Merge https://github.com/markflorisson88/cython

Cython/Compiler/CmdLine.py

@@ -2,6 +2,7 @@
 #   Cython - Command Line Parsing
 #
 
+import os
 import sys
 import Options
 
@@ -27,6 +28,7 @@ Options:
                                  Level indicates aggressiveness, default 0 releases nothing. 
   -w, --working <directory>      Sets the working directory for Cython (the directory modules 
                                  are searched from)
+  --gdb                          Output debug information for cygdb
 
   -D, --no-docstrings            Remove docstrings.
   -a, --annotate                 Produce a colorized HTML version of the source.
@@ -114,6 +116,9 @@ def parse_command_line(args):
                 Options.convert_range = True
             elif option == "--line-directives":
                 options.emit_linenums = True
+            elif option == "--gdb":
+                options.gdb_debug = True
+                options.output_dir = os.curdir
             elif option == '-2':
                 options.language_level = 2
             elif option == '-3':

Cython/Compiler/Code.py

@@ -916,6 +916,14 @@ class CCodeWriter(object):
         return self.buffer.getvalue()
 
     def write(self, s):
+        # also put invalid markers (lineno 0), to indicate that those lines 
+        # have no Cython source code correspondence
+        if self.marker is None:
+            cython_lineno = self.last_marker_line
+        else:
+            cython_lineno = self.marker[0]
+        
+        self.buffer.markers.extend([cython_lineno] * s.count('\n'))
         self.buffer.write(s)
 
     def insertion_point(self):
@@ -1000,6 +1008,7 @@ class CCodeWriter(object):
             self.emit_marker()
         if self.emit_linenums and self.last_marker_line != 0:
             self.write('\n#line %s "%s"\n' % (self.last_marker_line, self.source_desc))
+        
         if code:
             if safe:
                 self.put_safe(code)

Cython/Compiler/Errors.py

@@ -97,6 +97,10 @@ class CompilerCrash(CompileError):
             message += u'%s: %s' % (cause.__class__.__name__, cause)
         CompileError.__init__(self, pos, message)
 
+class NoElementTreeInstalledException(PyrexError):
+    """raised when the user enabled options.gdb_debug but no ElementTree 
+    implementation was found
+    """
 
 listing_file = None
 num_errors = 0

Cython/Compiler/Main.py

@@ -13,7 +13,9 @@ except NameError:
     # Python 2.3
     from sets import Set as set
 
+import itertools
 from time import time
+
 import Code
 import Errors
 import Parsing
@@ -85,6 +87,8 @@ class Context(object):
 
         self.set_language_level(language_level)
         
+        self.gdb_debug_outputwriter = None
+
     def set_language_level(self, level):
         self.language_level = level
         if level >= 3:
@@ -178,13 +182,22 @@ class Context(object):
             from Cython.TestUtils import TreeAssertVisitor
             test_support.append(TreeAssertVisitor())
 
-        return ([
-                create_parse(self),
-            ] + self.create_pipeline(pxd=False, py=py) + test_support + [
-                inject_pxd_code,
-                abort_on_errors,
-                generate_pyx_code,
-            ])
+        if options.gdb_debug:
+            from Cython.Debugger import DebugWriter
+            from ParseTreeTransforms import DebugTransform
+            self.gdb_debug_outputwriter = DebugWriter.CythonDebugWriter(
+                options.output_dir)
+            debug_transform = [DebugTransform(self, options, result)]
+        else:
+            debug_transform = []
+            
+        return list(itertools.chain(
+            [create_parse(self)],
+            self.create_pipeline(pxd=False, py=py),
+            test_support,
+            [inject_pxd_code, abort_on_errors],
+            debug_transform,
+            [generate_pyx_code]))
 
     def create_pxd_pipeline(self, scope, module_name):
         def parse_pxd(source_desc):
@@ -807,4 +820,5 @@ default_options = dict(
     evaluate_tree_assertions = False,
     emit_linenums = False,
     language_level = 2,
+    gdb_debug = False,
 )

Cython/Compiler/ModuleNode.py

@@ -297,12 +297,34 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         
         f = open_new_file(result.c_file)
         rootwriter.copyto(f)
+        if options.gdb_debug:
+            self._serialize_lineno_map(env, rootwriter)
         f.close()
         result.c_file_generated = 1
         if Options.annotate or options.annotate:
             self.annotate(rootwriter)
             rootwriter.save_annotation(result.main_source_file, result.c_file)
     
+    def _serialize_lineno_map(self, env, ccodewriter):
+        tb = env.context.gdb_debug_outputwriter
+        markers = ccodewriter.buffer.allmarkers()
+        
+        d = {}
+        for c_lineno, cython_lineno in enumerate(markers): 
+            if cython_lineno > 0:
+                d.setdefault(cython_lineno, []).append(c_lineno + 1)
+        
+        tb.start('LineNumberMapping')
+        for cython_lineno, c_linenos in sorted(d.iteritems()):
+                attrs = {
+                    'c_linenos': ' '.join(map(str, c_linenos)),
+                    'cython_lineno': str(cython_lineno),
+                }
+                tb.start('LineNumber', attrs)
+                tb.end('LineNumber')
+        tb.end('LineNumberMapping')
+        tb.serialize()
+        
     def find_referenced_modules(self, env, module_list, modules_seen):
         if env not in modules_seen:
             modules_seen[env] = 1

Cython/Compiler/ParseTreeTransforms.py

@@ -20,6 +20,12 @@ from Cython.Compiler.TreeFragment import TreeFragment, TemplateTransform
 from Cython.Compiler.StringEncoding import EncodedString
 from Cython.Compiler.Errors import error, warning, CompileError, InternalError
 
+
+try:
+    set
+except NameError:
+    from sets import Set as set
+
 import copy
 
 
@@ -1574,3 +1580,136 @@ class TransformBuiltinMethods(EnvTransform):
         
         self.visitchildren(node)
         return node
+
+
+class DebugTransform(CythonTransform):
+    """
+    Create debug information and all functions' visibility to extern in order
+    to enable debugging.
+    """
+    
+    def __init__(self, context, options, result):
+        super(DebugTransform, self).__init__(context)
+        self.visited = set()
+        # our treebuilder and debug output writer 
+        # (see Cython.Debugger.debug_output.CythonDebugWriter)
+        self.tb = self.context.gdb_debug_outputwriter
+        #self.c_output_file = options.output_file 
+        self.c_output_file = result.c_file
+        
+        # tells visit_NameNode whether it should register step-into functions
+        self.register_stepinto = False
+        
+    def visit_ModuleNode(self, node):
+        self.tb.module_name = node.full_module_name
+        attrs = dict(
+            module_name=node.full_module_name,
+            filename=node.pos[0].filename,
+            c_filename=self.c_output_file)
+        
+        self.tb.start('Module', attrs)
+        
+        # serialize functions
+        self.tb.start('Functions')
+        self.visitchildren(node)
+        self.tb.end('Functions')
+        
+        # 2.3 compatibility. Serialize global variables
+        self.tb.start('Globals')
+        entries = {}
+
+        for k, v in node.scope.entries.iteritems():
+            if (v.qualified_name not in self.visited and not
+                v.name.startswith('__pyx_') and not 
+                v.type.is_cfunction and not
+                v.type.is_extension_type):
+                entries[k]= v
+                
+        self.serialize_local_variables(entries)
+        self.tb.end('Globals')
+        # self.tb.end('Module') # end Module after the line number mapping in
+        # Cython.Compiler.ModuleNode.ModuleNode._serialize_lineno_map
+        return node
+    
+    def visit_FuncDefNode(self, node):
+        self.visited.add(node.local_scope.qualified_name)
+        # node.entry.visibility = 'extern'
+        if node.py_func is None:
+            pf_cname = ''
+        else:
+            pf_cname = node.py_func.entry.func_cname
+            
+        attrs = dict(
+            name=node.entry.name,
+            cname=node.entry.func_cname,
+            pf_cname=pf_cname,
+            qualified_name=node.local_scope.qualified_name,
+            lineno=str(node.pos[1]))
+        
+        self.tb.start('Function', attrs=attrs)
+        
+        self.tb.start('Locals')
+        self.serialize_local_variables(node.local_scope.entries)
+        self.tb.end('Locals')
+
+        self.tb.start('Arguments')
+        for arg in node.local_scope.arg_entries:
+            self.tb.start(arg.name)
+            self.tb.end(arg.name)
+        self.tb.end('Arguments')
+
+        self.tb.start('StepIntoFunctions')
+        self.register_stepinto = True
+        self.visitchildren(node)
+        self.register_stepinto = False
+        self.tb.end('StepIntoFunctions')
+        self.tb.end('Function')
+
+        return node
+
+    def visit_NameNode(self, node):
+        if (self.register_stepinto and 
+            node.type.is_cfunction and 
+            getattr(node, 'is_called', False) and
+            node.entry.func_cname is not None):
+            # don't check node.entry.in_cinclude, as 'cdef extern: ...' 
+            # declared functions are not 'in_cinclude'. 
+            # This means we will list called 'cdef' functions as 
+            # "step into functions", but this is not an issue as they will be 
+            # recognized as Cython functions anyway.
+            attrs = dict(name=node.entry.func_cname)
+            self.tb.start('StepIntoFunction', attrs=attrs)
+            self.tb.end('StepIntoFunction')
+        
+        self.visitchildren(node)
+        return node
+    
+    def serialize_local_variables(self, entries):
+        for entry in entries.values():
+            if entry.type.is_pyobject:
+                vartype = 'PythonObject'
+            else:
+                vartype = 'CObject'
+            
+            cname = entry.cname
+            # if entry.type.is_extension_type:
+                # cname = entry.type.typeptr_cname
+            
+            if not entry.pos:
+                # this happens for variables that are not in the user's code,
+                # e.g. for the global __builtins__, __doc__, etc. We can just
+                # set the lineno to 0 for those.
+                lineno = '0'
+            else:
+                lineno = str(entry.pos[1])
+                
+            attrs = dict(
+                name=entry.name,
+                cname=cname,
+                qualified_name=entry.qualified_name,
+                type=vartype,
+                lineno=lineno)
+            
+            self.tb.start('LocalVar', attrs)
+            self.tb.end('LocalVar')
+        

Cython/Compiler/Tests/TestParseTreeTransforms.py

+import os
+
+from Cython.Compiler import CmdLine
 from Cython.TestUtils import TransformTest
 from Cython.Compiler.ParseTreeTransforms import *
 from Cython.Compiler.Nodes import *
 
+
 class TestNormalizeTree(TransformTest):
     def test_parserbehaviour_is_what_we_coded_for(self):
         t = self.fragment(u"if x: y").root
@@ -140,6 +144,80 @@ class TestWithTransform(object): # (TransformTest): # Disabled!
         """, t)
                           
 
+if sys.version_info[:2] > (2, 4):
+    from Cython.Debugger import DebugWriter
+    from Cython.Debugger.Tests.TestLibCython import DebuggerTestCase
+else:
+    # skip test, don't let it inherit unittest.TestCase
+    DebuggerTestCase = object
+
+class TestDebugTransform(DebuggerTestCase):
+    
+    def elem_hasattrs(self, elem, attrs):
+        # we shall supporteth python 2.3 !
+        return all([attr in elem.attrib for attr in attrs])
+    
+    def test_debug_info(self):
+        try:
+            assert os.path.exists(self.debug_dest)
+            
+            t = DebugWriter.etree.parse(self.debug_dest)
+            # the xpath of the standard ElementTree is primitive, don't use
+            # anything fancy
+            L = list(t.find('/Module/Globals'))
+            # assertTrue is retarded, use the normal assert statement
+            assert L
+            xml_globals = dict(
+                            [(e.attrib['name'], e.attrib['type']) for e in L])
+            self.assertEqual(len(L), len(xml_globals))
+            
+            L = list(t.find('/Module/Functions'))
+            assert L
+            xml_funcs = dict([(e.attrib['qualified_name'], e) for e in L])
+            self.assertEqual(len(L), len(xml_funcs))
+            
+            # test globals
+            self.assertEqual('CObject', xml_globals.get('c_var'))
+            self.assertEqual('PythonObject', xml_globals.get('python_var'))
+            
+            # test functions
+            funcnames = 'codefile.spam', 'codefile.ham', 'codefile.eggs'
+            required_xml_attrs = 'name', 'cname', 'qualified_name'
+            assert all([f in xml_funcs for f in funcnames])
+            spam, ham, eggs = [xml_funcs[funcname] for funcname in funcnames]
+            
+            self.assertEqual(spam.attrib['name'], 'spam')
+            self.assertNotEqual('spam', spam.attrib['cname'])
+            assert self.elem_hasattrs(spam, required_xml_attrs)
+
+            # test locals of functions
+            spam_locals = list(spam.find('Locals'))
+            assert spam_locals
+            spam_locals.sort(key=lambda e: e.attrib['name'])
+            names = [e.attrib['name'] for e in spam_locals]
+            self.assertEqual(list('abcd'), names)
+            assert self.elem_hasattrs(spam_locals[0], required_xml_attrs)
+            
+            # test arguments of functions
+            spam_arguments = list(spam.find('Arguments'))
+            assert spam_arguments
+            self.assertEqual(1, len(list(spam_arguments)))
+            
+            # test step-into functions
+            step_into = spam.find('StepIntoFunctions')
+            spam_stepinto = [x.attrib['name'] for x in step_into]
+            assert spam_stepinto
+            self.assertEqual(2, len(spam_stepinto))
+            assert 'puts' in spam_stepinto
+            assert 'some_c_function' in spam_stepinto
+        except:
+            print open(self.debug_dest).read()
+            raise
+            
+
+
+    
+
 if __name__ == "__main__":
     import unittest
     unittest.main()

Cython/Debugger/Cygdb.py

+#!/usr/bin/env python
+
+"""
+The Cython debugger
+
+The current directory should contain a directory named 'cython_debug', or a
+path to the cython project directory should be given (the parent directory of
+cython_debug).
+
+Additional gdb args can be provided only if a path to the project directory is 
+given.
+"""
+
+import os
+import sys
+import glob
+import tempfile
+import textwrap
+import subprocess
+
+usage = "Usage: cygdb [PATH [GDB_ARGUMENTS]]"
+
+def make_command_file(path_to_debug_info, prefix_code='', no_import=False):
+    if not no_import:
+        pattern = os.path.join(path_to_debug_info, 
+                               'cython_debug',
+                               'cython_debug_info_*')
+        debug_files = glob.glob(pattern)
+
+        if not debug_files:
+            sys.exit('%s.\nNo debug files were found in %s. Aborting.' % (
+                                   usage, os.path.abspath(path_to_debug_info)))
+    
+    fd, tempfilename = tempfile.mkstemp()
+    f = os.fdopen(fd, 'w')
+    f.write(prefix_code)
+    f.write('set breakpoint pending on\n')
+    f.write("set print pretty on\n")
+    f.write('python from Cython.Debugger import libcython, libpython\n')
+    
+    if no_import:
+        # don't do this, this overrides file command in .gdbinit
+        # f.write("file %s\n" % sys.executable)
+        pass
+    else:
+        path = os.path.join(path_to_debug_info, "cython_debug", "interpreter")
+        interpreter = open(path).read()
+        f.write("file %s\n" % interpreter)
+        f.write('\n'.join('cy import %s\n' % fn for fn in debug_files))
+        f.write(textwrap.dedent('''\
+            python
+            import sys
+            try:
+                gdb.lookup_type('PyModuleObject')
+            except RuntimeError:
+                sys.stderr.write(
+                    'Python was not compiled with debug symbols (or it was '
+                    'stripped). Some functionality may not work (properly).\\n')
+            end
+        '''))
+    
+    f.close()
+    
+    return tempfilename
+
+def main(path_to_debug_info=None, gdb_argv=None, no_import=False):
+    """
+    Start the Cython debugger. This tells gdb to import the Cython and Python
+    extensions (libcython.py and libpython.py) and it enables gdb's pending 
+    breakpoints.
+    
+    path_to_debug_info is the path to the Cython build directory
+    gdb_argv is the list of options to gdb
+    no_import tells cygdb whether it should import debug information
+    """
+    if path_to_debug_info is None:
+        if len(sys.argv) > 1:
+            path_to_debug_info = sys.argv[1]
+        else:
+            path_to_debug_info = os.curdir
+    
+    if gdb_argv is None:
+        gdb_argv = sys.argv[2:]
+    
+    if path_to_debug_info == '--':
+        no_import = True
+    
+    tempfilename = make_command_file(path_to_debug_info, no_import=no_import)
+    p = subprocess.Popen(['gdb', '-command', tempfilename] + gdb_argv)
+    while True:
+        try:
+            p.wait()
+        except KeyboardInterrupt:
+            pass
+        else:
+            break
+    os.remove(tempfilename)

Cython/Debugger/DebugWriter.py

+from __future__ import with_statement
+
+import os
+import sys
+import errno
+
+try:
+  from lxml import etree
+  have_lxml = True
+except ImportError:
+    have_lxml = False
+    try:
+        # Python 2.5
+        from xml.etree import cElementTree as etree
+    except ImportError:
+        try:
+            # Python 2.5
+            from xml.etree import ElementTree as etree
+        except ImportError:
+            try:
+                # normal cElementTree install
+                import cElementTree as etree
+            except ImportError:
+                try:
+                    # normal ElementTree install
+                    import elementtree.ElementTree as etree
+                except ImportError:
+                    etree = None
+
+from Cython.Compiler import Errors
+
+
+class CythonDebugWriter(object):
+    """
+    Class to output debugging information for cygdb
+    
+    It writes debug information to cython_debug/cython_debug_info_<modulename>
+    in the build directory.
+    """
+    
+    def __init__(self, output_dir):
+        if etree is None:
+            raise Errors.NoElementTreeInstalledException()
+        
+        self.output_dir = os.path.join(output_dir, 'cython_debug')
+        self.tb = etree.TreeBuilder()
+        # set by Cython.Compiler.ParseTreeTransforms.DebugTransform
+        self.module_name = None
+        self.start('cython_debug', attrs=dict(version='1.0'))
+    
+    def start(self, name, attrs=None):
+        self.tb.start(name, attrs or {})
+    
+    def end(self, name):
+        self.tb.end(name)
+
+    def serialize(self):
+        self.tb.end('Module')
+        self.tb.end('cython_debug')
+        xml_root_element = self.tb.close()
+
+        try:
+            os.makedirs(self.output_dir)
+        except OSError, e:
+            if e.errno != errno.EEXIST:
+                raise
+
+        et = etree.ElementTree(xml_root_element)
+        kw = {}
+        if have_lxml:
+            kw['pretty_print'] = True
+        
+        fn = "cython_debug_info_" + self.module_name
+        et.write(os.path.join(self.output_dir, fn), encoding="UTF-8", **kw)
+        
+        interpreter_path = os.path.join(self.output_dir, 'interpreter')
+        with open(interpreter_path, 'w') as f:
+            f.write(sys.executable)

