* [PATCH] c++: recognize in-class var tmpl partial spec [PR71954]
@ 2023-08-10 16:08 Patrick Palka
2023-08-10 21:16 ` Jason Merrill
0 siblings, 1 reply; 2+ messages in thread
From: Patrick Palka @ 2023-08-10 16:08 UTC (permalink / raw)
To: gcc-patches; +Cc: jason, Patrick Palka
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
for trunk?
-- >8 --
This makes us recognize variable template partial specializations
defined directly inside the class body. It seems to suffice to call
check_explicit_specialization when we see a static TEMPLATE_ID_EXPR data
member, which sets SET_DECL_TEMPLATE_SPECIALIZATION and which we
otherwise don't call (for out-of-class partial specializations we call
it from from grokvardecl which is used only for out-of-class definitions).
We also need to make finish_member_template_decl return NULL_TREE for
such partial specializations (matching its behavior class template
partial specializations) so that its caller doesn't try to call
finish_member_declaration on it.
PR c++/71954
gcc/cp/ChangeLog:
* decl.cc (grokdeclarator): Use 'dname' instead of
'unqualified_id' when building the VAR_DECL for a static data
member. Call check_explicit_specialization for a
TEMPLATE_ID_EXPR such member.
* pt.cc (finish_member_template_decl): Return NULL_TREE
instead of 'decl' when DECL_TEMPLATE_SPECIALIZATION is not
set.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/var-templ84.C: New test.
* g++.dg/cpp1y/var-templ84a.C: New test.
---
gcc/cp/decl.cc | 11 ++++++++++-
gcc/cp/pt.cc | 2 +-
gcc/testsuite/g++.dg/cpp1y/var-templ84.C | 12 ++++++++++++
gcc/testsuite/g++.dg/cpp1y/var-templ84a.C | 19 +++++++++++++++++++
4 files changed, 42 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ84.C
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 9fe3a0b98fd..2b3fb313166 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -14440,7 +14440,16 @@ grokdeclarator (const cp_declarator *declarator,
/* C++ allows static class members. All other work
for this is done by grokfield. */
decl = build_lang_decl_loc (id_loc, VAR_DECL,
- unqualified_id, type);
+ dname, type);
+ if (unqualified_id
+ && TREE_CODE (unqualified_id) == TEMPLATE_ID_EXPR)
+ {
+ decl = check_explicit_specialization (unqualified_id, decl,
+ template_count,
+ concept_p * 8);
+ if (decl == error_mark_node)
+ return error_mark_node;
+ }
set_linkage_for_static_data_member (decl);
if (concept_p)
error_at (declspecs->locations[ds_concept],
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 2706fa619bf..a4809f034dc 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -314,7 +314,7 @@ finish_member_template_decl (tree decl)
return DECL_TI_TEMPLATE (decl);
}
else
- return decl;
+ return NULL_TREE;
}
else
error_at (DECL_SOURCE_LOCATION (decl),
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ84.C b/gcc/testsuite/g++.dg/cpp1y/var-templ84.C
new file mode 100644
index 00000000000..39c2a0dc0cc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ84.C
@@ -0,0 +1,12 @@
+// PR c++/71954
+// { dg-do compile { target c++14 } }
+
+struct A {
+ template<class T> static const int var = 0;
+ template<class T> static const int var<T*> = 1;
+ template<class T> static const int var<const T*> = 2;
+};
+
+static_assert(A::var<int> == 0, "");
+static_assert(A::var<int*> == 1, "");
+static_assert(A::var<const int*> == 2, "");
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C b/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
new file mode 100644
index 00000000000..4aa3a2a7245
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
@@ -0,0 +1,19 @@
+// PR c++/71954
+// A version of var-templ84.C where the partial specializations depend on
+// outer template parameters.
+// { dg-do compile { target c++14 } }
+
+template<class T>
+struct A {
+ template<class U, class V> static const int var = 0;
+ template<class U> static const int var<U*, T> = 1;
+ template<class U> static const int var<const U*, T> = 2;
+};
+
+static_assert(A<int>::var<int, int> == 0, "");
+static_assert(A<int>::var<int*, int> == 1, "");
+static_assert(A<int>::var<const int*, int> == 2, "");
+
+static_assert(A<int>::var<int, char> == 0, "");
+static_assert(A<int>::var<int*, char> == 0, "");
+static_assert(A<int>::var<const int*, char> == 0, "");
--
2.42.0.rc0.25.ga82fb66fed
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] c++: recognize in-class var tmpl partial spec [PR71954]
2023-08-10 16:08 [PATCH] c++: recognize in-class var tmpl partial spec [PR71954] Patrick Palka
@ 2023-08-10 21:16 ` Jason Merrill
0 siblings, 0 replies; 2+ messages in thread
From: Jason Merrill @ 2023-08-10 21:16 UTC (permalink / raw)
To: Patrick Palka, gcc-patches
On 8/10/23 12:08, Patrick Palka wrote:
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
> for trunk?
