On Mon, Feb 15, 2016 at 9:42 AM, Patrick Palka <patr...@parcs.ath.cx> wrote:
> On Mon, Feb 8, 2016 at 12:19 AM, Patrick Palka <patr...@parcs.ath.cx> wrote:
>> Here, we are calling template_class_depth on a FIELD_DECL corresponding
>> to a lambda that is used inside variable template. template_class_depth
>> however does not see that this FIELD_DECL is used inside a variable
>> template binding because its chain of DECL_CONTEXTs does not include the
>> corresponding VAR_DECL. So template_class_depth returns the wrong
>> template nesting level which causes its callers to malfunction. In
>> particular we strip a template argument level in
>> tsubst_copy [FIELD_DECL] when we shouldn't have.
>>
>> This patch makes template_class_depth look at a lambda type's
>> LAMBDA_TYPE_EXTRA_SCOPE field instead of its TYPE_CONTEXT, so that it
>> can iterate into an enclosing variable template, if applicable.
>>
>> Tested on x86_64-pc-linux gnu, no new regressions. Also tested against
>> Boost. Is this OK to commit?
>>
>> gcc/cp/ChangeLog:
>>
>> PR c++/66786
>> * pt.c (template_class_depth): Given a lambda type, iterate
>> into its LAMBDA_TYPE_EXTRA_SCOPE field instead of its
>> TYPE_CONTEXT. Given a VAR_DECL, iterate into its
>> CP_DECL_CONTEXT.
>>
>> gcc/testsuite/ChangeLog:
>>
>> PR c++/66786
>> * g++.dg/cpp1y/var-templ48.C: New test.
>> * g++.dg/cpp1y/var-templ49.C: New test.
>> ---
>> gcc/cp/pt.c | 12 ++++++++----
>> gcc/testsuite/g++.dg/cpp1y/var-templ48.C | 5 +++++
>> gcc/testsuite/g++.dg/cpp1y/var-templ49.C | 9 +++++++++
>> 3 files changed, 22 insertions(+), 4 deletions(-)
>> create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ48.C
>> create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ49.C
>>
>> diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
>> index 4d405cf..5c344c1 100644
>> --- a/gcc/cp/pt.c
>> +++ b/gcc/cp/pt.c
>> @@ -369,16 +369,20 @@ template_class_depth (tree type)
>> {
>> int depth;
>>
>> - for (depth = 0;
>> - type && TREE_CODE (type) != NAMESPACE_DECL;
>> - type = (TREE_CODE (type) == FUNCTION_DECL)
>> - ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
>> + for (depth = 0; type && TREE_CODE (type) != NAMESPACE_DECL; )
>> {
>> tree tinfo = get_template_info (type);
>>
>> if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
>> && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
>> ++depth;
>> +
>> + if (VAR_OR_FUNCTION_DECL_P (type))
>> + type = CP_DECL_CONTEXT (type);
>> + else if (LAMBDA_TYPE_P (type))
>> + type = LAMBDA_TYPE_EXTRA_SCOPE (type);
>> + else
>> + type = CP_TYPE_CONTEXT (type);
>> }
>>
>> return depth;
>> diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
>> b/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
>> new file mode 100644
>> index 0000000..f0c7693
>> --- /dev/null
>> +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
>> @@ -0,0 +1,5 @@
>> +// PR c++/66786
>> +// { dg-do compile { target c++14 } }
>> +
>> +template <typename... T> auto list = [](T... xs) { [=](auto f) { f(xs...);
>> }; };
>> +int main() { list<int>(0); }
>> diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
>> b/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
>> new file mode 100644
>> index 0000000..cd3f230
>> --- /dev/null
>> +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
>> @@ -0,0 +1,9 @@
>> +// PR c++/66786
>> +// { dg-do compile { target c++14 } }
>> +
>> +int f (int, bool);
>> +
>> +template <typename>
>> +auto list = [](auto... xs) { return [=](auto f, auto... ys) { return
>> f(xs..., ys...); }; };
>> +
>> +const int &a = list<int>(0, true)(f);
>> --
>> 2.7.1.257.g925a48d
>>
>
> Ping.
Ping
