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diff --git a/scripts/test_printers_common.py b/scripts/test_printers_common.py
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+# Common functions and variables for testing the Python pretty printers.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+"""These tests require PExpect 4.0 or newer.
+
+Exported constants:
+    PASS, FAIL, UNSUPPORTED (int): Test exit codes, as per evaluate-test.sh.
+"""
+
+import os
+import re
+from test_printers_exceptions import *
+
+PASS = 0
+FAIL = 1
+UNSUPPORTED = 77
+
+gdb_bin = 'gdb'
+gdb_options = '-q -nx'
+gdb_invocation = '{0} {1}'.format(gdb_bin, gdb_options)
+pexpect_min_version = 4
+gdb_min_version = (7, 8)
+encoding = 'utf-8'
+
+try:
+    import pexpect
+except ImportError:
+    print('PExpect 4.0 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+pexpect_version = pexpect.__version__.split('.')[0]
+
+if int(pexpect_version) < pexpect_min_version:
+    print('PExpect 4.0 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+if not pexpect.which(gdb_bin):
+    print('gdb 7.8 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+timeout = 5
+TIMEOUTFACTOR = os.environ.get('TIMEOUTFACTOR')
+
+if TIMEOUTFACTOR:
+    timeout = int(TIMEOUTFACTOR)
+
+try:
+    # Check the gdb version.
+    version_cmd = '{0} --version'.format(gdb_invocation, timeout=timeout)
+    gdb_version_out = pexpect.run(version_cmd, encoding=encoding)
+
+    # The gdb version string is "GNU gdb <PKGVERSION><version>", where
+    # PKGVERSION can be any text.  We assume that there'll always be a space
+    # between PKGVERSION and the version number for the sake of the regexp.
+    version_match = re.search(r'GNU gdb .* ([1-9]+)\.([0-9]+)', gdb_version_out)
+
+    if not version_match:
+        print('The gdb version string (gdb -v) is incorrectly formatted.')
+        exit(UNSUPPORTED)
+
+    gdb_version = (int(version_match.group(1)), int(version_match.group(2)))
+
+    if gdb_version < gdb_min_version:
+        print('gdb 7.8 or newer must be installed to test the pretty printers.')
+        exit(UNSUPPORTED)
+
+    # Check if gdb supports Python.
+    gdb_python_cmd = '{0} -ex "python import os" -batch'.format(gdb_invocation,
+                                                                timeout=timeout)
+    gdb_python_error = pexpect.run(gdb_python_cmd, encoding=encoding)
+
+    if gdb_python_error:
+        print('gdb must have python support to test the pretty printers.')
+        exit(UNSUPPORTED)
+
+    # If everything's ok, spawn the gdb process we'll use for testing.
+    gdb = pexpect.spawn(gdb_invocation, echo=False, timeout=timeout,
+                        encoding=encoding)
+    gdb_prompt = u'\(gdb\)'
+    gdb.expect(gdb_prompt)
+
+except pexpect.ExceptionPexpect as exception:
+    print('Error: {0}'.format(exception))
+    exit(FAIL)
+
+def test(command, pattern=None):
+    """Sends 'command' to gdb and expects the given 'pattern'.
+
+    If 'pattern' is None, simply consumes everything up to and including
+    the gdb prompt.
+
+    Args:
+        command (string): The command we'll send to gdb.
+        pattern (raw string): A pattern the gdb output should match.
+
+    Returns:
+        string: The string that matched 'pattern', or an empty string if
+            'pattern' was None.
+    """
+
+    match = ''
+
+    gdb.sendline(command)
+
+    if pattern:
+        # PExpect does a non-greedy match for '+' and '*'.  Since it can't look
+        # ahead on the gdb output stream, if 'pattern' ends with a '+' or a '*'
+        # we may end up matching only part of the required output.
+        # To avoid this, we'll consume 'pattern' and anything that follows it
+        # up to and including the gdb prompt, then extract 'pattern' later.
+        index = gdb.expect([u'{0}.+{1}'.format(pattern, gdb_prompt),
+                            pexpect.TIMEOUT])
+
+        if index == 0:
+            # gdb.after now contains the whole match.  Extract the text that
+            # matches 'pattern'.
+            match = re.match(pattern, gdb.after, re.DOTALL).group()
+        elif index == 1:
+            # We got a timeout exception.  Print information on what caused it
+            # and bail out.
+            error = ('Response does not match the expected pattern.\n'
+                     'Command: {0}\n'
+                     'Expected pattern: {1}\n'
+                     'Response: {2}'.format(command, pattern, gdb.before))
+
+            raise pexpect.TIMEOUT(error)
+    else:
+        # Consume just the the gdb prompt.
+        gdb.expect(gdb_prompt)
+
+    return match
+
+def init_test(test_bin, printer_files, printer_names):
+    """Loads the test binary file and the required pretty printers to gdb.
+
+    Args:
+        test_bin (string): The name of the test binary file.
+        pretty_printers (list of strings): A list with the names of the pretty
+            printer files.
+    """
+
+    # Load all the pretty printer files.  We're assuming these are safe.
+    for printer_file in printer_files:
+        test('source {0}'.format(printer_file))
+
+    # Disable all the pretty printers.
+    test('disable pretty-printer', r'0 of [0-9]+ printers enabled')
+
+    # Enable only the required printers.
+    for printer in printer_names:
+        test('enable pretty-printer {0}'.format(printer),
+             r'[1-9][0-9]* of [1-9]+ printers enabled')
+
+    # Finally, load the test binary.
