[Bug c++/22252] New: pragma interface/implementation still break synthesized methods

[Bug c++/22252] New: pragma interface/implementation still break synthesized methods

[matz at suse dot de]

This is similar to bug 21280, but it is _not_ fixed by the patches therein. 
In fact it still happens with current 4.0 branch as of 2005-06-30. 
 
Compile these files: 
 
% cat a.h 
#include <vector> 
#pragma interface 
struct A { 
  std::vector<char> vc; 
}; 
% cat use.cc 
#include "a.h" 
A a; 
int main() {} 
% cat a.cc 
#include <vector> 
#pragma implementation 
#include "a.h" 
 
% g++ -W -Wall -O2 a.cc use.cc  
a.h:3: warning: inline function &#8216;A::A()&#8217; used but never defined 
a.h:3: warning: inline function &#8216;A::~A()&#8217; used but never defined 
/tmp/ccuIwMBN.o: In function `__static_initialization_and_destruction_0(int, 
int)': 
use.cc:(.text+0x31): undefined reference to `A::A()' 
collect2: ld returned 1 exit status 
 
This is because A::A() is not synthesized, although it should happen in file 
a.cc (which contains the pragma implementation). 
 
So, something still is wrong (this actually breaks building lyx btw.) after 
21280 was fixed.

-- 
           Summary: pragma interface/implementation still break synthesized
                    methods
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: matz at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org,schwab at suse dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
            Summary|pragma                      |[4.0/4.1 Regression] pragma
                   |interface/implementation    |interface/implementation
                   |still break synthesized     |still break synthesized
                   |methods                     |methods
   Target Milestone|---                         |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[matz at suse dot de]

------- Additional Comments From matz at suse dot de  2005-06-30 15:01 -------
Andrew: that's not a diagnostic issue.  While the diagnostic (the warning) 
indeed is wrong and misleading (and probably points to the underlying cause 
of this issue), the actual error I'm complaining about is 
the link error, due to not emitting an out-of-line copy of A::A() in a.cc as 
it would be required. 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-30 15:10 -------
(In reply to comment #1)
Yes which is why I did not confirm it yet because I did not look at fully.  I just added the diagnostic 
keyword because it is still a wrong warning.  I am adding wrong-code also.
Reduced testcase:
---- a.ii ----
# 1 "a.cc"
# 0 "<built-in>"
# 1 "<command line>"
# 1 "a.cc"
#pragma implementation
# 1 "a.h" 1
struct B
{
  B(){};
  ~B(){}
};
#pragma interface
struct A {
  B a;

};
# 3 "a.cc" 2

---- use.ii ----
# 1 "use.cc"
# 0 "<built-in>"
# 1 "<command line>"
# 1 "use.cc"
# 1 "a.h" 1
struct B
{
  B(){};
  ~B(){}
};
#pragma interface
struct A {
  B a;

};
# 2 "use.cc" 2
A a;
int main() {}

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-30 15:10:43
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[matz at suse dot de]

------- Additional Comments From matz at suse dot de  2005-06-30 15:23 -------
Ah, I see.  Note that you must compile the reduced testcase (thanks for 
that) with -O0, or with -fno-inline, otherwise the A::A ctor will be inlined 
in use.cc (making the warning about the non-availability of it even more 
funny ;-) ), and not lead to the link error. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[mmitchel at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |mark at codesourcery dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0 Regression] pragma interface/implementation still break synthesized methods

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2005-09-09 16:33 -------
Fixed in 4.1.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.0/4.1 Regression] pragma |[4.0 Regression] pragma
                   |interface/implementation    |interface/implementation
                   |still break synthesized     |still break synthesized
                   |methods                     |methods


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0 Regression] pragma interface/implementation still break synthesized methods

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-09 18:56 -------
Subject: Bug 22252

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	mmitchel@gcc.gnu.org	2005-09-09 18:56:16

Modified files:
	gcc/testsuite  : ChangeLog 
	gcc/cp         : ChangeLog decl.c decl2.c pt.c semantics.c 
Added files:
	gcc/testsuite/g++.dg/ext: interface1.C interface1.h 
	                          interface1a.cc 

Log message:
	PR c++/22252
	* decl.c (start_preparsed_function): Do not pay attention to
	#pragma interface for implicitly-defined methods.
	* decl2.c (cp_finish_file): Do not complain about uses of inline
	functions that have bodies, even if we decided not to emit the
	body in this translation unit.
	* semantics.c (note_decl_for_pch): Do not mess with linkage.
	(expand_or_defer_fn): Make inline, non-template functions COMDAT
	at this point.
	
	PR c++/22252
	* g++.dg/ext/interface1.C: New test.
	* g++.dg/ext/interface1.h: Likewise.
	* g++.dg/ext/interface1a.cc: Likewise.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.6041&r2=1.6042
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4880&r2=1.4881
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/decl.c.diff?cvsroot=gcc&r1=1.1424&r2=1.1425
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/decl2.c.diff?cvsroot=gcc&r1=1.799&r2=1.800
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&r1=1.1029&r2=1.1030
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/semantics.c.diff?cvsroot=gcc&r1=1.487&r2=1.488
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/ext/interface1.C.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/ext/interface1.h.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/ext/interface1a.cc.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0 Regression] pragma interface/implementation still break synthesized methods

[mmitchel at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.2                       |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252

[Bug c++/22252] [4.0/4.1 Regression] pragma interface/implementation still break synthesized methods

[mmitchel at gcc dot gnu dot org]

------- Comment #10 from mmitchel at gcc dot gnu dot org  2006-01-15 22:43 -------
The claim in Comment #9 is that this is a 4.1 regression as well as a 4.0
regression, so I've udpated the subject line.  It would be interesting to know
if this affects mainline as well.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.0 Regression] pragma     |[4.0/4.1 Regression] pragma
                   |interface/implementation    |interface/implementation
                   |still break synthesized     |still break synthesized
                   |methods                     |methods


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22252