[Bug libc/2633] New: _GLIBCPP_USE_NAMESPACES issues

[Bug libc/2633] New: _GLIBCPP_USE_NAMESPACES issues

[marc dot glisse at normalesup dot org]

Hello,
I tried to define the _GLIBCPP_USE_NAMESPACES macro for c++ and hit several
problems. Here are some of them (I should have taken notes...).

In stdio.h, there is "typedef struct _IO_FILE FILE;" in namespace std, but
struct _IO_FILE has not been declared yet so the compiler assumes it is in
namespace std and later refuses to convert stdout to a std::FILE*. It would be
sufficient to declare _IO_FILE (in the global namespace) before this typedef.

pthread.h declares __jmp_buf_tag in the global namespace but setjmp.h declares
it in namespace std. This means the declarations for __sigsetjmp that follow
don't match.

locale.h: I believe __BEGIN_NAMESPACE_STD could be moved before the definition
of struct lconv.

In wchar.h, I can read there is a workaround for gcc stddef.h that puts wint_t
in the global namespace, but if I modify stddef.h to put wint_t in namespace std
and define _WINT_T, the functions declared in namespace __c99 or in the global
namespace have trouble with wint_t not being visible.

wchar.h: the declaration of struct tm looks like this:
__BEGIN_NAMESPACE_STD
struct tm;
__USING_NAMESPACE_STD(tm)
__END_NAMESPACE_STD
My guess is that the last 2 lines are in the wrong order.
Functions like wcscpy, wcscat or wcscmp should be in namespace std, not __c99.

I almost started my tests by replacing __c99 by std in sys/cdefs.h to remove
some errors. I was surprised to see __c99 was not made a subnamespace of std
(and there is no using namespace std in __c99), but I guess there are reasons.

-- 
           Summary: _GLIBCPP_USE_NAMESPACES issues
           Product: glibc
           Version: 2.4
            Status: NEW
          Severity: minor
          Priority: P3
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: marc dot glisse at normalesup dot org
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=2633

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[Bug libc/2633] _GLIBCPP_USE_NAMESPACES issues

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-02-17 18:43 -------
I've fixed a number of things.  Most of the wchar.h changes you request I did
not do.  You have to provide concrete evidence that what you describe is a real
problem on a modern system and that it is required.  Reopen the bug in case you
want to provide the information.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=2633

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[Bug libc/2633] _GLIBCPP_USE_NAMESPACES issues

[marc dot glisse at normalesup dot org]

------- Additional Comments From marc dot glisse at normalesup dot org  2007-02-19 17:09 -------
Thank you for the fixes. About wchar.h, the c++ standard, in the description of
cwchar, talks about wcscpy, wcsncpy, wcscat, etc, which means that they should
be in namespace std, while namespace c99 is for functions like wcstoll if I
understand the rational behind namespaces in glibc correctly.

Minor: for wint_t, the wchar.h header works if stddef.h has a typedef of wint_t
in the global namespace, but not if it only has such a typedef in the std
namespace (then it fails as early as __mbstate_t) as might be logical (but that
is not such a big issue, it simply forces an ugly "using std::wint_t;" in the
global namespace in stddef.h)

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://sourceware.org/bugzilla/show_bug.cgi?id=2633

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[Bug libc/2633] _GLIBCPP_USE_NAMESPACES issues

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-10-07 20:30 -------
I changed the wchar.h header.  The wint_t issue is in the stddef.h file which
comes from gcc.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=2633

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