[gcc r11-11096] libstdc++: Reformat Python code

[gcc r11-11096] libstdc++: Reformat Python code

[Jonathan Wakely]

https://gcc.gnu.org/g:31bc3abd2b5abefa94c26d86b16d7d3d27bb3557

commit r11-11096-g31bc3abd2b5abefa94c26d86b16d7d3d27bb3557
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Sep 28 14:54:59 2023 +0100

    libstdc++: Reformat Python code
    
    Some of these changes were suggested by autopep8's --aggressive
    option, others are for readability.
    
    Break long lines by splitting strings across multiple lines, or
    introducing local variables to hold results.
    
    Use raw strings for regular expressions, so that backslashes don't need
    to be escaped.
    
    libstdc++-v3/ChangeLog:
    
            * python/libstdcxx/v6/printers.py: Break long lines. Use raw
            strings for regular expressions. Add whitespace around
            operators.
            (is_member_of_namespace): Use isinstance to check type.
            (is_specialization_of): Likewise. Adjust template_name
            for versioned namespace instead of duplicating the re.match
            call.
            (StdExpAnyPrinter._string_types): New static method.
            (StdExpAnyPrinter.to_string): Use _string_types.
    
    (cherry picked from commit 6b5c3f9b8139d9eee358b354b35da0b757a0270d)

Diff:
---
 libstdc++-v3/python/libstdcxx/v6/printers.py | 73 ++++++++++++++++++----------
 1 file changed, 46 insertions(+), 27 deletions(-)

diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py b/libstdc++-v3/python/libstdcxx/v6/printers.py
index 081eec454dd..6d19c4f1be3 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -157,7 +157,7 @@ def is_member_of_namespace(typ, *namespaces):
     Test whether a type is a member of one of the specified namespaces.
     The type can be specified as a string or a gdb.Type object.
     """
-    if type(typ) is gdb.Type:
+    if isinstance(typ, gdb.Type):
         typ = str(typ)
     typ = strip_versioned_namespace(typ)
     for namespace in namespaces:
@@ -168,10 +168,10 @@ def is_member_of_namespace(typ, *namespaces):
 def is_specialization_of(x, template_name):
     "Test if a type is a given template instantiation."
     global _versioned_namespace
-    if type(x) is gdb.Type:
+    if isinstance(x, gdb.Type):
         x = x.tag
     if _versioned_namespace:
-        return re.match('^std::(%s)?%s<.*>$' % (_versioned_namespace, template_name), x) is not None
+        template_name = '(%s)?%s' % (_versioned_namespace, template_name)
     return re.match('^std::%s<.*>$' % template_name, x) is not None
 
 def strip_versioned_namespace(typename):
@@ -186,9 +186,9 @@ def strip_inline_namespaces(type_str):
     type_str = type_str.replace('std::__cxx11::', 'std::')
     expt_ns = 'std::experimental::'
     for lfts_ns in ('fundamentals_v1', 'fundamentals_v2'):
-        type_str = type_str.replace(expt_ns+lfts_ns+'::', expt_ns)
+        type_str = type_str.replace(expt_ns + lfts_ns + '::', expt_ns)
     fs_ns = expt_ns + 'filesystem::'
-    type_str = type_str.replace(fs_ns+'v1::', fs_ns)
+    type_str = type_str.replace(fs_ns + 'v1::', fs_ns)
     return type_str
 
 def get_template_arg_list(type_obj):
@@ -298,8 +298,9 @@ class UniquePointerPrinter:
     def children (self):
         return SmartPtrIterator(unique_ptr_get(self.val))
 
-    def to_string (self):
-        return ('std::unique_ptr<%s>' % (str(self.val.type.template_argument(0))))
+    def to_string(self):
+        t = self.val.type.template_argument(0)
+        return 'std::unique_ptr<{}>'.format(str(t))
 
 def get_value_from_aligned_membuf(buf, valtype):
     """Returns the value held in a __gnu_cxx::__aligned_membuf."""
@@ -519,7 +520,8 @@ class StdBitIteratorPrinter:
     def to_string(self):
         if not self.val['_M_p']:
             return 'non-dereferenceable iterator for std::vector<bool>'
-        return bool(self.val['_M_p'].dereference() & (1 << self.val['_M_offset']))
+        return bool(self.val['_M_p'].dereference()
+                    & (1 << self.val['_M_offset']))
 
 class StdBitReferencePrinter:
     "Print std::vector<bool>::reference"
@@ -1151,10 +1153,11 @@ class SingleObjContainerPrinter(object):
             return self.visualizer.children ()
         return self._contained (self.contained_value)
 
-    def display_hint (self):
-        # if contained value is a map we want to display in the same way
-        if hasattr (self.visualizer, 'children') and hasattr (self.visualizer, 'display_hint'):
-            return self.visualizer.display_hint ()
+    def display_hint(self):
+        if (hasattr(self.visualizer, 'children')
+                and hasattr(self.visualizer, 'display_hint')):
+            # If contained value is a map we want to display in the same way.
+            return self.visualizer.display_hint()
         return self.hint
 
 def function_pointer_to_name(f):
@@ -1185,7 +1188,8 @@ class StdExpAnyPrinter(SingleObjContainerPrinter):
 
