Hello, i changed the doc/invoke.texi like you suggested. Let me know If I missed anything!
Thank you, Matthew Beliveau On Mon, Jun 10, 2019 at 11:39 AM Martin Sebor <mse...@gmail.com> wrote: > > On 6/7/19 2:10 PM, Matthew Beliveau wrote: > > This patch adds a new warning option: Winaccessible-base, so that > > users are able to selectively control the warning. The warning is > > enabled by default; however, for the virtual bases' warning, it only > > triggers with -Wextra flag. > > With few exceptions the rest of the manual tends to refer to base > classes. I would suggest to do the same in this update as well: > > @@ -4800,6 +4801,22 @@ is only active when > @option{-fdelete-null-pointer-checks} is active, > which is enabled by optimizations in most targets. The precision of > the warnings depends on the optimization options used. > > +@item -Winaccessible-base @r{(C++, Objective-C++ only)} > +@opindex Winaccessible-base > +@opindex Wno-inaccessible-base > +Warn when a base is inaccessible in derived due to ambiguity. The > warning is > +enabled by default. Note the warning for virtual bases is enabled by the > +@option{-Wextra} option. > > > I.e., > > Warn when a base class is inaccessible in a class derived from > it due to ambiguity. > > Martin
Bootstrapped/regtested on x86_64-linux, ok for trunk? 2019-06-10 Matthew Beliveau <mbeli...@redhat.com> PR c++/90449 - add -Winaccessible-base option. * doc/invoke.texi (Winaccessible-base): Document. * c.opt (Winaccessible-base): Added new option. * class.c (warn_about_ambiguous_bases): Changed name to: maybe_warn_about_inaccessible_bases. (maybe_warn_about_inaccessible_bases): Implemented new Winaccessible-base warning option for both direct and virtual base warnings. (layout_class_type): Call to warn_about_ambiguous_bases changed to fit new name. * g++.dg/warn/Winaccessible-base-1.C: New file. * g++.dg/warn/Winaccessible-base-2.C: New file. * g++.dg/warn/Winaccessible-virtual-base-1.C: New file. * g++.dg/warn/Winaccessible-virtual-base-2.C: New file. diff --git gcc/c-family/c.opt gcc/c-family/c.opt index 046d489f7eb..144f6da15d6 100644 --- gcc/c-family/c.opt +++ gcc/c-family/c.opt @@ -625,6 +625,10 @@ Wignored-attributes C C++ Var(warn_ignored_attributes) Init(1) Warning Warn whenever attributes are ignored. +Winaccessible-base +C++ ObjC++ Var(warn_inaccessible_base) Init(1) Warning +Warn when a base is inaccessible in derived due to ambiguity. + Wincompatible-pointer-types C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning Warn when there is a conversion between pointers that have incompatible types. diff --git gcc/cp/class.c gcc/cp/class.c index a2585a61f96..9884cedc997 100644 --- gcc/cp/class.c +++ gcc/cp/class.c @@ -199,7 +199,7 @@ static int walk_subobject_offsets (tree, subobject_offset_fn, static int layout_conflict_p (tree, tree, splay_tree, int); static int splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2); -static void warn_about_ambiguous_bases (tree); +static void maybe_warn_about_inaccessible_bases (tree); static bool type_requires_array_cookie (tree); static bool base_derived_from (tree, tree); static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); @@ -6017,7 +6017,7 @@ end_of_class (tree t, bool include_virtuals_p) subobjects of U. */ static void -warn_about_ambiguous_bases (tree t) +maybe_warn_about_inaccessible_bases (tree t) { int i; vec<tree, va_gc> *vbases; @@ -6025,6 +6025,10 @@ warn_about_ambiguous_bases (tree t) tree binfo; tree base_binfo; + /* If not checking for warning then return early. */ + if (!warn_inaccessible_base) + return; + /* If there are no repeated bases, nothing can be ambiguous. */ if (!CLASSTYPE_REPEATED_BASE_P (t)) return; @@ -6036,8 +6040,8 @@ warn_about_ambiguous_bases (tree t) basetype = BINFO_TYPE (base_binfo); if (!uniquely_derived_from_p (basetype, t)) - warning (0, "direct base %qT inaccessible in %qT due to ambiguity", - basetype, t); + warning (OPT_Winaccessible_base, "direct base %qT inaccessible " + "in %qT due