Re: [PATCH v2 2/6] Share parts of gdb/terminal.h with gdbserver

Sergio Durigan Junior
2017-02-07T22:39:46Z

Hey Luis,

Thanks for the review. Comments below.

On Wednesday, February 01 2017, Luis Machado wrote:

> On 01/18/2017 09:36 AM, Sergio Durigan Junior wrote:
>> As part of the bigger work of sharing fork_inferior with gdbserver,
>> some parts of gdb/terminal.h also needed to be moved to a common
>> place. These parts are:
>>
>> - The code responsible for determining some terminal-based define's
>> based on available features;
>>
>> - job control;
>>
>> - terminal-related functions needed by fork_inferior;
>>
>> gdb/ChangeLog:
>> 2017-01-17 Sergio Durigan Junior <sergiodj@redhat.com>
>>
>> * Makefile.in (HFILES_NO_SRCDIR): Add "common/common-terminal.h".
>> * common/common-terminal.h: New file, with parts of "terminal.h".
>> * terminal.h: Move terminal-related defines to
>> "common/common-terminal.h". Include "common/common-terminal.h".
>> (new_tty_prefork): Move to "common/common-terminal.h".
>> (new_tty): Likewise.
>> (new_tty_postfork): Likewise.
>> (job_control): Likewise.
>> (create_tty_session): Likewise.
>> (gdb_setpgid): Likewise.
>> * utils.c: Include "terminal.h".
>>
>> gdb/gdbserver/ChangeLog:
>> 2016-12-22 Sergio Durigan Junior <sergiodj@redhat.com>
>>
>> * terminal.c: New file.
>> ---
>> gdb/Makefile.in | 1 +
>> gdb/common/common-terminal.h | 119 +++++++++++++++++++++++++++++++++++++++++++
>> gdb/gdbserver/terminal.c | 88 ++++++++++++++++++++++++++++++++
>> gdb/terminal.h | 73 +-------------------------
>> gdb/utils.c | 1 +
>> 5 files changed, 210 insertions(+), 72 deletions(-)
>> create mode 100644 gdb/common/common-terminal.h
>> create mode 100644 gdb/gdbserver/terminal.c
>>
>> diff --git a/gdb/Makefile.in b/gdb/Makefile.in
>> index 3f19818..c05d456 100644
>> --- a/gdb/Makefile.in
>> +++ b/gdb/Makefile.in
>> @@ -1469,6 +1469,7 @@ HFILES_NO_SRCDIR = \
>> common/common-regcache.h \
>> common/common-types.h \
>> common/common-utils.h \
>> + common/common-terminal.h \
>> common/errors.h \
>> common/environ.h \
>> common/fileio.h \
>> diff --git a/gdb/common/common-terminal.h b/gdb/common/common-terminal.h
>> new file mode 100644
>> index 0000000..f7ab96a
>> --- /dev/null
>> +++ b/gdb/common/common-terminal.h
>> @@ -0,0 +1,119 @@
>> +/* Common terminal interface definitions for GDB and gdbserver.
>> + Copyright (C) 1986-2017 Free Software Foundation, Inc.
>> +
>> + 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/>. */
>> +
>> +#ifndef COMMON_TERMINAL_H
>> +#define COMMON_TERMINAL_H
>> +
>> +/* If we're using autoconf, it will define HAVE_TERMIOS_H,
>> + HAVE_TERMIO_H and HAVE_SGTTY_H for us. One day we can rewrite
>> + ser-unix.c and inflow.c to inspect those names instead of
>> + HAVE_TERMIOS, HAVE_TERMIO and the implicit HAVE_SGTTY (when neither
>> + HAVE_TERMIOS or HAVE_TERMIO is set). Until then, make sure that
