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/* BFD back-end for Intel 386 COFF files.
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Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
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2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
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Free Software Foundation, Inc.
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Written by Cygnus Support.
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "coff/i386.h"
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#include "coff/internal.h"
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#include "coff/go32exe.h"
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#ifndef bfd_pe_print_pdata
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#define bfd_pe_print_pdata NULL
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static reloc_howto_type *coff_i386_rtype_to_howto
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(bfd *, asection *, struct internal_reloc *,
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struct coff_link_hash_entry *, struct internal_syment *,
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static reloc_howto_type *coff_i386_reloc_type_lookup
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(bfd *, bfd_reloc_code_real_type);
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#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)
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/* The page size is a guess based on ELF. */
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#define COFF_PAGE_SIZE 0x1000
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/* For some reason when using i386 COFF the value stored in the .text
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section for a reference to a common symbol is the value itself plus
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any desired offset. Ian Taylor, Cygnus Support. */
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/* If we are producing relocatable output, we need to do some
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adjustments to the object file that are not done by the
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bfd_perform_relocation function. This function is called by every
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reloc type to make any required adjustments. */
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static bfd_reloc_status_type
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coff_i386_reloc (bfd *abfd,
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asection *input_section ATTRIBUTE_UNUSED,
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char **error_message ATTRIBUTE_UNUSED)
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if (output_bfd == (bfd *) NULL)
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return bfd_reloc_continue;
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if (bfd_is_com_section (symbol->section))
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/* We are relocating a common symbol. The current value in the
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object file is ORIG + OFFSET, where ORIG is the value of the
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common symbol as seen by the object file when it was compiled
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(this may be zero if the symbol was undefined) and OFFSET is
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the offset into the common symbol (normally zero, but may be
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non-zero when referring to a field in a common structure).
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ORIG is the negative of reloc_entry->addend, which is set by
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the CALC_ADDEND macro below. We want to replace the value in
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the object file with NEW + OFFSET, where NEW is the value of
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the common symbol which we are going to put in the final
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object file. NEW is symbol->value. */
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diff = symbol->value + reloc_entry->addend;
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/* In PE mode, we do not offset the common symbol. */
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diff = reloc_entry->addend;
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/* For some reason bfd_perform_relocation always effectively
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ignores the addend for a COFF target when producing
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relocatable output. This seems to be always wrong for 386
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COFF, so we handle the addend here instead. */
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if (output_bfd == (bfd *) NULL)
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reloc_howto_type *howto = reloc_entry->howto;
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/* Although PC relative relocations are very similar between
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PE and non-PE formats, but they are off by 1 << howto->size
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bytes. For the external relocation, PE is very different
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from others. See md_apply_fix3 () in gas/config/tc-i386.c.
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When we link PE and non-PE object files together to
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generate a non-PE executable, we have to compensate it
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if (howto->pc_relative && howto->pcrel_offset)
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diff = -(1 << howto->size);
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else if (symbol->flags & BSF_WEAK)
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diff = reloc_entry->addend - symbol->value;
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diff = -reloc_entry->addend;
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diff = reloc_entry->addend;
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/* FIXME: How should this case be handled? */
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if (reloc_entry->howto->type == R_IMAGEBASE
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&& output_bfd != NULL
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&& bfd_get_flavour(output_bfd) == bfd_target_coff_flavour)
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diff -= pe_data (output_bfd)->pe_opthdr.ImageBase;
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x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask))
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reloc_howto_type *howto = reloc_entry->howto;
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unsigned char *addr = (unsigned char *) data + reloc_entry->address;
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char x = bfd_get_8 (abfd, addr);
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bfd_put_8 (abfd, x, addr);
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short x = bfd_get_16 (abfd, addr);
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bfd_put_16 (abfd, (bfd_vma) x, addr);
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long x = bfd_get_32 (abfd, addr);
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bfd_put_32 (abfd, (bfd_vma) x, addr);
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/* Now let bfd_perform_relocation finish everything up. */
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return bfd_reloc_continue;
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/* Return TRUE if this relocation should appear in the output .reloc
