bfd/coff-go32.c

   1 /* BFD back-end for Intel 386 COFF files (DJGPP variant).
   2    Copyright (C) 1990-2024 Free Software Foundation, Inc.
   3    Written by DJ Delorie.
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22 #define TARGET_SYM              i386_coff_go32_vec
  23 #define TARGET_NAME             "coff-go32"
  24 #define TARGET_UNDERSCORE       '_'
  25 #define COFF_GO32
  26 #define COFF_LONG_SECTION_NAMES
  27 #define COFF_SUPPORT_GNU_LINKONCE
  28 #define COFF_LONG_FILENAMES
  29
  30 #define COFF_SECTION_ALIGNMENT_ENTRIES \
  31 { COFF_SECTION_NAME_PARTIAL_MATCH (".data"), \
  32   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  33 { COFF_SECTION_NAME_PARTIAL_MATCH (".text"), \
  34   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  35 { COFF_SECTION_NAME_PARTIAL_MATCH (".const"), \
  36   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  37 { COFF_SECTION_NAME_PARTIAL_MATCH (".rodata"), \
  38   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  39 { COFF_SECTION_NAME_PARTIAL_MATCH (".bss"), \
  40   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  41 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.d"), \
  42   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  43 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.t"), \
  44   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  45 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.r"), \
  46   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  47 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.b"), \
  48   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
  49 { COFF_SECTION_NAME_PARTIAL_MATCH (".debug"), \
  50   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }, \
  51 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.wi"), \
  52   COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }
  53
  54 /* Section contains extended relocations. */
  55 #define IMAGE_SCN_LNK_NRELOC_OVFL (0x01000000)
  56
  57 #include "sysdep.h"
  58 #include "bfd.h"
  59
  60 /* The following functions are not static, because they are also
  61    used for coff-go32-exe (coff-stgo32.c).  */
  62 bool _bfd_go32_mkobject (bfd *);
  63 void _bfd_go32_swap_scnhdr_in (bfd *, void *, void *);
  64 unsigned int _bfd_go32_swap_scnhdr_out (bfd *, void *, void *);
  65
  66 #define coff_mkobject _bfd_go32_mkobject
  67 #define coff_SWAP_scnhdr_in _bfd_go32_swap_scnhdr_in
  68 #define coff_SWAP_scnhdr_out _bfd_go32_swap_scnhdr_out
  69
  70 #include "coff-i386.c"
  71
  72 bool
  73 _bfd_go32_mkobject (bfd * abfd)
  74 {
  75   const bfd_size_type amt = sizeof (coff_data_type);
  76
  77   abfd->tdata.coff_obj_data = bfd_zalloc (abfd, amt);
  78   if (abfd->tdata.coff_obj_data == NULL)
  79     return false;
  80
  81   coff_data (abfd)->go32 = true;
  82
  83   bfd_coff_long_section_names (abfd)
  84     = coff_backend_info (abfd)->_bfd_coff_long_section_names;
  85
  86   return true;
  87 }
  88
  89 void
  90 _bfd_go32_swap_scnhdr_in (bfd * abfd, void * ext, void * in)
  91 {
  92   SCNHDR *scnhdr_ext = (SCNHDR *) ext;
  93   struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
  94
  95   memcpy (scnhdr_int->s_name, scnhdr_ext->s_name, sizeof (scnhdr_int->s_name));
  96
  97   scnhdr_int->s_vaddr = GET_SCNHDR_VADDR (abfd, scnhdr_ext->s_vaddr);
  98   scnhdr_int->s_paddr = GET_SCNHDR_PADDR (abfd, scnhdr_ext->s_paddr);
  99   scnhdr_int->s_size = GET_SCNHDR_SIZE (abfd, scnhdr_ext->s_size);
 100
 101   scnhdr_int->s_scnptr = GET_SCNHDR_SCNPTR (abfd, scnhdr_ext->s_scnptr);
 102   scnhdr_int->s_relptr = GET_SCNHDR_RELPTR (abfd, scnhdr_ext->s_relptr);
 103   scnhdr_int->s_lnnoptr = GET_SCNHDR_LNNOPTR (abfd, scnhdr_ext->s_lnnoptr);
 104   scnhdr_int->s_flags = GET_SCNHDR_FLAGS (abfd, scnhdr_ext->s_flags);
 105   scnhdr_int->s_nreloc = GET_SCNHDR_NRELOC (abfd, scnhdr_ext->s_nreloc);
 106   scnhdr_int->s_nlnno = GET_SCNHDR_NLNNO (abfd, scnhdr_ext->s_nlnno);
 107
 108   /* DJGPP follows the same strategy as PE COFF.
