****************
Analyzing Code
****************

.. container:: PRELUDE BEGIN

.. container:: PRELUDE ROLES

.. role:: ada(code)
    :language: Ada

.. role:: C(code)
    :language: C

.. role:: cpp(code)
    :language: C++

.. role:: rust(code)
    :language: Rust

.. container:: PRELUDE SYMBOLS

.. |rightarrow| replace:: :math:`\rightarrow`
.. |forall| replace:: :math:`\forall`
.. |exists| replace:: :math:`\exists`
.. |equivalent| replace:: :math:`\iff`
.. |le| replace:: :math:`\le`
.. |ge| replace:: :math:`\ge`
.. |lt| replace:: :math:`<`
.. |gt| replace:: :math:`>`
.. |checkmark| replace:: :math:`\checkmark`

.. container:: PRELUDE END

==================
Running GNAT SAS
==================

----------------------
Running the Analysis
----------------------

When running the analysis, the tool maintains data files to store messages, including history and user reviews

  :dfn:`SAM file`
    *Static Analysis Messages* file containing messages generated by analysis engines

  :dfn:`SAR file`
    *Static Analysis Review* file containing user-specified message reviews

-------------------------------
Running From the Command Line
-------------------------------

+ This command only performs the analysis (typically used for simple testing or automation)

  :command:`gnatsas analyze -Psdc`

+ To view results of analysis, you need to generate a report

  :command:`gnatsas report -Psdc`

  + More information in next section

----------------------
Running From the GUI
----------------------

+ From :toolname:`GNAT Studio`

  :menu:`GNATSAS` |rightarrow| :menu:`Analyze All`

* Report automatically displayed based on user-specified filters

  * *Message Ranking* controls level of messages displayed
  * Other filters control types of messages and categories

.. image:: gnatsas/sas_report.png

*Report with* **Low,** **Medium,** *and* **High** *ranking messages*

==========
Analysis
==========

----------------
Analysis Modes
----------------

* Deals solely with *Inspector* engine

* :dfn:`Fast mode` 

  * Analyze each library unit separately
  * Allows for *incremental* analysis

    * Only units that change will be re-inspected

* :dfn:`Deep mode`

  * Analyzes groups of unit

    * Partitioning options to determine size of group

  * Analysis always starts from scratch

* Each mode has its own :dfn:`baseline`

-----------
Timelines
-----------

* Default: Separate baselines for comparing *deep* or *fast* runs

* Custom timelines available

  * :command:`timeline <name>` switch to create custom baseline
  * First execution becomes baseline for that name
  * Allows creating specialized timelines based on switches

    * Such as :command:`no-subprojects` which might drastically change number of messages

==========
Settings
==========

-------------------
Analysis Settings
-------------------

* Filters can remove uninteresting messages

  * e.g. :command:`show` to control messages to be displayed

* Skip problematic source files

  * *Excluded_Source_Files* project attribute
  * :ada:`pragma Annotate (GNATSAS, Skip_Analysis);` embedded in code

----------------------
Performance Settings
----------------------

* Simplistic methods

  * Disable specific analysis engine(s)
  * :command:`-j0` jobs switch
  * High-performance machines (multiple cores, etc)

* Identifying problematic units

  * For *Inspector*, examine output for units taking a long time

    | ``analyzed main.scil in 0.05 seconds``
    | ``analyzed main__body.scil in 620.31 seconds`` :math:`\leftarrow`
    | ``analyzed pack1__body.scil in 20.02 seconds``
    | ``analyzed pack2__body.scil in 5.13 seconds``

  * For *Infer*, use progress bar to see where the process is slow

    :command:`-Q --progress-bar-style multiline`
