gdbserver/gdbreplay.cc - binutils-gdb - Git at Google

 /* Replay a remote debug session logfile for GDB.
    Copyright (C) 1996-2024 Free Software Foundation, Inc.
    Written by Fred Fish (fnf@cygnus.com) from pieces of gdbserver.

    This file is part of GDB.

    This program 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.

    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.  If not, see <http://www.gnu.org/licenses/>.  */

 #undef PACKAGE
 #undef PACKAGE_NAME
 #undef PACKAGE_VERSION
 #undef PACKAGE_STRING
 #undef PACKAGE_TARNAME

 #include <config.h>
 #include "gdbsupport/version.h"

 #if HAVE_SYS_FILE_H
 #include <sys/file.h>
 #endif
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
 #include <ctype.h>
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
 #include <unistd.h>
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif
 #if HAVE_NETDB_H
 #include <netdb.h>
 #endif
 #if HAVE_NETINET_TCP_H
 #include <netinet/tcp.h>
 #endif

 #if USE_WIN32API
 #include <ws2tcpip.h>
 #endif

 #include "gdbsupport/netstuff.h"
 #include "gdbsupport/rsp-low.h"

 #ifndef HAVE_SOCKLEN_T
 typedef int socklen_t;
 #endif

 /* Sort of a hack... */
 #define EOL (EOF - 1)

 static int remote_desc_in;
 static int remote_desc_out;

 static void
 sync_error (FILE *fp, const char *desc, int expect, int got)
 {
   fprintf (stderr, "\n%s\n", desc);
   fprintf (stderr, "At logfile offset %ld, expected '0x%x' got '0x%x'\n",
 	   ftell (fp), expect, got);
   fflush (stderr);
   exit (1);
 }

 static void
 remote_error (const char *desc)
 {
   fprintf (stderr, "\n%s\n", desc);
   fflush (stderr);
   exit (1);
 }

 static void
 remote_close (void)
 {
 #ifdef USE_WIN32API
   gdb_assert (remote_desc_in == remote_desc_out);
   closesocket (remote_desc_in);
 #else
   close (remote_desc_in);
   if (remote_desc_in != remote_desc_out)
     close (remote_desc_out);
 #endif
 }

 /* Open a connection to a remote debugger.
    NAME is the filename used for communication.  */

 static void
 remote_open (const char *name)
 {
 #ifndef USE_WIN32API
   if (strcmp (name, "-") == 0)
     {
       remote_desc_in = 0;
       remote_desc_out = 1;
       return;
     }
 #endif

   const char *last_colon = strrchr (name, ':');

   if (last_colon == NULL)
     {
       fprintf (stderr, "%s: Must specify tcp connection as host:addr\n", name);
       fflush (stderr);
       exit (1);
     }

 #ifdef USE_WIN32API
   static int winsock_initialized;
 #endif
   int tmp;
   int tmp_desc;
   struct addrinfo hint;
   struct addrinfo *ainfo;

   memset (&hint, 0, sizeof (hint));
   /* Assume no prefix will be passed, therefore we should use
      AF_UNSPEC.  */
   hint.ai_family = AF_UNSPEC;
   hint.ai_socktype = SOCK_STREAM;
   hint.ai_protocol = IPPROTO_TCP;

   parsed_connection_spec parsed = parse_connection_spec (name, &hint);

   if (parsed.port_str.empty ())
     error (_("Missing port on hostname '%s'"), name);

 #ifdef USE_WIN32API
   if (!winsock_initialized)
     {
       WSADATA wsad;

       WSAStartup (MAKEWORD (1, 0), &wsad);
       winsock_initialized = 1;
     }
 #endif

   int r = getaddrinfo (parsed.host_str.c_str (), parsed.port_str.c_str (),
 		       &hint, &ainfo);

   if (r != 0)
     {
       fprintf (stderr, "%s:%s: cannot resolve name: %s\n",
 	       parsed.host_str.c_str (), parsed.port_str.c_str (),
 	       gai_strerror (r));
       fflush (stderr);
       exit (1);
     }

   scoped_free_addrinfo free_ainfo (ainfo);

   struct addrinfo *p;

   for (p = ainfo; p != NULL; p = p->ai_next)
     {
       tmp_desc = socket (p->ai_family, p->ai_socktype, p->ai_protocol);

       if (tmp_desc >= 0)
 	break;
     }

   if (p == NULL)
     perror_with_name ("Cannot open socket");