Cython/Debugger/Tests/TestLibCython.py

+from __future__ import with_statement
+
+import os
+import re
+import sys
+import uuid
+import shutil
+import warnings
+import textwrap
+import unittest
+import tempfile
+import subprocess
+import distutils.core
+from distutils import sysconfig
+from distutils import ccompiler
+
+import runtests
+import Cython.Distutils.extension
+from Cython.Debugger import Cygdb as cygdb
+
+root = os.path.dirname(os.path.abspath(__file__))
+codefile = os.path.join(root, 'codefile')
+cfuncs_file = os.path.join(root, 'cfuncs.c')
+with open(codefile) as f:
+    source_to_lineno = dict((line.strip(), i + 1) for i, line in enumerate(f))
+
+class DebuggerTestCase(unittest.TestCase):
+    
+    def setUp(self):
+        """
+        Run gdb and have cygdb import the debug information from the code
+        defined in TestParseTreeTransforms's setUp method
+        """
+        self.tempdir = tempfile.mkdtemp()
+        self.destfile = os.path.join(self.tempdir, 'codefile.pyx')
+        self.debug_dest = os.path.join(self.tempdir, 
+                                      'cython_debug', 
+                                      'cython_debug_info_codefile')
+        self.cfuncs_destfile = os.path.join(self.tempdir, 'cfuncs')
+        
+        self.cwd = os.getcwd()
+        os.chdir(self.tempdir)
+        
+        shutil.copy(codefile, self.destfile)
+        shutil.copy(cfuncs_file, self.cfuncs_destfile + '.c')
+        
+        compiler = ccompiler.new_compiler()
+        compiler.compile(['cfuncs.c'], debug=True)
+        
+        opts = dict(
+            test_directory=self.tempdir,
+            module='codefile',
+        )
+        
+        cython_compile_testcase = runtests.CythonCompileTestCase(
+            workdir=self.tempdir,
+            # we clean up everything (not only compiled files)
+            cleanup_workdir=False,
+            **opts
+        )
+        
+        cython_compile_testcase.run_cython(
+            targetdir=self.tempdir,
+            incdir=None,
+            annotate=False,
+            extra_compile_options={
+                'gdb_debug':True,
+                'output_dir':self.tempdir,
+            },
+            **opts
+        )
+        
+        cython_compile_testcase.run_distutils(
+            incdir=None,
+            workdir=self.tempdir,
+            extra_extension_args={'extra_objects':['cfuncs.o']},
+            **opts
+        )
+        
+        # ext = Cython.Distutils.extension.Extension(
+            # 'codefile',
+            # ['codefile.pyx'], 
+            # pyrex_gdb=True,
+            # extra_objects=['cfuncs.o'])
+        # 
+        # distutils.core.setup(
+            # script_args=['build_ext', '--inplace'],
+            # ext_modules=[ext],
+            # cmdclass=dict(build_ext=Cython.Distutils.build_ext)
+        # )
+        
+    def tearDown(self):
+        os.chdir(self.cwd)
+        shutil.rmtree(self.tempdir)
+
+
+class GdbDebuggerTestCase(DebuggerTestCase):
+    def setUp(self):
+        super(GdbDebuggerTestCase, self).setUp()
+        
+        prefix_code = textwrap.dedent('''\
+            python
+                
+            import os
+            import sys
+            import traceback
+            
+            def excepthook(type, value, tb):
+                traceback.print_exception(type, value, tb)
+                os._exit(1)
+            
+            sys.excepthook = excepthook
+            
+            # Have tracebacks end up on sys.stderr (gdb replaces sys.stderr
+            # with an object that calls gdb.write())
+            sys.stderr = sys.__stderr__
+            
+            end
+            ''')
+        
+        code = textwrap.dedent('''\
+            python
+            
+            from Cython.Debugger.Tests import test_libcython_in_gdb
+            test_libcython_in_gdb.main()
+            
+            end
+            ''')
+        
+        self.gdb_command_file = cygdb.make_command_file(self.tempdir, 
+                                                        prefix_code)
+        open(self.gdb_command_file, 'a').write(code)
+        
+        args = ['gdb', '-batch', '-x', self.gdb_command_file, '-n', '--args',
+                sys.executable, '-c', 'import codefile']
+        
+        paths = []
+        path = os.environ.get('PYTHONPATH')
+        if path:
+            paths.append(path)
+        paths.append(os.path.dirname(os.path.dirname(
+            os.path.abspath(Cython.__file__))))
+        env = dict(os.environ, PYTHONPATH=os.pathsep.join(paths))
+        
+        try:
+            p = subprocess.Popen(['gdb', '-v'], stdout=subprocess.PIPE)
+            have_gdb = True
+        except OSError:
+            # gdb was not installed
+            have_gdb = False
+        else:
+            gdb_version = p.stdout.read()
+            p.wait()
+            p.stdout.close()
+        
+        if have_gdb:
+            # Based on Lib/test/test_gdb.py
+            regex = "^GNU gdb [^\d]*(\d+)\.(\d+)"
+            gdb_version_number = re.search(regex, gdb_version).groups()
+
+        if not have_gdb or map(int, gdb_version_number) < [7, 2]:
+            self.p = None
+            warnings.warn('Skipping gdb tests, need gdb >= 7.2')
+        else:
+            self.p = subprocess.Popen(
+                args,
+                stdout=open(os.devnull, 'w'),
+                stderr=subprocess.PIPE,
+                env=env)
+        
+    def tearDown(self):
+        super(GdbDebuggerTestCase, self).tearDown()
+        if self.p:
+            self.p.stderr.close()
+            self.p.wait()
+        os.remove(self.gdb_command_file)
+        
+   
+class TestAll(GdbDebuggerTestCase):
+    
+    def test_all(self):
+        if self.p is None:
+            return
+            
+        out, err = self.p.communicate()
+        border = '*' * 30
+        start = '%s   v INSIDE GDB v   %s' % (border, border)
+        end   = '%s   ^ INSIDE GDB ^   %s' % (border, border)
+        errmsg = '\n%s\n%s%s' % (start, err, end)
+        self.assertEquals(0, self.p.wait(), errmsg)
+        sys.stderr.write(err)
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file

Cython/Debugger/Tests/cfuncs.c

+void
+some_c_function(void)
+{
+    int a, b, c;
+    
+    a = 1;
+    b = 2;
+}
\ No newline at end of file

Cython/Debugger/Tests/codefile

+cdef extern from "stdio.h":
+    int puts(char *s)
+
+cdef extern:
+    void some_c_function()
+
+import os
+
+cdef int c_var = 12
+python_var = 13
+
+def spam(a=0):
+    cdef:
+        int b, c
+    
+    b = c = d = 0
+    
+    b = 1
+    c = 2
+    int(10)
+    puts("spam")
+    os.path.join("foo", "bar")
+    some_c_function()
+    
+cdef ham():
+    pass
+    
+cpdef eggs():
+    pass
+
+cdef class SomeClass(object):
+    def spam(self):
+        pass
+
+spam()
+print "bye!"

Cython/Debugger/Tests/test_libcython_in_gdb.py

+"""
+Tests that run inside GDB.
+
+Note: debug information is already imported by the file generated by
+Cython.Debugger.Cygdb.make_command_file()
+"""
+
+import os
+import re
+import sys
+import trace
+import inspect
+import warnings
+import unittest
+import textwrap
+import tempfile
+import traceback
+import itertools
+from test import test_support
+
+import gdb
+
+from Cython.Debugger import libcython
+from Cython.Debugger import libpython
+from Cython.Debugger.Tests import TestLibCython as test_libcython
+
+
+# for some reason sys.argv is missing in gdb
+sys.argv = ['gdb']
+
+
+class DebugTestCase(unittest.TestCase):
+    """
+    Base class for test cases. On teardown it kills the inferior and unsets 
+    all breakpoints.
+    """
+    
+    def __init__(self, name):
+        super(DebugTestCase, self).__init__(name)
+        self.cy = libcython.cy
+        self.module = libcython.cy.cython_namespace['codefile']
+        self.spam_func, self.spam_meth = libcython.cy.functions_by_name['spam']
+        self.ham_func = libcython.cy.functions_by_qualified_name[
+            'codefile.ham']
+        self.eggs_func = libcython.cy.functions_by_qualified_name[
+            'codefile.eggs']
+    
+    def read_var(self, varname, cast_to=None):
+        result = gdb.parse_and_eval('$cy_cvalue("%s")' % varname)
+        if cast_to:
+            result = cast_to(result)
+        
+        return result
+    
+    def local_info(self):
+        return gdb.execute('info locals', to_string=True)
+    
+    def lineno_equals(self, source_line=None, lineno=None):
+        if source_line is not None:
+            lineno = test_libcython.source_to_lineno[source_line]
+        frame = gdb.selected_frame()
+        self.assertEqual(libcython.cy.step.lineno(frame), lineno)
+
+    def break_and_run(self, source_line):
+        break_lineno = test_libcython.source_to_lineno[source_line]
+        gdb.execute('cy break codefile:%d' % break_lineno, to_string=True)
+        gdb.execute('run', to_string=True)
+
+    def tearDown(self):
+        gdb.execute('delete breakpoints', to_string=True)
+        try:
+            gdb.execute('kill inferior 1', to_string=True)
+        except RuntimeError:
+            pass
+        
+        gdb.execute('set args -c "import codefile"')
+        
+        libcython.cy.step.static_breakpoints.clear()
+        libcython.cy.step.runtime_breakpoints.clear()
+        libcython.cy.step.init_breakpoints()
+
+class TestDebugInformationClasses(DebugTestCase):
+    
+    def test_CythonModule(self):
+        "test that debug information was parsed properly into data structures"
+        self.assertEqual(self.module.name, 'codefile')
+        global_vars = ('c_var', 'python_var', '__name__', 
+                       '__builtins__', '__doc__', '__file__')
+        assert set(global_vars).issubset(self.module.globals)
+        
+    def test_CythonVariable(self):
+        module_globals = self.module.globals
+        c_var = module_globals['c_var']
+        python_var = module_globals['python_var']
+        self.assertEqual(c_var.type, libcython.CObject)
+        self.assertEqual(python_var.type, libcython.PythonObject)
+        self.assertEqual(c_var.qualified_name, 'codefile.c_var')
+    
+    def test_CythonFunction(self):
+        self.assertEqual(self.spam_func.qualified_name, 'codefile.spam')
+        self.assertEqual(self.spam_meth.qualified_name, 
+                         'codefile.SomeClass.spam')
+        self.assertEqual(self.spam_func.module, self.module)
+        
+        assert self.eggs_func.pf_cname
+        assert not self.ham_func.pf_cname
+        assert not self.spam_func.pf_cname
+        assert not self.spam_meth.pf_cname
+        
+        self.assertEqual(self.spam_func.type, libcython.CObject)
+        self.assertEqual(self.ham_func.type, libcython.CObject)
+        
+        self.assertEqual(self.spam_func.arguments, ['a'])
+        self.assertEqual(self.spam_func.step_into_functions, 
+                         set(['puts', 'some_c_function']))
+        
+        expected_lineno = test_libcython.source_to_lineno['def spam(a=0):']
+        self.assertEqual(self.spam_func.lineno, expected_lineno)
+        self.assertEqual(sorted(self.spam_func.locals), list('abcd'))
+
+
+class TestParameters(unittest.TestCase):
+    
+    def test_parameters(self):
+        gdb.execute('set cy_colorize_code on')
+        assert libcython.parameters.colorize_code
+        gdb.execute('set cy_colorize_code off')
+        assert not libcython.parameters.colorize_code
+
+
+class TestBreak(DebugTestCase):
+
+    def test_break(self):
+        breakpoint_amount = len(gdb.breakpoints())
+        gdb.execute('cy break codefile.spam')
+        
+        self.assertEqual(len(gdb.breakpoints()), breakpoint_amount + 1)
+        bp = gdb.breakpoints()[-1]
+        self.assertEqual(bp.type, gdb.BP_BREAKPOINT)
+        assert self.spam_func.cname in bp.location
+        assert bp.enabled
+    
+    def test_python_break(self):
+        gdb.execute('cy break -p join')
+        assert 'def join(' in gdb.execute('cy run', to_string=True)
+
+
+class TestKilled(DebugTestCase):
+    
+    def test_abort(self):
+        gdb.execute("set args -c 'import os; os.abort()'")
+        output = gdb.execute('cy run', to_string=True)
+        assert 'abort' in output.lower()
+
+class DebugStepperTestCase(DebugTestCase):
+    
+    def step(self, varnames_and_values, source_line=None, lineno=None):
+        gdb.execute(self.command)
+        for varname, value in varnames_and_values:
+            self.assertEqual(self.read_var(varname), value, self.local_info())
+        
+        self.lineno_equals(source_line, lineno)
+
+
+class TestStep(DebugStepperTestCase):
+    """
+    Test stepping. Stepping happens in the code found in 
+    Cython/Debugger/Tests/codefile.
+    """
+    
+    def test_cython_step(self):
+        gdb.execute('cy break codefile.spam')
+        
+        gdb.execute('run', to_string=True)
+        self.lineno_equals('def spam(a=0):')
+        
+        gdb.execute('cy step', to_string=True)
+        self.lineno_equals('b = c = d = 0')
+        
+        self.command = 'cy step'
+        self.step([('b', 0)], source_line='b = 1')
+        self.step([('b', 1), ('c', 0)], source_line='c = 2')
+        self.step([('c', 2)], source_line='int(10)')
+        self.step([], source_line='puts("spam")')
+        
+        gdb.execute('cont', to_string=True)
+        self.assertEqual(len(gdb.inferiors()), 1)
+        self.assertEqual(gdb.inferiors()[0].pid, 0)
+    
+    def test_c_step(self):
+        self.break_and_run('some_c_function()')
+        gdb.execute('cy step', to_string=True)
+        self.assertEqual(gdb.selected_frame().name(), 'some_c_function')
+    
+    def test_python_step(self):
+        self.break_and_run('os.path.join("foo", "bar")')
+        
+        result = gdb.execute('cy step', to_string=True)
+        
+        curframe = gdb.selected_frame()
+        self.assertEqual(curframe.name(), 'PyEval_EvalFrameEx')
+        
+        pyframe = libpython.Frame(curframe).get_pyop()
+        self.assertEqual(str(pyframe.co_name), 'join')
+        assert re.match(r'\d+    def join\(', result), result
+
+class TestNext(DebugStepperTestCase):
+    
+    def test_cython_next(self):
+        self.break_and_run('c = 2')
+
+        lines = (
+            'int(10)',
+            'puts("spam")',
+            'os.path.join("foo", "bar")',
+            'some_c_function()',
+        )
+
+        for line in lines:
+            gdb.execute('cy next')
+            self.lineno_equals(line)
+
+
+class TestLocalsGlobals(DebugTestCase):
+    
+    def test_locals(self):
+        self.break_and_run('int(10)')
+        
+        result = gdb.execute('cy locals', to_string=True)
+        assert 'a = 0', repr(result)
+        assert 'b = (int) 1', result
+        assert 'c = (int) 2' in result, repr(result)
+    
+    def test_globals(self):
+        self.break_and_run('int(10)')
+        
+        result = gdb.execute('cy globals', to_string=True)
+        assert '__name__ ' in result, repr(result)
+        assert '__doc__ ' in result, repr(result)
+        assert 'os ' in result, repr(result)
+        assert 'c_var ' in result, repr(result)
+        assert 'python_var ' in result, repr(result)
+
+
+class TestBacktrace(DebugTestCase):
+    
+    def test_backtrace(self):
+        libcython.parameters.colorize_code.value = False
+        
+        self.break_and_run('os.path.join("foo", "bar")')
+        result = gdb.execute('cy bt', to_string=True)
+        
+        _debug(libpython.execute, libpython._execute, gdb.execute)
+        _debug(gdb.execute('cy list', to_string=True))
+        _debug(repr(result))
+        
+        assert re.search(r'\#\d+ *0x.* in spam\(\) at .*codefile\.pyx:22', 
+                         result), result
+        assert 'os.path.join("foo", "bar")' in result, result
+        
+        gdb.execute("cy step")
+        
+        gdb.execute('cy bt')
+        result = gdb.execute('cy bt -a', to_string=True)
+        assert re.search(r'\#0 *0x.* in main\(\) at', result), result
+
+
+class TestFunctions(DebugTestCase):
+    
+    def test_functions(self):
+        self.break_and_run('c = 2')
+        result = gdb.execute('print $cy_cname("b")', to_string=True)
+        assert re.search('__pyx_.*b', result), result
+        
+        result = gdb.execute('print $cy_lineno()', to_string=True)
+        supposed_lineno = test_libcython.source_to_lineno['c = 2']
+        assert str(supposed_lineno) in result, (supposed_lineno, result)
+        
+        result = gdb.execute('print $cy_cvalue("b")', to_string=True)
+        assert '= 1' in result
+        
+
+class TestPrint(DebugTestCase):
+    
+    def test_print(self):
+        self.break_and_run('c = 2')
+        result = gdb.execute('cy print b', to_string=True)
+        self.assertEqual('b = (int) 1\n', result)
+
+
+class TestUpDown(DebugTestCase):
+
+    def test_updown(self):
+        self.break_and_run('os.path.join("foo", "bar")')
+        gdb.execute('cy step')
+        self.assertRaises(RuntimeError, gdb.execute, 'cy down')
+        
+        result = gdb.execute('cy up', to_string=True)
+        assert 'spam()' in result
+        assert 'os.path.join("foo", "bar")' in result
+
+
+class TestExec(DebugTestCase):
+    
+    def setUp(self):
+        super(TestExec, self).setUp()
+        self.fd, self.tmpfilename = tempfile.mkstemp()
+        self.tmpfile = os.fdopen(self.fd, 'r+')
+        
+    def tearDown(self):
+        super(TestExec, self).tearDown()
+        
+        try:
+            self.tmpfile.close()
+        finally:
+            os.remove(self.tmpfilename)
+    
+    def eval_command(self, command):
+        gdb.execute('cy exec open(%r, "w").write(str(%s))' % 
+                                                (self.tmpfilename, command))
+        return self.tmpfile.read().strip()
+    
+    def test_cython_exec(self):
+        self.break_and_run('os.path.join("foo", "bar")')
+        
+        # test normal behaviour
+        self.assertEqual("[0]", self.eval_command('[a]'))
+        
+        # test multiline code
+        result = gdb.execute(textwrap.dedent('''\
+            cy exec
+            pass
+            
+            "nothing"
+            end
+            '''))
+        result = self.tmpfile.read().rstrip()
+        self.assertEqual('', result)
+    
+    def test_python_exec(self):
+        self.break_and_run('os.path.join("foo", "bar")')
+        gdb.execute('cy step')
+        
+        gdb.execute('cy exec some_random_var = 14')
+        self.assertEqual('14', self.eval_command('some_random_var'))
+
+
+_do_debug = os.environ.get('CYTHON_GDB_DEBUG')
+if _do_debug:
+    _debug_file = open('/dev/tty', 'w')
+
+def _debug(*messages):
+    if _do_debug:
+        messages = itertools.chain([sys._getframe(1).f_code.co_name], 
+                                   messages)
+        _debug_file.write(' '.join(str(msg) for msg in messages) + '\n')
+
+def _main():
+    try:
+        gdb.lookup_type('PyModuleObject')
+    except RuntimeError:
+        msg = ("Unable to run tests, Python was not compiled with "
+                "debugging information. Either compile python with "
+                "-g or get a debug build (configure with --with-pydebug).")
+        warnings.warn(msg)
+        os._exit(1)
+    else:
+        m = __import__(__name__, fromlist=[''])
+        tests = inspect.getmembers(m, inspect.isclass)
+        
+        # test_support.run_unittest(tests)
+        
+        test_loader = unittest.TestLoader()
+        suite = unittest.TestSuite(
+            [test_loader.loadTestsFromTestCase(cls) for name, cls in tests])
+        
+        result = unittest.TextTestRunner(verbosity=1).run(suite)
+        if not result.wasSuccessful():
+            os._exit(1)
+
+def main(trace_code=False):
+    if trace_code:
+        tracer = trace.Trace(count=False, trace=True, outfile=sys.stderr,
+                            ignoredirs=[sys.prefix, sys.exec_prefix])
+        tracer.runfunc(_main)
+    else:
+        _main()
+
+main()
\ No newline at end of file

