[Bug c++/26099] New: support for type traits is not available

[Bug c++/26099] New: support for type traits is not available

[stefaan dot deroeck at gmail dot com]

currently, in <tr1/type_traits>, code exists like:

  template<typename _Tp>
    struct has_trivial_destructor
    : public integral_constant<bool, is_pod<_Tp>::value> { };

It would be nice to have compiler support to detect non-pod types that have a
trivial destructor.  (this would provide support for certain optimizations)


-- 
           Summary: support for type traits is not available
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: stefaan dot deroeck at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-02-04 22:17 -------
Wouldn't it be better to ask the standards committee to add support than asking
GCC to add an extension?

Also what kind of optimizations can you do with a trival destructor?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[stefaan dot deroeck at gmail dot com]

------- Comment #2 from stefaan dot deroeck at gmail dot com  2006-02-04 23:13 -------
When I saw "tr1" in the path, I assumed this referred to the technical report
of the standards committee.  I recognize a technical report is not a standard,
thus I am simply inquiring if there is interest in adding this feature.  

I see code in <bits/stl_construct.h>, function _Destroy, that allows for
optimizations when this support is available. 

A second example, I am myself writing a container class that allows
allocation+construction of chunks of variable size at a time (aiming for lower
computational cost).  When erasing a single element from that container, its
destruction would have to be done immediately, while its memory chunk would
remain allocated.  Some (expensive) bookkeeping has to be done to later
facilitate correct destruction and deallocation of remaining elements when the
container itself is destroyed.  If has_trivial_destructor would be true_type,
all this bookkeeping could be omitted, and on destruction of the container just
the deallocation of all the used memory would be sufficient.  

I am no expert on the implementation details of existing containers, but I
guess similar optimizations throughout libstdc++ are possible.  


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-02-04 23:22 -------
(In reply to comment #2)
> When I saw "tr1" in the path, I assumed this referred to the technical report
> of the standards committee.  I recognize a technical report is not a standard,
> thus I am simply inquiring if there is interest in adding this feature.  

Yes TR1 refers to the technical report which is really just the library part.

The interest should really go to the committe than one implementation.  Now GCC
can add this as an extensions and that can help the discussion/decision to add
it to the standard.  But GCC's view of extensions have changed over the years
and right now it is that extensions are bad and should be avoided.

I am not saying this is not useful after your description of how to speed up
some containers.  
Now the book keeping is not that expensive as it is just an extra bool for each
slot and you can hide most of the book keeping in a secondary class.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #5 from pcarlini at suse dot de  2006-02-04 23:41 -------
Really, what Stefaan is saying is trivially correct and totally sensible. The
only doubt I have is which *specific* shape the compiler support must take. In
fact, I find TR1, 4.9 too vague about that. Then the point would be (I think
Andrew will agree): let's suppose some sort of ""reflection"" becomes part of
the next C++ standard, then the whole core C++ + type_traits becomes absolutely
natural and neat. I think many people would like standardization in this area,
but if C++0x will not include it (a huge number of new features is already
scheduled!), we have to accept ""extensions"" if we want performance and QoI in
the library. This is already happening today in many areas, consider, e.g.,
thread safe locales, math builtins, lots of examples, really.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[stefaan dot deroeck at gmail dot com]

------- Comment #4 from stefaan dot deroeck at gmail dot com  2006-02-04 23:41 -------
> Yes TR1 refers to the technical report which is really just the library part.

For the library to provide this functionality, it has to exist in the compiler,
as a whole, or by a clever combination of language constructs.  Currently, it
doesn't seem to me that this proposal could be implemented using gcc.  

If it is the desire of the gcc developers to adhere to the iso standard and no
more, I don't intend to argue on that, as I currently don't have the means
(free time nor adequate gcc code knowledge) to contribute code. 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[gdr at integrable-solutions dot net]

------- Comment #6 from gdr at integrable-solutions dot net  2006-02-05 03:56 -------
Subject: Re:  support for type traits is not available

"pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:

| The interest should really go to the committe than one
| implementation.  Now GCC can add this as an extensions and that can
| help the discussion/decision to add it to the standard.

