| Message ID | 66ff55f1.170a0220.dff27.11d6@mx.google.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: Allow references to internal-linkage vars in C++11 [PR113266] | expand |
On 10/3/24 10:41 PM, Nathaniel Shead wrote: > Tested on x86_64-pc-linux-gnu, so far just dg.exp with > GXX_TESTSUITE_STDS=98,11,14,17,20,23,26,impcx. > > OK for trunk if full bootstrap + regtest passes? > > -- >8 -- > > [temp.arg.nontype] changed in C++11 to allow naming internal-linkage > variables and functions. We currently already handle internal-linkage > functions, but variables were missed; this patch updates this. > > PR c++/113266 > PR c++/116911 > > gcc/cp/ChangeLog: > > * parser.cc (cp_parser_template_argument): Allow > internal-linkage variables since C++11. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp0x/nontype6.C: New test. > > Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com> > --- > gcc/cp/parser.cc | 17 ++++++++++++----- > gcc/testsuite/g++.dg/cpp0x/nontype6.C | 19 +++++++++++++++++++ > 2 files changed, 31 insertions(+), 5 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/nontype6.C > > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc > index 08f9c89f1f0..e758ddeb1d5 100644 > --- a/gcc/cp/parser.cc > +++ b/gcc/cp/parser.cc > @@ -19864,9 +19864,11 @@ cp_parser_template_argument (cp_parser* parser) > > -- the name of a non-type template-parameter; or > > - -- the name of an object or function with external linkage... > + -- the name of an object or function with external (or internal, > + since C++11) linkage... > > - -- the address of an object or function with external linkage... > + -- the address of an object or function with external (or internal, > + since C++11) linkage... > > -- a pointer to member... */ > /* Look for a non-type template parameter. */ > @@ -19929,11 +19931,16 @@ cp_parser_template_argument (cp_parser* parser) > probe = TREE_OPERAND (probe, 1); > if (VAR_P (probe)) > { > - /* A variable without external linkage might still be a > + /* A variable without valid linkage might still be a > valid constant-expression, so no error is issued here > if the external-linkage check fails. */ > - if (!address_p && !DECL_EXTERNAL_LINKAGE_P (probe)) > - cp_parser_simulate_error (parser); > + if (!address_p && cxx_dialect < cxx17) I think you can't get here for cxx17+ because we skipped over this code with goto general_expr. OK without the cxx_dialect check. > + { > + linkage_kind linkage = decl_linkage (probe); > + if (linkage != lk_external > + && (cxx_dialect < cxx11 || linkage != lk_internal)) > + cp_parser_simulate_error (parser); > + } > } > else if (is_overloaded_fn (argument)) > /* All overloaded functions are allowed; if the external > diff --git a/gcc/testsuite/g++.dg/cpp0x/nontype6.C b/gcc/testsuite/g++.dg/cpp0x/nontype6.C > new file mode 100644 > index 00000000000..5543d1e8b6d > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/nontype6.C > @@ -0,0 +1,19 @@ > +// PR c++/113266, PR c++/116911 > +// { dg-do compile } > + > +template <int &> struct a {}; > +static int guard1; > +a<guard1> b; // { dg-error "constant-expression|invalid" "" { target c++98_only } } > + > +namespace { > + int guard2; > +} > +a<guard2> c; // OK in C++98 because guard2 has external linkage > + // OK since C++11 because we can refer to an internal linkage decl > + > +void nolinkage() { > + static int guard3; > + a<guard3> d; // { dg-error "constant-expression|invalid" "" { target c++98_only } } > + // { dg-error "constant expression|no linkage" "" { target { c++11 && c++14_down } } .-1 } > + // OK since C++17 since we can now refer to no-linkage decls > +}
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index 08f9c89f1f0..e758ddeb1d5 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -19864,9 +19864,11 @@ cp_parser_template_argument (cp_parser* parser) -- the name of a non-type template-parameter; or - -- the name of an object or function with external linkage... + -- the name of an object or function with external (or internal, + since C++11) linkage... - -- the address of an object or function with external linkage... + -- the address of an object or function with external (or internal, + since C++11) linkage... -- a pointer to member... */ /* Look for a non-type template parameter. */ @@ -19929,11 +19931,16 @@ cp_parser_template_argument (cp_parser* parser) probe = TREE_OPERAND (probe, 1); if (VAR_P (probe)) { - /* A variable without external linkage might still be a + /* A variable without valid linkage might still be a valid constant-expression, so no error is issued here if the external-linkage check fails. */ - if (!address_p && !DECL_EXTERNAL_LINKAGE_P (probe)) - cp_parser_simulate_error (parser); + if (!address_p && cxx_dialect < cxx17) + { + linkage_kind linkage = decl_linkage (probe); + if (linkage != lk_external + && (cxx_dialect < cxx11 || linkage != lk_internal)) + cp_parser_simulate_error (parser); + } } else if (is_overloaded_fn (argument)) /* All overloaded functions are allowed; if the external diff --git a/gcc/testsuite/g++.dg/cpp0x/nontype6.C b/gcc/testsuite/g++.dg/cpp0x/nontype6.C new file mode 100644 index 00000000000..5543d1e8b6d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/nontype6.C @@ -0,0 +1,19 @@ +// PR c++/113266, PR c++/116911 +// { dg-do compile } + +template <int &> struct a {}; +static int guard1; +a<guard1> b; // { dg-error "constant-expression|invalid" "" { target c++98_only } } + +namespace { + int guard2; +} +a<guard2> c; // OK in C++98 because guard2 has external linkage + // OK since C++11 because we can refer to an internal linkage decl + +void nolinkage() { + static int guard3; + a<guard3> d; // { dg-error "constant-expression|invalid" "" { target c++98_only } } + // { dg-error "constant expression|no linkage" "" { target { c++11 && c++14_down } } .-1 } + // OK since C++17 since we can now refer to no-linkage decls +}
Tested on x86_64-pc-linux-gnu, so far just dg.exp with GXX_TESTSUITE_STDS=98,11,14,17,20,23,26,impcx. OK for trunk if full bootstrap + regtest passes? -- >8 -- [temp.arg.nontype] changed in C++11 to allow naming internal-linkage variables and functions. We currently already handle internal-linkage functions, but variables were missed; this patch updates this. PR c++/113266 PR c++/116911 gcc/cp/ChangeLog: * parser.cc (cp_parser_template_argument): Allow internal-linkage variables since C++11. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/nontype6.C: New test. Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com> --- gcc/cp/parser.cc | 17 ++++++++++++----- gcc/testsuite/g++.dg/cpp0x/nontype6.C | 19 +++++++++++++++++++ 2 files changed, 31 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/nontype6.C