Cython/Debugger/libcython.py

+"""
+GDB extension that adds Cython support.
+"""
+
+from __future__ import with_statement
+
+import os
+import sys
+import textwrap
+import operator
+import traceback
+import functools
+import itertools
+import collections
+
+import gdb
+
+try:
+  from lxml import etree
+  have_lxml = True
+except ImportError:
+    have_lxml = False
+    try:
+        # Python 2.5
+        from xml.etree import cElementTree as etree
+    except ImportError:
+        try:
+            # Python 2.5
+            from xml.etree import ElementTree as etree
+        except ImportError:
+            try:
+                # normal cElementTree install
+                import cElementTree as etree
+            except ImportError:
+                # normal ElementTree install
+                import elementtree.ElementTree as etree
+
+try:
+    import pygments.lexers
+    import pygments.formatters
+except ImportError:
+    pygments = None
+    sys.stderr.write("Install pygments for colorized source code.\n")
+
+if hasattr(gdb, 'string_to_argv'):
+    from gdb import string_to_argv
+else:
+    from shlex import split as string_to_argv
+
+from Cython.Debugger import libpython
+
+# C or Python type
+CObject = 'CObject'
+PythonObject = 'PythonObject'
+
+_data_types = dict(CObject=CObject, PythonObject=PythonObject)
+_filesystemencoding = sys.getfilesystemencoding() or 'UTF-8'
+
+# decorators
+
+def dont_suppress_errors(function):
+    "*sigh*, readline"
+    @functools.wraps(function)
+    def wrapper(*args, **kwargs):
+        try:
+            return function(*args, **kwargs)
+        except Exception:
+            traceback.print_exc()
+            raise
+    
+    return wrapper
+
+def default_selected_gdb_frame(err=True):
+    def decorator(function):
+        @functools.wraps(function)
+        def wrapper(self, frame=None, *args, **kwargs):
+            try:
+                frame = frame or gdb.selected_frame()
+            except RuntimeError:
+                raise gdb.GdbError("No frame is currently selected.")
+                
+            if err and frame.name() is None:
+                raise NoFunctionNameInFrameError()
+    
+            return function(self, frame, *args, **kwargs)
+        return wrapper
+    return decorator
+
+def require_cython_frame(function):
+    @functools.wraps(function)
+    @require_running_program
+    def wrapper(self, *args, **kwargs):
+        frame = kwargs.get('frame') or gdb.selected_frame()
+        if not self.is_cython_function(frame):
+            raise gdb.GdbError('Selected frame does not correspond with a '
+                               'Cython function we know about.')
+        return function(self, *args, **kwargs)
+    return wrapper 
+
+def dispatch_on_frame(c_command, python_command=None):
+    def decorator(function):
+        @functools.wraps(function)
+        def wrapper(self, *args, **kwargs):
+            is_cy = self.is_cython_function()
+            is_py = self.is_python_function()
+            
+            if is_cy or (is_py and not python_command):
+                function(self, *args, **kwargs)
+            elif is_py:
+                gdb.execute(python_command)
+            elif self.is_relevant_function():
+                gdb.execute(c_command)
+            else:
+                raise gdb.GdbError("Not a function cygdb knows about. "
+                                   "Use the normal GDB commands instead.")
+        
+        return wrapper
+    return decorator
+
+def require_running_program(function):
+    @functools.wraps(function)
+    def wrapper(*args, **kwargs):
+        try:
+            gdb.selected_frame()
+        except RuntimeError:
+            raise gdb.GdbError("No frame is currently selected.")
+        
+        return function(*args, **kwargs)
+    return wrapper
+    
+
+def gdb_function_value_to_unicode(function):
+    @functools.wraps(function)
+    def wrapper(self, string, *args, **kwargs):
+        if isinstance(string, gdb.Value):
+            string = string.string()
+
+        return function(self, string, *args, **kwargs)
+    return wrapper
+
+
+# Classes that represent the debug information
+# Don't rename the parameters of these classes, they come directly from the XML
+
+class CythonModule(object):
+    def __init__(self, module_name, filename, c_filename):
+        self.name = module_name
+        self.filename = filename
+        self.c_filename = c_filename
+        self.globals = {}
+        # {cython_lineno: min(c_linenos)}
+        self.lineno_cy2c = {}
+        # {c_lineno: cython_lineno}
+        self.lineno_c2cy = {}
+        self.functions = {}
+        
+    def qualified_name(self, varname):
+        return '.'.join(self.name, varname)
+
+class CythonVariable(object):
+
+    def __init__(self, name, cname, qualified_name, type, lineno):
+        self.name = name
+        self.cname = cname
+        self.qualified_name = qualified_name
+        self.type = type
+        self.lineno = int(lineno)
+
+class CythonFunction(CythonVariable):
+    def __init__(self, 
+                 module, 
+                 name, 
+                 cname, 
+                 pf_cname,
+                 qualified_name, 
+                 lineno, 
+                 type=CObject):
+        super(CythonFunction, self).__init__(name, 
+                                             cname, 
+                                             qualified_name, 
+                                             type,
+                                             lineno)
+        self.module = module
+        self.pf_cname = pf_cname
+        self.locals = {}
+        self.arguments = []
+        self.step_into_functions = set()
+
+
+# General purpose classes
+
+class CythonBase(object):
+    
+    @default_selected_gdb_frame(err=False)
+    def is_cython_function(self, frame):
+        return frame.name() in self.cy.functions_by_cname
+
+    @default_selected_gdb_frame(err=False)
+    def is_python_function(self, frame):
+        """
+        Tells if a frame is associated with a Python function.
+        If we can't read the Python frame information, don't regard it as such.
+        """
+        if frame.name() == 'PyEval_EvalFrameEx':
+            pyframe = libpython.Frame(frame).get_pyop()
+            return pyframe and not pyframe.is_optimized_out()
+        return False
+        
+    @default_selected_gdb_frame()
+    def get_c_function_name(self, frame):
+        return frame.name()
+
+    @default_selected_gdb_frame()
+    def get_c_lineno(self, frame):
+        return frame.find_sal().line
+    
+    @default_selected_gdb_frame()
+    def get_cython_function(self, frame):
+        result = self.cy.functions_by_cname.get(frame.name())
+        if result is None:
+            raise NoCythonFunctionInFrameError()
+            
+        return result
+    
+    @default_selected_gdb_frame()
+    def get_cython_lineno(self, frame):
+        """
+        Get the current Cython line number. Returns 0 if there is no 
+        correspondence between the C and Cython code.
+        """
+        cyfunc = self.get_cython_function(frame)
+        return cyfunc.module.lineno_c2cy.get(self.get_c_lineno(frame), 0)
+    
+    @default_selected_gdb_frame()
+    def get_source_desc(self, frame):
+        filename = lineno = lexer = None
+        if self.is_cython_function(frame):
+            filename = self.get_cython_function(frame).module.filename
+            lineno = self.get_cython_lineno(frame)
+            if pygments:
+                lexer = pygments.lexers.CythonLexer(stripall=False)
+        elif self.is_python_function(frame):
+            pyframeobject = libpython.Frame(frame).get_pyop()
+
+            if not pyframeobject:
+                raise gdb.GdbError('Unable to read information on python frame')
+
+            filename = pyframeobject.filename()
+            lineno = pyframeobject.current_line_num()
+            
+            if pygments:
+                lexer = pygments.lexers.PythonLexer(stripall=False)
+        else:
+            symbol_and_line_obj = frame.find_sal()
+            if not symbol_and_line_obj or not symbol_and_line_obj.symtab:
+                filename = None
+                lineno = 0
+            else:
+                filename = symbol_and_line_obj.symtab.filename
+                lineno = symbol_and_line_obj.line
+                if pygments:
+                    lexer = pygments.lexers.CLexer(stripall=False)
+            
+        return SourceFileDescriptor(filename, lexer), lineno
+
+    @default_selected_gdb_frame()
+    def get_source_line(self, frame):
+        source_desc, lineno = self.get_source_desc()
+        return source_desc.get_source(lineno)
+    
+    @default_selected_gdb_frame()
+    def is_relevant_function(self, frame):
+        """
+        returns whether we care about a frame on the user-level when debugging
+        Cython code
+        """
+        name = frame.name()
+        older_frame = frame.older()
+        if self.is_cython_function(frame) or self.is_python_function(frame):
+            return True
+        elif older_frame and self.is_cython_function(older_frame):
+            # direct C function call from a Cython function
+            cython_func = self.get_cython_function(older_frame)
+            return name in cython_func.step_into_functions
+
+        return False
+    
+    @default_selected_gdb_frame(err=False)
+    def print_stackframe(self, frame, index, is_c=False):
+        """
+        Print a C, Cython or Python stack frame and the line of source code
+        if available.
+        """
+        # do this to prevent the require_cython_frame decorator from
+        # raising GdbError when calling self.cy.cy_cvalue.invoke()
+        selected_frame = gdb.selected_frame()
+        frame.select()
+        
+        try:
+            source_desc, lineno = self.get_source_desc(frame)
+        except NoFunctionNameInFrameError:
+            print '#%-2d Unknown Frame (compile with -g)' % index
+            return
+
+        if not is_c and self.is_python_function(frame):
+            pyframe = libpython.Frame(frame).get_pyop()
+            if pyframe is None or pyframe.is_optimized_out():
+                # print this python function as a C function
+                return self.print_stackframe(frame, index, is_c=True)
+            
+            func_name = pyframe.co_name
+            func_cname = 'PyEval_EvalFrameEx'
+            func_args = []
+        elif self.is_cython_function(frame):
+            cyfunc = self.get_cython_function(frame)
+            f = lambda arg: self.cy.cy_cvalue.invoke(arg, frame=frame)
+            
+            func_name = cyfunc.name
+            func_cname = cyfunc.cname
+            func_args = [] # [(arg, f(arg)) for arg in cyfunc.arguments]
+        else:
+            source_desc, lineno = self.get_source_desc(frame)
+            func_name = frame.name()
+            func_cname = func_name
+            func_args = []
+        
+        try:
+            gdb_value = gdb.parse_and_eval(func_cname)
+        except RuntimeError:
+            func_address = 0
+        else:
+            # Seriously? Why is the address not an int?
+            func_address = int(str(gdb_value.address).split()[0], 0)
+        
+        a = ', '.join('%s=%s' % (name, val) for name, val in func_args)
+        print '#%-2d 0x%016x in %s(%s)' % (index, func_address, func_name, a),
+            
+        if source_desc.filename is not None:
+            print 'at %s:%s' % (source_desc.filename, lineno),
+        
+        print
+            
+        try:
+            print '    ' + source_desc.get_source(lineno)
+        except gdb.GdbError:
+            pass
+        
+        selected_frame.select()
+    
+    def get_remote_cython_globals_dict(self):
+        m = gdb.parse_and_eval('__pyx_m')
+        
+        try:
+            PyModuleObject = gdb.lookup_type('PyModuleObject')
+        except RuntimeError:
+            raise gdb.GdbError(textwrap.dedent("""\
+                Unable to lookup type PyModuleObject, did you compile python 
+                with debugging support (-g)?"""))
+            
+        m = m.cast(PyModuleObject.pointer())
+        return m['md_dict']
+        
+    
+    def get_cython_globals_dict(self):
+        """
+        Get the Cython globals dict where the remote names are turned into
+        local strings.
+        """
+        remote_dict = self.get_remote_cython_globals_dict()
+        pyobject_dict = libpython.PyObjectPtr.from_pyobject_ptr(remote_dict)
+        
+        result = {}
+        seen = set()
+        for k, v in pyobject_dict.iteritems():
+            result[k.proxyval(seen)] = v
+            
+        return result
+
+    def print_gdb_value(self, name, value, max_name_length=None, prefix=''):
+        if libpython.pretty_printer_lookup(value):
+            typename = ''
+        else:
+            typename = '(%s) ' % (value.type,)
+                
+        if max_name_length is None:
+            print '%s%s = %s%s' % (prefix, name, typename, value)
+        else:
+            print '%s%-*s = %s%s' % (prefix, max_name_length, name, typename, 
+                                     value)
+
+    def is_initialized(self, cython_func, local_name):
+        cur_lineno = self.get_cython_lineno()
+        return (local_name in cython_func.arguments or
+                (local_name in cython_func.locals and
+                 cur_lineno > cython_func.locals[local_name].lineno))
+
+class SourceFileDescriptor(object):
+    def __init__(self, filename, lexer, formatter=None):
+        self.filename = filename
+        self.lexer = lexer
+        self.formatter = formatter
+
+    def valid(self):
+        return self.filename is not None
+
+    def lex(self, code):
+        if pygments and self.lexer and parameters.colorize_code:
+            bg = parameters.terminal_background.value
+            if self.formatter is None:
+                formatter = pygments.formatters.TerminalFormatter(bg=bg)
+            else:
+                formatter = self.formatter
+
+            return pygments.highlight(code, self.lexer, formatter)
+
+        return code
+
+    def _get_source(self, start, stop, lex_source, mark_line, lex_entire):
+        with open(self.filename) as f:
+            # to provide "correct" colouring, the entire code needs to be
+            # lexed. However, this makes a lot of things terribly slow, so
+            # we decide not to. Besides, it's unlikely to matter.
+            
+            if lex_source and lex_entire:
+                f = self.lex(f.read()).splitlines()
+            
+            slice = itertools.islice(f, start - 1, stop - 1)
+            
+            for idx, line in enumerate(slice):
+                if start + idx == mark_line:
+                    prefix = '>'
+                else:
+                    prefix = ' '
+                
+                if lex_source and not lex_entire:
+                    line = self.lex(line)
+
+                yield '%s %4d    %s' % (prefix, start + idx, line.rstrip())
+
+    def get_source(self, start, stop=None, lex_source=True, mark_line=0, 
+                   lex_entire=False):
+        exc = gdb.GdbError('Unable to retrieve source code')
+        
+        if not self.filename:
+            raise exc
+        
+        start = max(start, 1)
+        if stop is None:
+            stop = start + 1
+
+        try:
+            return '\n'.join(
+                self._get_source(start, stop, lex_source, mark_line, lex_entire))
+        except IOError:
+            raise exc
+
+
+# Errors
+
+class CyGDBError(gdb.GdbError):
+    """
+    Base class for Cython-command related erorrs
+    """
+    
+    def __init__(self, *args):
+        args = args or (self.msg,)
+        super(CyGDBError, self).__init__(*args)
+    
+class NoCythonFunctionInFrameError(CyGDBError):
+    """
+    raised when the user requests the current cython function, which is 
+    unavailable
+    """
+    msg = "Current function is a function cygdb doesn't know about"
+
+class NoFunctionNameInFrameError(NoCythonFunctionInFrameError):
+    """
+    raised when the name of the C function could not be determined 
+    in the current C stack frame
+    """
+    msg = ('C function name could not be determined in the current C stack '
+           'frame')
+
+
+# Parameters
+
+class CythonParameter(gdb.Parameter):
+    """
+    Base class for cython parameters
+    """
+    
+    def __init__(self, name, command_class, parameter_class, default=None):
+        self.show_doc = self.set_doc = self.__class__.__doc__
+        super(CythonParameter, self).__init__(name, command_class, 
+                                              parameter_class)
+        if default is not None:
+            self.value = default
+   
+    def __nonzero__(self):
+        return bool(self.value)
+    
+    __bool__ = __nonzero__ # python 3
+
+class CompleteUnqualifiedFunctionNames(CythonParameter):
+    """
+    Have 'cy break' complete unqualified function or method names.
+    """ 
+
+class ColorizeSourceCode(CythonParameter):
+    """
+    Tell cygdb whether to colorize source code.
+    """
+
+class TerminalBackground(CythonParameter):
+    """
+    Tell cygdb about the user's terminal background (light or dark).
+    """
+
+class CythonParameters(object):
+    """
+    Simple container class that might get more functionality in the distant
+    future (mostly to remind us that we're dealing with parameters).
+    """
+    
+    def __init__(self):
+        self.complete_unqualified = CompleteUnqualifiedFunctionNames(
+            'cy_complete_unqualified',
+            gdb.COMMAND_BREAKPOINTS,
+            gdb.PARAM_BOOLEAN,
+            True)
+        self.colorize_code = ColorizeSourceCode(
+            'cy_colorize_code',
+            gdb.COMMAND_FILES,
+            gdb.PARAM_BOOLEAN,
+            True)
+        self.terminal_background = TerminalBackground(
+            'cy_terminal_background_color',
+            gdb.COMMAND_FILES,
+            gdb.PARAM_STRING,
+            "dark")
+        
+parameters = CythonParameters()
+
+
+# Commands
+
+class CythonCommand(gdb.Command, CythonBase):
+    """
+    Base class for Cython commands
+    """
+    
+    command_class = gdb.COMMAND_NONE
+    
+    @classmethod
+    def _register(cls, clsname, args, kwargs):
+        if not hasattr(cls, 'completer_class'):
+            return cls(clsname, cls.command_class, *args, **kwargs)
+        else:
+            return cls(clsname, cls.command_class, cls.completer_class, 
+                       *args, **kwargs)
+    
+    @classmethod
+    def register(cls, *args, **kwargs):
+        alias = getattr(cls, 'alias', None)
+        if alias:
+            cls._register(cls.alias, args, kwargs)
+            
+        return cls._register(cls.name, args, kwargs)
+
+
+class CyCy(CythonCommand):
+    """
+    Invoke a Cython command. Available commands are:
+        
+        cy import
+        cy break
+        cy step
+        cy next
+        cy run
+        cy cont
+        cy finish
+        cy up
+        cy down
+        cy select
+        cy bt / cy backtrace
+        cy list
+        cy print
+        cy locals
+        cy globals
+        cy exec
+    """
+    
+    name = 'cy'
+    command_class = gdb.COMMAND_NONE
+    completer_class = gdb.COMPLETE_COMMAND
+    
+    def __init__(self, name, command_class, completer_class):
+        # keep the signature 2.5 compatible (i.e. do not use f(*a, k=v)
+        super(CythonCommand, self).__init__(name, command_class, 
+                                            completer_class, prefix=True)
+        
+        commands = dict(
+            import_ = CyImport.register(),
+            break_ = CyBreak.register(),
+            step = CyStep.register(),
+            next = CyNext.register(),
+            run = CyRun.register(),
+            cont = CyCont.register(),
+            finish = CyFinish.register(),
+            up = CyUp.register(),
+            down = CyDown.register(),
+            select = CySelect.register(),
+            bt = CyBacktrace.register(),
+            list = CyList.register(),
+            print_ = CyPrint.register(),
+            locals = CyLocals.register(),
+            globals = CyGlobals.register(),
+            exec_ = libpython.FixGdbCommand('cy exec', '-cy-exec'),
+            _exec = CyExec.register(),
+            cy_cname = CyCName('cy_cname'),
+            cy_cvalue = CyCValue('cy_cvalue'),
+            cy_lineno = CyLine('cy_lineno'),
+        )
+            
+        for command_name, command in commands.iteritems():
+            command.cy = self
+            setattr(self, command_name, command)
+        
+        self.cy = self
+        
+        # Cython module namespace
+        self.cython_namespace = {}
+        
+        # maps (unique) qualified function names (e.g. 
+        # cythonmodule.ClassName.method_name) to the CythonFunction object
+        self.functions_by_qualified_name = {}
+        
+        # unique cnames of Cython functions
+        self.functions_by_cname = {}
+        
+        # map function names like method_name to a list of all such 
+        # CythonFunction objects
+        self.functions_by_name = collections.defaultdict(list)
+
+
+class CyImport(CythonCommand):
+    """
+    Import debug information outputted by the Cython compiler
+    Example: cy import FILE...
+    """
+    
+    name = 'cy import'
+    command_class = gdb.COMMAND_STATUS
+    completer_class = gdb.COMPLETE_FILENAME
+    
+    def invoke(self, args, from_tty):
+        args = args.encode(_filesystemencoding)
