1 /* Create new COMMON symbol.
2 Copyright (C) 2002, 2016 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2002.
5
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
8
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
12
13 or
14
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
18
19 or both in parallel, as here.
20
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
25
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
29
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33
34 #include <inttypes.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38
39 #include <libasmP.h>
40 #include <system.h>
41
42
43 /* Object for special COMMON section. */
44 static const AsmScn_t __libasm_com_scn =
45 {
46 .data = {
47 .main = {
48 .scn = ASM_COM_SCN
49 }
50 }
51 };
52
53
54 AsmSym_t *
asm_newcomsym(AsmCtx_t * ctx,const char * name,GElf_Xword size,GElf_Addr align)55 asm_newcomsym (AsmCtx_t *ctx, const char *name, GElf_Xword size,
56 GElf_Addr align)
57 {
58 AsmSym_t *result;
59
60 if (ctx == NULL)
61 /* Something went wrong before. */
62 return NULL;
63
64 /* Common symbols are public. Therefore the user must provide a
65 name. */
66 if (name == NULL)
67 {
68 __libasm_seterrno (ASM_E_INVALID);
69 return NULL;
70 }
71
72 rwlock_wrlock (ctx->lock);
73
74 result = (AsmSym_t *) malloc (sizeof (AsmSym_t));
75 if (result == NULL)
76 return NULL;
77
78 result->scn = (AsmScn_t *) &__libasm_com_scn;
79 result->size = size;
80 /* XXX Do we have to allow a different type? */
81 result->type = STT_OBJECT;
82 /* XXX Do we have to allow a different binding? */
83 result->binding = STB_GLOBAL;
84 result->symidx = 0;
85 result->strent = dwelf_strtab_add (ctx->symbol_strtab, name);
86
87 /* The value of a COM symbol is the alignment. Since there are no
88 subsection and the initial offset of the section is 0 we can get
89 the alignment recorded by storing it into the offset field. */
90 result->offset = align;
91
92 if (unlikely (ctx->textp))
93 fprintf (ctx->out.file, "\t.comm %s, %" PRIuMAX ", %" PRIuMAX "\n",
94 name, (uintmax_t) size, (uintmax_t) align);
95 else
96 {
97 /* Put the symbol in the hash table so that we can later find it. */
98 if (asm_symbol_tab_insert (&ctx->symbol_tab, elf_hash (name), result)
99 != 0)
100 {
101 /* The symbol already exists. */
102 __libasm_seterrno (ASM_E_DUPLSYM);
103 free (result);
104 result = NULL;
105 }
106 else if (name != NULL && asm_emit_symbol_p (name))
107 /* Only count non-private symbols. */
108 ++ctx->nsymbol_tab;
109 }
110
111 rwlock_unlock (ctx->lock);
112
113 return result;
114 }
115