>> + nothing has already defined the one of the names, and do the right
>> + thing. */
>> +
>> +#if !defined (HAVE_TERMIOS) && !defined(HAVE_TERMIO) && !defined(HAVE_SGTTY)
>> +#if defined(HAVE_TERMIOS_H)
>> +#define HAVE_TERMIOS
>> +#else /* ! defined (HAVE_TERMIOS_H) */
>> +#if defined(HAVE_TERMIO_H)
>> +#define HAVE_TERMIO
>> +#else /* ! defined (HAVE_TERMIO_H) */
>> +#if defined(HAVE_SGTTY_H)
>> +#define HAVE_SGTTY
>> +#endif /* ! defined (HAVE_SGTTY_H) */
>> +#endif /* ! defined (HAVE_TERMIO_H) */
>> +#endif /* ! defined (HAVE_TERMIOS_H) */
>> +#endif /* !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) &&
>> + !defined (HAVE_SGTTY) */
>> +
>> +#if defined(HAVE_TERMIOS)
>> +#include <termios.h>
>> +#endif
>> +
>> +#if !defined(_WIN32) && !defined (HAVE_TERMIOS)
>> +
>> +/* Define a common set of macros -- BSD based -- and redefine whatever
>> + the system offers to make it look like that. FIXME: serial.h and
>> + ser-*.c deal with this in a much cleaner fashion; as soon as stuff
>> + is converted to use them, can get rid of this crap. */
>> +
>> +#ifdef HAVE_TERMIO
>> +
>> +#include <termio.h>
>> +
>> +#undef TIOCGETP
>> +#define TIOCGETP TCGETA
>> +#undef TIOCSETN
>> +#define TIOCSETN TCSETA
>> +#undef TIOCSETP
>> +#define TIOCSETP TCSETAF
>> +#define TERMINAL struct termio
>> +
>> +#else /* sgtty */
>> +
>> +#include <fcntl.h>
>> +#include <sgtty.h>
>> +#include <sys/ioctl.h>
>> +#define TERMINAL struct sgttyb
>> +
>> +#endif /* sgtty */
>> +#endif
>> +
>> +#include <sys/types.h>
>> +
>> +/* Do we have job control? Can be assumed to always be the same
>> + within a given run of GDB. Use in gdb/inflow.c and
>> + common/common-inflow.c. */
>> +extern int job_control;
>> +
>> +extern void new_tty (void);
>> +
>> +/* NEW_TTY_PREFORK is called before forking a new child process,
>> + so we can record the state of ttys in the child to be formed.
>> + TTYNAME is null if we are to share the terminal with gdb;
>
> This is still referencing only gdb, but the code is now shared with
> gdbserver as well.
>
>> + or points to a string containing the name of the desired tty.
>> +
>> + NEW_TTY is called in new child processes under Unix, which will
>> + become debugger target processes. This actually switches to
>> + the terminal specified in the NEW_TTY_PREFORK call. */
>> +extern void new_tty_prefork (const char *ttyname);
>> +
>> +/* NEW_TTY_POSTFORK is called after forking a new child process, and
>> + adding it to the inferior table, to store the TTYNAME being used by
>> + the child, or null if it sharing the terminal with gdb. */
>
> Here as well.
>
>> +extern void new_tty_postfork (void);
>> +
>> +/* Create a new session if the inferior will run in a different tty.
>> + A session is UNIX's way of grouping processes that share a controlling
>> + terminal, so a new one is needed if the inferior terminal will be
>> + different from GDB's.
>
> And here.