+        for arg in string_to_argv(args):
+            try:
+                f = open(arg)
+            except OSError, e:
+                raise gdb.GdbError('Unable to open file %r: %s' % 
+                                                (args, e.args[1]))
+            
+            t = etree.parse(f)
+            
+            for module in t.getroot():
+                cython_module = CythonModule(**module.attrib)
+                self.cy.cython_namespace[cython_module.name] = cython_module
+                
+                for variable in module.find('Globals'):
+                    d = variable.attrib
+                    cython_module.globals[d['name']] = CythonVariable(**d)
+                
+                for function in module.find('Functions'):
+                    cython_function = CythonFunction(module=cython_module, 
+                                                     **function.attrib)
+
+                    # update the global function mappings
+                    name = cython_function.name
+                    qname = cython_function.qualified_name
+                    
+                    self.cy.functions_by_name[name].append(cython_function)
+                    self.cy.functions_by_qualified_name[
+                        cython_function.qualified_name] = cython_function
+                    self.cy.functions_by_cname[
+                        cython_function.cname] = cython_function
+                    
+                    d = cython_module.functions[qname] = cython_function
+                    
+                    for local in function.find('Locals'):
+                        d = local.attrib
+                        cython_function.locals[d['name']] = CythonVariable(**d)
+
+                    for step_into_func in function.find('StepIntoFunctions'):
+                        d = step_into_func.attrib
+                        cython_function.step_into_functions.add(d['name'])
+                    
+                    cython_function.arguments.extend(
+                        funcarg.tag for funcarg in function.find('Arguments'))
+
+                for marker in module.find('LineNumberMapping'):
+                    cython_lineno = int(marker.attrib['cython_lineno'])
+                    c_linenos = map(int, marker.attrib['c_linenos'].split())
+                    cython_module.lineno_cy2c[cython_lineno] = min(c_linenos)
+                    for c_lineno in c_linenos:
+                        cython_module.lineno_c2cy[c_lineno] = cython_lineno
+
+        self.cy.step.init_breakpoints()
+
+
+class CyBreak(CythonCommand):
+    """
+    Set a breakpoint for Cython code using Cython qualified name notation, e.g.:
+        
+        cy break cython_modulename.ClassName.method_name...
+    
+    or normal notation:
+        
+        cy break function_or_method_name...
+    
+    or for a line number:
+    
+        cy break cython_module:lineno...
+    
+    Set a Python breakpoint:
+        Break on any function or method named 'func' in module 'modname'
+            
+            cy break -p modname.func...
+        
+        Break on any function or method named 'func'
+            
+            cy break -p func...
+    """
+    
+    name = 'cy break'
+    command_class = gdb.COMMAND_BREAKPOINTS
+    
+    def _break_pyx(self, name):
+        modulename, _, lineno = name.partition(':')
+        lineno = int(lineno)
+        if modulename:
+            cython_module = self.cy.cython_namespace[modulename]
+        else:
+            cython_module = self.get_cython_function().module
+
+        if lineno in cython_module.lineno_cy2c:
+            c_lineno = cython_module.lineno_cy2c[lineno]
+            breakpoint = '%s:%s' % (cython_module.c_filename, c_lineno)
+            gdb.execute('break ' + breakpoint)
+        else:
+            raise GdbError("Not a valid line number. "
+                           "Does it contain actual code?")
+    
+    def _break_funcname(self, funcname):
+        func = self.cy.functions_by_qualified_name.get(funcname)
+        break_funcs = [func]
+        
+        if not func:
+            funcs = self.cy.functions_by_name.get(funcname)
+            if not funcs:
+                gdb.execute('break ' + funcname)
+                return
+                
+            if len(funcs) > 1:
+                # multiple functions, let the user pick one
+                print 'There are multiple such functions:'
+                for idx, func in enumerate(funcs):
+                    print '%3d) %s' % (idx, func.qualified_name)
+                
+                while True:
+                    try:
+                        result = raw_input(
+                            "Select a function, press 'a' for all "
+                            "functions or press 'q' or '^D' to quit: ")
+                    except EOFError:
+                        return
+                    else:
+                        if result.lower() == 'q':
+                            return
+                        elif result.lower() == 'a':
+                            break_funcs = funcs
+                            break
+                        elif (result.isdigit() and 
+                            0 <= int(result) < len(funcs)):
+                            break_funcs = [funcs[int(result)]]
+                            break
+                        else:
+                            print 'Not understood...'
+            else:
+                break_funcs = [funcs[0]]
+        
+        for func in break_funcs:
+            gdb.execute('break %s' % func.cname)
+            if func.pf_cname:
+                gdb.execute('break %s' % func.pf_cname)
+    
+    def invoke(self, function_names, from_tty):
+        argv = string_to_argv(function_names.encode('UTF-8'))
+        if function_names.startswith('-p'):
+            argv = argv[1:]
+            python_breakpoints = True
+        else:
+            python_breakpoints = False
+        
+        for funcname in argv:
+            if python_breakpoints:
+                gdb.execute('py-break %s' % funcname)
+            elif ':' in funcname:
+                self._break_pyx(funcname)
+            else:
+                self._break_funcname(funcname)
+    
+    @dont_suppress_errors
+    def complete(self, text, word):
+        names = self.cy.functions_by_qualified_name
+        if parameters.complete_unqualified:
+            names = itertools.chain(names, self.cy.functions_by_name)
+
+        words = text.strip().split()
+        if words and '.' in words[-1]:
+            lastword = words[-1]
+            compl = [n for n in self.cy.functions_by_qualified_name 
+                           if n.startswith(lastword)]
+        else:
+            seen = set(text[:-len(word)].split())
+            return [n for n in names if n.startswith(word) and n not in seen]
+        
+        if len(lastword) > len(word):
+            # readline sees something (e.g. a '.') as a word boundary, so don't
+            # "recomplete" this prefix
+            strip_prefix_length = len(lastword) - len(word)
+            compl = [n[strip_prefix_length:] for n in compl]
+            
+        return compl
+
+
+class CythonCodeStepper(CythonCommand, libpython.GenericCodeStepper):
+    """
+    Base class for CyStep and CyNext. It implements the interface dictated by
+    libpython.GenericCodeStepper.
+    """
+    
+    def lineno(self, frame):
+        # Take care of the Python and Cython levels. We need to care for both
+        # as we can't simply dispath to 'py-step', since that would work for
+        # stepping through Python code, but it would not step back into Cython-
+        # related code. The C level should be dispatched to the 'step' command.
+        if self.is_cython_function(frame):
+            return self.get_cython_lineno(frame)
+        else:
+            return libpython.py_step.lineno(frame)
+    
+    def get_source_line(self, frame):
+        try:
+            line = super(CythonCodeStepper, self).get_source_line(frame)
+        except gdb.GdbError:
+            return None
+        else:
+            return line.strip() or None
+
+    @classmethod
+    def register(cls):
+        return cls(cls.name, stepinto=getattr(cls, 'stepinto', False))
+
+    def runtime_break_functions(self):
+        if self.is_cython_function():
+            return self.get_cython_function().step_into_functions
+    
+    def static_break_functions(self):
+        result = ['PyEval_EvalFrameEx']
+        result.extend(self.cy.functions_by_cname)
+        return result
+
+    def invoke(self, args, from_tty):
+        if not self.is_cython_function() and not self.is_python_function():
+            if self.stepinto:
+                command = 'step'
+            else:
+                command = 'next'
+                
+            self.finish_executing(gdb.execute(command, to_string=True))
+        else:
+            self.step()
+
+
+class CyStep(CythonCodeStepper):
+    "Step through Cython, Python or C code."
+    
+    name = 'cy step'
+    stepinto = True
+
+
+class CyNext(CythonCodeStepper):
+    "Step-over Python code."
+
+    name = 'cy next'
+    stepinto = False
+
+
+class CyRun(CythonCodeStepper):
+    """
+    Run a Cython program. This is like the 'run' command, except that it 
+    displays Cython or Python source lines as well
+    """
+    
+    name = 'cy run'
+    
+    invoke = CythonCodeStepper.run
+
+
+class CyCont(CyRun):
+    """
+    Continue a Cython program. This is like the 'run' command, except that it 
+    displays Cython or Python source lines as well.
+    """
+    
+    name = 'cy cont'
+    invoke = CythonCodeStepper.cont
+
+
+class CyFinish(CyRun):
+    """
+    Execute until the function returns.
+    """
+    name = 'cy finish'
+
+    invoke = CythonCodeStepper.finish
+
+
+class CyUp(CythonCommand):
+    """
+    Go up a Cython, Python or relevant C frame.
+    """
+    name = 'cy up'
+    _command = 'up'
+    
+    def invoke(self, *args):
+        try:
+            gdb.execute(self._command, to_string=True)
+            while not self.is_relevant_function(gdb.selected_frame()):
+                gdb.execute(self._command, to_string=True)
+        except RuntimeError, e:
+            raise gdb.GdbError(*e.args)
+        
+        frame = gdb.selected_frame()
+        index = 0
+        while frame:
+            frame = frame.older()
+            index += 1
+            
+        self.print_stackframe(index=index - 1)
+
+
+class CyDown(CyUp):
+    """
+    Go down a Cython, Python or relevant C frame.
+    """
+    
+    name = 'cy down'
+    _command = 'down'
+
+
+class CySelect(CythonCodeStepper):
+    """
+    Select a frame. Use frame numbers as listed in `cy backtrace`.
+    This command is useful because `cy backtrace` prints a reversed backtrace.
+    """
+    
+    name = 'cy select'
+    
+    def invoke(self, stackno, from_tty):
+        try:
+            stackno = int(stackno)
+        except ValueError:
+            raise gdb.GdbError("Not a valid number: %r" % (stackno,))
+        
+        frame = gdb.selected_frame()
+        while frame.newer():
+            frame = frame.newer()
+        
+        stackdepth = self._stackdepth(frame)
+        
+        try:
+            gdb.execute('select %d' % (stackdepth - stackno - 1,))
+        except RuntimeError, e:
+            raise gdb.GdbError(*e.args)
+
+
+class CyBacktrace(CythonCommand):
+    'Print the Cython stack'
+    
+    name = 'cy bt'
+    alias = 'cy backtrace'
+    command_class = gdb.COMMAND_STACK
+    completer_class = gdb.COMPLETE_NONE
+    
+    @require_running_program
+    def invoke(self, args, from_tty):
+        # get the first frame
+        selected_frame = frame = gdb.selected_frame()
+        while frame.older():
+            frame = frame.older()
+        
+        print_all = args == '-a'
+        
+        index = 0
+        while frame:
+            is_c = False
+            
+            is_relevant = False
+            try:
+                is_relevant = self.is_relevant_function(frame)
+            except CyGDBError:
+                pass
+                
+            if print_all or is_relevant:
+                self.print_stackframe(frame, index)
+            
+            index += 1
+            frame = frame.newer()
+        
+        selected_frame.select()
+
+
+class CyList(CythonCommand):
+    """
+    List Cython source code. To disable to customize colouring see the cy_*
+    parameters.
+    """
+    
+    name = 'cy list'
+    command_class = gdb.COMMAND_FILES
+    completer_class = gdb.COMPLETE_NONE
+    
+    @dispatch_on_frame(c_command='list')
+    def invoke(self, _, from_tty):
+        sd, lineno = self.get_source_desc()
+        source = sd.get_source(lineno - 5, lineno + 5, mark_line=lineno, 
+                               lex_entire=True)
+        print source
+
+
+class CyPrint(CythonCommand):
+    """
+    Print a Cython variable using 'cy-print x' or 'cy-print module.function.x'
+    """
+    
+    name = 'cy print'
+    command_class = gdb.COMMAND_DATA
+    
+    def invoke(self, name, from_tty, max_name_length=None):
+        if self.is_python_function():
+            return gdb.execute('py-print ' + name)
+        elif self.is_cython_function():
+            value = self.cy.cy_cvalue.invoke(name.lstrip('*'))
+            for c in name:
+                if c == '*':
+                    value = value.dereference()
+                else:
+                    break
+                
+            self.print_gdb_value(name, value, max_name_length)
+        else:
+            gdb.execute('print ' + name)
+        
+    def complete(self):
+        if self.is_cython_function():
+            f = self.get_cython_function()
+            return list(itertools.chain(f.locals, f.globals))
+        else:
+            return []
+
+
+sortkey = lambda (name, value): name.lower()
+
+class CyLocals(CythonCommand):
+    """
+    List the locals from the current Cython frame.
+    """
+    
+    name = 'cy locals'
+    command_class = gdb.COMMAND_STACK
+    completer_class = gdb.COMPLETE_NONE
+    
+    @dispatch_on_frame(c_command='info locals', python_command='py-locals')
+    def invoke(self, args, from_tty):
+        local_cython_vars = self.get_cython_function().locals
+        max_name_length = len(max(local_cython_vars, key=len))
+        for name, cyvar in sorted(local_cython_vars.iteritems(), key=sortkey):
+            if self.is_initialized(self.get_cython_function(), cyvar.name):
+                value = gdb.parse_and_eval(cyvar.cname)
+                if not value.is_optimized_out:
+                    self.print_gdb_value(cyvar.name, value, 
+                                         max_name_length, '')
+
+
+class CyGlobals(CyLocals):
+    """
+    List the globals from the current Cython module.
+    """
+    
+    name = 'cy globals'
+    command_class = gdb.COMMAND_STACK
+    completer_class = gdb.COMPLETE_NONE
+    
+    @dispatch_on_frame(c_command='info variables', python_command='py-globals')
+    def invoke(self, args, from_tty):
+        global_python_dict = self.get_cython_globals_dict()
+        module_globals = self.get_cython_function().module.globals
+        
+        max_globals_len = 0
+        max_globals_dict_len = 0
+        if module_globals:
+            max_globals_len = len(max(module_globals, key=len))
+        if global_python_dict:
+            max_globals_dict_len = len(max(global_python_dict))
+            
+        max_name_length = max(max_globals_len, max_globals_dict_len)
+        
+        seen = set()
+        print 'Python globals:'
+        for k, v in sorted(global_python_dict.iteritems(), key=sortkey):
+            v = v.get_truncated_repr(libpython.MAX_OUTPUT_LEN)
+            seen.add(k)
+            print '    %-*s = %s' % (max_name_length, k, v)
+        
+        print 'C globals:'
+        for name, cyvar in sorted(module_globals.iteritems(), key=sortkey):
+            if name not in seen:
+                try:
+                    value = gdb.parse_and_eval(cyvar.cname)
+                except RuntimeError:
+                    pass
+                else:
+                    if not value.is_optimized_out:
+                        self.print_gdb_value(cyvar.name, value,
+                                             max_name_length, '    ')
+
+
+class CyExec(CythonCommand, libpython.PyExec):
+    """
+    Execute Python code in the nearest Python or Cython frame.
+    """
+    
+    name = '-cy-exec'
+    command_class = gdb.COMMAND_STACK
+    completer_class = gdb.COMPLETE_NONE
+    
+    def _fill_locals_dict(self, executor, local_dict_pointer):
+        "Fill a remotely allocated dict with values from the Cython C stack"
+        cython_func = self.get_cython_function()
+        current_lineno = self.get_cython_lineno()
+        
+        for name, cyvar in cython_func.locals.iteritems():
+            if (cyvar.type == PythonObject and 
+                self.is_initialized(cython_func, name)):
+                
+                try:
+                    val = gdb.parse_and_eval(cyvar.cname)
+                except RuntimeError:
+                    continue
+                else:
+                    if val.is_optimized_out:
+                        continue
+                
+                pystringp = executor.alloc_pystring(name)
+                code = '''
+                    (PyObject *) PyDict_SetItem(
+                        (PyObject *) %d,
+                        (PyObject *) %d,
+                        (PyObject *) %s)
+                ''' % (local_dict_pointer, pystringp, cyvar.cname)
+
+                try:
+                    if gdb.parse_and_eval(code) < 0:
+                        gdb.parse_and_eval('PyErr_Print()')
+                        raise gdb.GdbError("Unable to execute Python code.")
+                finally:
+                    # PyDict_SetItem doesn't steal our reference
+                    executor.decref(pystringp)
+    
+    def _find_first_cython_or_python_frame(self):
+        frame = gdb.selected_frame()
+        while frame:
+            if (self.is_cython_function(frame) or 
+                self.is_python_function(frame)):
+                return frame
+            
+            frame = frame.older()
+        
+        raise gdb.GdbError("There is no Cython or Python frame on the stack.")
+        
+    def invoke(self, expr, from_tty):
+        frame = self._find_first_cython_or_python_frame()
+        if self.is_python_function(frame):
+            libpython.py_exec.invoke(expr, from_tty)
+            return
+        
+        expr, input_type = self.readcode(expr)
+        executor = libpython.PythonCodeExecutor()
+        
+        with libpython.FetchAndRestoreError():
+            # get the dict of Cython globals and construct a dict in the 
+            # inferior with Cython locals
+            global_dict = gdb.parse_and_eval(
+                '(PyObject *) PyModule_GetDict(__pyx_m)')
+            local_dict = gdb.parse_and_eval('(PyObject *) PyDict_New()')
+            
+            cython_function = self.get_cython_function()
+            
+            try:
+                self._fill_locals_dict(executor, 
+                                       libpython.pointervalue(local_dict))
+                executor.evalcode(expr, input_type, global_dict, local_dict)
+            finally:
+                executor.decref(libpython.pointervalue(local_dict))
+
+
+# Functions
+
+class CyCName(gdb.Function, CythonBase):
+    """
+    Get the C name of a Cython variable in the current context.
+    Examples:
+        
+        print $cy_cname("function")
+        print $cy_cname("Class.method")
+        print $cy_cname("module.function")
+    """
+    
+    @require_cython_frame
+    @gdb_function_value_to_unicode
+    def invoke(self, cyname, frame=None):
+        frame = frame or gdb.selected_frame()
+        cname = None
+        
+        if self.is_cython_function(frame):
+            cython_function = self.get_cython_function(frame)
+            if cyname in cython_function.locals:
+                cname = cython_function.locals[cyname].cname
+            elif cyname in cython_function.module.globals:
+                cname = cython_function.module.globals[cyname].cname
+            else:
+                qname = '%s.%s' % (cython_function.module.name, cyname)
+                if qname in cython_function.module.functions:
+                    cname = cython_function.module.functions[qname].cname
+            
+        if not cname:
+            cname = self.cy.functions_by_qualified_name.get(cyname)
+            
+        if not cname:
+            raise gdb.GdbError('No such Cython variable: %s' % cyname)
+        
+        return cname
+
+
+class CyCValue(CyCName):
+    """
+    Get the value of a Cython variable.
+    """
+    
+    @require_cython_frame
+    @gdb_function_value_to_unicode
+    def invoke(self, cyname, frame=None):
+        try:
+            cname = super(CyCValue, self).invoke(cyname, frame=frame)
+            return gdb.parse_and_eval(cname)
+        except (gdb.GdbError, RuntimeError), e:
+            # variable exists but may not have been initialized yet, or may be
+            # in the globals dict of the Cython module
+            d = self.get_cython_globals_dict()
+            if cyname in d:
+                return d[cyname]._gdbval
+
+            raise gdb.GdbError(str(e))
+
+
+class CyLine(gdb.Function, CythonBase):
+    """
+    Get the current Cython line.
+    """
+    
+    @require_cython_frame
+    def invoke(self):
+        return self.get_cython_lineno()
+
+
+cy = CyCy.register()
\ No newline at end of file

