| Message ID | 1435430233-12716-1-git-send-email-patrick@parcs.ath.cx |
|---|---|
| State | New |
| Headers | show |
On Sat, Jun 27, 2015 at 2:37 PM, Patrick Palka <patrick@parcs.ath.cx> wrote: > This patch makes coerce_template_template_parm consider a coercion > successful if the result of calling tsubst on a template template parm > is a dependent type even when the desired argument type is non-dependent. > > For the test case below, TREE_TYPE (parm) is B and TREE_TYPE (arg) is > int. After calling tsubst on the parm the resulting type is still B, a > dependent type. Without checking that the resulting type is dependent, > the function would return 0 because same_type_p would return false. > > Bootstrap + regtest of this change was successful on > x86_64-unknown-linux-gnu. Does this patch look OK? > > gcc/cp/ChangeLog: > > * pt.c (coerce_template_template_parm) [PARM_DECL]: Don't > return 0 if tsubst returns a dependent type. > > gcc/testsuite/ChangeLog: > > * g++.dg/template/pr66686.C: New test. > --- > gcc/cp/pt.c | 12 +++++++----- > gcc/testsuite/g++.dg/template/pr66686.C | 15 +++++++++++++++ > 2 files changed, 22 insertions(+), 5 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/template/pr66686.C > > diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c > index 2b37460..d7768a8 100644 > --- a/gcc/cp/pt.c > +++ b/gcc/cp/pt.c > @@ -6357,11 +6357,13 @@ coerce_template_template_parm (tree parm, > D<int, C> d; > > i.e. the parameter list of TT depends on earlier parameters. */ > - if (!uses_template_parms (TREE_TYPE (arg)) > - && !same_type_p > - (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl), > - TREE_TYPE (arg))) > - return 0; > + if (!uses_template_parms (TREE_TYPE (arg))) > + { > + tree t = tsubst (TREE_TYPE (parm), outer_args, complain, in_decl); > + if (!uses_template_parms (t) > + && !same_type_p (t, TREE_TYPE (arg))) > + return 0; > + } > > if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg)) > && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) > diff --git a/gcc/testsuite/g++.dg/template/pr66686.C b/gcc/testsuite/g++.dg/template/pr66686.C > new file mode 100644 > index 0000000..d8aea62 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/template/pr66686.C > @@ -0,0 +1,15 @@ > +// PR c++/66686 > + > +template <int> > +struct Y { }; > + > +template <class B, template <template <B> class Z> class C> > +struct X > +{ > + C<Y> a; // { dg-bogus "mismatch" } > +}; > + > +template <template <int> class> > +struct A { }; > + > +X<int, A> a; > -- > 2.5.0.rc0.5.g91e10c5.dirty > Early ping because I forgot to CC Jason.
OK. Jason
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 2b37460..d7768a8 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -6357,11 +6357,13 @@ coerce_template_template_parm (tree parm, D<int, C> d; i.e. the parameter list of TT depends on earlier parameters. */ - if (!uses_template_parms (TREE_TYPE (arg)) - && !same_type_p - (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl), - TREE_TYPE (arg))) - return 0; + if (!uses_template_parms (TREE_TYPE (arg))) + { + tree t = tsubst (TREE_TYPE (parm), outer_args, complain, in_decl); + if (!uses_template_parms (t) + && !same_type_p (t, TREE_TYPE (arg))) + return 0; + } if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg)) && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) diff --git a/gcc/testsuite/g++.dg/template/pr66686.C b/gcc/testsuite/g++.dg/template/pr66686.C new file mode 100644 index 0000000..d8aea62 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/pr66686.C @@ -0,0 +1,15 @@ +// PR c++/66686 + +template <int> +struct Y { }; + +template <class B, template <template <B> class Z> class C> +struct X +{ + C<Y> a; // { dg-bogus "mismatch" } +}; + +template <template <int> class> +struct A { }; + +X<int, A> a;