Chapter 17 Reactis for EML Plugin
The V2015 release of Reactis included a new product the Reactis for EML Plugin, which integrates with Reactis to offer white-box testing of the Embedded MATLAB (EML) portions of a model. When using the plugin, Reactis Tester will generate tests which attempt to exercise targets in EML code and Reactis Simulator will track and display the coverage status of EML code. The V2016 release of Reactis extends Simulator functionality to include basic debugging of EML code, including breakpoints, single-stepping, and the ability to view variable values.
Note that if not using the Reactis for EML Plugin, you can still test models with EML code, but the EML portions of a model will be treated as block boxes. They will be executed but coverage within EML code not be tracked or targeted by generated tests, and EML code will not be visible within Reactis Simulator.
EML can be introduced into a model in several ways:
REML is under active development toward the ultimate goal of supporting a very large subset of EML. Please send requests to Reactive Systems (email@example.com) if there are unsupported EML features you would like use.
Whether in white-box or black-box mode for EML, Reactis supports the same subset of EML. This subset is defined in Section 17.4.
17.1 Enabling the Reactis for EML Plugin
Enable the plugin by selecting File -> Global Settings..., selecting the Reactis for EML tab, and then in the resulting dialog (Figure 17.1) select Enable white-box analysis of Embedded MATLAB code (requires license for EML Plugin).
The other controls in this tab let you toggle the display of line numbers in the main panel, set the background color of the line number bar, and toggle and set the color for drawing a grid (alternating the background color of each line) in the main panel.
As shown in Figure 17.2, after enabling the EML Plugin, the EML code contained in a model element will be displayed in the Reactis main panel when the element is selected in the hierarchy panel. Since Simulink stores the EML code within the model’s .slx file, no special configuration is required within Reactis. Reactis automatically extracts the EML code from the .slx file. If this EML code from the .slx file calls external functions residing outside the .slx file in separate .m files, then the external functions should be identified within Reactis as described in Section 17.2.
17.2 External EML Functions
Simulink supports calling functions stored in .m files external to a model. To call such a function from a MATLAB Function block (or any EML embedded in the model e.g. Stateflow, Truth Tables, etc.) the .m file must reside in a folder which is included in the MATLAB path.
Reactis also supports external EML functions, but you must identify the .m files containing external functions called from your model. You enumerate the external EML functions from the External EML Functions pane of the Reactis Info File Editor (Opened by selecting Edit -> External EML Functions from the Reactis main window). After you list the functions here, Reactis lists them in the External EML Functions section of the hierarchy panel as shown in Figure 17.3. Additionally, Reactis will identify coverage targets withing the external functions, attempt to exercise those targets when generating tests, and allow you to step into the external functions when executing your model in Reactis Simulator.
17.3 EML Coverage Metrics
Reactis uses a number of different coverage metrics to measure how thoroughly a test or set of tests exercises a model. In general, coverage metrics record how many of a given class of coverage targets (model features such as Stateflow states, EML program statements, etc.) have been executed at least once. Coverage metrics may be visualized using Simulator and are central to test generation and model validation using Tester and Validator.
Chapter 6 describes the coverage metrics that are tracked within the Simulink and Stateflow portions of models. Those metrics include some which are specific to Simulink, some which appear only in Stateflow, and others which are generic and can appear in either Simulink or Stateflow. Three of the generic metrics are also tracked in the EML code portions of models by the Reactis for EML Plugin. These are decision coverage, condition coverage, and modified condition / decision coverage (MC/DC).
Decision coverage tracks whether each decision in a program has evaluated to both true and false. The program elements that the Reactis for EML Plugin identifies as decisions are the conditional expressions in if statements and while loops.
Condition coverage tracks whether each condition (atomic Boolean expression) in a decision has evaluated to both true and false.
For the definition of MC/DC coverage, please see Chapter 6.
Finally, in addition to these generic coverage metrics, the Reactis for EML Plugin also tracks statement coverage – whether or not each EML statement has been executed at least once.
17.3.1 Tracking Coverage in EML Code
In Reactis Simulator, when Coverage -> Show Details is selected, unexercised coverage targets in EML code are reported visually as shown in Figure 17.4. Any unexecuted EML statement is rendered in red. If a decision has not evaluated to true it has a thin red overline. If a decision has not evaluated to false it has a thin red underline. If a condition has not evaluated to true it has a thick red overline. If a condition has not evaluated to false it has a thick red underline. If a decision has not met the MC/DC criteria, then the text of the decision is displayed in red. The MC/DC-related coverage details associated with a decision (Figure 17.5) may be displayed by right clicking on the decision and selecting View Coverage Details. For a description of this dialog, please see Chapter 6.
Lines containing unexercised targets are distinguished by a a thin red bar which is drawn just to the right of the line number of that line.
17.3.2 Debugging EML Code
When the EML Plugin is enabled, Simulator will step seamlessly into EML code, as shown in Figure 17.6. The numbered items in Figure 17.6 are the primary debugging operations supported by Simulator. These operations are:
17.4 Subset of Embedded MATLAB Supported by Reactis
This section describes the subset of EML that constitutes REML. REML supports the following aspects of EML. Note that in some cases not all aspects of a feature are supported. For example, a function might not support all numbers and types of input arguments.
While REML generally supports the rich EML notation for defining matrices,
REML does impose some syntax restrictions. The most prominent restriction
is that if any element of a row is a non-trivial expression, then the row
must be delimited with commas instead of spaces. For example, if a = 5 and
b = 4 then
17.4.3 Control flow
17.4.4 User-defined functions, Subfunctions, and External Functions
17.4.5 Array indexing
17.4.6 Logical operators
17.4.7 Relational operators
17.4.8 Math operators
17.4.9 Math functions
17.4.10 Statistical functions
These functions support vector and matrix inputs, but not higher dimensional arrays.
17.4.11 Matrix operations
17.4.12 Element-wise array operations
17.4.13 Vector operations
17.4.14 Bit operation
17.4.15 Cast operations
17.4.16 String operations
17.4.17 Miscellaneous functions