| Message ID | 20210928191541.3143405-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: ttp matching with constrained auto parm [PR99909] | expand |
On 9/28/21 15:15, Patrick Palka wrote: > Here, when unifying TT with S, processing_template_decl is unset, and > this foils the dependence checks in do_auto_deduction for avoiding > checking constraints on an auto when the initializer is dependent. > > This patch fixes this issue by making sure processing_template_decl is > set during the call to unify from coerce_template_template_parms; this > seems sensible because we're unifying one set of template parameters > with another, so we're dealing with templated trees throughout. > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk? OK. > PR c++/99909 > > gcc/cp/ChangeLog: > > * pt.c (coerce_template_template_parms): Keep > processing_template_decl set during the call to unify as well. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-ttp3.C: New test. > --- > gcc/cp/pt.c | 4 ++-- > gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C | 11 +++++++++++ > 2 files changed, 13 insertions(+), 2 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C > > diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c > index 41fa7ed5e43..1dcdffe322a 100644 > --- a/gcc/cp/pt.c > +++ b/gcc/cp/pt.c > @@ -7994,12 +7994,12 @@ coerce_template_template_parms (tree parm_parms, > /* So coerce P's args to apply to A's parms, and then deduce between A's > args and the converted args. If that succeeds, A is at least as > specialized as P, so they match.*/ > + processing_template_decl_sentinel ptds (/*reset*/false); > + ++processing_template_decl; > tree pargs = template_parms_level_to_args (parm_parms); > pargs = add_outermost_template_args (outer_args, pargs); > - ++processing_template_decl; > pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none, > /*require_all*/true, /*use_default*/true); > - --processing_template_decl; > if (pargs != error_mark_node) > { > tree targs = make_tree_vec (nargs); > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C > new file mode 100644 > index 00000000000..898524e0dfa > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C > @@ -0,0 +1,11 @@ > +// PR c++/99909 > +// { dg-do compile { target c++20 } } > + > +template<class T> constexpr bool always_true = true; > +template<class T> concept C = always_true<T>; > + > +template<C auto> struct S { }; > + > +template<template<auto> class TT> void f() { } > + > +template void f<S>(); >
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 41fa7ed5e43..1dcdffe322a 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -7994,12 +7994,12 @@ coerce_template_template_parms (tree parm_parms, /* So coerce P's args to apply to A's parms, and then deduce between A's args and the converted args. If that succeeds, A is at least as specialized as P, so they match.*/ + processing_template_decl_sentinel ptds (/*reset*/false); + ++processing_template_decl; tree pargs = template_parms_level_to_args (parm_parms); pargs = add_outermost_template_args (outer_args, pargs); - ++processing_template_decl; pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none, /*require_all*/true, /*use_default*/true); - --processing_template_decl; if (pargs != error_mark_node) { tree targs = make_tree_vec (nargs); diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C new file mode 100644 index 00000000000..898524e0dfa --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp3.C @@ -0,0 +1,11 @@ +// PR c++/99909 +// { dg-do compile { target c++20 } } + +template<class T> constexpr bool always_true = true; +template<class T> concept C = always_true<T>; + +template<C auto> struct S { }; + +template<template<auto> class TT> void f() { } + +template void f<S>();