[v5,5/5] Implement proper "startup-with-shell" support on gdbserver

diff --git a/gdb/NEWS b/gdb/NEWS
index 29ae40c..485b9dd 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,15 @@ 
 
 *** Changes since GDB 7.12
 
+* On Unix systems, GDBserver now does globbing expansion and variable
+  substitution in inferior command line arguments.
+
+  This is done by starting inferiors using a shell, like GDB does.
+  See "set startup-with-shell" in the user manual for how to disable
+  this from GDB when using "target extended-remote".  When using
+  "target remote", you can disable the startup with shell by using the
+  new "--no-startup-with-shell" GDBserver command line option.
+
 * GDB now supports access to the PKU register on GNU/Linux. The register is
   added by the Memory Protection Keys for Userspace feature which will be
   available in future Intel CPUs.
@@ -403,6 +412,9 @@  show max-value-size
 
 * New remote packets
 
+QStartupWithShell
+  Indicates whether the inferior must be started with a shell or not.
+
 exec stop reason
   Indicates that an exec system call was executed.
 
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 300d78e..01059ca 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -2153,6 +2153,7 @@  This command is available when debugging locally on most targets, excluding
 @sc{djgpp}, Cygwin, MS Windows, and QNX Neutrino.
 
 @kindex set startup-with-shell
+@anchor{set startup-with-shell}
 @item set startup-with-shell
 @itemx set startup-with-shell on
 @itemx set startup-with-shell off
@@ -20811,6 +20812,10 @@  are:
 @tab @code{QDisableRandomization}
 @tab @code{set disable-randomization}
 
+@item @code{startup-with-shell}
+@tab @code{QStartupWithShell}
+@tab @code{set startup-with-shell}
+
 @item @code{conditional-breakpoints-packet}
 @tab @code{Z0 and Z1}
 @tab @code{Support for target-side breakpoint condition evaluation}
@@ -36443,6 +36448,40 @@  by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
 This should only be done on targets that actually support disabling
 address space randomization.
 
+@item QStartupWithShell:@var{value}
+@cindex startup with shell, remote request
+@cindex @samp{QStartupWithShell} packet
+On UNIX-like targets, it is possible to start the inferior using a
+shell program.  This is the default behavior on both @value{GDBN} and
+@command{gdbserver} (@pxref{set startup-with-shell}).  This packet is
+used to inform @command{gdbserver} whether it should start the
+inferior using a shell or not.
+
+If @var{value} is @samp{0}, @command{gdbserver} will not use a shell
+to start the inferior.  If @var{value} is @samp{1},
+@command{gdbserver} will use a shell to start the inferior.  All other
+values are considered an error.
+
+This packet is only available in extended mode (@pxref{extended
+mode}).
+
+Reply:
+@table @samp
+@item OK
+The request succeeded.
+
+@item E @var{nn}
+An error occurred.  The error number @var{nn} is given as hex digits.
+@end table
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response
+(@pxref{qSupported}).  This should only be done on targets that
+actually support starting the inferior using a shell.
+
+Use of this packet is controlled by the @code{set startup-with-shell}
+command; @pxref{set startup-with-shell}.
+
 @item qfThreadInfo
 @itemx qsThreadInfo
 @cindex list active threads, remote request
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 31c6a6e..b9ee471 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -876,6 +876,31 @@  handle_general_set (char *own_buf)
       return;
     }
 
+  if (startswith (own_buf, "QStartupWithShell:"))
+    {
+      char *value = own_buf + strlen ("QStartupWithShell:");
+
+      if (strcmp (value, "1") == 0)
+	startup_with_shell = true;
+      else if (strcmp (value, "0") == 0)
+	startup_with_shell = false;
+      else
+	{
+	  /* Unknown value.  */
+	  fprintf (stderr, "Unknown value to startup-with-shell: %s\n",
+		   own_buf);
+	  write_enn (own_buf);
+	  return;
+	}
+
+      if (remote_debug)
+	debug_printf (_("[Inferior will %s started with shell]"),
+		      startup_with_shell ? "be" : "not be");
+
+      write_ok (own_buf);
+      return;
+    }
+
   /* Otherwise we didn't know what packet it was.  Say we didn't
      understand it.  */
   own_buf[0] = 0;
@@ -2312,7 +2337,7 @@  handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
 	}
 
       sprintf (own_buf,
-	       "PacketSize=%x;QPassSignals+;QProgramSignals+",
+	       "PacketSize=%x;QPassSignals+;QProgramSignals+;QStartupWithShell+",
 	       PBUFSIZ - 1);
 
