On 5/10/23 14:11, Patrick Palka wrote:
On Wed, 10 May 2023, Jason Merrill wrote:
On 5/10/23 11:36, Patrick Palka wrote:
r8-1253-g3d2e25a240c711 removed the template argument linkage requirement
in convert_nontype_argument for C++17, but we need to also remove the one
in convert_nontype_argument_function for sake of the first and third test
case which we incorrectly reject (in C++17/20 mode).
And in invalid_tparm_referent_p we're inadvertendly rejecting using the
address of a lambda's static op() due to the DECL_ARTIFICIAL check.
This patch relaxes this check for sake of the second test case which we
incorrectly reject (in C++20 mode).
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk and perhaps 13 (since it's a relatively easy/safe fix for a
popular non-regression bug).
Co-authored-by: Jonathan Wakely <jwak...@redhat.com>
PR c++/83258
PR c++/80488
PR c++/97700
gcc/cp/ChangeLog:
* pt.cc (convert_nontype_argument_function): Disable linkage
requirement for C++17 and later.
(invalid_tparm_referent_p): Relax DECL_ARTIFICIAL check for
the artificial static op() of a lambda.
gcc/testsuite/ChangeLog:
* g++.dg/ext/visibility/anon8.C: Don't expect a "no linkage"
error for the template argument &B2:fn in C++17 mode.
* g++.dg/cpp0x/lambda/lambda-conv15.C: New test.
* g++.dg/cpp2a/nontype-class56.C: New test.
* g++.dg/template/function2.C: New test.
---
gcc/cp/pt.cc | 7 +++++--
gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C | 11 +++++++++++
gcc/testsuite/g++.dg/cpp2a/nontype-class56.C | 8 ++++++++
gcc/testsuite/g++.dg/ext/visibility/anon8.C | 4 ++--
gcc/testsuite/g++.dg/template/function2.C | 8 ++++++++
5 files changed, 34 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class56.C
create mode 100644 gcc/testsuite/g++.dg/template/function2.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 696df2bdd9f..c9b089f8fa7 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -6782,7 +6782,8 @@ convert_nontype_argument_function (tree type, tree
expr,
}
linkage = decl_linkage (fn_no_ptr);
- if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external)
+ if ((cxx_dialect < cxx11 && linkage != lk_external)
+ || (cxx_dialect < cxx17 && linkage == lk_none))
{
if (complain & tf_error)
{
@@ -7180,7 +7181,9 @@ invalid_tparm_referent_p (tree type, tree expr,
tsubst_flags_t complain)
* a string literal (5.13.5),
* the result of a typeid expression (8.2.8), or
* a predefined __func__ variable (11.4.1). */
- else if (DECL_ARTIFICIAL (decl))
+ else if (DECL_ARTIFICIAL (decl)
+ /* Accept the artificial static op() of a lambda. */
+ && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (decl)))
Maybe check for FUNCTION_DECL instead? I think the cases we want to diagnose
are all VAR_DECL.
Makes sense, before r13-6970-gb5e38b1c166357 this code path would only
be reachable for VAR_DECL anyway. Like so? Bootstrapped and regtested
on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps 13?
OK for both.
-- >8 --
Subject: [PATCH] c++: converted lambda as template argument [PR83258, ...]
r8-1253-g3d2e25a240c711 removed the template argument linkage requirement
in convert_nontype_argument for C++17, but we need to also remove the one
in convert_nontype_argument_function for sake of the first and third test
case which we incorrectly reject (in C++17/20 mode).
And in invalid_tparm_referent_p we're inadvertendly diagnosing using the
address of a lambda's static op() since it's DECL_ARTIFICIAL, which causes
us to reject the second (C++20) testcase. But this DECL_ARTIFICIAL check
seems to be relevant only for VAR_DECL, and indeed code path was reached
only for VAR_DECL until r13-6970-gb5e38b1c166357. So this patch relaxes
the check accordingly.
Co-authored-by: Jonathan Wakely <jwak...@redhat.com>
PR c++/83258
PR c++/80488
PR c++/97700
gcc/cp/ChangeLog:
* pt.cc (convert_nontype_argument_function): Disable linkage
check for C++17 and later.
