[RFC] Create src/gdb/common, move signals.c there.

[dje at google dot com (Doug Evans)]

Hi.

Some code is shared between gdb and gdbserver, and over time more
code will be shared.  And I think the lack of explicit sharing
is complicating progress.

So I'd like to create a path for further sharing, and am starting
with a modest step to see if there's interest in pursuing this.

This patch does these things:

1) Create src/gdb/common, and adds -I's to $(src)/common to the Makefiles.
2) Pull the duplicate decls of the functions in signals.c out of
   gdb/target.h and gdbserver/server.h and put them in common/gdb_signals.h.
3) Move signals/signals.c to common/signals.c, and cleans up signals.c
   a bit.

I recognize that manually configuring gdbserver and building it apart
from gdb is explicitly supported, and this patch doesn't change this.
[Nor am I suggesting breaking this,
e.g. I'm not proposing creating libcommon.a.]

One thing I would like to have done in this patch is remove the #include's of
defs.h and server.h from signals.c, but that involves making gdb_string.h
work in both gdb and gdbserver.  I think this is a reasonable goal,
(modulo having gdb and gdbserver go to a gnulib version, if that makes sense)
but it requires a bit of effort (e.g. gdb/configure.ac and
gdbserver/configure.ac script hacking and how much of them to make common,
either as duplication or as a separate .m4 file or some such),
and I didn't want to put too much effort into this until there's general
agreement in principle of the path.

Further steps that can be taken:
[whether any particular suggestion is worth it is debatable,
the point here is to enumerate the steps that _could_ be taken,
and no claim is made that this list is complete]

- move version.h to common,
  allowing us to remove the duplication in server.h
- pull the gdb-specific functions out of signals.c,
  allowing us to remove the #ifndef GDBSERVER in signals.c
- maybe(!) move regformats to common, though it's big enough
  and standalone enough that I don't have an opinion on it
- create a common place to put things like ATTR_FORMAT, ATTR_NORETURN, etc.
  (and various other duplication b/w defs.h/server.h),
  allowing us to remove the duplication in defs.h/server.h
- similarily for the duplication b/w gdb_string.h and server.h

WDYT?


2009-02-05  Doug Evans  <dje@google.com>

	* Makefile.in (GDB_CFLAGS): Add -I$(srcdir)/common.
	(init.c): signals/ -> common/.
	(signals.o): Update.
	* target.h (target_signal_to_string,target_signal_to_string)
	(target_signal_from_name,target_signal_to_host_p)
	(target_signal_from_host,target_signal_to_host): Move to ...
	* common/gdb_signals.h: ... here.  New file.

	* gdbserver/Makefile.in (INCLUDE_CFLAGS): Add -I$(srcdir)/../common.
	(server_h): Add gdb_signals.h.
	(signals.o): Update.
	* server.h (target_signal_from_host,target_signal_to_host_p)
	(target_signal_to_host,target_signal_to_name): Moved to gdb_signals.h.

	* common/signals.c: Moved here from signals/signals.c.
	#include gdb_signals.h, remove #include of target.h in gdb case.
	(target_signal_from_command,default_target_signal_to_host)
	(default_target_signal_from_host): Move inside #ifndef GDBSERVER.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.1065
diff -u -p -u -p -r1.1065 Makefile.in
--- Makefile.in	30 Jan 2009 22:14:52 -0000	1.1065
+++ Makefile.in	5 Feb 2009 20:24:15 -0000
@@ -363,7 +363,8 @@ CONFIG_UNINSTALL = @CONFIG_UNINSTALL@
 # your system doesn't have fcntl.h in /usr/include (which is where it
 # should be according to Posix).
 DEFS = @DEFS@
-GDB_CFLAGS = -I. -I$(srcdir) -I$(srcdir)/config -DLOCALEDIR="\"$(localedir)\"" $(DEFS)
+GDB_CFLAGS = -I. -I$(srcdir) -I$(srcdir)/common -I$(srcdir)/config \
+	-DLOCALEDIR="\"$(localedir)\"" $(DEFS)
 
 # MH_CFLAGS, if defined, has host-dependent CFLAGS from the config directory.
 GLOBAL_CFLAGS = $(MH_CFLAGS)
@@ -1029,7 +1030,7 @@ init.c: $(INIT_FILES)
 	    -e '/^[a-z0-9A-Z_]*_[SU].[co]$$/d' \
 	    -e '/[a-z0-9A-Z_]*-exp.tab.[co]$$/d' \
 	    -e 's/\.[co]$$/.c/' \
-	    -e 's,signals\.c,signals/signals\.c,' \
+	    -e 's,signals\.c,common/signals\.c,' \
 	    -e 's|^\([^  /][^     ]*\)|$(srcdir)/\1|g' | \
 	while read f; do \
 	    sed -n -e 's/^_initialize_\([a-z_0-9A-Z]*\).*/\1/p' $$f 2>/dev/null; \
@@ -1736,13 +1737,13 @@ mi-common.o: $(srcdir)/mi/mi-common.c
 	$(POSTCOMPILE)
 
 #
-# gdb/signals/ dependencies
+# gdb/common/ dependencies
 #
 # Need to explicitly specify the compile rule as make will do nothing
 # or try to compile the object file into the sub-directory.
 
