4. Configuration

We will show you how to prepare your project for use with FlowSpec, and write your first small specification.

4.1. Prepare your project

You can start using FlowSpec by creating a new project, or by modifying an existing project. See below for the steps for your case.

4.1.1. Start a new project

If you have not done this already, install Spoofax Eclipse, by following the installation instructions.

Create a new project by selecting New > Project... from the menu. Selecting Spoofax > Spoofax language project from the list, and click Next. After filling in a project name, an identifier, name etc will be automatically suggested. Select NaBL2 as the analysis type, FlowSpec builds on top of NaBL2’s analysis infrastructure. Click Finish to create the project.

Add the following dependencies in the metaborg.yaml file:

---
# ...
dependencies:
  compile:
  - org.metaborg:flowspec.lang:${metaborgVersion}
  source:
  - org.metaborg:flowspec.lang:${metaborgVersion}

Add menus to access the result of analysis, by adding the following import to editor/Main.esv.

module Main

imports

  flowspec/Menus

4.1.2. Convert an existing project

If you have an existing project, and you want to start using FlowSpec, there are a few changes you need to make.

First of all, make sure the metaborg.yaml file contains at least the following dependencies.

---
# ...
dependencies:
  compile:
  - org.metaborg:org.metaborg.meta.nabl2.lang:${metaborgVersion}
  - org.metaborg:flowspec.lang:${metaborgVersion}
  source:
  - org.metaborg:org.metaborg.meta.nabl2.shared:${metaborgVersion}
  - org.metaborg:org.metaborg.meta.nabl2.runtime:${metaborgVersion}
  - org.metaborg:flowspec.lang:${metaborgVersion}

We will set things up, such that analysis rules will be grouped together in the directory trans/analysis. Create a file trans/analysis/main.str that contains the following.

module analysis/main

imports

  nabl2shared
  nabl2runtime
  analysis/-

Add the following lines to your main trans/LANGUAGE.str.

module LANGUAGE

imports

  analysis/main

rules

  editor-analyze = nabl2-analyze(desugar-pre)

If your language does not have a desugaring step, use nabl2-analyze(id) instead.

Add an NaBL2 specification. The most minimal one is the following.

module analysis/minimal

rules

init.

[[ _ ]].

Running and integrating the FlowSpec analysis is explained on the Stratego API page.

Finally, we will add reference resolution and menus to access the result of analysis, by adding the following lines to editor/Main.esv.

module Main

imports

  nabl2/References
  nabl2/Menus
  flowspec/Menus

You can now continue to the example specification here, or directly to the language reference.

4.2. Inspecting analysis results

You can debug your specification by inspecting the result of analysis, and by logging a trace of the rules that get applied during constraint generation.

The result of analysis can be inspected, by selecting elements from the Spoofax > FlowSpec Analysis the menu. For multi-file projects, use the Project results, or the File results for single-file projects. The result is given as a control-flow graph annotated with data-flow properties in the DOT format used by GraphViz. If you have GraphViz installed, you can set the dot executable in the settings of the graphviz editor to allow you to jump straight from Eclipse to the rendered graph.