gdbserver: set ptrace flags after creating inferiors

Rename target_ops.arch_setup to .post_create_inferior.  In the Linux
hook, continue calling the low arch setup, then also set ptrace flags.
This corrects the possibility of running without flags, demonstrated by
a new test that would fail to catch a fork before.

gdb/gdbserver/ChangeLog:

2015-12-04  Josh Stone  <jistone@redhat.com>

	* target.h (struct target_ops) <arch_setup>: Rename to ...
	(struct target_ops) <post_create_inferior>: ... this.
	(target_arch_setup): Rename to ...
	(target_post_create_inferior): ... this, calling post_create_inferior.
	* server.c (start_inferior): Update target_arch_setup calls to
	target_post_create_inferior.
	* linux-low.c (linux_low_ptrace_options): Forward declare.
	(linux_arch_setup): Update its comment for general use.
	(linux_post_create_inferior): New, run arch_setup and setup ptrace.
	(struct linux_target_ops): Use linux_post_create_inferior.
	* lynx-low.c (struct lynx_target_ops): Update arch_setup stub comment
	to post_create_inferior.
	* nto-low.c (struct nto_target_ops): Likewise.
	* spu-low.c (struct spu_target_ops): Likewise.
	* win32-low.c (struct win32_target_ops): Likewise.

gdb/testsuite/ChangeLog:

2015-12-04  Josh Stone  <jistone@redhat.com>

	* gdb.base/catch-fork-static.exp: New.

2 files changed, 52 insertions, 0 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 97df17a..99bfed8 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-12-04  Josh Stone  <jistone@redhat.com>
+
+	* gdb.base/catch-fork-static.exp: New.
+
 2015-12-03  Yao Qi  <yao.qi@linaro.org>
 
 	* gdb.base/sizeof.c: Don't include stdio.h and
diff --git a/gdb/testsuite/gdb.base/catch-fork-static.exp b/gdb/testsuite/gdb.base/catch-fork-static.exp
new file mode 100644
index 0000000..96570eb
--- /dev/null
+++ b/gdb/testsuite/gdb.base/catch-fork-static.exp
@@ -0,0 +1,48 @@
+# Copyright (C) 2015 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/>.
+
+# Test that "catch fork" works on static executables.
+
+# For instance, on Linux we need PTRACE_O_TRACEFORK set before the program
+# reaches the fork.  GDBserver was only setting flags when it reached the first
+# stop *after* arch_setup.  In a dynamic executable there is often a swbreak in
+# ld.so probes before reaching main, and ptrace flags were set then.  But a
+# static executable would just keep running and never catch the fork.
+
+if { [is_remote target] || ![isnative] } then {
+    continue
+}
+
+# Until "catch fork" is implemented on other targets...
+#
+if { ![istarget "hppa*-hp-hpux*"] && ![istarget "*-*-linux*"]
+     && ![istarget "*-*-openbsd*"] } then {
+    continue
+}
+
+# Reusing foll-fork.c since it's a simple forking program.
+standard_testfile foll-fork.c
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} $srcfile \
+      {additional_flags=-static}] } {
+    return -1
+}
+
+gdb_test "catch fork" "Catchpoint \[0-9\]* \\(fork\\)"
+
+gdb_run_cmd
+gdb_test "" \
+    "Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
+    "run to fork"