Re: [PATCH 3/6] Share parts of gdb/inflow.c with gdbserver

Sergio Durigan Junior
2017-01-03T21:16:23Z

Thanks for the review.

Comments below.

On Monday, December 26 2016, Luis Machado wrote:

> On 12/22/2016 09:39 PM, Sergio Durigan Junior wrote:
>> After sharing parts of gdb/terminal.h, it is also needed to share the
>> two functions on gdb/inflow.c that are going to be needed by the
>> fork_inferior sharing. They are 'gdb_setpgid' and the new
>> 'have_job_control'.
>>
>> gdb/ChangeLog:
>> 2016-12-22 Sergio Durigan Junior <sergiodj@redhat.com>
>>
>> * Makefile.in (SFILES): Add "common/common-inflow.c".
>> (COMMON_OBS): Add "common/common-inflow.o".
>> * common/common-inflow.c: New file, with contents from
>> "gdb/inflow.c".
>> * inflow.c (gdb_setpgid): Move to "common/common-inflow.c".
>> (_initialize_inflow): Move setting of "job_control" to a specific
>> function on "common/common-inflow.c".
>> * utils.c (job_control): Delete.
>>
>> gdb/gdbserver/ChangeLog:
>> 2016-12-22 Sergio Durigan Junior <sergiodj@redhat.com>
>>
>> * Makefile.in: Add rule for "common-inflow.o".
>> (SFILE): Add "common/common-inflow.c".
>> (OBS): Add "common-inflow.o".
>> ---
>> gdb/Makefile.in | 2 +
>> gdb/common/common-inflow.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++
>> gdb/gdbserver/Makefile.in | 5 +++
>> gdb/inflow.c | 63 +-------------------------------
>> gdb/utils.c | 4 --
>> 5 files changed, 100 insertions(+), 65 deletions(-)
>> create mode 100644 gdb/common/common-inflow.c
>>
>> diff --git a/gdb/Makefile.in b/gdb/Makefile.in
>> index 51c0f73..8372b4a 100644
>> --- a/gdb/Makefile.in
>> +++ b/gdb/Makefile.in
>> @@ -1195,6 +1195,7 @@ SFILES = \
>> common/fileio.c \
>> common/filestuff.c \
>> common/format.c \
>> + common/common-inflow.c \
>> common/gdb_vecs.c \
>> common/new-op.c \
>> common/print-utils.c \
>> @@ -1622,6 +1623,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
>> common-agent.o \
>> common-debug.o \
>> common-exceptions.o \
>> + common-inflow.o \
>> common-regcache.o \
>> common-utils.o \
>> complaints.o \
>> diff --git a/gdb/common/common-inflow.c b/gdb/common/common-inflow.c
>> new file mode 100644
>> index 0000000..595eb51
>> --- /dev/null
>> +++ b/gdb/common/common-inflow.c
>> @@ -0,0 +1,91 @@
>> +/* Low level interface to ptrace, for GDB when running under Unix.
>> + Copyright (C) 1986-2016 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 "common-defs.h"
>> +#include "common-terminal.h"
>> +
>> +/* Nonzero if we have job control. */
>> +
>
> Spurious newline?

Nope:

https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Empty_line_between_subprogram_description_and_the_subprogram_implementation

>> +int job_control;
>> +
>> +/* This is here because this is where we figure out whether we (probably)
>> + have job control. Just using job_control only does part of it because
>> + setpgid or setpgrp might not exist on a system without job control.
>> + It might be considered misplaced (on the other hand, process groups and
>> + job control are closely related to ttys).
>> +
>> + For a more clean implementation, in libiberty, put a setpgid which merely
>> + calls setpgrp and a setpgrp which does nothing (any system with job control
>> + will have one or the other). */
>
> newline between comment and function.

This is OK:

https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Empty_line_between_subprogram_description_and_the_subprogram_implementation

