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* [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name
@ 2004-10-20 12:47 fafa at freesurf dot ch
2004-10-20 13:06 ` [Bug c++/18077] [3.3/3.4/4.0 Regression] " pinskia at gcc dot gnu dot org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: fafa at freesurf dot ch @ 2004-10-20 12:47 UTC (permalink / raw)
To: gcc-bugs
Members of anonymous namespaces should get a name that is mangled in a way so
as to make them unique. This is not the case if a global variable is defined
before the keyword "namespace" is used. In that case the first global variable
name is used for the name mangling. If I then link with "-z muldefs" I get
wrong symbol resolution.
Example:
foo1.cpp:
#include <stdio.h>
int iii;
namespace {
void f() { printf("foo1\n"); }
}
void foo1() { f(); }
foo2.cpp:
#include <stdio.h>
int iii;
namespace {
void f() { printf("foo2\n"); }
}
void foo2() { f(); }
main.cpp:
extern void foo1();
extern void foo2();
int main() {
foo1();
foo2();
return 0;
}
g++ -o foo foo1.cpp foo2.cpp main.cpp -z muldefs
./foo
generates the output
foo1
foo1
instead of
foo1
foo2
because both mangled names for the functions f are "_ZN14_GLOBAL__N_iii1fEv",
and the linker chosses one of the two for both calls.
The error vanishes if I just write
namespace {}
before the definition of iii, because then the mangled name of f changes
to "_ZN25_GLOBAL__N_foo1.cppgmEtmb1fEv" which seems the correct name to me.
--
Summary: Members of anonymous namespaces get name mangled with
first global variable instead of file name
Product: gcc
Version: 3.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: fafa at freesurf dot ch
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18077
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/18077] [3.3/3.4/4.0 Regression] Members of anonymous namespaces get name mangled with first global variable instead of file name
2004-10-20 12:47 [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name fafa at freesurf dot ch
@ 2004-10-20 13:06 ` pinskia at gcc dot gnu dot org
2004-10-28 6:04 ` mmitchel at gcc dot gnu dot org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-10-20 13:06 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-10-20 13:05 -------
Confirmed, a regression from 3.0.4.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Keywords| |wrong-code
Known to fail| |3.3.3 3.4.0 4.0.0
Known to work| |3.0.4
Last reconfirmed|0000-00-00 00:00:00 |2004-10-20 13:05:57
date| |
Summary|Members of anonymous |[3.3/3.4/4.0 Regression]
|namespaces get name mangled |Members of anonymous
|with first global variable |namespaces get name mangled
|instead of file name |with first global variable
| |instead of file name
Target Milestone|--- |3.4.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18077
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/18077] [3.3/3.4/4.0 Regression] Members of anonymous namespaces get name mangled with first global variable instead of file name
2004-10-20 12:47 [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name fafa at freesurf dot ch
2004-10-20 13:06 ` [Bug c++/18077] [3.3/3.4/4.0 Regression] " pinskia at gcc dot gnu dot org
@ 2004-10-28 6:04 ` mmitchel at gcc dot gnu dot org
2004-10-28 17:27 ` fafa at freesurf dot ch
2004-11-02 7:22 ` bugzilla at familie-koegl dot de
3 siblings, 0 replies; 5+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2004-10-28 6:04 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From mmitchel at gcc dot gnu dot org 2004-10-28 06:04 -------
Using -z muldefs is beyond the scope of the C++ standard.
There is no way to win for everyone here; some people really do not want the
random names because they want predictability from the compiler.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18077
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/18077] [3.3/3.4/4.0 Regression] Members of anonymous namespaces get name mangled with first global variable instead of file name
2004-10-20 12:47 [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name fafa at freesurf dot ch
2004-10-20 13:06 ` [Bug c++/18077] [3.3/3.4/4.0 Regression] " pinskia at gcc dot gnu dot org
2004-10-28 6:04 ` mmitchel at gcc dot gnu dot org
@ 2004-10-28 17:27 ` fafa at freesurf dot ch
2004-11-02 7:22 ` bugzilla at familie-koegl dot de
3 siblings, 0 replies; 5+ messages in thread
From: fafa at freesurf dot ch @ 2004-10-28 17:27 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From fafa at freesurf dot ch 2004-10-28 17:27 -------
(In reply to comment #2)
> Using -z muldefs is beyond the scope of the C++ standard.
>
> There is no way to win for everyone here; some people really do not want the
> random names because they want predictability from the compiler.
If the name of a symbol depends on the order of definition of variables which
have nothing to do with this symbol, it's just as "random". And if I use the
unnamed namespace first, I get what you call "random name" anyway. Is this
predictable ?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18077
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/18077] [3.3/3.4/4.0 Regression] Members of anonymous namespaces get name mangled with first global variable instead of file name
2004-10-20 12:47 [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name fafa at freesurf dot ch
` (2 preceding siblings ...)
2004-10-28 17:27 ` fafa at freesurf dot ch
@ 2004-11-02 7:22 ` bugzilla at familie-koegl dot de
3 siblings, 0 replies; 5+ messages in thread
From: bugzilla at familie-koegl dot de @ 2004-11-02 7:22 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From bugzilla at familie-koegl dot de 2004-11-02 07:22 -------
(In reply to comment #2)
> Using -z muldefs is beyond the scope of the C++ standard.
> There is no way to win for everyone here; some people really do not want the
> random names because they want predictability from the compiler.
Yeah, and that's exactly why I would have expected the <= 3.0.4 behavior: the
randomness in names results from later GCC's incorporating the name of the
first global symbol in the symbol names of the unnamed namespace entities. I
really don't see how the new behavior is less random or more predictable.
Especially when one can switch back to the old behavior by including a file
containing nothing but 'namespace {}' via -include. So what was the rationale
for having changed the behavior at all?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18077
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2004-11-02 7:22 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2004-10-20 12:47 [Bug c++/18077] New: Members of anonymous namespaces get name mangled with first global variable instead of file name fafa at freesurf dot ch
2004-10-20 13:06 ` [Bug c++/18077] [3.3/3.4/4.0 Regression] " pinskia at gcc dot gnu dot org
2004-10-28 6:04 ` mmitchel at gcc dot gnu dot org
2004-10-28 17:27 ` fafa at freesurf dot ch
2004-11-02 7:22 ` bugzilla at familie-koegl dot de
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