(invalid_tparm_referent_p): Accept DECL_ARTIFICIAL FUNCTION_DECL.
gcc/testsuite/ChangeLog:
* g++.dg/ext/visibility/anon8.C: Don't expect a "no linkage"
error for the template argument &B2:fn in C++17 mode.
* g++.dg/cpp0x/lambda/lambda-conv15.C: New test.
* g++.dg/cpp2a/nontype-class56.C: New test.
* g++.dg/template/function2.C: New test.
---
gcc/cp/pt.cc | 5 +++--
gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C | 11 +++++++++++
gcc/testsuite/g++.dg/cpp2a/nontype-class56.C | 8 ++++++++
gcc/testsuite/g++.dg/ext/visibility/anon8.C | 4 ++--
gcc/testsuite/g++.dg/template/function2.C | 8 ++++++++
5 files changed, 32 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class56.C
create mode 100644 gcc/testsuite/g++.dg/template/function2.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 696df2bdd9f..351fc18b600 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -6782,7 +6782,8 @@ convert_nontype_argument_function (tree type, tree expr,
}
linkage = decl_linkage (fn_no_ptr);
- if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external)
+ if ((cxx_dialect < cxx11 && linkage != lk_external)
+ || (cxx_dialect < cxx17 && linkage == lk_none))
{
if (complain & tf_error)
{
@@ -7180,7 +7181,7 @@ invalid_tparm_referent_p (tree type, tree expr,
tsubst_flags_t complain)
* a string literal (5.13.5),
* the result of a typeid expression (8.2.8), or
* a predefined __func__ variable (11.4.1). */
- else if (DECL_ARTIFICIAL (decl))
+ else if (VAR_P (decl) && DECL_ARTIFICIAL (decl))
{
if (complain & tf_error)
error ("the address of %qD is not a valid template argument",
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C
b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C
new file mode 100644
index 00000000000..cf45e06a33d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C
@@ -0,0 +1,11 @@
+// PR c++/83258
+// PR c++/80488
+// { dg-do compile { target c++11 } }
+
+template<void(*)()> struct A { };
+
+int main() {
+ constexpr auto fp = +[]{}; // { dg-error "non-'constexpr' function" "" {
target c++14_down } }
+ A<fp> a1; // { dg-error "not a valid template argument" "" { target
c++14_down } }
+ A<[]{}> a2; // { dg-error "lambda-expression in template-argument|invalid"
"" { target c++17_down } }
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C
b/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C
new file mode 100644
index 00000000000..0efd735c8a3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C
@@ -0,0 +1,8 @@
+// PR c++/97700
+// { dg-do compile { target c++20 } }
+
+struct S { void (*f)(); };
+
+template<S> struct X { };
+
+X<S{[]{}}> x;
diff --git a/gcc/testsuite/g++.dg/ext/visibility/anon8.C
b/gcc/testsuite/g++.dg/ext/visibility/anon8.C
index b8507497d32..bfcc2d06df6 100644
--- a/gcc/testsuite/g++.dg/ext/visibility/anon8.C
+++ b/gcc/testsuite/g++.dg/ext/visibility/anon8.C
@@ -2,7 +2,7 @@
// { dg-do compile }
template <void (*fn) ()>
-void call () // { dg-message "note" }
+void call () // { dg-message "note" "" { target c++14_down }
}
{
fn ();
}
@@ -26,7 +26,7 @@ int main ()
static void fn2 () {}
};
call<&B1::fn1> ();
- call<&B2::fn2> (); // { dg-error "linkage|no matching" }
+ call<&B2::fn2> (); // { dg-error "linkage|no matching" "" { target
c++14_down } }
call<&fn3> ();
call<&B1::fn4> ();
call<&fn5> (); // { dg-error "linkage|no matching" "" { target { ! c++11
} } }
diff --git a/gcc/testsuite/g++.dg/template/function2.C
b/gcc/testsuite/g++.dg/template/function2.C
new file mode 100644
index 00000000000..54c48e6b36f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/function2.C
@@ -0,0 +1,8 @@
+// PR c++/83258
+
+template<void(*)()> struct A { };
+
+int main() {
+ struct B { static void f() { } };
+ A<B::f> a; // { dg-error "linkage" "" { target c++14_down } }
+}