-signals.o: $(srcdir)/signals/signals.c
-	$(COMPILE) $(srcdir)/signals/signals.c
+signals.o: $(srcdir)/common/signals.c
+	$(COMPILE) $(srcdir)/common/signals.c
 	$(POSTCOMPILE)
 
 #
Index: target.h
===================================================================
RCS file: /cvs/src/src/gdb/target.h,v
retrieving revision 1.141
diff -u -p -u -p -r1.141 target.h
--- target.h	1 Feb 2009 23:31:03 -0000	1.141
+++ target.h	5 Feb 2009 20:24:15 -0000
@@ -55,6 +55,7 @@ struct regcache;
 #include "dcache.h"
 #include "memattr.h"
 #include "vec.h"
+#include "gdb_signals.h"
 
 enum strata
   {
@@ -176,15 +177,6 @@ enum inferior_event_type
        'step n' like commands.  */
     INF_EXEC_CONTINUE
   };
-
-/* Return the string for a signal.  */
-extern const char *target_signal_to_string (enum target_signal);
-
-/* Return the name (SIGHUP, etc.) for a signal.  */
-extern const char * target_signal_to_name (enum target_signal);
-
-/* Given a name (SIGHUP, etc.), return its signal.  */
-enum target_signal target_signal_from_name (const char *);
 
 /* Target objects which can be transfered using target_read,
    target_write, et cetera.  */
@@ -1307,28 +1299,7 @@ extern int remote_timeout;
 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
 extern void store_waitstatus (struct target_waitstatus *, int);
 
-/* Predicate to target_signal_to_host(). Return non-zero if the enum
-   targ_signal SIGNO has an equivalent ``host'' representation.  */
-/* FIXME: cagney/1999-11-22: The name below was chosen in preference
-   to the shorter target_signal_p() because it is far less ambigious.
-   In this context ``target_signal'' refers to GDB's internal
-   representation of the target's set of signals while ``host signal''
-   refers to the target operating system's signal.  Confused?  */
-
-extern int target_signal_to_host_p (enum target_signal signo);
-
-/* Convert between host signal numbers and enum target_signal's.
-   target_signal_to_host() returns 0 and prints a warning() on GDB's
-   console if SIGNO has no equivalent host representation.  */
-/* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
-   refering to the target operating system's signal numbering.
-   Similarly, ``enum target_signal'' is named incorrectly, ``enum
-   gdb_signal'' would probably be better as it is refering to GDB's
-   internal representation of a target operating system's signal.  */
-
-extern enum target_signal target_signal_from_host (int);
-extern int target_signal_to_host (enum target_signal);
-
+/* These are in common/signals.c, but they're only used by gdb.  */
 extern enum target_signal default_target_signal_from_host (struct gdbarch *,
 							   int);
 extern int default_target_signal_to_host (struct gdbarch *, 
@@ -1336,6 +1307,7 @@ extern int default_target_signal_to_host
 
 /* Convert from a number used in a GDB command to an enum target_signal.  */
 extern enum target_signal target_signal_from_command (int);
+/* End of files in common/signals.c.  */
 
 /* Set the show memory breakpoints mode to show, and installs a cleanup
    to restore it back to the current value.  */
Index: gdbserver/Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
retrieving revision 1.68
diff -u -p -u -p -r1.68 Makefile.in
--- gdbserver/Makefile.in	3 Jan 2009 05:57:56 -0000	1.68
+++ gdbserver/Makefile.in	5 Feb 2009 20:24:15 -0000
@@ -74,7 +74,8 @@ INCLUDE_DEP = $$(INCLUDE_DIR)
 # -I. for config files.
 # -I${srcdir} for our headers.
 # -I$(srcdir)/../regformats for regdef.h.
-INCLUDE_CFLAGS = -I. -I${srcdir} -I$(srcdir)/../regformats -I$(INCLUDE_DIR)
+INCLUDE_CFLAGS = -I. -I${srcdir} -I$(srcdir)/../common \
+	-I$(srcdir)/../regformats -I$(INCLUDE_DIR)
 
 # M{H,T}_CFLAGS, if defined, has host- and target-dependent CFLAGS
 # from the config/ directory.
@@ -263,7 +264,7 @@ regdat_sh = $(srcdir)/../regformats/regd
 regdef_h = $(srcdir)/../regformats/regdef.h
 regcache_h = $(srcdir)/regcache.h
 server_h = $(srcdir)/server.h $(regcache_h) config.h $(srcdir)/target.h \
-		$(srcdir)/mem-break.h
+		$(srcdir)/mem-break.h $(srcdir)/../common/gdb_signals.h
 
 hostio.o: hostio.c $(server_h)
 hostio-errno.o: hostio-errno.c $(server_h)
@@ -278,7 +279,7 @@ thread-db.o: thread-db.c $(server_h) $(g
 utils.o: utils.c $(server_h)
 gdbreplay.o: gdbreplay.c config.h
 
