Tested on x86_64-pc-linux-gnu, does this look OK for stage 1? -- >8 --
The PR68942 fix used the tf_conv flag to disable mark_used when substituting a FUNCTION_DECL callee of an ADL-enabled call. In this slightly more elaborate testcase, we end up prematurely calling mark_used anyway on the FUNCTION_DECL directly from the CALL_EXPR case of tsubst_expr during partial instantiation, leading to a bogus "use of deleted function" error. This patch fixes the general problem in a more robust way by ensuring the callee of an ADL-enabled call is wrapped in an OVERLOAD, so that tsubst_expr leaves it alone. PR c++/119034 PR c++/68942 gcc/cp/ChangeLog: * pt.cc (tsubst_expr) <case CALL_EXPR>: Revert PR68942 fix to * semantics.cc (finish_call_expr): Ensure the callee of an ADL-enabled call is wrapped in an OVERLOAD. gcc/testsuite/ChangeLog: * g++.dg/template/koenig13.C: New test. --- gcc/cp/pt.cc | 8 +------- gcc/cp/semantics.cc | 8 ++++++++ gcc/testsuite/g++.dg/template/koenig13.C | 16 ++++++++++++++++ 3 files changed, 25 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/g++.dg/template/koenig13.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 62d91a2dd15..4b69b26808b 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -21290,13 +21290,7 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl) /* Avoid error about taking the address of a constructor. */ function = TREE_OPERAND (function, 0); - tsubst_flags_t subcomplain = complain; - if (koenig_p && TREE_CODE (function) == FUNCTION_DECL) - /* When KOENIG_P, we don't want to mark_used the callee before - augmenting the overload set via ADL, so during this initial - substitution we disable mark_used by setting tf_conv (68942). */ - subcomplain |= tf_conv; - function = tsubst_expr (function, args, subcomplain, in_decl); + function = tsubst_expr (function, args, complain, in_decl); if (BASELINK_P (function)) qualified_p = true; diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index 7c7d3e3c432..9e13b690631 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -3321,6 +3321,14 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args, bool disallow_virtual, if (type_dependent_expression_p (fn) || any_type_dependent_arguments_p (*args)) { + if (koenig_p + && TREE_CODE (orig_fn) == FUNCTION_DECL + && !fndecl_built_in_p (orig_fn)) + /* For an ADL-enabled call where unqualified lookup found a + single non-template function, wrap it in an OVERLOAD so + that later substitution doesn't greedily mark the function + as used. */ + orig_fn = ovl_make (orig_fn, NULL_TREE); result = build_min_nt_call_vec (orig_fn, *args); SET_EXPR_LOCATION (result, cp_expr_loc_or_input_loc (fn)); KOENIG_LOOKUP_P (result) = koenig_p; diff --git a/gcc/testsuite/g++.dg/template/koenig13.C b/gcc/testsuite/g++.dg/template/koenig13.C new file mode 100644 index 00000000000..75c9d95df7e --- /dev/null +++ b/gcc/testsuite/g++.dg/template/koenig13.C @@ -0,0 +1,16 @@ +// PR c++/119034 +// { dg-do compile { target c++14 } } +// A version of koenig12.C involving partial instantiation of a generic lambda. + +void foo(...) = delete; + +template <class T> void lookup(T t) { [&](auto u) { foo(u); }(t); } + +namespace N { + struct A { }; + int foo(A); +} + +int main() { + lookup(N::A{}); +} -- 2.49.0.rc0