I have no doubt many (all?) of of the tr1 traits will be part of C++0x.

I think the PR is a valid request for enhancement, with priority
higher than most requests for enhancements I've seen.

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #7 from pcarlini at suse dot de  2006-02-05 10:22 -------
Confirmed.


-- 

pcarlini at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-02-05 10:22:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #8 from pcarlini at suse dot de  2006-11-21 18:38 -------
Trying to make progress...


-- 

pcarlini at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pcarlini at suse dot de
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[paolo at gcc dot gnu dot org]

------- Comment #9 from paolo at gcc dot gnu dot org  2007-03-30 20:46 -------
Subject: Bug 26099

Author: paolo
Date: Fri Mar 30 20:45:57 2007
New Revision: 123366

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123366
Log:
gcc/
2007-03-30  Paolo Carlini  <pcarlini@suse.de>

        PR c++/26099
        * c-common.h (enum rid): Add RID_HAS_NOTHROW_ASSIGN,
        RID_HAS_NOTHROW_CONSTRUCTOR, RID_HAS_NOTHROW_COPY,
        RID_HAS_TRIVIAL_ASSIGN, RID_HAS_TRIVIAL_CONSTRUCTOR,
        RID_HAS_TRIVIAL_COPY, RID_HAS_TRIVIAL_DESTRUCTOR,
        RID_HAS_VIRTUAL_DESTRUCTOR, RID_IS_ABSTRACT, RID_IS_BASE_OF,
        RID_IS_CONVERTIBLE_TO, RID_IS_CLASS, RID_IS_EMPTY, RID_IS_ENUM,
        RID_IS_POD, RID_IS_POLYMORPHIC, RID_IS_UNION, as
        C++ extensions.
        * doc/extend.texi (Extensions to the C++ Language): Add Type Traits.

gcc/cp/
2007-03-30  Paolo Carlini  <pcarlini@suse.de>

        PR c++/26099
        * cp-tree.h (enum cp_trait_kind, struct tree_trait_expr,
        TRAIT_EXPR_TYPE1, TRAIT_EXPR_TYPE2, TRAIT_EXPR_KIND): Add.
        (enum cp_tree_node_structure_enum, union lang_tree_node): Update.
        (CLASS_TYPE_NON_UNION_P): Add.
        (struct lang_type_class): Add has_complex_dflt.
        (TYPE_HAS_COMPLEX_DFLT, TYPE_HAS_TRIVIAL_DFLT): Add.
        (locate_copy, locate_ctor, locate_dtor, finish_trait_expr): Declare.
        * cp-tree.def: Add TRAIT_EXPR.
        * cp-objcp-common.c (cp_tree_size): Add TRAIT_EXPR case.
        * lex.c (struct resword): Add __has_nothrow_assign,
        __has_nothrow_constructor, __has_nothrow_copy, __has_trivial_assign,
        __has_trivial_constructor, __has_trivial_copy,
        __has_trivial_destructor, __has_virtual_destructor, __is_abstract,
        __is_base_of, __is_class, __is_convertible_to, __is_empty, __is_enum,
        __is_pod, __is_polymorphic, __is_union.
        * parser.c (cp_parser_primary_expression): Deal with the new RIDs.
        (cp_parser_trait_expr): New.
        * semantics.c (finish_trait_expr, trait_expr_value
        classtype_has_nothrow_copy_or_assign_p): New.
        * method.c (locate_copy, locate_ctor, locate_dtor): Do not define
        as static.
        * decl.c (cp_tree_node_structure): Add TRAIT_EXPR.
        * class.c (check_bases, check_field_decl, check_bases_and_members):
        Deal with TYPE_HAS_COMPLEX_DFLT (t) too.
        * pt.c (uses_template_parms, tsubst_copy_and_build,
        value_dependent_expression_p, type_dependent_expression_p): Deal with
        TRAIT_EXPR.
        * tree.c (cp_walk_subtrees): Deal with TRAIT_EXPR.