Cython/Debugger/libpython.py

+#!/usr/bin/python
+
+# NOTE: this file is taken from the Python source distribution
+# It can be found under Tools/gdb/libpython.py. It is shipped with Cython
+# because it's not installed as a python module, and because changes are only
+# merged into new python versions (v3.2+).
+
+'''
+From gdb 7 onwards, gdb's build can be configured --with-python, allowing gdb
+to be extended with Python code e.g. for library-specific data visualizations,
+such as for the C++ STL types.  Documentation on this API can be seen at:
+http://sourceware.org/gdb/current/onlinedocs/gdb/Python-API.html
+
+
+This python module deals with the case when the process being debugged (the
+"inferior process" in gdb parlance) is itself python, or more specifically,
+linked against libpython.  In this situation, almost every item of data is a
+(PyObject*), and having the debugger merely print their addresses is not very
+enlightening.
+
+This module embeds knowledge about the implementation details of libpython so
+that we can emit useful visualizations e.g. a string, a list, a dict, a frame
+giving file/line information and the state of local variables
+
+In particular, given a gdb.Value corresponding to a PyObject* in the inferior
+process, we can generate a "proxy value" within the gdb process.  For example,
+given a PyObject* in the inferior process that is in fact a PyListObject*
+holding three PyObject* that turn out to be PyStringObject* instances, we can
+generate a proxy value within the gdb process that is a list of strings:
+  ["foo", "bar", "baz"]
+
+Doing so can be expensive for complicated graphs of objects, and could take
+some time, so we also have a "write_repr" method that writes a representation
+of the data to a file-like object.  This allows us to stop the traversal by
+having the file-like object raise an exception if it gets too much data.
+
+With both "proxyval" and "write_repr" we keep track of the set of all addresses
+visited so far in the traversal, to avoid infinite recursion due to cycles in
+the graph of object references.
+
+We try to defer gdb.lookup_type() invocations for python types until as late as
+possible: for a dynamically linked python binary, when the process starts in
+the debugger, the libpython.so hasn't been dynamically loaded yet, so none of
+the type names are known to the debugger
+
+The module also extends gdb with some python-specific commands.
+'''
+from __future__ import with_statement
+
+import os
+import re
+import sys
+import struct
+import locale
+import atexit
+import warnings
+import tempfile
+import itertools
+
+import gdb
+
+if sys.version_info[0] < 3:
+    # I think this is the only way to fix this bug :'(
+    # http://sourceware.org/bugzilla/show_bug.cgi?id=12285
+    out, err = sys.stdout, sys.stderr
+    reload(sys).setdefaultencoding('UTF-8')
+    sys.stdout = out
+    sys.stderr = err
+
+# Look up the gdb.Type for some standard types:
+_type_char_ptr = gdb.lookup_type('char').pointer() # char*
+_type_unsigned_char_ptr = gdb.lookup_type('unsigned char').pointer() # unsigned char*
+_type_void_ptr = gdb.lookup_type('void').pointer() # void*
+
+SIZEOF_VOID_P = _type_void_ptr.sizeof
+
+
+Py_TPFLAGS_HEAPTYPE = (1L << 9)
+
+Py_TPFLAGS_INT_SUBCLASS      = (1L << 23)
+Py_TPFLAGS_LONG_SUBCLASS     = (1L << 24)
+Py_TPFLAGS_LIST_SUBCLASS     = (1L << 25)
+Py_TPFLAGS_TUPLE_SUBCLASS    = (1L << 26)
+Py_TPFLAGS_STRING_SUBCLASS   = (1L << 27)
+Py_TPFLAGS_BYTES_SUBCLASS    = (1L << 27)
+Py_TPFLAGS_UNICODE_SUBCLASS  = (1L << 28)
+Py_TPFLAGS_DICT_SUBCLASS     = (1L << 29)
+Py_TPFLAGS_BASE_EXC_SUBCLASS = (1L << 30)
+Py_TPFLAGS_TYPE_SUBCLASS     = (1L << 31)
+
+
+MAX_OUTPUT_LEN=1024
+
+hexdigits = "0123456789abcdef"
+
+ENCODING = locale.getpreferredencoding()
+
+class NullPyObjectPtr(RuntimeError):
+    pass
+
+
+def safety_limit(val):
+    # Given a integer value from the process being debugged, limit it to some
+    # safety threshold so that arbitrary breakage within said process doesn't
+    # break the gdb process too much (e.g. sizes of iterations, sizes of lists)
+    return min(val, 1000)
+
+
+def safe_range(val):
+    # As per range, but don't trust the value too much: cap it to a safety
+    # threshold in case the data was corrupted
+    return xrange(safety_limit(val))
+
+def write_unicode(file, text):
+    # Write a byte or unicode string to file. Unicode strings are encoded to
+    # ENCODING encoding with 'backslashreplace' error handler to avoid
+    # UnicodeEncodeError.
+    if isinstance(text, unicode):
+        text = text.encode(ENCODING, 'backslashreplace')
+    file.write(text)
+
+def os_fsencode(filename):
+    if not isinstance(filename, unicode):
+        return filename
+    encoding = sys.getfilesystemencoding()
+    if encoding == 'mbcs':
+        # mbcs doesn't support surrogateescape
+        return filename.encode(encoding)
+    encoded = []
+    for char in filename:
+        # surrogateescape error handler
+        if 0xDC80 <= ord(char) <= 0xDCFF:
+            byte = chr(ord(char) - 0xDC00)
+        else:
+            byte = char.encode(encoding)
+        encoded.append(byte)
+    return ''.join(encoded)
+
+class StringTruncated(RuntimeError):
+    pass
+
+class TruncatedStringIO(object):
+    '''Similar to cStringIO, but can truncate the output by raising a
+    StringTruncated exception'''
+    def __init__(self, maxlen=None):
+        self._val = ''
+        self.maxlen = maxlen
+
+    def write(self, data):
+        if self.maxlen:
+            if len(data) + len(self._val) > self.maxlen:
+                # Truncation:
+                self._val += data[0:self.maxlen - len(self._val)]
+                raise StringTruncated()
+
+        self._val += data
+
+    def getvalue(self):
+        return self._val
+
+class PyObjectPtr(object):
+    """
+    Class wrapping a gdb.Value that's a either a (PyObject*) within the
+    inferior process, or some subclass pointer e.g. (PyStringObject*)
+
+    There will be a subclass for every refined PyObject type that we care
+    about.
+
+    Note that at every stage the underlying pointer could be NULL, point
+    to corrupt data, etc; this is the debugger, after all.
+    """
+    _typename = 'PyObject'
+
+    def __init__(self, gdbval, cast_to=None):
+        if cast_to:
+            self._gdbval = gdbval.cast(cast_to)
+        else:
+            self._gdbval = gdbval
+
+    def field(self, name):
+        '''
+        Get the gdb.Value for the given field within the PyObject, coping with
+        some python 2 versus python 3 differences.
+
+        Various libpython types are defined using the "PyObject_HEAD" and
+        "PyObject_VAR_HEAD" macros.
+
+        In Python 2, this these are defined so that "ob_type" and (for a var
+        object) "ob_size" are fields of the type in question.
+
+        In Python 3, this is defined as an embedded PyVarObject type thus:
+           PyVarObject ob_base;
+        so that the "ob_size" field is located insize the "ob_base" field, and
+        the "ob_type" is most easily accessed by casting back to a (PyObject*).
+        '''
+        if self.is_null():
+            raise NullPyObjectPtr(self)
+
+        if name == 'ob_type':
+            pyo_ptr = self._gdbval.cast(PyObjectPtr.get_gdb_type())
+            return pyo_ptr.dereference()[name]
+
+        if name == 'ob_size':
+            pyo_ptr = self._gdbval.cast(PyVarObjectPtr.get_gdb_type())
+            return pyo_ptr.dereference()[name]
+
+        # General case: look it up inside the object:
+        return self._gdbval.dereference()[name]
+
+    def pyop_field(self, name):
+        '''
+        Get a PyObjectPtr for the given PyObject* field within this PyObject,
+        coping with some python 2 versus python 3 differences.
+        '''
+        return PyObjectPtr.from_pyobject_ptr(self.field(name))
+
+    def write_field_repr(self, name, out, visited):
+        '''
+        Extract the PyObject* field named "name", and write its representation
+        to file-like object "out"
+        '''
+        field_obj = self.pyop_field(name)
+        field_obj.write_repr(out, visited)
+
+    def get_truncated_repr(self, maxlen):
+        '''
+        Get a repr-like string for the data, but truncate it at "maxlen" bytes
+        (ending the object graph traversal as soon as you do)
+        '''
+        out = TruncatedStringIO(maxlen)
+        try:
+            self.write_repr(out, set())
+        except StringTruncated:
+            # Truncation occurred:
+            return out.getvalue() + '...(truncated)'
+
+        # No truncation occurred:
+        return out.getvalue()
+
+    def type(self):
+        return PyTypeObjectPtr(self.field('ob_type'))
+
+    def is_null(self):
+        return 0 == long(self._gdbval)
+
+    def is_optimized_out(self):
+        '''
+        Is the value of the underlying PyObject* visible to the debugger?
+
+        This can vary with the precise version of the compiler used to build
+        Python, and the precise version of gdb.
+
+        See e.g. https://bugzilla.redhat.com/show_bug.cgi?id=556975 with
+        PyEval_EvalFrameEx's "f"
+        '''
+        return self._gdbval.is_optimized_out
+
+    def safe_tp_name(self):
+        try:
+            return self.type().field('tp_name').string()
+        except NullPyObjectPtr:
+            # NULL tp_name?
+            return 'unknown'
+        except RuntimeError:
+            # Can't even read the object at all?
+            return 'unknown'
+
+    def proxyval(self, visited):
+        '''
+        Scrape a value from the inferior process, and try to represent it
+        within the gdb process, whilst (hopefully) avoiding crashes when
+        the remote data is corrupt.
+
+        Derived classes will override this.
+
+        For example, a PyIntObject* with ob_ival 42 in the inferior process
+        should result in an int(42) in this process.
+
+        visited: a set of all gdb.Value pyobject pointers already visited
+        whilst generating this value (to guard against infinite recursion when
+        visiting object graphs with loops).  Analogous to Py_ReprEnter and
+        Py_ReprLeave
+        '''
+
+        class FakeRepr(object):
+            """
+            Class representing a non-descript PyObject* value in the inferior
+            process for when we don't have a custom scraper, intended to have
+            a sane repr().
+            """
+
+            def __init__(self, tp_name, address):
+                self.tp_name = tp_name
+                self.address = address
+
+            def __repr__(self):
+                # For the NULL pointer, we have no way of knowing a type, so
+                # special-case it as per
+                # http://bugs.python.org/issue8032#msg100882
+                if self.address == 0:
+                    return '0x0'
+                return '<%s at remote 0x%x>' % (self.tp_name, self.address)
+
+        return FakeRepr(self.safe_tp_name(),
+                        long(self._gdbval))
+
+    def write_repr(self, out, visited):
+        '''
+        Write a string representation of the value scraped from the inferior
+        process to "out", a file-like object.
+        '''
+        # Default implementation: generate a proxy value and write its repr
+        # However, this could involve a lot of work for complicated objects,
+        # so for derived classes we specialize this
+        return out.write(repr(self.proxyval(visited)))
+
+    @classmethod
+    def subclass_from_type(cls, t):
+        '''
+        Given a PyTypeObjectPtr instance wrapping a gdb.Value that's a
+        (PyTypeObject*), determine the corresponding subclass of PyObjectPtr
+        to use
+
+        Ideally, we would look up the symbols for the global types, but that
+        isn't working yet:
+          (gdb) python print gdb.lookup_symbol('PyList_Type')[0].value
+          Traceback (most recent call last):
+            File "<string>", line 1, in <module>
+          NotImplementedError: Symbol type not yet supported in Python scripts.
+          Error while executing Python code.
+
+        For now, we use tp_flags, after doing some string comparisons on the
+        tp_name for some special-cases that don't seem to be visible through
+        flags
+        '''
+        try:
+            tp_name = t.field('tp_name').string()
+            tp_flags = int(t.field('tp_flags'))
+        except RuntimeError:
+            # Handle any kind of error e.g. NULL ptrs by simply using the base
+            # class
+            return cls
+
+        #print 'tp_flags = 0x%08x' % tp_flags
+        #print 'tp_name = %r' % tp_name
+        
+        name_map = {'bool': PyBoolObjectPtr,
+                    'classobj': PyClassObjectPtr,
+                    'instance': PyInstanceObjectPtr,
+                    'NoneType': PyNoneStructPtr,
+                    'frame': PyFrameObjectPtr,
+                    'set' : PySetObjectPtr,
+                    'frozenset' : PySetObjectPtr,
+                    'builtin_function_or_method' : PyCFunctionObjectPtr,
+                    }
+        if tp_name in name_map:
+            return name_map[tp_name]
+
+        if tp_flags & Py_TPFLAGS_HEAPTYPE:
+            return HeapTypeObjectPtr
+
+        if tp_flags & Py_TPFLAGS_INT_SUBCLASS:
+            return PyIntObjectPtr
+        if tp_flags & Py_TPFLAGS_LONG_SUBCLASS:
+            return PyLongObjectPtr
+        if tp_flags & Py_TPFLAGS_LIST_SUBCLASS:
+            return PyListObjectPtr
+        if tp_flags & Py_TPFLAGS_TUPLE_SUBCLASS:
+            return PyTupleObjectPtr
+        if tp_flags & Py_TPFLAGS_STRING_SUBCLASS:
+            try:
+                gdb.lookup_type('PyBytesObject')
+                return PyBytesObjectPtr
+            except RuntimeError:
+                return PyStringObjectPtr
+        if tp_flags & Py_TPFLAGS_UNICODE_SUBCLASS:
+            return PyUnicodeObjectPtr
+        if tp_flags & Py_TPFLAGS_DICT_SUBCLASS:
+            return PyDictObjectPtr
+        if tp_flags & Py_TPFLAGS_BASE_EXC_SUBCLASS:
+            return PyBaseExceptionObjectPtr
+        #if tp_flags & Py_TPFLAGS_TYPE_SUBCLASS:
+        #    return PyTypeObjectPtr
+
+        # Use the base class:
+        return cls
+
+    @classmethod
+    def from_pyobject_ptr(cls, gdbval):
+        '''
+        Try to locate the appropriate derived class dynamically, and cast
+        the pointer accordingly.
+        '''
+        try:
+            p = PyObjectPtr(gdbval)
+            cls = cls.subclass_from_type(p.type())
+            return cls(gdbval, cast_to=cls.get_gdb_type())
+        except RuntimeError, exc:
+            # Handle any kind of error e.g. NULL ptrs by simply using the base
+            # class
+            pass
+        return cls(gdbval)
+
+    @classmethod
+    def get_gdb_type(cls):
+        return gdb.lookup_type(cls._typename).pointer()
+
+    def as_address(self):
+        return long(self._gdbval)
+
+class PyVarObjectPtr(PyObjectPtr):
+    _typename = 'PyVarObject'
+
+class ProxyAlreadyVisited(object):
+    '''
+    Placeholder proxy to use when protecting against infinite recursion due to
+    loops in the object graph.
+
+    Analogous to the values emitted by the users of Py_ReprEnter and Py_ReprLeave
+    '''
+    def __init__(self, rep):
+        self._rep = rep
+
+    def __repr__(self):
+        return self._rep
+
+
+def _write_instance_repr(out, visited, name, pyop_attrdict, address):
+    '''Shared code for use by old-style and new-style classes:
+    write a representation to file-like object "out"'''
+    out.write('<')
+    out.write(name)
+
+    # Write dictionary of instance attributes:
+    if isinstance(pyop_attrdict, PyDictObjectPtr):
+        out.write('(')
+        first = True
+        for pyop_arg, pyop_val in pyop_attrdict.iteritems():
+            if not first:
+                out.write(', ')
+            first = False
+            out.write(pyop_arg.proxyval(visited))
+            out.write('=')
+            pyop_val.write_repr(out, visited)
+        out.write(')')
+    out.write(' at remote 0x%x>' % address)
+
+
+class InstanceProxy(object):
+
+    def __init__(self, cl_name, attrdict, address):
+        self.cl_name = cl_name
+        self.attrdict = attrdict
+        self.address = address
+
+    def __repr__(self):
+        if isinstance(self.attrdict, dict):
+            kwargs = ', '.join(["%s=%r" % (arg, val)
+                                for arg, val in self.attrdict.iteritems()])
+            return '<%s(%s) at remote 0x%x>' % (self.cl_name,
+                                                kwargs, self.address)
+        else:
+            return '<%s at remote 0x%x>' % (self.cl_name,
+                                            self.address)
+
+def _PyObject_VAR_SIZE(typeobj, nitems):
+    return ( ( typeobj.field('tp_basicsize') +
+               nitems * typeobj.field('tp_itemsize') +
+               (SIZEOF_VOID_P - 1)
+             ) & ~(SIZEOF_VOID_P - 1)
+           ).cast(gdb.lookup_type('size_t'))
+
+class HeapTypeObjectPtr(PyObjectPtr):
+    _typename = 'PyObject'
+
+    def get_attr_dict(self):
+        '''
+        Get the PyDictObject ptr representing the attribute dictionary
+        (or None if there's a problem)
+        '''
+        try:
+            typeobj = self.type()
+            dictoffset = int_from_int(typeobj.field('tp_dictoffset'))
+            if dictoffset != 0:
+                if dictoffset < 0:
+                    type_PyVarObject_ptr = gdb.lookup_type('PyVarObject').pointer()
+                    tsize = int_from_int(self._gdbval.cast(type_PyVarObject_ptr)['ob_size'])
+                    if tsize < 0:
+                        tsize = -tsize
+                    size = _PyObject_VAR_SIZE(typeobj, tsize)
+                    dictoffset += size
+                    assert dictoffset > 0
+                    assert dictoffset % SIZEOF_VOID_P == 0
+
+                dictptr = self._gdbval.cast(_type_char_ptr) + dictoffset
+                PyObjectPtrPtr = PyObjectPtr.get_gdb_type().pointer()
+                dictptr = dictptr.cast(PyObjectPtrPtr)
+                return PyObjectPtr.from_pyobject_ptr(dictptr.dereference())
+        except RuntimeError:
+            # Corrupt data somewhere; fail safe
+            pass
+
+        # Not found, or some kind of error:
+        return None
+
+    def proxyval(self, visited):
+        '''
+        Support for new-style classes.
+
+        Currently we just locate the dictionary using a transliteration to
+        python of _PyObject_GetDictPtr, ignoring descriptors
+        '''
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('<...>')
+        visited.add(self.as_address())
+
+        pyop_attr_dict = self.get_attr_dict()
+        if pyop_attr_dict:
+            attr_dict = pyop_attr_dict.proxyval(visited)
+        else:
+            attr_dict = {}
+        tp_name = self.safe_tp_name()
+
+        # New-style class:
+        return InstanceProxy(tp_name, attr_dict, long(self._gdbval))
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('<...>')
+            return
+        visited.add(self.as_address())
+
+        pyop_attrdict = self.get_attr_dict()
+        _write_instance_repr(out, visited,
+                             self.safe_tp_name(), pyop_attrdict, self.as_address())
+
+class ProxyException(Exception):
+    def __init__(self, tp_name, args):
+        self.tp_name = tp_name
+        self.args = args
+
+    def __repr__(self):
+        return '%s%r' % (self.tp_name, self.args)
+
+class PyBaseExceptionObjectPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyBaseExceptionObject* i.e. an exception
+    within the process being debugged.
+    """
+    _typename = 'PyBaseExceptionObject'
+
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('(...)')
+        visited.add(self.as_address())
+        arg_proxy = self.pyop_field('args').proxyval(visited)
+        return ProxyException(self.safe_tp_name(),
+                              arg_proxy)
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('(...)')
+            return
+        visited.add(self.as_address())
+
+        out.write(self.safe_tp_name())
+        self.write_field_repr('args', out, visited)
+
+
+class PyClassObjectPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyClassObject* i.e. a <classobj>
+    instance within the process being debugged.
+    """
+    _typename = 'PyClassObject'
+
+
+class BuiltInFunctionProxy(object):
+    def __init__(self, ml_name):
+        self.ml_name = ml_name
+
+    def __repr__(self):
+        return "<built-in function %s>" % self.ml_name
+
+class BuiltInMethodProxy(object):
+    def __init__(self, ml_name, pyop_m_self):
+        self.ml_name = ml_name
+        self.pyop_m_self = pyop_m_self
+
+    def __repr__(self):
+        return ('<built-in method %s of %s object at remote 0x%x>'
+                % (self.ml_name,
+                   self.pyop_m_self.safe_tp_name(),
+                   self.pyop_m_self.as_address())
+                )
+
+class PyCFunctionObjectPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyCFunctionObject*
+    (see Include/methodobject.h and Objects/methodobject.c)
+    """
+    _typename = 'PyCFunctionObject'
+
+    def proxyval(self, visited):
+        m_ml = self.field('m_ml') # m_ml is a (PyMethodDef*)
+        ml_name = m_ml['ml_name'].string()
+
+        pyop_m_self = self.pyop_field('m_self')
+        if pyop_m_self.is_null():
+            return BuiltInFunctionProxy(ml_name)
+        else:
+            return BuiltInMethodProxy(ml_name, pyop_m_self)
+
+
+class PyCodeObjectPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyCodeObject* i.e. a <code> instance
+    within the process being debugged.
+    """
+    _typename = 'PyCodeObject'
+
+    def addr2line(self, addrq):
+        '''
+        Get the line number for a given bytecode offset
+
+        Analogous to PyCode_Addr2Line; translated from pseudocode in
+        Objects/lnotab_notes.txt
+        '''
+        co_lnotab = self.pyop_field('co_lnotab').proxyval(set())
+
+        # Initialize lineno to co_firstlineno as per PyCode_Addr2Line
+        # not 0, as lnotab_notes.txt has it:
+        lineno = int_from_int(self.field('co_firstlineno'))
+
+        addr = 0
+        for addr_incr, line_incr in zip(co_lnotab[::2], co_lnotab[1::2]):
+            addr += ord(addr_incr)
+            if addr > addrq:
+                return lineno
+            lineno += ord(line_incr)
+        return lineno
+
+
+class PyDictObjectPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyDictObject* i.e. a dict instance
+    within the process being debugged.
+    """
+    _typename = 'PyDictObject'
+
+    def iteritems(self):
+        '''
+        Yields a sequence of (PyObjectPtr key, PyObjectPtr value) pairs,
+        analagous to dict.iteritems()
+        '''
+        for i in safe_range(self.field('ma_mask') + 1):
+            ep = self.field('ma_table') + i
+            pyop_value = PyObjectPtr.from_pyobject_ptr(ep['me_value'])
+            if not pyop_value.is_null():
+                pyop_key = PyObjectPtr.from_pyobject_ptr(ep['me_key'])
+                yield (pyop_key, pyop_value)
+    
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('{...}')
+        visited.add(self.as_address())
+
+        result = {}
+        for pyop_key, pyop_value in self.iteritems():
+            proxy_key = pyop_key.proxyval(visited)
+            proxy_value = pyop_value.proxyval(visited)
+            result[proxy_key] = proxy_value
+        return result
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('{...}')
+            return
+        visited.add(self.as_address())
+
+        out.write('{')
+        first = True
+        for pyop_key, pyop_value in self.iteritems():
+            if not first:
+                out.write(', ')
+            first = False
+            pyop_key.write_repr(out, visited)
+            out.write(': ')
+            pyop_value.write_repr(out, visited)
+        out.write('}')
+
+class PyInstanceObjectPtr(PyObjectPtr):
+    _typename = 'PyInstanceObject'
+
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('<...>')
+        visited.add(self.as_address())
+
+        # Get name of class:
+        in_class = self.pyop_field('in_class')
+        cl_name = in_class.pyop_field('cl_name').proxyval(visited)
+
+        # Get dictionary of instance attributes:
+        in_dict = self.pyop_field('in_dict').proxyval(visited)
+
+        # Old-style class:
+        return InstanceProxy(cl_name, in_dict, long(self._gdbval))
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('<...>')
+            return
+        visited.add(self.as_address())
+
+        # Old-style class:
+
+        # Get name of class:
+        in_class = self.pyop_field('in_class')
+        cl_name = in_class.pyop_field('cl_name').proxyval(visited)
+
+        # Get dictionary of instance attributes:
+        pyop_in_dict = self.pyop_field('in_dict')
+
+        _write_instance_repr(out, visited,
+                             cl_name, pyop_in_dict, self.as_address())
+
+class PyIntObjectPtr(PyObjectPtr):
+    _typename = 'PyIntObject'
+
+    def proxyval(self, visited):
+        result = int_from_int(self.field('ob_ival'))
+        return result
+
+class PyListObjectPtr(PyObjectPtr):
+    _typename = 'PyListObject'
+
+    def __getitem__(self, i):
+        # Get the gdb.Value for the (PyObject*) with the given index:
+        field_ob_item = self.field('ob_item')
+        return field_ob_item[i]
+
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('[...]')
+        visited.add(self.as_address())
+
+        result = [PyObjectPtr.from_pyobject_ptr(self[i]).proxyval(visited)
+                  for i in safe_range(int_from_int(self.field('ob_size')))]
+        return result
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('[...]')
+            return
+        visited.add(self.as_address())
+
+        out.write('[')
+        for i in safe_range(int_from_int(self.field('ob_size'))):
+            if i > 0:
+                out.write(', ')
+            element = PyObjectPtr.from_pyobject_ptr(self[i])
+            element.write_repr(out, visited)
+        out.write(']')
+
+class PyLongObjectPtr(PyObjectPtr):
+    _typename = 'PyLongObject'
+
+    def proxyval(self, visited):
+        '''
+        Python's Include/longobjrep.h has this declaration:
+           struct _longobject {
+               PyObject_VAR_HEAD
+               digit ob_digit[1];
+           };
+
+        with this description:
+            The absolute value of a number is equal to
+                 SUM(for i=0 through abs(ob_size)-1) ob_digit[i] * 2**(SHIFT*i)
+            Negative numbers are represented with ob_size < 0;
+            zero is represented by ob_size == 0.
