xref: /third_party/elfutils/tests/next_cfi.c (revision da0c48c4)
1/* Test program for dwarf_next_cfi
2   Copyright (C) 2018 Red Hat, Inc.
3   This file is part of elfutils.
4
5   This file is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   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
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19#include <assert.h>
20#include <inttypes.h>
21#include ELFUTILS_HEADER(dw)
22#include <dwarf.h>
23#include <argp.h>
24#include <stdbool.h>
25#include <stdio.h>
26#include <sys/types.h>
27#include <sys/stat.h>
28#include <fcntl.h>
29#include <locale.h>
30#include <stdlib.h>
31#include <string.h>
32#include <unistd.h>
33#include "system.h"
34
35void
36handle_section (char *name, const unsigned char e_ident[],
37		Elf_Scn *scn, const bool is_eh)
38{
39  if (is_eh)
40    printf (".eh_frame\n");
41  else
42    printf (".debug_frame\n");
43
44  GElf_Shdr mem;
45  GElf_Shdr *shdr = gelf_getshdr (scn, &mem);
46  if (shdr == NULL)
47    error (EXIT_FAILURE, 0, "Couldn't get section header: %s",
48	   elf_errmsg (-1));
49  if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
50    {
51      if (elf_compress (scn, 0, 0) < 0)
52	error (EXIT_FAILURE, 0, "Couldn't decompress section: %s",
53	       elf_errmsg (-1));
54    }
55  else if (name[0] == '.' && name[1] == 'z')
56    {
57      if (elf_compress_gnu (scn, 0, 0) < 0)
58	error (EXIT_FAILURE, 0, "Couldn't decompress section: %s",
59	       elf_errmsg (-1));
60    }
61
62  Elf_Data *data = elf_getdata (scn, NULL);
63  if (data == NULL || data->d_buf == NULL)
64    error (EXIT_FAILURE, 0, "no section data");
65
66  int res;
67  Dwarf_Off off;
68  Dwarf_Off next_off = 0;
69  Dwarf_CFI_Entry entry;
70  while ((res = dwarf_next_cfi (e_ident, data, is_eh, off = next_off,
71				&next_off, &entry)) == 0)
72    {
73      printf ("[%" PRId64 "] ", off);
74      if (dwarf_cfi_cie_p (&entry))
75	printf ("CIE augmentation=\"%s\"\n", entry.cie.augmentation);
76      else
77	{
78	  printf ("FDE cie=[%" PRId64 "]\n", entry.fde.CIE_pointer);
79
80	  Dwarf_Off cie_off = entry.fde.CIE_pointer;
81	  Dwarf_Off cie_off_next;
82	  Dwarf_CFI_Entry cie_entry;
83	  if (dwarf_next_cfi (e_ident, data, is_eh, cie_off, &cie_off_next,
84			      &cie_entry) != 0
85	      || !dwarf_cfi_cie_p (&cie_entry))
86	    error (EXIT_FAILURE, 0, "FDE doesn't point to CIE");
87	}
88    }
89
90  if (res < 0)
91    error (EXIT_FAILURE, 0, "dwarf_next_cfi failed: %s\n",
92	   dwarf_errmsg (-1));
93}
94
95int
96main (int argc, char *argv[])
97{
98  if (argc != 2)
99    error (EXIT_FAILURE, 0, "need file name argument");
100
101  const char *file = argv[1];
102  printf ("%s\n", file);
103
104  int fd = open (file, O_RDONLY);
105  if (fd == -1)
106    error (EXIT_FAILURE, errno, "cannot open input file `%s'", file);
107
108  elf_version (EV_CURRENT);
109
110  Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
111  if (elf == NULL)
112    error (EXIT_FAILURE, 0, "cannot create ELF descriptor: %s",
113	   elf_errmsg (-1));
114
115  size_t esize;
116  const unsigned char *ident = (const unsigned char *) elf_getident (elf,
117								     &esize);
118  if (ident == NULL || esize < EI_NIDENT)
119    error (EXIT_FAILURE, 0, "no, or too small, ELF ident");
120
121  GElf_Ehdr ehdr;
122  if (gelf_getehdr (elf, &ehdr) == NULL)
123    error (EXIT_FAILURE, 0, "cannot get the ELF header: %s\n",
124	   elf_errmsg (-1));
125
126  size_t strndx = ehdr.e_shstrndx;
127
128  Elf_Scn *scn = NULL;
129  while ((scn = elf_nextscn (elf, scn)) != NULL)
130    {
131      GElf_Shdr shdr;
132      if (gelf_getshdr (scn, &shdr) != NULL)
133	{
134	  char *name = elf_strptr (elf, strndx, (size_t) shdr.sh_name);
135	  if (name != NULL && shdr.sh_type == SHT_PROGBITS)
136	    {
137	      if (strcmp (name, ".eh_frame") == 0)
138		handle_section (name, ident, scn, true);
139	      if (strcmp (name, ".debug_frame") == 0
140		  || strcmp (name, ".zdebug_frame") == 0)
141		handle_section (name, ident, scn, false);
142	    }
143	}
144    }
145
146  elf_end (elf);
147  close (fd);
148
149  return 0;
150}
151