Re: [netcdfgroup] ncgen bug

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Re: [netcdfgroup] ncgen bug
• From: Dave Allured - NOAA Affiliate <dave.allured@xxxxxxxx>
• Date: Mon, 16 Dec 2019 20:30:08 -0700

This problem is reproducible in netcdf-c 4.7.3 on both Mac OS and Linux.
In particular it occurs in the standard netcdf "make check", but is not
properly reported, due to a bug in the test suite.  Please see github issue
#1576 <https://github.com/Unidata/netcdf-c/issues/1576>.

Notice that in 4.7.3, ncgen behavior changed from an assertion failure, to
a more controlled single message.  This new message points specifically to
a problem with defining enum data values inside a compound type.

    lt-ncgen: tmp1.cdl line 53: Enumconstant associated with a non-econst
type

I am unsure whether the CDL is correct.  This could be either a real ncgen
bug, or incorrect CDL from two different sources.


On Sat, Dec 14, 2019 at 10:52 AM Remik Ziemlinski <remik@xxxxxxxxxxxx>
wrote:

> I get a crash with these steps on macos with Homebrew netcdf:
>
> $ which ncgen
> /usr/local/bin/ncgen
>
> $ ncgen -h
> netcdf library version 4.6.3 of Oct  1 2019 15:44:39 $
>
> $ cat > bug.cdl << EOF
> netcdf bug {
> types:
>    int enum enum1 {A = -1, B = 0, C = 1} ;
>    compound comp1 {
>      enum1 e1;
>    };
>
> dimensions:
>    dim1 = 2 ;
> variables:
>    enum1 var1(dim1) ;
>    comp1 var2(dim1) ;
> data:
>    var1 = A, A ;
>    var2 = {A}, {A} ;
> }
> EOF
>
> $ ncgen -k nc4 -o bug.nc bug.cdl
> assertion failure: econst->subclass == NC_ECONST
>
> Abort trap: 6
>
> Another user reported this on centos with netcdf4.7
> (https://gitlab.com/remikz/nccmp/issues/10)
>
> I do not get this problem when using netcdf 4.6.3 built from scratch on
> Ubuntu 16.04.3 LTS with GCC 5.4.0-6ubuntu1~16.04.12.
>
> Remik
>

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