diff options
| author | Richard Sandiford <richard.sandiford@arm.com> | 2019-11-13 08:42:56 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2019-11-13 08:42:56 +0000 |
| commit | ae83b9deb87787371cd94b4417e160d41dd0322c (patch) | |
| tree | 26bc42e873c9153d6f8a4a953debfdb868a4aca3 /gcc/cp/cp-tree.h | |
| parent | 9b6e95d30e321c4d0e1355a3f20b88ef2ea29785 (diff) | |
| download | gcc-ae83b9deb87787371cd94b4417e160d41dd0322c.zip gcc-ae83b9deb87787371cd94b4417e160d41dd0322c.tar.gz gcc-ae83b9deb87787371cd94b4417e160d41dd0322c.tar.bz2 | |
[C++] Fix interaction between aka changes and DR1558 (PR92206)
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 safely strip aliases with
dependent template parameters.
2019-11-13 Richard Sandiford <richard.sandiford@arm.com>
gcc/cp/
PR c++/92206
* cp-tree.h (STF_STRIP_DEPENDENT): New constant.
* tree.c (strip_typedefs): Add STF_STRIP_DEPENDENT 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/cpp0x/alias-decl-pr92206-1.C: New test.
* g++.dg/cpp0x/alias-decl-pr92206-2.C: Likewise.
* g++.dg/cpp0x/alias-decl-pr92206-3.C: Likewise.
From-SVN: r278119
Diffstat (limited to 'gcc/cp/cp-tree.h')
| -rw-r--r-- | gcc/cp/cp-tree.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index adc021b..42afe1b 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -5759,8 +5759,13 @@ enum auto_deduction_context STF_USER_VISIBLE: use heuristics to try to avoid stripping user-facing aliases of internal details. This is intended for diagnostics, - where it should (for example) give more useful "aka" types. */ + where it should (for example) give more useful "aka" types. + + STF_STRIP_DEPENDENT: allow the stripping of aliases with dependent + template parameters, relying on code elsewhere to report any + appropriate diagnostics. */ const unsigned int STF_USER_VISIBLE = 1U; +const unsigned int STF_STRIP_DEPENDENT = 1U << 1; /* Returns the TEMPLATE_DECL associated to a TEMPLATE_TEMPLATE_PARM node. */ |