gcc/testsuite/
2007-03-30  Paolo Carlini  <pcarlini@suse.de>

        PR c++/26099
        * g++.dg/ext/is_base_of.C: New.
        * g++.dg/ext/has_virtual_destructor.C: New.
        * g++.dg/ext/is_polymorphic.C: New.
        * g++.dg/ext/is_base_of_diagnostic.C: New.
        * g++.dg/ext/is_enum.C: New.
        * g++.dg/ext/has_nothrow_assign.C: New.
        * g++.dg/ext/has_nothrow_constructor.C: New.
        * g++.dg/ext/is_empty.C: New.
        * g++.dg/ext/has_trivial_copy.C: New.
        * g++.dg/ext/has_trivial_assign.C: New.
        * g++.dg/ext/is_abstract.C: New.
        * g++.dg/ext/is_pod.C: New.
        * g++.dg/ext/has_nothrow_copy.C: New.
        * g++.dg/ext/is_class.C: New.
        * g++.dg/ext/has_trivial_constructor.C: New.
        * g++.dg/ext/is_union.C: New.
        * g++.dg/ext/has_trivial_destructor.C: New.
        * g++.dg/tree-ssa/pr22444.C: Adjust, avoid __is_pod.
        * g++.dg/template/crash43.C: Likewise.

libstdc++-v3/
2007-03-30  Paolo Carlini  <pcarlini@suse.de>

        PR c++/26099
        * include/bits/cpp_type_traits.h (struct __is_pod, struct __is_empty):
        Remove.
        * include/bits/valarray_array.h: Adjust.
        * include/bits/allocator.h: Likewise.
        * include/bits/stl_tree.h: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/ext/has_nothrow_assign.C
    trunk/gcc/testsuite/g++.dg/ext/has_nothrow_constructor.C
    trunk/gcc/testsuite/g++.dg/ext/has_nothrow_copy.C
    trunk/gcc/testsuite/g++.dg/ext/has_trivial_assign.C
    trunk/gcc/testsuite/g++.dg/ext/has_trivial_constructor.C
    trunk/gcc/testsuite/g++.dg/ext/has_trivial_copy.C
    trunk/gcc/testsuite/g++.dg/ext/has_trivial_destructor.C
    trunk/gcc/testsuite/g++.dg/ext/has_virtual_destructor.C
    trunk/gcc/testsuite/g++.dg/ext/is_abstract.C
    trunk/gcc/testsuite/g++.dg/ext/is_base_of.C
    trunk/gcc/testsuite/g++.dg/ext/is_base_of_diagnostic.C
    trunk/gcc/testsuite/g++.dg/ext/is_class.C
    trunk/gcc/testsuite/g++.dg/ext/is_empty.C
    trunk/gcc/testsuite/g++.dg/ext/is_enum.C
    trunk/gcc/testsuite/g++.dg/ext/is_pod.C
    trunk/gcc/testsuite/g++.dg/ext/is_polymorphic.C
    trunk/gcc/testsuite/g++.dg/ext/is_union.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-common.h
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/class.c
    trunk/gcc/cp/cp-objcp-common.c
    trunk/gcc/cp/cp-tree.def
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/decl.c
    trunk/gcc/cp/lex.c
    trunk/gcc/cp/method.c
    trunk/gcc/cp/parser.c
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/semantics.c
    trunk/gcc/cp/tree.c
    trunk/gcc/doc/extend.texi
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/template/crash43.C
    trunk/gcc/testsuite/g++.dg/tree-ssa/pr22444.C
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/bits/allocator.h
    trunk/libstdc++-v3/include/bits/cpp_type_traits.h
    trunk/libstdc++-v3/include/bits/stl_tree.h
    trunk/libstdc++-v3/include/bits/valarray_array.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #10 from ghazi at gcc dot gnu dot org  2008-01-27 05:07 -------
Hi Paolo, three of the tests you added for this enhancement have execute
failures on i686-unknown-linux-gnu and x86_64-unknown-linux-gnu on mainline
when compiled with -fpic/-fPIC.  Is there some valid reason they should not
pass?  These are the last pic-specific errors on mainline (that I haven't
already patched) so I'd really like to zap them somehow.

I imagine these failures are important since the audit trail talks a lot about
using this feature in the std library which is compiled pic.  Would you please
take a look and let me know what you think needs to be done?
Thanks.

