reloc with the right 2 bits assumed to be 0.
+ENUM
+ BFD_RELOC_M32R_26_PCREL
+ENUMDOC
+ This is a 26-bit reloc with the right 2 bits assumed to be 0.
+ENUM
+ BFD_RELOC_M32R_HI16_ULO
+ENUMDOC
+ This is a 16-bit reloc containing the high 16 bits of an address
+ used when the lower 16 bits are treated as unsigned.
+ENUM
+ BFD_RELOC_M32R_HI16_SLO
+ENUMDOC
+ This is a 16-bit reloc containing the high 16 bits of an address
+ used when the lower 16 bits are treated as signed.
+ENUM
+ BFD_RELOC_M32R_LO16
+ENUMDOC
+ This is a 16-bit reloc containing the lower 16 bits of an address.
+ENUM
+ BFD_RELOC_M32R_SDA16
+ENUMDOC
+ This is a 16-bit reloc containing the small data area offset for use in
+ add3, load, and store instructions.
+
+ENUM
+ BFD_RELOC_V850_9_PCREL
+ENUMDOC
+ This is a 9-bit reloc
+ENUM
+ BFD_RELOC_V850_22_PCREL
+ENUMDOC
+ This is a 22-bit reloc
+
+ENUM
+ BFD_RELOC_V850_SDA_16_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the short data area pointer.
+ENUM
+ BFD_RELOC_V850_SDA_15_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset (of which only 15 bits are used) from the
+ short data area pointer.
+ENUM
+ BFD_RELOC_V850_ZDA_16_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the zero data area pointer.
+ENUM
+ BFD_RELOC_V850_ZDA_15_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset (of which only 15 bits are used) from the
+ zero data area pointer.
+ENUM
+ BFD_RELOC_V850_TDA_6_8_OFFSET
+ENUMDOC
+ This is an 8 bit offset (of which only 6 bits are used) from the
+ tiny data area pointer.
+ENUM
+ BFD_RELOC_V850_TDA_7_8_OFFSET
+ENUMDOC
+ This is an 8bit offset (of which only 7 bits are used) from the tiny
+ data area pointer.
+ENUM
+ BFD_RELOC_V850_TDA_7_7_OFFSET
+ENUMDOC
+ This is a 7 bit offset from the tiny data area pointer.
+ENUM
+ BFD_RELOC_V850_TDA_16_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the tiny data area pointer.
+COMMENT
+ENUM
+ BFD_RELOC_V850_TDA_4_5_OFFSET
+ENUMDOC
+ This is a 5 bit offset (of which only 4 bits are used) from the tiny
+ data area pointer.
+ENUM
+ BFD_RELOC_V850_TDA_4_4_OFFSET
+ENUMDOC
+ This is a 4 bit offset from the tiny data area pointer.
+ENUM
+ BFD_RELOC_V850_SDA_16_16_SPLIT_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the short data area pointer, with the
+ bits placed non-contigously in the instruction.
+ENUM
+ BFD_RELOC_V850_ZDA_16_16_SPLIT_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the zero data area pointer, with the
+ bits placed non-contigously in the instruction.
+ENUM
+ BFD_RELOC_V850_CALLT_6_7_OFFSET
+ENUMDOC
+ This is a 6 bit offset from the call table base pointer.
+ENUM
+ BFD_RELOC_V850_CALLT_16_16_OFFSET
+ENUMDOC
+ This is a 16 bit offset from the call table base pointer.
+COMMENT
+
+ENUM
+ BFD_RELOC_MN10300_32_PCREL
+ENUMDOC
+ This is a 32bit pcrel reloc for the mn10300, offset by two bytes in the
+ instruction.
+ENUM
+ BFD_RELOC_MN10300_16_PCREL
+ENUMDOC
+ This is a 16bit pcrel reloc for the mn10300, offset by two bytes in the
+ instruction.
+
+ENUM
+ BFD_RELOC_TIC30_LDP
+ENUMDOC
+ This is a 8bit DP reloc for the tms320c30, where the most
+ significant 8 bits of a 24 bit word are placed into the least
+ significant 8 bits of the opcode.
+
+ENUM
+ BFD_RELOC_FR30_48
+ENUMDOC
+ This is a 48 bit reloc for the FR30 that stores 32 bits.
+ENUM
+ BFD_RELOC_FR30_20
+ENUMDOC
+ This is a 32 bit reloc for the FR30 that stores 20 bits split up into
+ two sections.
+ENUM
+ BFD_RELOC_FR30_6_IN_4
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores a 6 bit word offset in
+ 4 bits.
+ENUM
+ BFD_RELOC_FR30_8_IN_8
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores an 8 bit byte offset
+ into 8 bits.
+ENUM
+ BFD_RELOC_FR30_9_IN_8
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores a 9 bit short offset
+ into 8 bits.