   /* Allow rapid reuse of this port. */
   tmp = 1;
   setsockopt (tmp_desc, SOL_SOCKET, SO_REUSEADDR, (char *) &tmp,
 	      sizeof (tmp));

   switch (p->ai_family)
     {
     case AF_INET:
       ((struct sockaddr_in *) p->ai_addr)->sin_addr.s_addr = INADDR_ANY;
       break;
     case AF_INET6:
       ((struct sockaddr_in6 *) p->ai_addr)->sin6_addr = in6addr_any;
       break;
     default:
       fprintf (stderr, "Invalid 'ai_family' %d\n", p->ai_family);
       exit (1);
     }

   if (bind (tmp_desc, p->ai_addr, p->ai_addrlen) != 0)
     perror_with_name ("Can't bind address");

   if (p->ai_socktype == SOCK_DGRAM)
     remote_desc_in = tmp_desc;
   else
     {
       struct sockaddr_storage sockaddr;
       socklen_t sockaddrsize = sizeof (sockaddr);
       char orig_host[GDB_NI_MAX_ADDR], orig_port[GDB_NI_MAX_PORT];

       if (listen (tmp_desc, 1) != 0)
 	perror_with_name ("Can't listen on socket");

       remote_desc_in = accept (tmp_desc, (struct sockaddr *) &sockaddr,
 			       &sockaddrsize);

       if (remote_desc_in == -1)
 	perror_with_name ("Accept failed");

       /* Enable TCP keep alive process. */
       tmp = 1;
       setsockopt (tmp_desc, SOL_SOCKET, SO_KEEPALIVE,
 		  (char *) &tmp, sizeof (tmp));

       /* Tell TCP not to delay small packets.  This greatly speeds up
 	 interactive response. */
       tmp = 1;
       setsockopt (remote_desc_in, IPPROTO_TCP, TCP_NODELAY,
 		  (char *) &tmp, sizeof (tmp));

       if (getnameinfo ((struct sockaddr *) &sockaddr, sockaddrsize,
 		       orig_host, sizeof (orig_host),
 		       orig_port, sizeof (orig_port),
 		       NI_NUMERICHOST | NI_NUMERICSERV) == 0)
 	{
 	  fprintf (stderr, "Remote debugging from host %s, port %s\n",
 		   orig_host, orig_port);
 	  fflush (stderr);
 	}

 #ifndef USE_WIN32API
       close (tmp_desc);		/* No longer need this */

       signal (SIGPIPE, SIG_IGN);	/* If we don't do this, then
 					   gdbreplay simply exits when
 					   the remote side dies.  */
 #else
       closesocket (tmp_desc);	/* No longer need this */
 #endif
     }

 #if defined(F_SETFL) && defined (FASYNC)
   fcntl (remote_desc_in, F_SETFL, FASYNC);
 #endif
   remote_desc_out = remote_desc_in;

   fprintf (stderr, "Replay logfile using %s\n", name);
   fflush (stderr);
 }

 static int
 logchar (FILE *fp)
 {
   int ch;
   int ch2;

   ch = fgetc (fp);
   if (ch != '\r')
     {
       fputc (ch, stderr);
       fflush (stderr);
     }
   switch (ch)
     {
       /* Treat \r\n as a newline.  */
     case '\r':
       ch = fgetc (fp);
       if (ch == '\n')
 	ch = EOL;
       else
 	{
 	  ungetc (ch, fp);
 	  ch = '\r';
 	}
       fputc (ch == EOL ? '\n' : '\r', stderr);
       fflush (stderr);
       break;
     case '\n':
       ch = EOL;
       break;
     case '\\':
       ch = fgetc (fp);
       fputc (ch, stderr);
       fflush (stderr);
       switch (ch)
 	{
 	case '\\':
 	  break;
 	case 'b':
 	  ch = '\b';
 	  break;
 	case 'f':
 	  ch = '\f';
 	  break;
 	case 'n':
 	  ch = '\n';
 	  break;
 	case 'r':
 	  ch = '\r';
 	  break;
 	case 't':
 	  ch = '\t';
 	  break;
 	case 'v':
 	  ch = '\v';
 	  break;
 	case 'x':
 	  ch2 = fgetc (fp);
 	  fputc (ch2, stderr);
 	  fflush (stderr);
 	  ch = fromhex (ch2) << 4;
 	  ch2 = fgetc (fp);
 	  fputc (ch2, stderr);
 	  fflush (stderr);
 	  ch |= fromhex (ch2);
 	  break;
 	default:
 	  /* Treat any other char as just itself */
 	  break;
 	}
     default:
       break;
     }
   return (ch);
 }

 static int
 gdbchar (int desc)
 {
   unsigned char fromgdb;

   if (read (desc, &fromgdb, 1) != 1)
     return -1;
   else
     return fromgdb;
 }

