Message ID | 20230314164146.1470993-2-ppalka@redhat.com |
---|---|
State | New |
Headers | show |
Series | [1/2] c++: constrained template friend class matching [PR96830] | expand |
On 3/14/23 12:41, Patrick Palka wrote: > When redeclaring a member of a constrained class template, we need to > repeat the class's constraints, but it turns out we don't verify > anywhere that the repeated constraints match the class's constraints. > A safe place to do so seems to be in push_template_decl, nearby a > similar consistency check for the template parameter list length of a > redeclaration. > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk/12? Both patches are OK for trunk, but not 12; we tend not to backport fixes for accepts-invalid bugs, especially if they aren't regressions. We don't want to add new diagnostics to an active release branch. > PR c++/96830 > > gcc/cp/ChangeLog: > > * pt.cc (push_inline_template_parms_recursive): Set > TEMPLATE_PARMS_CONSTRAINTS. > (push_template_decl): For a redeclaration, verify constraints > for each enclosing template scope match those of the original > template declaratation. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-class5.C: New test. > * g++.dg/cpp2a/concepts-class5a.C: New test. > --- > gcc/cp/pt.cc | 26 +++++++++++++ > gcc/testsuite/g++.dg/cpp2a/concepts-class5.C | 37 ++++++++++++++++++ > gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C | 38 +++++++++++++++++++ > 3 files changed, 101 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-class5.C > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > index 053cc52b285..370a4f70f08 100644 > --- a/gcc/cp/pt.cc > +++ b/gcc/cp/pt.cc > @@ -471,6 +471,8 @@ push_inline_template_parms_recursive (tree parmlist, int levels) > current_template_parms > = tree_cons (size_int (current_template_depth + 1), > parms, current_template_parms); > + TEMPLATE_PARMS_CONSTRAINTS (current_template_parms) > + = TEMPLATE_PARMS_CONSTRAINTS (parmlist); > TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1; > > begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec, > @@ -6134,6 +6136,30 @@ push_template_decl (tree decl, bool is_friend) > DECL_INTERFACE_KNOWN (decl) = 1; > return error_mark_node; > } > + > + /* Check that the constraints for each enclosing template scope are > + consistent with the original template declaration. */ > + if (flag_concepts) > + { > + tree decl_parms = DECL_TEMPLATE_PARMS (tmpl); > + tree scope_parms = current_template_parms; > + if (PRIMARY_TEMPLATE_P (tmpl)) > + { > + decl_parms = TREE_CHAIN (decl_parms); > + scope_parms = TREE_CHAIN (scope_parms); > + } > + while (decl_parms) > + { > + if (!template_requirements_equivalent_p (decl_parms, scope_parms)) > + { > + error ("redeclaration of %qD with different constraints", > + TPARMS_PRIMARY_TEMPLATE (TREE_VALUE (decl_parms))); > + break; > + } > + decl_parms = TREE_CHAIN (decl_parms); > + scope_parms = TREE_CHAIN (scope_parms); > + } > + } > } > > gcc_checking_assert (!tmpl || DECL_TEMPLATE_RESULT (tmpl) == decl); > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C > new file mode 100644 > index 00000000000..5d893d9f6a7 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C > @@ -0,0 +1,37 @@ > +// PR c++/96830 > +// { dg-do compile { target c++20 } } > + > +template<class T> concept C = true; > + > +template<C T> requires true > +struct A { > + void f(); > + template<class U> void g(); > + > + struct B; > + template<class U> struct C; > + > + static int D; > + template<class U> static int E; > +}; > + > +template<C T> > +void A<T>::f() { } // { dg-error "different constraints" } > + > +template<class T> requires true > +template<class U> > +void A<T>::g() { } // { dg-error "different constraints" } > + > +template<C T> requires (!!true) > +struct A<T>::B { }; // { dg-error "different constraints" } > + > +template<class T> requires true > +template<class U> > +struct A<T>::C { }; // { dg-error "different constraints" } > + > +template<C T> > +int A<T>::D = 0; // { dg-error "different constraints" } > + > +template<class T> requires true > +template<class U> > +int A<T>::E = 0; // { dg-error "different constraints" } > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C b/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C > new