https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97219
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:1824da60663b4532199ecd051d8ba6da8995821d commit r12-8152-g1824da60663b4532199ecd051d8ba6da8995821d Author: Jason Merrill <ja...@redhat.com> Date: Wed Apr 13 16:42:25 2022 -0400 c++: local fn and generic lambda [PR97219] When instantiating the op() for a generic lambda, we can no longer do name lookup inside function scopes enclosing the lambda, so we need to remember the lookup result from processing the definition of the lambda. So the code in finish_call_expr to throw away the lookup result and instead look it up again at instantiation time needs to be adjusted. The approach I take is to only discard the result if the local extern comes from dependent scope; once the enclosing function template is instantiated and we're regenerating the lambda, then we can remember the result of lookup. We also need any default arguments to be instantiated at that point. PR c++/97219 gcc/cp/ChangeLog: * name-lookup.cc (dependent_local_decl_p): New. * cp-tree.h (dependent_local_decl_p): Declare. * semantics.cc (finish_call_expr): Use it. * pt.cc (tsubst_arg_types): Also substitute default args for local externs. gcc/testsuite/ChangeLog: * g++.dg/cpp1y/lambda-generic-local-fn1.C: New test.
