On Thu, 19 Oct 2023, Jason Merrill wrote:
> On 10/12/23 14:49, Patrick Palka wrote:
> > On Tue, 26 Sep 2023, Patrick Palka wrote:
> >
> > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
> > > for trunk?
> > >
> > > -- >8 --
> > >
> > > This follow-up patch removes some more repetition of the type-dependent
> >
> > On second thought there's no good reason to split these patches into a two
> > part series, so here's a single squashed patch:
>
> OK.
Thanks. It turns out this patch slightly depends on the
NON_DEPENDENT_EXPR removal patches, since without them finish_call_expr
in a template context will undesirably do build_non_dependent_expr on
the fn/args before its COMPONENT_REF branch that dispatches to
build_new_method_call, but this latter function expects to be called
with unwrapped fn/args. This (seemingly latent bug) can trivially be
fixed by moving finish_call_expr's build_non_dependent_expr calls to
happen after the COMPONENT_REF branch, but I reckon I'll just wait until
the NON_DEPENDENT_EXPR removal patches are in before pushing this one.
>
> > -- >8 --
> >
> > Subject: [PATCH] c++: non-static memfn call dependence cleanup [PR106086]
> >
> > In cp_parser_postfix_expression and in the CALL_EXPR case of
> > tsubst_copy_and_build, we essentially repeat the type-dependent and
> > COMPONENT_REF callee cases of finish_call_expr. This patch deduplicates
> > this logic by making both spots consistently go through finish_call_expr.
> >
> > This allows us to easily fix PR106086 -- which is about us neglecting to
> > capture 'this' when we resolve a use of a non-static member function of
> > the current instantiation only at lambda regeneration time -- by moving
> > the call to maybe_generic_this_capture from the parser to finish_call_expr
> > so that we consider capturing 'this' at regeneration time as well.
> >
> > PR c++/106086
> >
> > gcc/cp/ChangeLog:
> >
> > * parser.cc (cp_parser_postfix_expression): Consolidate three
> > calls to finish_call_expr, one to build_new_method_call and
> > one to build_min_nt_call_vec into one call to finish_call_expr.
> > Don't call maybe_generic_this_capture here.
> > * pt.cc (tsubst_copy_and_build) <case CALL_EXPR>: Remove
> > COMPONENT_REF callee handling.
> > (type_dependent_expression_p): Use t_d_object_e_p instead of
> > t_d_e_p for COMPONENT_REF and OFFSET_REF.
> > * semantics.cc (finish_call_expr): In the type-dependent case,
> > call maybe_generic_this_capture here instead.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/template/crash127.C: Expect additional error due to
> > being able to check the member access expression ahead of time.
> > Strengthen the test by not instantiating the class template.
> > * g++.dg/cpp1y/lambda-generic-this5.C: New test.