+ENUM
+ BFD_RELOC_FR30_10_IN_8
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores a 10 bit word offset
+ into 8 bits.
+ENUM
+ BFD_RELOC_FR30_9_PCREL
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores a 9 bit pc relative
+ short offset into 8 bits.
+ENUM
+ BFD_RELOC_FR30_12_PCREL
+ENUMDOC
+ This is a 16 bit reloc for the FR30 that stores a 12 bit pc relative
+ short offset into 11 bits.
+
+ENUM
+ BFD_RELOC_MCORE_PCREL_IMM8BY4
+ENUMX
+ BFD_RELOC_MCORE_PCREL_IMM11BY2
+ENUMX
+ BFD_RELOC_MCORE_PCREL_IMM4BY2
+ENUMX
+ BFD_RELOC_MCORE_PCREL_32
+ENUMX
+ BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2
+ENUMDOC
+ Motorola Mcore relocations.
+
+ENUM
+ BFD_RELOC_VTABLE_INHERIT
+ENUMX
+ BFD_RELOC_VTABLE_ENTRY
+ENUMDOC
+ These two relocations are used by the linker to determine which of
+ the entries in a C++ virtual function table are actually used. When
+ the --gc-sections option is given, the linker will zero out the entries
+ that are not used, so that the code for those functions need not be
+ included in the output.
+
+ VTABLE_INHERIT is a zero-space relocation used to describe to the
+ linker the inheritence tree of a C++ virtual function table. The
+ relocation's symbol should be the parent class' vtable, and the
+ relocation should be located at the child vtable.
+
+ VTABLE_ENTRY is a zero-space relocation that describes the use of a
+ virtual function table entry. The reloc's symbol should refer to the
+ table of the class mentioned in the code. Off of that base, an offset
+ describes the entry that is being used. For Rela hosts, this offset
+ is stored in the reloc's addend. For Rel hosts, we are forced to put
+ this offset in the reloc's section offset.
+
+ENDSENUM
+ BFD_RELOC_UNUSED
+CODE_FRAGMENT
+.
+.typedef enum bfd_reloc_code_real bfd_reloc_code_real_type;
+*/
+
+
+/*
+FUNCTION
+ bfd_reloc_type_lookup
+
+SYNOPSIS
+ reloc_howto_type *
+ bfd_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code);
+
+DESCRIPTION
+ Return a pointer to a howto structure which, when
+ invoked, will perform the relocation @var{code} on data from the
+ architecture noted.
+
+*/
+
+
+reloc_howto_type *
+bfd_reloc_type_lookup (abfd, code)
+ bfd *abfd;
+ bfd_reloc_code_real_type code;
+{
+ return BFD_SEND (abfd, reloc_type_lookup, (abfd, code));
+}
+
+static reloc_howto_type bfd_howto_32 =
+HOWTO (0, 00, 2, 32, false, 0, complain_overflow_bitfield, 0, "VRT32", false, 0xffffffff, 0xffffffff, true);
+
+
+/*
+INTERNAL_FUNCTION
+ bfd_default_reloc_type_lookup
+
+SYNOPSIS
+ reloc_howto_type *bfd_default_reloc_type_lookup
+ (bfd *abfd, bfd_reloc_code_real_type code);
+
+DESCRIPTION
+ Provides a default relocation lookup routine for any architecture.
+
+
+*/
+
+reloc_howto_type *
+bfd_default_reloc_type_lookup (abfd, code)
+ bfd *abfd;
+ bfd_reloc_code_real_type code;
+{
+ switch (code)
+ {
+ case BFD_RELOC_CTOR:
+ /* The type of reloc used in a ctor, which will be as wide as the
+ address - so either a 64, 32, or 16 bitter. */
+ switch (bfd_get_arch_info (abfd)->bits_per_address)
+ {
+ case 64:
+ BFD_FAIL ();
+ case 32:
+ return &bfd_howto_32;
+ case 16:
+ BFD_FAIL ();
+ default:
+ BFD_FAIL ();
+ }
+ default:
+ BFD_FAIL ();
+ }
+ return (reloc_howto_type *) NULL;
+}
+
+/*
+FUNCTION
+ bfd_get_reloc_code_name
+
+SYNOPSIS
+ const char *bfd_get_reloc_code_name (bfd_reloc_code_real_type code);
+
+DESCRIPTION
+ Provides a printable name for the supplied relocation code.
+ Useful mainly for printing error messages.
+*/
+
+const char *
+bfd_get_reloc_code_name (code)
+ bfd_reloc_code_real_type code;
+{
+ if (code > BFD_RELOC_UNUSED)
+ return 0;
+ return bfd_reloc_code_real_names[(int)code];
+}
+
+/*
+INTERNAL_FUNCTION
+ bfd_generic_relax_section
+
+SYNOPSIS
+ boolean bfd_generic_relax_section
+ (bfd *abfd,
+ asection *section,
+ struct bfd_link_info *,
+ boolean *);
+
+DESCRIPTION
+ Provides default handling for relaxing for back ends which
+ don't do relaxing -- i.e., does nothing.
