F. Development Tools

Here are some tools that you might find useful while developing code.

F.1 Tags

Tags are an index to the functions and global variables declared in a program. Many editors, including Emacs and vi, can use them. The Makefile in pintos/src produces Emacs-style tags with the command make TAGS or vi-style tags with make tags.

In Emacs, use M-. to follow a tag in the current window, C-x 4 . in a new window, or C-x 5 . in a new frame. If your cursor is on a symbol name for any of those commands, it becomes the default target. If a tag name has multiple definitions, M-0 M-. jumps to the next one. To jump back to where you were before you followed the last tag, use M-*.

F.2 Eclipse

If you feel more comfortable using a GUI for debugging, you can use any GDB frontend that supports remote sessions, for example Eclipse. We present instructions on how to debug pintos in Eclipse IDE.

First, you will need an Eclipse build with C/C++ support, it can be downloaded from: http://www.eclipse.org/downloads/. Then, proceed as follows:

• The pintos tarball already contains an Eclipse project. Extract the tarball into a directory without any spaces or special characters in name (i.e. no spaces, colons etc.), e.g. into /home/me/os/pintos.

• Next, do the following sequence of commands:

  cd mkdir os cd os tar xvf ~/pintos.tar.gz ls pintos/

• Start Eclipse and choose "File -> Import..." from the main menu.

• In the "Import" dialog, select "General -> Existing Projects into Workspace" and click "Next".

• Choose the pintos directory for the "Root directory".

• You should see the pintos project in the list of projects, make sure it is checked and press "Finish".

• Now you should see the newly added pintos project in the "Project Explorer", select it and choose "Project -> Build Project" from the main menu. Eclipse will call "make" to build the pintos source, it will take a while.

In the following, we will assume you want to debug the first assignment.

• Choose "Run -> Debug Configurations..." from the main menu

• In the "Debug Configurations" dialog, select "C/C++ Local Application" from the list and click the "New launch configuration" button.

• Enter a name for the configuration, e.g. "pintos threads".

• Select "pintos" project for the "Project" field.

• On the "Main" tab, use the "Browse" button to enter /home/me/os/pintos/src/threads/build/kernel.o into the "C/C++ Application" field ("Search Project" will not work, since there are no binaries).

• Make sure the "Connect input & output to a terminal" checkbox is checked.

• On the "Debugger" tab, select "gdbserver Debugger" as "Debugger".

• If you want to see what gdb commands are called (useful if it doesn't work), check the "Verbose console mode" checkbox on the "Main" tab of "Debugger Options".

• Under "Debugger Options", on the "Connection" tab: select "TCP" as "Type", "localhost" as the hostname and "1234" as the port number.

• Click "Apply" to save the changes.

• Open a terminal and go to /home/me/os/pintos/src/threads/build"

• Make sure the Bochs executable, as well as the "pintos" script from /home/me/os/pintos/src/utils is in your PATH

• Start some test with --gdb option, e.g. pintos --gdb -- run alarm-multiple

• Bochs should start, open a window and print "Waiting for gdb connection on port 1234" message to console.

• Switch back to Eclipse and start debugging the "pintos threads" configuration as usual.

F.3 SourceForge

SourceForge is a web-based system for facilitating software development. It provides you with a version-control system (typically SVN) and other tools for tracking your software. You can use it to store files, track bugs, and post notes about development progress. You can set up your own project in SourceForge at sourceforge.net.

F.4 cscope

The cscope program also provides an index to functions and variables declared in a program. It has some features that tag facilities lack. Most notably, it can find all the points in a program at which a given function is called.

The Makefile in pintos/src produces cscope indexes when it is invoked as make cscope. Once the index has been generated, run cscope from a shell command line; no command-line arguments are normally necessary. Then use the arrow keys to choose one of the search criteria listed near the bottom of the terminal, type in an identifier, and hit Enter. cscope will then display the matches in the upper part of the terminal. You may use the arrow keys to choose a particular match; if you then hit Enter, cscope will invoke the default system editor (typically vi) and position the cursor on that match. To start a new search, type Tab. To exit cscope, type Ctrl-d.

Emacs and some versions of vi have their own interfaces to cscope. For information on how to use these interface, visit http://cscope.sourceforge.net, the cscope home page.

F.5 Git

It's crucial that you use a source code control system to manage your Pintos code. This will allow you to keep track of your changes and coordinate changes made by different people in the project. For this class we recommend that you use Git; if you followed the instructions on getting started, a Git repository will already have been created for you. If you don't already know how to use Git, we recommend that you read the Pro Git book online.

F.6 VNC

VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing "desktop" environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. For more information, look at the VNC Home Page.