> > ---
> > gcc/cp/parser.cc | 52 +++----------------
> > gcc/cp/pt.cc | 27 +---------
> > gcc/cp/semantics.cc | 12 +++--
> > .../g++.dg/cpp1y/lambda-generic-this5.C | 22 ++++++++
> > gcc/testsuite/g++.dg/template/crash127.C | 3 +-
> > 5 files changed, 38 insertions(+), 78 deletions(-)
> > create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-this5.C
> >
> > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> > index f3abae716fe..b00ef36b831 100644
> > --- a/gcc/cp/parser.cc
> > +++ b/gcc/cp/parser.cc
> > @@ -8047,54 +8047,12 @@ cp_parser_postfix_expression (cp_parser *parser,
> > bool address_p, bool cast_p,
> > close_paren_loc);
> > iloc_sentinel ils (combined_loc);
> > - if (TREE_CODE (postfix_expression) == COMPONENT_REF)
> > - {
> > - tree instance = TREE_OPERAND (postfix_expression, 0);
> > - tree fn = TREE_OPERAND (postfix_expression, 1);
> > -
> > - if (processing_template_decl
> > - && (type_dependent_object_expression_p (instance)
> > - || (!BASELINK_P (fn)
> > - && TREE_CODE (fn) != FIELD_DECL)
> > - || type_dependent_expression_p (fn)
> > - || any_type_dependent_arguments_p (args)))
> > - {
> > - maybe_generic_this_capture (instance, fn);
> > - postfix_expression
> > - = build_min_nt_call_vec (postfix_expression, args);
> > - }
> > - else if (BASELINK_P (fn))
> > - {
> > - postfix_expression
> > - = (build_new_method_call
> > - (instance, fn, &args, NULL_TREE,
> > - (idk == CP_ID_KIND_QUALIFIED
> > - ? LOOKUP_NORMAL|LOOKUP_NONVIRTUAL
> > - : LOOKUP_NORMAL),
> > - /*fn_p=*/NULL,
> > - complain));
> > - }
> > - else
> > - postfix_expression
> > - = finish_call_expr (postfix_expression, &args,
> > - /*disallow_virtual=*/false,
> > - /*koenig_p=*/false,
> > - complain);
> > - }
> > - else if (TREE_CODE (postfix_expression) == OFFSET_REF
> > - || TREE_CODE (postfix_expression) == MEMBER_REF
> > - || TREE_CODE (postfix_expression) == DOTSTAR_EXPR)
> > + if (TREE_CODE (postfix_expression) == OFFSET_REF
> > + || TREE_CODE (postfix_expression) == MEMBER_REF
> > + || TREE_CODE (postfix_expression) == DOTSTAR_EXPR)
> > postfix_expression = (build_offset_ref_call_from_tree
> > (postfix_expression, &args,
> > complain));
> > - else if (idk == CP_ID_KIND_QUALIFIED)
> > - /* A call to a static class member, or a namespace-scope
> > - function. */
> > - postfix_expression
> > - = finish_call_expr (postfix_expression, &args,
> > - /*disallow_virtual=*/true,
> > - koenig_p,
> > - complain);
> > else
> > /* All other function calls. */
> > {
> > @@ -8107,12 +8065,14 @@ cp_parser_postfix_expression (cp_parser *parser,
> > bool address_p, bool cast_p,
> > "not permitted in intervening code");
> > parser->omp_for_parse_state->fail = true;
> > }
> > + bool disallow_virtual = (idk == CP_ID_KIND_QUALIFIED);
> > postfix_expression
> > = finish_call_expr (postfix_expression, &args,
> > - /*disallow_virtual=*/false,
> > + disallow_virtual,
> > koenig_p,
> > complain);
> > }
> > +
> > if (close_paren_loc != UNKNOWN_LOCATION)
> > postfix_expression.set_location (combined_loc);
> > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> > index 382db4dd01d..4400d429b6f 100644
> > --- a/gcc/cp/pt.cc
> > +++ b/gcc/cp/pt.cc
> > @@ -21364,31 +21364,6 @@ tsubst_copy_and_build (tree t,
> > || TREE_CODE (function) == MEMBER_REF)
> > ret = build_offset_ref_call_from_tree (function, &call_args,
> > complain);
> > - else if (TREE_CODE (function) == COMPONENT_REF)
> > - {
> > - tree instance = TREE_OPERAND (function, 0);
> > - tree fn = TREE_OPERAND (function, 1);
> > -
> > - if (processing_template_decl
> > - && (type_dependent_expression_p (instance)
> > - || (!BASELINK_P (fn)
> > - && TREE_CODE (fn) != FIELD_DECL)
> > - || type_dependent_expression_p (fn)
> > - || any_type_dependent_arguments_p (call_args)))
> > - ret = build_min_nt_call_vec (function, call_args);
> > - else if (!BASELINK_P (fn))
> > - ret = finish_call_expr (function, &call_args,
> > - /*disallow_virtual=*/false,
> > - /*koenig_p=*/false,
> > - complain);
> > - else
> > - ret = (build_new_method_call
> > - (instance, fn,
> > - &call_args, NULL_TREE,
> > - qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
> > - /*fn_p=*/NULL,
> > - complain));
> > - }
> > else if (concept_check_p (function))
> > {
> > /* FUNCTION is a template-id referring to a concept definition.
