| Message ID | 20211001201022.2678056-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: ttp variadic constraint subsumption [PR99904] | expand |
On 10/1/21 16:10, Patrick Palka wrote: > Here we're crashing when level-lowering the variadic constraints on the > template template parameter TT because tsubst_pack_expansion expects > processing_template_decl to be set during a partial substitution. > > bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk/11? Also tested on cmcstl2 and range-v3. OK. > PR c++/99904 > > gcc/cp/ChangeLog: > > * pt.c (is_compatible_template_arg): Set processing_template_decl > around tsubst_constraint_info. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-ttp4.C: New test. > --- > gcc/cp/pt.c | 2 ++ > gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C | 9 +++++++++ > 2 files changed, 11 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C > > diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c > index 1dcdffe322a..f950f4a21b7 100644 > --- a/gcc/cp/pt.c > +++ b/gcc/cp/pt.c > @@ -8223,8 +8223,10 @@ is_compatible_template_arg (tree parm, tree arg) > { > tree aparms = DECL_INNERMOST_TEMPLATE_PARMS (arg); > new_args = template_parms_level_to_args (aparms); > + ++processing_template_decl; > parm_cons = tsubst_constraint_info (parm_cons, new_args, > tf_none, NULL_TREE); > + --processing_template_decl; > if (parm_cons == error_mark_node) > return false; > } > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C > new file mode 100644 > index 00000000000..cf3e71ea974 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C > @@ -0,0 +1,9 @@ > +// PR c++/99904 > +// { dg-do compile { target c++20 } } > + > +template<class... Ts> concept C = (Ts::value && ...); > +template<class... Ts> requires C<Ts...> struct A; > +template<class T> requires true struct B; > +template<template<class... Ts> requires C<Ts...> class TT> struct S; > +using ty1 = S<A>; > +using ty2 = S<B>; // { dg-error "constraint" } TT's constraints don't subsume B's >
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 1dcdffe322a..f950f4a21b7 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -8223,8 +8223,10 @@ is_compatible_template_arg (tree parm, tree arg) { tree aparms = DECL_INNERMOST_TEMPLATE_PARMS (arg); new_args = template_parms_level_to_args (aparms); + ++processing_template_decl; parm_cons = tsubst_constraint_info (parm_cons, new_args, tf_none, NULL_TREE); + --processing_template_decl; if (parm_cons == error_mark_node) return false; } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C new file mode 100644 index 00000000000..cf3e71ea974 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp4.C @@ -0,0 +1,9 @@ +// PR c++/99904 +// { dg-do compile { target c++20 } } + +template<class... Ts> concept C = (Ts::value && ...); +template<class... Ts> requires C<Ts...> struct A; +template<class T> requires true struct B; +template<template<class... Ts> requires C<Ts...> class TT> struct S; +using ty1 = S<A>; +using ty2 = S<B>; // { dg-error "constraint" } TT's constraints don't subsume B's