xref: /third_party/elfutils/tests/dwarfcfi.c (revision da0c48c4)
1/* Test program for DWARF (.debug_frame) CFI handling.
2   Copyright (C) 2009-2010, 2013, 2015, 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 <stdio.h>
25#include <sys/types.h>
26#include <sys/stat.h>
27#include <fcntl.h>
28#include <locale.h>
29#include <stdlib.h>
30#include <string.h>
31
32#include "system.h"
33#include "../libdw/known-dwarf.h"
34
35static const char *
36op_name (unsigned int code)
37{
38  static const char *const known[] =
39    {
40#define DWARF_ONE_KNOWN_DW_OP(NAME, CODE) [CODE] = #NAME,
41      DWARF_ALL_KNOWN_DW_OP
42#undef DWARF_ONE_KNOWN_DW_OP
43    };
44
45  if (likely (code < sizeof (known) / sizeof (known[0])))
46    return known[code];
47
48  return NULL;
49}
50
51static void
52print_detail (int result, const Dwarf_Op *ops, size_t nops)
53{
54  if (result < 0)
55    printf ("indeterminate (%s)\n", dwarf_errmsg (-1));
56  else if (nops == 0)
57    printf ("%s\n", ops == NULL ? "same_value" : "undefined");
58  else
59    {
60      printf ("%s expression:", result == 0 ? "location" : "value");
61      for (size_t i = 0; i < nops; ++i)
62	{
63	  printf (" %s", op_name(ops[i].atom));
64	  if (ops[i].number2 == 0)
65	    {
66	      if (ops[i].atom == DW_OP_addr)
67		printf ("(%#" PRIx64 ")", ops[i].number);
68	      else if (ops[i].number != 0)
69		printf ("(%" PRId64 ")", ops[i].number);
70	    }
71	  else
72	    printf ("(%" PRId64 ",%" PRId64 ")",
73		    ops[i].number, ops[i].number2);
74	}
75      puts ("");
76    }
77}
78
79static int
80handle_address (Dwarf_CFI *cfi, GElf_Addr pc)
81{
82  Dwarf_Frame *frame;
83  int result = dwarf_cfi_addrframe (cfi, pc, &frame);
84  if (result != 0)
85    {
86      printf ("dwarf_cfi_addrframe: %s\n", dwarf_errmsg (-1));
87      return 1;
88    }
89
90  Dwarf_Addr start = pc;
91  Dwarf_Addr end = pc;
92  bool signalp;
93  int ra_regno = dwarf_frame_info (frame, &start, &end, &signalp);
94
95  printf ("%#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "):\n",
96	  pc, start, end);
97
98  if (ra_regno < 0)
99    printf ("\treturn address register unavailable (%s)\n",
100	    dwarf_errmsg (-1));
101  else
102    printf ("\treturn address in reg%u%s\n",
103	    ra_regno, signalp ? " (signal frame)" : "");
104
105  // Point cfa_ops to dummy to match print_detail expectations.
106  // (nops == 0 && cfa_ops != NULL => "undefined")
107  Dwarf_Op dummy;
108  Dwarf_Op *cfa_ops = &dummy;
109  size_t cfa_nops;
110  result = dwarf_frame_cfa (frame, &cfa_ops, &cfa_nops);
111
112  printf ("\tCFA ");
113  print_detail (result, cfa_ops, cfa_nops);
114
115  // Print the location of the first 10 (DWARF nr) registers
116  for (int r = 0; r < 10; r++)
117    {
118      Dwarf_Op ops_mem[3];
119      Dwarf_Op *ops;
120      size_t nops;
121      printf ("\treg%d: ", r);
122      int reg_result = dwarf_frame_register (frame, r, ops_mem, &ops, &nops);
123      print_detail (reg_result, ops, nops);
124      result |= reg_result;
125    }
126
127  free (frame);
128  return result;
129}
130
131int
132main (int argc, char *argv[])
133{
134  if (argc <= 2)
135    error (EXIT_FAILURE, 0, "need file name argument and addresses");
136
137  int fd = open (argv[1], O_RDONLY);
138  if (fd == -1)
139    error (EXIT_FAILURE, errno, "cannot open input file `%s'", argv[1]);
140
141  elf_version (EV_CURRENT);
142
143  Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
144  if (elf == NULL)
145    error (EXIT_FAILURE, 0, "cannot create ELF descriptor: %s",
146	   elf_errmsg (-1));
147
148  Dwarf *dwarf = dwarf_begin_elf (elf, DWARF_C_READ, NULL);
149  if (dwarf == NULL)
150    error (EXIT_FAILURE, 0, "cannot create DWARF descriptor: %s",
151	   dwarf_errmsg (-1));
152
153  Dwarf_CFI *cfi = dwarf_getcfi (dwarf);
154  if (cfi == NULL)
155    error (EXIT_FAILURE, 0, "cannot get DWARF CFI from .dwarf_frame: %s",
156	   dwarf_errmsg (-1));
157
158  int result = 0;
159  int args = 2;
160  do
161    {
162      char *endp;
163      uintmax_t addr = strtoumax (argv[args], &endp, 0);
164      if (endp != argv[args])
165	result |= handle_address (cfi, addr);
166      else
167	result = 1;
168    }
169  while (args++ < argc - 1);
170
171  dwarf_end (dwarf);
172  elf_end (elf);
173
174  return result;
175}
176