gdb/main: execute breakpoint commands for '-iex' and '-ex' commands

Suppose we have the script file below:

  break main
  commands
    print 123
  end
  run

If started with this script file, GDB executes the breakpoint command:

  $ gdb -q -x myscript --args ./test
  Reading symbols from ./test...
  Breakpoint 1 at 0x114e: file test.c, line 2.

  Breakpoint 1, main () at test.c:2
  2         return 0;
  $1 = 123
  (gdb)

However, if we remove the "run" line from the script and pass it with
the '-ex' option instead, the command is not executed:

  $ gdb -q -x myscript_no_run --args ./test
  Reading symbols from ./test...
  Breakpoint 1 at 0x114e: file test.c, line 2.
  Starting program: /path/to/test

  Breakpoint 1, main () at test.c:2
  2         return 0;
  (gdb)

If the user enters a command at this point, the breakpoint command
is executed, yielding weird output:

  $ gdb -q -x myscript_no_run --args ./test
  Reading symbols from ./test...
  Breakpoint 1 at 0x114e: file test.c, line 2.
  Starting program: /path/to/test

  Breakpoint 1, main () at test.c:2
  2         return 0;
  (gdb) print "a"
  $1 = "a"
  $2 = 123

When consuming script files, GDB runs bp actions after executing a
command.  See `command_handler` in event-top.c:

  if (c[0] != '#')
    {
      execute_command (command, ui->instream == ui->stdin_stream);

      /* Do any commands attached to breakpoint we stopped at.  */
      bpstat_do_actions ();
    }

However, for '-ex' commands, `bpstat_do_actions` is not invoked.
Hence, the misaligned output explained above occurs.  To fix the
problem, add a call to `bpstat_do_actions` after executing a command.

gdb/ChangeLog:
2020-12-07  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* main.c (catch_command_errors): Add a flag parameter; invoke
	`bpstat_do_actions` if the flag is set.
	(execute_cmdargs): Update a call to `catch_command_errors`.

gdb/testsuite/ChangeLog:
2020-12-07  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* gdb.base/bp-cmds-run-with-ex.c: New file.
	* gdb.base/bp-cmds-run-with-ex.exp: New file.
	* gdb.base/bp-cmds-run-with-ex.gdb: New file.
	* gdb.gdb/python-interrupts.exp: Update the call to
	'catch_command_errors' with the new argument.
	* gdb.gdb/python-selftest.exp: Ditto.

gdb/ChangeLog

@@ -1,3 +1,9 @@
+2020-12-07  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* main.c (catch_command_errors): Add a flag parameter; invoke
+	`bpstat_do_actions` if the flag is set.
+	(execute_cmdargs): Update a call to `catch_command_errors`.
+
 2020-12-07  Tom de Vries  <tdevries@suse.de>
 
 	* ada-lang.c (replace_operator_with_call): Handle shrink resize.

gdb/main.c

@@ -439,7 +439,8 @@ typedef void (catch_command_errors_const_ftype) (const char *, int);
 
 static int
 catch_command_errors (catch_command_errors_const_ftype command,
-		      const char *arg, int from_tty)
+		      const char *arg, int from_tty,
+		      bool do_bp_actions = false)
 {
   try
     {
@@ -448,6 +449,10 @@ catch_command_errors (catch_command_errors_const_ftype command,
       command (arg, from_tty);
 
       maybe_wait_sync_command_done (was_sync);
+
+      /* Do any commands attached to breakpoint we stopped at.  */
+      if (do_bp_actions)
+	bpstat_do_actions ();
     }
   catch (const gdb_exception &e)
     {
@@ -531,7 +536,7 @@ execute_cmdargs (const std::vector<struct cmdarg> *cmdarg_vec,
 				     !batch_flag);
       else if (cmdarg_p.type == cmd_type)
 	*ret = catch_command_errors (execute_command, cmdarg_p.string,
-				     !batch_flag);
+				     !batch_flag, true);
     }
 }
 

gdb/testsuite/ChangeLog

@@ -1,3 +1,12 @@
+2020-12-07  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* gdb.base/bp-cmds-run-with-ex.c: New file.
+	* gdb.base/bp-cmds-run-with-ex.exp: New file.
+	* gdb.base/bp-cmds-run-with-ex.gdb: New file.
+	* gdb.gdb/python-interrupts.exp: Update the call to
+	'catch_command_errors' with the new argument.
+	* gdb.gdb/python-selftest.exp: Ditto.
+
 2020-12-04  Simon Marchi  <simon.marchi@efficios.com>
 
 	* gdb.arch/amd64-disp-step-avx.exp: Adjust pattern.

gdb/testsuite/gdb.base/bp-cmds-run-with-ex.c

@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2020 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/>.  */
+
+int
+main ()
+{
+  return 0;
+}

gdb/testsuite/gdb.base/bp-cmds-run-with-ex.exp

@@ -0,0 +1,49 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2020 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 breakpoint commands are taken into account when the
+# debuggee program is executed with a "run" command given through the
+# '-ex' option.
+
+standard_testfile
+
+if {[build_executable "failed to prepare" $testfile $srcfile]} {
+    return -1
+}
+
+set script_file $srcdir/$subdir/$testfile.gdb
+
+save_vars { GDBFLAGS } {
+    append GDBFLAGS " -x ${script_file}"
+    append GDBFLAGS " -ex run"
+    append GDBFLAGS " --args ${binfile}"
+
+    gdb_exit
+    if {[gdb_spawn] != 0} {
+	fail "spawn gdb"
+	return -1
+    }
+}
+
+gdb_test_multiple "" "execute bp commands" {
+    -re " = 123\r\n$gdb_prompt $" {
+	pass $gdb_test_name
+    }
+    -re "Don't know how to run.*$gdb_prompt $" {
+	unsupported $gdb_test_name
+    }
+}

gdb/testsuite/gdb.base/bp-cmds-run-with-ex.gdb

@@ -0,0 +1,19 @@
+# Copyright 2020 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/>.
+
+break main
+commands
+  print 123
+end

gdb/testsuite/gdb.gdb/python-interrupts.exp

@@ -25,7 +25,7 @@ proc test_python_interrupts {} {
     }
 
     gdb_breakpoint set_active_ext_lang temporary
-    gdb_test "call catch_command_errors(execute_command, \"python print(5)\", 0)" \
+    gdb_test "call catch_command_errors(execute_command, \"python print(5)\", 0, true)" \
 	"Temporary breakpoint.*silently stop."
     gdb_test "signal SIGINT" \
 	"KeyboardInterrupt.*Error while executing Python code."

gdb/testsuite/gdb.gdb/python-selftest.exp

@@ -22,7 +22,7 @@ proc selftest_python {} {
     }
 
     gdb_test_no_output "set variable gdb_python_initialized = 0"
-    gdb_test "call catch_command_errors(execute_command, \"python print(5)\", 0)" \
+    gdb_test "call catch_command_errors(execute_command, \"python print(5)\", 0, true)" \
 	"Python not initialized.* = 0"
     return 0
 }