c++: Fix up attribute handling in methods in templates [PR100872]

The following testcase FAILs because a dependent (late) attribute is never
tsubsted.  While the testcase is OpenMP, I think it is a generic C++ FE problem
that could affect any other dependent attribute.

apply_late_template_attributes documents that it relies on
  /* save_template_attributes puts the dependent attributes at the beginning of
     the list; find the non-dependent ones.  */
The "operator binding" attributes that are sometimes added are added to the
head of DECL_ATTRIBUTES list though and because it doesn't have
ATTR_IS_DEPENDENT set it violates this requirement.

The following patch fixes it by adding that attribute after all
ATTR_IS_DEPENDENT attributes.  I'm not 100% sure if DECL_ATTRIBUTES can't be
shared by multiple functions (e.g. the cdtor clones), but the code uses
later remove_attribute which could break that too.

Other option would be to copy_list the ATTR_IS_DEPENDENT portion of the
DECL_ATTRIBUTES list if we need to do this, that would be the same as this
patch but replace that *ap = op_attr; at the end with
      *ap = NULL_TREE;
      DECL_ATTRIBUTES (cfn) = chainon (copy_list (DECL_ATTRIBUTES (cfn)),
                                       op_attr);
Or perhaps set ATTR_IS_DEPENDENT on the "operator bindings" attribute,
though it would need to be studied what would it try to do with the
attribute during tsubst.

2021-06-04  Jakub Jelinek  <jakub@redhat.com>

	PR c++/100872
	* name-lookup.c (maybe_save_operator_binding): Add op_attr after all
	ATTR_IS_DEPENDENT attributes in the DECL_ATTRIBUTES list rather than
	to the start.

	* g++.dg/gomp/declare-simd-8.C: New test.

0 files changed, 0 insertions, 0 deletions