c++: constant non-dep init folding vs FIELD_DECL access [PR97740]HEADtrunkmaster

Here although the local templated variables x and y have the same
reduced constant value, only x's initializer {a.get()} is well-formed
as written since A::m has private access.  We correctly reject y's
initializer {&a.m} (at instantiation time), but we also reject x's
initializer because we happen to constant fold it ahead of time, which
means at instantiation time it's already represented as a COMPONENT_REF
to a FIELD_DECL, and so when substituting this COMPONENT_REF we naively
double check that the given FIELD_DECL is accessible, which fails.

This patch sidesteps around this particular issue by not checking access
when substituting a COMPONENT_REF to a FIELD_DECL.  If the target of a
COMPONENT_REF is already a FIELD_DECL (i.e. before substitution), then I
think we can assume access has been already checked appropriately.

	PR c++/97740

gcc/cp/ChangeLog:

	* pt.cc (tsubst_expr) <case COMPONENT_REF>: Don't check access
	when the given member is already a FIELD_DECL.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/constexpr-97740a.C: New test.
	* g++.dg/cpp0x/constexpr-97740b.C: New test.

Reviewed-by: Jason Merrill <jason@redhat.com>

0 files changed, 0 insertions, 0 deletions