+
+        where SHIFT can be either:
+            #define PyLong_SHIFT        30
+            #define PyLong_SHIFT        15
+        '''
+        ob_size = long(self.field('ob_size'))
+        if ob_size == 0:
+            return 0L
+
+        ob_digit = self.field('ob_digit')
+
+        if gdb.lookup_type('digit').sizeof == 2:
+            SHIFT = 15L
+        else:
+            SHIFT = 30L
+
+        digits = [long(ob_digit[i]) * 2**(SHIFT*i)
+                  for i in safe_range(abs(ob_size))]
+        result = sum(digits)
+        if ob_size < 0:
+            result = -result
+        return result
+
+    def write_repr(self, out, visited):
+        # Write this out as a Python 3 int literal, i.e. without the "L" suffix
+        proxy = self.proxyval(visited)
+        out.write("%s" % proxy)
+
+
+class PyBoolObjectPtr(PyLongObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyBoolObject* i.e. one of the two
+    <bool> instances (Py_True/Py_False) within the process being debugged.
+    """
+    
+    def proxyval(self, visited):
+        return bool(PyLongObjectPtr.proxyval(self, visited))
+
+
+class PyNoneStructPtr(PyObjectPtr):
+    """
+    Class wrapping a gdb.Value that's a PyObject* pointing to the
+    singleton (we hope) _Py_NoneStruct with ob_type PyNone_Type
+    """
+    _typename = 'PyObject'
+
+    def proxyval(self, visited):
+        return None
+
+
+class PyFrameObjectPtr(PyObjectPtr):
+    _typename = 'PyFrameObject'
+
+    def __init__(self, gdbval, cast_to=None):
+        PyObjectPtr.__init__(self, gdbval, cast_to)
+
+        if not self.is_optimized_out():
+            self.co = PyCodeObjectPtr.from_pyobject_ptr(self.field('f_code'))
+            self.co_name = self.co.pyop_field('co_name')
+            self.co_filename = self.co.pyop_field('co_filename')
+
+            self.f_lineno = int_from_int(self.field('f_lineno'))
+            self.f_lasti = int_from_int(self.field('f_lasti'))
+            self.co_nlocals = int_from_int(self.co.field('co_nlocals'))
+            self.co_varnames = PyTupleObjectPtr.from_pyobject_ptr(self.co.field('co_varnames'))
+
+    def iter_locals(self):
+        '''
+        Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
+        the local variables of this frame
+        '''
+        if self.is_optimized_out():
+            return
+
+        f_localsplus = self.field('f_localsplus')
+        for i in safe_range(self.co_nlocals):
+            pyop_value = PyObjectPtr.from_pyobject_ptr(f_localsplus[i])
+            if not pyop_value.is_null():
+                pyop_name = PyObjectPtr.from_pyobject_ptr(self.co_varnames[i])
+                yield (pyop_name, pyop_value)
+
+    def iter_globals(self):
+        '''
+        Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
+        the global variables of this frame
+        '''
+        if self.is_optimized_out():
+            return
+
+        pyop_globals = self.pyop_field('f_globals')
+        return pyop_globals.iteritems()
+
+    def iter_builtins(self):
+        '''
+        Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
+        the builtin variables
+        '''
+        if self.is_optimized_out():
+            return
+
+        pyop_builtins = self.pyop_field('f_builtins')
+        return pyop_builtins.iteritems()
+
+    def get_var_by_name(self, name):
+        '''
+        Look for the named local variable, returning a (PyObjectPtr, scope) pair
+        where scope is a string 'local', 'global', 'builtin'
+
+        If not found, return (None, None)
+        '''
+        for pyop_name, pyop_value in self.iter_locals():
+            if name == pyop_name.proxyval(set()):
+                return pyop_value, 'local'
+        for pyop_name, pyop_value in self.iter_globals():
+            if name == pyop_name.proxyval(set()):
+                return pyop_value, 'global'
+        for pyop_name, pyop_value in self.iter_builtins():
+            if name == pyop_name.proxyval(set()):
+                return pyop_value, 'builtin'
+        return None, None
+
+    def filename(self):
+        '''Get the path of the current Python source file, as a string'''
+        if self.is_optimized_out():
+            return '(frame information optimized out)'
+        return self.co_filename.proxyval(set())
+
+    def current_line_num(self):
+        '''Get current line number as an integer (1-based)
+
+        Translated from PyFrame_GetLineNumber and PyCode_Addr2Line
+
+        See Objects/lnotab_notes.txt
+        '''
+        if self.is_optimized_out():
+            return None
+        f_trace = self.field('f_trace')
+        if long(f_trace) != 0:
+            # we have a non-NULL f_trace:
+            return self.f_lineno
+        else:
+            #try:
+            return self.co.addr2line(self.f_lasti)
+            #except ValueError:
+            #    return self.f_lineno
+
+    def current_line(self):
+        '''Get the text of the current source line as a string, with a trailing
+        newline character'''
+        if self.is_optimized_out():
+            return '(frame information optimized out)'
+        filename = self.filename()
+        with open(os_fsencode(filename), 'r') as f:
+            all_lines = f.readlines()
+            # Convert from 1-based current_line_num to 0-based list offset:
+            return all_lines[self.current_line_num()-1]
+
+    def write_repr(self, out, visited):
+        if self.is_optimized_out():
+            out.write('(frame information optimized out)')
+            return
+        out.write('Frame 0x%x, for file %s, line %i, in %s ('
+                  % (self.as_address(),
+                     self.co_filename.proxyval(visited),
+                     self.current_line_num(),
+                     self.co_name.proxyval(visited)))
+        first = True
+        for pyop_name, pyop_value in self.iter_locals():
+            if not first:
+                out.write(', ')
+            first = False
+
+            out.write(pyop_name.proxyval(visited))
+            out.write('=')
+            pyop_value.write_repr(out, visited)
+
+        out.write(')')
+
+class PySetObjectPtr(PyObjectPtr):
+    _typename = 'PySetObject'
+
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('%s(...)' % self.safe_tp_name())
+        visited.add(self.as_address())
+
+        members = []
+        table = self.field('table')
+        for i in safe_range(self.field('mask')+1):
+            setentry = table[i]
+            key = setentry['key']
+            if key != 0:
+                key_proxy = PyObjectPtr.from_pyobject_ptr(key).proxyval(visited)
+                if key_proxy != '<dummy key>':
+                    members.append(key_proxy)
+        if self.safe_tp_name() == 'frozenset':
+            return frozenset(members)
+        else:
+            return set(members)
+
+    def write_repr(self, out, visited):
+        # Emulate Python 3's set_repr
+        tp_name = self.safe_tp_name()
+
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('(...)')
+            return
+        visited.add(self.as_address())
+
+        # Python 3's set_repr special-cases the empty set:
+        if not self.field('used'):
+            out.write(tp_name)
+            out.write('()')
+            return
+
+        # Python 3 uses {} for set literals:
+        if tp_name != 'set':
+            out.write(tp_name)
+            out.write('(')
+
+        out.write('{')
+        first = True
+        table = self.field('table')
+        for i in safe_range(self.field('mask')+1):
+            setentry = table[i]
+            key = setentry['key']
+            if key != 0:
+                pyop_key = PyObjectPtr.from_pyobject_ptr(key)
+                key_proxy = pyop_key.proxyval(visited) # FIXME!
+                if key_proxy != '<dummy key>':
+                    if not first:
+                        out.write(', ')
+                    first = False
+                    pyop_key.write_repr(out, visited)
+        out.write('}')
+
+        if tp_name != 'set':
+            out.write(')')
+
+
+class PyBytesObjectPtr(PyObjectPtr):
+    _typename = 'PyBytesObject'
+
+    def __str__(self):
+        field_ob_size = self.field('ob_size')
+        field_ob_sval = self.field('ob_sval')
+        return ''.join(struct.pack('b', field_ob_sval[i]) 
+                           for i in safe_range(field_ob_size))
+
+    def proxyval(self, visited):
+        return str(self)
+
+    def write_repr(self, out, visited):
+        # Write this out as a Python 3 bytes literal, i.e. with a "b" prefix
+
+        # Get a PyStringObject* within the Python 2 gdb process:
+        proxy = self.proxyval(visited)
+
+        # Transliteration of Python 3's Objects/bytesobject.c:PyBytes_Repr
+        # to Python 2 code:
+        quote = "'"
+        if "'" in proxy and not '"' in proxy:
+            quote = '"'
+        out.write('b')
+        out.write(quote)
+        for byte in proxy:
+            if byte == quote or byte == '\\':
+                out.write('\\')
+                out.write(byte)
+            elif byte == '\t':
+                out.write('\\t')
+            elif byte == '\n':
+                out.write('\\n')
+            elif byte == '\r':
+                out.write('\\r')
+            elif byte < ' ' or ord(byte) >= 0x7f:
+                out.write('\\x')
+                out.write(hexdigits[(ord(byte) & 0xf0) >> 4])
+                out.write(hexdigits[ord(byte) & 0xf])
+            else:
+                out.write(byte)
+        out.write(quote)
+
+class PyStringObjectPtr(PyBytesObjectPtr):
+    _typename = 'PyStringObject'
+
+
+class PyTupleObjectPtr(PyObjectPtr):
+    _typename = 'PyTupleObject'
+
+    def __getitem__(self, i):
+        # Get the gdb.Value for the (PyObject*) with the given index:
+        field_ob_item = self.field('ob_item')
+        return field_ob_item[i]
+
+    def proxyval(self, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            return ProxyAlreadyVisited('(...)')
+        visited.add(self.as_address())
+
+        result = tuple([PyObjectPtr.from_pyobject_ptr(self[i]).proxyval(visited)
+                        for i in safe_range(int_from_int(self.field('ob_size')))])
+        return result
+
+    def write_repr(self, out, visited):
+        # Guard against infinite loops:
+        if self.as_address() in visited:
+            out.write('(...)')
+            return
+        visited.add(self.as_address())
+
+        out.write('(')
+        for i in safe_range(int_from_int(self.field('ob_size'))):
+            if i > 0:
+                out.write(', ')
+            element = PyObjectPtr.from_pyobject_ptr(self[i])
+            element.write_repr(out, visited)
+        if self.field('ob_size') == 1:
+            out.write(',)')
+        else:
+            out.write(')')
+
+class PyTypeObjectPtr(PyObjectPtr):
+    _typename = 'PyTypeObject'
+
+
+def _unichr_is_printable(char):
+    # Logic adapted from Python 3's Tools/unicode/makeunicodedata.py
+    if char == u" ":
+        return True
+    import unicodedata
+    return unicodedata.category(char) not in ("C", "Z")
+
+if sys.maxunicode >= 0x10000:
+    _unichr = unichr
+else:
+    # Needed for proper surrogate support if sizeof(Py_UNICODE) is 2 in gdb
+    def _unichr(x):
+        if x < 0x10000:
+            return unichr(x)
+        x -= 0x10000
+        ch1 = 0xD800 | (x >> 10)
+        ch2 = 0xDC00 | (x & 0x3FF)
+        return unichr(ch1) + unichr(ch2)
+
+class PyUnicodeObjectPtr(PyObjectPtr):
+    _typename = 'PyUnicodeObject'
+
+    def char_width(self):
+        _type_Py_UNICODE = gdb.lookup_type('Py_UNICODE')
+        return _type_Py_UNICODE.sizeof
+
+    def proxyval(self, visited):
+        # From unicodeobject.h:
+        #     Py_ssize_t length;  /* Length of raw Unicode data in buffer */
+        #     Py_UNICODE *str;    /* Raw Unicode buffer */
+        field_length = long(self.field('length'))
+        field_str = self.field('str')
+
+        # Gather a list of ints from the Py_UNICODE array; these are either
+        # UCS-2 or UCS-4 code points:
+        if self.char_width() > 2:
+            Py_UNICODEs = [int(field_str[i]) for i in safe_range(field_length)]
+        else:
+            # A more elaborate routine if sizeof(Py_UNICODE) is 2 in the
+            # inferior process: we must join surrogate pairs.
+            Py_UNICODEs = []
+            i = 0
+            limit = safety_limit(field_length)
+            while i < limit:
+                ucs = int(field_str[i])
+                i += 1
+                if ucs < 0xD800 or ucs >= 0xDC00 or i == field_length:
+                    Py_UNICODEs.append(ucs)
+                    continue
+                # This could be a surrogate pair.
+                ucs2 = int(field_str[i])
+                if ucs2 < 0xDC00 or ucs2 > 0xDFFF:
+                    continue
+                code = (ucs & 0x03FF) << 10
+                code |= ucs2 & 0x03FF
+                code += 0x00010000
+                Py_UNICODEs.append(code)
+                i += 1
+
+        # Convert the int code points to unicode characters, and generate a
+        # local unicode instance.
+        # This splits surrogate pairs if sizeof(Py_UNICODE) is 2 here (in gdb).
+        result = u''.join([_unichr(ucs) for ucs in Py_UNICODEs])
+        return result
+
+    def write_repr(self, out, visited):
+        # Write this out as a Python 3 str literal, i.e. without a "u" prefix
+
+        # Get a PyUnicodeObject* within the Python 2 gdb process:
+        proxy = self.proxyval(visited)
+
+        # Transliteration of Python 3's Object/unicodeobject.c:unicode_repr
+        # to Python 2:
+        if "'" in proxy and '"' not in proxy:
+            quote = '"'
+        else:
+            quote = "'"
+        out.write(quote)
+
+        i = 0
+        while i < len(proxy):
+            ch = proxy[i]
+            i += 1
+
+            # Escape quotes and backslashes
+            if ch == quote or ch == '\\':
+                out.write('\\')
+                out.write(ch)
+
+            #  Map special whitespace to '\t', \n', '\r'
+            elif ch == '\t':
+                out.write('\\t')
+            elif ch == '\n':
+                out.write('\\n')
+            elif ch == '\r':
+                out.write('\\r')
+
+            # Map non-printable US ASCII to '\xhh' */
+            elif ch < ' ' or ch == 0x7F:
+                out.write('\\x')
+                out.write(hexdigits[(ord(ch) >> 4) & 0x000F])
+                out.write(hexdigits[ord(ch) & 0x000F])
+
+            # Copy ASCII characters as-is
+            elif ord(ch) < 0x7F:
+                out.write(ch)
+
+            # Non-ASCII characters
+            else:
+                ucs = ch
+                ch2 = None
+                if sys.maxunicode < 0x10000:
+                    # If sizeof(Py_UNICODE) is 2 here (in gdb), join
+                    # surrogate pairs before calling _unichr_is_printable.
+                    if (i < len(proxy)
+                    and 0xD800 <= ord(ch) < 0xDC00 \
+                    and 0xDC00 <= ord(proxy[i]) <= 0xDFFF):
+                        ch2 = proxy[i]
+                        ucs = ch + ch2
+                        i += 1
+
+                # Unfortuately, Python 2's unicode type doesn't seem
+                # to expose the "isprintable" method
+                printable = _unichr_is_printable(ucs)
+                if printable:
+                    try:
+                        ucs.encode(ENCODING)
+                    except UnicodeEncodeError:
+                        printable = False
+
+                # Map Unicode whitespace and control characters
+                # (categories Z* and C* except ASCII space)
+                if not printable:
+                    if ch2 is not None:
+                        # Match Python 3's representation of non-printable
+                        # wide characters.
+                        code = (ord(ch) & 0x03FF) << 10
+                        code |= ord(ch2) & 0x03FF
+                        code += 0x00010000
+                    else:
+                        code = ord(ucs)
+
+                    # Map 8-bit characters to '\\xhh'
+                    if code <= 0xff:
+                        out.write('\\x')
+                        out.write(hexdigits[(code >> 4) & 0x000F])
+                        out.write(hexdigits[code & 0x000F])
+                    # Map 21-bit characters to '\U00xxxxxx'
+                    elif code >= 0x10000:
+                        out.write('\\U')
+                        out.write(hexdigits[(code >> 28) & 0x0000000F])
+                        out.write(hexdigits[(code >> 24) & 0x0000000F])
+                        out.write(hexdigits[(code >> 20) & 0x0000000F])
+                        out.write(hexdigits[(code >> 16) & 0x0000000F])
+                        out.write(hexdigits[(code >> 12) & 0x0000000F])
+                        out.write(hexdigits[(code >> 8) & 0x0000000F])
+                        out.write(hexdigits[(code >> 4) & 0x0000000F])
+                        out.write(hexdigits[code & 0x0000000F])
+                    # Map 16-bit characters to '\uxxxx'
+                    else:
+                        out.write('\\u')
+                        out.write(hexdigits[(code >> 12) & 0x000F])
+                        out.write(hexdigits[(code >> 8) & 0x000F])
+                        out.write(hexdigits[(code >> 4) & 0x000F])
+                        out.write(hexdigits[code & 0x000F])
+                else:
+                    # Copy characters as-is
+                    out.write(ch)
+                    if ch2 is not None:
+                        out.write(ch2)
+
+        out.write(quote)
+
+
+
+
+def int_from_int(gdbval):
+    return int(str(gdbval))
+
+
+def stringify(val):
+    # TODO: repr() puts everything on one line; pformat can be nicer, but
+    # can lead to v.long results; this function isolates the choice
+    if True:
+        return repr(val)
+    else:
+        from pprint import pformat
+        return pformat(val)
+
+
+class PyObjectPtrPrinter:
+    "Prints a (PyObject*)"
+
+    def __init__ (self, gdbval):
+        self.gdbval = gdbval
+
+    def to_string (self):
+        pyop = PyObjectPtr.from_pyobject_ptr(self.gdbval)
+        if True:
+            return pyop.get_truncated_repr(MAX_OUTPUT_LEN)
+        else:
+            # Generate full proxy value then stringify it.
+            # Doing so could be expensive
+            proxyval = pyop.proxyval(set())
+            return stringify(proxyval)
+
+
+def pretty_printer_lookup(gdbval):
+    type = gdbval.type.unqualified()
+    if type.code == gdb.TYPE_CODE_PTR:
+        type = type.target().unqualified()
+        # do this every time to allow new subclasses to "register"
+        # alternatively, we could use a metaclass to register all the typenames
+        classes = [PyObjectPtr]
+        classes.extend(PyObjectPtr.__subclasses__())
+        if str(type) in [cls._typename for cls in classes]:
+            return PyObjectPtrPrinter(gdbval)
+
+"""
+During development, I've been manually invoking the code in this way:
+(gdb) python
+
+import sys
+sys.path.append('/home/david/coding/python-gdb')
+import libpython
+end
+
+then reloading it after each edit like this:
+(gdb) python reload(libpython)
+
+The following code should ensure that the prettyprinter is registered
+if the code is autoloaded by gdb when visiting libpython.so, provided
+that this python file is installed to the same path as the library (or its
+.debug file) plus a "-gdb.py" suffix, e.g:
+  /usr/lib/libpython2.6.so.1.0-gdb.py
+  /usr/lib/debug/usr/lib/libpython2.6.so.1.0.debug-gdb.py
+"""
+def register (obj):
+    if obj == None:
+        obj = gdb
+
+    # Wire up the pretty-printer
+    obj.pretty_printers.append(pretty_printer_lookup)
+
+register (gdb.current_objfile ())
+
+
+
+# Unfortunately, the exact API exposed by the gdb module varies somewhat
+# from build to build
+# See http://bugs.python.org/issue8279?#msg102276
+
+class Frame(object):
+    '''
+    Wrapper for gdb.Frame, adding various methods
+    '''
+    def __init__(self, gdbframe):
+        self._gdbframe = gdbframe
+
+    def older(self):
+        older = self._gdbframe.older()
+        if older:
+            return Frame(older)
+        else:
+            return None
+
+    def newer(self):
+        newer = self._gdbframe.newer()
+        if newer:
+            return Frame(newer)
+        else:
+            return None
+
+    def select(self):
+        '''If supported, select this frame and return True; return False if unsupported
+
+        Not all builds have a gdb.Frame.select method; seems to be present on Fedora 12
+        onwards, but absent on Ubuntu buildbot'''
+        if not hasattr(self._gdbframe, 'select'):
+            print ('Unable to select frame: '
+                   'this build of gdb does not expose a gdb.Frame.select method')
+            return False
+        self._gdbframe.select()
+        return True
+
+    def get_index(self):
+        '''Calculate index of frame, starting at 0 for the newest frame within
+        this thread'''
+        index = 0
+        # Go down until you reach the newest frame:
+        iter_frame = self
+        while iter_frame.newer():
+            index += 1
+            iter_frame = iter_frame.newer()
+        return index
+
+    def is_evalframeex(self):
+        '''Is this a PyEval_EvalFrameEx frame?'''
+        if self._gdbframe.name() == 'PyEval_EvalFrameEx':
+            '''
+            I believe we also need to filter on the inline
+            struct frame_id.inline_depth, only regarding frames with
+            an inline depth of 0 as actually being this function
+
+            So we reject those with type gdb.INLINE_FRAME
+            '''
+            if self._gdbframe.type() == gdb.NORMAL_FRAME:
+                # We have a PyEval_EvalFrameEx frame:
+                return True
+
+        return False
+
+    def get_pyop(self):
+        try:
+            f = self._gdbframe.read_var('f')
+            return PyFrameObjectPtr.from_pyobject_ptr(f)
+        except ValueError:
+            return None
+
+    @classmethod
+    def get_selected_frame(cls):
+        _gdbframe = gdb.selected_frame()
+        if _gdbframe:
+            return Frame(_gdbframe)
+        return None
+
+    @classmethod
+    def get_selected_python_frame(cls):
+        '''Try to obtain the Frame for the python code in the selected frame,
+        or None'''
+        frame = cls.get_selected_frame()
+
+        while frame:
+            if frame.is_evalframeex():
+                return frame
+            frame = frame.older()
+
+        # Not found:
+        return None
+
+    def print_summary(self):
+        if self.is_evalframeex():
+            pyop = self.get_pyop()
+            if pyop:
+                line = pyop.get_truncated_repr(MAX_OUTPUT_LEN)
+                write_unicode(sys.stdout, '#%i %s\n' % (self.get_index(), line))
+                sys.stdout.write(pyop.current_line())
+            else:
+                sys.stdout.write('#%i (unable to read python frame information)\n' % self.get_index())
+        else:
+            sys.stdout.write('#%i\n' % self.get_index())
+
+class PyList(gdb.Command):
+    '''List the current Python source code, if any
+
+    Use
+       py-list START
+    to list at a different line number within the python source.
+
+    Use
+       py-list START, END
+    to list a specific range of lines within the python source.
+    '''
+
+    def __init__(self):
+        gdb.Command.__init__ (self,
+                              "py-list",
+                              gdb.COMMAND_FILES,
+                              gdb.COMPLETE_NONE)
+
+
+    def invoke(self, args, from_tty):
+        import re
+
+        start = None
+        end = None
+
+        m = re.match(r'\s*(\d+)\s*', args)
+        if m:
+            start = int(m.group(0))
+            end = start + 10
+
+        m = re.match(r'\s*(\d+)\s*,\s*(\d+)\s*', args)
+        if m:
+            start, end = map(int, m.groups())
+
+        frame = Frame.get_selected_python_frame()
+        if not frame:
+            print 'Unable to locate python frame'
+            return
+
+        pyop = frame.get_pyop()
+        if not pyop:
+            print 'Unable to read information on python frame'
+            return
+
+        filename = pyop.filename()
+        lineno = pyop.current_line_num()
+
+        if start is None:
+            start = lineno - 5
+            end = lineno + 5
+
+        if start<1:
+            start = 1
+
+        with open(os_fsencode(filename), 'r') as f:
+            all_lines = f.readlines()
+            # start and end are 1-based, all_lines is 0-based;
+            # so [start-1:end] as a python slice gives us [start, end] as a
+            # closed interval
+            for i, line in enumerate(all_lines[start-1:end]):
+                linestr = str(i+start)
+                # Highlight current line:
+                if i + start == lineno:
+                    linestr = '>' + linestr
+                sys.stdout.write('%4s    %s' % (linestr, line))
+
+
+# ...and register the command:
+PyList()
+
+def move_in_stack(move_up):
+    '''Move up or down the stack (for the py-up/py-down command)'''
+    frame = Frame.get_selected_python_frame()
+    while frame:
+        if move_up:
+            iter_frame = frame.older()
+        else:
+            iter_frame = frame.newer()
+
+        if not iter_frame:
+            break
+
+        if iter_frame.is_evalframeex():
+            # Result:
+            if iter_frame.select():
+                iter_frame.print_summary()
+            return
+
+        frame = iter_frame
+
+    if move_up:
+        print 'Unable to find an older python frame'
+    else:
+        print 'Unable to find a newer python frame'
+
+class PyUp(gdb.Command):
+    'Select and print the python stack frame that called this one (if any)'
+    def __init__(self):
+        gdb.Command.__init__ (self,
+                              "py-up",
+                              gdb.COMMAND_STACK,
+                              gdb.COMPLETE_NONE)
+
+
+    def invoke(self, args, from_tty):
+        move_in_stack(move_up=True)
+
+class PyDown(gdb.Command):
+    'Select and print the python stack frame called by this one (if any)'
+    def __init__(self):
+        gdb.Command.__init__ (self,
+                              "py-down",
+                              gdb.COMMAND_STACK,
+                              gdb.COMPLETE_NONE)
+
+
+    def invoke(self, args, from_tty):
+        move_in_stack(move_up=False)
+
+# Not all builds of gdb have gdb.Frame.select
+if hasattr(gdb.Frame, 'select'):
+    PyUp()
+    PyDown()
+
