| Message ID | 20220328132904.4071925-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: ICE during constrained template friend matching [PR105064] | expand |
On 3/28/22 09:29, Patrick Palka wrote: > Here during declaration matching for the two constrained template > friends, we crash from maybe_substitute_reqs_for because the second > friend doesn't yet have DECL_TEMPLATE_INFO set (we're being called > indirectly from push_template_decl). > > As far as I can tell, this situation happens only when declaring a > constrained template friend within a non-template class (as in the > testcase), in which case the substitution would be a no-op anyway, so it > should be safe to just skip it. To that end this patch rearranges > maybe_substitute_reqs_for to gracefully handle DECL_TEMPLATE_INFO being > empty. > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk/11? OK. > PR c++/105064 > > gcc/cp/ChangeLog: > > * constraint.cc (maybe_substitute_reqs_for): Don't assume > DECL_TEMPLATE_INFO is set. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-friend9.C: New test. > --- > gcc/cp/constraint.cc | 13 ++++--------- > gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C | 12 ++++++++++++ > 2 files changed, 16 insertions(+), 9 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C > > diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc > index e14578b1721..c5a991b9e71 100644 > --- a/gcc/cp/constraint.cc > +++ b/gcc/cp/constraint.cc > @@ -1268,20 +1268,15 @@ remove_constraints (tree t) > for declaration matching. */ > > tree > -maybe_substitute_reqs_for (tree reqs, const_tree decl_) > +maybe_substitute_reqs_for (tree reqs, const_tree decl) > { > if (reqs == NULL_TREE) > return NULL_TREE; > > - tree decl = CONST_CAST_TREE (decl_); > - tree result = STRIP_TEMPLATE (decl); > - > - if (DECL_UNIQUE_FRIEND_P (result)) > + decl = STRIP_TEMPLATE (decl); > + if (DECL_UNIQUE_FRIEND_P (decl) && DECL_TEMPLATE_INFO (decl)) > { > - tree tmpl = decl; > - if (TREE_CODE (decl) != TEMPLATE_DECL) > - tmpl = DECL_TI_TEMPLATE (result); > + tree tmpl = DECL_TI_TEMPLATE (decl); > tree gargs = generic_targs_for (tmpl); > processing_template_decl_sentinel s; > if (uses_template_parms (gargs)) > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C b/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C > new file mode 100644 > index 00000000000..09054d23d5d > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C > @@ -0,0 +1,12 @@ > +// PR c++/105064 > +// { dg-do compile { target c++20 } } > + > +struct A { > + template<class T> > + friend void f(T) requires true; > +}; > + > +struct B { > + template<class T> > + friend void f(T) requires true; > +};
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc index e14578b1721..c5a991b9e71 100644 --- a/gcc/cp/constraint.cc +++ b/gcc/cp/constraint.cc @@ -1268,20 +1268,15 @@ remove_constraints (tree t) for declaration matching. */ tree -maybe_substitute_reqs_for (tree reqs, const_tree decl_) +maybe_substitute_reqs_for (tree reqs, const_tree decl) { if (reqs == NULL_TREE) return NULL_TREE; - tree decl = CONST_CAST_TREE (decl_); - tree result = STRIP_TEMPLATE (decl); - - if (DECL_UNIQUE_FRIEND_P (result)) + decl = STRIP_TEMPLATE (decl); + if (DECL_UNIQUE_FRIEND_P (decl) && DECL_TEMPLATE_INFO (decl)) { - tree tmpl = decl; - if (TREE_CODE (decl) != TEMPLATE_DECL) - tmpl = DECL_TI_TEMPLATE (result); - + tree tmpl = DECL_TI_TEMPLATE (decl); tree gargs = generic_targs_for (tmpl); processing_template_decl_sentinel s; if (uses_template_parms (gargs)) diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C b/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C new file mode 100644 index 00000000000..09054d23d5d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-friend9.C @@ -0,0 +1,12 @@ +// PR c++/105064 +// { dg-do compile { target c++20 } } + +struct A { + template<class T> + friend void f(T) requires true; +}; + +struct B { + template<class T> + friend void f(T) requires true; +};