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static bfd_boolean in_reloc_p (bfd * abfd ATTRIBUTE_UNUSED,
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reloc_howto_type *howto)
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return ! howto->pc_relative && howto->type != R_IMAGEBASE
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&& howto->type != R_SECREL32;
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#endif /* COFF_WITH_PE */
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#define PCRELOFFSET FALSE
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static reloc_howto_type howto_table[] =
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HOWTO (R_DIR32, /* type */
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2, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0xffffffff, /* src_mask */
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0xffffffff, /* dst_mask */
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TRUE), /* pcrel_offset */
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/* PE IMAGE_REL_I386_DIR32NB relocation (7). */
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HOWTO (R_IMAGEBASE, /* type */
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2, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0xffffffff, /* src_mask */
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0xffffffff, /* dst_mask */
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FALSE), /* pcrel_offset */
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/* 32-bit longword section relative relocation (013). */
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HOWTO (R_SECREL32, /* type */
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2, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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"secrel32", /* name */
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TRUE, /* partial_inplace */
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0xffffffff, /* src_mask */
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0xffffffff, /* dst_mask */
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TRUE), /* pcrel_offset */
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/* Byte relocation (017). */
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HOWTO (R_RELBYTE, /* type */
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0, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0x000000ff, /* src_mask */
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0x000000ff, /* dst_mask */
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PCRELOFFSET), /* pcrel_offset */
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/* 16-bit word relocation (020). */
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HOWTO (R_RELWORD, /* type */
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1, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0x0000ffff, /* src_mask */
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0x0000ffff, /* dst_mask */
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PCRELOFFSET), /* pcrel_offset */
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/* 32-bit longword relocation (021). */
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HOWTO (R_RELLONG, /* type */
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2, /* size (0 = byte, 1 = short, 2 = long) */
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FALSE, /* pc_relative */
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complain_overflow_bitfield, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0xffffffff, /* src_mask */
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0xffffffff, /* dst_mask */
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PCRELOFFSET), /* pcrel_offset */
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/* Byte PC relative relocation (022). */
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HOWTO (R_PCRBYTE, /* type */
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0, /* size (0 = byte, 1 = short, 2 = long) */
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TRUE, /* pc_relative */
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complain_overflow_signed, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0x000000ff, /* src_mask */
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0x000000ff, /* dst_mask */
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PCRELOFFSET), /* pcrel_offset */
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/* 16-bit word PC relative relocation (023). */
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HOWTO (R_PCRWORD, /* type */
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1, /* size (0 = byte, 1 = short, 2 = long) */
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TRUE, /* pc_relative */
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complain_overflow_signed, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0x0000ffff, /* src_mask */
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0x0000ffff, /* dst_mask */
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PCRELOFFSET), /* pcrel_offset */
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/* 32-bit longword PC relative relocation (024). */
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HOWTO (R_PCRLONG, /* type */
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2, /* size (0 = byte, 1 = short, 2 = long) */
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TRUE, /* pc_relative */
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complain_overflow_signed, /* complain_on_overflow */
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coff_i386_reloc, /* special_function */
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TRUE, /* partial_inplace */
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0xffffffff, /* src_mask */
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0xffffffff, /* dst_mask */
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PCRELOFFSET) /* pcrel_offset */
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/* Turn a howto into a reloc nunmber */
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#define SELECT_RELOC(x,howto) { x.r_type = howto->type; }
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#define BADMAG(x) I386BADMAG(x)
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#define I386 1 /* Customize coffcode.h */
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#define RTYPE2HOWTO(cache_ptr, dst) \
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((cache_ptr)->howto = \
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((dst)->r_type < sizeof (howto_table) / sizeof (howto_table[0]) \
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? howto_table + (dst)->r_type \
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/* For 386 COFF a STYP_NOLOAD | STYP_BSS section is part of a shared
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library. On some other COFF targets STYP_BSS is normally
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#define BSS_NOLOAD_IS_SHARED_LIBRARY
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/* Compute the addend of a reloc. If the reloc is to a common symbol,
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the object file contains the value of the common symbol. By the
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time this is called, the linker may be using a different symbol
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from a different object file with a different value. Therefore, we
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hack wildly to locate the original symbol from this file so that we
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can make the correct adjustment. This macro sets coffsym to the
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symbol from the original file, and uses it to set the addend value
