gdb/testsuite/gdb.python/py-xmethods.py

# Copyright 2014-2018 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 file is part of the GDB testsuite.  It test the xmethods support
# in the Python extension language.

import gdb
import re

from gdb.xmethod import XMethod
from gdb.xmethod import XMethodMatcher, XMethodWorker
from gdb.xmethod import SimpleXMethodMatcher


def A_plus_A(obj, opr):
  print('From Python <A_plus_A>:')
  return obj['a'] + opr['a']


def plus_plus_A(obj):
  print('From Python <plus_plus_A>:')
  return obj['a'] + 1


def A_geta(obj):
  print('From Python <A_geta>:')
  return obj['a']


def A_getarrayind(obj, index):
  print('From Python <A_getarrayind>:')
  return obj['array'][index]

def A_indexoper(obj, index):
  return obj['array'][index].reference_value()

def B_indexoper(obj, index):
  return obj['array'][index].const_value().reference_value()


type_A = gdb.parse_and_eval('(dop::A *) 0').type.target()
type_B = gdb.parse_and_eval('(dop::B *) 0').type.target()
type_int = gdb.parse_and_eval('(int *) 0').type.target()


# The E class matcher and worker test two things:
#   1. xmethod returning None.
#   2. Matcher returning a list of workers.

class E_method_char_worker(XMethodWorker):
    def __init__(self):
        pass

    def get_arg_types(self):
        return gdb.lookup_type('char')

    def get_result_type(self, obj, arg):
        return gdb.lookup_type('void')

    def __call__(self, obj, arg):
        print('From Python <E_method_char>')
        return None


class E_method_int_worker(XMethodWorker):
    def __init__(self):
        pass

    def get_arg_types(self):
        return gdb.lookup_type('int')

    # Note: get_result_type method elided on purpose

    def __call__(self, obj, arg):
        print('From Python <E_method_int>')
        return None


class E_method_matcher(XMethodMatcher):
    def __init__(self):
        XMethodMatcher.__init__(self, 'E_methods')
        self.methods = [XMethod('method_int'), XMethod('method_char')]

    def match(self, class_type, method_name):
        class_tag = class_type.unqualified().tag
        if not re.match('^dop::E$', class_tag):
            return None
        if not re.match('^method$', method_name):
            return None
        workers = []
        if self.methods[0].enabled:
            workers.append(E_method_int_worker())
        if self.methods[1].enabled:
            workers.append(E_method_char_worker())
        return workers


# The G class method matcher and worker illustrate how to write
# xmethod matchers and workers for template classes and template
# methods.

class G_size_diff_worker(XMethodWorker):
    def __init__(self, class_template_type, method_template_type):
        self._class_template_type = class_template_type
        self._method_template_type = method_template_type

    def get_arg_types(self):
        pass

    def __call__(self, obj):
        print('From Python G<>::size_diff()')
        return (self._method_template_type.sizeof -
                self._class_template_type.sizeof)


class G_size_mul_worker(XMethodWorker):
    def __init__(self, class_template_type, method_template_val):
        self._class_template_type = class_template_type
        self._method_template_val = method_template_val

    def get_arg_types(self):
        pass

    def __call__(self, obj):
        print('From Python G<>::size_mul()')
        return self._class_template_type.sizeof * self._method_template_val


class G_mul_worker(XMethodWorker):
    def __init__(self, class_template_type, method_template_type):
        self._class_template_type = class_template_type
        self._method_template_type = method_template_type

    def get_arg_types(self):
        return self._method_template_type

    def __call__(self, obj, arg):
        print('From Python G<>::mul()')
        return obj['t'] * arg


class G_methods_matcher(XMethodMatcher):
    def __init__(self):
        XMethodMatcher.__init__(self, 'G_methods')
        self.methods = [XMethod('size_diff'),
                        XMethod('size_mul'),
                        XMethod('mul')]

    def _is_enabled(self, name):
        for method in self.methods:
            if method.name == name and method.enabled:
                return True

    def match(self, class_type, method_name):
        class_tag = class_type.unqualified().tag
        if not re.match('^dop::G<[ ]*[_a-zA-Z][ _a-zA-Z0-9]*>$',
                        class_tag):
            return None
        t_name = class_tag[7:-1]
        try:
            t_type = gdb.lookup_type(t_name)
        except gdb.error:
            return None
        if re.match('^size_diff<[ ]*[_a-zA-Z][ _a-zA-Z0-9]*>$', method_name):
            if not self._is_enabled('size_diff'):
                return None
            t1_name = method_name[10:-1]
            try:
                t1_type = gdb.lookup_type(t1_name)
                return G_size_diff_worker(t_type, t1_type)
            except gdb.error:
                return None
        if re.match('^size_mul<[ ]*[0-9]+[ ]*>$', method_name):
            if not self._is_enabled('size_mul'):
                return None
            m_val = int(method_name[9:-1])
            return G_size_mul_worker(t_type, m_val)
        if re.match('^mul<[ ]*[_a-zA-Z][ _a-zA-Z0-9]*>$', method_name):
            if not self._is_enabled('mul'):
                return None
            t1_name = method_name[4:-1]
            try:
                t1_type = gdb.lookup_type(t1_name)
                return G_mul_worker(t_type, t1_type)
            except gdb.error:
                return None


global_dm_list = [
    SimpleXMethodMatcher('A_plus_A',
                         '^dop::A$',
                         'operator\+',
                         A_plus_A,
                         # This is a replacement, hence match the arg type
                         # exactly!
                         type_A.const().reference()),
    SimpleXMethodMatcher('plus_plus_A',
                         '^dop::A$',
                         'operator\+\+',
                         plus_plus_A),
    SimpleXMethodMatcher('A_geta',
                         '^dop::A$',
                         '^geta$',
                         A_geta),
    SimpleXMethodMatcher('A_getarrayind',
                         '^dop::A$',
                         '^getarrayind$',
                         A_getarrayind,
                         type_int),
    SimpleXMethodMatcher('A_indexoper',
                         '^dop::A$',
                         'operator\\[\\]',
                         A_indexoper,
                         type_int),
    SimpleXMethodMatcher('B_indexoper',
                         '^dop::B$',
                         'operator\\[\\]',
                         B_indexoper,
                         type_int)
]

for matcher in global_dm_list:
    gdb.xmethod.register_xmethod_matcher(gdb, matcher)
gdb.xmethod.register_xmethod_matcher(gdb.current_progspace(),
                                     G_methods_matcher())
gdb.xmethod.register_xmethod_matcher(gdb.current_progspace(),
                                     E_method_matcher())