* [PATCH] c++: non-dependent immediate member fn call [PR99895] @ 2022-01-19 16:15 Patrick Palka 2022-01-19 19:19 ` Jason Merrill 0 siblings, 1 reply; 6+ messages in thread From: Patrick Palka @ 2022-01-19 16:15 UTC (permalink / raw) To: gcc-patches Here we're emitting a bogus error during ahead of time evaluation of a non-dependent immediate member function call such as a.f(args) because the defacto templated form for such a call is (a.f)(args) but we're trying to evaluate it using the intermediate CALL_EXPR built by build_over_call, which has the non-member form f(a, args). The defacto member form is built in build_new_method_call, so it seems we should handle the immediate call there instead. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps 11? PR c++/99895 gcc/cp/ChangeLog: * call.cc (build_over_call): Don't evaluate non-dependent immediate member function calls here. (build_new_method_call): Instead evaluate them here. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/consteval-memfn1.C: New test. * g++.dg/cpp2a/consteval-memfn2.C: New test. --- gcc/cp/call.cc | 9 ++++- gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 15 ++++++++ gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++++ 3 files changed, 57 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index d4a07a7a9b3..0583cc0083b 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -9241,7 +9241,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) addr, nargs, argarray); if (TREE_THIS_VOLATILE (fn) && cfun) current_function_returns_abnormally = 1; - if (immediate_invocation_p (fn, nargs)) + if (!DECL_FUNCTION_MEMBER_P (fn) + /* Non-dependent immediate member function calls are evaluated in + build_new_method_call. */ + && immediate_invocation_p (fn, nargs)) { tree obj_arg = NULL_TREE, exprimm = expr; if (DECL_CONSTRUCTOR_P (fn)) @@ -11227,6 +11230,10 @@ skip_prune: call = convert_from_reference (call); if (cast_to_void) call = build_nop (void_type_node, call); + + if (immediate_invocation_p (fn, vec_safe_length (orig_args))) + fold_non_dependent_expr (call, complain, + /*manifestly_const_eval=*/true); } /* Free all the conversions we allocated. */ diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C new file mode 100644 index 00000000000..d2df2e9b5ae --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C @@ -0,0 +1,15 @@ +// PR c++/99895 +// { dg-do compile { target c++20 } } + +struct fixed_string { + consteval int size(int n) const { + if (n < 0) throw; // { dg-error "not a constant" } + return n; + } +}; + +template<class> +void VerifyHash(fixed_string s) { + s.size(0); // { dg-bogus "" } + s.size(-1); // { dg-message "expansion of" } +} diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C new file mode 100644 index 00000000000..71748f46b13 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C @@ -0,0 +1,34 @@ +// PR c++/99895 +// { dg-do compile { target c++20 } } + +static constexpr unsigned hash(const char* s, unsigned length) +{ + s=s; + return length; +} +template<unsigned N> +struct fixed_string +{ + constexpr fixed_string(const char (&s)[N]) + { + for (int i = 0; i < N; i++) + str[i] = s[i]; + } + consteval const char* data() const { return str; } + consteval unsigned size() const { return N-1; } + char str[N]; +}; +template<unsigned expected_hash, fixed_string... s> +static consteval void VerifyHash() +{ + ( + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) + ,...); + // The compiler mistakenly translates s.data() into s.data(&s) + // and then complains that the call is not valid, because + // the function expects 0 parameters and 1 "was provided". +} +void foo() +{ + VerifyHash<5, "khaki", "plums">(); +} -- 2.35.0.rc1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] c++: non-dependent immediate member fn call [PR99895] 2022-01-19 16:15 [PATCH] c++: non-dependent immediate member fn call [PR99895] Patrick Palka @ 2022-01-19 19:19 ` Jason Merrill 2022-01-26 22:27 ` Patrick Palka 0 siblings, 1 reply; 6+ messages in thread From: Jason Merrill @ 2022-01-19 19:19 UTC (permalink / raw) To: Patrick Palka, gcc-patches On 1/19/22 11:15, Patrick Palka wrote: > Here we're emitting a bogus error during ahead of time evaluation of a > non-dependent immediate member function call such as a.f(args) because > the defacto templated form for such a call is (a.f)(args) but we're > trying to evaluate it using the intermediate CALL_EXPR built by > build_over_call, which has the non-member form f(a, args). The defacto > member form is built in build_new_method_call, so it seems we should > handle the immediate call there instead. Hmm, there's already a bunch of code in build_over_call to try to fix up the object argument, and there seem to be many places other than build_new_method_call that call build_over_call for member functions; I think it's probably better to build the needed COMPONENT_REF in build_over_call. > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk and perhaps 11? > > PR c++/99895 > > gcc/cp/ChangeLog: > > * call.cc (build_over_call): Don't evaluate non-dependent > immediate member function calls here. > (build_new_method_call): Instead evaluate them here. