Re: [PATCH] c++: recognize in-class var tmpl partial spec [PR71954]
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 000..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 static const int var = 0; + template static const int var = 1; + template static const int var = 2; +}; + +static_assert(A::var == 0, ""); +static_assert(A::var == 1, ""); +static_assert(A::var == 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 000..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 +struct A { + template static const int var = 0; + template static const int var = 1; + template static const int var = 2; +}; + +static_assert(A::var == 0, ""); +static_assert(A::var == 1, ""); +static_assert(A::var == 2, ""); + +static_assert(A::var == 0, ""); +static_assert(A::var == 0, ""); +static_assert(A::var == 0, "");
[PATCH] c++: recognize in-class var tmpl partial spec [PR71954]
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 000..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 static const int var = 0; + template static const int var = 1; + template static const int var = 2; +}; + +static_assert(A::var == 0, ""); +static_assert(A::var == 1, ""); +static_assert(A::var == 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 000..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 +struct A { + template static const int var = 0; + template static const int var = 1; + template static const int var = 2; +}; + +static_assert(A::var == 0, ""); +static_assert(A::var == 1, ""); +static_assert(A::var == 2, ""); + +static_assert(A::var == 0, ""); +static_assert(A::var == 0, ""); +static_assert(A::var == 0, ""); -- 2.42.0.rc0.25.ga82fb66fed