glibc/debug/pcprofiledump.c

/* Dump information generated by PC profiling.
   Copyright (C) 1999-2024 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

/* This is mainly an example.  It shows how programs which want to use
   the information should read the file.  */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <argp.h>
#include <byteswap.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libintl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>

#include "../version.h"

#define PACKAGE _libc_intl_domainname

#ifndef _
# define _(Str) gettext (Str)
#endif

#ifndef N_
# define N_(Str) Str
#endif

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { "unbuffered", 'u', NULL, 0, N_("Don't buffer output") },
  { NULL, 0, NULL, 0, NULL }
};

/* Short description of program.  */
static const char doc[] = N_("Dump information generated by PC profiling.");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("[FILE]");

/* Function to print some extra text in the help message.  */
static char *more_help (int key, const char *text, void *input);

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, NULL, more_help
};

/* Try to read SIZE bytes from FD and store them on BUF.  Terminate
   the process upon read error.  Also terminate the process if less
   than SIZE bytes are remaining in the file.  If !IN_HEADER, do not
   terminate the process if the end of the file is encountered
   immediately, before any bytes are read.

   Returns true if SIZE bytes have been read, and false if no bytes
   have been read due to an end-of-file condition.  */
static bool
read_exactly (int fd, void *buffer, size_t size, bool in_header)
{
  char *p = buffer;
  char *end = p + size;
  while (p < end)
    {
      ssize_t ret = TEMP_FAILURE_RETRY (read (fd, p, end - p));
      if (ret < 0)
	{
	  if (in_header)
	    error (EXIT_FAILURE, errno, _("cannot read header"));
	  else
	    error (EXIT_FAILURE, errno,  _("cannot read pointer pair"));
	}
      if (ret == 0)
	{
	  if (p == buffer && !in_header)
	    /* Nothing has been read.  */
	    return false;
	  if (in_header)
	    error (EXIT_FAILURE, 0, _("unexpected end of file in header"));
	  else
	    error (EXIT_FAILURE, 0,
		   _("unexpected end of file in pointer pair"));
	}
      p += ret;
    }
  return true;
}

int
main (int argc, char *argv[])
{
  /* Set locale via LC_ALL.  */
  setlocale (LC_ALL, "");

  /* Set the text message domain.  */
  textdomain (PACKAGE);

  /* Parse and process arguments.  */
  int remaining;
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  int fd;
  if (remaining == argc)
    fd = STDIN_FILENO;
  else if (remaining + 1 != argc)
    {
      argp_help (&argp, stdout, ARGP_HELP_SEE | ARGP_HELP_EXIT_ERR,
		 program_invocation_short_name);
      exit (1);
    }
  else
    {
      /* Open the given file.  */
      fd = open (argv[remaining], O_RDONLY);

      if (fd == -1)
	error (EXIT_FAILURE, errno, _("cannot open input file"));
    }

  /* Read the first 4-byte word.  It contains the information about
     the word size and the endianness.  */
  uint32_t word;
  read_exactly (fd, &word, sizeof (word), true);

  /* Check whether we have to swap the byte order.  */
  int must_swap = (word & 0x0fffffff) == bswap_32 (0xdeb00000);
  if (must_swap)
    word = bswap_32 (word);

  /* We have two loops, one for 32 bit pointers, one for 64 bit pointers.  */
  if (word == 0xdeb00004)
    {
      uint32_t ptrs[2];

      while (1)
	{
	  if (!read_exactly (fd, ptrs, sizeof (ptrs), false))
	    break;

	  printf ("this = %#010" PRIx32 ", caller = %#010" PRIx32 "\n",
		  must_swap ? bswap_32 (ptrs[0]) : ptrs[0],
		  must_swap ? bswap_32 (ptrs[1]) : ptrs[1]);
	}
    }
  else if (word == 0xdeb00008)
    {
      uint64_t ptrs[2];

      while (1)
	{
	  if (!read_exactly (fd, ptrs, sizeof (ptrs), false))
	    break;

	  printf ("this = %#018" PRIx64 ", caller = %#018" PRIx64 "\n",
		  must_swap ? bswap_64 (ptrs[0]) : ptrs[0],
		  must_swap ? bswap_64 (ptrs[1]) : ptrs[1]);
	}
    }
  else
    /* This should not happen.  */
    error (EXIT_FAILURE, 0, _("invalid pointer size"));

  /* Clean up.  */
  close (fd);

  return 0;
}

static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case 'u':
      setbuf (stdout, NULL);
      break;
    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}

static char *
more_help (int key, const char *text, void *input)
{
  char *tp = NULL;
  switch (key)
    {
    case ARGP_KEY_HELP_EXTRA:
      /* We print some extra information.  */
      if (asprintf (&tp, gettext ("\
For bug reporting instructions, please see:\n\
%s.\n"), REPORT_BUGS_TO) < 0)
	return NULL;
      return tp;
    default:
      break;
    }
  return (char *) text;
}

/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "pcprofiledump %s%s\n", PKGVERSION, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2024");
  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}