-/* This is the relocation function for the RS/6000/POWER/PowerPC.
- This is currently the only processor which uses XCOFF; I hope that
- will never change. */
-
-boolean
-_bfd_ppc_xcoff_relocate_section (output_bfd, info, input_bfd,
- input_section, contents, relocs, syms,
- sections)
- bfd *output_bfd;
- struct bfd_link_info *info;
- bfd *input_bfd;
- asection *input_section;
- bfd_byte *contents;
- struct internal_reloc *relocs;
- struct internal_syment *syms;
- asection **sections;
-{
- struct internal_reloc *rel;
- struct internal_reloc *relend;
-
- rel = relocs;
- relend = rel + input_section->reloc_count;
- for (; rel < relend; rel++)
- {
- long symndx;
- struct xcoff_link_hash_entry *h;
- struct internal_syment *sym;
- bfd_vma addend;
- bfd_vma val;
- struct reloc_howto_struct howto;
- bfd_reloc_status_type rstat;
-
- /* Relocation type R_REF is a special relocation type which is
- merely used to prevent garbage collection from occurring for
- the csect including the symbol which it references. */
- if (rel->r_type == R_REF)
- continue;
-
- symndx = rel->r_symndx;
-
- if (symndx == -1)
- {
- h = NULL;
- sym = NULL;
- addend = 0;
- }
- else
- {
- h = obj_xcoff_sym_hashes (input_bfd)[symndx];
- sym = syms + symndx;
- addend = - sym->n_value;
- }
-
- /* We build the howto information on the fly. */
-
- howto.type = rel->r_type;
- howto.rightshift = 0;
- howto.size = 2;
- howto.bitsize = (rel->r_size & 0x1f) + 1;
- howto.pc_relative = false;
- howto.bitpos = 0;
- if ((rel->r_size & 0x80) != 0)
- howto.complain_on_overflow = complain_overflow_signed;
- else
- howto.complain_on_overflow = complain_overflow_bitfield;
- howto.special_function = NULL;
- howto.name = "internal";
- howto.partial_inplace = true;
- if (howto.bitsize == 32)
- howto.src_mask = howto.dst_mask = 0xffffffff;
- else
- {
- howto.src_mask = howto.dst_mask = (1 << howto.bitsize) - 1;
- if (howto.bitsize == 16)
- howto.size = 1;
- }
- howto.pcrel_offset = false;
-
- val = 0;
-
- if (h == NULL)
- {
- asection *sec;
-
- if (symndx == -1)
- {
- sec = bfd_abs_section_ptr;
- val = 0;
- }
- else
- {
- sec = sections[symndx];
- /* Hack to make sure we use the right TOC anchor value
- if this reloc is against the TOC anchor. */
- if (sec->name[3] == '0'
- && strcmp (sec->name, ".tc0") == 0)
- val = xcoff_data (output_bfd)->toc;
- else
- val = (sec->output_section->vma
- + sec->output_offset
- + sym->n_value
- - sec->vma);
- }
- }
- else
- {
- if (h->root.type == bfd_link_hash_defined
- || h->root.type == bfd_link_hash_defweak)
- {
- asection *sec;
-
- sec = h->root.u.def.section;
- val = (h->root.u.def.value
- + sec->output_section->vma
- + sec->output_offset);
- }
- else if (h->root.type == bfd_link_hash_common)
- {
- asection *sec;
-
- sec = h->root.u.c.p->section;
- val = (sec->output_section->vma
- + sec->output_offset);
- }
- else if ((h->flags & XCOFF_DEF_DYNAMIC) != 0
- || (h->flags & XCOFF_IMPORT) != 0)
- {
- /* Every symbol in a shared object is defined somewhere. */
- val = 0;
- }
- else if (! info->relocateable
- && ! info->shared)
- {
- if (! ((*info->callbacks->undefined_symbol)
- (info, h->root.root.string, input_bfd, input_section,
- rel->r_vaddr - input_section->vma)))
- return false;
- }
- }
-
- /* I took the relocation type definitions from two documents:
- the PowerPC AIX Version 4 Application Binary Interface, First
- Edition (April 1992), and the PowerOpen ABI, Big-Endian
- 32-Bit Hardware Implementation (June 30, 1994). Differences
- between the documents are noted below. */
-
- switch (rel->r_type)
- {
- case R_RTB:
- case R_RRTBI:
- case R_RRTBA:
- /* These relocs are defined by the PowerPC ABI to be
- relative branches which use half of the difference
- between the symbol and the program counter. I can't
- quite figure out when this is useful. These relocs are
- not defined by the PowerOpen ABI. */
- default:
- (*_bfd_error_handler)
- ("%s: unsupported relocation type 0x%02x",
- bfd_get_filename (input_bfd), (unsigned int) rel->r_type);
- bfd_set_error (bfd_error_bad_value);
- return false;
- case R_POS:
- /* Simple positive relocation. */
- break;
- case R_NEG:
- /* Simple negative relocation. */
- val = - val;
- break;
- case R_REL:
- /* Simple PC relative relocation. */
- howto.pc_relative = true;
- break;
- case R_TOC:
- /* TOC relative relocation. The value in the instruction in
- the input file is the offset from the input file TOC to
- the desired location. We want the offset from the final
- TOC to the desired location. We have:
- isym = iTOC + in
- iinsn = in + o
- osym = oTOC + on
- oinsn = on + o
- so we must change insn by on - in.