> > */
> > @@ -28585,7 +28560,7 @@ type_dependent_expression_p (tree expression)
> > if (TREE_CODE (expression) == COMPONENT_REF
> > || TREE_CODE (expression) == OFFSET_REF)
> > {
> > - if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
> > + if (type_dependent_object_expression_p (TREE_OPERAND (expression,
> > 0)))
> > return true;
> > expression = TREE_OPERAND (expression, 1);
> > if (identifier_p (expression))
> > diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> > index 1d478f0781f..412eaa12851 100644
> > --- a/gcc/cp/semantics.cc
> > +++ b/gcc/cp/semantics.cc
> > @@ -2793,18 +2793,19 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args,
> > bool disallow_virtual,
> > (c++/89780, c++/107363). This also suppresses the
> > -Wredundant-move warning. */
> > suppress_warning (result, OPT_Wpessimizing_move);
> > - if (is_overloaded_fn (fn))
> > - fn = get_fns (fn);
> > if (cfun)
> > {
> > bool abnormal = true;
> > - for (lkp_iterator iter (fn); abnormal && iter; ++iter)
> > + for (lkp_iterator iter (maybe_get_fns (fn)); iter; ++iter)
> > {
> > tree fndecl = STRIP_TEMPLATE (*iter);
> > if (TREE_CODE (fndecl) != FUNCTION_DECL
> > || !TREE_THIS_VOLATILE (fndecl))
> > - abnormal = false;
> > + {
> > + abnormal = false;
> > + break;
> > + }
> > }
> > /* FIXME: Stop warning about falling off end of non-void
> > function. But this is wrong. Even if we only see
> > @@ -2814,6 +2815,9 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args,
> > bool disallow_virtual,
> > if (abnormal)
> > current_function_returns_abnormally = 1;
> > }
> > + if (TREE_CODE (fn) == COMPONENT_REF)
> > + maybe_generic_this_capture (TREE_OPERAND (fn, 0),
> > + TREE_OPERAND (fn, 1));
> > return result;
> > }
> > orig_args = make_tree_vector_copy (*args);
> > diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-this5.C
> > b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-this5.C
> > new file mode 100644
> > index 00000000000..42f917094d9
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-this5.C
> > @@ -0,0 +1,22 @@
> > +// PR c++/106086
> > +// { dg-do compile { target c++14 } }
> > +
> > +template<class T>
> > +struct A {
> > + void f(int) const;
> > + static void g(int);
> > +};
> > +
> > +template<class T>
> > +struct B : A<T> {
> > + auto f() const {
> > + auto l1 = [&](auto x) { A<T>::f(x); };
> > + auto l2 = [&](auto x) { A<T>::g(x); };
> > + static_assert(sizeof(l1) == sizeof(this), "");
> > + static_assert(sizeof(l2) == 1, "");
> > + l1(0);
> > + l2(0);
> > + }
> > +};
> > +
> > +template struct B<void>;
> > diff --git a/gcc/testsuite/g++.dg/template/crash127.C
> > b/gcc/testsuite/g++.dg/template/crash127.C
> > index b7c03251f8c..fcf72d871db 100644
> > --- a/gcc/testsuite/g++.dg/template/crash127.C
> > +++ b/gcc/testsuite/g++.dg/template/crash127.C
> > @@ -16,7 +16,6 @@ struct C : public A
> > {
> > B < &A::A > b; // { dg-error "taking address of constructor 'A::A" ""
> > { target c++98_only } }
> > // { dg-error "taking address of constructor 'constexpr A::A" "" {
> > target c++11 } .-1 }
> > + // { dg-error "template argument 1 is invalid" "" { target *-*-* } .-2
> > }
> > }
> > };
> > -
> > -template class C < int >;
>
>
