[Opengrads-devel] Fwd: the build environment

[Jennifer A. <jm...@co...>]

I think the opengrads-devel list needs a "Reply-To:" header when it  
sends out messages. I sent the following as a 'reply' but it only  
went to Arlindo...
--Jennifer


Begin forwarded message:

From: Jennifer Adams <jm...@co...>
Date: May 14, 2008 11:47:36 AM EDT
To: Arlindo da Silva <da...@al...>
Subject: Re: [Opengrads-devel] the build environment


On May 12, 2008, at 11:29 PM, Arlindo da Silva wrote:

> On Mon, May 12, 2008 at 6:26 PM, Jennifer Adams <jm...@co...>  
> wrote:
>>
>> for v1.9 and more recently adapted it for v2. We don't claim that  
>> what is on the OpenGrADS repo is perfect but it is a pretty good  
>> start.  Some of the small changes we made to the v2 codebase were  
>> made to support the new build, and to fix some potentially hard to  
>> find bugs (for example, "grads.h" no longer includes "netcdf.h").
> Why is that a bug?
>
> The problem is that both "grads" and "gradsdap" link against the  
> same "grads.o". So, you end up linking "gradsdap" with something  
> that was compiled with the wrong "netcdf.h" (the one from the  
> NetCDF library, rather than the one from nc-dap). Since both  
> versions of "netcdf.h" currently in use are very similar, I have no  
> evidence that your v2 build has a problem. However, we've been  
> bitten by this netcdf.h mismatch issue several times in the past  
> that it pays to play it save.

Why should grads.o be different for grads and gradsdap? There are no  
netcdf dependent calls in there. All the netcdf library calls are in  
gasdf.c, gaio.c and gauser.c -- these three files have:
#include netcdf.h
and have separate .o files when linking grads and gradsdap. The  
other .o files that are separated for the two executables are gaddes  
and gacfg because there are some netcdf dependencies there but no  
calls to the library.

Jennifer