       if (target_supports_catch_syscall ())
@@ -3419,6 +3444,13 @@  gdbserver_usage (FILE *stream)
 	   "  --no-disable-randomization\n"
 	   "                        Don't disable address space randomization when\n"
 	   "                        starting PROG.\n"
+	   "  --startup-with-shell\n"
+	   "                        Start PROG using a shell.  I.e., execs a shell that\n"
+	   "                        then execs PROG.  (default)\n"
+	   "  --no-startup-with-shell\n"
+	   "                        Exec PROG directly instead of using a shell.\n"
+	   "                        Disables argument globbing and variable substitution\n"
+	   "                        on UNIX-like systems.\n"
 	   "\n"
 	   "Debug options:\n"
 	   "\n"
@@ -3702,6 +3734,10 @@  captured_main (int argc, char *argv[])
 	disable_randomization = 1;
       else if (strcmp (*next_arg, "--no-disable-randomization") == 0)
 	disable_randomization = 0;
+      else if (strcmp (*next_arg, "--startup-with-shell") == 0)
+	startup_with_shell = true;
+      else if (strcmp (*next_arg, "--no-startup-with-shell") == 0)
+	startup_with_shell = false;
       else if (strcmp (*next_arg, "--once") == 0)
 	run_once = 1;
       else
diff --git a/gdb/remote.c b/gdb/remote.c
index 92e3e6e..05fc4ee 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -1428,6 +1428,7 @@  enum {
   PACKET_QPassSignals,
   PACKET_QCatchSyscalls,
   PACKET_QProgramSignals,
+  PACKET_QStartupWithShell,
   PACKET_qCRC,
   PACKET_qSearch_memory,
   PACKET_vAttach,
@@ -4633,6 +4634,8 @@  static const struct protocol_feature remote_protocol_features[] = {
     PACKET_QCatchSyscalls },
   { "QProgramSignals", PACKET_DISABLE, remote_supported_packet,
     PACKET_QProgramSignals },
+  { "QStartupWithShell", PACKET_DISABLE, remote_supported_packet,
+    PACKET_QStartupWithShell },
   { "QStartNoAckMode", PACKET_DISABLE, remote_supported_packet,
     PACKET_QStartNoAckMode },
   { "multiprocess", PACKET_DISABLE, remote_supported_packet,
@@ -9614,6 +9617,20 @@  extended_remote_create_inferior (struct target_ops *ops,
   if (extended_remote_supports_disable_randomization (ops))
     extended_remote_disable_randomization (disable_randomization);
 
+  /* If startup-with-shell is on, we inform gdbserver to start the
+     remote inferior using a shell.  */
+  if (packet_support (PACKET_QStartupWithShell) != PACKET_DISABLE)
+    {
+      xsnprintf (rs->buf, get_remote_packet_size (),
+		 "QStartupWithShell:%d", startup_with_shell ? 1 : 0);
+      putpkt (rs->buf);
+      getpkt (&rs->buf, &rs->buf_size, 0);
+      if (strcmp (rs->buf, "OK") != 0)
+	error (_("\
+Remote replied unexpectedly while setting startup-with-shell: %s"),
+	       rs->buf);
+    }
+
   /* Now restart the remote server.  */
   run_worked = extended_remote_run (args) != -1;
   if (!run_worked)
@@ -14112,6 +14129,9 @@  Show the maximum size of the address (in bits) in a memory packet."), NULL,
   add_packet_config_cmd (&remote_protocol_packets[PACKET_QProgramSignals],
 			 "QProgramSignals", "program-signals", 0);
 
+  add_packet_config_cmd (&remote_protocol_packets[PACKET_QStartupWithShell],
+			 "QStartupWithShell", "startup-with-shell", 0);
+
   add_packet_config_cmd (&remote_protocol_packets[PACKET_qSymbol],
 			 "qSymbol", "symbol-lookup", 0);
 
diff --git a/gdb/testsuite/gdb.base/startup-with-shell.c b/gdb/testsuite/gdb.base/startup-with-shell.c
new file mode 100644
index 0000000..6278447
--- /dev/null
+++ b/gdb/testsuite/gdb.base/startup-with-shell.c
@@ -0,0 +1,29 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2017 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 <stdio.h>
+
+int
+main (int argc, char *argv[])
+{
+  int i;
+
+  for (i = 0; argv[i] != NULL; ++i)
+    printf ("ARG %d = %s\n", i, argv[i]);
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/startup-with-shell.exp b/gdb/testsuite/gdb.base/startup-with-shell.exp
new file mode 100644
index 0000000..1284829
--- /dev/null
+++ b/gdb/testsuite/gdb.base/startup-with-shell.exp
@@ -0,0 +1,79 @@ 
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2017 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/>.
+
+# This test doesn't make sense on native-gdbserver.
+if { [use_gdb_stub] } {
+    untested "not supported"
+    return
+}
+
+standard_testfile
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile debug] } {
+    return -1
+}
+
+set unique_file [standard_output_file "unique-file.unique-extension"]
+
+# Initial setup for simple test (wildcard expansion, variable substitution).
+
+proc initial_setup_simple { startup_with_shell run_args } {
+    global hex decimal binfile unique_file
+
+    clean_restart $binfile
+
+    gdb_test_no_output "set startup-with-shell $startup_with_shell"
+
+    gdb_test_no_output "set args $run_args"
+
+    set test "inferior started"
+    if { [runto_main] } {
+	pass $test
+    } else {
+	fail $test
+    }
+}
+
+## Run the actual tests
+
+with_test_prefix "startup_with_shell = on; run_args = *.unique-extension" {
+    initial_setup_simple "on" "*.unique-extension"
+    gdb_test "print argv\[1\]" "\\\$$decimal = $hex \"unique-file\.unique-extension\"" \
+	"first argument expanded"
+}
+
+with_test_prefix "startup_with_shell = off; run_args = *.unique-extension" {
+    initial_setup_simple "off" "*.unique-extension"
+    gdb_test "print argv\[1\]" "\\\$$decimal = $hex \"\\\*\.unique-extension\"" \
+	"first argument not expanded"
+}
+
+with_test_prefix "startup_with_shell = on; run_args = \$TEST" {
+    set env(TEST) "1234"
+    initial_setup_simple "on" "\$TEST"
+    gdb_test "print argv\[1\]" "\\\$$decimal = $hex \"1234\"" \
+	"testing first argument"
+    unset env(TEST)
+}
+
+with_test_prefix "startup_with_shell = off; run_args = \$TEST" {
+    set env(TEST) "1234"
+    initial_setup_simple "off" "\$TEST"
+    gdb_test "print argv\[1\]" "\\\$$decimal = $hex \"\\\$TEST\"" \
+	"testing first argument"
+    unset env(TEST)
+}