On Fri, 5 May 2023, Patrick Palka wrote:
> Here we're neglecting to propagate parenthesized-ness when the member
> access expression (this->m) resolves to a static member (and thus
> finish_class_member_access_expr yields a VAR_DECL instead of a
> COMPONENT_REF).
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does look OK for
> trunk?
>
> PR c++/98283
>
> gcc/cp/ChangeLog:
>
> * pt.cc (tsubst_copy_and_build) <case COMPONENT_REF>: Use
> force_paren_expr on the result of finish_class_member_access_expr
> if REF_PARENTHESIZED_P.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp1y/paren6.C: New test.
> ---
> gcc/cp/pt.cc | 4 ++--
> gcc/cp/semantics.cc | 4 ++--
> gcc/testsuite/g++.dg/cpp1y/paren6.C | 14 ++++++++++++++
> 3 files changed, 18 insertions(+), 4 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp1y/paren6.C
>
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 5446b5058b7..9f5549e8f29 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -21502,8 +21502,8 @@ tsubst_copy_and_build (tree t,
> r = finish_class_member_access_expr (object, member,
> /*template_p=*/false,
> complain);
> - if (TREE_CODE (r) == COMPONENT_REF)
> - REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
> + if (REF_PARENTHESIZED_P (t))
> + r = force_paren_expr (r);
> RETURN (r);
> }
>
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 474da71bff6..c4fea2f0f0f 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -2069,8 +2069,8 @@ finish_mem_initializers (tree mem_inits)
> that the call to finish_decltype in do_auto_deduction will give the
> right result. If EVEN_UNEVAL, do this even in unevaluated context. */
>
> -tree
> -force_paren_expr (tree expr, bool even_uneval)
> +static tree
> +force_paren_expr (tree expr, bool even_uneval /* = false */)
Whoops, I managed to send the wrong amended patch (I opted to document
this default arg as a drive-by change after the fact). The correct
patch is:
-- >8 --
Subject: [PATCH] c++: parenthesized -> resolving to static data member
[PR98283]
Here we're neglecting to propagate parenthesized-ness when the
member access (this->m) resolves to a static data member (and
thus finish_class_member_access_expr yields a VAR_DECL instead
of a COMPONENT_REF).
Bootstrapped and regtested on x86_64-pc-linux-gnu, does look OK for
trunk?
PR c++/98283
gcc/cp/ChangeLog:
* pt.cc (tsubst_copy_and_build) <case COMPONENT_REF>: Use
force_paren_expr on the result of finish_class_member_access_expr
if REF_PARENTHESIZED_P.
* semantics.cc (force_paren_expr): Document default argument.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/paren6.C: New test.
---
gcc/cp/pt.cc | 4 ++--
gcc/cp/semantics.cc | 2 +-
gcc/testsuite/g++.dg/cpp1y/paren6.C | 14 ++++++++++++++
3 files changed, 17 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/paren6.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 5446b5058b7..9f5549e8f29 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -21502,8 +21502,8 @@ tsubst_copy_and_build (tree t,
r = finish_class_member_access_expr (object, member,
/*template_p=*/false,
complain);
- if (TREE_CODE (r) == COMPONENT_REF)
- REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
+ if (REF_PARENTHESIZED_P (t))
+ r = force_paren_expr (r);
RETURN (r);
}
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 474da71bff6..13c6582b628 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -2070,7 +2070,7 @@ finish_mem_initializers (tree mem_inits)
right result. If EVEN_UNEVAL, do this even in unevaluated context. */
tree
-force_paren_expr (tree expr, bool even_uneval)
+force_paren_expr (tree expr, bool even_uneval /* = false */)
{
/* This is only needed for decltype(auto) in C++14. */
if (cxx_dialect < cxx14)
diff --git a/gcc/testsuite/g++.dg/cpp1y/paren6.C
b/gcc/testsuite/g++.dg/cpp1y/paren6.C
new file mode 100644
index 00000000000..812a99ca91c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/paren6.C
@@ -0,0 +1,14 @@
+// PR c++/98283
+// { dg-do compile { target c++14 } }
+
+struct A {
+ static int m;
+};
+
+template<class T>
+struct B : T {
+ decltype(auto) f() { return (this->m); }
+};
+
+using type = decltype(B<A>().f());
+using type = int&;
--
2.40.1.476.g69c786637d