file mode 100644 > index 00000000000..a6a3684c258 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C > @@ -0,0 +1,38 @@ > +// PR c++/96830 > +// A valid version of concepts-class5.C. > +// { dg-do compile { target c++20 } } > + > +template<class T> concept C = true; > + > +template<C T> requires true > +struct A { > + void f(); > + template<class U> void g(); > + > + struct B; > + template<class U> struct C; > + > + static int D; > + template<class U> static int E; > +}; > + > +template<C T> requires true > +void A<T>::f() { } > + > +template<C T> requires true > +template<class U> > +void A<T>::g() { } > + > +template<C T> requires true > +struct A<T>::B { }; > + > +template<C T> requires true > +template<class U> > +struct A<T>::C { }; > + > +template<C T> requires true > +int A<T>::D = 0; > + > +template<C T> requires true > +template<class U> > +int A<T>::E = 0;
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 053cc52b285..370a4f70f08 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -471,6 +471,8 @@ push_inline_template_parms_recursive (tree parmlist, int levels) current_template_parms = tree_cons (size_int (current_template_depth + 1), parms, current_template_parms); + TEMPLATE_PARMS_CONSTRAINTS (current_template_parms) + = TEMPLATE_PARMS_CONSTRAINTS (parmlist); TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1; begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec, @@ -6134,6 +6136,30 @@ push_template_decl (tree decl, bool is_friend) DECL_INTERFACE_KNOWN (decl) = 1; return error_mark_node; } + + /* Check that the constraints for each enclosing template scope are + consistent with the original template declaration. */ + if (flag_concepts) + { + tree decl_parms = DECL_TEMPLATE_PARMS (tmpl); + tree scope_parms = current_template_parms; + if (PRIMARY_TEMPLATE_P (tmpl)) + { + decl_parms = TREE_CHAIN (decl_parms); + scope_parms = TREE_CHAIN (scope_parms); + } + while (decl_parms) + { + if (!template_requirements_equivalent_p (decl_parms, scope_parms)) + { + error ("redeclaration of %qD with different constraints", + TPARMS_PRIMARY_TEMPLATE (TREE_VALUE (decl_parms))); + break; + } + decl_parms = TREE_CHAIN (decl_parms); + scope_parms = TREE_CHAIN (scope_parms); + } + } } gcc_checking_assert (!tmpl || DECL_TEMPLATE_RESULT (tmpl) == decl); diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C new file mode 100644 index 00000000000..5d893d9f6a7 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class5.C @@ -0,0 +1,37 @@ +// PR c++/96830 +// { dg-do compile { target c++20 } } + +template<class T> concept C = true; + +template<C T> requires true +struct A { + void f(); + template<class U> void g(); + + struct B; + template<class U> struct C; + + static int D; + template<class U> static int E; +}; + +template<C T> +void A<T>::f() { } // { dg-error "different constraints" } + +template<class T> requires true +template<class U> +void A<T>::g() { } // { dg-error "different constraints" } + +template<C T> requires (!!true) +struct A<T>::B { }; // { dg-error "different constraints" } + +template<class T> requires true +template<class U> +struct A<T>::C { }; // { dg-error "different constraints" } + +template<C T> +int A<T>::D = 0; // { dg-error "different constraints" } + +template<class T> requires true +template<class U> +int A<T>::E = 0; // { dg-error "different constraints" } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C b/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C new file mode 100644 index 00000000000..a6a3684c258 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class5a.C @@ -0,0 +1,38 @@ +// PR c++/96830 +// A valid version of concepts-class5.C. +// { dg-do compile { target c++20 } } + +template<class T> concept C = true; + +template<C T> requires true +struct A { + void f(); + template<class U> void g(); + + struct B; + template<class U> struct C; + + static int D; + template<class U> static int E; +}; + +template<C T> requires true +void A<T>::f() { } + +template<C T> requires true +template<class U> +void A<T>::g() { } + +template<C T> requires true +struct A<T>::B { }; + +template<C T> requires true +template<class U> +struct A<T>::C { }; + +template<C T> requires true +int A<T>::D = 0; + +template<C T> requires true +template<class U> +int A<T>::E = 0;