From 864fed4a491606a7b17325d847e1d723d2a44104 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Mon, 18 May 2020 23:50:14 -0400 Subject: [PATCH] c++: Explain fn template argument type/value mismatches [PR66439] In fn_type_unifcation, we are passing NULL_TREE as the 'in_decl' parameter to coerce_template_parms, and this is causing template type/value mismatch error messages to get suppressed regardless of the value of 'complain'. This means that when substitution into a function template fails due to a type/value mismatch between a template parameter and the provided template argument, we just say "template argument deduction/substitution failed:" without a followup explanation of the failure. Fix this by passing 'fn' instead of NULL_TREE to coerce_template_parms. gcc/cp/ChangeLog: PR c++/66439 * pt.c (fn_type_unification): Pass 'fn' instead of NULL_TREE as the 'in_decl' parameter to coerce_template_parms. gcc/testsuite/ChangeLog: PR c++/66439 * g++.dg/cpp2a/concepts-ts4.C: Expect a "type/value mismatch" diagnostic. * g++.dg/cpp2a/concepts-ts6.C: Likewise. * g++.dg/template/error56.C: Likewise. * g++.dg/template/error59.C: New test. libstdc++-v3/ChangeLog: PR c++/66439 * testsuite/20_util/pair/astuple/get_neg.cc: Prune "type/value mismatch" messages. * testsuite/20_util/tuple/element_access/get_neg.cc: Likewise. --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/pt.c | 2 +- gcc/testsuite/ChangeLog | 9 +++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C | 2 ++ gcc/testsuite/g++.dg/cpp2a/concepts-ts6.C | 4 +++- gcc/testsuite/g++.dg/template/error56.C | 2 ++ gcc/testsuite/g++.dg/template/error59.C | 11 +++++++++++ libstdc++-v3/ChangeLog | 7 +++++++ .../testsuite/20_util/pair/astuple/get_neg.cc | 1 + .../testsuite/20_util/tuple/element_access/get_neg.cc | 1 + 10 files changed, 43 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/template/error59.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 4e446585aa4..cd81891201d 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-05-19 Patrick Palka + + PR c++/66439 + * pt.c (fn_type_unification): Pass 'fn' instead of NULL_TREE as + the 'in_decl' parameter to coerce_template_parms. + 2020-05-18 Marek Polacek PR c++/94955 diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index cad5b217f3c..50933cbc23b 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -20989,7 +20989,7 @@ fn_type_unification (tree fn, /* Adjust any explicit template arguments before entering the substitution context. */ explicit_targs - = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, + = (coerce_template_parms (tparms, explicit_targs, fn, complain|tf_partial, /*require_all_args=*/false, /*use_default_args=*/false)); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 02de8028552..b0315b0207b 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2020-05-19 Patrick Palka + + PR c++/66439 + * g++.dg/cpp2a/concepts-ts4.C: Expect a "type/value mismatch" + diagnostic. + * g++.dg/cpp2a/concepts-ts6.C: Likewise. + * g++.dg/template/error56.C: Likewise. + * g++.dg/template/error59.C: New test. + 2020-05-18 Marek Polacek PR c++/94955 diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C index 23ed929acf4..cc49ff4fb27 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C @@ -31,4 +31,6 @@ void driver() fn<0>(); // OK fn<-1>(); // { dg-error "" } fn(); // { dg-error "no matching function" } + // { dg-error "type/value mismatch at argument 1" "" { target *-*-* } .-1 } + // { dg-message "expected a constant of type .int., got .int." "" { target *-*-* } .-2 } } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ts6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ts6.C index 597ad5e1ae1..8aede575f75 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-ts6.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ts6.C @@ -25,6 +25,8 @@ void driver1() { f(); f(); // { dg-error "no matching function for call" } + // { dg-error "type/value mismatch at argument 1" "" { target *-*-* } .-1 } + // { dg-message "expected a class template, got .int." "" { target *-*-* } .-2 } S2 s2a; S2 s2b; @@ -69,4 +71,4 @@ void driver2() S6 s6a; S6 s6c; // { dg-error "template constraint failure" } S6 s6b; // { dg-error "wrong number of template arguments" } -} \ No newline at end of file +} diff --git a/gcc/testsuite/g++.dg/template/error56.C b/gcc/testsuite/g++.dg/template/error56.C index 3eda04c3225..e85471a50b0 100644 --- a/gcc/testsuite/g++.dg/template/error56.C +++ b/gcc/testsuite/g++.dg/template/error56.C @@ -9,4 +9,6 @@ struct A int main() { A().f<1>(); // { dg-error "f<1>" } + // { dg-error "type/value mismatch at argument 1" "" { target *-*-* } .-1 } + // { dg-message "expected a type, got .1." "" { target *-*-* } .-2 } } diff --git a/gcc/testsuite/g++.dg/template/error59.C b/gcc/testsuite/g++.dg/template/error59.C new file mode 100644 index 00000000000..f81a28c2f1a --- /dev/null +++ b/gcc/testsuite/g++.dg/template/error59.C @@ -0,0 +1,11 @@ +template struct S { }; + +template class TT> +void foo(); + +void bar() +{ + foo(); // { dg-error "no matching function" } + // { dg-error "type/value mismatch at argument 1" "" { target *-*-* } .-1 } + // { dg-message "expected a template of type .template class TT., got .template struct S." "" { target *-*-* } .-2 } +} diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index dde62ad4779..ae1ec87589c 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,10 @@ +2020-05-19 Patrick Palka + + PR c++/66439 + * testsuite/20_util/pair/astuple/get_neg.cc: Prune "type/value + mismatch" messages. + * testsuite/20_util/tuple/element_access/get_neg.cc: Likewise. + 2020-05-15 H.J. Lu PR bootstrap/95147 diff --git a/libstdc++-v3/testsuite/20_util/pair/astuple/get_neg.cc b/libstdc++-v3/testsuite/20_util/pair/astuple/get_neg.cc index bcf3940e16d..1f76aef6d73 100644 --- a/libstdc++-v3/testsuite/20_util/pair/astuple/get_neg.cc +++ b/libstdc++-v3/testsuite/20_util/pair/astuple/get_neg.cc @@ -27,3 +27,4 @@ void test01() } // { dg-prune-output "tuple_element<2" } +// { dg-prune-output "type/value mismatch" } diff --git a/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc b/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc index 8488e287a98..03ad77215d2 100644 --- a/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc +++ b/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc @@ -61,3 +61,4 @@ test03() } // { dg-prune-output "no type named .type" } +// { dg-prune-output "type/value mismatch" } -- 2.30.2