From 1d869ceb04573727e59be6518903133c8654069a Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Mon, 6 Mar 2023 15:33:45 -0500 Subject: [PATCH] c++: lambda mangling alias issues [PR107897] To: gcc-patches@gcc.gnu.org In 107897, by the time we are looking at the mangling clash, the alias has already been removed from the symbol table by analyze_functions, so we can't look at n->cpp_implicit_alias. So just assume that it's an alias if it's internal. In 108887 the problem is that removing the mangling alias from the symbol table confuses analyze_functions, because it ended up as first_analyzed somehow, so it becomes a dangling pointer. Fixed by clearing various flags to neutralize the alias. PR c++/107897 PR c++/108887 gcc/ChangeLog: * cgraph.h: Move reset() from cgraph_node to symtab_node. * cgraphunit.cc (symtab_node::reset): Adjust. gcc/cp/ChangeLog: * decl2.cc (record_mangling): Use symtab_node::reset. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-lambda3.C: Use -flto if supported. * g++.dg/cpp0x/lambda/lambda-mangle7.C: New test. --- gcc/cgraph.h | 16 ++--- gcc/cgraphunit.cc | 27 ++++--- gcc/cp/decl2.cc | 19 +++-- .../g++.dg/cpp0x/lambda/lambda-mangle7.C | 70 +++++++++++++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-lambda3.C | 1 + 5 files changed, 109 insertions(+), 24 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-mangle7.C diff --git a/gcc/cgraph.h b/gcc/cgraph.h index b5fc739f1b0..fb938470be9 100644 --- a/gcc/cgraph.h +++ b/gcc/cgraph.h @@ -149,6 +149,14 @@ public: cgraph/varpool node creation routines. */ void register_symbol (void); + /* As an GCC extension we allow redefinition of the function. The + semantics when both copies of bodies differ is not well defined. + We replace the old body with new body so in unit at a time mode + we always use new body, while in normal mode we may end up with + old body inlined into some functions and new body expanded and + inlined in others. */ + void reset (void); + /* Remove symbol from symbol table. */ void remove (void); @@ -1066,14 +1074,6 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public symtab_node /* Expand function specified by node. */ void expand (void); - /* As an GCC extension we allow redefinition of the function. The - semantics when both copies of bodies differ is not well defined. - We replace the old body with new body so in unit at a time mode - we always use new body, while in normal mode we may end up with - old body inlined into some functions and new body expanded and - inlined in others. */ - void reset (void); - /* Creates a wrapper from cgraph_node to TARGET node. Thunk is used for this kind of wrapper method. */ void create_wrapper (cgraph_node *target); diff --git a/gcc/cgraphunit.cc b/gcc/cgraphunit.cc index a972900900b..2bce529ac81 100644 --- a/gcc/cgraphunit.cc +++ b/gcc/cgraphunit.cc @@ -381,18 +381,9 @@ symbol_table::process_new_functions (void) body for expanding the function but this is difficult to do. */ void -cgraph_node::reset (void) +symtab_node::reset (void) { - /* If process is set, then we have already begun whole-unit analysis. - This is *not* testing for whether we've already emitted the function. - That case can be sort-of legitimately seen with real function redefinition - errors. I would argue that the front end should never present us with - such a case, but don't enforce that for now. */ - gcc_assert (!process); - /* Reset our data structures so we can analyze the function again. */ - inlined_to = NULL; - memset (&rtl, 0, sizeof (rtl)); analyzed = false; definition = false; alias = false; @@ -400,8 +391,22 @@ cgraph_node::reset (void) weakref = false; cpp_implicit_alias = false; - remove_callees (); remove_all_references (); + remove_from_same_comdat_group (); + + if (cgraph_node *cn = dyn_cast (this)) + { + /* If process is set, then we have already begun whole-unit analysis. + This is *not* testing for whether we've already emitted the function. + That case can be sort-of legitimately seen with real