Re: [RFC PATCH libiberty] Fix infinite recursion in demangler

[Mark Wielaard <mjw at redhat dot com>]

On Wed, 2017-03-08 at 09:05 -0500, Nathan Sidwell wrote:
> thanks.  in case you'd not noticed Ian T's okayed my review.  so this is 
> good to go

Thanks. Markus pushed it including the testcases.

But there are still two testcase (not added, but attached below) that
are still failing (but now just don't demangle, not crash, so that is
progress). You might want to take a look at those since they seem
related to lambda functions: https://gcc.gnu.org/PR68700 and
https://gcc.gnu.org/PR70517
For both of these you can get a demangled symbol if you change the
recursion guard to be dc->d_printing > 2 (instead of 1). We aren't sure
these are valid mangled symbols though. They might represent bugs in the
mangler, not demangler.

Also Markus used Pedro's mangler/demangler dogfooding patch to generate
a list of mangled symbols gcc produces that the demangler cannot
demangle. None of these crash, but they do indicate a bug in either the
mangler or demangler code.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79976

Cheers,

Mark

#
# Test for allowing recursion when is_lambda_arg PR68700
_ZN8futurizeI13frozen_schemaE5applyIRZN7seastar7shardedIN7service13storage_proxyEE9invoke_onIZZNS6_22init_messaging_serviceEvENKUljN5utils4UUIDEE8_clEjSA_EUlOT_E_6futureIJS0_EEEET0_jSD_EUlvE_JEEESG_SD_DpOT0_
service::storage_proxy::init_messaging_service()::{lambda(unsigned int, utils::UUID)#10}::operator()(unsigned int, utils::UUID) const::{lambda(auto:1&&)#1} futurize<frozen_schema>::apply<future<frozen_schema> seastar::sharded<service::storage_proxy>::invoke_on<service::storage_proxy::init_messaging_service()::{lambda(unsigned int, utils::UUID)#10}::operator()(unsigned int, utils::UUID) const::{lambda(auto:1&&)#1}, future<frozen_schema> >(unsigned int, service::storage_proxy::init_messaging_service()::{lambda(unsigned int, utils::UUID)#10}::operator()(unsigned int, utils::UUID) const::{lambda(auto:1&&)#1})::{lambda()#1}&>(future<frozen_schema> seastar::sharded<service::storage_proxy>::invoke_on<service::storage_proxy::init_messaging_service()::{lambda(unsigned int, utils::UUID)#10}::operator()(unsigned int, utils::UUID) const::{lambda(auto:1&&)#1}, future<frozen_schema> >(unsigned int, service::storage_proxy::init_messaging_service()::{lambda(unsigned int, utils::UUID)#10}::operator()(unsigned int, utils::UUID) const::{lambda(auto:1&&)#1})::{lambda()#1}&)

#
# Test for allowing recursion when is_lambda_arg PR70517
_ZSt4moveIRZN11tconcurrent6futureIvE4thenIZ5awaitIS2_EDaOT_EUlRKS6_E_EENS1_INSt5decayIDTclfp_defpTEEE4typeEEES7_EUlvE_EONSt16remove_referenceIS6_E4typeES7_
std::remove_reference<tconcurrent::future<std::decay<decltype ({parm#1}(*this))>::type> tconcurrent::future<void>::then<auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}>(auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}&& const)::{lambda()#1}&>::type&& std::move<tconcurrent::future<std::decay<decltype ({parm#1}(*this))>::type> tconcurrent::future<void>::then<auto await<tconcurrent::future<void> >(tconcurrent::future<std::decay<decltype ({parm#1}(*this))>::type> tconcurrent::future<void>::then<auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}>(auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}&& const)::{lambda()#1}&)::{lambda(auto:1&& const&)#1}>(tconcurrent::future<std::decay<decltype ({parm#1}(*this))>::type> tconcurrent::future<void>::then<auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}>(auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}&& const)::{lambda()#1}& const)::{lambda()#1}&>(tconcurrent::future<std::decay<decltype ({parm#1}(*this))>::type> tconcurrent::future<void>::then<auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}>(auto await<tconcurrent::future<void> >(tconcurrent::future<void>&&)::{lambda(auto:1&& const&)#1}&& const)::{lambda()#1}& const)