libdw: Allow .debug_frame only Dwarf.

.debug_frame is useful independent from the other .debug sections.

Add a simplified variant of the addrcfi testcase dwarfcfi.
dwarfcfi only uses dwarf_frame calls and no dwfl helpers.

Signed-off-by: Mark Wielaard <[email protected]>

1 files changed, 175 insertions, 0 deletions

diff --git a/tests/dwarfcfi.c b/tests/dwarfcfi.c
new file mode 100644
index 00000000..db4a36ff
--- /dev/null
+++ b/tests/dwarfcfi.c
@@ -0,0 +1,175 @@
+/* Test program for DWARF (.debug_frame) CFI handling.
+   Copyright (C) 2009-2010, 2013, 2015, 2018 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file 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 of the License, or
+   (at your option) any later version.
+
+   elfutils 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.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+#include <assert.h>
+#include <inttypes.h>
+#include <error.h>
+#include ELFUTILS_HEADER(dw)
+#include <dwarf.h>
+#include <argp.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../libdw/known-dwarf.h"
+
+static const char *
+op_name (unsigned int code)
+{
+  static const char *const known[] =
+    {
+#define DWARF_ONE_KNOWN_DW_OP(NAME, CODE) [CODE] = #NAME,
+      DWARF_ALL_KNOWN_DW_OP
+#undef DWARF_ONE_KNOWN_DW_OP
+    };
+
+  if (likely (code < sizeof (known) / sizeof (known[0])))
+    return known[code];
+
+  return NULL;
+}
+
+static void
+print_detail (int result, const Dwarf_Op *ops, size_t nops)
+{
+  if (result < 0)
+    printf ("indeterminate (%s)\n", dwarf_errmsg (-1));
+  else if (nops == 0)
+    printf ("%s\n", ops == NULL ? "same_value" : "undefined");
+  else
+    {
+      printf ("%s expression:", result == 0 ? "location" : "value");
+      for (size_t i = 0; i < nops; ++i)
+	{
+	  printf (" %s", op_name(ops[i].atom));
+	  if (ops[i].number2 == 0)
+	    {
+	      if (ops[i].atom == DW_OP_addr)
+		printf ("(%#" PRIx64 ")", ops[i].number);
+	      else if (ops[i].number != 0)
+		printf ("(%" PRId64 ")", ops[i].number);
+	    }
+	  else
+	    printf ("(%" PRId64 ",%" PRId64 ")",
+		    ops[i].number, ops[i].number2);
+	}
+      puts ("");
+    }
+}
+
+static int
+handle_address (Dwarf_CFI *cfi, GElf_Addr pc)
+{
+  Dwarf_Frame *frame;
+  int result = dwarf_cfi_addrframe (cfi, pc, &frame);
+  if (result != 0)
+    {
+      printf ("dwarf_cfi_addrframe: %s\n", dwarf_errmsg (-1));
+      return 1;
+    }
+
+  Dwarf_Addr start = pc;
+  Dwarf_Addr end = pc;
+  bool signalp;
+  int ra_regno = dwarf_frame_info (frame, &start, &end, &signalp);
+
+  printf ("%#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "):\n",
+	  pc, start, end);
+
+  if (ra_regno < 0)
+    printf ("\treturn address register unavailable (%s)\n",
+	    dwarf_errmsg (-1));
+  else
+    printf ("\treturn address in reg%u%s\n",
+	    ra_regno, signalp ? " (signal frame)" : "");
+
+  // Point cfa_ops to dummy to match print_detail expectations.
+  // (nops == 0 && cfa_ops != NULL => "undefined")
+  Dwarf_Op dummy;
+  Dwarf_Op *cfa_ops = &dummy;
+  size_t cfa_nops;
+  result = dwarf_frame_cfa (frame, &cfa_ops, &cfa_nops);
+
+  printf ("\tCFA ");
+  print_detail (result, cfa_ops, cfa_nops);
+
+  // Print the location of the first 10 (DWARF nr) registers
+  for (int r = 0; r < 10; r++)
+    {
+      Dwarf_Op ops_mem[3];
+      Dwarf_Op *ops;
+      size_t nops;
+      printf ("\treg%d: ", r);
+      int reg_result = dwarf_frame_register (frame, r, ops_mem, &ops, &nops);
+      print_detail (reg_result, ops, nops);
+      result |= reg_result;
+    }
+
+  free (frame);
+  return result;
+}
+
+int
+main (int argc, char *argv[])
+{
+  if (argc <= 2)
+    error (EXIT_FAILURE, 0, "need file name argument and addresses");
+
+  int fd = open (argv[1], O_RDONLY);
+  if (fd == -1)
+    error (EXIT_FAILURE, errno, "cannot open input file `%s'", argv[1]);
+
+  elf_version (EV_CURRENT);
+
+  Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
+  if (elf == NULL)
+    error (EXIT_FAILURE, 0, "cannot create ELF descriptor: %s",
+	   elf_errmsg (-1));
+
+  Dwarf *dwarf = dwarf_begin_elf (elf, DWARF_C_READ, NULL);
+  if (dwarf == NULL)
+    error (EXIT_FAILURE, 0, "cannot create DWARF descriptor: %s",
+	   dwarf_errmsg (-1));
+
+  Dwarf_CFI *cfi = dwarf_getcfi (dwarf);
+  if (cfi == NULL)
+    error (EXIT_FAILURE, 0, "cannot get DWARF CFI from .dwarf_frame: %s",
+	   dwarf_errmsg (-1));
+
+  int result = 0;
+  int args = 2;
+  do
+    {
+      char *endp;
+      uintmax_t addr = strtoumax (argv[args], &endp, 0);
+      if (endp != argv[args])
+	result |= handle_address (cfi, addr);
+      else
+	result = 1;
+    }
+  while (args++ < argc - 1);
+
+  dwarf_end (dwarf);
+  elf_end (elf);
+
+  return result;
+}