 /* Accept input from gdb and match with chars from fp (after skipping one
    blank) up until a \n is read from fp (which is not matched) */

 static void
 expect (FILE *fp)
 {
   int fromlog;
   int fromgdb;

   if ((fromlog = logchar (fp)) != ' ')
     {
       sync_error (fp, "Sync error during gdb read of leading blank", ' ',
 		  fromlog);
     }
   do
     {
       fromlog = logchar (fp);
       if (fromlog == EOL)
 	break;
       fromgdb = gdbchar (remote_desc_in);
       if (fromgdb < 0)
 	remote_error ("Error during read from gdb");
     }
   while (fromlog == fromgdb);

   if (fromlog != EOL)
     {
       sync_error (fp, "Sync error during read of gdb packet from log", fromlog,
 		  fromgdb);
     }
 }

 /* Play data back to gdb from fp (after skipping leading blank) up until a
    \n is read from fp (which is discarded and not sent to gdb). */

 static void
 play (FILE *fp)
 {
   int fromlog;
   char ch;

   if ((fromlog = logchar (fp)) != ' ')
     {
       sync_error (fp, "Sync error skipping blank during write to gdb", ' ',
 		  fromlog);
     }
   while ((fromlog = logchar (fp)) != EOL)
     {
       ch = fromlog;
       if (write (remote_desc_out, &ch, 1) != 1)
 	remote_error ("Error during write to gdb");
     }
 }

 static void
 gdbreplay_version (void)
 {
   printf ("GNU gdbreplay %s%s\n"
 	  "Copyright (C) 2024 Free Software Foundation, Inc.\n"
 	  "gdbreplay is free software, covered by "
 	  "the GNU General Public License.\n"
 	  "This gdbreplay was configured as \"%s\"\n",
 	  PKGVERSION, version, host_name);
 }

 static void
 gdbreplay_usage (FILE *stream)
 {
   fprintf (stream, "Usage:\tgdbreplay LOGFILE HOST:PORT\n");
   if (REPORT_BUGS_TO[0] && stream == stdout)
     fprintf (stream, "Report bugs to \"%s\".\n", REPORT_BUGS_TO);
 }

 /* Main function.  This is called by the real "main" function,
    wrapped in a TRY_CATCH that handles any uncaught exceptions.  */

 static void ATTRIBUTE_NORETURN
 captured_main (int argc, char *argv[])
 {
   FILE *fp;
   int ch;

   if (argc >= 2 && strcmp (argv[1], "--version") == 0)
     {
       gdbreplay_version ();
       exit (0);
     }
   if (argc >= 2 && strcmp (argv[1], "--help") == 0)
     {
       gdbreplay_usage (stdout);
       exit (0);
     }

   if (argc < 3)
     {
       gdbreplay_usage (stderr);
       exit (1);
     }
   fp = fopen (argv[1], "r");
   if (fp == NULL)
     {
       perror_with_name (argv[1]);
     }
   remote_open (argv[2]);
   while ((ch = logchar (fp)) != EOF)
     {
       switch (ch)
 	{
 	case 'w':
 	  /* data sent from gdb to gdbreplay, accept and match it */
 	  expect (fp);
 	  break;
 	case 'r':
 	  /* data sent from gdbreplay to gdb, play it */
 	  play (fp);
 	  break;
 	case 'c':
 	  /* Command executed by gdb */
 	  while ((ch = logchar (fp)) != EOL);
 	  break;
 	}
     }
   remote_close ();
   exit (0);
 }

 int
 main (int argc, char *argv[])
 {
   try
     {
       captured_main (argc, argv);
     }
   catch (const gdb_exception &exception)
     {
       if (exception.reason == RETURN_ERROR)
 	{
 	  fflush (stdout);
 	  fprintf (stderr, "%s\n", exception.what ());
 	}

       exit (1);
     }

   gdb_assert_not_reached ("captured_main should never return");
 }
	/* Replay a remote debug session logfile for GDB.
	Copyright (C) 1996-2024 Free Software Foundation, Inc.
	Written by Fred Fish (fnf@cygnus.com) from pieces of gdbserver.

