Re: osiWireFormat.h problems

[Eric Norum <norume@aps.anl.gov>]

On Dec 4, 2006, at 12:52 PM, Jeff Hill wrote:

> Eric,
>
> It would easier from my end if I could see the compiler errors before
> changes were made.
Those were in my original message:
====================================================================
I did a CVS update this morning and can no longer build base:

/usr/local/rtems/rtems-4.7/bin/m68k-rtems4.7-g++ -B/usr/local/rtems/ 
rtems-4.7/m68k-rtems4.7/uC5282/lib/ -specs bsp_specs -qrtems   -c   - 
m528x               -DUNIX    -ansi  -O4 -g -g  -Wall      - 
DMY_DO_BOOTP=NULL    - 
DRTEMS_NETWORK_CONFIG_DNS_DOMAINNAME=aps.anl.gov - 
DRTEMS_NETWORK_CONFIG_DNS_DOMAINNAME=aps.anl.gov  -I. -I.. -I../../../ 
include/os/RTEMS -I../../../include         ../casw.cpp
../../../include/osiWireFormat.h: In function 'void AlignedWireGet 
(const T&, T&) [with T = short unsigned int]':
../../../include/osiWireFormat.h:109:   instantiated from  
'AlignedWireRef<const T>::operator T() const [with T = short unsigned  
int]'
../casw.cpp:154:   instantiated from here
../../../include/osiWireFormat.h:230: error: 'tmp' has incomplete type
../../../include/osiWireFormat.h:230: error: storage size of 'tmp'  
isn't known
make[3]: *** [casw.o] Error 1
make[2]: *** [install.RTEMS-uC5282] Error 2
make[1]: *** [ca.install] Error 2
make: *** [src.install] Error 2



norume@gnarly 224> /usr/local/rtems/rtems-4.7/bin/m68k-rtems4.7-g++ -- 
version
m68k-rtems4.7-g++ (GCC) 4.1.1
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There  
is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR  
PURPOSE.
====================================================================

> Are you providing a new RTEMS specific osdWireFormat.h instead of  
> just using
> the one found in osi/os/default?
I'm just using the one in osi/os/default.

> It is also possible that you are seeing a
> warning that the osdWireFormat.h header file couldn't be found?
No.  The above is the entire output error message.


> That might
> be because the RTEMS specific gnu make "vpath" configuration for  
> the libCom
> build does not allow osdWireFormat.h to be installed from the osi/ 
> os/default
> directory? It seems that that one of the above circumstances would be
> necessary for you to see these errors.
>
> Another possibility might be that your woes are specific to GCC 4.0  
> which is
> difficult to test as they have not installed it on any Linux system  
> here and
> you can't get gcc 4.0 at this time for cygwin. It doesn't seem to be
> particularly likely that there would be problems with gcc 4.0 however
> because the code involved looks quite standard and has compiled on  
> many
> compilers.
My OS X machines use gcc 4.0.1:
norume@ctlstrmvid0 18> g++ --version
powerpc-apple-darwin8-g++-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc.  
build 5363)
Copyright (C) 2005 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There  
is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR  
PURPOSE.
The RTEMS compiler is gcc-4.1.1 (as shown in my original message).

> The gory details go like this. The WireAlias template is only  
> needed for the
> primitive types where the byte swap can be done as an alias of an  
> unsigned
> type {epicsInt8, epicsInt16, epicsInt32, epicsFloat32}. Closer  
> inspection
> reveals that the WireAlias template is used only by the following  
> template
> functions which assume that the byte swap can be done as an  
> unsigned alias.
> Where that default assumption does not work, explicit versions of  
> these
> template functions (ordinary functions with the same callable  
> interface as
> the template functions) are provided in osdWireFormat.h for the  
> appropriate
> types where there might be architecture specific issues {epicsUInt16,
> epicsUInt32, epicsFloat64, epicsOldString}. Because the explicit  
> versions of
> these functions do not use the WireAlias template then the explicitly
> implemented types need not be supplied for the WireAlias template.
>
> template < class T >
> inline void WireGet ( const epicsUInt8 * pWireSrc, T & dst );
>
> template < class T >
> inline void WireSet ( const T & src, epicsUInt8 * pWireDst )
>
> template < class T >
> inline void AlignedWireGet ( const T & src, T & dst );
>
> template < class T >
> inline void AlignedWireSet ( const T & src, T & dst );
>
> Furthermore, note that if the explicit function definitions are  
> properly
> provided in osdWireFormat.h then it does not hurt to define the  
> additional
> WireAlias types, but this shouldn't be done because it certainly  
> adds unused
> source code and it also makes catching explicit function  
> definitions missing
> from an OS specific osdWireFormat.h less likely at compile time.
>
> I will give you a call later today.
--
Eric Norum <norume@aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793