Here we weren't instantiating the enumerators because the arglist still had the template parameter for the generic lambda, so looking one up failed. We need to instantiate if the non-lambda enclosing scope is non-dependent.
Tested x86_64-pc-linux-gnu, applying to trunk. gcc/cp/ChangeLog: PR c++/95317 * pt.c (lookup_template_class_1): Do tsubst_enum when tsubsting a generic lambda. gcc/testsuite/ChangeLog: PR c++/95317 * g++.dg/cpp1y/lambda-generic-enum1.C: New test. --- gcc/cp/pt.c | 3 ++- gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C | 10 ++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index d6a8ede386d..41bc633cfce 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -10173,7 +10173,8 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context, = tree_cons (arglist, t, DECL_TEMPLATE_INSTANTIATIONS (found)); - if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type + if (TREE_CODE (template_type) == ENUMERAL_TYPE + && !uses_template_parms (current_nonlambda_scope ()) && !DECL_ALIAS_TEMPLATE_P (gen_tmpl)) /* Now that the type has been registered on the instantiations list, we set up the enumerators. Because the enumeration diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C new file mode 100644 index 00000000000..de15443bfcf --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C @@ -0,0 +1,10 @@ +// PR c++/95317 +// { dg-do compile { target c++14 } } + +template <typename> void fn1() { + [](auto) { + enum { VALUE }; + VALUE; + }; +} +int main() { fn1<void>; } base-commit: 7ebdef2076fda56cb4cffb941f6c2576f980f3b3 prerequisite-patch-id: 22fd889eedb29aa662bdfc0fcc38e7a1072b47b4 -- 2.27.0