	This file is part of GDB.

	This program 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.

	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. If not, see <http://www.gnu.org/licenses/>. */

	#undef PACKAGE
	#undef PACKAGE_NAME
	#undef PACKAGE_VERSION
	#undef PACKAGE_STRING
	#undef PACKAGE_TARNAME

	#include <config.h>
	#include "gdbsupport/version.h"

	#if HAVE_SYS_FILE_H
	#include <sys/file.h>
	#endif
	#if HAVE_SIGNAL_H
	#include <signal.h>
	#endif
	#include <ctype.h>
	#if HAVE_FCNTL_H
	#include <fcntl.h>
	#endif
	#include <unistd.h>
	#ifdef HAVE_NETINET_IN_H
	#include <netinet/in.h>
	#endif
	#ifdef HAVE_SYS_SOCKET_H
	#include <sys/socket.h>
	#endif
	#if HAVE_NETDB_H
	#include <netdb.h>
	#endif
	#if HAVE_NETINET_TCP_H
	#include <netinet/tcp.h>
	#endif

	#if USE_WIN32API
	#include <ws2tcpip.h>
	#endif

	#include "gdbsupport/netstuff.h"
	#include "gdbsupport/rsp-low.h"

	#ifndef HAVE_SOCKLEN_T
	typedef int socklen_t;
	#endif

	/* Sort of a hack... */
	#define EOL (EOF - 1)

	static int remote_desc_in;
	static int remote_desc_out;

	static void
	sync_error (FILE fp, const char desc, int expect, int got)
	{
	fprintf (stderr, "\n%s\n", desc);
	fprintf (stderr, "At logfile offset %ld, expected '0x%x' got '0x%x'\n",
	ftell (fp), expect, got);
	fflush (stderr);
	exit (1);
	}

	static void
	remote_error (const char *desc)
	{
	fprintf (stderr, "\n%s\n", desc);
	fflush (stderr);
	exit (1);
	}

	static void
	remote_close (void)
	{
	#ifdef USE_WIN32API
	gdb_assert (remote_desc_in == remote_desc_out);
	closesocket (remote_desc_in);
	#else
	close (remote_desc_in);
	if (remote_desc_in != remote_desc_out)
	close (remote_desc_out);
	#endif
	}

	/* Open a connection to a remote debugger.
	NAME is the filename used for communication. */

	static void
	remote_open (const char *name)
	{
	#ifndef USE_WIN32API
	if (strcmp (name, "-") == 0)
	{
	remote_desc_in = 0;
	remote_desc_out = 1;
	return;
	}
	#endif

	const char *last_colon = strrchr (name, ':');

	if (last_colon == NULL)
	{
	fprintf (stderr, "%s: Must specify tcp connection as host:addr\n", name);
	fflush (stderr);
	exit (1);
	}

	#ifdef USE_WIN32API
	static int winsock_initialized;
	#endif
	int tmp;
	int tmp_desc;
	struct addrinfo hint;
	struct addrinfo *ainfo;

	memset (&hint, 0, sizeof (hint));
	/* Assume no prefix will be passed, therefore we should use
	AF_UNSPEC. */
	hint.ai_family = AF_UNSPEC;
	hint.ai_socktype = SOCK_STREAM;
	hint.ai_protocol = IPPROTO_TCP;

	parsed_connection_spec parsed = parse_connection_spec (name, &hint);

	if (parsed.port_str.empty ())
	error (_("Missing port on hostname '%s'"), name);

	#ifdef USE_WIN32API
	if (!winsock_initialized)
	{
	WSADATA wsad;

	WSAStartup (MAKEWORD (1, 0), &wsad);
	winsock_initialized = 1;
	}
	#endif

	int r = getaddrinfo (parsed.host_str.c_str (), parsed.port_str.c_str (),
	&hint, &ainfo);

	if (r != 0)
	{
	fprintf (stderr, "%s:%s: cannot resolve name: %s\n",
	parsed.host_str.c_str (), parsed.port_str.c_str (),
	gai_strerror (r));
	fflush (stderr);
	exit (1);
	}

	scoped_free_addrinfo free_ainfo (ainfo);

	struct addrinfo *p;

	for (p = ainfo; p != NULL; p = p->ai_next)
	{
	tmp_desc = socket (p->ai_family, p->ai_socktype, p->ai_protocol);

	if (tmp_desc >= 0)
	break;
	}

	if (p == NULL)
	perror_with_name ("Cannot open socket");