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/consteval-memfn1.C: New test. > * g++.dg/cpp2a/consteval-memfn2.C: New test. > --- > gcc/cp/call.cc | 9 ++++- > gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 15 ++++++++ > gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++++ > 3 files changed, 57 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index d4a07a7a9b3..0583cc0083b 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -9241,7 +9241,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > addr, nargs, argarray); > if (TREE_THIS_VOLATILE (fn) && cfun) > current_function_returns_abnormally = 1; > - if (immediate_invocation_p (fn, nargs)) > + if (!DECL_FUNCTION_MEMBER_P (fn) > + /* Non-dependent immediate member function calls are evaluated in > + build_new_method_call. */ > + && immediate_invocation_p (fn, nargs)) > { > tree obj_arg = NULL_TREE, exprimm = expr; > if (DECL_CONSTRUCTOR_P (fn)) > @@ -11227,6 +11230,10 @@ skip_prune: > call = convert_from_reference (call); > if (cast_to_void) > call = build_nop (void_type_node, call); > + > + if (immediate_invocation_p (fn, vec_safe_length (orig_args))) > + fold_non_dependent_expr (call, complain, > + /*manifestly_const_eval=*/true); > } > > /* Free all the conversions we allocated. */ > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > new file mode 100644 > index 00000000000..d2df2e9b5ae > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > @@ -0,0 +1,15 @@ > +// PR c++/99895 > +// { dg-do compile { target c++20 } } > + > +struct fixed_string { > + consteval int size(int n) const { > + if (n < 0) throw; // { dg-error "not a constant" } > + return n; > + } > +}; > + > +template<class> > +void VerifyHash(fixed_string s) { > + s.size(0); // { dg-bogus "" } > + s.size(-1); // { dg-message "expansion of" } > +} > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > new file mode 100644 > index 00000000000..71748f46b13 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > @@ -0,0 +1,34 @@ > +// PR c++/99895 > +// { dg-do compile { target c++20 } } > + > +static constexpr unsigned hash(const char* s, unsigned length) > +{ > + s=s; > + return length; > +} > +template<unsigned N> > +struct fixed_string > +{ > + constexpr fixed_string(const char (&s)[N]) > + { > + for (int i = 0; i < N; i++) > + str[i] = s[i]; > + } > + consteval const char* data() const { return str; } > + consteval unsigned size() const { return N-1; } > + char str[N]; > +}; > +template<unsigned expected_hash, fixed_string... s> > +static consteval void VerifyHash() > +{ > + ( > + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) > + ,...); > + // The compiler mistakenly translates s.data() into s.data(&s) > + // and then complains that the call is not valid, because > + // the function expects 0 parameters and 1 "was provided". > +} > +void foo() > +{ > + VerifyHash<5, "khaki", "plums">(); > +} ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] c++: non-dependent immediate member fn call [PR99895] 2022-01-19 19:19 ` Jason Merrill @ 2022-01-26 22:27 ` Patrick Palka 2022-01-26 22:46 ` Patrick Palka 0 siblings, 1 reply; 6+ messages in thread From: Patrick Palka @ 2022-01-26 22:27 UTC (permalink / raw) To: Jason Merrill; +Cc: GCC Patches On Wed, Jan 19, 2022 at 2:19 PM Jason Merrill <jason@redhat.com> wrote: > > On 1/19/22 11:15, Patrick Palka wrote: > > Here we're emitting a bogus error during ahead of time evaluation of a > > non-dependent immediate member function call such as a.f(args) because > > the defacto templated form for such a call is (a.f)(args) but we're > > trying to evaluate it using the intermediate CALL_EXPR built by > > build_over_call, which has the non-member form f(a, args). The defacto > > member form is built in build_new_method_call, so it seems we should > > handle the immediate call there instead. > > Hmm, there's already a bunch of code in build_over_call to try to fix up > the object argument, and there seem to be many places other than > build_new_method_call that call build_over_call for member functions; I > think it's probably better to build the needed COMPONENT_REF in > build_over_call. Ah, but in build_over_call the arguments (including the implicit object argument) are potentially wrapped in a NON_DEPENDENT_EXPR. So even if we built a COMPONENT_REF in build_over_call, we'd have to keep rebuilding the entire CALL_EXPR (including the COMPONENT_REF) in terms of the original arguments in build_new_method_call, IIUC. On a related note, the NON_DEPENDENT_EXPR wrapping seems to be a problem for non-member functions too, because the constexpr engine punts on them: struct fixed_string { }; static consteval void size(fixed_string) { } template<class> void VerifyHash(fixed_string s) { size(s); // error: expression ‘s’ is not a constant expression (because it's wrapped in NON_DEPENDENT_EXPR) } I wonder if this means we should be evaluating non-dependent non-member immediate calls elsewhere, e.g. in finish_call_expr? Or perhaps we should stop punting on NON_DEPENDENT_EXPR during constexpr evaluation? > > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > > trunk and perhaps 11? > > > > PR c++/99895 > > > > gcc/cp/ChangeLog: > > > > * call.cc (build_over_call): Don't evaluate non-dependent > > immediate member function calls here. > > (build_new_method_call): Instead evaluate them here. > > > > gcc/testsuite/ChangeLog: > > > > * g++.dg/cpp2a/consteval-memfn1.C: New test. > > * g++.dg/cpp2a/consteval-memfn2.C: New test. > > --- > > gcc/cp/call.cc | 9 ++++- > > gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 15 ++++++++ > > gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++++ > > 3 files changed, 57 insertions(+), 1 deletion(-) > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > > index d4a07a7a9b3..0583cc0083b 100644 > > --- a/gcc/cp/call.cc > > +++ b/gcc/cp/call.cc > > @@ -9241,7 +9241,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > > addr, nargs, argarray); > > if (TREE_THIS_VOLATILE (fn) && cfun) > > current_function_returns_abnormally = 1; > > - if (immediate_invocation_p (fn, nargs)) > > + if (!DECL_FUNCTION_MEMBER_P (fn) > > + /* Non-dependent immediate member function calls are evaluated in > > + build_new_method_call. */ > > + && immediate_invocation_p (fn, nargs)) > > { > > tree obj_arg = NULL_TREE, exprimm = expr; > > if (DECL_CONSTRUCTOR_P (fn)) > > @@ -11227,6 +11230,10 @@ skip_prune: > > call = convert_from_reference (call); > > if (cast_to_void) > > call = build_nop (void_type_node, call); > > + > > + if (immediate_invocation_p (fn, vec_safe_length (orig_args))) > > + fold_non_dependent_expr (call, complain, > > + /*manifestly_const_eval=*/true); > > } > > > > /* Free all the conversions we allocated. */ > > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > new file mode 100644 > > index 00000000000..d2df2e9b5ae > > --- /dev/null > > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > @@ -0,0 +1,15 @@ > > +// PR c++/99895 > > +// { dg-do compile { target c++20 } } > > + > > +struct fixed_string { > > + consteval int size(int n) const { > > + if (n < 0) throw; // { dg-error "not a constant" } > > + return n; > > + } > > +}; > > + > > +template<class> > > +void VerifyHash(fixed_string s) { > > + s.size(0); // { dg-bogus "" } > > + s.size(-1); // { dg-message "expansion of" } > > +} > > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > new file mode 100644 > > index 00000000000..71748f46b13 > > --- /dev/null > > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > @@ -0,0 +1,34 @@ > > +// PR c++/99895 > > +// { dg-do compile { target c++20 } } > > + > > +static constexpr unsigned hash(const char* s, unsigned length) > > +{ > > + s=s; > > + return length; > > +} > > +template<unsigned N> > > +struct fixed_string > > +{ > > + constexpr fixed_string(const char (&s)[N]) > > + { > > + for (int i = 0; i < N; i++) > > + str[i] = s[i]; > > + } > > + consteval const char* data() const { return str; } > > + consteval unsigned size() const { return N-1; } > > + char str[N]; > > +}; > > +template<unsigned expected_hash, fixed_string... s> > > +static consteval void VerifyHash() > > +{ > > + ( > > + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) > > + ,...); > > + // The compiler mistakenly translates s.data() into s.data(&s) > > + // and then complains that the call is not valid, because > > + // the function expects 0 parameters and 1 "was provided". > > +} > > +void foo() > > +{ > > + VerifyHash<5, "khaki", "plums">(); > > +} > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] c++: non-dependent immediate member fn call [PR99895] 2022-01-26 22:27 ` Patrick Palka @ 2022-01-26 22:46 ` Patrick Palka 2022-01-27 14:02 ` Patrick Palka 0 siblings, 1 reply; 6+ messages in thread From: Patrick Palka @ 2022-01-26 22:46 UTC (permalink / raw) To: Patrick Palka; +Cc: Jason Merrill, GCC Patches On Wed, 26 Jan 2022, Patrick Palka wrote: > On Wed, Jan 19, 2022 at 2:19 PM Jason Merrill <jason@redhat.com> wrote: > > > > On 1/19/22 11:15, Patrick Palka wrote: > > > Here we're emitting a bogus error during ahead of time evaluation of a > > > non-dependent immediate member function call such as a.f(args) because > > > the defacto templated form for such a call is (a.f)(args) but we're > > > trying to evaluate it using the intermediate CALL_EXPR built by > > > build_over_call, which has the non-member form f(a, args). The defacto > > > member form is built in build_new_method_call, so it seems we should > > > handle the immediate call there instead. > > > > Hmm, there's already a bunch of code in build_over_call to try to fix up > > the object argument, and there seem to be many places other than > > build_new_method_call that call build_over_call for member functions; I > > think it's probably better to build the needed COMPONENT_REF in > > build_over_call. > > Ah, but in build_over_call the arguments (including the implicit > object argument) are potentially wrapped in a NON_DEPENDENT_EXPR. So > even if we built a COMPONENT_REF in build_over_call, we'd have to > keep rebuilding the entire CALL_EXPR (including the COMPONENT_REF) in > terms of the original arguments in build_new_method_call, IIUC. > > On a related note, the NON_DEPENDENT_EXPR wrapping seems to be a > problem for non-member functions too, because the constexpr engine > punts on them: > > struct fixed_string { }; > > static consteval void size(fixed_string) { } > > template<class> > void VerifyHash(fixed_string s) { > size(s); // error: expression ‘s’ is not a constant expression > (because it's wrapped in NON_DEPENDENT_EXPR) > } > > I wonder if this means we should be evaluating non-dependent > non-member immediate calls elsewhere, e.g. in finish_call_expr? Or > perhaps we should stop punting on NON_DEPENDENT_EXPR during constexpr > evaluation? Actually, for that particular example, we probably should just avoid wrapping PARM_DECL in a NON_DEPENDENT_EXPR... > > > > > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > > > trunk and perhaps 11? > > > > > > PR c++/99895 > > > > > > gcc/cp/ChangeLog: > > > > > > * call.cc (build_over_call): Don't evaluate non-dependent > > > immediate member function calls here. > > > (build_new_method_call): Instead evaluate them here. > > > > > > gcc/testsuite/ChangeLog: > > > > > > * g++.dg/cpp2a/consteval-memfn1.C: New test. > > > * g++.dg/cpp2a/consteval-memfn2.C: New test. > > > --- > > > gcc/cp/call.cc | 9 ++++- > > > gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 15 ++++++++ > > > gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++++ > > > 3 files changed, 57 insertions(+), 1 deletion(-) > > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > > > > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > > > index d4a07a7a9b3..0583cc0083b 100644 > > > --- a/gcc/cp/call.cc > > > +++ b/gcc/cp/call.cc > > > @@ -9241,7 +9241,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > > > addr, nargs, argarray); > > > if (TREE_THIS_VOLATILE (fn) && cfun) > > > current_function_returns_abnormally = 1; > > > - if (immediate_invocation_p (fn, nargs)) > > > + if (!DECL_FUNCTION_MEMBER_P (fn) > > > + /* Non-dependent immediate member function calls are evaluated in > > > + build_new_method_call. */ > > > + && immediate_invocation_p (fn, nargs)) > > > { > > > tree obj_arg = NULL_TREE, exprimm = expr; > > > if (DECL_CONSTRUCTOR_P (fn)) > > > @@ -11227,6 +11230,10 @@ skip_prune: > > > call = convert_from_reference (call); > > > if (cast_to_void) > > > call = build_nop (void_type_node, call); > > > + > > > + if (immediate_invocation_p (fn, vec_safe_length (orig_args))) > > > + fold_non_dependent_expr (call, complain, > > > + /*manifestly_const_eval=*/true); > > > } > > > > > > /* Free all the conversions we allocated. */ > > > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > > new file mode 100644 > > > index 00000000000..d2df2e9b5ae > > > --- /dev/null > > > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > > > @@ -0,0 +1,15 @@ > > > +// PR c++/99895 > > > +// { dg-do compile { target c++20 } } > > > + > > > +struct fixed_string { > > > + consteval int size(int n) const { > > > + if (n < 0) throw; // { dg-error "not a constant" } > > > + return n; > > > + } > > > +}; > > > + > > > +template<class> > > > +void VerifyHash(fixed_string s) { > > > + s.size(0); // { dg-bogus "" } > > > + s.size(-1); // { dg-message "expansion of" } > > > +} > > > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > > new file mode 100644 > > > index 00000000000..71748f46b13 > > > --- /dev/null > > > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > > > @@ -0,0 +1,34 @@ > > > +// PR c++/99895 > > > +// { dg-do compile { target c++20 } } > > > + > > > +static constexpr unsigned hash(const char* s, unsigned length) > > > +{ > > > + s=s; > > > + return length; > > > +} > > > +template<unsigned N> > > > +struct fixed_string > > > +{ > > > + constexpr fixed_string(const char (&s)[N]) > > > + { > > > + for (int i = 0; i < N; i++) > > > + str[i] = s[i]; > > > + } > > > + consteval const char* data() const { return str; } > > > + consteval unsigned size() const { return N-1; } > > > + char str[N]; > > > +}; > > > +template<unsigned expected_hash, fixed_string... s> > > > +static consteval void VerifyHash() > > > +{ > > > + ( > > > + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) > > > + ,...); > > > + // The compiler mistakenly translates s.data() into s.data(&s) > > > + // and then complains that the call is not valid, because > > > + // the function expects 0 parameters and 1 "was provided". > > > +} > > > +void foo() > > > +{ > > > + VerifyHash<5, "khaki", "plums">(); > > > +} > > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] c++: non-dependent immediate member fn call [PR99895] 2022-01-26 22:46 ` Patrick Palka @ 2022-01-27 14:02 ` Patrick Palka 2022-01-27 15:31 ` Jason Merrill 0 siblings, 1 reply; 6+ messages in thread From: Patrick Palka @ 2022-01-27 14:02 UTC (permalink / raw) To: Patrick Palka; +Cc: Jason Merrill, GCC Patches On Wed, 26 Jan 2022, Patrick Palka wrote: > On Wed, 26 Jan 2022, Patrick Palka wrote: > > > On Wed, Jan 19, 2022 at 2:19 PM Jason Merrill <jason@redhat.com> wrote: > > > > > > On 1/19/22 11:15, Patrick Palka wrote: > > > > Here we're emitting a bogus error during ahead of time evaluation of a > > > > non-dependent immediate member function call such as a.f(args) because > > > > the defacto templated form for such a call is (a.f)(args) but we're > > > > trying to evaluate it using the intermediate CALL_EXPR built by > > > > build_over_call, which has the non-member form f(a, args). The defacto > > > > member form is built in build_new_method_call, so it seems we should > > > > handle the immediate call there instead. > > > > > > Hmm, there's already a bunch of code in build_over_call to try to fix up > > > the object argument, and there seem to be many places other than > > > build_new_method_call that call build_over_call for member functions; I > > > think it's probably better to build the needed COMPONENT_REF in > > > build_over_call. > > > > Ah, but in build_over_call the arguments (including the implicit > > object argument) are potentially wrapped in a NON_DEPENDENT_EXPR. So > > even if we built a COMPONENT_REF in build_over_call, we'd have to > > keep rebuilding the entire CALL_EXPR (including the COMPONENT_REF) in > > terms of the original arguments in build_new_method_call, IIUC. > > > > On a related note, the NON_DEPENDENT_EXPR wrapping seems to be a > > problem for non-member functions too, because the constexpr engine > > punts on them: > > > > struct fixed_string { }; > > > > static consteval void size(fixed_string) { } > > > > template<class> > > void VerifyHash(fixed_string s) { > > size(s); // error: expression ‘s’ is not a constant expression > > (because it's wrapped in NON_DEPENDENT_EXPR) > > } > > > > I wonder if this means we should be evaluating non-dependent > > non-member immediate calls elsewhere, e.g. in finish_call_expr? Or > > perhaps we should stop punting on NON_DEPENDENT_EXPR during constexpr > > evaluation? > > Actually, for that