aboutsummaryrefslogtreecommitdiff
path: root/libctf/ctf-subr.c
blob: 4e3803928bd4f6829eff3829efa66fee2a95fd14 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
/* Simple subrs.
   Copyright (C) 2019-2021 Free Software Foundation, Inc.

   This file is part of libctf.

   libctf is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License as published by the Free
   Software Foundation; either version 3, or (at your option) any later
   version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.  If not see
   <http://www.gnu.org/licenses/>.  */

#include <ctf-impl.h>
#ifdef HAVE_MMAP
#include <sys/mman.h>
#endif
#include <sys/types.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>

#ifndef ENOTSUP
#define ENOTSUP ENOSYS
#endif

int _libctf_version = CTF_VERSION;	      /* Library client version.  */
int _libctf_debug = 0;			      /* Debugging messages enabled.  */

/* Private, read-only mmap from a file, with fallback to copying.

   No handling of page-offset issues at all: the caller must allow for that. */

_libctf_malloc_ void *
ctf_mmap (size_t length, size_t offset, int fd)
{
  void *data;

#ifdef HAVE_MMAP
  data = mmap (NULL, length, PROT_READ, MAP_PRIVATE, fd, offset);
  if (data == MAP_FAILED)
    data = NULL;
#else
  if ((data = malloc (length)) != NULL)
    {
      if (ctf_pread (fd, data, length, offset) <= 0)
	{
	  free (data);
	  data = NULL;
	}
    }
#endif
  return data;
}

void
ctf_munmap (void *buf, size_t length _libctf_unused_)
{
#ifdef HAVE_MMAP
  (void) munmap (buf, length);
#else
  free (buf);
#endif
}

ssize_t
ctf_pread (int fd, void *buf, ssize_t count, off_t offset)
{
  ssize_t len;
  size_t acc = 0;
  char *data = (char *) buf;

#ifdef HAVE_PREAD
  while (count > 0)
    {
      errno = 0;
      if (((len = pread (fd, data, count, offset)) < 0) &&
	  errno != EINTR)
	  return len;
      if (errno == EINTR)
	continue;

      acc += len;
      if (len == 0)				/* EOF.  */
	return acc;

      count -= len;
      offset += len;
      data += len;
    }
  return acc;
#else
  off_t orig_off;

  if ((orig_off = lseek (fd, 0, SEEK_CUR)) < 0)
    return -1;
  if ((lseek (fd, offset, SEEK_SET)) < 0)
    return -1;

  while (count > 0)
    {
      errno = 0;
      if (((len = read (fd, data, count)) < 0) &&
	  errno != EINTR)
	  return len;
      if (errno == EINTR)
	continue;

      acc += len;
      if (len == 0)				/* EOF.  */
	break;

      count -= len;
      data += len;
    }
  if ((lseek (fd, orig_off, SEEK_SET)) < 0)
    return -1;					/* offset is smashed.  */
#endif

  return acc;
}

/* Set the CTF library client version to the specified version.  If version is
   zero, we just return the default library version number.  */
int
ctf_version (int version)
{
  if (version < 0)
    {
      errno = EINVAL;
      return -1;
    }

  if (version > 0)
    {
      /*  Dynamic version switching is not presently supported. */
      if (version != CTF_VERSION)
	{
	  errno = ENOTSUP;
	  return -1;
	}
      ctf_dprintf ("ctf_version: client using version %d\n", version);
      _libctf_version = version;
    }

  return _libctf_version;
}

void
libctf_init_debug (void)
{
  static int inited;
  if (!inited)
    {
      _libctf_debug = getenv ("LIBCTF_DEBUG") != NULL;
      inited = 1;
    }
}

void ctf_setdebug (int debug)
{
  /* Ensure that libctf_init_debug() has been called, so that we don't get our
     debugging-on-or-off smashed by the next call.  */

  libctf_init_debug();
  _libctf_debug = debug;
  ctf_dprintf ("CTF debugging set to %i\n", debug);
}

int ctf_getdebug (void)
{
  return _libctf_debug;
}

_libctf_printflike_ (1, 2)
void ctf_dprintf (const char *format, ...)
{
  if (_libctf_unlikely_ (_libctf_debug))
    {
      va_list alist;

      va_start (alist, format);
      fflush (stdout);
      (void) fputs ("libctf DEBUG: ", stderr);
      (void) vfprintf (stderr, format, alist);
      va_end (alist);
    }
}

/* This needs more attention to thread-safety later on.  */
static ctf_list_t open_errors;

/* Errors and warnings.  Report the warning or error to the list in FP (or the
   open errors list if NULL): if ERR is nonzero it is the errno to report to the
   debug stream instead of that recorded on fp.  */
_libctf_printflike_ (4, 5)
extern void
ctf_err_warn (ctf_dict_t *fp, int is_warning, int err,
	      const char *format, ...)
{
  va_list alist;
  ctf_err_warning_t *cew;