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correctly. If this is not a common symbol, the usual addend
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calculation is done, except that an additional tweak is needed for
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FIXME: This macro refers to symbols and asect; these are from the
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calling function, not the macro arguments. */
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#define CALC_ADDEND(abfd, ptr, reloc, cache_ptr) \
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coff_symbol_type *coffsym = (coff_symbol_type *) NULL; \
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if (ptr && bfd_asymbol_bfd (ptr) != abfd) \
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coffsym = (obj_symbols (abfd) \
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+ (cache_ptr->sym_ptr_ptr - symbols)); \
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coffsym = coff_symbol_from (abfd, ptr); \
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if (coffsym != (coff_symbol_type *) NULL \
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&& coffsym->native->u.syment.n_scnum == 0) \
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cache_ptr->addend = - coffsym->native->u.syment.n_value; \
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else if (ptr && bfd_asymbol_bfd (ptr) == abfd \
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&& ptr->section != (asection *) NULL) \
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cache_ptr->addend = - (ptr->section->vma + ptr->value); \
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cache_ptr->addend = 0; \
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if (ptr && howto_table[reloc.r_type].pc_relative) \
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cache_ptr->addend += asect->vma; \
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/* We use the special COFF backend linker. For normal i386 COFF, we
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can use the generic relocate_section routine. For PE, we need our
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#define coff_relocate_section _bfd_coff_generic_relocate_section
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#else /* COFF_WITH_PE */
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/* The PE relocate section routine. The only difference between this
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and the regular routine is that we don't want to do anything for a
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coff_pe_i386_relocate_section (bfd *output_bfd,
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struct bfd_link_info *info,
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asection *input_section,
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struct internal_reloc *relocs,
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struct internal_syment *syms,
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if (info->relocatable)
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return _bfd_coff_generic_relocate_section (output_bfd, info, input_bfd,
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input_section, contents,
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relocs, syms, sections);
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#define coff_relocate_section coff_pe_i386_relocate_section
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#endif /* COFF_WITH_PE */
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/* Convert an rtype to howto for the COFF backend linker. */
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static reloc_howto_type *
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coff_i386_rtype_to_howto (bfd *abfd ATTRIBUTE_UNUSED,
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struct internal_reloc *rel,
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struct coff_link_hash_entry *h,
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struct internal_syment *sym,
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reloc_howto_type *howto;
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if (rel->r_type >= sizeof (howto_table) / sizeof (howto_table[0]))
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bfd_set_error (bfd_error_bad_value);
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howto = howto_table + rel->r_type;
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/* Cancel out code in _bfd_coff_generic_relocate_section. */
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if (howto->pc_relative)
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*addendp += sec->vma;
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if (sym != NULL && sym->n_scnum == 0 && sym->n_value != 0)
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/* This is a common symbol. The section contents include the
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size (sym->n_value) as an addend. The relocate_section
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function will be adding in the final value of the symbol. We
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need to subtract out the current size in order to get the
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BFD_ASSERT (h != NULL);
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/* I think we *do* want to bypass this. If we don't, I have
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seen some data parameters get the wrong relocation address.
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If I link two versions with and without this section bypassed
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and then do a binary comparison, the addresses which are
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different can be looked up in the map. The case in which
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this section has been bypassed has addresses which correspond
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to values I can find in the map. */
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*addendp -= sym->n_value;
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/* If the output symbol is common (in which case this must be a
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relocatable link), we need to add in the final size of the
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if (h != NULL && h->root.type == bfd_link_hash_common)
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*addendp += h->root.u.c.size;
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if (howto->pc_relative)
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/* If the symbol is defined, then the generic code is going to
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add back the symbol value in order to cancel out an
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adjustment it made to the addend. However, we set the addend
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to 0 at the start of this function. We need to adjust here,
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to avoid the adjustment the generic code will make. FIXME:
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This is getting a bit hackish. */
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if (sym != NULL && sym->n_scnum != 0)
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*addendp -= sym->n_value;
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if (rel->r_type == R_IMAGEBASE
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&& (bfd_get_flavour(sec->output_section->owner)
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== bfd_target_coff_flavour))
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*addendp -= pe_data(sec->output_section->owner)->pe_opthdr.ImageBase;
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BFD_ASSERT (sym != NULL);
