| Message ID | 20230712184747.3213450-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: non-standalone surrogate call template | expand |
On 7/12/23 14:47, Patrick Palka wrote: > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk? There might be an existing PR for this issue but Bugzilla search > seems to be timing out for me currently. OK. > -- >8 -- > > I noticed we were accidentally preventing ourselves from considering > a pointer/reference-to-function conversion function template if it's > not the first conversion function that's considered, which for the > testcase below resulted in us accepting the B call but not the A call > despite the only difference between A and B being the order of member > declarations. This patch fixes this so that the outcome of overload > resolution doesn't arbitrarily depend on declaration order in this > situation. > > gcc/cp/ChangeLog: > > * call.cc (add_template_conv_candidate): Don't check for > non-empty 'candidates' here. > (build_op_call): Check it here, before we've considered any > conversion functions. > > gcc/testsuite/ChangeLog: > > * g++.dg/overload/conv-op5.C: New test. > --- > gcc/cp/call.cc | 24 ++++++++++++++---------- > gcc/testsuite/g++.dg/overload/conv-op5.C | 18 ++++++++++++++++++ > 2 files changed, 32 insertions(+), 10 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/overload/conv-op5.C > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index 81935b83908..119063979fa 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -3709,12 +3709,6 @@ add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, > tree return_type, tree access_path, > tree conversion_path, tsubst_flags_t complain) > { > - /* Making this work broke PR 71117 and 85118, so until the committee resolves > - core issue 2189, let's disable this candidate if there are any call > - operators. */ > - if (*candidates) > - return NULL; > - > return > add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, > NULL_TREE, arglist, return_type, access_path, > @@ -5290,6 +5284,8 @@ build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) > LOOKUP_NORMAL, &candidates, complain); > } > > + bool any_call_ops = candidates != nullptr; > + > convs = lookup_conversions (type); > > for (; convs; convs = TREE_CHAIN (convs)) > @@ -5306,10 +5302,18 @@ build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) > continue; > > if (TREE_CODE (fn) == TEMPLATE_DECL) > - add_template_conv_candidate > - (&candidates, fn, obj, *args, totype, > - /*access_path=*/NULL_TREE, > - /*conversion_path=*/NULL_TREE, complain); > + { > + /* Making this work broke PR 71117 and 85118, so until the > + committee resolves core issue 2189, let's disable this > + candidate if there are any call operators. */ > + if (any_call_ops) > + continue; > + > + add_template_conv_candidate > + (&candidates, fn, obj, *args, totype, > + /*access_path=*/NULL_TREE, > + /*conversion_path=*/NULL_TREE, complain); > + } > else > add_conv_candidate (&candidates, fn, obj, > *args, /*conversion_path=*/NULL_TREE, > diff --git a/gcc/testsuite/g++.dg/overload/conv-op5.C b/gcc/testsuite/g++.dg/overload/conv-op5.C > new file mode 100644 > index 00000000000..b7724908b62 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/overload/conv-op5.C > @@ -0,0 +1,18 @@ > +// { dg-do compile { target c++11 } } > + > +template<class T> using F = int(*)(T); > +using G = int(*)(int*); > + > +struct A { > + template<class T> operator F<T>(); // #1 > + operator G() = delete; // #2 > +}; > + > +int i = A{}(0); // selects #1 > + > +struct B { > + operator G() = delete; // #2 > + template<class T> operator F<T>(); // #1 > +}; > + > +int j = B{}(0); // selects #1
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 81935b83908..119063979fa 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -3709,12 +3709,6 @@ add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, tree return_type, tree access_path, tree conversion_path, tsubst_flags_t complain) { - /* Making this work broke PR 71117 and 85118, so until the committee resolves - core issue 2189, let's disable this candidate if there are any call - operators. */ - if (*candidates) - return NULL; - return add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, NULL_TREE, arglist, return_type, access_path, @@ -5290,6 +5284,8 @@ build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) LOOKUP_NORMAL, &candidates, complain); } + bool any_call_ops = candidates != nullptr; + convs = lookup_conversions (type); for (; convs; convs = TREE_CHAIN (convs)) @@ -5306,10 +5302,18 @@ build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) continue; if (TREE_CODE (fn) == TEMPLATE_DECL) - add_template_conv_candidate - (&candidates, fn, obj, *args, totype, - /*access_path=*/NULL_TREE, - /*conversion_path=*/NULL_TREE, complain); + { + /* Making this work broke PR 71117 and 85118, so until the + committee resolves core issue 2189, let's disable this + candidate if there are any call operators. */ + if (any_call_ops) + continue; + + add_template_conv_candidate + (&candidates, fn, obj, *args, totype, + /*access_path=*/NULL_TREE, + /*conversion_path=*/NULL_TREE, complain); + } else add_conv_candidate (&candidates, fn, obj, *args, /*conversion_path=*/NULL_TREE, diff --git a/gcc/testsuite/g++.dg/overload/conv-op5.C b/gcc/testsuite/g++.dg/overload/conv-op5.C new file mode 100644 index 00000000000..b7724908b62 --- /dev/null +++ b/gcc/testsuite/g++.dg/overload/conv-op5.C @@ -0,0 +1,18 @@ +// { dg-do compile { target c++11 } } + +template<class T> using F = int(*)(T); +using G = int(*)(int*); + +struct A { + template<class T> operator F<T>(); // #1 + operator G() = delete; // #2 +}; + +int i = A{}(0); // selects #1 + +struct B { + operator G() = delete; // #2 + template<class T> operator F<T>(); // #1 +}; + +int j = B{}(0); // selects #1