Compile and Run Hello World

Options for Compilation and Execution

• On campus you will use the comiler GNAT, a very high quality free compiler that is a component of the GNU open source gcc compiler


• Gnat is a compiler only. For the full cycle of editing, compiling, and running your program, you will also need an IDE or an editor.


• In campus labs you will have three options for the IDE or editor:
1. AdaGIDE - an easy to use IDE
2. Gnatbench - An Eclipse Plugin
3. GPS - a more complex and more powerful IDE
4. Command Line (ie separate editor and compiler)


• Information on using each of these is below


• Information for installing these on your home machine are here.

hello.adb

• Here is a sample Ada program to compile and run, Hello World:

    with ada.text_io;   -- Tell compiler to use i/o library
    use  ada.text_io;   -- Use library routines w/o fully qualified names
    procedure hello is
    begin
        put("Hi 320");
    end hello; 

• Filename: hello.adb

Using AdaGIDE

• AdaGIDE is a simple IDE


• It provides autocompletion and access to the gdb debugger


• AdaGIDE is Windows only


• Available on campus at: Start/Programs/RUCourseSW/CST/Ada IDE/adagide
• May not be available on machines with smaller hard drives


• Steps to create, compile, and run
• Create w/ File/New


• Enter program


• Save to file hello.adb with File/Save


• Compile with Compile/Build (F3)


• Run with Run/Execute (F4)

Using Gnatbench on Eclipse

• Use menu item Project/Build Current Project or Project Rebuild Current Project to check for syntax errors and generate executable code


• The Build All icon checks for syntax errors, but only seems to generate executable code the first time it is used


• The Project/Build All and Project/Build Project menu items check for syntax errors but don't generate executable code


• My experience with Eclipse is limited. If you can provide me with more information on using Gnatbench, I'd appreciate it.

Using GPS

• GPS is a more complex and more powerful IDE


• It provides a powerful interface to the debugger and has identifier completion


• GPS has versions for Windows and Linux


• GPS is based on projects. A project is defined by a project file (eg yourProj.gpr) which contains information such as
  • The files that are used by the project
  • The directories where those files are stored
  • Which file is the Main file (ie where execution begins)
  • What compiler options are to be used during compilation


• Steps to create a project and to create, compile, and run a program file
1. Run GPS: Start/Programs/RUCourseSW/CST/Ada IDE/GPL_2007/GPS


2. On the startup screen, select "Start with default project in directory:", set the directory where you want to store the project, and press OK


3. Create your program by selecting File/New and then entering the program.
• To get syntax highlighting and indenting when you first type your program, you should save the (empty) file so that GPS knows that this an Ada file. To save, use File/Save and save it as yourName.adb.


4. Set your program as the main file by doing Project/Edit Project Properties and select the tab for "Main files", and then select Add to add your file as the main program


5. Compile your program with Build/Make/yourFile.adb


6. Run your program with Build/Run
• If you want to rename your project, you can change the name under the General tab of Project/Edit Project Properties, and then save the new project file. The old project file will still exist.

Creating a new project with GPS

• Select "Creating a new project with wizard"
• Select Project/New Project
• Steps with the wizard (press "Forward" after each step, and watch your progress in the left panel):
• Select "Single Project"
• Choose a name for your project (eg project1) and the directory where the project will be created (eg on your desktop)
• The project will consist of a project file (eg project1..gpr, your program (eg hello.adb), and the files that result from compilation (eg hello.o, hello.ali, hello.exe)
• Accept the choice of the language Ada
• Accept the VCS screen
• Accept the default source directory (eg your deskop)
• Enter the build directory (eg Desktop) - this is where .o, .ali, and .exe files will appear. (You may press apply at this point or continue with the remaining screens)
• Accept the blank "Main files" screen
• Accept the default "Naming scheme"
• Accept the default switches

Other IDEs

• JGrasp is an interesting IDE that provides various visualizations of your program. Handles Ada and Java.

Command Line

• To use the command line, you must first use an editor to create hello.adb:
• Possible editors include vim, gvim, jedit, pico, pfe, ...


• To compile hello.adb use this command:

      gnatmake hello 

• You can also say gnatmake hello.adb


• To run your program use this command:

    hello
    

• On windows, the command hello.exe also works

How to get a Command Line Window

• On Windows you can create a command window with Start/Run/Cmd


• On Windows you can also start a secure shell session to rucs, as follows:
• Start a secure shell client: Start/RUNetwork/SSH Secure Shell/Secure Shell Client
• Start a session to rucs.radford.edu


• Linux machines: a terminal window provides a command line
• Linux machines can also run secure shell to connect to rucs, as follows: ssh rucs


• Macs: similar to above

Installing compilers at home

• Information on installing at home is here.

Using a debugger

• Each of the environments (AdaGIDE, Eclipse, GPS, command line) has a way of using the debugger with Ada.
• Here are some instructions.

Files Created by Compilation

• Gnatmake creates the following files


• Library Information file (eg sayhi.ali): describes when compilation occurred and any file dependencies


• Object file (eg sayhi.o): contains non-executable machine code, but does not contain code for library routines)


• Executable file (sayhi.exe in Windows, sayhi in linux): executable machine code (all libraries are linked in)


• The .ali and .o files are not needed after the executable is created.