- */
- case R_GL:
- /* Global linkage relocation. The value of this relocation
- is the address of the entry in the TOC section. */
- case R_TCL:
- /* Local object TOC address. I can't figure out the
- difference between this and case R_GL. */
- case R_TRL:
- /* TOC relative relocation. A TOC relative load instruction
- which may be changed to a load address instruction.
- FIXME: We don't currently implement this optimization. */
- case R_TRLA:
- /* TOC relative relocation. This is a TOC relative load
- address instruction which may be changed to a load
- instruction. FIXME: I don't know if this is the correct
- implementation. */
- if (h != NULL && h->toc_section == NULL)
- {
- (*_bfd_error_handler)
- ("%s: TOC reloc at 0x%x to symbol `%s' with no TOC entry",
- bfd_get_filename (input_bfd), rel->r_vaddr,
- h->root.root.string);
- bfd_set_error (bfd_error_bad_value);
- return false;
- }
- if (h != NULL)
- {
- BFD_ASSERT ((h->flags & XCOFF_SET_TOC) == 0);
- val = (h->toc_section->output_section->vma
- + h->toc_section->output_offset);
- }
- val = ((val - xcoff_data (output_bfd)->toc)
- - (sym->n_value - xcoff_data (input_bfd)->toc));
- addend = 0;
- break;
- case R_BA:
- /* Absolute branch. We don't want to mess with the lower
- two bits of the instruction. */
- case R_CAI:
- /* The PowerPC ABI defines this as an absolute call which
- may be modified to become a relative call. The PowerOpen
- ABI does not define this relocation type. */
- case R_RBA:
- /* Absolute branch which may be modified to become a
- relative branch. */
- case R_RBAC:
- /* The PowerPC ABI defines this as an absolute branch to a
- fixed address which may be modified to an absolute branch
- to a symbol. The PowerOpen ABI does not define this
- relocation type. */
- case R_RBRC:
- /* The PowerPC ABI defines this as an absolute branch to a
- fixed address which may be modified to a relative branch.
- The PowerOpen ABI does not define this relocation type. */
- howto.src_mask &= ~3;
- howto.dst_mask = howto.src_mask;
- break;
- case R_BR:
- /* Relative branch. We don't want to mess with the lower
- two bits of the instruction. */
- case R_CREL:
- /* The PowerPC ABI defines this as a relative call which may
- be modified to become an absolute call. The PowerOpen
- ABI does not define this relocation type. */
- case R_RBR:
- /* A relative branch which may be modified to become an
- absolute branch. FIXME: We don't implement this,
- although we should for symbols of storage mapping class
- XMC_XO. */
- howto.pc_relative = true;
- howto.src_mask &= ~3;
- howto.dst_mask = howto.src_mask;
- break;
- case R_RL:
- /* The PowerPC AIX ABI describes this as a load which may be
- changed to a load address. The PowerOpen ABI says this
- is the same as case R_POS. */
- break;
- case R_RLA:
- /* The PowerPC AIX ABI describes this as a load address
- which may be changed to a load. The PowerOpen ABI says
- this is the same as R_POS. */
- break;
- }
-
- /* If we see an R_BR or R_RBR reloc which is jumping to global
- linkage code, and it is followed by an appropriate cror nop
- instruction, we replace the cror with lwz r2,20(r1). This
- restores the TOC after the glink code. Contrariwise, if the
- call is followed by a lwz r2,20(r1), but the call is not
- going to global linkage code, we can replace the load with a
- cror. */
- if ((rel->r_type == R_BR || rel->r_type == R_RBR)
- && h != NULL
- && h->root.type == bfd_link_hash_defined
- && (rel->r_vaddr - input_section->vma + 8
- <= input_section->_cooked_size))
- {
- bfd_byte *pnext;
- unsigned long next;
-
- pnext = contents + (rel->r_vaddr - input_section->vma) + 4;
- next = bfd_get_32 (input_bfd, pnext);
- if (h->smclas == XMC_GL)
- {
- if (next == 0x4def7b82 /* cror 15,15,15 */
- || next == 0x4ffffb82) /* cror 31,31,31 */
- bfd_put_32 (input_bfd, 0x80410014, pnext); /* lwz r1,20(r1) */
- }
- else
- {
- if (next == 0x80410014) /* lwz r1,20(r1) */
- bfd_put_32 (input_bfd, 0x4ffffb82, pnext); /* cror 31,31,31 */
- }
- }
-
- /* A PC relative reloc includes the section address. */
- if (howto.pc_relative)
- addend += input_section->vma;