From: Patrick Palka <ppalka@redhat.com>
To: Jason Merrill <jason@redhat.com>
Cc: Patrick Palka <ppalka@redhat.com>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] c++: decltype of by-ref capture proxy of ref [PR115504]
Date: Tue, 25 Jun 2024 11:45:32 -0400 (EDT) [thread overview]
Message-ID: <1c41d032-e545-c299-964f-b6ff58673820@idea> (raw)
In-Reply-To: <135ed513-7642-476e-9e7c-1ba916ed3cc7@redhat.com>
On Tue, 25 Jun 2024, Jason Merrill wrote:
> On 6/25/24 11:03, Patrick Palka wrote:
> > On Mon, 24 Jun 2024, Jason Merrill wrote:
> >
> > > On 6/24/24 21:00, Patrick Palka wrote:
> > > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
> > > > for trunk/14?
> > > >
> > > > -- >8 --
> > > >
> > > > The capture proxy handling in finish_decltype_type added in r14-5330
> > > > was stripping the reference type of a capture proxy's captured variable,
> > > > which is desirable for a by-value capture, but not for a by-ref capture
> > > > (of a reference).
> > >
> > > I'm not sure why we would want it for by-value, either; regardless of the
> > > capture kind, decltype(x) is int&.
> >
> > Ah, makes sense. But I guess that means
> >
> > void f(int& x) {
> > [x]() {
> > decltype(auto) a = x;
> > }
> > }
> >
> > is ill-formed since decltype(x) is int& but the corresponding closure
> > member is const? It works if we make the lambda mutable.
>
> Yes, and clang agrees. Let's also test that case.
Like so?
-- >8 --
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
Subject: [PATCH] c++: decltype of capture proxy of ref [PR115504]
The capture proxy handling in finish_decltype_type added in r14-5330
was stripping the reference type of a capture proxy's captured variable.
PR c++/115504
gcc/cp/ChangeLog:
* semantics.cc (finish_decltype_type): Don't strip the reference
type (if any) of a capture proxy's captured variable.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/decltype-auto8.C: New test.
---
gcc/cp/semantics.cc | 1 -
gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C | 22 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 6c1813d37c6..6a383c0f7f9 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12071,7 +12071,6 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
{
expr = DECL_CAPTURED_VARIABLE (expr);
type = TREE_TYPE (expr);
- type = non_reference (type);
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
new file mode 100644
index 00000000000..55135cecf72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto8.C
@@ -0,0 +1,22 @@
+// PR c++/115504
+// { dg-do compile { target c++14 } }
+
+void f(int& x, const int& y) {
+ [&x]() {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&; // not 'int'
+ };
+
+ [x]() {
+ decltype(auto) a = x; // { dg-error "discards qualifiers" }
+ };
+
+ [x]() mutable {
+ decltype(auto) a = x;
+ using type = decltype(x);
+ using type = decltype(a);
+ using type = int&;
+ };
+}
--
2.45.2.648.g1e1586e4ed
next prev parent reply other threads:[~2024-06-25 15:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-25 1:00 Patrick Palka
2024-06-25 1:48 ` Jason Merrill
2024-06-25 15:03 ` Patrick Palka
2024-06-25 15:31 ` Jason Merrill
2024-06-25 15:45 ` Patrick Palka [this message]
2024-06-25 21:24 ` Jason Merrill
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