Wednesday, January 17, 2018

DVKit: Setting up SystemVerilog Development



In my last post on DVKit, I described how Eclipse uses projects to group source files, and uses workspaces to organize the projects and settings for a given development session. In this post, I'll start to dig into the support that DVKit provides for developing SystemVerilog.

DVKit includes the SVEditor plugin (http://sveditor.org), an open source Eclipse plug-in for developing SystemVerilog files. SystemVerilog is an object-oriented language that has similarities to C++ and Java. Unlike C++ and Java, though, SystemVerilog has strong ordering dependencies between files. C++ files can be independently analyzed because each C++ source file must include its dependencies and specify the namespace its content is in (if any). Java is even a bit more structured, requiring the class name and file name to match, and (effectively) requiring the directory structure to match the package namespace structure.

In contrast, all content in a SystemVerilog package must effectively be included in a single file. The pre-processor provides a level of workaround to enable classes to be stored in a separate file from the package file that includes them. However, this all adds up to make setting up source analysis for a SystemVerilog file a bit more detail-oriented than for other source languages.

In this post, I'll walk through setting up an Eclipse (DVKit) project for the UBus example from the UVM-1.2 library. I downloaded UVM here.

Creating a SystemVerilog Project

As mentioned in the last post, Eclipse makes it easy to create a project around existing source code. In this case, we know we will be working with SystemVerilog source, so we start by creating a new SVE Project. The wizard is found inside the SVEditor category, as shown below.


After selecting the proper wizard for project creation, we need to specify the particulars of the project:



Specifically, in this case:
  • ubus -- The name of the project
  • c:\usr1\fun\dvkit\uvm-1.2\examples\integrated\ubus -- The location of the ubus project within the UVM tree

Specifying Root Files

Since the ubus project contains existing sources, we next want to specify the root files so they can be indexed. SystemVerilog files need to be parsed in a very specific order, so it's important to only process the top-level files.

To do this, we first create a New Filelist on the Filelists page of the new SVE Project wizard. The filelist can be named anything, but the default (sve.f) is fine.


The next page is where the magic happens. 
  • Select the check box next to the 'ubus' project. This will cause all files with a SystemVerilog suffix (.sv, .svh, etc) to be selected
  • Click on the 'Compute Filelist' button. This pre-processes all source files and eliminates any files that are included by another. 
  • The resulting root files are displayed in the Filelist Contents box

Checking out the new Project

At this point, we've specified the root files in our project in such a way that the SVEditor plug-in can locate and parse them. We can now click Finish on the wizard and see the completed project.

Hmm... Okay, so we have a problem. Seems some macros from the UVM library can't be located. Of course, this isn't really surprising given than we haven't told the SVEditor plug-in to parse the UVM files.

Adding External Sources

Eclipse provides several ways to reference project-external source files. The easiest in this case is to just add the UVM library to the filelist that we already created.

We edit the sve.f file that we created during the project-creation process, and add two absolute paths to where we unpacked the UVM bundle:
  • +incdir+<uvm_install>/src
  • <uvm_install>/src/uvm_pkg.sv
After saving the file, we now have a project without errors.

Results


The payoff for properly configuring our SystemVerilog source project is that we can more-productively work with our SystemVerilog sources. In the screenshot above, the hover pop-up is displaying the documentation for the uvm_driver class. 

In future blog posts I'll dig into more features of Eclipse, DVKit, and plug-ins like SVEditor. For now, just a reminder that you can always download the completely open source DVKit here.

Sunday, January 7, 2018

DVKit: Workspaces, Projects, and Legacy Code


In Part 1 of this series, I introduced DVKit, an Eclipse-based IDE for files types used by DV engineers. If you're used to editing your source files with a single-file editor like Vi/Vim or Emacs, moving to an integrated development environment can take some getting used to. Single-file editors don't require any context (in fact, do not take advantage of any context) beyond the file on which they have been invoked. In contrast, IDEs require context for a file in order to provide many of the project-centric features that they provide.

Eclipse, like many integrated development environments, provides a variety of flexible features with which to specify the context of the files being developed. In this post, I'll describe the best practice fundamentals I've developed over the years when setting up development projects. Future posts will explore a few additional features that are very helpful in some cases.


Projects 

Eclipse provides two fundamental features for working with code: projects and workspaces (shown above). A project is represented by a directory that includes the sources being developed and some meta-data files with information about the language (eg Java) being used and how that language should be processed (eg assume Java 7). Some of this information is captured in a file named '.project' that is present in all Eclipse projects, and some will be captured in toolchain-specific files.

An Eclipse session can have multiple projects open at any given time.

Workspaces

Eclipse uses a workspace to capture a development session. A workspace records the projects that are open, the windows that are open and their positions and sizes, etc. In contrast to projects, a workspace typically does not contain any actual code -- just the preferences and settings used while developing code.