	/* Allow rapid reuse of this port. */
	tmp = 1;
	setsockopt (tmp_desc, SOL_SOCKET, SO_REUSEADDR, (char *) &tmp,
	sizeof (tmp));

	switch (p->ai_family)
	{
	case AF_INET:
	((struct sockaddr_in *) p->ai_addr)->sin_addr.s_addr = INADDR_ANY;
	break;
	case AF_INET6:
	((struct sockaddr_in6 *) p->ai_addr)->sin6_addr = in6addr_any;
	break;
	default:
	fprintf (stderr, "Invalid 'ai_family' %d\n", p->ai_family);
	exit (1);
	}

	if (bind (tmp_desc, p->ai_addr, p->ai_addrlen) != 0)
	perror_with_name ("Can't bind address");

	if (p->ai_socktype == SOCK_DGRAM)
	remote_desc_in = tmp_desc;
	else
	{
	struct sockaddr_storage sockaddr;
	socklen_t sockaddrsize = sizeof (sockaddr);
	char orig_host[GDB_NI_MAX_ADDR], orig_port[GDB_NI_MAX_PORT];

	if (listen (tmp_desc, 1) != 0)
	perror_with_name ("Can't listen on socket");

	remote_desc_in = accept (tmp_desc, (struct sockaddr *) &sockaddr,
	&sockaddrsize);

	if (remote_desc_in == -1)
	perror_with_name ("Accept failed");

	/* Enable TCP keep alive process. */
	tmp = 1;
	setsockopt (tmp_desc, SOL_SOCKET, SO_KEEPALIVE,
	(char *) &tmp, sizeof (tmp));

	/* Tell TCP not to delay small packets. This greatly speeds up
	interactive response. */
	tmp = 1;
	setsockopt (remote_desc_in, IPPROTO_TCP, TCP_NODELAY,
	(char *) &tmp, sizeof (tmp));

	if (getnameinfo ((struct sockaddr *) &sockaddr, sockaddrsize,
	orig_host, sizeof (orig_host),
	orig_port, sizeof (orig_port),
	NI_NUMERICHOST \| NI_NUMERICSERV) == 0)
	{
	fprintf (stderr, "Remote debugging from host %s, port %s\n",
	orig_host, orig_port);
	fflush (stderr);
	}

	#ifndef USE_WIN32API
	close (tmp_desc); /* No longer need this */

	signal (SIGPIPE, SIG_IGN); /* If we don't do this, then
	gdbreplay simply exits when
	the remote side dies. */
	#else
	closesocket (tmp_desc); /* No longer need this */
	#endif
	}

	#if defined(F_SETFL) && defined (FASYNC)
	fcntl (remote_desc_in, F_SETFL, FASYNC);
	#endif
	remote_desc_out = remote_desc_in;

	fprintf (stderr, "Replay logfile using %s\n", name);
	fflush (stderr);
	}

	static int
	logchar (FILE *fp)
	{
	int ch;
	int ch2;

	ch = fgetc (fp);
	if (ch != '\r')
	{
	fputc (ch, stderr);
	fflush (stderr);
	}
	switch (ch)
	{
	/* Treat \r\n as a newline. */
	case '\r':
	ch = fgetc (fp);
	if (ch == '\n')
	ch = EOL;
	else
	{
	ungetc (ch, fp);
	ch = '\r';
	}
	fputc (ch == EOL ? '\n' : '\r', stderr);
	fflush (stderr);
	break;
	case '\n':
	ch = EOL;
	break;
	case '\\':
	ch = fgetc (fp);
	fputc (ch, stderr);
	fflush (stderr);
	switch (ch)
	{
	case '\\':
	break;
	case 'b':
	ch = '\b';
	break;
	case 'f':
	ch = '\f';
	break;
	case 'n':
	ch = '\n';
	break;
	case 'r':
	ch = '\r';
	break;
	case 't':
	ch = '\t';
	break;
	case 'v':
	ch = '\v';
	break;
	case 'x':
	ch2 = fgetc (fp);
	fputc (ch2, stderr);
	fflush (stderr);
	ch = fromhex (ch2) << 4;
	ch2 = fgetc (fp);
	fputc (ch2, stderr);
	fflush (stderr);
	ch \|= fromhex (ch2);
	break;
	default:
	/* Treat any other char as just itself */
	break;
	}
	default:
	break;
	}
	return (ch);
	}