-signals.o: ../signals/signals.c $(server_h)
+signals.o: ../common/signals.c $(server_h)
 	$(CC) -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $< -DGDBSERVER
 
 memmem.o: ../gnulib/memmem.c
Index: gdbserver/server.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
retrieving revision 1.51
diff -u -p -u -p -r1.51 server.h
--- gdbserver/server.h	19 Jan 2009 00:16:46 -0000	1.51
+++ gdbserver/server.h	5 Feb 2009 20:24:15 -0000
@@ -110,7 +110,7 @@ struct dll_info
 
 #include "regcache.h"
 #include "gdb/signals.h"
-
+#include "gdb_signals.h"
 #include "target.h"
 #include "mem-break.h"
 
@@ -265,12 +265,6 @@ void buffer_xml_printf (struct buffer *b
 #define buffer_grow_str0(BUFFER,STRING)                        \
   buffer_grow (BUFFER, STRING, strlen (STRING) + 1)
 
-/* Functions from ``signals.c''.  */
-enum target_signal target_signal_from_host (int hostsig);
-int target_signal_to_host_p (enum target_signal oursig);
-int target_signal_to_host (enum target_signal oursig);
-const char *target_signal_to_name (enum target_signal);
-
 /* Functions from utils.c */
 
 void *xmalloc (size_t) ATTR_MALLOC;



diff -u -p common/server.c
--- signals/signals.c	2009-01-15 14:07:20.000000000 -0800
+++ common/signals.c	2009-02-05 13:15:43.000000000 -0800
@@ -23,7 +23,6 @@
 #include "server.h"
 #else
 #include "defs.h"
-#include "target.h"
 #include "gdb_string.h"
 #endif
 
@@ -31,6 +30,8 @@
 #include <signal.h>
 #endif
 
+#include "gdb_signals.h"
+
 struct gdbarch;
 
 /* Always use __SIGRTMIN if it's available.  SIGRTMIN is the lowest
@@ -807,6 +808,8 @@ target_signal_to_host (enum target_signa
     return targ_signo;
 }
 
+#ifndef GDBSERVER
+
 /* In some circumstances we allow a command to specify a numeric
    signal.  The idea is to keep these circumstances limited so that
    users (and scripts) develop portable habits.  For comparison,
@@ -824,7 +827,6 @@ target_signal_from_command (int num)
 Use \"info signals\" for a list of symbolic signals.");
 }
 
-#ifndef GDBSERVER
 extern initialize_file_ftype _initialize_signals; /* -Wmissing-prototype */
 
 void
@@ -833,7 +835,6 @@ _initialize_signals (void)
   if (strcmp (signals[TARGET_SIGNAL_LAST].string, "TARGET_SIGNAL_MAGIC") != 0)
     internal_error (__FILE__, __LINE__, "failed internal consistency check");
 }
-#endif
 
 int
 default_target_signal_to_host (struct gdbarch *gdbarch, enum target_signal ts)
@@ -846,3 +847,5 @@ default_target_signal_from_host (struct 
 {
   return target_signal_from_host (signo);
 }
+
+#endif /* ! GDBSERVER */



diff -u -p common/gdb_signals.h
--- /dev/null	2007-10-18 09:27:25.000000000 -0700
+++ common/gdb_signals.h	2009-02-05 11:58:47.000000000 -0800
@@ -0,0 +1,56 @@
+/* Target signal translation functions for GDB.
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+   2000, 2001, 2002, 2003, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
+   Contributed by Cygnus Support.
+
+   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_GDB_SIGNALS_H
+#define COMMON_GDB_SIGNALS_H
+
+#include "gdb/signals.h"
+
+/* Predicate to target_signal_to_host(). Return non-zero if the enum
+   targ_signal SIGNO has an equivalent ``host'' representation.  */
+/* FIXME: cagney/1999-11-22: The name below was chosen in preference
+   to the shorter target_signal_p() because it is far less ambigious.
+   In this context ``target_signal'' refers to GDB's internal
+   representation of the target's set of signals while ``host signal''
+   refers to the target operating system's signal.  Confused?  */
+extern int target_signal_to_host_p (enum target_signal signo);
+
+/* Convert between host signal numbers and enum target_signal's.
+   target_signal_to_host() returns 0 and prints a warning() on GDB's
+   console if SIGNO has no equivalent host representation.  */
+/* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
+   refering to the target operating system's signal numbering.
+   Similarly, ``enum target_signal'' is named incorrectly, ``enum
+   gdb_signal'' would probably be better as it is refering to GDB's
+   internal representation of a target operating system's signal.  */
+extern enum target_signal target_signal_from_host (int);
+extern int target_signal_to_host (enum target_signal);
+
+/* Return the string for a signal.  */
+extern const char *target_signal_to_string (enum target_signal);
+
+/* Return the name (SIGHUP, etc.) for a signal.  */
+extern const char *target_signal_to_name (enum target_signal);
+
+/* Given a name (SIGHUP, etc.), return its signal.  */
+enum target_signal target_signal_from_name (const char *);
+
+#endif /* COMMON_GDB_SIGNALS_H */