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Re: 19990924: nc_inq_var of netcdf

>To: address@hidden
>From: address@hidden
>Subject: nc_inq_var of netcdf
>Organization: .
>Keywords: Borland, nc_type, enum versus int

------- Forwarded Message

Date:    Fri, 08 Oct 1999 16:45:04 +0200
From:    address@hidden
To:      address@hidden
Subject: RE: Re: 19990924: nc_inq_var of netcdf

Russ,
in the meantime I even found a better solution. I surround the header file 
with the following pragmas:
#pragma option push -b      // Treat Enums As Ints (does not work as 
compiler option)
    #include "netcdf.h"
#pragma option pop
This instructs the Borland compiler to treat Enums as integer; then 
everything works fine.
Yes, compiling from source code would also have solved the problem.
Best regards and have a nice weekend
Thomas

- -----Original Message-----
From: address@hidden [mailto:address@hidden]
Sent: Friday, October 08, 1999 16:24
To: THOMAS DIETRICH
Subject: Re: 19990924: nc_inq_var of netcdf


>To: address@hidden
>From: address@hidden
>Subject: nc_inq_var of netcdf
>Organization: .
>Keywords: 199909241257.GAA06898

Thomas,

> sorry that I didn't answer earlier; I was caught by other problems.
> Thank you for your detailed answer.
> Just for your information:
> nc_type is an enum; Borland reserves only one byte for it but your 
library 
> assumes an integer.
> Therefore your function returns an integer where there is only one byte 
on 
> the stack; this overwrites varId because its address happens to be on 
the 
> stack near the address of the type variable.
> I could not convince the Borland compiler (bcc32.exe) to use an integer 
> size for the enum (despite the -b switch should do it and is on by 
> default).
> Therefore my solution is using an integer directly and casting this to 
the 
> nc_type:
>     int     type; //nc_type type;
> ...
>     err = nc_inq_var( cdfId,
>                       varId,
>                       NULL,     // name
>                       (nc_type *)&type,
>                       &dims,
>                       NULL,     // dimids
>                       NULL );   // natts
> This leaves varId unchanged.

Thanks for sending back your diagnosis of the problem.

But our library does not assume nc_type is an integer.  As far as I
can determine, it is declared with the typedef nc_type everywhere it
is used in the library source code, so it is treated consistently as
an enum (if you can find where it's treated as an int, pleas let me
know, that's a bug!).  However, whatever compiler was used to create
the DLL version of the library you are using (MS Visual C++?) may have
implemented enum as an integer.

Therefor I think the problem is an incompatibility between the
compiled DLL you are using and the Borland compiling environment you
have set up.  If you compiled the library from source with the same
compiler and flags you are using for the program that calls the
library, I would guess that you would not have to use this casting
trick, but it would work as intended.

- --Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



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