From cb168f779c87c1e0c37d22ea82dfb93ff8c873bc Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Thu, 11 Feb 2021 10:59:54 -0500 Subject: [PATCH] c++: Fix ICE from op_unqualified_lookup [PR97582] In this testcase, we're crashing because the lookup of operator+ from within the generic lambda via lookup_name finds multiple bindings (C1::operator+ and C2::operator+) and returns a TREE_LIST thereof, something which op_unqualified_lookup (and push_operator_bindings) isn't prepared to handle. This patch extends op_unqualified_lookup and push_operator_bindings to handle such an ambiguous lookup result in the natural way. gcc/cp/ChangeLog: PR c++/97582 * name-lookup.c (op_unqualified_lookup): Handle an ambiguous lookup result by discarding it if the first element is a class-scope declaration, otherwise return it. (push_operator_bindings): Handle an ambiguous lookup result by doing push_local_binding on each element in the list. gcc/testsuite/ChangeLog: PR c++/97582 * g++.dg/cpp0x/lambda/lambda-template17.C: New test. --- gcc/cp/name-lookup.c | 14 +++++++++++--- gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template17.C | 12 ++++++++++++ 2 files changed, 23 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template17.C diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c index 1f4a7ac..1cd4f67 100644 --- a/gcc/cp/name-lookup.c +++ b/gcc/cp/name-lookup.c @@ -9219,11 +9219,15 @@ op_unqualified_lookup (tree fnname) /* Remember we found nothing! */ return error_mark_node; - tree d = is_overloaded_fn (fns) ? get_first_fn (fns) : fns; + tree d = fns; + if (TREE_CODE (d) == TREE_LIST) + d = TREE_VALUE (d); + if (is_overloaded_fn (d)) + d = get_first_fn (d); if (DECL_CLASS_SCOPE_P (d)) /* We don't need to remember class-scope functions or declarations, normal unqualified lookup will find them again. */ - fns = NULL_TREE; + return NULL_TREE; return fns; } @@ -9302,7 +9306,11 @@ push_operator_bindings () if (tree val = TREE_VALUE (binds)) { tree name = TREE_PURPOSE (binds); - push_local_binding (name, val, /*using*/true); + if (TREE_CODE (val) == TREE_LIST) + for (tree v = val; v; v = TREE_CHAIN (v)) + push_local_binding (name, TREE_VALUE (v), /*using*/true); + else + push_local_binding (name, val, /*using*/true); } } diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template17.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template17.C new file mode 100644 index 0000000..ac6c2e2 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template17.C @@ -0,0 +1,12 @@ +// PR c++/97582 +// { dg-do compile { target c++11 } } + +struct C1 { void operator+(); }; +struct C2 { void operator+(); }; +struct C3 : C1, C2 { + template void get() { [] (T x) { +x; }; } // { dg-error "ambiguous" } +}; + +template void C3::get(); // { dg-bogus "" } +template void C3::get(); // { dg-bogus "" } +template void C3::get(); // { dg-message "required from here" } -- 2.7.4