[PATCH 4/8] PR28392 Add a '--no-escape-args' option for gdb and gdbserver

[Michael Weghorn <m.weghorn@posteo.de>]

This introduces a new '--no-escape-args' option
for gdb and gdbserver.

When the startup-with-shell option is enabled, args
passed directly on 'gdb --args <args>' or
'gdbserver <args>' invocation are by default escaped
so that they are passed to the inferior as passed on
invocation, no globbing or variable substitution happens
when the args are passed to the shell that is
started by the GDB process later.
(For gdbserver, this is the case since
commit bea571ebd78ee29cb94adf648fbcda1e109e1be6,
"Use construct_inferior_arguments which handles special chars".)

Only args set e.g. via 'set args <args>' or
'run <args>' are not escaped.

For the 'gdb --args' case, directly settings unescaped
args on gdb invocation was possible e.g. by using the
"--eval-command='set args <args>'", while this possibility
did not exist for gdbserver.

The new '--no-escape-args' option disables this escaping of
args passed directly on invocation.

For gdbserver, using this new option allows having the behaviour
from before commit bea571ebd78ee29cb94adf648fbcda1e109e1be6,
while keeping the behaviour unified between GDB and GDBserver.

(For more reasoning, s. the discussion in PR28392,
"gdb server no longer supports argument globbing and variable
substitution".)
---
 gdb/infcmd.c        |  4 ++--
 gdb/inferior.h      |  2 +-
 gdb/main.c          |  6 +++++-
 gdbserver/server.cc | 28 ++++++++++++++++++++++++----
 4 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index b55a56c020d..4283f3ba201 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -123,10 +123,10 @@ show_inferior_tty_command (struct ui_file *file, int from_tty,
 }
 
 void
-set_inferior_args_vector (int argc, char **argv)
+set_inferior_args_vector (int argc, char **argv, bool escape_args)
 {
   gdb::array_view<char * const> args (argv, argc);
-  std::string n = construct_inferior_arguments (args);
+  std::string n = construct_inferior_arguments (args, escape_args);
   current_inferior ()->set_args (std::move (n));
 }
 
diff --git a/gdb/inferior.h b/gdb/inferior.h
index e9210b1258d..0896bb1f459 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -204,7 +204,7 @@ extern void post_create_inferior (int from_tty);
 
 extern void attach_command (const char *, int);
 
-extern void set_inferior_args_vector (int, char **);
+extern void set_inferior_args_vector (int, char **, bool escape_args);
 
 extern void registers_info (const char *, int);
 
diff --git a/gdb/main.c b/gdb/main.c
index ca4ccc375dc..2b979d010c1 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -628,6 +628,7 @@ captured_main_1 (struct captured_main_args *context)
 
   static int quiet = 0;
   static int set_args = 0;
+  static int escape_args = 1;
   static int inhibit_home_gdbinit = 0;
 
   /* Pointers to various arguments from command line.  */
@@ -833,6 +834,7 @@ captured_main_1 (struct captured_main_args *context)
       {"statistics", no_argument, 0, OPT_STATISTICS},
       {"write", no_argument, &write_files_1, 1},
       {"args", no_argument, &set_args, 1},
+      {"no-escape-args", no_argument, &escape_args, 0},
       {"l", required_argument, 0, 'l'},
       {"return-child-result", no_argument, &return_child_result, 1},
       {0, no_argument, 0, 0}
@@ -1070,7 +1072,7 @@ captured_main_1 (struct captured_main_args *context)
       symarg = argv[optind];
       execarg = argv[optind];
       ++optind;
-      set_inferior_args_vector (argc - optind, &argv[optind]);
+      set_inferior_args_vector (argc - optind, &argv[optind], escape_args);
     }
   else
     {
@@ -1399,6 +1401,8 @@ This is the GNU debugger.  Usage:\n\n\
   fputs_unfiltered (_("\
 Selection of debuggee and its files:\n\n\
   --args             Arguments after executable-file are passed to inferior.\n\
+  --no-escape-args   Don't escape args passed via '--args' when invoking the\n\
+                     inferior in a shell.\n\
   --core=COREFILE    Analyze the core dump COREFILE.\n\
   --exec=EXECFILE    Use EXECFILE as the executable.\n\
   --pid=PID          Attach to running process PID.\n\
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 3926be19fd1..14bd1af0404 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -3456,10 +3456,20 @@ gdbserver_usage (FILE *stream)
 	   "  --startup-with-shell\n"
 	   "                        Start PROG using a shell.  I.e., execs a shell that\n"
 	   "                        then execs PROG.  (default)\n"
+	   "                        To make use of globbing and variable subsitution for\n"
+	   "                        arguments passed directly on gdbserver invocation,\n"
+	   "                        see the --no-escape-args command line option in\n"
+	   "                        addition\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"
+	   "  --no-escape-args\n"
+	   "                        If PROG is started using a shell (see the\n"
+	   "                        --[no-]startup-with-shell option),\n"
+	   "                        ARGS passed directly on gdbserver invocation are\n"
+	   "                        escaped, so no globbing or variable substitution\n"
+	   "                        happens for those. This option disables escaping, so\n"
+	   "                        globbing and variable substituation in the shell\n"
+	   "                        are done for ARGS on UNIX-like systems.\n"
 	   "\n"
 	   "Debug options:\n"
 	   "\n"
@@ -3689,6 +3699,7 @@ captured_main (int argc, char *argv[])
   volatile int attach = 0;
   int was_running;
   bool selftest = false;
+  bool escape_args = true;
 #if GDB_SELF_TEST
   std::vector<const char *> selftest_filters;
 
@@ -3825,6 +3836,8 @@ captured_main (int argc, char *argv[])
 	startup_with_shell = true;
       else if (strcmp (*next_arg, "--no-startup-with-shell") == 0)
 	startup_with_shell = false;
+      else if (strcmp (*next_arg, "--no-escape-args") == 0)
+        escape_args = false;
       else if (strcmp (*next_arg, "--once") == 0)
 	run_once = true;
       else if (strcmp (*next_arg, "--selftest") == 0)
@@ -3933,8 +3946,15 @@ captured_main (int argc, char *argv[])
       program_path.set (make_unique_xstrdup (next_arg[0]));
       for (i = 1; i < n; i++)
         {
-          std::string escaped_arg = escape_arg_as_necessary (next_arg[i]);
-          program_args.push_back (xstrdup (escaped_arg.c_str ()));
+          if (escape_args)
+            {
+              std::string escaped_arg = escape_arg_as_necessary (next_arg[i]);
+              program_args.push_back (xstrdup (escaped_arg.c_str ()));
+            }
+          else
+            {
+              program_args.push_back (xstrdup (next_arg[i]));
+            }
         }
 
       /* Wait till we are at first instruction in program.  */
-- 
2.33.0