On 10/25/19 2:53 PM, Richard Sandiford wrote:
One of the changes in r277281 was to make the typedef variant
handling in strip_typedefs pass the raw DECL_ORIGINAL_TYPE to the
recursive call, instead of applying TYPE_MAIN_VARIANT first.
This PR shows that that interacts badly with the implementation
of DR1558, because we then refuse to strip aliases with dependent
template parameters and trip:
gcc_assert (!typedef_variant_p (result)
|| ((flags & STF_USER_VISIBLE)
&& !user_facing_original_type_p (result)));
Keeping the current behaviour but suppressing the ICE leads to a
duplicate error (the dg-bogus in the first test), so that didn't
seem like a good fix.
I assume keeping the alias should never actually be necessary for
DECL_ORIGINAL_TYPEs, because it will already have been checked
somewhere, even for implicit TYPE_DECLs. This patch therefore
passes a flag to say that we can assume the type is validated
elsewhere.
It seems a rather clunky fix, sorry, but restoring the
TYPE_MAIN_VARIANT (...) isn't compatible with the aka stuff.
Bootstrapped & regression-tested on aarch64-linux-gnu. OK to install?
2019-10-25 Richard Sandiford <richard.sandif...@arm.com>
gcc/cp/
PR c++/92206
* cp-tree.h (STF_ASSUME_VALID): New constant.
Let's call this STF_STRIP_DEPENDENT.
* tree.c (strip_typedefs): Add STF_ASSUME_VALID to the flags
when calling strip_typedefs recursively on a DECL_ORIGINAL_TYPE.
Don't apply the fix for DR1558 in that case; allow aliases with
dependent template parameters to be stripped instead.
gcc/testsuite/
PR c++/92206
* g++.dg/pr92206-1.C: New test.
* g++.dg/pr92206-2.C: Likewise.
* g++.dg/pr92206-3.C: Likewise.
Let's call these g++.dg/cpp0x/alias-decl-pr92206*.
OK with those changes.
Jason
