From 113844d68e94f4e9c0e946db351ba7d3d4a1335a Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Fri, 24 Jun 2022 14:40:12 -0400 Subject: c++: Include -Woverloaded-virtual in -Wall [PR87729] This seems like a good warning to have in -Wall, as requested. But as pointed out in PR20423, some users want a warning only when a derived function doesn't override any base function. So let's put that lesser version in -Wall (and -Woverloaded-virtual=1) while leaving the semantics for the existing option the same. PR c++/87729 PR c++/20423 gcc/c-family/ChangeLog: * c.opt (Woverloaded-virtual): Add levels, include in -Wall. gcc/ChangeLog: * doc/invoke.texi: Document changes. gcc/cp/ChangeLog: * class.cc (warn_hidden): Handle -Woverloaded-virtual=1. gcc/testsuite/ChangeLog: * g++.dg/warn/Woverloaded-virt1.C: New test. * g++.dg/warn/Woverloaded-virt2.C: New test. --- gcc/cp/class.cc | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'gcc/cp/class.cc') diff --git a/gcc/cp/class.cc b/gcc/cp/class.cc index 3c195b3..17683f4 100644 --- a/gcc/cp/class.cc +++ b/gcc/cp/class.cc @@ -3034,6 +3034,7 @@ warn_hidden (tree t) continue; /* Remove any overridden functions. */ + bool seen_non_override = false; for (tree fndecl : ovl_range (fns)) { if (TREE_CODE (fndecl) == FUNCTION_DECL @@ -3045,20 +3046,28 @@ warn_hidden (tree t) for (size_t k = 0; k < base_fndecls.length (); k++) if (base_fndecls[k] && same_signature_p (fndecl, base_fndecls[k])) - base_fndecls[k] = NULL_TREE; + { + base_fndecls[k] = NULL_TREE; + goto next; + } } + seen_non_override = true; + next:; } + if (!seen_non_override && warn_overloaded_virtual == 1) + /* All the derived fns override base virtuals. */ + return; + /* Now give a warning for all base functions without overriders, as they are hidden. */ - tree base_fndecl; - FOR_EACH_VEC_ELT (base_fndecls, j, base_fndecl) + for (tree base_fndecl : base_fndecls) if (base_fndecl) { auto_diagnostic_group d; /* Here we know it is a hider, and no overrider exists. */ if (warning_at (location_of (base_fndecl), - OPT_Woverloaded_virtual, + OPT_Woverloaded_virtual_, "%qD was hidden", base_fndecl)) inform (location_of (fns), " by %qD", fns); } -- cgit v1.1