Projects are associated with a workspace in two ways:
  • When a project is created, it is automatically added to the active workspace
  • An existing project can be imported into the active workspace
In both cases, a link is added from the workspace to where the project is located on the filesystem. The project and its files will be visible in the workspace, but you are actually editing the files within the project directory, as shown in the diagram above.



I typically create a workspace for each codeline that I'm working on. So, I might have a workspace for "sveditor-master" and one for "sveditor-fast-indexer".

Working with Existing Code

If you're getting started with an Eclipse-based IDE like DVKit, you likely have lots of existing code and no existing Eclipse projects. So where do you start? Well, the good news is that Eclipse projects fit very nicely around existing code. You just need to decide what the primary language for the project is, and create the right project.

Let's say I want to work on files from the Linux Device Tree Compiler (DTC), and that I've cloned a copy of the repository (git://git.kernel.org/pub/scm/utils/dtc/dtc.git) to c:/usr1/fun/dvkit/tutorial/dtc.
After launching DVKit, I would launch the 'New C Project' wizard (New->Project... ) to create a new project for editing C code.


The next wizard allows me to provide specifics about the project I want to work on.



  • What is the project named? 'dtc'
  • Where is it located? On the filesystem at c:/usr1/fun/dvkit/tutorial/dtc
  • How are the source files compiled? With a Makefile
After completing this wizard, the 'dtc' project will be visible in the workspace:



Now the source files from the 'dtc' project are visible in the workspace and available for editing. In the future, we can bring the 'dtc' project into another workspace by running the Eclipse Import wizard to import an existing project.

Conclusion

The Eclipse project construct allows project-specific settings to be associated with source code, while the workspace construct enables users to manage session-specific settings. Eclipse's ability to construct a project around existing source code makes it easy to use Eclipse to develop existing code.

As always, you can download the freely-available Eclipse-based DVKit here: https://sourceforge.net/projects/dvkit/files/

Tuesday, January 2, 2018

DVKit: More-productive Code Development for DV Engineers



If you're a design verification (DV) engineer, how many different languages do you code in every day? If you're like me, the number is significant. On any given day, I might find myself working on SystemVerilog, PERL, shell script, Makefile, even C++. Text editors like Vim and a host of others can edit any text file, and even provide some basic syntax coloring.

How Do Integrated Development Environments Help?

Integrated Developmene Environments (IDEs) provide features far beyond those provided by simple text editors. While a text editor is typically aware of the current file being edited, an IDE is aware of the files related to the current file being edited. An IDE typically provides syntax and semantic checking for code as it is developed, which results in more accurate code creation and fewer mistakes being discovered during compilation. An IDE also provides features for navigating across the content of the code being developed -- for example, navigating to the declaration of a class from its usage. IDEs also provide on-the-fly content assist based on the declarations in the code under development -- for example, prompting the user with the methods available in a specific class.

There are a number of IDEs available, but many tend to focus on a handful of languages. Visual Studio, for example, focuses on C, C++, and C#. NetBeans focuses on Java and web languages. With the large variety of languages used for design verification, we need an IDE with support for the same large variety of languages.

Eclipse

If you're looking for a true integrated development environment (IDE) for multiple languages, the Eclipse platform is a natural choice. Originally developed by IBM as an integrated development environment for Smalltalk and Java, Eclipse has evolved into an open source platform that supports development of a dizzying array of languages -- from Java to C++ to ANTLR and beyond. As an integrated development environment, Eclipse not only provides text editing and syntax highlighting, it provides support for easily navigating code structure. For example, navigating from where a field is used to where it was declared.

DVKit

I've used Eclipse as a primary development tool for the past 12 years or so. Eclipse follows a plug-in-based architecture, and makes it easy to install new plug-ins for developing various languages. So, it's not terribly difficult to "roll your own" installation of Eclipse that contains your favorite plug-ins. About four years ago, I realized that there were two challenges with continuing to roll my own. First, it was time consuming. Remembering the web sites for all my favorite plug-ins and installing them every time a new version of Eclipse was released, on every development machine I use, was a hassle. Second, I didn't have a good way to share my favorite collection of Eclipse plug-ins with others.

So, about four years ago I created DVKit. DVKit is based on Eclipse and packages all my favorite plug-ins for developing languages such as:
  • SystemVerilog
  • PERL
  • Python
  • Shell
  • C/C++
  • Java
  • Javascript
  • Scala
  • Makefile
  • TCL
  • XML
  • YAML
DVKit is available for Linux, Windows, and Mac OS-X. On Windows, an installer is available to make it extra simple.

You can find DVKit at http://dvkit.org, and the downloads page here.

Over the next few blog posts, I'll introduce you to the fundamentals of developing code with DVKit and Eclipse, and some of the language-specific features provided with DVKit. In the meantime, I would encourage you to download DVKit and begin to explore how an IDE can help boost your development productivity.