Re: RFA: fix gdb_assert caused by 'catch signal ...' and fork

[Philippe Waroquiers <philippe.waroquiers@skynet.be>]

On Fri, 2013-05-10 at 18:20 +0100, Pedro Alves wrote:
> Hi Philippe,
> 
> (Please mark newer posts/revisions of patches in new threads
> with v2, v3, etc. in the subject line.)
Hello,
Sorry for the slow update after the fast review.
Here is an updated v3 patch, fixing the review comments.

> Write only "2013" when we only have a single year.
> But, if  the file is based on another existing file, we should
> preserve the existing file's copyright years in the new file.
These files were based on a previous files, so restored 2012-2013.


> > +      (void) wait(NULL);
> Missing space before parens.  (do you really need the cast?)
space added.
I added the cast to explicitely show that the return value is ignored.
I might instead not ignore it if you think this is needed/better.

I also added a comment in breakpoint.c, to explain why
the bp_loc_other locations are not removed.

Ok to apply ?

Philippe

Index: gdb/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.15563
diff -u -p -r1.15563 ChangeLog
--- gdb/ChangeLog	16 May 2013 07:39:42 -0000	1.15563
+++ gdb/ChangeLog	16 May 2013 20:19:10 -0000
@@ -1,3 +1,8 @@
+2013-05-16  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* breakpoints.c (detach_breakpoints): Do not
+	detach breakpoints locations with loc_type bp_loc_other.
+
 2013-05-16  Joel Brobecker  <brobecker@adacore.com>
 
 	* dwarf2read.c (set_cu_language): Add DW_LANG_UPC handling.
Index: gdb/breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.761
diff -u -p -r1.761 breakpoint.c
--- gdb/breakpoint.c	7 May 2013 17:04:28 -0000	1.761
+++ gdb/breakpoint.c	16 May 2013 20:19:11 -0000
@@ -3537,6 +3537,15 @@ detach_breakpoints (ptid_t ptid)
     if (bl->pspace != inf->pspace)
       continue;
 
+    /* This function must physically remove breakpoints locations
+       from the specified ptid, without modifying the breakpoint
+       package's state.  Locations of type bp_loc_other are only
+       maintained at GDB side.  So, there is no need to remove
+       these bp_loc_other locations.  Moreover, removing these
+       would modify the breakpoint package's state.  */
+    if (bl->loc_type == bp_loc_other)
+      continue;
+
     if (bl->inserted)
       val |= remove_breakpoint_1 (bl, mark_inserted);
   }
Index: gdb/testsuite/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/ChangeLog,v
retrieving revision 1.3661
diff -u -p -r1.3661 ChangeLog
--- gdb/testsuite/ChangeLog	16 May 2013 10:13:33 -0000	1.3661
+++ gdb/testsuite/ChangeLog	16 May 2013 20:19:14 -0000
@@ -1,3 +1,8 @@
+2013-05-16  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* gdb.base/catch-signal-fork.exp: New file.
+	* gdb.base/catch-signal-fork.c: New file.
+
 2013-05-16  Pedro Alves  <palves@redhat.com>
 
 	* gdb.ada/complete.exp (test_gdb_no_completion): Fix typo in
Index: gdb/testsuite/gdb.base/catch-signal-fork.c
===================================================================
RCS file: gdb/testsuite/gdb.base/catch-signal-fork.c
diff -N gdb/testsuite/gdb.base/catch-signal-fork.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/catch-signal-fork.c	16 May 2013 20:19:14 -0000
@@ -0,0 +1,58 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2012-2013 Free Software Foundation, Inc.
+
+   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 <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+void
+do_nothing (void)
+{
+}
+
+void
+handle (int sig)
+{
+  do_nothing (); /* handle marker */
+}
+
+int
+main ()
+{
+  int i;
+  signal (SIGHUP, handle);
+
+  raise (SIGHUP);		/* first HUP */
+
+  signal (SIGCHLD, handle);
+  for (i = 0; i < 3; i++)	/* fork loop */
+    {
+      switch (fork())
+	{
+	case -1:
+	  perror ("fork");
+	  exit (1);
+	case 0:
+	  exit (0);
+	}
+      (void) wait (NULL);
+    }
+
+  raise (SIGHUP);		/* second HUP */
+
+  raise (SIGHUP);		/* third HUP */
+}
+
Index: gdb/testsuite/gdb.base/catch-signal-fork.exp
===================================================================
RCS file: gdb/testsuite/gdb.base/catch-signal-fork.exp
diff -N gdb/testsuite/gdb.base/catch-signal-fork.exp
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/catch-signal-fork.exp	16 May 2013 20:19:14 -0000
@@ -0,0 +1,43 @@
+# Copyright 2012-2013 Free Software Foundation, Inc.
+
+# 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/>.
+
+if [target_info exists gdb,nosignals] {
+    verbose "Skipping catch-signal-fork.exp because of nosignals."
+    continue
+}
+
+standard_testfile
+
+if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
+    return -1
+}
+
+if {![runto_main]} {
+    return -1
+}
+
+# Test "catch signal SIGHUP"
+gdb_test "catch signal SIGHUP" "Catchpoint .*"
+gdb_breakpoint ${srcfile}:[gdb_get_line_number "first HUP"]
+gdb_breakpoint ${srcfile}:[gdb_get_line_number "fork loop"]
+
+gdb_continue_to_breakpoint "first HUP"
+gdb_test "continue" "Catchpoint .*"
+
+# Test interaction with fork.
+# This used to cause a gdb_assert in the code detaching the
+# breakpoints for the child.
+gdb_continue_to_breakpoint "fork loop"
+gdb_test "continue" "Catchpoint .* SIGHUP.*" "got SIGHUP after fork"