	static int
	gdbchar (int desc)
	{
	unsigned char fromgdb;

	if (read (desc, &fromgdb, 1) != 1)
	return -1;
	else
	return fromgdb;
	}

	/* Accept input from gdb and match with chars from fp (after skipping one
	blank) up until a \n is read from fp (which is not matched) */

	static void
	expect (FILE *fp)
	{
	int fromlog;
	int fromgdb;

	if ((fromlog = logchar (fp)) != ' ')
	{
	sync_error (fp, "Sync error during gdb read of leading blank", ' ',
	fromlog);
	}
	do
	{
	fromlog = logchar (fp);
	if (fromlog == EOL)
	break;
	fromgdb = gdbchar (remote_desc_in);
	if (fromgdb < 0)
	remote_error ("Error during read from gdb");
	}
	while (fromlog == fromgdb);

	if (fromlog != EOL)
	{
	sync_error (fp, "Sync error during read of gdb packet from log", fromlog,
	fromgdb);
	}
	}

	/* Play data back to gdb from fp (after skipping leading blank) up until a
	\n is read from fp (which is discarded and not sent to gdb). */

	static void
	play (FILE *fp)
	{
	int fromlog;
	char ch;

	if ((fromlog = logchar (fp)) != ' ')
	{
	sync_error (fp, "Sync error skipping blank during write to gdb", ' ',
	fromlog);
	}
	while ((fromlog = logchar (fp)) != EOL)
	{
	ch = fromlog;
	if (write (remote_desc_out, &ch, 1) != 1)
	remote_error ("Error during write to gdb");
	}
	}

	static void
	gdbreplay_version (void)
	{
	printf ("GNU gdbreplay %s%s\n"
	"Copyright (C) 2024 Free Software Foundation, Inc.\n"
	"gdbreplay is free software, covered by "
	"the GNU General Public License.\n"
	"This gdbreplay was configured as \"%s\"\n",
	PKGVERSION, version, host_name);
	}

	static void
	gdbreplay_usage (FILE *stream)
	{
	fprintf (stream, "Usage:\tgdbreplay LOGFILE HOST:PORT\n");
	if (REPORT_BUGS_TO[0] && stream == stdout)
	fprintf (stream, "Report bugs to \"%s\".\n", REPORT_BUGS_TO);
	}

	/* Main function. This is called by the real "main" function,
	wrapped in a TRY_CATCH that handles any uncaught exceptions. */

	static void ATTRIBUTE_NORETURN
	captured_main (int argc, char *argv[])
	{
	FILE *fp;
	int ch;

	if (argc >= 2 && strcmp (argv[1], "--version") == 0)
	{
	gdbreplay_version ();
	exit (0);
	}
	if (argc >= 2 && strcmp (argv[1], "--help") == 0)
	{
	gdbreplay_usage (stdout);
	exit (0);
	}

	if (argc < 3)
	{
	gdbreplay_usage (stderr);
	exit (1);
	}
	fp = fopen (argv[1], "r");
	if (fp == NULL)
	{
	perror_with_name (argv[1]);
	}
	remote_open (argv[2]);
	while ((ch = logchar (fp)) != EOF)
	{
	switch (ch)
	{
	case 'w':
	/* data sent from gdb to gdbreplay, accept and match it */
	expect (fp);
	break;
	case 'r':
	/* data sent from gdbreplay to gdb, play it */
	play (fp);
	break;
	case 'c':
	/* Command executed by gdb */
	while ((ch = logchar (fp)) != EOL);
	break;
	}
	}
	remote_close ();
	exit (0);
	}

	int
	main (int argc, char *argv[])
	{
	try
	{
	captured_main (argc, argv);
	}
	catch (const gdb_exception &exception)
	{
	if (exception.reason == RETURN_ERROR)
	{
	fflush (stdout);
	fprintf (stderr, "%s\n", exception.what ());
	}

	exit (1);
	}

	gdb_assert_not_reached ("captured_main should never return");
	}