particular example, we probably should just avoid > wrapping PARM_DECL in a NON_DEPENDENT_EXPR... Here's a patch that makes build_over_call build the COMPONENT_REF-using form for non-dependent member calls, and in passing makes us avoid wrapping PARM_DECL in a NON_DEPENDENT_EXPR. -- >8 -- Subject: [PATCH] c++: non-dependent immediate member fn call [PR99895] Here we're emitting a bogus error during ahead of time evaluation of a non-dependent immediate member function call such as a.f(args) because the defacto templated form for such a call is (a.f)(args) but we're trying to evaluate it using the intermediate CALL_EXPR built by build_over_call, which has the non-member form f(a, args). The defacto member form is built in build_new_method_call, so it seems we should handle the immediate call there instead, or perhaps make build_over_call build the correct form in the first place. Giiven that there are many spots other than build_new_method_call that call build_over_call for member functions, this patch takes the latter approach. In passing, this patch makes us avoid wrapping PARM_DECL in NON_DEPENDENT_EXPR for benefit of the third testcase below. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? PR c++/99895 gcc/cp/ChangeLog: * call.cc (build_over_call): For a non-dependent member call, build up a CALL_EXPR using a COMPONENT_REF callee, as in build_new_method_call. * pt.cc (build_non_dependent_expr): Don't wrap PARM_DECL either. * tree.cc (build_min_non_dep_op_overload): Adjust accordingly after the build_over_call change. gcc/ChangeLog: * tree.cc (build_call_vec): Add const to second parameter. * tree.h (build_call_vec): Likewise. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/consteval-memfn1.C: New test. * g++.dg/cpp2a/consteval-memfn2.C: New test. * g++.dg/cpp2a/consteval28.C: New test. --- gcc/cp/call.cc | 38 +++++++------------ gcc/cp/pt.cc | 6 ++- gcc/cp/tree.cc | 5 ++- gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 27 +++++++++++++ gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++ gcc/testsuite/g++.dg/cpp2a/consteval28.C | 10 +++++ gcc/tree.cc | 2 +- gcc/tree.h | 2 +- 8 files changed, 94 insertions(+), 30 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval28.C diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index bc157cdd1fb..b2e89c5d783 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -9204,11 +9204,6 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) errors will be deferred until the template is instantiated. */ if (processing_template_decl) { - tree expr, addr; - tree return_type; - const tree *argarray; - unsigned int nargs; - if (undeduced_auto_decl (fn)) mark_used (fn, complain); else @@ -9216,32 +9211,27 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) See PR80598. */ TREE_USED (fn) = 1; - return_type = TREE_TYPE (TREE_TYPE (fn)); - nargs = vec_safe_length (args); + tree return_type = TREE_TYPE (TREE_TYPE (fn)); + tree callee; if (first_arg == NULL_TREE) - argarray = args->address (); + { + callee = build_addr_func (fn, complain); + if (callee == error_mark_node) + return error_mark_node; + } else { - tree *alcarray; - unsigned int ix; - tree arg; - - ++nargs; - alcarray = XALLOCAVEC (tree, nargs); - alcarray[0] = build_this (first_arg); - FOR_EACH_VEC_SAFE_ELT (args, ix, arg) - alcarray[ix + 1] = arg; - argarray = alcarray; + tree binfo = TYPE_BINFO (TREE_TYPE (first_arg)); + callee = build_baselink (binfo, binfo, fn, NULL_TREE); + callee = build_min (COMPONENT_REF, TREE_TYPE (fn), + first_arg, callee, NULL_TREE); } - addr = build_addr_func (fn, complain); - if (addr == error_mark_node) - return error_mark_node; - expr = build_call_array_loc (input_location, return_type, - addr, nargs, argarray); + tree expr = build_call_vec (return_type, callee, args); + SET_EXPR_LOCATION (expr, input_location); if (TREE_THIS_VOLATILE (fn) && cfun) current_function_returns_abnormally = 1; - if (immediate_invocation_p (fn, nargs)) + if (immediate_invocation_p (fn, vec_safe_length (args))) { tree obj_arg = NULL_TREE, exprimm = expr; if (DECL_CONSTRUCTOR_P (fn)) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 6fbda676527..19e73b3b77d 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -28410,8 +28410,10 @@ build_non_dependent_expr (tree expr) if (is_overloaded_fn (inner_expr) || TREE_CODE (inner_expr) == OFFSET_REF) return orig_expr; - /* There is no need to return a proxy for a variable or enumerator. */ - if (VAR_P (expr) || TREE_CODE (expr) == CONST_DECL) + /* There is no need to return a proxy for a variable, parameter + or enumerator. */ + if (VAR_P (expr) || TREE_CODE (expr) == PARM_DECL + || TREE_CODE (expr) == CONST_DECL) return orig_expr; /* Preserve string constants; conversions from string constants to "char *" are allowed, even though normally a "const char *" diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index 5d453e49717..056f10f13b4 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -3661,6 +3661,8 @@ build_min_non_dep_op_overload (enum tree_code op, nargs = call_expr_nargs (non_dep); expected_nargs = cp_tree_code_length (op); + if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE) + expected_nargs -= 1; if ((op == POSTINCREMENT_EXPR || op == POSTDECREMENT_EXPR) /* With -fpermissive non_dep could be operator++(). */ @@ -3687,7 +3689,7 @@ build_min_non_dep_op_overload (enum tree_code op, tree method = build_baselink (binfo, binfo, overload, NULL_TREE); fn = build_min (COMPONENT_REF, TREE_TYPE (overload), object, method, NULL_TREE); - for (int i = 1; i < nargs; i++) + for (int i = 0; i < nargs; i++) { tree arg = va_arg (p, tree); vec_safe_push (args, arg); @@ -3723,7 +3725,6 @@ build_min_non_dep_op_overload (tree non_dep, tree overload, tree object, tree method = build_baselink (binfo, binfo, overload, NULL_TREE); tree fn = build_min (COMPONENT_REF, TREE_TYPE (overload), object, method, NULL_TREE); - nargs--; gcc_assert (vec_safe_length (args) == nargs); tree call = build_min_non_dep_call_vec (non_dep, fn, args); diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C new file mode 100644 index 00000000000..910e7a1ac1e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C @@ -0,0 +1,27 @@ +// PR c++/99895 +// { dg-do compile { target c++20 } } + +struct fixed_string { + consteval int size(int n) const { + if (n < 0) throw; // { dg-error "not a constant" } + return n; + } + + static consteval int size_static(int n) { + if (n < 0) throw; // { dg-error "not a constant" } + return n; + } + + consteval void operator()() const { } +}; + +template<class> +void VerifyHash(fixed_string s) { + s.size(0); // { dg-bogus "" } + s.size(-1); // { dg-message "expansion of" } + s.size_static(0); // { dg-bogus "" } + s.size_static(-1); // { dg-message "expansion of" } + fixed_string::size_static(0); // { dg-bogus "" } + fixed_string::size_static(-1); // { dg-message "expansion of" } + s(); // { dg-bogus "" } +} diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C new file mode 100644 index 00000000000..71748f46b13 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C @@ -0,0 +1,34 @@ +// PR c++/99895 +// { dg-do compile { target c++20 } } + +static constexpr unsigned hash(const char* s, unsigned length) +{ + s=s; + return length; +} +template<unsigned N> +struct fixed_string +{ + constexpr fixed_string(const char (&s)[N]) + { + for (int i = 0; i < N; i++) + str[i] = s[i]; + } + consteval const char* data() const { return str; } + consteval unsigned size() const { return N-1; } + char str[N]; +}; +template<unsigned expected_hash, fixed_string... s> +static consteval void VerifyHash() +{ + ( + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) + ,...); + // The compiler mistakenly translates s.data() into s.data(&s) + // and then complains that the call is not valid, because + // the function expects 0 parameters and 1 "was provided". +} +void foo() +{ + VerifyHash<5, "khaki", "plums">(); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval28.C b/gcc/testsuite/g++.dg/cpp2a/consteval28.C new file mode 100644 index 00000000000..293a6be2fc5 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval28.C @@ -0,0 +1,10 @@ +// { dg-do compile { target c++20 } } + +struct empty { }; + +consteval void f(empty) { } + +template<class> +void g(empty e) { + f(e); +} diff --git a/gcc/tree.cc b/gcc/tree.cc index c4b36619e6a..9d445b2740f 100644 --- a/gcc/tree.cc +++ b/gcc/tree.cc @@ -10492,7 +10492,7 @@ build_call_array_loc (location_t loc, tree return_type, tree fn, /* Like build_call_array, but takes a vec. */ tree -build_call_vec (tree return_type, tree fn, vec<tree, va_gc> *args) +build_call_vec (tree return_type, tree fn, const vec<tree, va_gc> *args) { tree ret, t; unsigned int ix; diff --git a/gcc/tree.h b/gcc/tree.h index 30bc53c2996..4c01d94244e 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -4589,7 +4589,7 @@ extern tree build_call_valist (tree, tree, int, va_list); #define build_call_array(T1,T2,N,T3)\ build_call_array_loc (UNKNOWN_LOCATION, T1, T2, N, T3) extern tree build_call_array_loc (location_t, tree, tree, int, const tree *); -extern tree build_call_vec (tree, tree, vec<tree, va_gc> *); +extern tree build_call_vec (tree, tree, const vec<tree, va_gc> *); extern tree build_call_expr_loc_array (location_t, tree, int, tree *); extern tree build_call_expr_loc_vec (location_t, tree, vec<tree, va_gc> *); extern tree build_call_expr_loc (location_t, tree, int, ...); -- 2.35.0 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] c++: non-dependent immediate member fn call [PR99895] 2022-01-27 14:02 ` Patrick Palka @ 2022-01-27 15:31 ` Jason Merrill 0 siblings, 0 replies; 6+ messages in thread From: Jason Merrill @ 2022-01-27 15:31 UTC (permalink / raw) To: Patrick Palka; +Cc: GCC Patches On 1/27/22 09:02, Patrick Palka wrote: > On Wed, 26 Jan 2022, Patrick Palka wrote: > >> On Wed, 26 Jan 2022, Patrick Palka wrote: >> >>> On Wed, Jan 19, 2022 at 2:19 PM Jason Merrill <jason@redhat.com> wrote: >>>> >>>> On 1/19/22 11:15, Patrick Palka wrote: >>>>> Here we're emitting a bogus error during ahead of time evaluation of a >>>>> non-dependent immediate member function call such as a.f(args) because >>>>> the defacto templated form for such a call is (a.f)(args) but we're >>>>> trying to evaluate it using the intermediate CALL_EXPR built by >>>>> build_over_call, which has the non-member form f(a, args). The defacto >>>>> member form is built in build_new_method_call, so it seems we should >>>>> handle the immediate call there instead. >>>> >>>> Hmm, there's already a bunch of code in build_over_call to try to fix up >>>> the object argument, and there seem to be many places other than >>>> build_new_method_call that call build_over_call for member functions; I >>>> think it's probably better to build the needed COMPONENT_REF in >>>> build_over_call. >>> >>> Ah, but in build_over_call the arguments (including the implicit >>> object argument) are potentially wrapped in a NON_DEPENDENT_EXPR. So >>> even if we built a COMPONENT_REF in build_over_call, we'd have to >>> keep rebuilding the entire CALL_EXPR (including the COMPONENT_REF) in >>> terms of the original arguments