Tested on x86_64-pc-linux-gnu, OK for trunk if full bootstrap+regtest
passes?
-- >8 --
For the sake of determining if there are other errors in user code to
report early, many trait functions don't return error_mark_node if not
called in a SFINAE context (i.e., tf_error is set). This patch removes
some assumptions on this behaviour I'd made when improving diagnostics
of builtin traits.
PR c++/121291
gcc/cp/ChangeLog:
* constraint.cc (diagnose_trait_expr): Remove assumption about
failures returning error_mark_node.
* method.cc (build_invoke): Adjust comment.
(is_nothrow_convertible): Check for errorcount changes.
gcc/testsuite/ChangeLog:
* g++.dg/ext/is_invocable7.C: New test.
* g++.dg/ext/is_nothrow_convertible5.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
---
gcc/cp/constraint.cc | 9 +++++---
gcc/cp/method.cc | 9 ++++++--
gcc/testsuite/g++.dg/ext/is_invocable7.C | 21 +++++++++++++++++++
.../g++.dg/ext/is_nothrow_convertible5.C | 15 +++++++++++++
4 files changed, 49 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/is_invocable7.C
create mode 100644 gcc/testsuite/g++.dg/ext/is_nothrow_convertible5.C
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index d4a83e429e5..94238c9e8f1 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3176,8 +3176,7 @@ diagnose_trait_expr (location_t loc, tree expr, tree args)
inform (loc, "%qT is not invocable, because", t1);
else
inform (loc, "%qT is not invocable by %qT, because", t1, t2);
- tree call = build_invoke (t1, t2, tf_error);
- gcc_assert (call == error_mark_node);
+ build_invoke (t1, t2, tf_error);
}
break;
case CPTK_IS_LAYOUT_COMPATIBLE:
@@ -3221,8 +3220,12 @@ diagnose_trait_expr (location_t loc, tree expr, tree
args)
inform (loc, "%qT is not nothrow invocable, because", t1);
else
inform (loc, "%qT is not nothrow invocable by %qT, because", t1, t2);
+ /* We can't rely on build_invoke returning error_mark_node, because
+ when passing tf_error in some cases a valid call may be returned
+ anyway. */
+ int errs = errorcount + sorrycount;
tree call = build_invoke (t1, t2, tf_error);
- if (call != error_mark_node)
+ if (call != error_mark_node && errs == errorcount + sorrycount)
explain_not_noexcept (call);
}
break;
diff --git a/gcc/cp/method.cc b/gcc/cp/method.cc
index 62f8d80c781..cb2ea8db18d 100644
--- a/gcc/cp/method.cc
+++ b/gcc/cp/method.cc
@@ -1952,7 +1952,8 @@ build_trait_object (tree type, tsubst_flags_t complain)
}
/* [func.require] Build an expression of INVOKE(FN_TYPE, ARG_TYPES...). If the
- given is not invocable, returns error_mark_node. */
+ given is not invocable, returns error_mark_node, unless COMPLAIN includes
+ tf_error. */
tree
build_invoke (tree fn_type, const_tree arg_types, tsubst_flags_t complain)
@@ -2598,11 +2599,15 @@ is_convertible (tree from, tree to, bool
explain/*=false*/)
bool
is_nothrow_convertible (tree from, tree to, bool explain/*=false*/)
{
+ /* as with is_nothrow_xible. */
+ int errs = errorcount + sorrycount;
+
tree expr = is_convertible_helper (from, to, explain);
if (expr == NULL_TREE || expr == error_mark_node)
return false;
+
bool is_noexcept = expr_noexcept_p (expr, tf_none);
- if (explain)
+ if (explain && errs == (errorcount + sorrycount))
{
gcc_assert (!is_noexcept);
explain_not_noexcept (expr);
diff --git a/gcc/testsuite/g++.dg/ext/is_invocable7.C
b/gcc/testsuite/g++.dg/ext/is_invocable7.C
new file mode 100644
index 00000000000..5c852fc8428
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_invocable7.C
@@ -0,0 +1,21 @@
+// PR c++/121291
+// { dg-do compile { target c++17 } }
+
+template <typename T>
+constexpr bool is_invocable = __is_invocable(T);
+
+template <typename T>
+constexpr bool is_nothrow_invocable = __is_nothrow_invocable(T);
+
+struct S {
+private:
+ int operator()() noexcept; // { dg-message "here" }
+};
+
+static_assert(is_invocable<S>); // { dg-error "assert" }
+// { dg-message "not invocable" "" { target *-*-* } .-1 }
+// { dg-error "private within this context" "" { target *-*-* } .-2 }
+
+static_assert(is_nothrow_invocable<S>); // { dg-error "assert" }
+// { dg-message "not nothrow invocable" "" { target *-*-* } .-1 }
+// { dg-error "private within this context" "" { target *-*-* } .-2 }
diff --git a/gcc/testsuite/g++.dg/ext/is_nothrow_convertible5.C
b/gcc/testsuite/g++.dg/ext/is_nothrow_convertible5.C
new file mode 100644
index 00000000000..0ce8fb82191
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_nothrow_convertible5.C
@@ -0,0 +1,15 @@
+// PR c++/121291
+// { dg-do compile { target c++17 } }
+
+template <typename T, typename U>
+constexpr bool is_nothrow_convertible = __is_nothrow_convertible(T, U);
+
+struct A {};
+struct B {
+private:
+ operator A() noexcept; // { dg-message "here" }
+};
+
+static_assert(is_nothrow_convertible<B, A>); // { dg-error "assert" }
+// { dg-message "not nothrow convertible" "" { target *-*-* } .-1 }
+// { dg-error "private within this context" "" { target *-*-* } .-2 }
--
2.47.0
