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 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 }