[v3,3/6] Share parts of gdb/inflow.c with gdbserver

Message ID 20170208032257.15443-4-sergiodj@redhat.com
State New, archived
Headers

Commit Message

Sergio Durigan Junior Feb. 8, 2017, 3:22 a.m. UTC
  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:
yyyy-mm-dd  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
	"handle_job_control".
	* utils.c (job_control): Delete.

gdb/gdbserver/ChangeLog:
yyyy-mm-dd  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
  

Comments

Pedro Alves Feb. 15, 2017, 4:01 p.m. UTC | #1
On 02/08/2017 03:22 AM, Sergio Durigan Junior wrote:

> gdb/ChangeLog:
> yyyy-mm-dd  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
> 	"handle_job_control".
> 	* utils.c (job_control): Delete.
> 
> gdb/gdbserver/ChangeLog:
> yyyy-mm-dd  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".


We should take the opportunity to rename the file to something that
makes a more sense wrt to its contents.  "inflow.c" in gdb is
horribly named, I think simply due to code evolution.  It used to
contain, many many years ago the (from the top of the file):

/* Low level interface to ptrace, for GDB when running under Unix.

but everything related to low level ptrace stuff moved away, and
all it was left with was the terminal/job control stuff.

Maybe call it common/job-control.c or maybe something even more
to the point or something like that.

> diff --git a/gdb/common/common-inflow.c b/gdb/common/common-inflow.c
> new file mode 100644
> index 0000000..9871b5e
> --- /dev/null
> +++ b/gdb/common/common-inflow.c
> @@ -0,0 +1,91 @@
> +/* Low level interface to ptrace, for GDB and gdbserver when running under Unix.

Please update this.  The file really has nothing to do with ptrace.

> +
> +#include "common-defs.h"
> +#include "common-terminal.h"
> +
> +/* Nonzero if we have job control.  */
> +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).


This "misplaced" comment could use some updating.  This is no longer
next to the tty stuff.

> +
> +   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

Thanks,
Pedro Alves
  
Sergio Durigan Junior Feb. 16, 2017, 10:06 p.m. UTC | #2
Thanks for the review.  Comments below.

On Wednesday, February 15 2017, Pedro Alves wrote:

> On 02/08/2017 03:22 AM, Sergio Durigan Junior wrote:
>
>> gdb/ChangeLog:
>> yyyy-mm-dd  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
>> 	"handle_job_control".
>> 	* utils.c (job_control): Delete.
>> 
>> gdb/gdbserver/ChangeLog:
>> yyyy-mm-dd  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".
>
>
> We should take the opportunity to rename the file to something that
> makes a more sense wrt to its contents.  "inflow.c" in gdb is
> horribly named, I think simply due to code evolution.  It used to
> contain, many many years ago the (from the top of the file):
>
> /* Low level interface to ptrace, for GDB when running under Unix.
>
> but everything related to low level ptrace stuff moved away, and
> all it was left with was the terminal/job control stuff.
>
> Maybe call it common/job-control.c or maybe something even more
> to the point or something like that.

Good point, I hadn't thought about that.  I renamed the file to
common/job-control.c, because even though it also contains terminal
related stuff, the main purpose of the functions there is to help with
job control.

>> diff --git a/gdb/common/common-inflow.c b/gdb/common/common-inflow.c
>> new file mode 100644
>> index 0000000..9871b5e
>> --- /dev/null
>> +++ b/gdb/common/common-inflow.c
>> @@ -0,0 +1,91 @@
>> +/* Low level interface to ptrace, for GDB and gdbserver when running under Unix.
>
> Please update this.  The file really has nothing to do with ptrace.

Done.

>> +
>> +#include "common-defs.h"
>> +#include "common-terminal.h"
>> +
>> +/* Nonzero if we have job control.  */
>> +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).
>
>
> This "misplaced" comment could use some updating.  This is no longer
> next to the tty stuff.

Done.

>> +
>> +   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

Thanks,
  

Patch

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 6dc80ea..84762c4 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1198,6 +1198,7 @@  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 \
@@ -1626,6 +1627,7 @@  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..9871b5e
--- /dev/null
+++ b/gdb/common/common-inflow.c
@@ -0,0 +1,91 @@ 
+/* Low level interface to ptrace, for GDB and gdbserver when running under Unix.
+   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/>.  */
+
+#include "common-defs.h"
+#include "common-terminal.h"
+
+/* Nonzero if we have job control.  */
+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).  */
+
+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 ef0dc99..74e199b 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 7ffa83a..271278d 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 6cbaf07..c6f2527 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.)  */