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if (rel->r_type == R_SECREL32 && sym != NULL)
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if (h && (h->root.type == bfd_link_hash_defined
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|| h->root.type == bfd_link_hash_defweak))
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osect_vma = h->root.u.def.section->output_section->vma;
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/* Sigh, the only way to get the section to offset against
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is to find it the hard way. */
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for (s = abfd->sections, i = 1; i < sym->n_scnum; i++)
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osect_vma = s->output_section->vma;
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*addendp -= osect_vma;
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#define coff_bfd_reloc_type_lookup coff_i386_reloc_type_lookup
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#define coff_bfd_reloc_name_lookup coff_i386_reloc_name_lookup
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static reloc_howto_type *
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coff_i386_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
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bfd_reloc_code_real_type code)
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return howto_table + R_IMAGEBASE;
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return howto_table + R_DIR32;
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case BFD_RELOC_32_PCREL:
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return howto_table + R_PCRLONG;
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return howto_table + R_RELWORD;
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case BFD_RELOC_16_PCREL:
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return howto_table + R_PCRWORD;
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return howto_table + R_RELBYTE;
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case BFD_RELOC_8_PCREL:
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return howto_table + R_PCRBYTE;
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case BFD_RELOC_32_SECREL:
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return howto_table + R_SECREL32;
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static reloc_howto_type *
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coff_i386_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
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for (i = 0; i < sizeof (howto_table) / sizeof (howto_table[0]); i++)
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if (howto_table[i].name != NULL
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&& strcasecmp (howto_table[i].name, r_name) == 0)
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return &howto_table[i];
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#define coff_rtype_to_howto coff_i386_rtype_to_howto
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#ifdef TARGET_UNDERSCORE
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/* If i386 gcc uses underscores for symbol names, then it does not use
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a leading dot for local labels, so if TARGET_UNDERSCORE is defined
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we treat all symbols starting with L as local. */
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coff_i386_is_local_label_name (bfd *abfd, const char *name)
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return _bfd_coff_is_local_label_name (abfd, name);
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#define coff_bfd_is_local_label_name coff_i386_is_local_label_name
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#endif /* TARGET_UNDERSCORE */
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#include "coffcode.h"
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#define _bfd_generic_find_nearest_line_discriminator \
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coff_find_nearest_line_discriminator
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"coff-i386", /* name */
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bfd_target_coff_flavour,
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BFD_ENDIAN_LITTLE, /* data byte order is little */
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BFD_ENDIAN_LITTLE, /* header byte order is little */
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(HAS_RELOC | EXEC_P | /* object flags */
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HAS_LINENO | HAS_DEBUG |
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HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED | BFD_COMPRESS | BFD_DECOMPRESS ),
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(SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
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| SEC_LINK_ONCE | SEC_LINK_DUPLICATES | SEC_READONLY | SEC_DEBUGGING
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| SEC_CODE | SEC_DATA | SEC_EXCLUDE ),
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#ifdef TARGET_UNDERSCORE
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TARGET_UNDERSCORE, /* leading underscore */
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0, /* leading underscore */
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'/', /* ar_pad_char */
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15, /* ar_max_namelen */
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0, /* match priority. */
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bfd_getl64, bfd_getl_signed_64, bfd_putl64,
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bfd_getl32, bfd_getl_signed_32, bfd_putl32,
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bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
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bfd_getl64, bfd_getl_signed_64, bfd_putl64,
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bfd_getl32, bfd_getl_signed_32, bfd_putl32,
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bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
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/* Note that we allow an object file to be treated as a core file as well. */
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/* bfd_check_format */
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#ifdef COFF_CHECK_FORMAT
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{_bfd_dummy_target, COFF_CHECK_FORMAT,
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bfd_generic_archive_p, COFF_CHECK_FORMAT},
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{_bfd_dummy_target, coff_object_p, bfd_generic_archive_p, coff_object_p},
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{bfd_false, coff_mkobject, _bfd_generic_mkarchive, /* bfd_set_format */
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{bfd_false, coff_write_object_contents, /* bfd_write_contents */
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_bfd_write_archive_contents, bfd_false},
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BFD_JUMP_TABLE_GENERIC (coff),
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BFD_JUMP_TABLE_COPY (coff),
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BFD_JUMP_TABLE_CORE (_bfd_nocore),
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BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
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BFD_JUMP_TABLE_SYMBOLS (coff),
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BFD_JUMP_TABLE_RELOCS (coff),
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BFD_JUMP_TABLE_WRITE (coff),
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BFD_JUMP_TABLE_LINK (coff),
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BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),