gnuplot-beta

Compile problem on Mac OS X 10.4/gcc 4.0

[Per P. <per...@ma...>]

Hi,
I've had a report that gnuplot won't compile on OS X 10.4 and gcc 4.0 
because of a conflict with a static char array "Class" in gplt_x11.c 
and the Objective-C type "Class". It has not been a problem before so 
it seems gcc 4 is pickier about this than gcc 3.x.

I haven't upgraded to 10.4 yet, but I thought that I could be 
"pro-active" and fix it anyway...

When detecting Mac OS X and libaquaterm "-ObjC" is added to CFLAGS 
(apple.m4), and every file is compiled as ObjC although only 
aquaterm.trm needs the "-ObjC" flag.
As I see it, there are two ways to fix this:
1) Change the name "Class" in gplt_x11.c
2) Increase granularity in buildsystem to only compile aquaterm.trm (or 
term.c) with "-ObjC"

Obviously, (2) is the right thing to do, but I have to confess that I 
don't understand how to properly change the build system to achieve 
that. Suggestions would be appreciated.

/Per

Re: Compile problem on Mac OS X 10.4/gcc 4.0

[Hans-Bernhard B. <br...@ph...>]

Per Persson wrote:
> I've had a report that gnuplot won't compile on OS X 10.4 and gcc 4.0 
> because of a conflict with a static char array "Class" in gplt_x11.c and 
> the Objective-C type "Class". It has not been a problem before so it 
> seems gcc 4 is pickier about this than gcc 3.x.

Or maybe it's plain wrong about it.  Stranger bugs have crept into 
little-used corners of GCC before.

> When detecting Mac OS X and libaquaterm "-ObjC" is added to CFLAGS 
> (apple.m4), and every file is compiled as ObjC although only 
> aquaterm.trm needs the "-ObjC" flag.
> As I see it, there are two ways to fix this:
> 1) Change the name "Class" in gplt_x11.c
> 2) Increase granularity in buildsystem to only compile aquaterm.trm (or 
> term.c) with "-ObjC"

I'm not convinced that (2) can work.  -ObjC effectively switches to a 
different language, with possibly different calling conventions and name 
mangling rules.  I wouldn't be surprised in any way if this broke the
link completely.

Re: Compile problem on Mac OS X 10.4/gcc 4.0

[Per P. <per...@ma...>]

On May 8, 2005, at 18:47, Hans-Bernhard Broeker wrote:

> Per Persson wrote:
>> I've had a report that gnuplot won't compile on OS X 10.4 and gcc 4.0 
>> because of a conflict with a static char array "Class" in gplt_x11.c 
>> and the Objective-C type "Class". It has not been a problem before so 
>> it seems gcc 4 is pickier about this than gcc 3.x.
>
> Or maybe it's plain wrong about it.  Stranger bugs have crept into 
> little-used corners of GCC before.

Agreed.

>
>> When detecting Mac OS X and libaquaterm "-ObjC" is added to CFLAGS 
>> (apple.m4), and every file is compiled as ObjC although only 
>> aquaterm.trm needs the "-ObjC" flag.
>> As I see it, there are two ways to fix this:
>> 1) Change the name "Class" in gplt_x11.c
>> 2) Increase granularity in buildsystem to only compile aquaterm.trm 
>> (or term.c) with "-ObjC"
>
> I'm not convinced that (2) can work.  -ObjC effectively switches to a 
> different language, with possibly different calling conventions and 
> name mangling rules.

ObjC is a strict superset of C, in the sense that any C (well make that 
C89 or whatever) code *should* compile using the ObjC compiler. There 
is no C++ style name mangling going on in ObjC. It is common practice 
to mix C and ObjC using each where it is best suited.

> I wouldn't be surprised in any way if this broke the
> link completely.

Not a linker issue, it is the compiler complaining...
The following is from a bugreport to DarwinPorts (package manager) list:

> if gcc -DHAVE_CONFIG_H -I. -I. -I..  -I../term -I../term 
> -DBINDIR=\"/opt/local/bin\" -
> DX11_DRIVER_DIR=\"/opt/local/libexec/gnuplot/4.0\" -DCONTACT=\"gnuplot-
> bugs at lists.sourceforge.net\" 
> -DHELPFILE=\"/opt/local/share/gnuplot/4.0/gnuplot.gih\" -I/opt/local/
> include -no-cpp-precomp  -I/usr/X11R6/include -I/opt/local/include 
> -I/opt/local/include  -g -O2 -
> ObjC -MT gplt_x11.o -MD -MP -MF ".deps/gplt_x11.Tpo" \
>   -c -o gplt_x11.o `test -f 'gplt_x11.c' || echo './'`gplt_x11.c; \
> then mv ".deps/gplt_x11.Tpo" ".deps/gplt_x11.Po"; \
> else rm -f ".deps/gplt_x11.Tpo"; exit 1; \
> fi
> gplt_x11.c:519: error: 'Class' redeclared as different kind of symbol
> <built-in>:0: error: previous declaration of 'Class' was here
> make[3]: *** [gplt_x11.o] Error 1
> make[2]: *** [all-recursive] Error 1
> make[1]: *** [all-recursive] Error 1
> make: *** [all] Error 2

As I said, until I get 10.4 installed I really can't explore this 
further. Still, I think that (2) would be nice to implement some time 
from a pure cleanlyness perpspective...

/Per

Re: Compile problem on Mac OS X 10.4/gcc 4.0

[Ethan M. <merritt@u.washington.edu>]

On Sunday 08 May 2005 05:23 am, Per Persson wrote:
> When detecting Mac OS X and libaquaterm "-ObjC" is added to CFLAGS
> (apple.m4), and every file is compiled as ObjC although only
> aquaterm.trm needs the "-ObjC" flag.
> As I see it, there are two ways to fix this:
> 1) Change the name "Class" in gplt_x11.c
> 2) Increase granularity in buildsystem to only compile aquaterm.trm (or
> term.c) with "-ObjC"

(3) Clean up aquaterm.trm so that it compiles without the -ObjC flag

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington 98195-7742

Re: Compile problem on Mac OS X 10.4/gcc 4.0

[<br...@ph...>]

Ethan Merritt wrote:
>>1) Change the name "Class" in gplt_x11.c
>>2) Increase granularity in buildsystem to only compile aquaterm.trm (or
>>term.c) with "-ObjC"
> (3) Clean up aquaterm.trm so that it compiles without the -ObjC flag

(4) rename that thing in gplt_x11.c from "Class" to something else.

Re: Compile problem on Mac OS X 10.4/gcc 4.0

[Ethan M. <merritt@u.washington.edu>]

On Monday 09 May 2005 04:36 am, Hans-Bernhard Br=F6ker wrote:
> Ethan Merritt wrote:
> >>1) Change the name "Class" in gplt_x11.c
> >>2) Increase granularity in buildsystem to only compile aquaterm.trm (or
> >>term.c) with "-ObjC"
> > (3) Clean up aquaterm.trm so that it compiles without the -ObjC flag
>=20
> (4) rename that thing in gplt_x11.c from "Class" to something else.=20

I thought that was already suggestion (1)?

=46ine with me.  I'll do it.

But I'm still rather uneasy about compiling the whole source tree
with -ObjC just because the one terminal driver wants it.

=2D-=20
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195