FAIL: g++.dg/ext/has_nothrow_assign.C execution test
FAIL: g++.dg/ext/has_nothrow_constructor.C execution test
FAIL: g++.dg/ext/has_nothrow_copy.C execution test

http://gcc.gnu.org/ml/gcc-testresults/2008-01/msg01322.html
http://gcc.gnu.org/ml/gcc-testresults/2008-01/msg01290.html


-- 

ghazi at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ghazi at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #11 from ghazi at gcc dot gnu dot org  2008-01-27 05:19 -------
>From the -fpic/-fPIC logfile:

has_nothrow_assign.exe: [...]/has_nothrow_assign.C:139: int main(): Assertion
`(__has_nothrow_assign(E) && f<E>() && My<E>().f() && My2<E>::trait &&
My3<E>().f())' failed.
FAIL: g++.dg/ext/has_nothrow_assign.C execution test

has_nothrow_constructor.exe: [...]/has_nothrow_constructor.C:100: int main():
Assertion `(__has_nothrow_constructor(E) && f<E>() && My<E>().f() &&
My2<E>::trait && My3<E>().f())' failed.
FAIL: g++.dg/ext/has_nothrow_constructor.C execution test

has_nothrow_copy.exe: [...]/has_nothrow_copy.C:129: int main(): Assertion
`(__has_nothrow_copy(E) && f<E>() && My<E>().f() && My2<E>::trait &&
My3<E>().f())' failed.
FAIL: g++.dg/ext/has_nothrow_copy.C execution test


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #12 from pcarlini at suse dot de  2008-01-27 11:44 -------
Yes, I noticed. Frankly, I'm not really worried because of the nature of the
tests: the checks can give different answers depending on whether the compiler
is able or not to figure out that a given function cannot throw. For some
reason (which I agree would be interesting to understand in better detail),
-fpic/PIC makes makes more difficult for the compiler to assess that a function
cannot really throw. I'm not sure about the best way to fix that: we could just
zap those specific tests which have such "instability", or condition the result
on -fpic/PIC via macros, or something better. I would probably be tempted to go
the first route, for 4.3.0., at least. 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[rguenth at gcc dot gnu dot org]

------- Comment #13 from rguenth at gcc dot gnu dot org  2008-01-27 12:48 -------
If a function isn't marked nothrow and the function can be overridden by a
shared library (that is, it doesn't bind locally), the compiler cannot derive
such property from its body.

(I didn't look at the tests, but usually marking the affected functions
nothrow or making them bind locally works around this problem).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #14 from pcarlini at suse dot de  2008-01-27 13:34 -------
(In reply to comment #13)
> If a function isn't marked nothrow and the function can be overridden by a
> shared library (that is, it doesn't bind locally), the compiler cannot derive
> such property from its body.

Thanks for the details.

> (I didn't look at the tests, but usually marking the affected functions
> nothrow or making them bind locally works around this problem).

Well, the functions in those specific tests aren't marked no throw on purpose
(we do have other tests for the no throw variants), because I was exactly
testing that in some specific cases the C++ front-end is able to figure out by
itself that the function doesn't really throw. All in all I'm now thinking that
it's good to have such tests, we should only conditionalize the result of the
tests on -fpic/PIC, I suppose we do have a macro for that?!?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #15 from ghazi at gcc dot gnu dot org  2008-01-27 18:39 -------
> All in all I'm now thinking that
> it's good to have such tests, we should only conditionalize the result of the
> tests on -fpic/PIC, I suppose we do have a macro for that?!?

How about binding locally when pic?  E.g.:

#ifdef __PIC__
static
#endif
function_foo()


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #16 from pcarlini at suse dot de  2008-01-27 18:51 -------
Created an attachment (id=15030)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15030&action=view)
Draft idea for the -fpic/-fPIC fails


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #17 from pcarlini at suse dot de  2008-01-27 18:54 -------
Hi Kaveh. One problem I can see is that we are dealing with special member
functions, like constructors and assignment operators. Can you see anything
wrong with the straightforward implementation of idea per the attached
patchlet? If it looks ok to you, it would be matter of doing the same for the
other 2 files...


