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modelica / ModelicaStandardLibrary

Free (standard conforming) library to model mechanical (1D/3D), electrical (analog, digital, machines), magnetic, thermal, fluid, control systems and hierarchical state machines. Also numerical functions and functions for strings, files and streams are included.
https://doc.modelica.org
BSD 3-Clause "New" or "Revised" License
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Over-zealous null-pointer guards in ModelicaStandardTables_CombiTimeTable_init (etc) #4185

Open HansOlsson opened 1 year ago

HansOlsson commented 1 year ago

If you look at the declaration of ModelicaStandardTables_CombiTimeTable_init (and similar ones) you notice that all pointer arguments are declared to be non-NULL (using nonnull-attribute for Gcc and SAL for Visual Studio).

However, if the table is read from a file then table isn't used (or even checked) and can safely be NULL.

The correction for Gcc will be a bit messy (specify all non-NULL pointers) so I didn't want to make the PR unless it is likely to be accepted.

beutlich commented 1 year ago

Even if the table is read from file, it still gets passed as non-null double* pointer if called from a Modelica environment. Having a Modelica environment was the initial assumption though. If called from a non-Modelica environment, well, it can be different and table can be null if it should be read from file.

HansOlsson commented 1 year ago

Even if the table is read from file, it still gets passed as non-null double* pointer if called from a Modelica environment. Having a Modelica environment was the initial assumption though. If called from a non-Modelica environment, well, it can be different and table can be null if it should be read from file.

I assume you mean "Modelica environment" as short for "Modelica Standard Library environment", since we have some that use the C-sources directly in their Modelica code - bypassing/copying the MSL models. (In particular that's how it was found.)

beutlich commented 1 year ago

By "Modelica env" I meant a Modelica simulation environment as Dymola or SimulationX. In Modelica Language it is not possible to pass a null pointer to an external function or external object ctor.

beutlich commented 8 months ago

An idea would be to have two different ctors of the external table objects - one for construction of table from file and other for construction from passed array.