function + redefinition errors. I would argue that the front end should never + present us with such a case, but don't enforce that for now. */ + gcc_assert (!cn->process); + + memset (&cn->rtl, 0, sizeof (cn->rtl)); + cn->inlined_to = NULL; + cn->remove_callees (); + } } /* Return true when there are references to the node. INCLUDE_SELF is diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc index 387e24542cd..57713d2ffdc 100644 --- a/gcc/cp/decl2.cc +++ b/gcc/cp/decl2.cc @@ -4742,15 +4742,24 @@ record_mangling (tree decl, bool need_warning) = mangled_decls->find_slot_with_hash (id, IDENTIFIER_HASH_VALUE (id), INSERT); - /* If this is already an alias, remove the alias, because the real + /* If this is already an alias, cancel the alias, because the real decl takes precedence. */ if (*slot && DECL_ARTIFICIAL (*slot) && DECL_IGNORED_P (*slot)) - if (symtab_node *n = symtab_node::get (*slot)) - if (n->cpp_implicit_alias) + { + if (symtab_node *n = symtab_node::get (*slot)) { - n->remove (); - *slot = NULL_TREE; + if (n->cpp_implicit_alias) + /* Actually removing the node isn't safe if other code is already + holding a pointer to it, so just neutralize it. */ + n->reset (); } + else + /* analyze_functions might have already removed the alias from the + symbol table if it's internal. */ + gcc_checking_assert (!TREE_PUBLIC (*slot)); + + *slot = NULL_TREE; + } if (!*slot) *slot = decl; diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-mangle7.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-mangle7.C new file mode 100644 index 00000000000..c7946a2be08 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-mangle7.C @@ -0,0 +1,70 @@ +// PR c++/108887 +// { dg-do compile { target c++11 } } + +template struct integral_constant { + static constexpr int value = __v; +}; +using false_type = integral_constant; +template struct __result_of_impl; +template +struct __result_of_impl { + typedef decltype(0) type; +}; +template +struct __invoke_result + : __result_of_impl {}; +template +void __invoke_impl(_Fn __f, _Args... __args) { + __f(__args...); +} +template +void __invoke_r(_Callable __fn, _Args... __args) { + using __result = __invoke_result<_Args...>; + using __type = typename __result::type; + __invoke_impl<__type>(__fn, __args...); +} +struct QString { + QString(const char *); +}; +template class function; +template struct _Base_manager { + static _Functor _M_get_pointer(int) { __builtin_abort (); } +}; +template class _Function_handler; +template +struct _Function_handler<_Res(_ArgTypes...), _Functor> { + using _Base = _Base_manager<_Functor>; + static _Res _M_invoke(const int &__functor, _ArgTypes &&...__args) { + auto __trans_tmp_1 = _Base::_M_get_pointer(__functor); + __invoke_r<_Res>(__trans_tmp_1, __args...); + } +}; +template +struct function<_Res(_ArgTypes...)> { + template + using _Handler = _Function_handler<_Res(_ArgTypes...), _Functor>; + template function(_Functor) { + using _My_handler = _Handler<_Functor>; + _M_invoker = _My_handler::_M_invoke; + } + using _Invoker_type = _Res (*)(const int &, _ArgTypes &&...); + _Invoker_type _M_invoker; +}; +struct QRegularExpression { + QRegularExpression(QString); +}; +struct AbstractAccount { + void get(function, + function); +}; +struct AbstractTimelineModel { + AbstractAccount m_account; +}; +struct LinkPaginationTimelineModel : AbstractTimelineModel { + void fillTimeline(); +}; +void LinkPaginationTimelineModel::fillTimeline() { + [] {}; + m_account.get([](AbstractAccount *) { static QRegularExpression re(""); }, + [](AbstractAccount *) {}); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-lambda3.C b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda3.C index 291e451ca1a..a7cb6c5dece 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-lambda3.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda3.C @@ -1,4 +1,5 @@ // { dg-do run { target c++20 } } +// { dg-additional-options "-flto" { target lto } } (PR107897) template concept C1 = __is_same_as(T, int) -- 2.31.1