[Bug c++/53540] C++11: using fails to be equivalent to typedef

[dodji at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53540

--- Comment #8 from Dodji Seketeli <dodji at gcc dot gnu.org> 2012-10-10 10:44:02 UTC ---
Author: dodji
Date: Wed Oct 10 10:43:53 2012
New Revision: 192304

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192304
Log:
PR c++/53540 - using fails to be equivalent to typedef

In the example of this problem report, during the substituting of int
into 'function', tsubst_aggr_type fails for the alias ctxt1.  This is
because TYPE_TEMPLATE_INFO looks for the TEMPLATE_INFO of the ctxt1
alias at the wrong place and was wrongly finding it to be NULL.
Namely, it was looking for it in the DECL_TEMPLATE_INFO of the
declaration of the type -- as if ctxt1 was an alias template
specialization -- rather than looking for it in its
CLASSTYPE_TEMPLATE_INFO.

Fixed thus.  The other hunks of the patch are a cleanup to make a
better use of alias_template_specialization_p.

Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.

gcc/cp

    * cp-tree.h (TYPE_TEMPLATE_INFO): For an alias that is not an
    instance of alias template, don't look for its TEMPLATE_INFO in
    its declaration.
    (alias_template_specialization_p): Take const_tree.
    * pt.c (alias_template_specialization_p): Take a const_tree.
    Don't call primary_template_instantiation_p.
    (primary_template_instantiation_p): Call
    alias_template_specialization_p.

gcc/testsuite/

    * g++.dg/cpp0x/alias-decl-24.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/alias-decl-24.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/ChangeLog