in build_new_method_call, IIUC. >>> >>> On a related note, the NON_DEPENDENT_EXPR wrapping seems to be a >>> problem for non-member functions too, because the constexpr engine >>> punts on them: >>> >>> struct fixed_string { }; >>> >>> static consteval void size(fixed_string) { } >>> >>> template<class> >>> void VerifyHash(fixed_string s) { >>> size(s); // error: expression ‘s’ is not a constant expression >>> (because it's wrapped in NON_DEPENDENT_EXPR) >>> } >>> >>> I wonder if this means we should be evaluating non-dependent >>> non-member immediate calls elsewhere, e.g. in finish_call_expr? Or >>> perhaps we should stop punting on NON_DEPENDENT_EXPR during constexpr >>> evaluation? >> >> Actually, for that particular example, we probably should just avoid >> wrapping PARM_DECL in a NON_DEPENDENT_EXPR... > > Here's a patch that makes build_over_call build the COMPONENT_REF-using > form for non-dependent member calls, and in passing makes us avoid > wrapping PARM_DECL in a NON_DEPENDENT_EXPR. > > -- >8 -- > > Subject: [PATCH] c++: non-dependent immediate member fn call [PR99895] > > Here we're emitting a bogus error during ahead of time evaluation of a > non-dependent immediate member function call such as a.f(args) because > the defacto templated form for such a call is (a.f)(args) but we're > trying to evaluate it using the intermediate CALL_EXPR built by > build_over_call, which has the non-member form f(a, args). The defacto > member form is built in build_new_method_call, so it seems we should > handle the immediate call there instead, or perhaps make build_over_call > build the correct form in the first place. > > Giiven that there are many spots other than build_new_method_call that > call build_over_call for member functions, this patch takes the latter > approach. > > In passing, this patch makes us avoid wrapping PARM_DECL in > NON_DEPENDENT_EXPR for benefit of the third testcase below. > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk? OK. > PR c++/99895 > > gcc/cp/ChangeLog: > > * call.cc (build_over_call): For a non-dependent member call, > build up a CALL_EXPR using a COMPONENT_REF callee, as in > build_new_method_call. > * pt.cc (build_non_dependent_expr): Don't wrap PARM_DECL either. > * tree.cc (build_min_non_dep_op_overload): Adjust accordingly > after the build_over_call change. > > gcc/ChangeLog: > > * tree.cc (build_call_vec): Add const to second parameter. > * tree.h (build_call_vec): Likewise. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/consteval-memfn1.C: New test. > * g++.dg/cpp2a/consteval-memfn2.C: New test. > * g++.dg/cpp2a/consteval28.C: New test. > --- > gcc/cp/call.cc | 38 +++++++------------ > gcc/cp/pt.cc | 6 ++- > gcc/cp/tree.cc | 5 ++- > gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 27 +++++++++++++ > gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C | 34 +++++++++++++++++ > gcc/testsuite/g++.dg/cpp2a/consteval28.C | 10 +++++ > gcc/tree.cc | 2 +- > gcc/tree.h | 2 +- > 8 files changed, 94 insertions(+), 30 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval28.C > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index bc157cdd1fb..b2e89c5d783 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -9204,11 +9204,6 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > errors will be deferred until the template is instantiated. */ > if (processing_template_decl) > { > - tree expr, addr; > - tree return_type; > - const tree *argarray; > - unsigned int nargs; > - > if (undeduced_auto_decl (fn)) > mark_used (fn, complain); > else > @@ -9216,32 +9211,27 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > See PR80598. */ > TREE_USED (fn) = 1; > > - return_type = TREE_TYPE (TREE_TYPE (fn)); > - nargs = vec_safe_length (args); > + tree return_type = TREE_TYPE (TREE_TYPE (fn)); > + tree callee; > if (first_arg == NULL_TREE) > - argarray = args->address (); > + { > + callee = build_addr_func (fn, complain); > + if (callee == error_mark_node) > + return error_mark_node; > + } > else > { > - tree *alcarray; > - unsigned int ix; > - tree arg; > - > - ++nargs; > - alcarray = XALLOCAVEC (tree, nargs); > - alcarray[0] = build_this (first_arg); > - FOR_EACH_VEC_SAFE_ELT (args, ix, arg) > - alcarray[ix + 1] = arg; > - argarray = alcarray; > + tree binfo = TYPE_BINFO (TREE_TYPE (first_arg)); > + callee = build_baselink (binfo, binfo, fn, NULL_TREE); > + callee = build_min (COMPONENT_REF, TREE_TYPE (fn), > + first_arg, callee, NULL_TREE); > } > > - addr = build_addr_func (fn, complain); > - if (addr == error_mark_node) > - return error_mark_node; > - expr = build_call_array_loc (input_location, return_type, > - addr, nargs, argarray); > + tree expr = build_call_vec (return_type, callee, args); > + SET_EXPR_LOCATION (expr, input_location); > if (TREE_THIS_VOLATILE (fn) && cfun) > current_function_returns_abnormally = 1; > - if (immediate_invocation_p (fn, nargs)) > + if (immediate_invocation_p (fn, vec_safe_length (args))) > { > tree obj_arg = NULL_TREE, exprimm = expr; > if (DECL_CONSTRUCTOR_P (fn)) > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > index 6fbda676527..19e73b3b77d 100644 > --- a/gcc/cp/pt.cc > +++ b/gcc/cp/pt.cc > @@ -28410,8 +28410,10 @@ build_non_dependent_expr (tree expr) > if (is_overloaded_fn (inner_expr) > || TREE_CODE (inner_expr) == OFFSET_REF) > return orig_expr; > - /* There is no need to return a proxy for a variable or enumerator. */ > - if (VAR_P (expr) || TREE_CODE (expr) == CONST_DECL) > + /* There is no need to return a proxy for a variable, parameter > + or enumerator. */ > + if (VAR_P (expr) || TREE_CODE (expr) == PARM_DECL > + || TREE_CODE (expr) == CONST_DECL) > return orig_expr; > /* Preserve string constants; conversions from string constants to > "char *" are allowed, even though normally a "const char *" > diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc > index 5d453e49717..056f10f13b4 100644 > --- a/gcc/cp/tree.cc > +++ b/gcc/cp/tree.cc > @@ -3661,6 +3661,8 @@ build_min_non_dep_op_overload (enum tree_code op, > nargs = call_expr_nargs (non_dep); > > expected_nargs = cp_tree_code_length (op); > + if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE) > + expected_nargs -= 1; > if ((op == POSTINCREMENT_EXPR > || op == POSTDECREMENT_EXPR) > /* With -fpermissive non_dep could be operator++(). */ > @@ -3687,7 +3689,7 @@ build_min_non_dep_op_overload (enum tree_code op, > tree method = build_baselink (binfo, binfo, overload, NULL_TREE); > fn = build_min (COMPONENT_REF, TREE_TYPE (overload), > object, method, NULL_TREE); > - for (int i = 1; i < nargs; i++) > + for (int i = 0; i < nargs; i++) > { > tree arg = va_arg (p, tree); > vec_safe_push (args, arg); > @@ -3723,7 +3725,6 @@ build_min_non_dep_op_overload (tree non_dep, tree overload, tree object, > tree method = build_baselink (binfo, binfo, overload, NULL_TREE); > tree fn = build_min (COMPONENT_REF, TREE_TYPE (overload), > object, method, NULL_TREE); > - nargs--; > gcc_assert (vec_safe_length (args) == nargs); > > tree call = build_min_non_dep_call_vec (non_dep, fn, args); > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > new file mode 100644 > index 00000000000..910e7a1ac1e > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C > @@ -0,0 +1,27 @@ > +// PR c++/99895 > +// { dg-do compile { target c++20 } } > + > +struct fixed_string { > + consteval int size(int n) const { > + if (n < 0) throw; // { dg-error "not a constant" } > + return n; > + } > + > + static consteval int size_static(int n) { > + if (n < 0) throw; // { dg-error "not a constant" } > + return n; > + } > + > + consteval void operator()() const { } > +}; > + > +template<class> > +void VerifyHash(fixed_string s) { > + s.size(0); // { dg-bogus "" } > + s.size(-1); // { dg-message "expansion of" } > + s.size_static(0); // { dg-bogus "" } > + s.size_static(-1); // { dg-message "expansion of" } > + fixed_string::size_static(0); // { dg-bogus "" } > + fixed_string::size_static(-1); // { dg-message "expansion of" } > + s(); // { dg-bogus "" } > +} > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > new file mode 100644 > index 00000000000..71748f46b13 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn2.C > @@ -0,0 +1,34 @@ > +// PR c++/99895 > +// { dg-do compile { target c++20 } } > + > +static constexpr unsigned hash(const char* s, unsigned length) > +{ > + s=s; > + return length; > +} > +template<unsigned N> > +struct fixed_string > +{ > + constexpr fixed_string(const char (&s)[N]) > + { > + for (int i = 0; i < N; i++) > + str[i] = s[i]; > + } > + consteval const char* data() const { return str; } > + consteval unsigned size() const { return N-1; } > + char str[N]; > +}; > +template<unsigned expected_hash, fixed_string... s> > +static consteval void VerifyHash() > +{ > + ( > + [](auto){static_assert(hash(s.data(), s.size()) == expected_hash);}(s) > + ,...); > + // The compiler mistakenly translates s.data() into s.data(&s) > + // and then complains that the call is not valid, because > + // the function expects 0 parameters and 1 "was provided". > +} > +void foo() > +{ > + VerifyHash<5, "khaki", "plums">(); > +} > diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval28.C b/gcc/testsuite/g++.dg/cpp2a/consteval28.C > new file mode 100644 > index 00000000000..293a6be2fc5 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/consteval28.C > @@ -0,0 +1,10 @@ > +// { dg-do compile { target c++20 } } > + > +struct empty { }; > + > +consteval void f(empty) { } > + > +template<class> > +void g(empty e) { > + f(e); > +} > diff --git a/gcc/tree.cc b/gcc/tree.cc > index c4b36619e6a..9d445b2740f 100644 > --- a/gcc/tree.cc > +++ b/gcc/tree.cc > @@ -10492,7 +10492,7 @@ build_call_array_loc (location_t loc, tree return_type, tree fn, > /* Like build_call_array, but takes a vec. */ > > tree > -build_call_vec (tree return_type, tree fn, vec<tree, va_gc> *args) > +build_call_vec (tree return_type, tree fn, const vec<tree, va_gc> *args) > { > tree ret, t; > unsigned int ix; > diff --git a/gcc/tree.h b/gcc/tree.h > index 30bc53c2996..4c01d94244e 100644 > --- a/gcc/tree.h > +++ b/gcc/tree.h > @@ -4589,7 +4589,7 @@ extern tree build_call_valist (tree, tree, int, va_list); > #define build_call_array(T1,T2,N,T3)\ > build_call_array_loc (UNKNOWN_LOCATION, T1, T2, N, T3) > extern tree build_call_array_loc (location_t, tree, tree, int, const tree *); > -extern tree build_call_vec (tree, tree, vec<tree, va_gc> *); > +extern tree build_call_vec (tree, tree, const vec<tree, va_gc> *); > extern tree build_call_expr_loc_array (location_t, tree, int, tree *); > extern tree build_call_expr_loc_vec (location_t, tree, vec<tree, va_gc> *); > extern tree build_call_expr_loc (location_t, tree, int, ...); ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-01-27 15:31 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-01-19 16:15 [PATCH] c++: non-dependent immediate member fn call [PR99895] Patrick Palka 2022-01-19 19:19 ` Jason Merrill 2022-01-26 22:27 ` Patrick Palka 2022-01-26 22:46 ` Patrick Palka 2022-01-27 14:02 ` Patrick Palka 2022-01-27 15:31 ` Jason Merrill
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).