 109      Iff the file is an executable then the higher 16 bits
 110      of the line number have been stored in the relocation
 111      counter field.  */
 112   if (abfd->flags & EXEC_P && (strcmp (scnhdr_ext->s_name, ".text") == 0))
 113     {
 114       scnhdr_int->s_nlnno
 115         = (GET_SCNHDR_NRELOC (abfd, scnhdr_ext->s_nreloc) << 16)
 116           + GET_SCNHDR_NLNNO (abfd, scnhdr_ext->s_nlnno);
 117       scnhdr_int->s_nreloc = 0;
 118     }
 119 }
 120
 121 unsigned int
 122 _bfd_go32_swap_scnhdr_out (bfd * abfd, void * in, void * out)
 123 {
 124   struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
 125   SCNHDR *scnhdr_ext = (SCNHDR *) out;
 126   unsigned int ret = bfd_coff_scnhsz (abfd);
 127
 128   memcpy (scnhdr_ext->s_name, scnhdr_int->s_name, sizeof (scnhdr_int->s_name));
 129
 130   PUT_SCNHDR_VADDR (abfd, scnhdr_int->s_vaddr, scnhdr_ext->s_vaddr);
 131   PUT_SCNHDR_PADDR (abfd, scnhdr_int->s_paddr, scnhdr_ext->s_paddr);
 132   PUT_SCNHDR_SIZE (abfd, scnhdr_int->s_size, scnhdr_ext->s_size);
 133   PUT_SCNHDR_SCNPTR (abfd, scnhdr_int->s_scnptr, scnhdr_ext->s_scnptr);
 134   PUT_SCNHDR_RELPTR (abfd, scnhdr_int->s_relptr, scnhdr_ext->s_relptr);
 135   PUT_SCNHDR_LNNOPTR (abfd, scnhdr_int->s_lnnoptr, scnhdr_ext->s_lnnoptr);
 136   PUT_SCNHDR_FLAGS (abfd, scnhdr_int->s_flags, scnhdr_ext->s_flags);
 137
 138   if (abfd->flags & EXEC_P && (strcmp (scnhdr_int->s_name, ".text") == 0))
 139     {
 140       /* DJGPP follows the same strategy as PE COFF.
 141          By inference from looking at MS output, the 32 bit field
 142          which is the combination of the number_of_relocs and
 143          number_of_linenos is used for the line number count in
 144          executables.  A 16-bit field won't do for cc1.  The MS
 145          document says that the number of relocs is zero for
 146          executables, but the 17-th bit has been observed to be there.
 147          Overflow is not an issue: a 4G-line program will overflow a
 148          bunch of other fields long before this!  */
 149       PUT_SCNHDR_NLNNO (abfd, (scnhdr_int->s_nlnno & 0xffff),
 150                         scnhdr_ext->s_nlnno);
 151       PUT_SCNHDR_NRELOC (abfd, (scnhdr_int->s_nlnno >> 16),
 152                          scnhdr_ext->s_nreloc);
 153     }
 154   else
 155     {
 156       /* DJGPP follows the same strategy as PE COFF.  */
 157       if (scnhdr_int->s_nlnno <= MAX_SCNHDR_NLNNO)
 158         PUT_SCNHDR_NLNNO (abfd, scnhdr_int->s_nlnno, scnhdr_ext->s_nlnno);
 159       else
 160         {
 161           char buf[sizeof (scnhdr_int->s_name) + 1];
 162
 163           memcpy (buf, scnhdr_int->s_name, sizeof (scnhdr_int->s_name));
 164           buf[sizeof (scnhdr_int->s_name)] = '\0';
 165           _bfd_error_handler
 166             /* xgettext:c-format */
 167             (_("%pB: warning: %s: line number overflow: 0x%lx > 0xffff"),
 168              abfd, buf, scnhdr_int->s_nlnno);
 169           bfd_set_error (bfd_error_file_truncated);
 170           PUT_SCNHDR_NLNNO (abfd, 0xffff, scnhdr_ext->s_nlnno);
 171           ret = 0;
 172         }
 173
 174       /* Although we could encode 0xffff relocs here, we do not, to be
 175          consistent with other parts of bfd.  Also it lets us warn, as
 176          we should never see 0xffff here w/o having the overflow flag
 177          set.  */
 178       if (scnhdr_int->s_nreloc < MAX_SCNHDR_NRELOC)
 179         PUT_SCNHDR_NRELOC (abfd, scnhdr_int->s_nreloc, scnhdr_ext->s_nreloc);
 180       else
 181         {
 182           /* DJGPP can deal with large #s of relocs, but not here.  */
 183           PUT_SCNHDR_NRELOC (abfd, 0xffff, scnhdr_ext->s_nreloc);
 184           scnhdr_int->s_flags |= IMAGE_SCN_LNK_NRELOC_OVFL;
 185           PUT_SCNHDR_FLAGS (abfd, scnhdr_int->s_flags, scnhdr_ext->s_flags);
 186         }
 187     }
 188
 189   return ret;
 190 }