>> +int
>> +gdb_setpgid (void)
>> +{
>> + int retval = 0;
>> +
>> + if (job_control)
>> + {
>> +#if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
>> +#ifdef HAVE_SETPGID
>> + /* The call setpgid (0, 0) is supposed to work and mean the same
>> + thing as this, but on Ultrix 4.2A it fails with EPERM (and
>> + setpgid (getpid (), getpid ()) succeeds). */
>> + retval = setpgid (getpid (), getpid ());
>> +#else
>> +#ifdef HAVE_SETPGRP
>> +#ifdef SETPGRP_VOID
>> + retval = setpgrp ();
>> +#else
>> + retval = setpgrp (getpid (), getpid ());
>> +#endif
>> +#endif /* HAVE_SETPGRP */
>> +#endif /* HAVE_SETPGID */
>> +#endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
>> + }
>> +
>> + return retval;
>> +}
>> +
>> +/* See common/common-terminal.h. */
>> +
>> +void
>> +have_job_control (void)
>> +{
>> + /* OK, figure out whether we have job control. If neither termios nor
>> + sgtty (i.e. termio or go32), leave job_control 0. */
>> +#if defined (HAVE_TERMIOS)
>> + /* Do all systems with termios have the POSIX way of identifying job
>> + control? I hope so. */
>> +#ifdef _POSIX_JOB_CONTROL
>> + job_control = 1;
>> +#else
>> +#ifdef _SC_JOB_CONTROL
>> + job_control = sysconf (_SC_JOB_CONTROL);
>> +#else
>> + job_control = 0; /* Have to assume the worst. */
>> +#endif /* _SC_JOB_CONTROL */
>> +#endif /* _POSIX_JOB_CONTROL */
>> +#endif /* HAVE_TERMIOS */
>> +
>> +#ifdef HAVE_SGTTY
>> +#ifdef TIOCGPGRP
>> + job_control = 1;
>> +#else
>> + job_control = 0;
>> +#endif /* TIOCGPGRP */
>> +#endif /* sgtty */
>> +}
>> diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
>> index fe40842..2add910 100644
>> --- a/gdb/gdbserver/Makefile.in
>> +++ b/gdb/gdbserver/Makefile.in
>> @@ -204,6 +204,7 @@ SFILES = \
>> $(srcdir)/common/environ.c \
>> $(srcdir)/common/fileio.c \
>> $(srcdir)/common/filestuff.c \
>> + $(srcdir)/common/common-inflow.c \
>> $(srcdir)/common/gdb_vecs.c \
>> $(srcdir)/common/new-op.c \
>> $(srcdir)/common/print-utils.c \
>> @@ -234,6 +235,7 @@ OBS = \
>> cleanups.o \
>> common-debug.o \
>> common-exceptions.o \
>> + common-inflow.o \
>> common-regcache.o \
>> common-utils.o \
>> debug.o \
>> @@ -770,6 +772,9 @@ format.o: ../common/format.c
>> filestuff.o: ../common/filestuff.c
>> $(COMPILE) $<
>> $(POSTCOMPILE)
>> +common-inflow.o: ../common/common-inflow.c
>> + $(COMPILE) $<
>> + $(POSTCOMPILE)
>> agent.o: ../common/agent.c
>> $(COMPILE) $<
>> $(POSTCOMPILE)
>> diff --git a/gdb/inflow.c b/gdb/inflow.c
>> index 5b55cec..80909ea 100644
>> --- a/gdb/inflow.c
>> +++ b/gdb/inflow.c
>> @@ -803,43 +803,6 @@ create_tty_session (void)
>> #endif /* HAVE_SETSID */
>> }
>>
>> -/* This is here because this is where we figure out whether we (probably)
>> - have job control. Just using job_control only does part of it because
>> - setpgid or setpgrp might not exist on a system without job control.
>> - It might be considered misplaced (on the other hand, process groups and
>> - job control are closely related to ttys).
>> -
>> - For a more clean implementation, in libiberty, put a setpgid which merely
>> - calls setpgrp and a setpgrp which does nothing (any system with job control
>> - will have one or the other). */
>> -int
>> -gdb_setpgid (void)
>> -{
>> - int retval = 0;
>> -
>> - if (job_control)
>> - {
>> -#if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
>> -#ifdef HAVE_SETPGID
>> - /* The call setpgid (0, 0) is supposed to work and mean the same
>> - thing as this, but on Ultrix 4.2A it fails with EPERM (and
>> - setpgid (getpid (), getpid ()) succeeds). */
>> - retval = setpgid (getpid (), getpid ());
>> -#else
>> -#ifdef HAVE_SETPGRP
>> -#ifdef SETPGRP_VOID
>> - retval = setpgrp ();
>> -#else
>> - retval = setpgrp (getpid (), getpid ());
>> -#endif
>> -#endif /* HAVE_SETPGRP */
>> -#endif /* HAVE_SETPGID */
>> -#endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
>> - }
>> -
>> - return retval;
>> -}
>> -
>> /* Get all the current tty settings (including whether we have a
>> tty at all!). We can't do this in _initialize_inflow because
>> serial_fdopen() won't work until the serial_ops_list is
>> @@ -860,30 +823,8 @@ _initialize_inflow (void)
>>
>> terminal_is_ours = 1;
>>
>> - /* OK, figure out whether we have job control. If neither termios nor
>> - sgtty (i.e. termio or go32), leave job_control 0. */
>> -
>> -#if defined (HAVE_TERMIOS)
>> - /* Do all systems with termios have the POSIX way of identifying job
>> - control? I hope so. */
>> -#ifdef _POSIX_JOB_CONTROL
>> - job_control = 1;
>> -#else
>> -#ifdef _SC_JOB_CONTROL
>> - job_control = sysconf (_SC_JOB_CONTROL);
>> -#else
>> - job_control = 0; /* Have to assume the worst. */
>> -#endif /* _SC_JOB_CONTROL */
>> -#endif /* _POSIX_JOB_CONTROL */
>> -#endif /* HAVE_TERMIOS */
>> -
>> -#ifdef HAVE_SGTTY
>> -#ifdef TIOCGPGRP
>> - job_control = 1;
>> -#else
>> - job_control = 0;
>> -#endif /* TIOCGPGRP */
>> -#endif /* sgtty */
>> + /* OK, figure out whether we have job control. */
>> + have_job_control ();
>>
>> observer_attach_inferior_exit (inflow_inferior_exit);
>>
>> diff --git a/gdb/utils.c b/gdb/utils.c
>> index bc1dfe5..6bf3716 100644
>> --- a/gdb/utils.c
>> +++ b/gdb/utils.c
>> @@ -103,10 +103,6 @@ static std::chrono::steady_clock::duration prompt_for_continue_wait_time;
>>
>> static int debug_timestamp = 0;
>>
>> -/* Nonzero if we have job control. */
>> -
>> -int job_control;
>> -
>> /* Nonzero means that strings with character values >0x7F should be printed
>> as octal escapes. Zero means just print the value (e.g. it's an
>> international character, and the terminal or window can cope.) */
>>
>
> Otherwise looks fine.
>

--
Sergio
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