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Running GNAT SAS Again
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As you may have noticed already, GNAT SAS recorded the results of the first run
that you made as the baseline for successive runs after possible code
modifications, as shown by the top line displayed in the GNAT SAS report::

   Base run: sdc.baseline.sam             Current run: sdc.sam

Notice the different kinds of filters which are available on the right side of
the window, in panel Message ranking, in particular the `Message history`
part: selecting these different filters will
show/hide the corresponding messages in the Locations View at the bottom. By
default, only the messages which correspond to the current run (either
**added** or **unchanged**) are shown.

Uncheck the **unchanged** box in Message history. This clears the location
view from all previously reported messages.

Now check the **removed** box: if `--show age+removed` is used, you will see all
the messages which have disappeared since the base run (the first run in this
case).

GNAT SAS defines two types of runs: regular and baseline. The runs are represented
by `sam` files. A first GNAT SAS
run is a baseline run and it results in a sam file `<PROJECT_NAME>.baseline.sam`.
All the subsequent runs are regular runs resulting in sam file `<PROJECT_NAME>.sam`
and are compared to the baseline run.


In order to bump a baseline to a current run, you can use the menu
:menuselection:`GNATSAS --> Baseline --> Bump Baseline to Current Run`. You can also
set a baseline to a given run via :menuselection:`GNATSAS --> Baseline --> Set Baseline to Run...`.