+class PyBacktrace(gdb.Command):
+    'Display the current python frame and all the frames within its call stack (if any)'
+    def __init__(self):
+        gdb.Command.__init__ (self,
+                              "py-bt",
+                              gdb.COMMAND_STACK,
+                              gdb.COMPLETE_NONE)
+
+
+    def invoke(self, args, from_tty):
+        frame = Frame.get_selected_python_frame()
+        while frame:
+            if frame.is_evalframeex():
+                frame.print_summary()
+            frame = frame.older()
+
+PyBacktrace()
+
+class PyPrint(gdb.Command):
+    'Look up the given python variable name, and print it'
+    def __init__(self):
+        gdb.Command.__init__ (self,
+                              "py-print",
+                              gdb.COMMAND_DATA,
+                              gdb.COMPLETE_NONE)
+
+
+    def invoke(self, args, from_tty):
+        name = str(args)
+
+        frame = Frame.get_selected_python_frame()
+        if not frame:
+            print 'Unable to locate python frame'
+            return
+
+        pyop_frame = frame.get_pyop()
+        if not pyop_frame:
+            print 'Unable to read information on python frame'
+            return
+
+        pyop_var, scope = pyop_frame.get_var_by_name(name)
+
+        if pyop_var:
+            print ('%s %r = %s'
+                   % (scope,
+                      name,
+                      pyop_var.get_truncated_repr(MAX_OUTPUT_LEN)))
+        else:
+            print '%r not found' % name
+
+PyPrint()
+
+class PyLocals(gdb.Command):
+    'Look up the given python variable name, and print it'
+
+    def invoke(self, args, from_tty):
+        name = str(args)
+
+        frame = Frame.get_selected_python_frame()
+        if not frame:
+            print 'Unable to locate python frame'
+            return
+
+        pyop_frame = frame.get_pyop()
+        if not pyop_frame:
+            print 'Unable to read information on python frame'
+            return
+
+        namespace = self.get_namespace(pyop_frame)
+        namespace = [(name.proxyval(set()), val) for name, val in namespace]
+        
+        if namespace:
+            name, val = max(namespace, key=lambda (name, val): len(name))
+            max_name_length = len(name)
+            
+            for name, pyop_value in namespace:
+                value = pyop_value.get_truncated_repr(MAX_OUTPUT_LEN)
+                print ('%-*s = %s' % (max_name_length, name, value))
+
+    def get_namespace(self, pyop_frame):
+        return pyop_frame.iter_locals()
+
+
+class PyGlobals(PyLocals):
+    'List all the globals in the currently select Python frame'
+    
+    def get_namespace(self, pyop_frame):
+        return pyop_frame.iter_globals()
+
+
+PyLocals("py-locals", gdb.COMMAND_DATA, gdb.COMPLETE_NONE)
+PyGlobals("py-globals", gdb.COMMAND_DATA, gdb.COMPLETE_NONE)
+
+
+class PyNameEquals(gdb.Function):
+    
+    def _get_pycurframe_attr(self, attr):
+        frame = Frame(gdb.selected_frame())
+        if frame.is_evalframeex():
+            pyframe = frame.get_pyop()
+            if pyframe is None:
+                return None
+            
+            return getattr(pyframe, attr).proxyval(set())
+            
+        return None
+    
+    def invoke(self, funcname):
+        attr = self._get_pycurframe_attr('co_name')
+        return attr is not None and attr == funcname.string()
+
+PyNameEquals("pyname_equals")
+
+
+class PyModEquals(PyNameEquals):
+    
+    def invoke(self, modname):
+        attr = self._get_pycurframe_attr('co_filename')
+        if attr is not None:
+            filename, ext = os.path.splitext(os.path.basename(attr))
+            return filename == modname.string()
+        return False
+
+PyModEquals("pymod_equals")
+
+
+class PyBreak(gdb.Command):
+    """
+    Set a Python breakpoint. Examples:
+    
+    Break on any function or method named 'func' in module 'modname'
+            
+        py-break modname.func 
+        
+    Break on any function or method named 'func'
+        
+        py-break func
+    """
+    
+    def invoke(self, funcname, from_tty):
+        if '.' in funcname:
+            modname, dot, funcname = funcname.rpartition('.')
+            cond = '$pyname_equals("%s") && $pymod_equals("%s")' % (funcname, 
+                                                                    modname)
+        else:
+            cond = '$pyname_equals("%s")' % funcname
+
+        gdb.execute('break PyEval_EvalFrameEx if ' + cond)
+
+PyBreak("py-break", gdb.COMMAND_RUNNING, gdb.COMPLETE_NONE)
+
+
+class _LoggingState(object):
+    """
+    State that helps to provide a reentrant gdb.execute() function.
+    """
+    
+    def __init__(self):
+        self.fd, self.filename = tempfile.mkstemp()
+        self.file = os.fdopen(self.fd, 'r+')
+        _execute("set logging file %s" % self.filename)
+        self.file_position_stack = []
+        
+        atexit.register(os.close, self.fd)
+        atexit.register(os.remove, self.filename)
+        
+    def __enter__(self):
+        if not self.file_position_stack:
+            _execute("set logging redirect on")
+            _execute("set logging on")
+            _execute("set pagination off")
+        
+        self.file_position_stack.append(os.fstat(self.fd).st_size)
+        return self
+    
+    def getoutput(self):
+        gdb.flush()
+        self.file.seek(self.file_position_stack[-1])
+        result = self.file.read()
+        return result
+        
+    def __exit__(self, exc_type, exc_val, tb):
+        startpos = self.file_position_stack.pop()
+        self.file.seek(startpos)
+        self.file.truncate()
+        if not self.file_position_stack:
+            _execute("set logging off")
+            _execute("set logging redirect off")
+            _execute("set pagination on")
+
+
+def execute(command, from_tty=False, to_string=False):
+    """
+    Replace gdb.execute() with this function and have it accept a 'to_string'
+    argument (new in 7.2). Have it properly capture stderr also. Ensure 
+    reentrancy.
+    """
+    if to_string:
+        with _logging_state as state:
+            _execute(command, from_tty)
+            return state.getoutput()
+    else:
+        _execute(command, from_tty)
+
+
+_execute = gdb.execute
+gdb.execute = execute
+_logging_state = _LoggingState()
+
+
+def get_selected_inferior():
+    """
+    Return the selected inferior in gdb.
+    """
+    # Woooh, another bug in gdb! Is there an end in sight?
+    # http://sourceware.org/bugzilla/show_bug.cgi?id=12212
+    return gdb.inferiors()[0]
+    
+    selected_thread = gdb.selected_thread()
+    
+    for inferior in gdb.inferiors():
+        for thread in inferior.threads():
+            if thread == selected_thread:
+                return inferior
+
+
+class GenericCodeStepper(gdb.Command):
+    """
+    Superclass for code stepping. Subclasses must implement the following 
+    methods:
+        
+        lineno(frame)
+            tells the current line number (only called for a relevant frame)
+        
+        is_relevant_function(frame)
+            tells whether we care about frame 'frame'
+        
+        get_source_line(frame)
+            get the line of source code for the current line (only called for a
+            relevant frame). If the source code cannot be retrieved this 
+            function should return None
+        
+        static_break_functions() 
+            returns an iterable of function names that are considered relevant 
+            and should halt step-into execution. This is needed to provide a 
+            performing step-into
+      
+        runtime_break_functions 
+            list of functions that we should break into depending on the 
+            context
+
+    This class provides an 'invoke' method that invokes a 'step' or 'step-over'
+    depending on the 'stepinto' argument.
+    """
+    
+    stepper = False
+    static_breakpoints = {}
+    runtime_breakpoints = {}
+    
+    def __init__(self, name, stepinto=False):
+        super(GenericCodeStepper, self).__init__(name, 
+                                                 gdb.COMMAND_RUNNING,
+                                                 gdb.COMPLETE_NONE)
+        self.stepinto = stepinto
+
+    def _break_func(self, funcname):
+        result = gdb.execute('break %s' % funcname, to_string=True)
+        return re.search(r'Breakpoint (\d+)', result).group(1)
+
+    def init_breakpoints(self):
+        """
+        Keep all breakpoints around and simply disable/enable them each time
+        we are stepping. We need this because if you set and delete a 
+        breakpoint, gdb will not repeat your command (this is due to 'delete').
+        Why? I'm buggered if I know. To further annoy us, we can't use the 
+        breakpoint API because there's no option to make breakpoint setting 
+        silent.
+        So now! We may have an insane amount of breakpoints to list when the
+        user does 'info breakpoints' :(
+        
+        This method must be called whenever the list of functions we should
+        step into changes. It can be called on any GenericCodeStepper instance.
+        """
+        break_funcs = set(self.static_break_functions())
+        
+        for funcname in break_funcs:
+            if funcname not in self.static_breakpoints:
+                try:
+                    gdb.Breakpoint('', gdb.BP_BREAKPOINT, internal=True)
+                except (AttributeError, TypeError):
+                    # gdb.Breakpoint does not take an 'internal' argument, or
+                    # gdb.Breakpoint does not exist.
+                    breakpoint = self._break_func(funcname)
+                except RuntimeError:
+                    # gdb.Breakpoint does take an 'internal' argument, use it
+                    # and hide output
+                    result = gdb.execute(
+                        "python bp = gdb.Breakpoint(%r, gdb.BP_BREAKPOINT, internal=True); "
+                               "print bp.number", 
+                        to_string=True)
+                    
+                    breakpoint = int(result)
+
+                self.static_breakpoints[funcname] = breakpoint
+        
+        for bp in set(self.static_breakpoints) - break_funcs:
+            gdb.execute("delete " + self.static_breakpoints[bp])
+        
+        self.disable_breakpoints()
+
+    def enable_breakpoints(self):
+        for bp in self.static_breakpoints.itervalues():
+            gdb.execute('enable ' + bp)
+        
+        runtime_break_functions = self.runtime_break_functions()
+        if runtime_break_functions is None:
+            return
+            
+        for funcname in runtime_break_functions:
+            if (funcname not in self.static_breakpoints and 
+                funcname not in self.runtime_breakpoints):
+                self.runtime_breakpoints[funcname] = self._break_func(funcname)
+            elif funcname in self.runtime_breakpoints:
+                gdb.execute('enable ' + self.runtime_breakpoints[funcname])
+            
+    def disable_breakpoints(self):
+        chain = itertools.chain(self.static_breakpoints.itervalues(),
+                                self.runtime_breakpoints.itervalues())
+        for bp in chain:
+            gdb.execute('disable ' + bp)
+    
+    def runtime_break_functions(self):
+        """
+        Implement this if the list of step-into functions depends on the 
+        context.
+        """
+    
+    def stopped(self, result):
+        match = re.search('^Program received signal .*', result, re.MULTILINE)
+        if match:
+            return match.group(0)
+        elif get_selected_inferior().pid == 0:
+            return result
+        else:
+            return None
+        
+    def _stackdepth(self, frame):
+        depth = 0
+        while frame:
+            frame = frame.older()
+            depth += 1
+            
+        return depth
+    
+    def finish_executing(self, result):
+        """
+        After doing some kind of code running in the inferior, print the line
+        of source code or the result of the last executed gdb command (passed
+        in as the `result` argument).
+        """
+        result = self.stopped(result)
+        if result:
+            print result.strip()
+            # check whether the program was killed by a signal, it should still
+            # have a stack.
+            try:
+                frame = gdb.selected_frame()
+            except RuntimeError:
+                pass
+            else:
+                print self.get_source_line(frame)
+        else:
+            frame = gdb.selected_frame()
+            output = None
+            
+            if self.is_relevant_function(frame):
+                output = self.get_source_line(frame)
+            
+            if output is None:
+                pframe = getattr(self, 'print_stackframe', None)
+                if pframe:
+                    pframe(frame, index=0)
+                else:
+                    print result.strip()
+            else:
+                print output
+    
+    def _finish(self):
+        """
+        Execute until the function returns (or until something else makes it 
+        stop)
+        """
+        if gdb.selected_frame().older() is not None:
+            return gdb.execute('finish', to_string=True)
+        else:
+            # outermost frame, continue
+            return gdb.execute('cont', to_string=True)
+    
+    def finish(self, *args):
+        """
+        Execute until the function returns to a relevant caller.
+        """
+        
+        while True:
+            result = self._finish()
+            
+            try:
+                frame = gdb.selected_frame()
+            except RuntimeError:
+                break
+            
+            hitbp = re.search(r'Breakpoint (\d+)', result)
+            is_relavant = self.is_relevant_function(frame)
+            if hitbp or is_relavant or self.stopped(result):
+                break
+            
+        self.finish_executing(result)
+    
+    def _step(self):
+        """
+        Do a single step or step-over. Returns the result of the last gdb
+        command that made execution stop.
+        """
+        if self.stepinto:
+            self.enable_breakpoints()
+        
+        beginframe = gdb.selected_frame()
+        beginline = self.lineno(beginframe)
+        if not self.stepinto:
+            depth = self._stackdepth(beginframe)
+        
+        newframe = beginframe
+        result = ''
+
+        while True:
+            if self.is_relevant_function(newframe):
+                result = gdb.execute('next', to_string=True)
+            else:
+                result = self._finish()
+            
+            if self.stopped(result):
+                break
+            
+            newframe = gdb.selected_frame()
+            is_relevant_function = self.is_relevant_function(newframe)
+            try:
+                framename = newframe.name()
+            except RuntimeError:
+                framename = None
+            
+            m = re.search(r'Breakpoint (\d+)', result)
+            if m:
+                bp = self.runtime_breakpoints.get(framename)
+                if bp is None or (m.group(1) == bp and is_relevant_function):
+                    # although we hit a breakpoint, we still need to check
+                    # that the function, in case hit by a runtime breakpoint,
+                    # is in the right context
+                    break
+            
+            if newframe != beginframe:
+                # new function
+                
+                if not self.stepinto:
+                    # see if we returned to the caller
+                    newdepth = self._stackdepth(newframe)
+                    is_relevant_function = (newdepth < depth and 
+                                            is_relevant_function)
+                
+                if is_relevant_function:
+                    break
+            else:
+                if self.lineno(newframe) > beginline:
+                    break
+        
+        if self.stepinto:
+            self.disable_breakpoints()
+
+        return result
+    
+    def step(self, *args):
+        return self.finish_executing(self._step())
+
+    def run(self, *args):
+        self.finish_executing(gdb.execute('run', to_string=True))
+    
+    def cont(self, *args):
+        self.finish_executing(gdb.execute('cont', to_string=True))
+
+
+class PythonCodeStepper(GenericCodeStepper):
+    
+    def pyframe(self, frame):
+        pyframe = Frame(frame).get_pyop()
+        if pyframe:
+            return pyframe
+        else:
+            raise gdb.GdbError(
+                "Unable to find the Python frame, run your code with a debug "
+                "build (configure with --with-pydebug or compile with -g).")
+        
+    def lineno(self, frame):
+        return self.pyframe(frame).current_line_num()
+    
+    def is_relevant_function(self, frame):
+        return Frame(frame).is_evalframeex()
+
+    def get_source_line(self, frame):
+        try:
+            pyframe = self.pyframe(frame)
+            return '%4d    %s' % (pyframe.current_line_num(), 
+                                  pyframe.current_line().rstrip())
+        except IOError, e:
+            return None
+    
+    def static_break_functions(self):
+        yield 'PyEval_EvalFrameEx'
+
+
+class PyStep(PythonCodeStepper):
+    "Step through Python code."
+    
+    invoke = PythonCodeStepper.step
+    
+class PyNext(PythonCodeStepper):
+    "Step-over Python code."
+    
+    invoke = PythonCodeStepper.step
+    
+class PyFinish(PythonCodeStepper):
+    "Execute until function returns to a caller."
+    
+    invoke = PythonCodeStepper.finish
+
+class PyRun(PythonCodeStepper):
+    "Run the program."
+    
+    invoke = PythonCodeStepper.run
+
+class PyCont(PythonCodeStepper):
+    
+    invoke = PythonCodeStepper.cont
+
+
+py_step = PyStep('py-step', stepinto=True)
+py_next = PyNext('py-next', stepinto=False)
+py_finish = PyFinish('py-finish')
+py_run = PyRun('py-run')
+py_cont = PyCont('py-cont')
+
+gdb.execute('set breakpoint pending on')
+py_step.init_breakpoints()
+
+Py_single_input = 256
+Py_file_input = 257
+Py_eval_input = 258
+
+def _pointervalue(gdbval):
+    """
+    Return the value of the pionter as a Python int. 
+    
+    gdbval.type must be a pointer type
+    """
+    # don't convert with int() as it will raise a RuntimeError
+    if gdbval.address is not None:
+        return long(gdbval.address)
+    else:
+        # the address attribute is None sometimes, in which case we can
+        # still convert the pointer to an int
+        return long(gdbval)
+
+def pointervalue(gdbval):
+    pointer = _pointervalue(gdbval)
+    try:
+        if pointer < 0:
+            raise gdb.GdbError("Negative pointer value, presumably a bug "
+                               "in gdb, aborting.")
+    except RuntimeError:
+        # work around yet another bug in gdb where you get random behaviour
+        # and tracebacks
+        pass
+        
+    return pointer
+
+class PythonCodeExecutor(object):
+        
+    def malloc(self, size):
+        chunk = (gdb.parse_and_eval("(void *) malloc((size_t) %d)" % size))
+        
+        pointer = pointervalue(chunk)
+        if pointer == 0:
+            raise gdb.GdbError("No memory could be allocated in the inferior.")
+        
+        return pointer
+        
+    def alloc_string(self, string):
+        pointer = self.malloc(len(string))
+        get_selected_inferior().write_memory(pointer, string)
+        
+        return pointer
+    
+    def alloc_pystring(self, string):
+        stringp = self.alloc_string(string)
+        PyString_FromStringAndSize = 'PyString_FromStringAndSize'
+        try:
+            gdb.parse_and_eval(PyString_FromStringAndSize)
+        except RuntimeError:
+            try:
+                gdb.parse_and_eval('PyUnicode_FromStringAndSize')
+            except RuntimeError:
+                PyString_FromStringAndSize = 'PyUnicodeUCS2_FromStringAndSize'
+            else:
+                PyString_FromStringAndSize = 'PyUnicode_FromStringAndSize'
+            
+        try:
+            result = gdb.parse_and_eval(
+                '(PyObject *) %s((char *) %d, (size_t) %d)' % (
+                            PyString_FromStringAndSize, stringp, len(string)))
+        finally:
+            self.free(stringp)
+        
+        pointer = pointervalue(result)
+        if pointer == 0:
+            raise gdb.GdbError("Unable to allocate Python string in "
+                               "the inferior.")
+        
+        return pointer
+        
+    def free(self, pointer):
+        gdb.parse_and_eval("free((void *) %d)" % pointer)
+    
+    def incref(self, pointer):
+        "Increment the reference count of a Python object in the inferior."
+        gdb.parse_and_eval('Py_IncRef((PyObject *) %d)' % pointer)
+    
+    def decref(self, pointer):
+        "Decrement the reference count of a Python object in the inferior."
+        # Py_DecRef is like Py_XDECREF, but a function. So we don't have
+        # to check for NULL. This should also decref all our allocated
+        # Python strings.
+        gdb.parse_and_eval('Py_DecRef((PyObject *) %d)' % pointer)
+    
+    def evalcode(self, code, input_type, global_dict=None, local_dict=None):
+        """
+        Evaluate python code `code` given as a string in the inferior and
+        return the result as a gdb.Value. Returns a new reference in the
+        inferior.
+        
+        Of course, executing any code in the inferior may be dangerous and may
+        leave the debuggee in an unsafe state or terminate it alltogether.
+        """
+        if '\0' in code:
+            raise gdb.GdbError("String contains NUL byte.")
+        
+        code += '\0'
+        
+        pointer = self.alloc_string(code)
+        
+        globalsp = pointervalue(global_dict)
+        localsp = pointervalue(local_dict)
+        
+        if globalsp == 0 or localsp == 0:
+            raise gdb.GdbError("Unable to obtain or create locals or globals.")
+        
+        code = """
+            PyRun_String(
+                (PyObject *) %(code)d,
+                (int) %(start)d,
+                (PyObject *) %(globals)s,
+                (PyObject *) %(locals)d)
+        """ % dict(code=pointer, start=input_type, 
+                   globals=globalsp, locals=localsp)
+        
+        with FetchAndRestoreError():
+            try:
+                self.decref(gdb.parse_and_eval(code))
+            finally:
+                self.free(pointer)
+
+
+class FetchAndRestoreError(PythonCodeExecutor):
+    """
+    Context manager that fetches the error indicator in the inferior and
+    restores it on exit.
+    """
+
+    def __init__(self):
+        self.sizeof_PyObjectPtr = gdb.lookup_type('PyObject').pointer().sizeof
+        self.pointer = self.malloc(self.sizeof_PyObjectPtr * 3)
+        
+        type = self.pointer
+        value = self.pointer + self.sizeof_PyObjectPtr
+        traceback = self.pointer + self.sizeof_PyObjectPtr * 2
+        
+        self.errstate = type, value, traceback
+        
+    def __enter__(self):
+        gdb.parse_and_eval("PyErr_Fetch(%d, %d, %d)" % self.errstate)
+    
+    def __exit__(self, *args):
+        if gdb.parse_and_eval("(int) PyErr_Occurred()"):
+            gdb.parse_and_eval("PyErr_Print()")
+        
+        pyerr_restore = ("PyErr_Restore("
+                            "(PyObject *) *%d,"
+                            "(PyObject *) *%d,"
+                            "(PyObject *) *%d)")
+        
+        try:
+            gdb.parse_and_eval(pyerr_restore % self.errstate)
+        finally:
+            self.free(self.pointer)
+
+
+class FixGdbCommand(gdb.Command):
+
+    def __init__(self, command, actual_command):
+        super(FixGdbCommand, self).__init__(command, gdb.COMMAND_DATA,
+                                            gdb.COMPLETE_NONE)
+        self.actual_command = actual_command
+        
+    def fix_gdb(self):
+        """
+        So, you must be wondering what the story is this time! Yeeees, indeed, 
+        I have quite the story for you! It seems that invoking either 'cy exec'
+        and 'py-exec' work perfectly fine, but after this gdb's python API is 
+        entirely broken. Some unset exception value is still set? 
+        sys.exc_clear() didn't help. A demonstration:
+        
+        (gdb) cy exec 'hello'
+        'hello'
+        (gdb) python gdb.execute('cont')
+        RuntimeError: Cannot convert value to int.
+        Error while executing Python code.
+        (gdb) python gdb.execute('cont')
+        [15148 refs]
+    
+        Program exited normally.
+        """
+        warnings.filterwarnings('ignore', r'.*', RuntimeWarning, 
+                                re.escape(__name__))
+        try:
+            long(gdb.parse_and_eval("(void *) 0")) == 0
+        except RuntimeError:
+            pass
+        # warnings.resetwarnings()
+    
+    def invoke(self, args, from_tty):
+        self.fix_gdb()
+        try:
+            gdb.execute('%s %s' % (self.actual_command, args))
+        except RuntimeError, e:
+            raise gdb.GdbError(str(e))
+        self.fix_gdb()
+
+
+class PyExec(gdb.Command):
+    
+    def readcode(self, expr):
+        if expr:
+            return expr, Py_single_input
+        else:
+            lines = []
+            while True:
+                try:
+                    line = raw_input('>')
+                except EOFError:
+                    break
+                else:
+                    if line.rstrip() == 'end':
+                        break
+                    
+                    lines.append(line)
+            
+            return '\n'.join(lines), Py_file_input
+        
+    def invoke(self, expr, from_tty):
+        expr, input_type = self.readcode(expr)
+        
+        executor = PythonCodeExecutor()
+        global_dict = gdb.parse_and_eval('PyEval_GetGlobals()')
+        local_dict = gdb.parse_and_eval('PyEval_GetLocals()')
+        
+        if pointervalue(global_dict) == 0 or pointervalue(local_dict) == 0:
+            raise gdb.GdbError("Unable to find the locals or globals of the "
+                               "most recent Python function (relative to the "
+                               "selected frame).")
+        
+        executor.evalcode(expr, input_type, global_dict, local_dict)
+
+py_exec = FixGdbCommand('py-exec', '-py-exec')
+_py_exec = PyExec("-py-exec", gdb.COMMAND_DATA, gdb.COMPLETE_NONE)
\ No newline at end of file