to ambiguity", basetype, t); } /* Check for ambiguous virtual bases. */ @@ -6048,8 +6052,8 @@ warn_about_ambiguous_bases (tree t) basetype = BINFO_TYPE (binfo); if (!uniquely_derived_from_p (basetype, t)) - warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due " - "to ambiguity", basetype, t); + warning (OPT_Winaccessible_base, "virtual base %qT inaccessible in " + "%qT due to ambiguity", basetype, t); } } @@ -6455,7 +6459,7 @@ layout_class_type (tree t, tree *virtuals_p) error ("size of type %qT is too large (%qE bytes)", t, TYPE_SIZE_UNIT (t)); /* Warn about bases that can't be talked about due to ambiguity. */ - warn_about_ambiguous_bases (t); + maybe_warn_about_inaccessible_bases (t); /* Now that we're done with layout, give the base fields the real types. */ for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi index 3e4f012b4fa..2877e7c69a1 100644 --- gcc/doc/invoke.texi +++ gcc/doc/invoke.texi @@ -317,6 +317,7 @@ Objective-C and Objective-C++ Dialects}. -Wignored-qualifiers -Wignored-attributes -Wincompatible-pointer-types @gol -Wimplicit -Wimplicit-fallthrough -Wimplicit-fallthrough=@var{n} @gol -Wimplicit-function-declaration -Wimplicit-int @gol +-Winaccessible-base @gol -Winit-self -Winline -Wno-int-conversion -Wint-in-bool-context @gol -Wno-int-to-pointer-cast -Winvalid-memory-model -Wno-invalid-offsetof @gol -Winvalid-pch -Wlarger-than=@var{byte-size} @gol @@ -4800,6 +4801,22 @@ is only active when @option{-fdelete-null-pointer-checks} is active, which is enabled by optimizations in most targets. The precision of the warnings depends on the optimization options used. +@item -Winaccessible-base @r{(C++, Objective-C++ only)} +@opindex Winaccessible-base +@opindex Wno-inaccessible-base +Warn when a base class is inaccessible in a class derived from it due to +ambiguity. The warning is enabled by default. Note the warning for virtual +bases is enabled by the @option{-Wextra} option. +@smallexample +@group +struct A @{ int a; @}; + +struct B : A @{ @}; + +struct C : B, A @{ @}; +@end group +@end smallexample + @item -Winit-self @r{(C, C++, Objective-C and Objective-C++ only)} @opindex Winit-self @opindex Wno-init-self diff --git gcc/testsuite/g++.dg/warn/Winaccessible-base-1.C gcc/testsuite/g++.dg/warn/Winaccessible-base-1.C new file mode 100644 index 00000000000..2e32b0b119f --- /dev/null +++ gcc/testsuite/g++.dg/warn/Winaccessible-base-1.C @@ -0,0 +1,7 @@ +// PR c++/90449 + +struct A { int a; }; + +struct B : A { }; + +struct C : B, A { }; // { dg-warning "direct base 'A' inaccessible in 'C' due to ambiguity" } diff --git gcc/testsuite/g++.dg/warn/Winaccessible-base-2.C gcc/testsuite/g++.dg/warn/Winaccessible-base-2.C new file mode 100644 index 00000000000..67bd740a763 --- /dev/null +++ gcc/testsuite/g++.dg/warn/Winaccessible-base-2.C @@ -0,0 +1,8 @@ +// PR c++/90449 +// { dg-options -Wno-inaccessible-base } + +struct A { int a; }; + +struct B : A { }; + +struct C : B, A { }; // { dg-bogus "direct base 'A' inaccessible in 'C' due to ambiguity" } diff --git gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-1.C gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-1.C new file mode 100644 index 00000000000..051fcc695fe --- /dev/null +++ gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-1.C @@ -0,0 +1,10 @@ +// PR c++/90449 +// { dg-options -Wextra } + +struct A { }; + +struct B : virtual A { }; + +struct C : A { }; + +struct D : B, C { }; // { dg-warning "virtual base 'A' inaccessible in 'D' due to ambiguity" } diff --git gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-2.C gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-2.C new file mode 100644 index 00000000000..eab9ec0e3d7 --- /dev/null +++ gcc/testsuite/g++.dg/warn/Winaccessible-virtual-base-2.C @@ -0,0 +1,10 @@ +// PR c++/90449 +// { dg-options "-Wextra -Wno-inaccessible-base" } + +struct A { }; + +struct B : virtual A { }; + +struct C : A { }; + +struct D : B, C { }; // { dg-bogus "virtual base 'A' inaccessible in 'D' due to ambiguity" }