+*/
+
+/*ARGSUSED*/
+boolean
+bfd_generic_relax_section (abfd, section, link_info, again)
+ bfd *abfd;
+ asection *section;
+ struct bfd_link_info *link_info;
+ boolean *again;
+{
+ *again = false;
+ return true;
+}
+
+/*
+INTERNAL_FUNCTION
+ bfd_generic_gc_sections
+
+SYNOPSIS
+ boolean bfd_generic_gc_sections
+ (bfd *, struct bfd_link_info *);
+
+DESCRIPTION
+ Provides default handling for relaxing for back ends which
+ don't do section gc -- i.e., does nothing.
+*/
+
+/*ARGSUSED*/
+boolean
+bfd_generic_gc_sections (abfd, link_info)
+ bfd *abfd;
+ struct bfd_link_info *link_info;
+{
+ return true;
+}
+
+/*
+INTERNAL_FUNCTION
+ bfd_generic_get_relocated_section_contents
+
+SYNOPSIS
+ bfd_byte *
+ bfd_generic_get_relocated_section_contents (bfd *abfd,
+ struct bfd_link_info *link_info,
+ struct bfd_link_order *link_order,
+ bfd_byte *data,
+ boolean relocateable,
+ asymbol **symbols);
+
+DESCRIPTION
+ Provides default handling of relocation effort for back ends
+ which can't be bothered to do it efficiently.
+
+*/
+
+bfd_byte *
+bfd_generic_get_relocated_section_contents (abfd, link_info, link_order, data,
+ relocateable, symbols)
+ bfd *abfd;
+ struct bfd_link_info *link_info;
+ struct bfd_link_order *link_order;
+ bfd_byte *data;
+ boolean relocateable;
+ asymbol **symbols;
+{
+ /* Get enough memory to hold the stuff */
+ bfd *input_bfd = link_order->u.indirect.section->owner;
+ asection *input_section = link_order->u.indirect.section;
+
+ long reloc_size = bfd_get_reloc_upper_bound (input_bfd, input_section);
+ arelent **reloc_vector = NULL;
+ long reloc_count;
+
+ if (reloc_size < 0)
+ goto error_return;
+
+ reloc_vector = (arelent **) bfd_malloc ((size_t) reloc_size);
+ if (reloc_vector == NULL && reloc_size != 0)
+ goto error_return;
+
+ /* read in the section */
+ if (!bfd_get_section_contents (input_bfd,
+ input_section,
+ (PTR) data,
+ 0,
+ input_section->_raw_size))
+ goto error_return;
+
+ /* We're not relaxing the section, so just copy the size info */
+ input_section->_cooked_size = input_section->_raw_size;
+ input_section->reloc_done = true;
+
+ reloc_count = bfd_canonicalize_reloc (input_bfd,
+ input_section,
+ reloc_vector,
+ symbols);
+ if (reloc_count < 0)
+ goto error_return;
+
+ if (reloc_count > 0)
+ {
+ arelent **parent;
+ for (parent = reloc_vector; *parent != (arelent *) NULL;
+ parent++)
+ {
+ char *error_message = (char *) NULL;
+ bfd_reloc_status_type r =
+ bfd_perform_relocation (input_bfd,
+ *parent,
+ (PTR) data,
+ input_section,
+ relocateable ? abfd : (bfd *) NULL,
+ &error_message);
+
+ if (relocateable)
+ {
+ asection *os = input_section->output_section;
+
+ /* A partial link, so keep the relocs */
+ os->orelocation[os->reloc_count] = *parent;
+ os->reloc_count++;
+ }
+
+ if (r != bfd_reloc_ok)
+ {
+ switch (r)
+ {
+ case bfd_reloc_undefined:
+ if (!((*link_info->callbacks->undefined_symbol)
+ (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
+ input_bfd, input_section, (*parent)->address)))
+ goto error_return;
+ break;
+ case bfd_reloc_dangerous:
+ BFD_ASSERT (error_message != (char *) NULL);
+ if (!((*link_info->callbacks->reloc_dangerous)
+ (link_info, error_message, input_bfd, input_section,
+ (*parent)->address)))
+ goto error_return;
+ break;
+ case bfd_reloc_overflow:
+ if (!((*link_info->callbacks->reloc_overflow)
+ (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
+ (*parent)->howto->name, (*parent)->addend,
+ input_bfd, input_section, (*parent)->address)))
+ goto error_return;
+ break;
+ case bfd_reloc_outofrange:
+ default:
+ abort ();
+ break;
+ }
+
+ }
+ }
+ }
+ if (reloc_vector != NULL)
+ free (reloc_vector);
+ return data;
+
+error_return:
+ if (reloc_vector != NULL)
+ free (reloc_vector);
+ return NULL;
+}