gdb libpython.py: Remove compatibility code (#105739)

Remove compatibility code for Python 2 and early Python 3 versions.

* Remove os_fsencode() reimplementation: use os.fsencode() directly.
  os.fsencode() was added to Python 3.2.
* Remove references to Python 2 and "Python 3": just say "Python".
* Remove outdated u'' string format: use '' instead.

Author: vstinner

Tools/gdb/libpython.py

@@ -111,26 +111,6 @@ def safe_range(val):
     # threshold in case the data was corrupted
     return range(safety_limit(int(val)))
 
-try:
-    os_fsencode = os.fsencode
-except AttributeError:
-    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
 
@@ -174,16 +154,12 @@ def __init__(self, gdbval, cast_to=None):
 
     def field(self, name):
         '''
-        Get the gdb.Value for the given field within the PyObject, coping with
-        some python 2 versus python 3 differences.
+        Get the gdb.Value for the given field within the PyObject.
 
         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:
+        In Python, 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*).
@@ -204,8 +180,7 @@ def field(self, 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.
+        Get a PyObjectPtr for the given PyObject* field within this PyObject.
         '''
         return PyObjectPtr.from_pyobject_ptr(self.field(name))
 
@@ -924,7 +899,7 @@ def proxyval(self, visited):
         return result
 
     def write_repr(self, out, visited):
-        # Write this out as a Python 3 int literal, i.e. without the "L" suffix
+        # Write this out as a Python int literal
         proxy = self.proxyval(visited)
         out.write("%s" % proxy)
 
@@ -1170,7 +1145,7 @@ def current_line(self):
 
         filename = self.filename()
         try:
-            with open(os_fsencode(filename), 'r', encoding="utf-8") as fp:
+            with open(os.fsencode(filename), 'r', encoding="utf-8") as fp:
                 lines = fp.readlines()
         except IOError:
             return None
@@ -1263,7 +1238,7 @@ def proxyval(self, visited):
             return set(members)
 
     def write_repr(self, out, visited):
-        # Emulate Python 3's set_repr
+        # Emulate Python's set_repr
         tp_name = self.safe_tp_name()
 
         # Guard against infinite loops:
@@ -1272,13 +1247,13 @@ def write_repr(self, out, visited):
             return
         visited.add(self.as_address())
 
-        # Python 3's set_repr special-cases the empty set:
+        # Python'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:
+        # Python uses {} for set literals:
         if tp_name != 'set':
             out.write(tp_name)
             out.write('(')
@@ -1309,13 +1284,13 @@ 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
+        # Write this out as a Python bytes literal, i.e. with a "b" prefix
 
-        # Get a PyStringObject* within the Python 2 gdb process:
+        # Get a PyStringObject* within the Python gdb process:
         proxy = self.proxyval(visited)
 
-        # Transliteration of Python 3's Objects/bytesobject.c:PyBytes_Repr
-        # to Python 2 code:
+        # Transliteration of Python's Objects/bytesobject.c:PyBytes_Repr
+        # to Python code:
         quote = "'"
         if "'" in proxy and not '"' in proxy:
             quote = '"'
@@ -1380,7 +1355,7 @@ class PyTypeObjectPtr(PyObjectPtr):
 
 
 def _unichr_is_printable(char):
-    # Logic adapted from Python 3's Tools/unicode/makeunicodedata.py
+    # Logic adapted from Python's Tools/unicode/makeunicodedata.py
     if char == u" ":
         return True
     import unicodedata
@@ -1416,17 +1391,17 @@ def proxyval(self, visited):
 
         # Convert the int code points to unicode characters, and generate a
         # local unicode instance.
-        result = u''.join(map(chr, code_points))
+        result = ''.join(map(chr, code_points))
         return result
 
     def write_repr(self, out, visited):
-        # Write this out as a Python 3 str literal, i.e. without a "u" prefix
+        # Write this out as a Python str literal
 
-        # Get a PyUnicodeObject* within the Python 2 gdb process:
+        # Get a PyUnicodeObject* within the Python gdb process:
         proxy = self.proxyval(visited)
 
-        # Transliteration of Python 3's Object/unicodeobject.c:unicode_repr
-        # to Python 2:
+        # Transliteration of Python's Object/unicodeobject.c:unicode_repr
+        # to Python:
         if "'" in proxy and '"' not in proxy:
             quote = '"'
         else:
@@ -1477,7 +1452,7 @@ def write_repr(self, out, visited):
                 # (categories Z* and C* except ASCII space)
                 if not printable:
                     if ch2 is not None:
-                        # Match Python 3's representation of non-printable
+                        # Match Python's representation of non-printable
                         # wide characters.
                         code = (ord(ch) & 0x03FF) << 10
                         code |= ord(ch2) & 0x03FF
@@ -1608,8 +1583,8 @@ def pretty_printer_lookup(gdbval):
 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
+  /usr/lib/libpython3.12.so.1.0-gdb.py
+  /usr/lib/debug/usr/lib/libpython3.12.so.1.0.debug-gdb.py
 """
 def register (obj):
     if obj is None:
@@ -1928,7 +1903,7 @@ def invoke(self, args, from_tty):
             start = 1
 
         try:
-            f = open(os_fsencode(filename), 'r', encoding="utf-8")
+            f = open(os.fsencode(filename), 'r', encoding="utf-8")
         except IOError as err:
             sys.stdout.write('Unable to open %s: %s\n'
                              % (filename, err))