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #18 from ghazi at gcc dot gnu dot org  2008-01-27 19:54 -------
(In reply to comment #17)
> Hi Kaveh. One problem I can see is that we are dealing with special member
> functions, like constructors and assignment operators

Ah, I guess you can't make those static.

> Can you see anything
> wrong with the straightforward implementation of idea per the attached
> patchlet? If it looks ok to you, it would be matter of doing the same for the
> other 2 files...

It looks like you reversed the checks for the problematic cases when you see
__PIC__.  I wonder whether this will work on darwin which still binds locally
for pic code.
http://gcc.gnu.org/ml/gcc-patches/2008-01/msg00495.html

The regtester might barf on this change, I don't have darwin to check.

If it does, maybe instead you simply nuke the problematic cases when you see
__PIC__.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #19 from ghazi at gcc dot gnu dot org  2008-01-27 20:09 -------
(In reply to comment #18)
> If it does, maybe instead you simply nuke the problematic cases when you see
> __PIC__.

Another option that might work is to add -fpie when we see __PIC__.  That
should work on darwin etc as well.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #20 from pcarlini at suse dot de  2008-01-27 20:40 -------
Hi Kaveh. I just checked darwin and indeed, we have an issue there, which,
AFAICS, is not worked around with -fpie. I say, let's just skip the test when
__PIC__ is defined, and be done with it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #21 from pcarlini at suse dot de  2008-01-27 20:47 -------
Since you are already set for this extended kind of testing, can you run the
new patch? Thanks a lot in advance!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #22 from pcarlini at suse dot de  2008-01-27 20:49 -------
Created an attachment (id=15031)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15031&action=view)
New draft


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #23 from ghazi at gcc dot gnu dot org  2008-01-27 21:09 -------
(In reply to comment #20)
> Hi Kaveh. I just checked darwin and indeed, we have an issue there, which,
> AFAICS, is not worked around with -fpie.

Hmm, did you mean darwin failed with (your patch + -fpie) or just with -fpie
and the original tests?

I meant for just using -fpie on darwin with no other changes.

I have tested a patch that fixes the tests on x86-linux-gnu using -fpie.  If it
works on darwin, then great.  Otherwise I'll go with your option.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #24 from ghazi at gcc dot gnu dot org  2008-01-27 21:10 -------
Patch which works on i686-unknown-linux-gnu:

2008-01-27  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>

        * g++.dg/ext/has_nothrow_assign.C: Add -fpie when __PIC__.
        * g++.dg/ext/has_nothrow_constructor.C: Likewise.
        * g++.dg/ext/has_nothrow_copy.C: Likewise.

diff -rup orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_assign.C
egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_assign.C
--- orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_assign.C
2007-12-31 19:13:13.000000000 +0100
+++ egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_assign.C     
2008-01-27 21:17:32.000000000 +0100
@@ -1,4 +1,5 @@
 // { dg-do "run" }
+// { dg-options "-fpie" { target { ! nonpic } } }
 #include <cassert>

 struct A
diff -rup
orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_constructor.C
egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_const
ructor.C
--- orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_constructor.C   
2007-12-31 19:13:14.000000000 +0100
+++ egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_constructor.C
2008-01-27 21:17:48.000000000 +0100
@@ -1,4 +1,5 @@
 // { dg-do "run" }
+// { dg-options "-fpie" { target { ! nonpic } } }
 #include <cassert>

 struct A
diff -rup orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_copy.C
egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_copy.C
--- orig/egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_copy.C  
2007-12-31 19:13:14.000000000 +0100
+++ egcc-SVN20080126/gcc/testsuite/g++.dg/ext/has_nothrow_copy.C       
2008-01-27 21:17:54.000000000 +0100
@@ -1,4 +1,5 @@
 // { dg-do "run" }
+// { dg-options "-fpie" { target { ! nonpic } } }
 #include <cassert>

 struct A


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #25 from ghazi at gcc dot gnu dot org  2008-01-27 21:17 -------
(In reply to comment #22)
> Created an attachment (id=15031)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15031&action=view) [edit]
> New draft

I tried your latest draft and it fails for has_nothrow_assign.C because of a
typo.  The third #ifndef has no macro so I get:

    has_nothrow_assign.C:149: error: no macro name given in #ifndef directive

When I fix that it works.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #26 from pcarlini at suse dot de  2008-01-27 21:35 -------
(In reply to comment #23)
> I meant for just using -fpie on darwin with no other changes.

