On Wed, 16 Nov 2022 at 06:04, François Dumont <frs.dum...@gmail.com> wrote: > > On 15/11/22 17:17, Jonathan Wakely wrote: > > On 06/10/22 19:38 +0200, François Dumont wrote: > >> Hi > >> > >> Looks like the previous patch was not enough. When using it in the > >> context of a build without dual abi and versioned namespace I started > >> having failures again. I guess I hadn't rebuild everything properly. > >> > >> This time I think the problem was in those lines: > >> > >> if self.type_obj == type_obj: > >> return strip_inline_namespaces(self.name) > >> > >> I've added a call to gdb.types.get_basic_type so that we do not compare > >> a type with its typedef. > >> > >> Thanks for the pointer to the doc ! > >> > >> Doing so I eventually use your code Jonathan to make FilteringTypeFilter > >> more specific to a given instantiation. > >> > >> libstdc++: Fix gdb FilteringTypePrinter > >> > >> Once we found a matching FilteringTypePrinter instance we look for > >> the associated > >> typedef and check that the returned Python Type is equal to the > >> Type to recognize. > >> But gdb Python Type includes properties to distinguish a typedef > >> from the actual > >> type. So use gdb.types.get_basic_type to check if we are indeed on > >> the same type. > >> > >> Additionnaly enhance FilteringTypePrinter matching mecanism by > >> introducing targ1 that, > >> if not None, will be used as the 1st template parameter. > >> > >> libstdc++-v3/ChangeLog: > >> > >> * python/libstdcxx/v6/printers.py (FilteringTypePrinter): > >> Rename 'match' field > >> 'template'. Add self.targ1 to specify the first template > >> parameter of the instantiation > >> to match. > >> (add_one_type_printer): Add targ1 optional parameter, > >> default to None. > >> Use gdb.types.get_basic_type to compare the type to > >> recognize and the type > >> returned from the typedef lookup. > >> (register_type_printers): Adapt calls to > >> add_one_type_printers. > >> > >> Tested under Linux x86_64 normal, version namespace with or without dual > >> abi. > >> > >> François > >> > >> diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py > >> b/libstdc++-v3/python/libstdcxx/v6/printers.py > >> index 0fa7805183e..52339b247d8 100644 > >> --- a/libstdc++-v3/python/libstdcxx/v6/printers.py > >> +++ b/libstdc++-v3/python/libstdcxx/v6/printers.py > >> @@ -2040,62 +2040,72 @@ def add_one_template_type_printer(obj, name, > >> defargs): > >> > >> class FilteringTypePrinter(object): > >> r""" > >> - A type printer that uses typedef names for common template > >> specializations. > >> + A type printer that uses typedef names for common template > >> instantiations. > >> > >> Args: > >> - match (str): The class template to recognize. > >> + template (str): The class template to recognize. > >> name (str): The typedef-name that will be used instead. > >> + targ1 (str): The first template argument. > >> + If arg1 is provided (not None), only template > >> instantiations with this type > >> + as the first template argument, e.g. if > >> template='basic_string<targ1' > >> > >> - Checks if a specialization of the class template 'match' is the > >> same type > >> + Checks if an instantiation of the class template 'template' is > >> the same type > >> as the typedef 'name', and prints it as 'name' instead. > >> > >> - e.g. if an instantiation of std::basic_istream<C, T> is the same > >> type as > >> + e.g. for template='basic_istream', name='istream', if any > >> instantiation of > >> + std::basic_istream<C, T> is the same type as std::istream then > >> print it as > >> + std::istream. > >> + > >> + e.g. for template='basic_istream', name='istream', targ1='char', > >> if any > >> + instantiation of std::basic_istream<char, T> is the same type as > >> std::istream then print it as std::istream. > >> """ > > > > These are template specializations, not instantiations. Please undo > > the changes to the comments, because the comments are 100% correct > > now, and would become wrong with this patch. > > > > template<class T, class U> struct foo { }; > > using F = foo<int, int>; // #1 > > template<class T> struct foo<T, void> { }; // #2 > > template<> struct foo<void, void> { }; // #3 > > > > #1 is a *specialization* of the class template foo. It is > > *instantiated* when you construct one or depend on its size, or its > > members. > > #2 is a *partial specialization* and #3 is an explicit specialization. > > But #1 is a speclialization, not an instantiation. > > > > Instantiation is a process that happens during compilation. A > > specialization is a type (or function, or variable) generated from a > > template by substituting arguments for the template parameters. The > > python type printer matches specializations. > > Lesson learned, thanks. > > Maybe comment on line 169 is wrong then. I think there is a clue in the > function name 'is_specialization_of' :-)
Good point! Thanks, I'll fix it. > > > > >> > >> - def __init__(self, match, name): > >> - self.match = match > >> + def __init__(self, template, name, targ1): > > > > Is there a reason to require targ1 here, instead of making it > > optional, by using =None as the default? > > In your original, and I know untested, proposal it was not working. > > The function add_one_type_printer was missing to pass its targ1 > parameter to the FilteringTypePrinter ctor but thanks to the default > value it was un-noticed by the interpreter. My untested patch had this, which adds it, doesn't it? -def add_one_type_printer(obj, match, name): - printer = FilteringTypePrinter('std::' + match, 'std::' + name) +def add_one_type_printer(obj, match, name, targ1 = None): + printer = FilteringTypePrinter('std::' + match, 'std::' + name, targ1) gdb.types.register_type_printer(obj, printer) if _versioned_namespace: ns = 'std::' + _versioned_namespace - printer = FilteringTypePrinter(ns + match, ns + name) + printer = FilteringTypePrinter(ns + match, ns + name, targ1) gdb.types.register_type_printer(obj, printer) I think FilteringTypePrinter should be usable without specifying None explicitly as the argument. Even if we don't actually use it that way today, it seems like a better API. If the argument is optional, then the idiomatic way to express that is to give it a default, not require None to be passed. I'll add that default argument, but first I need to figure out why I'm seeing new failures for libfundts.cc with -D_GLIBCXX_USE_CXX11_ABI=0. Your patch has introduced this new error: $12 = Python Exception <class 'gdb.error'>: No type named std::experimental::fundamentals_v1::any::_Manager_internal<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >>. got: $12 = Python Exception <class 'gdb.error'>: No type named std::experimental::fundamentals_v1::any::_Manager_internal<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >>. FAIL: libstdc++-prettyprinters/libfundts.cc print as > So I removed it as useless > and redundant with this function default value. > > > > > > > > >> + self.template = template > >> self.name = name > >> + self.targ1 = targ1 > >> self.enabled = True > >> > >> class _recognizer(object): > >> "The recognizer class for FilteringTypePrinter." > >> > >> - def __init__(self, match, name): > >> - self.match = match > >> + def __init__(self, template, name, targ1): > >> + self.template = template > >> self.name = name > >> + self.targ1 = targ1 > >> self.type_obj = None > >> > >> def recognize(self, type_obj): > >> """ > >> - If type_obj starts with self.match and is the same type as > >> + If type_obj starts with self.template and is the same > >> type as > >> self.name then return self.name, otherwise None. > >> """ > >> if type_obj.tag is None: > >> return None > >> > >> if self.type_obj is None: > >> - if not type_obj.tag.startswith(self.match): > >> + if self.targ1 is not None: > >> + if not > >> type_obj.tag.startswith('{}<{}'.format(self.template, self.targ1)): > > > > I wonder if we should make targ1 a gdb.Type object, not just a string. > > That seems like it would be better. The add_on_type_printer function > > could still accept a string, and then call gdb.lookup_type(targ1) to > > get a gdb.Type. We can change that later though. > > > > OK for trunk with the comments fixed to say "specialization" again. > > > Now committed. >