These are actually right (for now, at least), since they are just used
by GDB and their gdbserver counterpart are just placeholders. I will
expand the comment to mention that.

>> +
>> + Returns the session id of the new session, 0 if no session was created
>> + or -1 if an error occurred. */
>> +extern pid_t create_tty_session (void);
>> +
>> +/* Set the process group of the caller to its own pid, or do nothing
>> + if we lack job control. */
>> +extern int gdb_setpgid (void);
>> +
>> +/* Determine whether we have job control, and set variable JOB_CONTROL
>> + accordingly. */
>> +extern void have_job_control (void);
>> +
>> +#endif /* ! COMMON_TERMINAL_H */
>> diff --git a/gdb/gdbserver/terminal.c b/gdb/gdbserver/terminal.c
>> new file mode 100644
>> index 0000000..42ac651
>> --- /dev/null
>> +++ b/gdb/gdbserver/terminal.c
>> @@ -0,0 +1,88 @@
>> +/* Terminal interface definitions for the GDB remote server.
>> + Copyright (C) 2016-2017 Free Software Foundation, Inc.
>> +
>> + 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/>. */
>> +
>> +#include "server.h"
>> +#include "common-terminal.h"
>> +
>> +/* See common/common-terminal.h. */
>> +
>> +void
>> +new_tty (void)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> +}
>> +
>> +/* See common/common-terminal.h. */
>> +
>> +void
>> +new_tty_prefork (const char *ttyname)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> +}
>> +
>> +/* See common/common-terminal.h. */
>> +
>> +void
>> +new_tty_postfork (void)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> +}
>> +
>> +/* See common/common-terminal.h. */
>> +
>> +pid_t
>> +create_tty_session (void)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> + return (pid_t) 1;
>> +}
>> +
>> +/* See common/common-inferior.h. */
>> +
>> +void
>> +set_inferior_io_terminal (const char *terminal_name)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> +}
>> +
>> +/* See common/common-inferior.h. */
>> +
>> +const char *
>> +get_inferior_io_terminal (void)
>> +{
>> + /* Placeholder needed by fork_inferior. For now, this function is
>> + not needed nor useful to have on gdbserver. When/If we properly
>> + handle terminal modes, we can revisit and implement the needed
>> + support. */
>> + return NULL;
>> +}
>> diff --git a/gdb/terminal.h b/gdb/terminal.h
>> index d8691b2..8139319 100644
>> --- a/gdb/terminal.h
>> +++ b/gdb/terminal.h
>> @@ -19,83 +19,12 @@
>> #if !defined (TERMINAL_H)
>> #define TERMINAL_H 1
>>
>> -
>> -/* If we're using autoconf, it will define HAVE_TERMIOS_H,
>> - HAVE_TERMIO_H and HAVE_SGTTY_H for us. One day we can rewrite
>> - ser-unix.c and inflow.c to inspect those names instead of
>> - HAVE_TERMIOS, HAVE_TERMIO and the implicit HAVE_SGTTY (when neither
>> - HAVE_TERMIOS or HAVE_TERMIO is set). Until then, make sure that
>> - nothing has already defined the one of the names, and do the right
>> - thing. */
>> -
>> -#if !defined (HAVE_TERMIOS) && !defined(HAVE_TERMIO) && !defined(HAVE_SGTTY)
>> -#if defined(HAVE_TERMIOS_H)
>> -#define HAVE_TERMIOS
>> -#else /* ! defined (HAVE_TERMIOS_H) */
>> -#if defined(HAVE_TERMIO_H)
>> -#define HAVE_TERMIO
>> -#else /* ! defined (HAVE_TERMIO_H) */
>> -#if defined(HAVE_SGTTY_H)
>> -#define HAVE_SGTTY
>> -#endif /* ! defined (HAVE_SGTTY_H) */
>> -#endif /* ! defined (HAVE_TERMIO_H) */
>> -#endif /* ! defined (HAVE_TERMIOS_H) */
>> -#endif /* !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) &&
>> - !defined (HAVE_SGTTY) */
>> -
>> -#if defined(HAVE_TERMIOS)
>> -#include <termios.h>
>> -#endif
>> -
>> -#if !defined(_WIN32) && !defined (HAVE_TERMIOS)
>> -
>> -/* Define a common set of macros -- BSD based -- and redefine whatever
>> - the system offers to make it look like that. FIXME: serial.h and
>> - ser-*.c deal with this in a much cleaner fashion; as soon as stuff
>> - is converted to use them, can get rid of this crap. */
>> -
>> -#ifdef HAVE_TERMIO
>> -
>> -#include <termio.h>
>> -
>> -#undef TIOCGETP
>> -#define TIOCGETP TCGETA
>> -#undef TIOCSETN
>> -#define TIOCSETN TCSETA
>> -#undef TIOCSETP
>> -#define TIOCSETP TCSETAF
>> -#define TERMINAL struct termio
>> -
>> -#else /* sgtty */
>> -
>> -#include <fcntl.h>
>> -#include <sgtty.h>
>> -#include <sys/ioctl.h>
>> -#define TERMINAL struct sgttyb
>> -
>> -#endif /* sgtty */
>> -#endif
>> +#include "common-terminal.h"
>>
>> struct inferior;
>>
>> -extern void new_tty_prefork (const char *);
>> -
>> -extern void new_tty (void);
>> -
>> -extern void new_tty_postfork (void);
>> -
>> extern void copy_terminal_info (struct inferior *to, struct inferior *from);
>>
>> -/* Do we have job control? Can be assumed to always be the same within
>> - a given run of GDB. In inflow.c. */
>> -extern int job_control;
>> -
>> -extern pid_t create_tty_session (void);
>> -
>> -/* Set the process group of the caller to its own pid, or do nothing if
>> - we lack job control. */
>> -extern int gdb_setpgid (void);
>> -
>> /* Set up a serial structure describing standard input. In inflow.c. */
>> extern void initialize_stdin_serial (void);
>>
>> diff --git a/gdb/utils.c b/gdb/utils.c
>> index f142ffe..4993145 100644
>> --- a/gdb/utils.c
>> +++ b/gdb/utils.c
>> @@ -53,6 +53,7 @@
>> #include "top.h"
>> #include "main.h"
>> #include "solist.h"
>> +#include "terminal.h"
>>
>> #include "inferior.h" /* for signed_pointer_to_address */
>>
>>
>

Thanks,

--
Sergio
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