The problem I see, on darwin, is that -fpie cannot be passed to the driver,
because eventually, the linker rejects -pie. Is that a know issue, dealt with
automatically by the testing infrastructure? In that case, your patch is great,
otherwise, or if things are going to be tricky, I say let's just go with mine
(sorry about the typo) and spare time for something else ;)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #27 from ghazi at gcc dot gnu dot org  2008-01-27 22:03 -------
(In reply to comment #26)
> (In reply to comment #23)
> > I meant for just using -fpie on darwin with no other changes.
> The problem I see, on darwin, is that -fpie cannot be passed to the driver,
> because eventually, the linker rejects -pie. Is that a know issue, dealt with
> automatically by the testing infrastructure? In that case, your patch is great,

Hmm, there are a couple of other tests using -fpie on darwin:
./g++.dg/parse/attr-externally-visible-1.C:/* { dg-options "-O3 -fwhole-program
-fpie" { target *-*-darwin* } } */
./g++.dg/other/first-global.C:/* { dg-options "-fpie" { target *-*-darwin* } }
*/
./gcc.dg/pie-link.c:/* { dg-options "-fpie" } */


On closer inspection, the first two are compile-only, so the linker isn't
invoked.  The latter is only run on darwin[912], which I assume means darwin9
or later (10, 11, 12, 20, 21, 22, ...).

> otherwise, or if things are going to be tricky, I say let's just go with mine
> (sorry about the typo) and spare time for something else ;)

So I guess you're using an older version of darwin that doesn't know about pie.
 In that case I guess your patch (with the typo fixed) is the best option.

Will you be installing it?

Thanks,
--Kaveh


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[pcarlini at suse dot de]

------- Comment #28 from pcarlini at suse dot de  2008-01-27 22:27 -------
(In reply to comment #27)

> So I guess you're using an older version of darwin that doesn't know about pie.

I'm testing on Darwin 8.11, that is the last Tiger, still pretty common...

>  In that case I guess your patch (with the typo fixed) is the best option.
> 
> Will you be installing it?

Sure. Many thanks for your help!

Paolo.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[ghazi at gcc dot gnu dot org]

------- Comment #29 from ghazi at gcc dot gnu dot org  2009-11-22 17:54 -------
The -fpic/-fPIC failures have been fixed long ago in gcc-4.3.x.

Can we close this bug?


-- 

ghazi at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[paolo dot carlini at oracle dot com]

------- Comment #30 from paolo dot carlini at oracle dot com  2009-11-22 19:13 -------
Nope, let's keep it open as a reminder that we are still missing
__is_convertible_to and the newer ones, needed to implement N2984 (I'm
implementing three as we are speaking)


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2006-02-05 10:22:29         |2009-11-22 19:13:48
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[paolo dot carlini at oracle dot com]

-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |ASSIGNED
   Last reconfirmed|2009-11-22 19:13:48         |2009-11-22 19:13:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

[Bug c++/26099] support for type traits is not available

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

--- Comment #31 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-08-31 17:11:38 UTC ---
__is_convertible_to isn't such a big issue anymore, thanks to Core/1170 (in
C++11 SFINAE includes access control, still unimplemented in GCC, though).
However, we now need front-end support for the is_trivially_* traits.

[Bug c++/26099] support for type traits is not available

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
                 CC|gcc-bugs at gcc dot gnu.org        |
           Assignee|paolo.carlini at oracle dot com    |unassigned at gcc dot gnu.org

[Bug c++/26099] support for type traits is not available

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.0

--- Comment #32 from Paolo Carlini <paolo.carlini at oracle dot com> ---
The __is_trivially_* bits are tracked by c++/63362.

[Bug c++/26099] support for type traits is not available

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26099

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|5.0                         |---