bfd/coff-go32.c

   1 /* BFD back-end for Intel 386 COFF files (DJGPP variant).
   2    Copyright (C) 1990-2023 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   return true;
  84 }
  85
  86 void
  87 _bfd_go32_swap_scnhdr_in (bfd * abfd, void * ext, void * in)
  88 {
  89   SCNHDR *scnhdr_ext = (SCNHDR *) ext;
  90   struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
  91
  92   memcpy (scnhdr_int->s_name, scnhdr_ext->s_name, sizeof (scnhdr_int->s_name));
  93
  94   scnhdr_int->s_vaddr = GET_SCNHDR_VADDR (abfd, scnhdr_ext->s_vaddr);
  95   scnhdr_int->s_paddr = GET_SCNHDR_PADDR (abfd, scnhdr_ext->s_paddr);
  96   scnhdr_int->s_size = GET_SCNHDR_SIZE (abfd, scnhdr_ext->s_size);
  97
  98   scnhdr_int->s_scnptr = GET_SCNHDR_SCNPTR (abfd, scnhdr_ext->s_scnptr);
  99   scnhdr_int->s_relptr = GET_SCNHDR_RELPTR (abfd, scnhdr_ext->s_relptr);
 100   scnhdr_int->s_lnnoptr = GET_SCNHDR_LNNOPTR (abfd, scnhdr_ext->s_lnnoptr);
 101   scnhdr_int->s_flags = GET_SCNHDR_FLAGS (abfd, scnhdr_ext->s_flags);
 102   scnhdr_int->s_nreloc = GET_SCNHDR_NRELOC (abfd, scnhdr_ext->s_nreloc);
 103   scnhdr_int->s_nlnno = GET_SCNHDR_NLNNO (abfd, scnhdr_ext->s_nlnno);
 104
 105   /* DJGPP follows the same strategy as PE COFF.
 106      Iff the file is an executable then the higher 16 bits
 107      of the line number have been stored in the relocation
 108      counter field.  */
 109   if (abfd->flags & EXEC_P && (strcmp (scnhdr_ext->s_name, ".text") == 0))
 110     {
 111       scnhdr_int->s_nlnno
 112         = (GET_SCNHDR_NRELOC (abfd, scnhdr_ext->s_nreloc) << 16)
 113           + GET_SCNHDR_NLNNO (abfd, scnhdr_ext->s_nlnno);
 114       scnhdr_int->s_nreloc = 0;
 115     }
 116 }
 117
 118 unsigned int
 119 _bfd_go32_swap_scnhdr_out (bfd * abfd, void * in, void * out)
 120 {
 121   struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
 122   SCNHDR *scnhdr_ext = (SCNHDR *) out;
 123   unsigned int ret = bfd_coff_scnhsz (abfd);
 124
 125   memcpy (scnhdr_ext->s_name, scnhdr_int->s_name, sizeof (scnhdr_int->s_name));
 126
 127   PUT_SCNHDR_VADDR (abfd, scnhdr_int->s_vaddr, scnhdr_ext->s_vaddr);
 128   PUT_SCNHDR_PADDR (abfd, scnhdr_int->s_paddr, scnhdr_ext->s_paddr);
 129   PUT_SCNHDR_SIZE (abfd, scnhdr_int->s_size, scnhdr_ext->s_size);
 130   PUT_SCNHDR_SCNPTR (abfd, scnhdr_int->s_scnptr, scnhdr_ext->s_scnptr);
 131   PUT_SCNHDR_RELPTR (abfd, scnhdr_int->s_relptr, scnhdr_ext->s_relptr);
 132   PUT_SCNHDR_LNNOPTR (abfd, scnhdr_int->s_lnnoptr, scnhdr_ext->s_lnnoptr);
 133   PUT_SCNHDR_FLAGS (abfd, scnhdr_int->s_flags, scnhdr_ext->s_flags);
 134
 135   if (abfd->flags & EXEC_P && (strcmp (scnhdr_int->s_name, ".text") == 0))
 136     {
 137       /* DJGPP follows the same strategy as PE COFF.
 138          By inference from looking at MS output, the 32 bit field
 139          which is the combination of the number_of_relocs and
 140          number_of_linenos is used for the line number count in
 141          executables.  A 16-bit field won't do for cc1.  The MS
 142          document says that the number of relocs is zero for
 143          executables, but the 17-th bit has been observed to be there.
 144          Overflow is not an issue: a 4G-line program will overflow a
 145          bunch of other fields long before this!  */
 146       PUT_SCNHDR_NLNNO (abfd, (scnhdr_int->s_nlnno & 0xffff),
 147                         scnhdr_ext->s_nlnno);
 148       PUT_SCNHDR_NRELOC (abfd, (scnhdr_int->s_nlnno >> 16),
 149                          scnhdr_ext->s_nreloc);
 150     }
 151   else
 152     {
 153       /* DJGPP follows the same strategy as PE COFF.  */
 154       if (scnhdr_int->s_nlnno <= MAX_SCNHDR_NLNNO)
 155         PUT_SCNHDR_NLNNO (abfd, scnhdr_int->s_nlnno, scnhdr_ext->s_nlnno);
 156       else
 157         {
 158           char buf[sizeof (scnhdr_int->s_name) + 1];
 159
 160           memcpy (buf, scnhdr_int->s_name, sizeof (scnhdr_int->s_name));
 161           buf[sizeof (scnhdr_int->s_name)] = '\0';
 162           _bfd_error_handler
 163             /* xgettext:c-format */
 164             (_("%pB: warning: %s: line number overflow: 0x%lx > 0xffff"),
 165              abfd, buf, scnhdr_int->s_nlnno);
 166           bfd_set_error (bfd_error_file_truncated);
 167           PUT_SCNHDR_NLNNO (abfd, 0xffff, scnhdr_ext->s_nlnno);
 168           ret = 0;
 169         }
 170
 171       /* Although we could encode 0xffff relocs here, we do not, to be
 172          consistent with other parts of bfd.  Also it lets us warn, as
 173          we should never see 0xffff here w/o having the overflow flag
 174          set.  */
 175       if (scnhdr_int->s_nreloc < MAX_SCNHDR_NRELOC)
 176         PUT_SCNHDR_NRELOC (abfd, scnhdr_int->s_nreloc, scnhdr_ext->s_nreloc);
 177       else
 178         {
 179           /* DJGPP can deal with large #s of relocs, but not here.  */
 180           PUT_SCNHDR_NRELOC (abfd, 0xffff, scnhdr_ext->s_nreloc);
 181           scnhdr_int->s_flags |= IMAGE_SCN_LNK_NRELOC_OVFL;
 182           PUT_SCNHDR_FLAGS (abfd, scnhdr_int->s_flags, scnhdr_ext->s_flags);
 183         }
 184     }
 185
 186   return ret;
 187 }