OK.
> -- >8 --
>
> This makes us recognize variable template partial specializations
> defined directly inside the class body. It seems to suffice to call
> check_explicit_specialization when we see a static TEMPLATE_ID_EXPR data
> member, which sets SET_DECL_TEMPLATE_SPECIALIZATION and which we
> otherwise don't call (for out-of-class partial specializations we call
> it from from grokvardecl which is used only for out-of-class definitions).
> We also need to make finish_member_template_decl return NULL_TREE for
> such partial specializations (matching its behavior class template
> partial specializations) so that its caller doesn't try to call
> finish_member_declaration on it.
>
> PR c++/71954
>
> gcc/cp/ChangeLog:
>
> * decl.cc (grokdeclarator): Use 'dname' instead of
> 'unqualified_id' when building the VAR_DECL for a static data
> member. Call check_explicit_specialization for a
> TEMPLATE_ID_EXPR such member.
> * pt.cc (finish_member_template_decl): Return NULL_TREE
> instead of 'decl' when DECL_TEMPLATE_SPECIALIZATION is not
> set.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp1y/var-templ84.C: New test.
> * g++.dg/cpp1y/var-templ84a.C: New test.
> ---
> gcc/cp/decl.cc | 11 ++++++++++-
> gcc/cp/pt.cc | 2 +-
> gcc/testsuite/g++.dg/cpp1y/var-templ84.C | 12 ++++++++++++
> gcc/testsuite/g++.dg/cpp1y/var-templ84a.C | 19 +++++++++++++++++++
> 4 files changed, 42 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ84.C
> create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
>
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 9fe3a0b98fd..2b3fb313166 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -14440,7 +14440,16 @@ grokdeclarator (const cp_declarator *declarator,
> /* C++ allows static class members. All other work
> for this is done by grokfield. */
> decl = build_lang_decl_loc (id_loc, VAR_DECL,
> - unqualified_id, type);
> + dname, type);
> + if (unqualified_id
> + && TREE_CODE (unqualified_id) == TEMPLATE_ID_EXPR)
> + {
> + decl = check_explicit_specialization (unqualified_id, decl,
> + template_count,
> + concept_p * 8);
> + if (decl == error_mark_node)
> + return error_mark_node;
> + }
> set_linkage_for_static_data_member (decl);
> if (concept_p)
> error_at (declspecs->locations[ds_concept],
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 2706fa619bf..a4809f034dc 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -314,7 +314,7 @@ finish_member_template_decl (tree decl)
> return DECL_TI_TEMPLATE (decl);
> }
> else
> - return decl;
> + return NULL_TREE;
> }
> else
> error_at (DECL_SOURCE_LOCATION (decl),
> diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ84.C b/gcc/testsuite/g++.dg/cpp1y/var-templ84.C
> new file mode 100644
> index 00000000000..39c2a0dc0cc
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ84.C
> @@ -0,0 +1,12 @@
> +// PR c++/71954
> +// { dg-do compile { target c++14 } }
> +
> +struct A {
> + template<class T> static const int var = 0;
> + template<class T> static const int var<T*> = 1;
> + template<class T> static const int var<const T*> = 2;
> +};
> +
> +static_assert(A::var<int> == 0, "");
> +static_assert(A::var<int*> == 1, "");
> +static_assert(A::var<const int*> == 2, "");
> diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C b/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
> new file mode 100644
> index 00000000000..4aa3a2a7245
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ84a.C
> @@ -0,0 +1,19 @@
> +// PR c++/71954
> +// A version of var-templ84.C where the partial specializations depend on
> +// outer template parameters.
> +// { dg-do compile { target c++14 } }
> +
> +template<class T>
> +struct A {
> + template<class U, class V> static const int var = 0;
> + template<class U> static const int var<U*, T> = 1;
> + template<class U> static const int var<const U*, T> = 2;
> +};
> +
> +static_assert(A<int>::var<int, int> == 0, "");
> +static_assert(A<int>::var<int*, int> == 1, "");
> +static_assert(A<int>::var<const int*, int> == 2, "");
> +
> +static_assert(A<int>::var<int, char> == 0, "");
> +static_assert(A<int>::var<int*, char> == 0, "");
> +static_assert(A<int>::var<const int*, char> == 0, "");
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