  /* Don't bother reporting errors here: we can't do much about them if they
     happen.  If we're so short of memory that a tiny malloc doesn't work, a
     vfprintf isn't going to work either and the caller will have to rely on the
     ENOMEM return they'll be getting in short order anyway.  */

  if ((cew = malloc (sizeof (ctf_err_warning_t))) == NULL)
    return;

  cew->cew_is_warning = is_warning;
  va_start (alist, format);
  if (vasprintf (&cew->cew_text, format, alist) < 0)
    {
      free (cew);
      va_end (alist);
      return;
    }
  va_end (alist);

  /* Include the error code only if there is one; if this is not a warning,
     only use the error code if it was explicitly passed and is nonzero.
     (Warnings may not have a meaningful error code, since the warning may not
     lead to unwinding up to the user.)  */
  if ((!is_warning && (err != 0 || (fp && ctf_errno (fp) != 0)))
      || (is_warning && err != 0))
    ctf_dprintf ("%s: %s (%s)\n", is_warning ? _("error") : _("warning"),
		 cew->cew_text, err != 0 ? ctf_errmsg (err)
		 : ctf_errmsg (ctf_errno (fp)));
  else
    ctf_dprintf ("%s: %s\n", is_warning ? _("error") : _("warning"),
		 cew->cew_text);

  if (fp != NULL)
    ctf_list_append (&fp->ctf_errs_warnings, cew);
  else
    ctf_list_append (&open_errors, cew);
}

/* Move all the errors/warnings from an fp into the open_errors.  */
void
ctf_err_warn_to_open (ctf_dict_t *fp)
{
  ctf_list_splice (&open_errors, &fp->ctf_errs_warnings);
}

/* Error-warning reporting: an 'iterator' that returns errors and warnings from
   the error/warning list, in order of emission.  Errors and warnings are popped
   after return: the caller must free the returned error-text pointer.

   An fp of NULL returns CTF-open-time errors from the open_errors variable
   above.

   The treatment of errors from this function itself is somewhat unusual: it
   will often be called on an error path, so we don't want to overwrite the
   ctf_errno unless we have no choice.  So, like ctf_bufopen et al, this
   function takes an errp pointer where errors are reported.  The pointer is
   optional: if not set, errors are reported via the fp (if non-NULL).  Calls
   with neither fp nor errp set are mildly problematic because there is no clear
   way to report end-of-iteration: you just have to assume that a NULL return
   means the end, and not an iterator error.  */

char *
ctf_errwarning_next (ctf_dict_t *fp, ctf_next_t **it, int *is_warning,
		     int *errp)
{
  ctf_next_t *i = *it;
  char *ret;
  ctf_list_t *errlist;
  ctf_err_warning_t *cew;

  if (fp)
    errlist = &fp->ctf_errs_warnings;
  else
    errlist = &open_errors;

  if (!i)
    {
      if ((i = ctf_next_create ()) == NULL)
	{
	  if (errp)
	    *errp = ENOMEM;
	  else if (fp)
	    ctf_set_errno (fp, ENOMEM);
	  return NULL;
	}

      i->cu.ctn_fp = fp;
      i->ctn_iter_fun = (void (*) (void)) ctf_errwarning_next;
      *it = i;
    }

  if ((void (*) (void)) ctf_errwarning_next != i->ctn_iter_fun)
    {
      if (errp)
	*errp = ECTF_NEXT_WRONGFUN;
      else if (fp)
	ctf_set_errno (fp, ECTF_NEXT_WRONGFUN);
      return NULL;
    }

  if (fp != i->cu.ctn_fp)
    {
      if (errp)
	*errp = ECTF_NEXT_WRONGFP;
      else if (fp)
	ctf_set_errno (fp, ECTF_NEXT_WRONGFP);
      return NULL;
    }

  cew = ctf_list_next (errlist);

  if (!cew)
    {
      ctf_next_destroy (i);
      *it = NULL;
      if (errp)
	*errp = ECTF_NEXT_END;
      else if (fp)
	ctf_set_errno (fp, ECTF_NEXT_END);
      return NULL;
    }

  if (is_warning)
    *is_warning = cew->cew_is_warning;
  ret = cew->cew_text;
  ctf_list_delete (errlist, cew);
  free (cew);
  return ret;
}

void
ctf_assert_fail_internal (ctf_dict_t *fp, const char *file, size_t line,
			  const char *exprstr)
{
  ctf_err_warn (fp, 0, ECTF_INTERNAL, _("%s: %lu: libctf assertion failed: %s"),
		file, (long unsigned int) line, exprstr);
  ctf_set_errno (fp, ECTF_INTERNAL);
}