Cython/Distutils/build_ext.py

@@ -17,11 +17,55 @@ from distutils.dep_util import newer, newer_group
 from distutils import log
 from distutils.dir_util import mkpath
 from distutils.command import build_ext as _build_ext
+from distutils import sysconfig
 
 extension_name_re = _build_ext.extension_name_re
 
 show_compilers = _build_ext.show_compilers
 
+class Optimization(object):
+    def __init__(self):
+        self.flags = (
+            'OPT', 
+            'CFLAGS',
+            'CPPFLAGS',
+            'EXTRA_CFLAGS', 
+            'BASECFLAGS',
+            'PY_CFLAGS',
+        )
+        self.state = sysconfig.get_config_vars(*self.flags)
+        self.config_vars = sysconfig.get_config_vars()
+        
+        
+    def disable_optimization(self):
+        "disable optimization for the C or C++ compiler"
+        badoptions = ('-O1', '-O2', '-O3')
+        
+        for flag, option in zip(self.flags, self.state):
+            if option is not None:
+                L = [opt for opt in option.split() if opt not in badoptions]
+                self.config_vars[flag] = ' '.join(L)
+    
+    def restore_state(self):
+        "restore the original state"
+        for flag, option in zip(self.flags, self.state):
+            if option is not None:
+                self.config_vars[flag] = option
+
+
+optimization = Optimization()
+
+try:
+    any
+except NameError:
+    def any(it):
+        for x in it:
+            if x:
+                return True
+        
+        return False
+        
+
 class build_ext(_build_ext.build_ext):
 
     description = "build C/C++ and Cython extensions (compile/link to build directory)"
@@ -47,10 +91,13 @@ class build_ext(_build_ext.build_ext):
             "generate .pxi file for public declarations"),
         ('pyrex-directives=', None,
             "compiler directive overrides"),
+        ('pyrex-gdb', None,
+         "generate debug information for cygdb"),
         ])
 
     boolean_options.extend([
-        'pyrex-cplus', 'pyrex-create-listing', 'pyrex-line-directives', 'pyrex-c-in-temp'
+        'pyrex-cplus', 'pyrex-create-listing', 'pyrex-line-directives', 
+        'pyrex-c-in-temp', 'pyrex-gdb',
     ])
 
     def initialize_options(self):
@@ -62,6 +109,7 @@ class build_ext(_build_ext.build_ext):
         self.pyrex_directives = None
         self.pyrex_c_in_temp = 0
         self.pyrex_gen_pxi = 0
+        self.pyrex_gdb = False
 
     def finalize_options (self):
         _build_ext.build_ext.finalize_options(self)
@@ -74,9 +122,21 @@ class build_ext(_build_ext.build_ext):
             self.pyrex_directives = {}
     # finalize_options ()
     
+    def run(self):
+        # We have one shot at this before build_ext initializes the compiler.
+        # If --pyrex-gdb is in effect as a command line option or as option
+        # of any Extension module, disable optimization for the C or C++
+        # compiler.
+        if (self.pyrex_gdb or any([getattr(ext, 'pyrex_gdb', False) 
+                                       for ext in self.extensions])):
+            optimization.disable_optimization()
+        
+        _build_ext.build_ext.run(self)
+    
     def build_extensions(self):
         # First, sanity-check the 'extensions' list
         self.check_extensions_list(self.extensions)
+        
         for ext in self.extensions:
             ext.sources = self.cython_sources(ext.sources, ext)
             self.build_extension(ext)
@@ -128,7 +188,7 @@ class build_ext(_build_ext.build_ext):
         cplus = self.pyrex_cplus or getattr(extension, 'pyrex_cplus', 0) or \
                 (extension.language and extension.language.lower() == 'c++')
         pyrex_gen_pxi = self.pyrex_gen_pxi or getattr(extension, 'pyrex_gen_pxi', 0)
-
+        pyrex_gdb = self.pyrex_gdb or getattr(extension, 'pyrex_gdb', False)
         # Set up the include_path for the Cython compiler:
         #    1.    Start with the command line option.
         #    2.    Add in any (unique) paths from the extension
@@ -201,6 +261,10 @@ class build_ext(_build_ext.build_ext):
             if rebuild:
                 log.info("cythoning %s to %s", source, target)
                 self.mkpath(os.path.dirname(target))
+                if self.inplace:
+                    output_dir = os.curdir
+                else:
+                    output_dir = self.build_lib
                 options = CompilationOptions(pyrex_default_options, 
                     use_listing_file = create_listing,
                     include_path = includes,
@@ -208,7 +272,9 @@ class build_ext(_build_ext.build_ext):
                     output_file = target,
                     cplus = cplus,
                     emit_linenums = line_directives,
-                    generate_pxi = pyrex_gen_pxi)
+                    generate_pxi = pyrex_gen_pxi,
+                    output_dir = output_dir,
+                    gdb_debug = pyrex_gdb)
                 result = cython_compile(source, options=options,
                                         full_module_name=module_name)
             else:

Cython/Distutils/extension.py

@@ -31,6 +31,8 @@ class Extension(_Extension.Extension):
         put generated C files in temp directory.
     pyrex_gen_pxi : boolean
         generate .pxi file for public declarations
+    pyrex_gdb : boolean
+        generate Cython debug information for this extension for cygdb
     """
 
     # When adding arguments to this constructor, be sure to update
@@ -56,6 +58,7 @@ class Extension(_Extension.Extension):
             pyrex_cplus = 0,
             pyrex_c_in_temp = 0,
             pyrex_gen_pxi = 0,
+            pyrex_gdb = False,
             **kw):
 
         _Extension.Extension.__init__(self, name, sources,
@@ -81,6 +84,7 @@ class Extension(_Extension.Extension):
         self.pyrex_cplus = pyrex_cplus
         self.pyrex_c_in_temp = pyrex_c_in_temp
         self.pyrex_gen_pxi = pyrex_gen_pxi
+        self.pyrex_gdb = pyrex_gdb
 
 # class Extension
 

Cython/StringIOTree.py

@@ -11,6 +11,7 @@ class StringIOTree(object):
             stream = StringIO()
         self.stream = stream
         self.write = stream.write
+        self.markers = []
 
     def getvalue(self):
         content = [x.getvalue() for x in self.prepended_children]
@@ -31,6 +32,8 @@ class StringIOTree(object):
         # itself is empty -- this makes it ready for insertion
         if self.stream.tell():
             self.prepended_children.append(StringIOTree(self.stream))
+            self.prepended_children[-1].markers = self.markers
+            self.markers = []
             self.stream = StringIO()
             self.write = self.stream.write
 
@@ -59,6 +62,11 @@ class StringIOTree(object):
         self.prepended_children.append(other)
         return other
 
+    def allmarkers(self):
+        children = self.prepended_children
+        return [m for c in children for m in c.allmarkers()] + self.markers
+        
+
 __doc__ = r"""
 Implements a buffer with insertion points. When you know you need to
 "get back" to a place and write more later, simply call insertion_point()

Cython/Tests/TestStringIOTree.py

+import unittest
+
+from Cython import StringIOTree as stringtree
+
+code = """
+cdef int spam                   # line 1
+
+cdef ham():
+    a = 1
+    b = 2
+    c = 3
+    d = 4
+
+def eggs():
+    pass
+
+cpdef bacon():
+    print spam
+    print 'scotch'
+    print 'tea?'
+    print 'or coffee?'          # line 16
+"""
+
+linemap = dict(enumerate(code.splitlines()))
+
+class TestStringIOTree(unittest.TestCase):
+    
+    def setUp(self):
+        self.tree = stringtree.StringIOTree()
+    
+    def test_markers(self):
+        assert not self.tree.allmarkers()
+    
+    def test_insertion(self):
+        self.write_lines((1, 2, 3))
+        line_4_to_6_insertion_point = self.tree.insertion_point()
+        self.write_lines((7, 8))
+        line_9_to_13_insertion_point = self.tree.insertion_point()
+        self.write_lines((14, 15, 16))
+    
+        line_4_insertion_point = line_4_to_6_insertion_point.insertion_point()
+        self.write_lines((5, 6), tree=line_4_to_6_insertion_point)
+        
+        line_9_to_12_insertion_point = (
+            line_9_to_13_insertion_point.insertion_point())
+        self.write_line(13, tree=line_9_to_13_insertion_point)
+        
+        self.write_line(4, tree=line_4_insertion_point)
+        self.write_line(9, tree=line_9_to_12_insertion_point)
+        line_10_insertion_point = line_9_to_12_insertion_point.insertion_point()
+        self.write_line(11, tree=line_9_to_12_insertion_point)
+        self.write_line(10, tree=line_10_insertion_point)
+        self.write_line(12, tree=line_9_to_12_insertion_point)
+        
+        self.assertEqual(self.tree.allmarkers(), range(1, 17))
+        self.assertEqual(code.strip(), self.tree.getvalue().strip())
+        
+        
+    def write_lines(self, linenos, tree=None):
+        for lineno in linenos:
+            self.write_line(lineno, tree=tree)
+    
+    def write_line(self, lineno, tree=None):
+        if tree is None:
+            tree = self.tree
+        tree.markers.append(lineno)
+        tree.write(linemap[lineno] + '\n')
\ No newline at end of file

bin/cygdb

+#!/usr/bin/env python
+
+import sys
+
+from Cython.Debugger import Cygdb as cygdb
+
+if __name__ == '__main__':
+    cygdb.main()

cygdb.py

+#!/usr/bin/env python
+
+import sys
+
+from Cython.Debugger import Cygdb as cygdb
+
+if __name__ == '__main__':
+    cygdb.main()

runtests.py

@@ -343,15 +343,27 @@ class CythonCompileTestCase(unittest.TestCase):
         else:
             return geterrors()
 
-    def run_cython(self, test_directory, module, targetdir, incdir, annotate):
+    def run_cython(self, test_directory, module, targetdir, incdir, annotate,
+                   extra_compile_options=None):
         include_dirs = INCLUDE_DIRS[:]
         if incdir:
             include_dirs.append(incdir)
         source = self.find_module_source_file(
             os.path.join(test_directory, module + '.pyx'))
         target = os.path.join(targetdir, self.build_target_filename(module))
+        
+        if extra_compile_options is None:
+            extra_compile_options = {}
+        
+        try:
+            CompilationOptions
+        except NameError:
+            from Cython.Compiler.Main import CompilationOptions
+            from Cython.Compiler.Main import compile as cython_compile
+            from Cython.Compiler.Main import default_options
+        
         options = CompilationOptions(
-            pyrex_default_options,
+            default_options,
             include_path = include_dirs,
             output_file = target,
             annotate = annotate,
@@ -360,11 +372,13 @@ class CythonCompileTestCase(unittest.TestCase):
             language_level = self.language_level,
             generate_pxi = False,
             evaluate_tree_assertions = True,
+            **extra_compile_options
             )
         cython_compile(source, options=options,
                        full_module_name=module)
 
-    def run_distutils(self, test_directory, module, workdir, incdir):
+    def run_distutils(self, test_directory, module, workdir, incdir, 
+                      extra_extension_args=None):
         cwd = os.getcwd()
         os.chdir(workdir)
         try:
@@ -378,11 +392,16 @@ class CythonCompileTestCase(unittest.TestCase):
                 if match(module):
                     ext_include_dirs += get_additional_include_dirs()
             self.copy_related_files(test_directory, workdir, module)
+            
+            if extra_extension_args is None:
+                extra_extension_args = {}
+            
             extension = Extension(
                 module,
                 sources = self.find_source_files(workdir, module),
                 include_dirs = ext_include_dirs,
                 extra_compile_args = CFLAGS,
+                **extra_extension_args
                 )
             if self.language == 'cpp':
                 extension.language = 'c++'
@@ -625,6 +644,8 @@ class CythonUnitTestCase(CythonCompileTestCase):
         except Exception:
             pass
 
+include_debugger = sys.version_info[:2] > (2, 4)
+
 def collect_unittests(path, module_prefix, suite, selectors):
     def file_matches(filename):
         return filename.startswith("Test") and filename.endswith(".py")
@@ -634,7 +655,11 @@ def collect_unittests(path, module_prefix, suite, selectors):
 
     loader = unittest.TestLoader()
     
+    if include_debugger:
         skipped_dirs = []
+    else:
+        cython_dir = os.path.dirname(os.path.abspath(__file__))
+        skipped_dirs = [os.path.join(cython_dir, 'Cython', 'Debugger')]
 
     for dirpath, dirnames, filenames in os.walk(path):
         if dirpath != path and "__init__.py" not in filenames:
@@ -659,12 +684,22 @@ def collect_unittests(path, module_prefix, suite, selectors):
                         module = getattr(module, x)
                     suite.addTests([loader.loadTestsFromModule(module)])
 
+
+
 def collect_doctests(path, module_prefix, suite, selectors):
     def package_matches(dirname):
+        if dirname == 'Debugger' and not include_debugger:
+            return False
         return dirname not in ("Mac", "Distutils", "Plex")
     def file_matches(filename):
-        return (filename.endswith(".py") and not ('~' in filename
-                or '#' in filename or filename.startswith('.')))
+        filename, ext = os.path.splitext(filename)
+        blacklist = ['libcython', 'libpython', 'test_libcython_in_gdb', 
+                     'TestLibCython']
+        return (ext == '.py' and not
+                '~' in filename and not
+                '#' in filename and not
+                filename.startswith('.') and not
+                filename in blacklist)
     import doctest, types
     for dirpath, dirnames, filenames in os.walk(path):
         parentname = os.path.split(dirpath)[-1]

setup.py

@@ -70,6 +70,9 @@ else:
 # specific to setup
 setuptools_extra_args = {}
 
+# tells whether to include cygdb (the script and the Cython.Debugger package
+include_debugger = sys.version_info[:2] > (2, 4)
+
 if 'setuptools' in sys.modules:
     setuptools_extra_args['zip_safe'] = False
     setuptools_extra_args['entry_points'] = {
@@ -81,8 +84,12 @@ if 'setuptools' in sys.modules:
 else:
     if os.name == "posix":
         scripts = ["bin/cython"]
+        if include_debugger:
+            scripts.append('bin/cygdb')
     else:
         scripts = ["cython.py"]
+        if include_debugger:
+            scripts.append('cygdb.py')
 
 def compile_cython_modules(profile=False, compile_more=False, cython_with_refnanny=False):
     source_root = os.path.abspath(os.path.dirname(__file__))
@@ -249,6 +256,20 @@ setup_args.update(setuptools_extra_args)
 
 from Cython import __version__ as version
 
+packages = [
+    'Cython',
+    'Cython.Build',
+    'Cython.Compiler',
+    'Cython.Runtime',
+    'Cython.Distutils',
+    'Cython.Plex',
+    'Cython.Tests',
+    'Cython.Compiler.Tests',
+]
+
+if include_debugger:
+    packages.append('Cython.Debugger')
+
 setup(
   name = 'Cython',
   version = version,
@@ -289,17 +310,7 @@ setup(
   ],
 
   scripts = scripts,
-  packages=[
-    'Cython',
-    'Cython.Build',
-    'Cython.Compiler',
-    'Cython.Runtime',
-    'Cython.Distutils',
-    'Cython.Plex',
-
-    'Cython.Tests',
-    'Cython.Compiler.Tests',
-    ],
+  packages=packages,
 
   # pyximport
   py_modules = ["pyximport/__init__",