     def __init__ (self, typename, val):
         self.typename = strip_versioned_namespace(typename)
-        self.typename = re.sub('^std::experimental::fundamentals_v\d::', 'std::experimental::', self.typename, 1)
+        self.typename = re.sub(r'^std::experimental::fundamentals_v\d::',
+                               'std::experimental::', self.typename, 1)
         self.val = val
         self.contained_type = None
         contained_value = None
@@ -1194,8 +1198,18 @@ class StdExpAnyPrinter(SingleObjContainerPrinter):
         if mgr != 0:
             func = function_pointer_to_name(mgr)
             if not func:
-                raise ValueError("Invalid function pointer in %s" % (self.typename))
-            rx = r"""({0}::_Manager_\w+<.*>)::_S_manage\((enum )?{0}::_Op, (const {0}|{0} const) ?\*, (union )?{0}::_Arg ?\*\)""".format(typename)
+                raise ValueError(
+                    "Invalid function pointer in %s" % (self.typename))
+            # We want to use this regular expression:
+            # T::_Manager_xxx<.*>::_S_manage\(T::_Op, const T\*, T::_Arg\*\)
+            # where T is std::any or std::experimental::any.
+            # But we need to account for variances in demangled names
+            # between GDB versions, e.g. 'enum T::_Op' instead of 'T::_Op'.
+            rx = (
+                r"({0}::_Manager_\w+<.*>)::_S_manage\("
+                r"(enum )?{0}::_Op, (const {0}|{0} const) ?\*, "
+                r"(union )?{0}::_Arg ?\*\)"
+            ).format(typename)
             m = re.match(rx, func)
             if not m:
                 raise ValueError("Unknown manager function in %s" % self.typename)
@@ -1203,7 +1217,7 @@ class StdExpAnyPrinter(SingleObjContainerPrinter):
             mgrname = m.group(1)
             # FIXME need to expand 'std::string' so that gdb.lookup_type works
             if 'std::string' in mgrname:
-                mgrname = re.sub("std::string(?!\w)", str(gdb.lookup_type('std::string').strip_typedefs()), m.group(1))
+                mgrname = re.sub(r"std::string(?!\w)", str(gdb.lookup_type('std::string').strip_typedefs()), m.group(1))
 
             mgrtype = gdb.lookup_type(mgrname)
             self.contained_type = mgrtype.template_argument(0)
@@ -1233,7 +1247,9 @@ class StdExpOptionalPrinter(SingleObjContainerPrinter):
     def __init__ (self, typename, val):
         valtype = self._recognize (val.type.template_argument(0))
         typename = strip_versioned_namespace(typename)
-        self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, typename, 1)
+        self.typename = re.sub(
+            r'^std::(experimental::|)(fundamentals_v\d::|)(.*)',
+            r'std::\1\3<%s>' % valtype, typename, 1)
         payload = val['_M_payload']
         if self.typename.startswith('std::experimental'):
             engaged = val['_M_engaged']
@@ -1431,7 +1447,7 @@ class StdPathPrinter:
                 # We can't access _Impl::_M_size because _Impl is incomplete
                 # so cast to int* to access the _M_size member at offset zero,
                 int_type = gdb.lookup_type('int')
-                cmpt_type = gdb.lookup_type(pathtype+'::_Cmpt')
+                cmpt_type = gdb.lookup_type(pathtype + '::_Cmpt')
                 char_type = gdb.lookup_type('char')
                 impl = impl.cast(int_type.pointer())
                 size = impl.dereference()
@@ -1503,8 +1519,8 @@ class StdPairPrinter:
 class StdCmpCatPrinter:
     "Print a comparison category object"
 
-    def __init__ (self, typename, val):
-        self.typename = typename[typename.rfind(':')+1:]
+    def __init__(self, typename, val):
+        self.typename = typename[typename.rfind(':') + 1:]
         self.val = val['_M_value']
 
     def to_string (self):
@@ -1555,14 +1571,15 @@ class StdErrorCodePrinter:
 
     @classmethod
     def _category_info(cls, cat):
-        "Return details of a std::error_category"
+        """Return details of a std::error_category."""
 
         name = None
         enum = None
         is_errno = False
 
         # Try these first, or we get "warning: RTTI symbol not found" when
-        # using cat.dynamic_type on the local class types for Net TS categories.
+        # using cat.dynamic_type on the local class types for Net TS
+        # categories.
         func, enum = cls._match_net_ts_category(cat)
         if func is not None:
             return (None, func, enum, is_errno)
@@ -1649,7 +1666,8 @@ class StdSpanPrinter:
     def __init__(self, typename, val):
         self.typename = strip_versioned_namespace(typename)
         self.val = val
-        if val.type.template_argument(1) == gdb.parse_and_eval('static_cast<std::size_t>(-1)'):
+        size_max = gdb.parse_and_eval('static_cast<std::size_t>(-1)')
+        if val.type.template_argument(1) == size_max:
             self.size = val['_M_extent']['_M_extent_value']
         else:
             self.size = val.type.template_argument(1)
@@ -1884,19 +1902,20 @@ def add_one_template_type_printer(obj, name, defargs):
       4: 'std::allocator<std::pair<const {0}, {1}> >' }
 
     """
-    printer = TemplateTypePrinter('std::'+name, defargs)
+    printer = TemplateTypePrinter('std::' + name, defargs)
     gdb.types.register_type_printer(obj, printer)
 
     # Add type printer for same type in debug namespace:
-    printer = TemplateTypePrinter('std::__debug::'+name, defargs)
+    printer = TemplateTypePrinter('std::__debug::' + name, defargs)
     gdb.types.register_type_printer(obj, printer)
 
     if _versioned_namespace:
         # Add second type printer for same type in versioned namespace:
         ns = 'std::' + _versioned_namespace
         # PR 86112 Cannot use dict comprehension here:
-        defargs = dict((n, d.replace('std::', ns)) for (n,d) in defargs.items())
-        printer = TemplateTypePrinter(ns+name, defargs)
+        defargs = dict((n, d.replace('std::', ns))
+                       for (n, d) in defargs.items())
+        printer = TemplateTypePrinter(ns + name, defargs)
         gdb.types.register_type_printer(obj, printer)
 
 class FilteringTypePrinter(object):