1/* Align section.
2   Copyright (C) 2002, 2005 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4   Written by Ulrich Drepper <drepper@redhat.com>, 2002.
5
6   Red Hat elfutils is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by the
8   Free Software Foundation; version 2 of the License.
9
10   Red Hat elfutils is distributed in the hope that it will be useful, but
11   WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   General Public License for more details.
14
15   You should have received a copy of the GNU General Public License along
16   with Red Hat elfutils; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19   Red Hat elfutils is an included package of the Open Invention Network.
20   An included package of the Open Invention Network is a package for which
21   Open Invention Network licensees cross-license their patents.  No patent
22   license is granted, either expressly or impliedly, by designation as an
23   included package.  Should you wish to participate in the Open Invention
24   Network licensing program, please visit www.openinventionnetwork.com
25   <http://www.openinventionnetwork.com>.  */
26
27#ifdef HAVE_CONFIG_H
28# include <config.h>
29#endif
30
31#include <inttypes.h>
32#include <stdlib.h>
33#include <sys/param.h>
34
35#include <libasmP.h>
36#include <system.h>
37
38
39int
40asm_align (asmscn, value)
41     AsmScn_t *asmscn;
42     GElf_Word value;
43{
44  if (asmscn == NULL)
45    /* An earlier error.  */
46    return -1;
47
48      /* The alignment value must be a power of two.  */
49  if (unlikely (! powerof2 (value)))
50    {
51      __libasm_seterrno (ASM_E_INVALID);
52      return -1;
53    }
54
55  if (unlikely (asmscn->ctx->textp))
56    {
57      fprintf (asmscn->ctx->out.file, "\t.align %" PRId32 ", ",
58	       (int32_t) value);
59      if (asmscn->pattern->len == 1)
60	fprintf (asmscn->ctx->out.file, "%02hhx\n", asmscn->pattern->bytes[0]);
61      else
62	{
63	  fputc_unlocked ('"', asmscn->ctx->out.file);
64
65	  for (size_t cnt = 0; cnt < asmscn->pattern->len; ++cnt)
66	    fprintf (asmscn->ctx->out.file, "\\x%02hhx",
67		     asmscn->pattern->bytes[cnt]);
68
69	  fputs_unlocked ("\"\n", asmscn->ctx->out.file);
70	}
71      return 0;
72    }
73
74  rwlock_wrlock (asmscn->ctx->lock);
75
76  int result = 0;
77
78  /* Fillbytes necessary?  */
79  if ((asmscn->offset & (value - 1)) != 0)
80    {
81      /* Add fillbytes.  */
82      size_t cnt = value - (asmscn->offset & (value - 1));
83
84      /* Ensure there is enough room to add the fill bytes.  */
85      result = __libasm_ensure_section_space (asmscn, cnt);
86      if (result != 0)
87	goto out;
88
89      /* Fill in the bytes.  We align the pattern according to the
90	 current offset.  */
91      size_t byteptr = asmscn->offset % asmscn->pattern->len;
92
93      /* Update the total size.  */
94      asmscn->offset += cnt;
95
96      do
97	{
98	  asmscn->content->data[asmscn->content->len++]
99	    = asmscn->pattern->bytes[byteptr++];
100
101	  if (byteptr == asmscn->pattern->len)
102	    byteptr = 0;
103	}
104      while (--cnt > 0);
105    }
106
107  /* Remember the maximum alignment for this subsection.  */
108  if (asmscn->max_align < value)
109    {
110      asmscn->max_align = value;
111
112      /* Update the parent as well (if it exists).  */
113      if (asmscn->subsection_id != 0)
114	{
115	  rwlock_wrlock (asmscn->data.up->ctx->lock);
116
117	  if (asmscn->data.up->max_align < value)
118	    asmscn->data.up->max_align = value;
119
120	  rwlock_unlock (asmscn->data.up->ctx->lock);
121	}
122    }
123
124 out:
125  rwlock_unlock (asmscn->ctx->lock);
126
127  return result;
128}
129
130
131/* Ensure there are at least LEN bytes available in the output buffer
132   for ASMSCN.  */
133int
134__libasm_ensure_section_space (asmscn, len)
135     AsmScn_t *asmscn;
136     size_t len;
137{
138  /* The blocks with the section content are kept in a circular
139     single-linked list.  */
140  size_t size;
141
142  if (asmscn->content == NULL)
143    {
144      /* This is the first block.  */
145      size = MAX (2 * len, 960);
146
147      asmscn->content = (struct AsmData *) malloc (sizeof (struct AsmData)
148						   + size);
149      if (asmscn->content == NULL)
150	return -1;
151
152      asmscn->content->next = asmscn->content;
153    }
154  else
155    {
156      struct AsmData *newp;
157
158      if (asmscn->content->maxlen - asmscn->content->len >= len)
159	/* Nothing to do, there is enough space.  */
160	return 0;
161
162      size = MAX (2 *len, MIN (32768, 2 * asmscn->offset));
163
164      newp = (struct AsmData *) malloc (sizeof (struct AsmData) + size);
165      if (newp == NULL)
166	return -1;
167
168      newp->next = asmscn->content->next;
169      asmscn->content = asmscn->content->next = newp;
170    }
171
172  asmscn->content->len = 0;
173  asmscn->content->maxlen = size;
174
175  return 0;
176}
177