+    test('file {0}'.format(test_bin))
+
+def go_to_main():
+    """Executes a gdb 'start' command, which takes us to main."""
+
+    test('start', r'main')
+
+def get_line_number(file_name, string):
+    """Returns the number of the line in which 'string' appears within a file.
+
+    Args:
+        file_name (string): The name of the file we'll search through.
+        string (string): The string we'll look for.
+
+    Returns:
+        int: The number of the line in which 'string' appears, starting from 1.
+    """
+    number = -1
+
+    with open(file_name) as src_file:
+        for i, line in enumerate(src_file):
+            if string in line:
+                number = i + 1
+                break
+
+    if number == -1:
+        raise NoLineError(file_name, string)
+
+    return number
+
+def break_at(file_name, string, temporary=True, thread=None):
+    """Places a breakpoint on the first line in 'file_name' containing 'string'.
+
+    'string' is usually a comment like "Stop here".  Notice this may fail unless
+    the comment is placed inline next to actual code, e.g.:
+
+        ...
+        /* Stop here */
+        ...
+
+    may fail, while:
+
+        ...
+        some_func(); /* Stop here */
+        ...
+
+    will succeed.
+
+    If 'thread' isn't None, the breakpoint will be set for all the threads.
+    Otherwise, it'll be set only for 'thread'.
+
+    Args:
+        file_name (string): The name of the file we'll place the breakpoint in.
+        string (string): A string we'll look for inside the file.
+            We'll place a breakpoint on the line which contains it.
+        temporary (bool): Whether the breakpoint should be automatically deleted
+            after we reach it.
+        thread (int): The number of the thread we'll place the breakpoint for,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        thread_str = ''
+    else:
+        thread_str = 'thread {0}'.format(thread)
+
+    if temporary:
+        command = 'tbreak'
+        break_type = 'Temporary breakpoint'
+    else:
+        command = 'break'
+        break_type = 'Breakpoint'
+
+    line_number = str(get_line_number(file_name, string))
+
+    test('{0} {1}:{2} {3}'.format(command, file_name, line_number, thread_str),
+         r'{0} [0-9]+ at 0x[a-f0-9]+: file {1}, line {2}\.'.format(break_type,
+                                                                   file_name,
+                                                                   line_number))
+
+def continue_cmd(thread=None):
+    """Executes a gdb 'continue' command.
+
+    If 'thread' isn't None, the command will be applied to all the threads.
+    Otherwise, it'll be applied only to 'thread'.
+
+    Args:
+        thread (int): The number of the thread we'll apply the command to,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        command = 'continue'
+    else:
+        command = 'thread apply {0} continue'.format(thread)
+
+    test(command)
+
+def next_cmd(count=1, thread=None):
+    """Executes a gdb 'next' command.
+
+    If 'thread' isn't None, the command will be applied to all the threads.
+    Otherwise, it'll be applied only to 'thread'.
+
+    Args:
+        count (int): The 'count' argument of the 'next' command.
+        thread (int): The number of the thread we'll apply the command to,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        command = 'next'
+    else:
+        command = 'thread apply {0} next'
+
+    test('{0} {1}'.format(command, count))
+
+def select_thread(thread):
+    """Selects the thread indicated by 'thread'.
+
+    Args:
+        thread (int): The number of the thread we'll switch to, as seen by gdb.
+            This should be greater than zero.
+    """
+
+    if thread > 0:
+        test('thread {0}'.format(thread))
+
+def get_current_thread_lwpid():
+    """Gets the current thread's Lightweight Process ID.
+
+    Returns:
+        string: The current thread's LWP ID.
+    """
+
+    # It's easier to get the LWP ID through the Python API than the gdb CLI.
+    command = 'python print(gdb.selected_thread().ptid[1])'
+
+    return test(command, r'[0-9]+')
+
+def set_scheduler_locking(mode):
+    """Executes the gdb 'set scheduler-locking' command.
+
+    Args:
+        mode (bool): Whether the scheduler locking mode should be 'on'.
+    """
+    modes = {
+        True: 'on',
+        False: 'off'
+    }
+
+    test('set scheduler-locking {0}'.format(modes[mode]))
+
+def test_printer(var, to_string, children=None, is_ptr=True):
+    """ Tests the output of a pretty printer.
+
+    For a variable called 'var', this tests whether its associated printer
+    outputs the expected 'to_string' and children (if any).
+
+    Args:
+        var (string): The name of the variable we'll print.
+        to_string (raw string): The expected output of the printer's 'to_string'
+            method.
+        children (map {raw string->raw string}): A map with the expected output
+            of the printer's children' method.
+        is_ptr (bool): Whether 'var' is a pointer, and thus should be
+            dereferenced.
+    """
+
+    if is_ptr:
+        var = '*{0}'.format(var)
+
+    test('print {0}'.format(var), to_string)
+
+    if children:
+        for name, value in children.items():
+            # Children are shown as 'name = value'.
+            test('print {0}'.format(var), r'{0} = {1}'.format(name, value))
+
+def check_debug_symbol(symbol):
+    """ Tests whether a given debugging symbol exists.
+
+    If the symbol doesn't exist, raises a DebugError.
+
+    Args:
+        symbol (string): The symbol we're going to check for.
+    """
+
+    try:
+        test('ptype {0}'.format(symbol), r'type = {0}'.format(symbol))
+
+    except pexpect.TIMEOUT:
+        # The symbol doesn't exist.
+        raise DebugError(symbol)